correct version 1.70

improved array literal datatype detection

.gitignore

@@ -1,4 +1,5 @@
 .idea/workspace.xml
+.idea/discord.xml
 /build/
 /dist/
 /output/
@@ -24,8 +25,6 @@ __pycache__/
 parser.out
 parsetab.py
 .pytest_cache/
-compiler/src/prog8_kotlin.jar
-compiler/src/compiled_java
 .attach_pid*
 
 .gradle

.idea/.gitignore

@@ -0,0 +1,2 @@
+# Default ignored files
+/shelf/

.idea/dictionaries/irmen.xml

@@ -0,0 +1,3 @@
+<component name="ProjectDictionaryState">
+  <dictionary name="irmen" />
+</component>

.idea/inspectionProfiles/Project_Default.xml

@@ -0,0 +1,20 @@
+<component name="InspectionProjectProfileManager">
+  <profile version="1.0">
+    <option name="myName" value="Project Default" />
+    <inspection_tool class="DuplicatedCode" enabled="true" level="WEAK WARNING" enabled_by_default="true">
+      <Languages>
+        <language minSize="100" isEnabled="false" name="JavaScript" />
+        <language isEnabled="false" name="Groovy" />
+        <language isEnabled="false" name="Style Sheets" />
+        <language minSize="70" name="Kotlin" />
+        <language isEnabled="false" name="TypeScript" />
+        <language isEnabled="false" name="ActionScript" />
+      </Languages>
+    </inspection_tool>
+    <inspection_tool class="SpellCheckingInspection" enabled="true" level="TYPO" enabled_by_default="true">
+      <option name="processCode" value="false" />
+      <option name="processLiterals" value="true" />
+      <option name="processComments" value="false" />
+    </inspection_tool>
+  </profile>
+</component>

.idea/libraries/antlr_4_8_complete.xml

@@ -0,0 +1,9 @@
+<component name="libraryTable">
+  <library name="antlr-4.8-complete">
+    <CLASSES>
+      <root url="jar://$PROJECT_DIR$/parser/antlr/lib/antlr-4.8-complete.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>

.idea/libraries/antlr_runtime_4_8.xml

@@ -0,0 +1,9 @@
+<component name="libraryTable">
+  <library name="antlr-runtime-4.8">
+    <CLASSES>
+      <root url="jar://$PROJECT_DIR$/parser/antlr/lib/antlr-runtime-4.8.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>

.idea/libraries/kotlinx_cli_jvm_0_1_0_dev_5.xml

@@ -0,0 +1,9 @@
+<component name="libraryTable">
+  <library name="kotlinx-cli-jvm-0.1.0-dev-5">
+    <CLASSES>
+      <root url="jar://$PROJECT_DIR$/compiler/lib/kotlinx-cli-jvm-0.1.0-dev-5.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>

.idea/markdown-navigator-enh.xml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="MarkdownEnhProjectSettings">
+    <AnnotatorSettings targetHasSpaces="true" linkCaseMismatch="true" wikiCaseMismatch="true" wikiLinkHasDashes="true" notUnderWikiHome="true" targetNotWikiPageExt="true" notUnderSourceWikiHome="true" targetNameHasAnchor="true" targetPathHasAnchor="true" wikiLinkHasSlash="true" wikiLinkHasSubdir="true" wikiLinkHasOnlyAnchor="true" linkTargetsWikiHasExt="true" linkTargetsWikiHasBadExt="true" notUnderSameRepo="true" targetNotUnderVcs="false" linkNeedsExt="true" linkHasBadExt="true" linkTargetNeedsExt="true" linkTargetHasBadExt="true" wikiLinkNotInWiki="true" imageTargetNotInRaw="true" repoRelativeAcrossVcsRoots="true" multipleWikiTargetsMatch="true" unresolvedLinkReference="true" linkIsIgnored="true" anchorIsIgnored="true" anchorIsUnresolved="true" anchorLineReferenceIsUnresolved="true" anchorLineReferenceFormat="true" anchorHasDuplicates="true" abbreviationDuplicates="true" abbreviationNotUsed="true" attributeIdDuplicateDefinition="true" attributeIdNotUsed="true" footnoteDuplicateDefinition="true" footnoteUnresolved="true" footnoteDuplicates="true" footnoteNotUsed="true" macroDuplicateDefinition="true" macroUnresolved="true" macroDuplicates="true" macroNotUsed="true" referenceDuplicateDefinition="true" referenceUnresolved="true" referenceDuplicates="true" referenceNotUsed="true" referenceUnresolvedNumericId="true" enumRefDuplicateDefinition="true" enumRefUnresolved="true" enumRefDuplicates="true" enumRefNotUsed="true" enumRefLinkUnresolved="true" enumRefLinkDuplicates="true" simTocUpdateNeeded="true" simTocTitleSpaceNeeded="true" />
+    <HtmlExportSettings updateOnSave="false" parentDir="" targetDir="" cssDir="css" scriptDir="js" plainHtml="false" imageDir="" copyLinkedImages="false" imagePathType="0" targetPathType="2" targetExt="" useTargetExt="false" noCssNoScripts="false" useElementStyleAttribute="false" linkToExportedHtml="true" exportOnSettingsChange="true" regenerateOnProjectOpen="false" linkFormatType="HTTP_ABSOLUTE" />
+    <LinkMapSettings>
+      <textMaps />
+    </LinkMapSettings>
+  </component>
+  <component name="MarkdownNavigatorHistory">
+    <PasteImageHistory checkeredTransparentBackground="false" filename="image" directory="" onPasteImageTargetRef="3" onPasteLinkText="0" onPasteImageElement="1" onPasteLinkElement="1" onPasteReferenceElement="2" cornerRadius="20" borderColor="0" transparentColor="16777215" borderWidth="1" trimTop="0" trimBottom="0" trimLeft="0" trimRight="0" transparent="false" roundCorners="false" showPreview="true" bordered="false" scaled="false" cropped="false" hideInapplicableOperations="false" preserveLinkFormat="false" scale="50" scalingInterpolation="1" transparentTolerance="0" saveAsDefaultOnOK="false" linkFormat="0" addHighlights="false" showHighlightCoordinates="true" showHighlights="false" mouseSelectionAddsHighlight="false" outerFilled="false" outerFillColor="0" outerFillTransparent="true" outerFillAlpha="30">
+      <highlightList />
+      <directories />
+      <filenames />
+    </PasteImageHistory>
+    <CopyImageHistory checkeredTransparentBackground="false" filename="image" directory="" onPasteImageTargetRef="3" onPasteLinkText="0" onPasteImageElement="1" onPasteLinkElement="1" onPasteReferenceElement="2" cornerRadius="20" borderColor="0" transparentColor="16777215" borderWidth="1" trimTop="0" trimBottom="0" trimLeft="0" trimRight="0" transparent="false" roundCorners="false" showPreview="true" bordered="false" scaled="false" cropped="false" hideInapplicableOperations="false" preserveLinkFormat="false" scale="50" scalingInterpolation="1" transparentTolerance="0" saveAsDefaultOnOK="false" linkFormat="0" addHighlights="false" showHighlightCoordinates="true" showHighlights="false" mouseSelectionAddsHighlight="false" outerFilled="false" outerFillColor="0" outerFillTransparent="true" outerFillAlpha="30">
+      <highlightList />
+      <directories />
+      <filenames />
+    </CopyImageHistory>
+    <PasteLinkHistory onPasteImageTargetRef="3" onPasteTargetRef="1" onPasteLinkText="0" onPasteImageElement="1" onPasteLinkElement="1" onPasteWikiElement="2" onPasteReferenceElement="2" hideInapplicableOperations="false" preserveLinkFormat="false" useHeadingForLinkText="false" linkFormat="0" saveAsDefaultOnOK="false" />
+    <TableToJsonHistory>
+      <entries />
+    </TableToJsonHistory>
+    <TableSortHistory>
+      <entries />
+    </TableSortHistory>
+  </component>
+</project>

.idea/markdown-navigator.xml

@@ -0,0 +1,57 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="FlexmarkProjectSettings">
+    <FlexmarkHtmlSettings flexmarkSpecExampleRendering="0" flexmarkSpecExampleRenderHtml="false">
+      <flexmarkSectionLanguages>
+        <option name="1" value="Markdown" />
+        <option name="2" value="HTML" />
+        <option name="3" value="flexmark-ast:1" />
+      </flexmarkSectionLanguages>
+    </FlexmarkHtmlSettings>
+  </component>
+  <component name="MarkdownProjectSettings">
+    <PreviewSettings splitEditorLayout="SPLIT" splitEditorPreview="PREVIEW" useGrayscaleRendering="false" zoomFactor="1.0" maxImageWidth="0" synchronizePreviewPosition="true" highlightPreviewType="LINE" highlightFadeOut="5" highlightOnTyping="true" synchronizeSourcePosition="true" verticallyAlignSourceAndPreviewSyncPosition="true" showSearchHighlightsInPreview="true" showSelectionInPreview="true" lastLayoutSetsDefault="false">
+      <PanelProvider>
+        <provider providerId="com.vladsch.md.nav.editor.javafx.html.panel" providerName="JavaFX WebView" />
+      </PanelProvider>
+    </PreviewSettings>
+    <ParserSettings gitHubSyntaxChange="false" correctedInvalidSettings="false" emojiShortcuts="1" emojiImages="0">
+      <PegdownExtensions>
+        <option name="ANCHORLINKS" value="true" />
+        <option name="ATXHEADERSPACE" value="true" />
+        <option name="FENCED_CODE_BLOCKS" value="true" />
+        <option name="INTELLIJ_DUMMY_IDENTIFIER" value="true" />
+        <option name="RELAXEDHRULES" value="true" />
+        <option name="STRIKETHROUGH" value="true" />
+        <option name="TABLES" value="true" />
+        <option name="TASKLISTITEMS" value="true" />
+      </PegdownExtensions>
+      <ParserOptions>
+        <option name="COMMONMARK_LISTS" value="true" />
+        <option name="EMOJI_SHORTCUTS" value="true" />
+        <option name="GFM_TABLE_RENDERING" value="true" />
+        <option name="PRODUCTION_SPEC_PARSER" value="true" />
+        <option name="SIM_TOC_BLANK_LINE_SPACER" value="true" />
+      </ParserOptions>
+    </ParserSettings>
+    <HtmlSettings headerTopEnabled="false" headerBottomEnabled="false" bodyTopEnabled="false" bodyBottomEnabled="false" addPageHeader="false" imageUriSerials="false" addDocTypeHtml="true" noParaTags="false" plantUmlConversion="0">
+      <GeneratorProvider>
+        <provider providerId="com.vladsch.md.nav.editor.javafx.html.generator" providerName="JavaFx HTML Generator" />
+      </GeneratorProvider>
+      <headerTop />
+      <headerBottom />
+      <bodyTop />
+      <bodyBottom />
+    </HtmlSettings>
+    <CssSettings previewScheme="UI_SCHEME" cssUri="" isCssUriEnabled="false" isCssUriSerial="true" isCssTextEnabled="false" isDynamicPageWidth="true">
+      <StylesheetProvider>
+        <provider providerId="com.vladsch.md.nav.editor.javafx.html.css" providerName="Default JavaFx Stylesheet" />
+      </StylesheetProvider>
+      <ScriptProviders>
+        <provider providerId="com.vladsch.md.nav.editor.hljs.html.script" providerName="HighlightJS Script" />
+      </ScriptProviders>
+      <cssText />
+      <cssUriHistory />
+    </CssSettings>
+  </component>
+</project>

.idea/misc.xml

@@ -1,5 +1,21 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="ANTLRGenerationPreferences">
+    <option name="perGrammarGenerationSettings">
+      <list>
+        <PerGrammarGenerationSettings>
+          <option name="fileName" value="$PROJECT_DIR$/parser/antlr/prog8.g4" />
+          <option name="autoGen" value="true" />
+          <option name="outputDir" value="$PROJECT_DIR$/parser/src/prog8/parser" />
+          <option name="libDir" value="" />
+          <option name="encoding" value="" />
+          <option name="pkg" value="" />
+          <option name="language" value="" />
+          <option name="generateListener" value="false" />
+        </PerGrammarGenerationSettings>
+      </list>
+    </option>
+  </component>
   <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="false" project-jdk-name="Kotlin SDK" project-jdk-type="KotlinSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>

.idea/vcs.xml

@@ -3,4 +3,4 @@
   <component name="VcsDirectoryMappings">
     <mapping directory="$PROJECT_DIR$" vcs="Git" />
   </component>
-</project>
+</project>

.travis.yml

@@ -1,11 +1,11 @@
 language: java
+sudo: false
 # jdk: openjdk8
 # dist: xenial
-# sudo: false
 
 before_install:
   - chmod +x gradlew
 
 script:
-  - ./gradlew test
+  - gradle test
 

README.md

@@ -14,35 +14,39 @@ as used in many home computers from that era. It is a medium to low level progra
 which aims to provide many conveniences over raw assembly code (even when using a macro assembler):
 
 - reduction of source code length
-- easier program understanding (because it's higher level, and way more compact)
 - modularity, symbol scoping, subroutines
-- subroutines have enforced input- and output parameter definitions
-- various data types other than just bytes (16-bit words, floats, strings, 16-bit register pairs)
-- automatic variable allocations, automatic string variables and string sharing
-- constant folding in expressions (compile-time evaluation)
+- various data types other than just bytes (16-bit words, floats, strings)
+- automatic variable allocations, automatic string and array variables and string sharing
+- subroutines with a input- and output parameter signature
+- constant folding in expressions
 - conditional branches
-- automatic type conversions
-- floating point operations  (uses the C64 Basic ROM routines for this)
+- 'when' statement to provide a concise jump table alternative to if/elseif chains
+- structs to group together sets of variables and manipulate them at once
+- floating point operations  (requires the C64 Basic ROM routines for this)
 - abstracting away low level aspects such as ZeroPage handling, program startup, explicit memory addresses
-- various code optimizations (code structure, logical and numerical expressions, unused code removal...) 
+- various code optimizations (code structure, logical and numerical expressions, unused code removal...)
+- inline assembly allows you to have full control when every cycle or byte matters
+- many built-in functions such as ``sin``, ``cos``, ``rnd``, ``abs``, ``min``, ``max``, ``sqrt``, ``msb``, ``rol``, ``ror``, ``swap``, ``memset``, ``memcopy``, ``sort`` and ``reverse``
 
 Rapid edit-compile-run-debug cycle:
 
-- use modern PC to work on 
-- quick compilation times (less than 1 second)
-- option to automatically run the program in the Vice emulator  
+- use modern PC to work on
+- quick compilation times (seconds)
+- option to automatically run the program in the Vice emulator
 - breakpoints, that let the Vice emulator drop into the monitor if execution hits them
 - source code labels automatically loaded in Vice emulator so it can show them in disassembly
-
+- virtual machine that can execute compiled code directy on the host system,
+  without having to actually convert it to assembly to run on a real 6502
 
 It is mainly targeted at the Commodore-64 machine at this time.
 Contributions to add support for other 8-bit (or other?!) machines are welcome.
 
-Documentation is online at https://prog8.readthedocs.io/
+Documentation/manual
+--------------------
+This describes the language, but also how to build and run the compiler. See https://prog8.readthedocs.io/
 
-
-Required tools:
----------------
+Required tools
+--------------
 
 [64tass](https://sourceforge.net/projects/tass64/) - cross assembler. Install this on your shell path.
 A recent .exe version of this tool for Windows can be obtained from my [clone](https://github.com/irmen/64tass/releases) of this project.
@@ -64,7 +68,7 @@ This code calculates prime numbers using the Sieve of Eratosthenes algorithm::
     %import c64utils
     %zeropage basicsafe
 
-    ~ main {
+    main {
 
         ubyte[256] sieve
         ubyte candidate_prime = 2

clean.sh

@@ -1,5 +0,0 @@
-#!/usr/bin/env sh
-
-rm *.jar *.asm *.prg *.vm.txt *.vice-mon-list
-rm -r build
-

compiler/build.gradle

@@ -1,38 +1,61 @@
+buildscript {
+    dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.61"
+    }
+}
+
 plugins {
-    id "org.jetbrains.kotlin.jvm" version "1.3.40"
+    // id "org.jetbrains.kotlin.jvm" version "1.3.61"
     id 'application'
     id 'org.jetbrains.dokka' version "0.9.18"
+    id 'com.github.johnrengelman.shadow' version '5.2.0'
+    id 'java'
 }
 
+apply plugin: "kotlin"
+apply plugin: "java"
+
+targetCompatibility = 1.8
+sourceCompatibility = 1.8
+
 repositories {
+    mavenLocal()
     mavenCentral()
     jcenter()
+    maven { url "https://dl.bintray.com/orangy/maven/" }
 }
 
-def kotlinVersion = '1.3.40'
+def prog8version = rootProject.file('compiler/res/version.txt').text.trim()
 
 dependencies {
     implementation project(':parser')
-    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlinVersion"
-    implementation "org.jetbrains.kotlin:kotlin-reflect:$kotlinVersion"
-    runtime "org.jetbrains.kotlin:kotlin-reflect:$kotlinVersion"
-    runtime 'org.antlr:antlr4-runtime:4.7.2'
-    runtime project(':parser')
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
+    // implementation "org.jetbrains.kotlin:kotlin-reflect"
+    implementation 'org.antlr:antlr4-runtime:4.8'
+    implementation 'org.jetbrains.kotlinx:kotlinx-cli-jvm:0.1.0-dev-5'
+    // implementation 'net.razorvine:ksim65:1.6'
+    implementation project(':parser')
 
-    testImplementation "org.jetbrains.kotlin:kotlin-test-junit5:$kotlinVersion"
+    testImplementation "org.jetbrains.kotlin:kotlin-test-junit5"
     testImplementation 'org.junit.jupiter:junit-jupiter-api:5.3.2'
     testImplementation 'org.hamcrest:hamcrest-junit:2.0.0.0'
-
     testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.3.2'
 }
 
 compileKotlin {
     kotlinOptions {
         jvmTarget = "1.8"
+        // verbose = true
         // freeCompilerArgs += "-XXLanguage:+NewInference"
     }
 }
 
+compileTestKotlin {
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
+}
+
 sourceSets {
     main {
         java {
@@ -49,42 +72,25 @@ sourceSets {
     }
 }
 
-
+startScripts.enabled = true
 
 application {
     mainClassName = 'prog8.CompilerMainKt'
     applicationName = 'p8compile'
 }
 
-task p8vmScript(type: CreateStartScripts) {
-    mainClassName = "prog8.StackVmMainKt"
-    applicationName = "p8vm"
-    outputDir = new File(project.buildDir, 'scripts')
-    classpath = jar.outputs.files + project.configurations.runtime
+artifacts {
+    archives shadowJar
 }
 
-applicationDistribution.into("bin") {
-    from(p8vmScript)
-    fileMode = 0755
-}
 
-task fatJar(type: Jar) {
-    manifest {
-        attributes 'Main-Class': 'prog8.CompilerMainKt'
-    }
+shadowJar {
     archiveBaseName = 'prog8compiler'
-    destinationDirectory = rootProject.projectDir
-    from {
-        project.configurations.runtime.collect { it.isDirectory() ? it : zipTree(it) }
-    }
-    with jar
+    archiveVersion = prog8version
+    // minimize()
 }
-// build.finalizedBy(fatJar)
 
 
-// Java target version
-sourceCompatibility = 1.8
-
 test {
     // Enable JUnit 5 (Gradle 4.6+).
     useJUnitPlatform()

compiler/compiler.iml

@@ -8,12 +8,12 @@
       <sourceFolder url="file://$MODULE_DIR$/test" isTestSource="true" />
       <excludeFolder url="file://$MODULE_DIR$/build" />
     </content>
-    <orderEntry type="jdk" jdkName="1.8" jdkType="JavaSDK" />
+    <orderEntry type="jdk" jdkName="openjdk-11" jdkType="JavaSDK" />
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="library" name="KotlinJavaRuntime" level="project" />
-    <orderEntry type="library" name="KotlinJavaRuntime" level="project" />
-    <orderEntry type="library" name="antlr-runtime-4.7.2" level="project" />
     <orderEntry type="module" module-name="parser" />
     <orderEntry type="library" name="unittest-libs" level="project" />
+    <orderEntry type="library" name="kotlinx-cli-jvm-0.1.0-dev-5" level="project" />
+    <orderEntry type="library" name="antlr-runtime-4.8" level="project" />
   </component>
 </module>

compiler/res/prog8lib/c64flt.p8

@@ -7,7 +7,7 @@
 %option enable_floats
 
 
-~ c64flt {
+c64flt {
 	; ---- this block contains C-64 floating point related functions ----
 
 		const  float  PI	= 3.141592653589793
@@ -41,25 +41,25 @@
 ; note: for subtraction and division, the left operand is in fac2, the right operand in fac1.
 
 ; checked functions below:
-asmsub	MOVFM		(uword mflpt @ AY) -> clobbers(A,Y) -> ()	= $bba2		; load mflpt value from memory  in A/Y into fac1
-asmsub	FREADMEM	() -> clobbers(A,Y) -> ()			= $bba6		; load mflpt value from memory  in $22/$23 into fac1
-asmsub	CONUPK		(uword mflpt @ AY) -> clobbers(A,Y) -> ()	= $ba8c		; load mflpt value from memory  in A/Y into fac2
-asmsub	FAREADMEM	() -> clobbers(A,Y) -> ()			= $ba90		; load mflpt value from memory  in $22/$23 into fac2
-asmsub	MOVFA		() -> clobbers(A,X) -> ()			= $bbfc		; copy fac2 to fac1
-asmsub	MOVAF		() -> clobbers(A,X) -> ()			= $bc0c		; copy fac1 to fac2  (rounded)
-asmsub	MOVEF		() -> clobbers(A,X) -> ()			= $bc0f		; copy fac1 to fac2
-asmsub	MOVMF		(uword mflpt @ XY) -> clobbers(A,Y) -> ()	= $bbd4		; store fac1 to memory  X/Y as 5-byte mflpt
+asmsub	MOVFM		(uword mflpt @ AY) clobbers(A,Y)	= $bba2		; load mflpt value from memory  in A/Y into fac1
+asmsub	FREADMEM	() clobbers(A,Y)			= $bba6		; load mflpt value from memory  in $22/$23 into fac1
+asmsub	CONUPK		(uword mflpt @ AY) clobbers(A,Y)	= $ba8c		; load mflpt value from memory  in A/Y into fac2
+asmsub	FAREADMEM	() clobbers(A,Y)			= $ba90		; load mflpt value from memory  in $22/$23 into fac2
+asmsub	MOVFA		() clobbers(A,X)			= $bbfc		; copy fac2 to fac1
+asmsub	MOVAF		() clobbers(A,X)			= $bc0c		; copy fac1 to fac2  (rounded)
+asmsub	MOVEF		() clobbers(A,X)			= $bc0f		; copy fac1 to fac2
+asmsub	MOVMF		(uword mflpt @ XY) clobbers(A,Y)	= $bbd4		; store fac1 to memory  X/Y as 5-byte mflpt
 
 ; fac1-> signed word in Y/A (might throw ILLEGAL QUANTITY)
 ; (tip: use c64flt.FTOSWRDAY to get A/Y output; lo/hi switched to normal little endian order)
-asmsub	FTOSWORDYA	() -> clobbers(X) -> (ubyte @ Y, ubyte @ A)	= $b1aa
+asmsub	FTOSWORDYA	() clobbers(X) -> ubyte @ Y, ubyte @ A  = $b1aa     ; note: calls AYINT.
 
 ; fac1 -> unsigned word in Y/A (might throw ILLEGAL QUANTITY) (result also in $14/15)
 ; (tip: use c64flt.GETADRAY to get A/Y output; lo/hi switched to normal little endian order)
-asmsub	GETADR		() -> clobbers(X) -> (ubyte @ Y, ubyte @ A)	= $b7f7
+asmsub	GETADR		() clobbers(X) -> ubyte @ Y, ubyte @ A  = $b7f7
 
-asmsub	QINT		() -> clobbers(A,X,Y) -> ()			= $bc9b		; fac1 -> 4-byte signed integer in 98-101 ($62-$65), with the MSB FIRST.
-asmsub	AYINT		() -> clobbers(A,X,Y) -> ()			= $b1bf		; fac1-> signed word in 100-101 ($64-$65) MSB FIRST. (might throw ILLEGAL QUANTITY)
+asmsub	QINT		() clobbers(A,X,Y)			= $bc9b		; fac1 -> 4-byte signed integer in 98-101 ($62-$65), with the MSB FIRST.
+asmsub	AYINT		() clobbers(A,X,Y)			= $b1bf		; fac1-> signed word in 100-101 ($64-$65) MSB FIRST. (might throw ILLEGAL QUANTITY)
 
 ; GIVAYF: signed word in Y/A (note different lsb/msb order) -> float in fac1
 ; (tip: use c64flt.GIVAYFAY to use A/Y input; lo/hi switched to normal order)
@@ -67,50 +67,50 @@ asmsub	AYINT		() -> clobbers(A,X,Y) -> ()			= $b1bf		; fac1-> signed word in 100
 ; there is also c64flt.FREADS32  that reads from 98-101 ($62-$65) MSB FIRST
 ; there is also c64flt.FREADUS32  that reads from 98-101 ($62-$65) MSB FIRST
 ; there is also c64flt.FREADS24AXY  that reads signed int24 into fac1 from A/X/Y (lo/mid/hi bytes)
-asmsub	GIVAYF		(ubyte lo @ Y, ubyte hi @ A) -> clobbers(A,X,Y) -> ()	= $b391
+asmsub	GIVAYF		(ubyte lo @ Y, ubyte hi @ A) clobbers(A,X,Y)	= $b391
 
-asmsub	FREADUY		(ubyte value @ Y) -> clobbers(A,X,Y) -> ()	= $b3a2		; 8 bit unsigned Y -> float in fac1
-asmsub	FREADSA		(byte value @ A) -> clobbers(A,X,Y) -> ()	= $bc3c		; 8 bit signed A -> float in fac1
-asmsub	FREADSTR	(ubyte length @ A) -> clobbers(A,X,Y) -> ()	= $b7b5		; str -> fac1, $22/23 must point to string, A=string length
-asmsub	FPRINTLN	() -> clobbers(A,X,Y) -> ()			= $aabc		; print string of fac1, on one line (= with newline) destroys fac1.  (consider FOUT + STROUT as well)
-asmsub	FOUT		() -> clobbers(X) -> (uword @ AY)		= $bddd		; fac1 -> string, address returned in AY ($0100)
+asmsub	FREADUY		(ubyte value @ Y) clobbers(A,X,Y)	= $b3a2		; 8 bit unsigned Y -> float in fac1
+asmsub	FREADSA		(byte value @ A) clobbers(A,X,Y)	= $bc3c		; 8 bit signed A -> float in fac1
+asmsub	FREADSTR	(ubyte length @ A) clobbers(A,X,Y)	= $b7b5		; str -> fac1, $22/23 must point to string, A=string length
+asmsub	FPRINTLN	() clobbers(A,X,Y)			= $aabc		; print string of fac1, on one line (= with newline) destroys fac1.  (consider FOUT + STROUT as well)
+asmsub	FOUT		() clobbers(X) -> uword @ AY		= $bddd		; fac1 -> string, address returned in AY ($0100)
 
-asmsub	FADDH		() -> clobbers(A,X,Y) -> ()			= $b849		; fac1 += 0.5, for rounding- call this before INT
-asmsub	MUL10		() -> clobbers(A,X,Y) -> ()			= $bae2		; fac1 *= 10
-asmsub	DIV10		() -> clobbers(A,X,Y) -> ()			= $bafe		; fac1 /= 10 , CAUTION: result is always positive!
-asmsub	FCOMP		(uword mflpt @ AY) -> clobbers(X,Y) -> (ubyte @ A) = $bc5b		; A = compare fac1 to mflpt in A/Y, 0=equal 1=fac1 is greater, 255=fac1 is less than
+asmsub	FADDH		() clobbers(A,X,Y)			= $b849		; fac1 += 0.5, for rounding- call this before INT
+asmsub	MUL10		() clobbers(A,X,Y)			= $bae2		; fac1 *= 10
+asmsub	DIV10		() clobbers(A,X,Y)			= $bafe		; fac1 /= 10 , CAUTION: result is always positive!
+asmsub	FCOMP		(uword mflpt @ AY) clobbers(X,Y) -> ubyte @ A = $bc5b		; A = compare fac1 to mflpt in A/Y, 0=equal 1=fac1 is greater, 255=fac1 is less than
 
-asmsub	FADDT		() -> clobbers(A,X,Y) -> ()			= $b86a		; fac1 += fac2
-asmsub	FADD		(uword mflpt @ AY) -> clobbers(A,X,Y) -> ()	= $b867		; fac1 += mflpt value from A/Y
-asmsub	FSUBT		() -> clobbers(A,X,Y) -> ()			= $b853		; fac1 = fac2-fac1   mind the order of the operands
-asmsub	FSUB		(uword mflpt @ AY) -> clobbers(A,X,Y) -> ()	= $b850		; fac1 = mflpt from A/Y - fac1
-asmsub	FMULTT 		() -> clobbers(A,X,Y) -> ()			= $ba2b		; fac1 *= fac2
-asmsub	FMULT		(uword mflpt @ AY) -> clobbers(A,X,Y) -> ()	= $ba28		; fac1 *= mflpt value from A/Y
-asmsub	FDIVT 		() -> clobbers(A,X,Y) -> ()			= $bb12		; fac1 = fac2/fac1  (remainder in fac2)  mind the order of the operands
-asmsub	FDIV  		(uword mflpt @ AY) -> clobbers(A,X,Y) -> ()	= $bb0f		; fac1 = mflpt in A/Y / fac1  (remainder in fac2)
-asmsub	FPWRT		() -> clobbers(A,X,Y) -> ()			= $bf7b		; fac1 = fac2 ** fac1
-asmsub	FPWR		(uword mflpt @ AY) -> clobbers(A,X,Y) -> ()	= $bf78		; fac1 = fac2 ** mflpt from A/Y
+asmsub	FADDT		() clobbers(A,X,Y)			= $b86a		; fac1 += fac2
+asmsub	FADD		(uword mflpt @ AY) clobbers(A,X,Y)	= $b867		; fac1 += mflpt value from A/Y
+asmsub	FSUBT		() clobbers(A,X,Y)			= $b853		; fac1 = fac2-fac1   mind the order of the operands
+asmsub	FSUB		(uword mflpt @ AY) clobbers(A,X,Y)	= $b850		; fac1 = mflpt from A/Y - fac1
+asmsub	FMULTT 		() clobbers(A,X,Y)			= $ba2b		; fac1 *= fac2
+asmsub	FMULT		(uword mflpt @ AY) clobbers(A,X,Y)	= $ba28		; fac1 *= mflpt value from A/Y
+asmsub	FDIVT 		() clobbers(A,X,Y)			= $bb12		; fac1 = fac2/fac1  (remainder in fac2)  mind the order of the operands
+asmsub	FDIV  		(uword mflpt @ AY) clobbers(A,X,Y)	= $bb0f		; fac1 = mflpt in A/Y / fac1  (remainder in fac2)
+asmsub	FPWRT		() clobbers(A,X,Y)			= $bf7b		; fac1 = fac2 ** fac1
+asmsub	FPWR		(uword mflpt @ AY) clobbers(A,X,Y)	= $bf78		; fac1 = fac2 ** mflpt from A/Y
 
-asmsub	NOTOP		() -> clobbers(A,X,Y) -> ()			= $aed4		; fac1 = NOT(fac1)
-asmsub	INT		() -> clobbers(A,X,Y) -> ()			= $bccc		; INT() truncates, use FADDH first to round instead of trunc
-asmsub	LOG		() -> clobbers(A,X,Y) -> ()			= $b9ea		; fac1 = LN(fac1)  (natural log)
-asmsub	SGN		() -> clobbers(A,X,Y) -> ()			= $bc39		; fac1 = SGN(fac1), result of SIGN (-1, 0 or 1)
-asmsub	SIGN		() -> clobbers() -> (ubyte @ A)			= $bc2b		; SIGN(fac1) to A, $ff, $0, $1 for negative, zero, positive
-asmsub	ABS		() -> clobbers() -> ()				= $bc58		; fac1 = ABS(fac1)
-asmsub	SQR		() -> clobbers(A,X,Y) -> ()			= $bf71		; fac1 = SQRT(fac1)
-asmsub	SQRA		() -> clobbers(A,X,Y) -> ()			= $bf74		; fac1 = SQRT(fac2)
-asmsub	EXP		() -> clobbers(A,X,Y) -> ()			= $bfed		; fac1 = EXP(fac1)  (e ** fac1)
-asmsub	NEGOP		() -> clobbers(A) -> ()				= $bfb4		; switch the sign of fac1
-asmsub	RND		() -> clobbers(A,X,Y) -> ()			= $e097		; fac1 = RND(fac1) float random number generator
-asmsub	COS		() -> clobbers(A,X,Y) -> ()			= $e264		; fac1 = COS(fac1)
-asmsub	SIN		() -> clobbers(A,X,Y) -> ()			= $e26b		; fac1 = SIN(fac1)
-asmsub	TAN		() -> clobbers(A,X,Y) -> ()			= $e2b4		; fac1 = TAN(fac1)
-asmsub	ATN		() -> clobbers(A,X,Y) -> ()			= $e30e		; fac1 = ATN(fac1)
+asmsub	NOTOP		() clobbers(A,X,Y)			= $aed4		; fac1 = NOT(fac1)
+asmsub	INT		() clobbers(A,X,Y)			= $bccc		; INT() truncates, use FADDH first to round instead of trunc
+asmsub	LOG		() clobbers(A,X,Y)			= $b9ea		; fac1 = LN(fac1)  (natural log)
+asmsub	SGN		() clobbers(A,X,Y)			= $bc39		; fac1 = SGN(fac1), result of SIGN (-1, 0 or 1)
+asmsub	SIGN		() -> ubyte @ A				= $bc2b		; SIGN(fac1) to A, $ff, $0, $1 for negative, zero, positive
+asmsub	ABS		()					= $bc58		; fac1 = ABS(fac1)
+asmsub	SQR		() clobbers(A,X,Y)			= $bf71		; fac1 = SQRT(fac1)
+asmsub	SQRA		() clobbers(A,X,Y)			= $bf74		; fac1 = SQRT(fac2)
+asmsub	EXP		() clobbers(A,X,Y)			= $bfed		; fac1 = EXP(fac1)  (e ** fac1)
+asmsub	NEGOP		() clobbers(A)				= $bfb4		; switch the sign of fac1
+asmsub	RND		() clobbers(A,X,Y)			= $e097		; fac1 = RND(fac1) float random number generator
+asmsub	COS		() clobbers(A,X,Y)			= $e264		; fac1 = COS(fac1)
+asmsub	SIN		() clobbers(A,X,Y)			= $e26b		; fac1 = SIN(fac1)
+asmsub	TAN		() clobbers(A,X,Y)			= $e2b4		; fac1 = TAN(fac1)
+asmsub	ATN		() clobbers(A,X,Y)			= $e30e		; fac1 = ATN(fac1)
 
 
 
 
-asmsub  FREADS32  () -> clobbers(A,X,Y) -> ()  {
+asmsub  FREADS32  () clobbers(A,X,Y)  {
 	; ---- fac1 = signed int32 from $62-$65 big endian (MSB FIRST)
 	%asm {{
 		lda  $62
@@ -122,7 +122,7 @@ asmsub  FREADS32  () -> clobbers(A,X,Y) -> ()  {
 	}}
 }
 
-asmsub  FREADUS32  () -> clobbers(A,X,Y) -> ()  {
+asmsub  FREADUS32  () clobbers(A,X,Y)  {
 	; ---- fac1 = uint32 from $62-$65 big endian (MSB FIRST)
 	%asm {{
 		sec
@@ -132,7 +132,7 @@ asmsub  FREADUS32  () -> clobbers(A,X,Y) -> ()  {
 	}}
 }
 
-asmsub  FREADS24AXY  (ubyte lo @ A, ubyte mid @ X, ubyte hi @ Y) -> clobbers(A,X,Y) -> ()  {
+asmsub  FREADS24AXY  (ubyte lo @ A, ubyte mid @ X, ubyte hi @ Y) clobbers(A,X,Y)  {
 	; ---- fac1 = signed int24 (A/X/Y contain lo/mid/hi bytes)
 	;      note: there is no FREADU24AXY (unsigned), use FREADUS32 instead.
 	%asm {{
@@ -149,7 +149,7 @@ asmsub  FREADS24AXY  (ubyte lo @ A, ubyte mid @ X, ubyte hi @ Y) -> clobbers(A,X
 	}}
 }
 
-asmsub  GIVUAYFAY  (uword value @ AY) -> clobbers(A,X,Y) -> ()  {
+asmsub  GIVUAYFAY  (uword value @ AY) clobbers(A,X,Y)  {
 	; ---- unsigned 16 bit word in A/Y (lo/hi) to fac1
 	%asm {{
 		sty  $62
@@ -160,7 +160,7 @@ asmsub  GIVUAYFAY  (uword value @ AY) -> clobbers(A,X,Y) -> ()  {
 	}}
 }
 
-asmsub  GIVAYFAY  (uword value @ AY) -> clobbers(A,X,Y) -> ()  {
+asmsub  GIVAYFAY  (uword value @ AY) clobbers(A,X,Y)  {
 	; ---- signed 16 bit word in A/Y (lo/hi) to float in fac1
 	%asm {{
 		sta  c64.SCRATCH_ZPREG
@@ -170,7 +170,7 @@ asmsub  GIVAYFAY  (uword value @ AY) -> clobbers(A,X,Y) -> ()  {
 	}}
 }
 
-asmsub  FTOSWRDAY  () -> clobbers(X) -> (uword @ AY)  {
+asmsub  FTOSWRDAY  () clobbers(X) -> uword @ AY  {
 	; ---- fac1 to signed word in A/Y
 	%asm {{
 		jsr  FTOSWORDYA	; note the inverse Y/A order
@@ -181,7 +181,7 @@ asmsub  FTOSWRDAY  () -> clobbers(X) -> (uword @ AY)  {
 	}}
 }
 
-asmsub  GETADRAY  () -> clobbers(X) -> (uword @ AY)  {
+asmsub  GETADRAY  () clobbers(X) -> uword @ AY  {
 	; ---- fac1 to unsigned word in A/Y
 	%asm {{
 		jsr  GETADR		; this uses the inverse order, Y/A
@@ -196,8 +196,8 @@ sub  print_f  (float value) {
 	; ---- prints the floating point value (without a newline) using basic rom routines.
 	%asm {{
 		stx  c64.SCRATCH_ZPREGX
-		lda  #<print_f_value
-		ldy  #>print_f_value
+		lda  #<value
+		ldy  #>value
 		jsr  MOVFM		; load float into fac1
 		jsr  FOUT		; fac1 to string in A/Y
 		jsr  c64.STROUT			; print string in A/Y
@@ -310,7 +310,7 @@ stack_uw2float	.proc
 		jmp  push_fac1_as_result
 		.pend
 
-stack_float2w	.proc
+stack_float2w	.proc               ; also used for float2b
 		jsr  pop_float_fac1
 		stx  c64.SCRATCH_ZPREGX
 		jsr  AYINT
@@ -323,7 +323,7 @@ stack_float2w	.proc
 		rts
 		.pend
 
-stack_float2uw	.proc
+stack_float2uw	.proc               ; also used for float2ub
 		jsr  pop_float_fac1
 		stx  c64.SCRATCH_ZPREGX
 		jsr  GETADR
@@ -954,6 +954,16 @@ func_sum_f	.proc
 		bne  -
 +		jmp  push_fac1_as_result
 		.pend
+		
+sign_f		.proc
+		jsr  pop_float_fac1
+		jsr  SIGN
+		sta  c64.ESTACK_LO,x
+		dex
+		rts
+		.pend
+		
+
 }}
 
 }  ; ------ end of block c64flt

compiler/res/prog8lib/c64lib.p8

@@ -6,7 +6,7 @@
 ; indent format: TABS, size=8
 
 
-~ c64 {
+c64 {
 		const   uword  ESTACK_LO	= $ce00		; evaluation stack (lsb)
 		const   uword  ESTACK_HI	= $cf00		; evaluation stack (msb)
 		&ubyte  SCRATCH_ZPB1		= $02		; scratch byte 1 in ZP
@@ -21,7 +21,7 @@
 		&ubyte  TIME_LO			= $a2		;    .. lo byte. Updated by IRQ every 1/60 sec
 		&ubyte  STKEY			= $91		; various keyboard statuses (updated by IRQ)
 		&ubyte  SFDX			= $cb		; current key pressed (matrix value) (updated by IRQ)
-	
+
 		&ubyte  COLOR			= $0286		; cursor color
 		&ubyte  HIBASE			= $0288		; screen base address / 256 (hi-byte of screen memory address)
 		&uword  CINV			= $0314		; IRQ vector
@@ -63,8 +63,8 @@
 		&ubyte  SP6Y		= $d00d
 		&ubyte  SP7X		= $d00e
 		&ubyte  SP7Y		= $d00f
-		&ubyte[16]  SPXY		= $d000		; the 8 sprite X and Y registers as an array.
-		&uword[8]  SPXYW		= $d000		; the 8 sprite X and Y registers as a combined xy word array.
+		&ubyte[16]  SPXY	= $d000		; the 8 sprite X and Y registers as an array.
+		&uword[8]  SPXYW	= $d000		; the 8 sprite X and Y registers as a combined xy word array.
 
 		&ubyte  MSIGX		= $d010
 		&ubyte  SCROLY		= $d011
@@ -76,7 +76,7 @@
 		&ubyte  YXPAND		= $d017
 		&ubyte  VMCSB		= $d018
 		&ubyte  VICIRQ		= $d019
-		&ubyte  IREQMASK		= $d01a
+		&ubyte  IREQMASK	= $d01a
 		&ubyte  SPBGPR		= $d01b
 		&ubyte  SPMC		= $d01c
 		&ubyte  XXPAND		= $d01d
@@ -98,7 +98,7 @@
 		&ubyte  SP5COL		= $d02c
 		&ubyte  SP6COL		= $d02d
 		&ubyte  SP7COL		= $d02e
-		&ubyte[8]  SPCOL		= $d027
+		&ubyte[8]  SPCOL	= $d027
 
 
 ; ---- end of VIC-II registers ----
@@ -107,8 +107,8 @@
 
 		&ubyte  CIA1PRA		= $DC00		; CIA 1 DRA, keyboard column drive (and joystick control port #2)
 		&ubyte  CIA1PRB		= $DC01		; CIA 1 DRB, keyboard row port (and joystick control port #1)
-		&ubyte  CIA1DDRA		= $DC02		; CIA 1 DDRA, keyboard column
-		&ubyte  CIA1DDRB		= $DC03		; CIA 1 DDRB, keyboard row
+		&ubyte  CIA1DDRA	= $DC02		; CIA 1 DDRA, keyboard column
+		&ubyte  CIA1DDRB	= $DC03		; CIA 1 DDRB, keyboard row
 		&ubyte  CIA1TAL		= $DC04		; CIA 1 timer A low byte
 		&ubyte  CIA1TAH		= $DC05		; CIA 1 timer A high byte
 		&ubyte  CIA1TBL		= $DC06		; CIA 1 timer B low byte
@@ -124,8 +124,8 @@
 
 		&ubyte  CIA2PRA		= $DD00		; CIA 2 DRA, serial port and video address
 		&ubyte  CIA2PRB		= $DD01		; CIA 2 DRB, RS232 port / USERPORT
-		&ubyte  CIA2DDRA		= $DD02		; CIA 2 DDRA, serial port and video address
-		&ubyte  CIA2DDRB		= $DD03		; CIA 2 DDRB, RS232 port / USERPORT
+		&ubyte  CIA2DDRA	= $DD02		; CIA 2 DDRA, serial port and video address
+		&ubyte  CIA2DDRB	= $DD03		; CIA 2 DDRB, RS232 port / USERPORT
 		&ubyte  CIA2TAL		= $DD04		; CIA 2 timer A low byte
 		&ubyte  CIA2TAH		= $DD05		; CIA 2 timer A high byte
 		&ubyte  CIA2TBL		= $DD06		; CIA 2 timer B low byte
@@ -186,8 +186,8 @@
 
 ; ---- C64 basic routines ----
 
-asmsub	CLEARSCR	() -> clobbers(A,X,Y) -> ()		= $E544		; clear the screen
-asmsub	HOMECRSR	() -> clobbers(A,X,Y) -> ()		= $E566		; cursor to top left of screen
+asmsub	CLEARSCR	() clobbers(A,X,Y)		= $E544		; clear the screen
+asmsub	HOMECRSR	() clobbers(A,X,Y)		= $E566		; cursor to top left of screen
 
 
 ; ---- end of C64 basic routines ----
@@ -195,48 +195,48 @@ asmsub	HOMECRSR	() -> clobbers(A,X,Y) -> ()		= $E566		; cursor to top left of sc
 
 ; ---- C64 kernal routines ----
 
-asmsub	STROUT   (uword strptr @ AY) -> clobbers(A, X, Y) -> ()	= $AB1E		; print null-terminated string (use c64scr.print instead)
-asmsub	IRQDFRT  () -> clobbers(A,X,Y) -> ()			= $EA31		; default IRQ routine
-asmsub	IRQDFEND () -> clobbers(A,X,Y) -> ()			= $EA81		; default IRQ end/cleanup
-asmsub	CINT     () -> clobbers(A,X,Y) -> ()			= $FF81		; (alias: SCINIT) initialize screen editor and video chip
-asmsub	IOINIT   () -> clobbers(A, X) -> ()			= $FF84		; initialize I/O devices (CIA, SID, IRQ)
-asmsub	RAMTAS   () -> clobbers(A,X,Y) -> ()			= $FF87		; initialize RAM, tape buffer, screen
-asmsub	RESTOR   () -> clobbers(A,X,Y) -> ()			= $FF8A		; restore default I/O vectors
-asmsub	VECTOR   (ubyte dir @ Pc, uword userptr @ XY) -> clobbers(A,Y) -> ()	= $FF8D		; read/set I/O vector table
-asmsub	SETMSG   (ubyte value @ A) -> clobbers() -> ()		= $FF90		; set Kernal message control flag
-asmsub	SECOND   (ubyte address @ A) -> clobbers(A) -> ()	= $FF93		; (alias: LSTNSA) send secondary address after LISTEN
-asmsub	TKSA     (ubyte address @ A) -> clobbers(A) -> ()	= $FF96		; (alias: TALKSA) send secondary address after TALK
-asmsub	MEMTOP   (ubyte dir @ Pc, uword address @ XY) -> clobbers() -> (uword @ XY)	= $FF99		; read/set top of memory  pointer
-asmsub	MEMBOT   (ubyte dir @ Pc, uword address @ XY) -> clobbers() -> (uword @ XY)	= $FF9C		; read/set bottom of memory  pointer
-asmsub	SCNKEY   () -> clobbers(A,X,Y) -> ()			= $FF9F		; scan the keyboard
-asmsub	SETTMO   (ubyte timeout @ A) -> clobbers() -> ()	= $FFA2		; set time-out flag for IEEE bus
-asmsub	ACPTR    () -> clobbers() -> (ubyte @ A)			= $FFA5		; (alias: IECIN) input byte from serial bus
-asmsub	CIOUT    (ubyte databyte @ A) -> clobbers() -> ()	= $FFA8		; (alias: IECOUT) output byte to serial bus
-asmsub	UNTLK    () -> clobbers(A) -> ()			= $FFAB		; command serial bus device to UNTALK
-asmsub	UNLSN    () -> clobbers(A) -> ()			= $FFAE		; command serial bus device to UNLISTEN
-asmsub	LISTEN   (ubyte device @ A) -> clobbers(A) -> ()	= $FFB1		; command serial bus device to LISTEN
-asmsub	TALK     (ubyte device @ A) -> clobbers(A) -> ()	= $FFB4		; command serial bus device to TALK
-asmsub	READST   () -> clobbers() -> (ubyte @ A)			= $FFB7		; read I/O status word
-asmsub	SETLFS   (ubyte logical @ A, ubyte device @ X, ubyte address @ Y) -> clobbers() -> () = $FFBA	; set logical file parameters
-asmsub	SETNAM   (ubyte namelen @ A, str filename @ XY) -> clobbers() -> ()	= $FFBD		; set filename parameters
-asmsub	OPEN     () -> clobbers(A,X,Y) -> ()			= $FFC0		; (via 794 ($31A)) open a logical file
-asmsub	CLOSE    (ubyte logical @ A) -> clobbers(A,X,Y) -> ()	= $FFC3		; (via 796 ($31C)) close a logical file
-asmsub	CHKIN    (ubyte logical @ X) -> clobbers(A,X) -> ()	= $FFC6		; (via 798 ($31E)) define an input channel
-asmsub	CHKOUT   (ubyte logical @ X) -> clobbers(A,X) -> ()	= $FFC9		; (via 800 ($320)) define an output channel
-asmsub	CLRCHN   () -> clobbers(A,X) -> ()			= $FFCC		; (via 802 ($322)) restore default devices
-asmsub	CHRIN    () -> clobbers(Y) -> (ubyte @ A)		= $FFCF		; (via 804 ($324)) input a character (for keyboard, read a whole line from the screen) A=byte read.
-asmsub	CHROUT   (ubyte char @ A) -> clobbers() -> ()		= $FFD2		; (via 806 ($326)) output a character
-asmsub	LOAD     (ubyte verify @ A, uword address @ XY) -> clobbers() -> (ubyte @Pc, ubyte @ A, ubyte @ X, ubyte @ Y) = $FFD5	; (via 816 ($330)) load from device
-asmsub	SAVE     (ubyte zp_startaddr @ A, uword endaddr @ XY) -> clobbers() -> (ubyte @ Pc, ubyte @ A) = $FFD8	; (via 818 ($332)) save to a device
-asmsub	SETTIM   (ubyte low @ A, ubyte middle @ X, ubyte high @ Y) -> clobbers() -> ()	= $FFDB		; set the software clock
-asmsub	RDTIM    () -> clobbers() -> (ubyte @ A, ubyte @ X, ubyte @ Y) = $FFDE	; read the software clock
-asmsub	STOP     () -> clobbers(A,X) -> (ubyte @ Pz, ubyte @ Pc)	= $FFE1		; (via 808 ($328)) check the STOP key
-asmsub	GETIN    () -> clobbers(X,Y) -> (ubyte @ A)		= $FFE4		; (via 810 ($32A)) get a character
-asmsub	CLALL    () -> clobbers(A,X) -> ()			= $FFE7		; (via 812 ($32C)) close all files
-asmsub	UDTIM    () -> clobbers(A,X) -> ()			= $FFEA		; update the software clock
-asmsub	SCREEN   () -> clobbers() -> (ubyte @ X, ubyte @ Y)	= $FFED		; read number of screen rows and columns
-asmsub	PLOT     (ubyte dir @ Pc, ubyte col @ Y, ubyte row @ X) -> clobbers() -> (ubyte @ X, ubyte @ Y)	= $FFF0		; read/set position of cursor on screen.  Use c64scr.plot for a 'safe' wrapper that preserves X.
-asmsub	IOBASE   () -> clobbers() -> (uword @ XY)		= $FFF3		; read base address of I/O devices
+asmsub	STROUT   (uword strptr @ AY) clobbers(A, X, Y)	= $AB1E		; print null-terminated string (use c64scr.print instead)
+asmsub	IRQDFRT  () clobbers(A,X,Y)			= $EA31		; default IRQ routine
+asmsub	IRQDFEND () clobbers(A,X,Y)			= $EA81		; default IRQ end/cleanup
+asmsub	CINT     () clobbers(A,X,Y)			= $FF81		; (alias: SCINIT) initialize screen editor and video chip
+asmsub	IOINIT   () clobbers(A, X)			= $FF84		; initialize I/O devices (CIA, SID, IRQ)
+asmsub	RAMTAS   () clobbers(A,X,Y)			= $FF87		; initialize RAM, tape buffer, screen
+asmsub	RESTOR   () clobbers(A,X,Y)			= $FF8A		; restore default I/O vectors
+asmsub	VECTOR   (uword userptr @ XY, ubyte dir @ Pc) clobbers(A,Y)  = $FF8D		; read/set I/O vector table
+asmsub	SETMSG   (ubyte value @ A)			= $FF90		; set Kernal message control flag
+asmsub	SECOND   (ubyte address @ A) clobbers(A)	= $FF93		; (alias: LSTNSA) send secondary address after LISTEN
+asmsub	TKSA     (ubyte address @ A) clobbers(A)	= $FF96		; (alias: TALKSA) send secondary address after TALK
+asmsub	MEMTOP   (uword address @ XY, ubyte dir @ Pc) -> uword @ XY	= $FF99		; read/set top of memory  pointer
+asmsub	MEMBOT   (uword address @ XY, ubyte dir @ Pc) -> uword @ XY	= $FF9C		; read/set bottom of memory  pointer
+asmsub	SCNKEY   () clobbers(A,X,Y)			= $FF9F		; scan the keyboard
+asmsub	SETTMO   (ubyte timeout @ A)			= $FFA2		; set time-out flag for IEEE bus
+asmsub	ACPTR    () -> ubyte @ A			= $FFA5		; (alias: IECIN) input byte from serial bus
+asmsub	CIOUT    (ubyte databyte @ A)			= $FFA8		; (alias: IECOUT) output byte to serial bus
+asmsub	UNTLK    () clobbers(A)				= $FFAB		; command serial bus device to UNTALK
+asmsub	UNLSN    () clobbers(A)				= $FFAE		; command serial bus device to UNLISTEN
+asmsub	LISTEN   (ubyte device @ A) clobbers(A)		= $FFB1		; command serial bus device to LISTEN
+asmsub	TALK     (ubyte device @ A) clobbers(A)		= $FFB4		; command serial bus device to TALK
+asmsub	READST   () -> ubyte @ A			= $FFB7		; read I/O status word
+asmsub	SETLFS   (ubyte logical @ A, ubyte device @ X, ubyte address @ Y) = $FFBA	; set logical file parameters
+asmsub	SETNAM   (ubyte namelen @ A, str filename @ XY)	= $FFBD		; set filename parameters
+asmsub	OPEN     () clobbers(A,X,Y)			= $FFC0		; (via 794 ($31A)) open a logical file
+asmsub	CLOSE    (ubyte logical @ A) clobbers(A,X,Y)	= $FFC3		; (via 796 ($31C)) close a logical file
+asmsub	CHKIN    (ubyte logical @ X) clobbers(A,X)	= $FFC6		; (via 798 ($31E)) define an input channel
+asmsub	CHKOUT   (ubyte logical @ X) clobbers(A,X)	= $FFC9		; (via 800 ($320)) define an output channel
+asmsub	CLRCHN   () clobbers(A,X)			= $FFCC		; (via 802 ($322)) restore default devices
+asmsub	CHRIN    () clobbers(Y) -> ubyte @ A		= $FFCF		; (via 804 ($324)) input a character (for keyboard, read a whole line from the screen) A=byte read.
+asmsub	CHROUT   (ubyte char @ A)			= $FFD2		; (via 806 ($326)) output a character
+asmsub	LOAD     (ubyte verify @ A, uword address @ XY) -> ubyte @Pc, ubyte @ A, ubyte @ X, ubyte @ Y = $FFD5	; (via 816 ($330)) load from device
+asmsub	SAVE     (ubyte zp_startaddr @ A, uword endaddr @ XY) -> ubyte @ Pc, ubyte @ A = $FFD8	; (via 818 ($332)) save to a device
+asmsub	SETTIM   (ubyte low @ A, ubyte middle @ X, ubyte high @ Y)	= $FFDB		; set the software clock
+asmsub	RDTIM    () -> ubyte @ A, ubyte @ X, ubyte @ Y	= $FFDE	; read the software clock
+asmsub	STOP     () clobbers(A,X) -> ubyte @ Pz, ubyte @ Pc	= $FFE1		; (via 808 ($328)) check the STOP key
+asmsub	GETIN    () clobbers(X,Y) -> ubyte @ A		= $FFE4		; (via 810 ($32A)) get a character
+asmsub	CLALL    () clobbers(A,X)			= $FFE7		; (via 812 ($32C)) close all files
+asmsub	UDTIM    () clobbers(A,X)			= $FFEA		; update the software clock
+asmsub	SCREEN   () -> ubyte @ X, ubyte @ Y		= $FFED		; read number of screen rows and columns
+asmsub	PLOT     (ubyte col @ Y, ubyte row @ X, ubyte dir @ Pc) -> ubyte @ X, ubyte @ Y	= $FFF0		; read/set position of cursor on screen.  Use c64scr.plot for a 'safe' wrapper that preserves X.
+asmsub	IOBASE   () -> uword @ XY			= $FFF3		; read base address of I/O devices
 
 ; ---- end of C64 kernal routines ----
 

compiler/res/prog8lib/c64utils.p8

@@ -9,34 +9,205 @@
 %import c64lib
 
 
-~ c64utils {
+c64utils {
 
 		const   uword  ESTACK_LO	= $ce00
 		const   uword  ESTACK_HI	= $cf00
 
 
-; ----- utility functions ----
+; ----- number conversions to decimal strings
 
-asmsub  ubyte2decimal  (ubyte value @ A) -> clobbers() -> (ubyte @ Y, ubyte @ X, ubyte @ A)  {
-	; ---- A to decimal string in Y/X/A  (100s in Y, 10s in X, 1s in A)
-	%asm {{
-		ldy  #$2f
-		ldx  #$3a
-		sec
--               iny
-		sbc  #100
-		bcs  -
--               dex
-		adc  #10
-		bmi  -
-		adc  #$2f
-		rts
+asmsub  ubyte2decimal  (ubyte value @ A) -> ubyte @ Y, ubyte @ A, ubyte @ X  {
+	; ---- A to decimal string in Y/A/X  (100s in Y, 10s in A, 1s in X)
+    %asm {{
+        ldy  #uword2decimal.ASCII_0_OFFSET
+        bne  uword2decimal.hex_try200
+        rts
 	}}
 }
 
-asmsub  byte2decimal  (ubyte value @ A) -> clobbers() -> (ubyte @ Y, ubyte @ X, ubyte @ A)  {
-	; ---- A (signed byte) to decimal string in Y/X/A  (100s in Y, 10s in X, 1s in A)
-	;      note: the '-' is not part of the conversion here if it's a negative number
+asmsub  uword2decimal  (uword value @ AY) -> ubyte @Y, ubyte @A, ubyte @X  {
+    ;  ---- convert 16 bit uword in A/Y to decimal
+    ;  output in uword2decimal.decTenThousands, decThousands, decHundreds, decTens, decOnes
+    ;  (these are terminated by a zero byte so they can be easily printed)
+    ;  also returns Y = 100's, A = 10's, X = 1's
+
+    %asm {{
+
+;Convert 16 bit Hex to Decimal (0-65535) Rev 2
+;By Omegamatrix    Further optimizations by tepples
+; routine from http://forums.nesdev.com/viewtopic.php?f=2&t=11341&start=15
+
+;HexToDec99
+; start in A
+; end with A = 10's, decOnes (also in X)
+
+;HexToDec255
+; start in A
+; end with Y = 100's, A = 10's, decOnes (also in X)
+
+;HexToDec999
+; start with A = high byte, Y = low byte
+; end with Y = 100's, A = 10's, decOnes (also in X)
+; requires 1 extra temp register on top of decOnes, could combine
+; these two if HexToDec65535 was eliminated...
+
+;HexToDec65535
+; start with A/Y (low/high) as 16 bit value
+; end with decTenThousand, decThousand, Y = 100's, A = 10's, decOnes (also in X)
+; (irmen: I store Y and A in decHundreds and decTens too, so all of it can be easily printed)
+
+
+ASCII_0_OFFSET 	= $30
+temp       	    = c64.SCRATCH_ZPB1	; byte in zeropage
+hexHigh      	= c64.SCRATCH_ZPWORD1	; byte in zeropage
+hexLow       	= c64.SCRATCH_ZPWORD1+1	; byte in zeropage
+
+
+HexToDec65535; SUBROUTINE
+    sty    hexHigh               ;3  @9
+    sta    hexLow                ;3  @12
+    tya
+    tax                          ;2  @14
+    lsr    a                     ;2  @16
+    lsr    a                     ;2  @18   integer divide 1024 (result 0-63)
+
+    cpx    #$A7                  ;2  @20   account for overflow of multiplying 24 from 43,000 ($A7F8) onward,
+    adc    #1                    ;2  @22   we can just round it to $A700, and the divide by 1024 is fine...
+
+    ;at this point we have a number 1-65 that we have to times by 24,
+    ;add to original sum, and Mod 1024 to get a remainder 0-999
+
+
+    sta    temp                  ;3  @25
+    asl    a                     ;2  @27
+    adc    temp                  ;3  @30  x3
+    tay                          ;2  @32
+    lsr    a                     ;2  @34
+    lsr    a                     ;2  @36
+    lsr    a                     ;2  @38
+    lsr    a                     ;2  @40
+    lsr    a                     ;2  @42
+    tax                          ;2  @44
+    tya                          ;2  @46
+    asl    a                     ;2  @48
+    asl    a                     ;2  @50
+    asl    a                     ;2  @52
+    clc                          ;2  @54
+    adc    hexLow                ;3  @57
+    sta    hexLow                ;3  @60
+    txa                          ;2  @62
+    adc    hexHigh               ;3  @65
+    sta    hexHigh               ;3  @68
+    ror    a                     ;2  @70
+    lsr    a                     ;2  @72
+    tay                          ;2  @74    integer divide 1,000 (result 0-65)
+
+    lsr    a                     ;2  @76    split the 1,000 and 10,000 digit
+    tax                          ;2  @78
+    lda    ShiftedBcdTab,x       ;4  @82
+    tax                          ;2  @84
+    rol    a                     ;2  @86
+    and    #$0F                  ;2  @88
+    ora    #ASCII_0_OFFSET
+    sta    decThousands          ;3  @91
+    txa                          ;2  @93
+    lsr    a                     ;2  @95
+    lsr    a                     ;2  @97
+    lsr    a                     ;2  @99
+    ora    #ASCII_0_OFFSET
+    sta    decTenThousands       ;3  @102
+
+    lda    hexLow                ;3  @105
+    cpy    temp                  ;3  @108
+    bmi    _doSubtract           ;2³ @110/111
+    beq    _useZero               ;2³ @112/113
+    adc    #23 + 24              ;2  @114
+_doSubtract
+    sbc    #23                   ;2  @116
+    sta    hexLow                ;3  @119
+_useZero
+    lda    hexHigh               ;3  @122
+    sbc    #0                    ;2  @124
+
+Start100s
+    and    #$03                  ;2  @126
+    tax                          ;2  @128   0,1,2,3
+    cmp    #2                    ;2  @130
+    rol    a                     ;2  @132   0,2,5,7
+    ora    #ASCII_0_OFFSET
+    tay                          ;2  @134   Y = Hundreds digit
+
+    lda    hexLow                ;3  @137
+    adc    Mod100Tab,x           ;4  @141    adding remainder of 256, 512, and 256+512 (all mod 100)
+    bcs    hex_doSub200             ;2³ @143/144
+
+hex_try200
+    cmp    #200                  ;2  @145
+    bcc    hex_try100               ;2³ @147/148
+hex_doSub200
+    iny                          ;2  @149
+    iny                          ;2  @151
+    sbc    #200                  ;2  @153
+hex_try100
+    cmp    #100                  ;2  @155
+    bcc    HexToDec99            ;2³ @157/158
+    iny                          ;2  @159
+    sbc    #100                  ;2  @161
+
+HexToDec99; SUBROUTINE
+    lsr    a                     ;2  @163
+    tax                          ;2  @165
+    lda    ShiftedBcdTab,x       ;4  @169
+    tax                          ;2  @171
+    rol    a                     ;2  @173
+    and    #$0F                  ;2  @175
+    ora    #ASCII_0_OFFSET
+    sta    decOnes               ;3  @178
+    txa                          ;2  @180
+    lsr    a                     ;2  @182
+    lsr    a                     ;2  @184
+    lsr    a                     ;2  @186
+    ora    #ASCII_0_OFFSET
+
+    ; irmen: load X with ones, and store Y and A too, for easy printing afterwards
+    sty  decHundreds
+    sta  decTens
+    ldx  decOnes
+    rts                          ;6  @192   Y=hundreds, A = tens digit, X=ones digit
+
+
+HexToDec999; SUBROUTINE
+    sty    hexLow                ;3  @9
+    jmp    Start100s             ;3  @12
+
+Mod100Tab
+    .byte 0,56,12,56+12
+
+ShiftedBcdTab
+    .byte $00,$01,$02,$03,$04,$08,$09,$0A,$0B,$0C
+    .byte $10,$11,$12,$13,$14,$18,$19,$1A,$1B,$1C
+    .byte $20,$21,$22,$23,$24,$28,$29,$2A,$2B,$2C
+    .byte $30,$31,$32,$33,$34,$38,$39,$3A,$3B,$3C
+    .byte $40,$41,$42,$43,$44,$48,$49,$4A,$4B,$4C
+
+decTenThousands   	.byte  0
+decThousands    	.byte  0
+decHundreds		.byte  0
+decTens			.byte  0
+decOnes   		.byte  0
+			.byte  0		; zero-terminate the decimal output string
+
+    }}
+}
+
+
+; ----- utility functions ----
+
+
+asmsub  byte2decimal  (byte value @ A) -> ubyte @ Y, ubyte @ A, ubyte @ X  {
+	; ---- A (signed byte) to decimal string in Y/A/X  (100s in Y, 10s in A, 1s in X)
+	;      note: if the number is negative, you have to deal with the '-' yourself!
 	%asm {{
 		cmp  #0
 		bpl  +
@@ -47,8 +218,8 @@ asmsub  byte2decimal  (ubyte value @ A) -> clobbers() -> (ubyte @ Y, ubyte @ X,
 	}}
 }
 
-asmsub  ubyte2hex  (ubyte value @ A) -> clobbers() -> (ubyte @ A, ubyte @ Y)  {
-	; ---- A to hex string in AY (first hex char in A, second hex char in Y)
+asmsub  ubyte2hex  (ubyte value @ A) -> ubyte @ A, ubyte @ Y  {
+	; ---- A to hex petscii string in AY (first hex char in A, second hex char in Y)
 	%asm {{
 		stx  c64.SCRATCH_ZPREGX
 		pha
@@ -69,8 +240,7 @@ _hex_digits	.text "0123456789abcdef"	; can probably be reused for other stuff as
 	}}
 }
 
-
-asmsub  uword2hex  (uword value @ AY) -> clobbers(A,Y) -> ()  {
+asmsub  uword2hex  (uword value @ AY) clobbers(A,Y)  {
 	; ---- convert 16 bit uword in A/Y into 4-character hexadecimal string 'uword2hex.output' (0-terminated)
 	%asm {{
 		sta  c64.SCRATCH_ZPREG
@@ -87,93 +257,7 @@ output	.text  "0000", $00      ; 0-terminated output buffer (to make printing ea
 	}}
 }
 
-asmsub  uword2bcd  (uword value @ AY) -> clobbers(A,Y) -> ()  {
-	; Convert an 16 bit binary value to BCD
-	;
-	; This function converts a 16 bit binary value in A/Y into a 24 bit BCD. It
-	; works by transferring one bit a time from the source and adding it
-	; into a BCD value that is being doubled on each iteration. As all the
-	; arithmetic is being done in BCD the result is a binary to decimal
-	; conversion.
-	%asm {{
-		sta  c64.SCRATCH_ZPB1
-		sty  c64.SCRATCH_ZPREG
-		php
-		pla             ; read status register
-		and  #%00000100
-		sta  _had_irqd
-		sei				; disable interrupts because of bcd math
-		sed				; switch to decimal mode
-		lda  #0				; ensure the result is clear
-		sta  bcdbuff+0
-		sta  bcdbuff+1
-		sta  bcdbuff+2
-		ldy  #16			; the number of source bits
-
--		asl  c64.SCRATCH_ZPB1		; shift out one bit
-		rol  c64.SCRATCH_ZPREG
-		lda  bcdbuff+0		; and add into result
-		adc  bcdbuff+0
-		sta  bcdbuff+0
-		lda  bcdbuff+1		; propagating any carry
-		adc  bcdbuff+1
-		sta  bcdbuff+1
-		lda  bcdbuff+2		; ... thru whole result
-		adc  bcdbuff+2
-		sta  bcdbuff+2
-		dey				; and repeat for next bit
-		bne  -
-		cld				; back to binary
-		lda  _had_irqd
-		bne  +
-		cli				; enable interrupts again (only if they were enabled before)
-+		rts
-_had_irqd  .byte  0
-bcdbuff  .byte  0,0,0
-	}}
-}
-
-
-asmsub  uword2decimal  (uword value @ AY) -> clobbers(A) -> (ubyte @ Y)  {
-	; ---- convert 16 bit uword in A/Y into 0-terminated decimal string into memory  'uword2decimal.output'
-	;      returns length of resulting string in Y
-	%asm {{
-		jsr  uword2bcd
-		lda  uword2bcd.bcdbuff+2
-		clc
-		adc  #'0'
-		sta  output
-		ldy  #1
-		lda  uword2bcd.bcdbuff+1
-		jsr  +
-		lda  uword2bcd.bcdbuff+0
-
-+		pha
-		lsr  a
-		lsr  a
-		lsr  a
-		lsr  a
-		clc
-		adc  #'0'
-		sta  output,y
-		iny
-		pla
-		and  #$0f
-		adc  #'0'
-		sta  output,y
-		iny
-		lda  #0
-		sta  output,y
-		rts
-
-output  .text  "00000", $00     ; 0 terminated
-
-	}}
-
-}
-
-
-asmsub str2uword(str string @ AY) -> clobbers() -> (uword @ AY) {
+asmsub str2uword(str string @ AY) -> uword @ AY {
 	; -- returns the unsigned word value of the string number argument in AY
 	;    the number may NOT be preceded by a + sign and may NOT contain spaces
 	;    (any non-digit character will terminate the number string that is parsed)
@@ -227,8 +311,7 @@ _result_times_10     ; (W*4 + W)*2
 	}}
 }
 
-
-asmsub str2word(str string @ AY) -> clobbers() -> (word @ AY) {
+asmsub str2word(str string @ AY) -> word @ AY {
 	; -- returns the signed word value of the string number argument in AY
 	;    the number may be preceded by a + or - sign but may NOT contain spaces
 	;    (any non-digit character will terminate the number string that is parsed)
@@ -283,8 +366,7 @@ _negative	.byte  0
 	}}
 }
 
-
-asmsub  set_irqvec_excl() -> clobbers(A) -> ()  {
+asmsub  set_irqvec_excl() clobbers(A)  {
 	%asm {{
 		sei
 		lda  #<_irq_handler
@@ -303,7 +385,7 @@ _irq_handler	jsr  set_irqvec._irq_handler_init
 	}}
 }
 
-asmsub  set_irqvec() -> clobbers(A) -> ()  {
+asmsub  set_irqvec() clobbers(A)  {
 	%asm {{
 		sei
 		lda  #<_irq_handler
@@ -341,6 +423,7 @@ _irq_handler_init
 		dex
 		dex
 		dex
+		cld
 		rts
 
 _irq_handler_end
@@ -372,8 +455,7 @@ IRQ_SCRATCH_ZPWORD2	.word  0
 		}}
 }
 
-
-asmsub  restore_irqvec() -> clobbers() -> () {
+asmsub  restore_irqvec() {
 	%asm {{
 		sei
 		lda  #<c64.IRQDFRT
@@ -389,8 +471,7 @@ asmsub  restore_irqvec() -> clobbers() -> () {
 	}}
 }
 
-
-asmsub  set_rasterirq(uword rasterpos @ AY) -> clobbers(A) -> () {
+asmsub  set_rasterirq(uword rasterpos @ AY) clobbers(A) {
 	%asm {{
 		sei
 		jsr  _setup_raster_irq
@@ -431,7 +512,7 @@ _setup_raster_irq
 	}}
 }
 
-asmsub  set_rasterirq_excl(uword rasterpos @ AY) -> clobbers(A) -> () {
+asmsub  set_rasterirq_excl(uword rasterpos @ AY) clobbers(A) {
 	%asm {{
 		sei
 		jsr  set_rasterirq._setup_raster_irq
@@ -454,18 +535,16 @@ _raster_irq_handler
 }
 
 
-
 }  ; ------ end of block c64utils
 
 
 
 
-
-~ c64scr {
+c64scr {
 	; ---- this block contains (character) Screen and text I/O related functions ----
 
 
-asmsub  clear_screen (ubyte char @ A, ubyte color @ Y) -> clobbers(A) -> ()  {
+asmsub  clear_screen (ubyte char @ A, ubyte color @ Y) clobbers(A)  {
 	; ---- clear the character screen with the given fill character and character color.
 	;      (assumes screen and color matrix are at their default addresses)
 
@@ -480,8 +559,7 @@ asmsub  clear_screen (ubyte char @ A, ubyte color @ Y) -> clobbers(A) -> ()  {
 
 }
 
-
-asmsub  clear_screenchars (ubyte char @ A) -> clobbers(Y) -> ()  {
+asmsub  clear_screenchars (ubyte char @ A) clobbers(Y)  {
 	; ---- clear the character screen with the given fill character (leaves colors)
 	;      (assumes screen matrix is at the default address)
 	%asm {{
@@ -501,7 +579,7 @@ _loop		sta  c64.Screen,y
         }}
 }
 
-asmsub  clear_screencolors (ubyte color @ A) -> clobbers(Y) -> ()  {
+asmsub  clear_screencolors (ubyte color @ A) clobbers(Y)  {
 	; ---- clear the character screen colors with the given color (leaves characters).
 	;      (assumes color matrix is at the default address)
 	%asm {{
@@ -521,8 +599,7 @@ _loop		sta  c64.Colors,y
         }}
 }
 
-
-asmsub  scroll_left_full  (ubyte alsocolors @ Pc) -> clobbers(A, Y) -> ()  {
+asmsub  scroll_left_full  (ubyte alsocolors @ Pc) clobbers(A, Y)  {
 	; ---- scroll the whole screen 1 character to the left
 	;      contents of the rightmost column are unchanged, you should clear/refill this yourself
 	;      Carry flag determines if screen color data must be scrolled too
@@ -582,8 +659,7 @@ _scroll_screen  ; scroll the screen memory
 	}}
 }
 
-
-asmsub  scroll_right_full  (ubyte alsocolors @ Pc) -> clobbers(A) -> ()  {
+asmsub  scroll_right_full  (ubyte alsocolors @ Pc) clobbers(A)  {
 	; ---- scroll the whole screen 1 character to the right
 	;      contents of the leftmost column are unchanged, you should clear/refill this yourself
 	;      Carry flag determines if screen color data must be scrolled too
@@ -635,8 +711,7 @@ _scroll_screen  ; scroll the screen memory
 	}}
 }
 
-
-asmsub  scroll_up_full  (ubyte alsocolors @ Pc) -> clobbers(A) -> ()  {
+asmsub  scroll_up_full  (ubyte alsocolors @ Pc) clobbers(A)  {
 	; ---- scroll the whole screen 1 character up
 	;      contents of the bottom row are unchanged, you should refill/clear this yourself
 	;      Carry flag determines if screen color data must be scrolled too
@@ -688,8 +763,7 @@ _scroll_screen  ; scroll the screen memory
 	}}
 }
 
-
-asmsub  scroll_down_full  (ubyte alsocolors @ Pc) -> clobbers(A) -> ()  {
+asmsub  scroll_down_full  (ubyte alsocolors @ Pc) clobbers(A)  {
 	; ---- scroll the whole screen 1 character down
 	;      contents of the top row are unchanged, you should refill/clear this yourself
 	;      Carry flag determines if screen color data must be scrolled too
@@ -742,8 +816,7 @@ _scroll_screen  ; scroll the screen memory
 }
 
 
-
-asmsub  print (str text @ AY) -> clobbers(A,Y) -> ()  {
+asmsub  print (str text @ AY) clobbers(A,Y)  {
 	; ---- print null terminated string from A/Y
 	; note: the compiler contains an optimization that will replace
 	;       a call to this subroutine with a string argument of just one char,
@@ -761,8 +834,7 @@ asmsub  print (str text @ AY) -> clobbers(A,Y) -> ()  {
 	}}
 }
 
-
-asmsub  print_ub0  (ubyte value @ A) -> clobbers(A,Y) -> ()  {
+asmsub  print_ub0  (ubyte value @ A) clobbers(A,Y)  {
 	; ---- print the ubyte in A in decimal form, with left padding 0s (3 positions total)
 	%asm {{
 		stx  c64.SCRATCH_ZPREGX
@@ -770,17 +842,16 @@ asmsub  print_ub0  (ubyte value @ A) -> clobbers(A,Y) -> ()  {
 		pha
 		tya
 		jsr  c64.CHROUT
-		txa
-		jsr  c64.CHROUT
 		pla
 		jsr  c64.CHROUT
+		txa
+		jsr  c64.CHROUT
 		ldx  c64.SCRATCH_ZPREGX
 		rts
 	}}
 }
 
-
-asmsub  print_ub  (ubyte value @ A) -> clobbers(A,Y) -> ()  {
+asmsub  print_ub  (ubyte value @ A) clobbers(A,Y)  {
 	; ---- print the ubyte in A in decimal form, without left padding 0s
 	%asm {{
 		stx  c64.SCRATCH_ZPREGX
@@ -788,22 +859,21 @@ asmsub  print_ub  (ubyte value @ A) -> clobbers(A,Y) -> ()  {
 _print_byte_digits
 		pha
 		cpy  #'0'
-		bne  _print_hundreds
-		cpx  #'0'
-		bne  _print_tens
-		jmp  _end
-_print_hundreds	tya
+		beq  +
+		tya
 		jsr  c64.CHROUT
-_print_tens	txa
-		jsr  c64.CHROUT
-_end		pla
++       pla
+        cmp  #'0'
+        beq  +
+        jsr  c64.CHROUT
++       txa
 		jsr  c64.CHROUT
 		ldx  c64.SCRATCH_ZPREGX
 		rts
 	}}
 }
 
-asmsub  print_b  (byte value @ A) -> clobbers(A,Y) -> ()  {
+asmsub  print_b  (byte value @ A) clobbers(A,Y)  {
 	; ---- print the byte in A in decimal form, without left padding 0s
 	%asm {{
 		stx  c64.SCRATCH_ZPREGX
@@ -820,8 +890,7 @@ asmsub  print_b  (byte value @ A) -> clobbers(A,Y) -> ()  {
 	}}
 }
 
-
-asmsub  print_ubhex  (ubyte prefix @ Pc, ubyte value @ A) -> clobbers(A,Y) -> ()  {
+asmsub  print_ubhex  (ubyte value @ A, ubyte prefix @ Pc) clobbers(A,Y)  {
 	; ---- print the ubyte in A in hex form (if Carry is set, a radix prefix '$' is printed as well)
 	%asm {{
 		stx  c64.SCRATCH_ZPREGX
@@ -839,8 +908,7 @@ asmsub  print_ubhex  (ubyte prefix @ Pc, ubyte value @ A) -> clobbers(A,Y) -> ()
 	}}
 }
 
-
-asmsub  print_ubbin  (ubyte prefix @ Pc, ubyte value @ A) -> clobbers(A,Y) ->()  {
+asmsub  print_ubbin  (ubyte value @ A, ubyte prefix @ Pc) clobbers(A,Y)  {
 	; ---- print the ubyte in A in binary form (if Carry is set, a radix prefix '%' is printed as well)
 	%asm {{
 		stx  c64.SCRATCH_ZPREGX
@@ -861,8 +929,7 @@ asmsub  print_ubbin  (ubyte prefix @ Pc, ubyte value @ A) -> clobbers(A,Y) ->()
 	}}
 }
 
-
-asmsub  print_uwbin  (ubyte prefix @ Pc, uword value @ AY) -> clobbers(A,Y) ->()  {
+asmsub  print_uwbin  (uword value @ AY, ubyte prefix @ Pc) clobbers(A,Y)  {
 	; ---- print the uword in A/Y in binary form (if Carry is set, a radix prefix '%' is printed as well)
 	%asm {{
 		pha
@@ -874,8 +941,7 @@ asmsub  print_uwbin  (ubyte prefix @ Pc, uword value @ AY) -> clobbers(A,Y) ->()
 	}}
 }
 
-
-asmsub print_uwhex  (ubyte prefix @ Pc, uword value @ AY) -> clobbers(A,Y) -> ()  {
+asmsub print_uwhex  (uword value @ AY, ubyte prefix @ Pc) clobbers(A,Y)  {
 	; ---- print the uword in A/Y in hexadecimal form (4 digits)
 	;      (if Carry is set, a radix prefix '$' is printed as well)
 	%asm {{
@@ -888,55 +954,48 @@ asmsub print_uwhex  (ubyte prefix @ Pc, uword value @ AY) -> clobbers(A,Y) -> ()
 	}}
 }
 
-
-asmsub  print_uw0  (uword value @ AY) -> clobbers(A,Y) -> ()  {
+asmsub  print_uw0  (uword value @ AY) clobbers(A,Y)  {
 	; ---- print the uword in A/Y in decimal form, with left padding 0s (5 positions total)
 	%asm {{
+	    stx  c64.SCRATCH_ZPREGX
 		jsr  c64utils.uword2decimal
 		ldy  #0
--		lda  c64utils.uword2decimal.output,y
+-		lda  c64utils.uword2decimal.decTenThousands,y
+        beq  +
 		jsr  c64.CHROUT
 		iny
-		cpy  #5
 		bne  -
++		ldx  c64.SCRATCH_ZPREGX
 		rts
 	}}
 }
 
-
-asmsub  print_uw  (uword value @ AY) -> clobbers(A,Y) -> ()  {
+asmsub  print_uw  (uword value @ AY) clobbers(A,Y)  {
 	; ---- print the uword in A/Y in decimal form, without left padding 0s
 	%asm {{
+	    stx  c64.SCRATCH_ZPREGX
 		jsr  c64utils.uword2decimal
 		ldy  #0
-		lda  c64utils.uword2decimal.output
+-		lda  c64utils.uword2decimal.decTenThousands,y
+		beq  _allzero
 		cmp  #'0'
-		bne  _pr_decimal
-		iny
-		lda  c64utils.uword2decimal.output+1
-		cmp  #'0'
-		bne  _pr_decimal
-		iny
-		lda  c64utils.uword2decimal.output+2
-		cmp  #'0'
-		bne  _pr_decimal
-		iny
-		lda  c64utils.uword2decimal.output+3
-		cmp  #'0'
-		bne  _pr_decimal
+		bne  _gotdigit
 		iny
+		bne  -
 
-_pr_decimal
-		lda  c64utils.uword2decimal.output,y
+_gotdigit
 		jsr  c64.CHROUT
 		iny
-		cpy  #5
-		bcc  _pr_decimal
+		lda  c64utils.uword2decimal.decTenThousands,y
+		bne  _gotdigit
 		rts
+_allzero
+        lda  #'0'
+        jmp  c64.CHROUT
 	}}
 }
 
-asmsub  print_w  (word value @ AY) -> clobbers(A,Y) -> ()  {
+asmsub  print_w  (word value @ AY) clobbers(A,Y)  {
 	; ---- print the (signed) word in A/Y in decimal form, without left padding 0's
 	%asm {{
 		cpy  #0
@@ -957,7 +1016,7 @@ asmsub  print_w  (word value @ AY) -> clobbers(A,Y) -> ()  {
 	}}
 }
 
-asmsub  input_chars  (uword buffer @ AY) -> clobbers(A) -> (ubyte @ Y)  {
+asmsub  input_chars  (uword buffer @ AY) clobbers(A) -> ubyte @ Y  {
 	; ---- Input a string (max. 80 chars) from the keyboard. Returns length in Y. (string is terminated with a 0 byte as well)
 	;      It assumes the keyboard is selected as I/O channel!
 
@@ -978,7 +1037,7 @@ asmsub  input_chars  (uword buffer @ AY) -> clobbers(A) -> (ubyte @ Y)  {
 	}}
 }
 
-asmsub  setchr  (ubyte col @Y, ubyte row @A) -> clobbers(A) -> ()  {
+asmsub  setchr  (ubyte col @Y, ubyte row @A) clobbers(A)  {
 	; ---- set the character in SCRATCH_ZPB1 on the screen matrix at the given position
 	%asm {{
 		sty  c64.SCRATCH_ZPREG
@@ -1000,7 +1059,7 @@ _screenrows	.word  $0400 + range(0, 1000, 40)
 	}}
 }
 
-asmsub  getchr  (ubyte col @Y, ubyte row @A) -> clobbers(Y) -> (ubyte @ A) {
+asmsub  getchr  (ubyte col @Y, ubyte row @A) clobbers(Y) -> ubyte @ A {
 	; ---- get the character in the screen matrix at the given location
 	%asm  {{
 		sty  c64.SCRATCH_ZPB1
@@ -1019,7 +1078,7 @@ _mod		lda  $ffff		; modified
 	}}
 }
 
-asmsub  setclr  (ubyte col @Y, ubyte row @A) -> clobbers(A) -> ()  {
+asmsub  setclr  (ubyte col @Y, ubyte row @A) clobbers(A)  {
 	; ---- set the color in SCRATCH_ZPB1 on the screen matrix at the given position
 	%asm {{
 		sty  c64.SCRATCH_ZPREG
@@ -1041,7 +1100,7 @@ _colorrows	.word  $d800 + range(0, 1000, 40)
 	}}
 }
 
-asmsub  getclr  (ubyte col @Y, ubyte row @A) -> clobbers(Y) -> (ubyte @ A) {
+asmsub  getclr  (ubyte col @Y, ubyte row @A) clobbers(Y) -> ubyte @ A {
 	; ---- get the color in the screen color matrix at the given location
 	%asm  {{
 		sty  c64.SCRATCH_ZPB1
@@ -1063,7 +1122,7 @@ _mod		lda  $ffff		; modified
 sub  setcc  (ubyte column, ubyte row, ubyte char, ubyte color)  {
 	; ---- set char+color at the given position on the screen
 	%asm {{
-		lda  setcc_row
+		lda  row
 		asl  a
 		tay
 		lda  setchr._screenrows+1,y
@@ -1072,21 +1131,21 @@ sub  setcc  (ubyte column, ubyte row, ubyte char, ubyte color)  {
 		sta  _colormod+2
 		lda  setchr._screenrows,y
 		clc
-		adc  setcc_column
+		adc  column
 		sta  _charmod+1
 		sta  _colormod+1
 		bcc  +
 		inc  _charmod+2
 		inc  _colormod+2
-+		lda  setcc_char
++		lda  char
 _charmod	sta  $ffff		; modified
-		lda  setcc_color
+		lda  color
 _colormod	sta  $ffff		; modified
 		rts
 	}}
 }
 
-asmsub  plot  (ubyte col @ Y, ubyte row @ A) -> clobbers(A) -> () {
+asmsub  plot  (ubyte col @ Y, ubyte row @ A) clobbers(A) {
 	; ---- safe wrapper around PLOT kernel routine, to save the X register.
 	%asm  {{
 		stx  c64.SCRATCH_ZPREGX

compiler/res/prog8lib/math.asm

@@ -643,3 +643,40 @@ mul_word_40	.proc
 		sta  c64.ESTACK_HI+1,x
 		rts
 		.pend
+
+sign_b		.proc
+		lda  c64.ESTACK_LO+1,x
+		beq  _sign_zero
+		bmi  _sign_neg
+_sign_pos	lda  #1
+		sta  c64.ESTACK_LO+1,x
+		rts
+_sign_neg	lda  #-1
+_sign_zero	sta  c64.ESTACK_LO+1,x
+		rts
+		.pend
+
+sign_ub		.proc
+		lda  c64.ESTACK_LO+1,x
+		beq  sign_b._sign_zero
+		bne  sign_b._sign_pos
+		.pend
+
+sign_w		.proc
+		lda  c64.ESTACK_HI+1,x
+		bmi  sign_b._sign_neg
+		beq  sign_ub
+		bne  sign_b._sign_pos
+		.pend
+
+sign_uw		.proc
+		lda  c64.ESTACK_HI+1,x
+		beq  _sign_possibly_zero
+_sign_pos	lda  #1
+		sta  c64.ESTACK_LO+1,x
+		rts
+_sign_possibly_zero	lda  c64.ESTACK_LO+1,x
+		bne  _sign_pos
+		sta  c64.ESTACK_LO+1,x
+		rts
+		.pend

compiler/res/prog8lib/math.p8

@@ -6,6 +6,6 @@
 
 %import c64lib
 
-~ math {
+math {
 	%asminclude "library:math.asm", ""
 }

compiler/res/prog8lib/prog8lib.asm

@@ -36,6 +36,17 @@ init_system	.proc
 		.pend
 
 
+read_byte_from_address	.proc
+	; -- read the byte from the memory address on the top of the stack, return in A (stack remains unchanged)
+		lda  c64.ESTACK_LO+1,x
+		ldy  c64.ESTACK_HI+1,x
+		sta  (+) +1
+		sty  (+) +2
++		lda  $ffff		; modified
+		rts
+		.pend
+
+
 add_a_to_zpword	.proc
 	; -- add ubyte in A to the uword in c64.SCRATCH_ZPWORD1
 		clc
@@ -705,7 +716,7 @@ func_sin8	.proc
 		lda  _sinecos8,y
 		sta  c64.ESTACK_LO+1,x
 		rts
-_sinecos8	.char  127 * sin(range(256+64) * rad(360.0/256.0))
+_sinecos8	.char  trunc(127.0 * sin(range(256+64) * rad(360.0/256.0)))
 		.pend
 
 func_sin8u	.proc
@@ -713,7 +724,7 @@ func_sin8u	.proc
 		lda  _sinecos8u,y
 		sta  c64.ESTACK_LO+1,x
 		rts
-_sinecos8u	.byte  128 + 127.5 * sin(range(256+64) * rad(360.0/256.0))
+_sinecos8u	.byte  trunc(128.0 + 127.5 * sin(range(256+64) * rad(360.0/256.0)))
 		.pend
 
 func_sin16	.proc
@@ -724,7 +735,7 @@ func_sin16	.proc
 		sta  c64.ESTACK_HI+1,x
 		rts
 
-_  :=  32767 * sin(range(256+64) * rad(360.0/256.0))
+_  :=  trunc(32767.0 * sin(range(256+64) * rad(360.0/256.0)))
 _sinecos8lo     .byte  <_
 _sinecos8hi     .byte  >_
 		.pend
@@ -737,7 +748,7 @@ func_sin16u	.proc
 		sta  c64.ESTACK_HI+1,x
 		rts
 
-_  :=  32768 + 32767.5 * sin(range(256+64) * rad(360.0/256.0))
+_  :=  trunc(32768.0 + 32767.5 * sin(range(256+64) * rad(360.0/256.0)))
 _sinecos8ulo     .byte  <_
 _sinecos8uhi     .byte  >_
 		.pend
@@ -840,11 +851,12 @@ func_all_w	.proc
 		bne  +
 		iny
 		lda  (c64.SCRATCH_ZPWORD1),y
-		bne  +
+		bne  ++
 		lda  #0
 		sta  c64.ESTACK_LO+1,x
 		rts
 +		iny
++		iny
 _cmp_mod	cpy  #255		; modified
 		bne  -
 		lda  #1
@@ -1372,3 +1384,378 @@ _mod2b          lda  #0                         ; self-modified
 _done		rts
 		.pend
 
+
+sort_ub		.proc
+		; 8bit unsigned sort
+		; sorting subroutine coded by mats rosengren (mats.rosengren@esa.int)
+		; input:  address of array to sort in c64.SCRATCH_ZPWORD1, length in c64.SCRATCH_ZPB1
+		; first, put pointer BEFORE array
+		lda  c64.SCRATCH_ZPWORD1
+		bne  +
+		dec  c64.SCRATCH_ZPWORD1+1
++		dec  c64.SCRATCH_ZPWORD1
+_sortloop	ldy  c64.SCRATCH_ZPB1		;start of subroutine sort
+		lda  (c64.SCRATCH_ZPWORD1),y	;last value in (what is left of) sequence to be sorted
+		sta  c64.SCRATCH_ZPREG		;save value. will be over-written by largest number
+		jmp  _l2
+_l1		dey
+		beq  _l3
+		lda  (c64.SCRATCH_ZPWORD1),y
+		cmp  c64.SCRATCH_ZPWORD2+1
+		bcc  _l1
+_l2		sty  c64.SCRATCH_ZPWORD2	;index of potentially largest value
+		sta  c64.SCRATCH_ZPWORD2+1	;potentially largest value
+		jmp  _l1
+_l3		ldy  c64.SCRATCH_ZPB1		;where the largest value shall be put
+		lda  c64.SCRATCH_ZPWORD2+1	;the largest value
+		sta  (c64.SCRATCH_ZPWORD1),y	;put largest value in place
+		ldy  c64.SCRATCH_ZPWORD2	;index of free space
+		lda  c64.SCRATCH_ZPREG		;the over-written value
+		sta  (c64.SCRATCH_ZPWORD1),y	;put the over-written value in the free space
+		dec  c64.SCRATCH_ZPB1		;end of the shorter sequence still left
+		bne  _sortloop			;start working with the shorter sequence
+		rts
+		.pend
+
+
+sort_b		.proc
+		; 8bit signed sort
+		; sorting subroutine coded by mats rosengren (mats.rosengren@esa.int)
+		; input:  address of array to sort in c64.SCRATCH_ZPWORD1, length in c64.SCRATCH_ZPB1
+		; first, put pointer BEFORE array
+		lda  c64.SCRATCH_ZPWORD1
+		bne  +
+		dec  c64.SCRATCH_ZPWORD1+1
++		dec  c64.SCRATCH_ZPWORD1
+_sortloop	ldy  c64.SCRATCH_ZPB1		;start of subroutine sort
+		lda  (c64.SCRATCH_ZPWORD1),y	;last value in (what is left of) sequence to be sorted
+		sta  c64.SCRATCH_ZPREG		;save value. will be over-written by largest number
+		jmp  _l2
+_l1		dey
+		beq  _l3
+		lda  (c64.SCRATCH_ZPWORD1),y
+		cmp  c64.SCRATCH_ZPWORD2+1
+		bmi  _l1
+_l2		sty  c64.SCRATCH_ZPWORD2	;index of potentially largest value
+		sta  c64.SCRATCH_ZPWORD2+1	;potentially largest value
+		jmp  _l1
+_l3		ldy  c64.SCRATCH_ZPB1		;where the largest value shall be put
+		lda  c64.SCRATCH_ZPWORD2+1	;the largest value
+		sta  (c64.SCRATCH_ZPWORD1),y	;put largest value in place
+		ldy  c64.SCRATCH_ZPWORD2	;index of free space
+		lda  c64.SCRATCH_ZPREG		;the over-written value
+		sta  (c64.SCRATCH_ZPWORD1),y	;put the over-written value in the free space
+		dec  c64.SCRATCH_ZPB1		;end of the shorter sequence still left
+		bne  _sortloop			;start working with the shorter sequence
+		rts
+		.pend
+
+
+sort_uw		.proc
+		; 16bit unsigned sort
+		; sorting subroutine coded by mats rosengren (mats.rosengren@esa.int)
+		; input:  address of array to sort in c64.SCRATCH_ZPWORD1, length in c64.SCRATCH_ZPB1
+		; first: subtract 2 of the pointer
+		asl  c64.SCRATCH_ZPB1		; *2 because words
+		lda  c64.SCRATCH_ZPWORD1
+		sec
+		sbc  #2
+		sta  c64.SCRATCH_ZPWORD1
+		bcs  _sort_loop
+		dec  c64.SCRATCH_ZPWORD1+1
+_sort_loop	ldy  c64.SCRATCH_ZPB1    	;start of subroutine sort
+		lda  (c64.SCRATCH_ZPWORD1),y    ;last value in (what is left of) sequence to be sorted
+		sta  _work3          		;save value. will be over-written by largest number
+		iny
+		lda  (c64.SCRATCH_ZPWORD1),y
+		sta  _work3+1
+		dey
+		jmp  _l2
+_l1		dey
+		dey
+		beq  _l3
+		iny
+		lda  (c64.SCRATCH_ZPWORD1),y
+		dey
+		cmp  c64.SCRATCH_ZPWORD2+1
+		bne  +
+		lda  (c64.SCRATCH_ZPWORD1),y
+		cmp  c64.SCRATCH_ZPWORD2
++		bcc  _l1
+_l2		sty  _work1          		;index of potentially largest value
+		lda  (c64.SCRATCH_ZPWORD1),y
+		sta  c64.SCRATCH_ZPWORD2          ;potentially largest value
+		iny
+		lda  (c64.SCRATCH_ZPWORD1),y
+		sta  c64.SCRATCH_ZPWORD2+1
+		dey
+		jmp  _l1
+_l3		ldy  c64.SCRATCH_ZPB1           ;where the largest value shall be put
+		lda  c64.SCRATCH_ZPWORD2          ;the largest value
+		sta  (c64.SCRATCH_ZPWORD1),y      ;put largest value in place
+		iny
+		lda  c64.SCRATCH_ZPWORD2+1
+		sta  (c64.SCRATCH_ZPWORD1),y
+		ldy  _work1         		 ;index of free space
+		lda  _work3          		;the over-written value
+		sta  (c64.SCRATCH_ZPWORD1),y      ;put the over-written value in the free space
+		iny
+		lda  _work3+1
+		sta  (c64.SCRATCH_ZPWORD1),y
+		dey
+		dec  c64.SCRATCH_ZPB1           ;end of the shorter sequence still left
+		dec  c64.SCRATCH_ZPB1
+		bne  _sort_loop           ;start working with the shorter sequence
+		rts
+_work1	.byte  0
+_work3	.word  0
+		.pend
+
+
+sort_w		.proc
+		; 16bit signed sort
+		; sorting subroutine coded by mats rosengren (mats.rosengren@esa.int)
+		; input:  address of array to sort in c64.SCRATCH_ZPWORD1, length in c64.SCRATCH_ZPB1
+		; first: subtract 2 of the pointer
+		asl  c64.SCRATCH_ZPB1		; *2 because words
+		lda  c64.SCRATCH_ZPWORD1
+		sec
+		sbc  #2
+		sta  c64.SCRATCH_ZPWORD1
+		bcs  _sort_loop
+		dec  c64.SCRATCH_ZPWORD1+1
+_sort_loop	ldy  c64.SCRATCH_ZPB1    	;start of subroutine sort
+		lda  (c64.SCRATCH_ZPWORD1),y    ;last value in (what is left of) sequence to be sorted
+		sta  _work3          		;save value. will be over-written by largest number
+		iny
+		lda  (c64.SCRATCH_ZPWORD1),y
+		sta  _work3+1
+		dey
+		jmp  _l2
+_l1		dey
+		dey
+		beq  _l3
+		lda  (c64.SCRATCH_ZPWORD1),y
+		cmp  c64.SCRATCH_ZPWORD2
+		iny
+		lda  (c64.SCRATCH_ZPWORD1),y
+		dey
+		sbc  c64.SCRATCH_ZPWORD2+1
+		bvc  +
+		eor  #$80
++		bmi  _l1
+_l2		sty  _work1          		;index of potentially largest value
+		lda  (c64.SCRATCH_ZPWORD1),y
+		sta  c64.SCRATCH_ZPWORD2          ;potentially largest value
+		iny
+		lda  (c64.SCRATCH_ZPWORD1),y
+		sta  c64.SCRATCH_ZPWORD2+1
+		dey
+		jmp  _l1
+_l3		ldy  c64.SCRATCH_ZPB1           ;where the largest value shall be put
+		lda  c64.SCRATCH_ZPWORD2          ;the largest value
+		sta  (c64.SCRATCH_ZPWORD1),y      ;put largest value in place
+		iny
+		lda  c64.SCRATCH_ZPWORD2+1
+		sta  (c64.SCRATCH_ZPWORD1),y
+		ldy  _work1         		 ;index of free space
+		lda  _work3          		;the over-written value
+		sta  (c64.SCRATCH_ZPWORD1),y      ;put the over-written value in the free space
+		iny
+		lda  _work3+1
+		sta  (c64.SCRATCH_ZPWORD1),y
+		dey
+		dec  c64.SCRATCH_ZPB1           ;end of the shorter sequence still left
+		dec  c64.SCRATCH_ZPB1
+		bne  _sort_loop           ;start working with the shorter sequence
+		rts
+_work1	.byte  0
+_work3	.word  0
+		.pend
+
+
+reverse_b	.proc
+		; --- reverse an array of bytes (in-place)
+		; inputs:  pointer to array in c64.SCRATCH_ZPWORD1, length in A
+_left_index = c64.SCRATCH_ZPWORD2
+_right_index = c64.SCRATCH_ZPWORD2+1
+		pha
+		sec
+		sbc  #1
+		sta  _left_index
+		lda  #0
+		sta  _right_index
+		pla
+		lsr  a
+		tay
+_loop		sty  c64.SCRATCH_ZPREG
+		ldy  _left_index
+		lda  (c64.SCRATCH_ZPWORD1),y
+		pha
+		ldy  _right_index
+		lda  (c64.SCRATCH_ZPWORD1),y
+		ldy  _left_index
+		sta  (c64.SCRATCH_ZPWORD1),y
+		pla
+		ldy  _right_index
+		sta  (c64.SCRATCH_ZPWORD1),y
+		inc  _right_index
+		dec  _left_index
+		ldy  c64.SCRATCH_ZPREG
+		dey
+		bne  _loop
+		rts
+		.pend
+
+
+reverse_w	.proc
+		; --- reverse an array of words (in-place)
+		; inputs:  pointer to array in c64.SCRATCH_ZPWORD1, length in A
+_left_index = c64.SCRATCH_ZPWORD2
+_right_index = c64.SCRATCH_ZPWORD2+1
+		pha
+		asl  a     ; *2 because words
+		sec
+		sbc  #2
+		sta  _left_index
+		lda  #0
+		sta  _right_index
+		pla
+		lsr  a
+		pha
+		tay
+		; first reverse the lsbs
+_loop_lo	sty  c64.SCRATCH_ZPREG
+		ldy  _left_index
+		lda  (c64.SCRATCH_ZPWORD1),y
+		pha
+		ldy  _right_index
+		lda  (c64.SCRATCH_ZPWORD1),y
+		ldy  _left_index
+		sta  (c64.SCRATCH_ZPWORD1),y
+		pla
+		ldy  _right_index
+		sta  (c64.SCRATCH_ZPWORD1),y
+		inc  _right_index
+		inc  _right_index
+		dec  _left_index
+		dec  _left_index
+		ldy  c64.SCRATCH_ZPREG
+		dey
+		bne  _loop_lo
+		; now reverse the msbs
+		dec  _right_index
+		inc  _left_index
+		inc  _left_index
+		inc  _left_index
+		pla
+		tay
+_loop_hi	sty  c64.SCRATCH_ZPREG
+		ldy  _left_index
+		lda  (c64.SCRATCH_ZPWORD1),y
+		pha
+		ldy  _right_index
+		lda  (c64.SCRATCH_ZPWORD1),y
+		ldy  _left_index
+		sta  (c64.SCRATCH_ZPWORD1),y
+		pla
+		ldy  _right_index
+		sta  (c64.SCRATCH_ZPWORD1),y
+		dec  _right_index
+		dec  _right_index
+		inc  _left_index
+		inc  _left_index
+		ldy  c64.SCRATCH_ZPREG
+		dey
+		bne  _loop_hi
+
+		rts
+		.pend
+
+ror2_mem_ub	.proc
+		; -- in-place 8-bit ror of byte at memory location on stack
+		inx
+		lda  c64.ESTACK_LO,x
+		sta  c64.SCRATCH_ZPWORD1
+		lda  c64.ESTACK_HI,x
+		sta  c64.SCRATCH_ZPWORD1+1
+		ldy  #0
+		lda  (c64.SCRATCH_ZPWORD1),y
+		lsr  a
+		bcc  +
+		ora  #$80
++		sta  (c64.SCRATCH_ZPWORD1),y
+		rts
+		.pend
+
+rol2_mem_ub	.proc
+		; -- in-place 8-bit rol of byte at memory location on stack
+		;"  lda  ${number.toHex()} |  cmp  #\$80 |  rol  a |  sta  ${number.toHex()}"
+		inx
+		lda  c64.ESTACK_LO,x
+		sta  c64.SCRATCH_ZPWORD1
+		lda  c64.ESTACK_HI,x
+		sta  c64.SCRATCH_ZPWORD1+1
+		ldy  #0
+		lda  (c64.SCRATCH_ZPWORD1),y
+		cmp  #$80
+		rol  a
+		sta  (c64.SCRATCH_ZPWORD1),y
+		rts
+		.pend
+
+lsl_array_b	.proc
+		.warn "lsl_array_b"		; TODO
+		.pend
+
+lsl_array_w	.proc
+		.warn "lsl_array_w"		; TODO
+		.pend
+
+lsr_array_ub	.proc
+		.warn "lsr_array_ub"		; TODO
+		.pend
+
+lsr_array_b	.proc
+		.warn "lsr_array_b"		; TODO
+		.pend
+
+lsr_array_uw	.proc
+		.warn "lsr_array_uw"		; TODO
+		.pend
+
+lsr_array_w	.proc
+		.warn "lsr_array_w"		; TODO
+		.pend
+
+rol_array_ub	.proc
+		.warn "rol_array_ub"		; TODO
+		.pend
+
+rol_array_uw	.proc
+		.warn "rol_array_uw"		; TODO
+		.pend
+
+rol2_array_ub	.proc
+		.warn "rol2_array_ub"		; TODO
+		.pend
+
+rol2_array_uw	.proc
+		.warn "rol2_array_uw"		; TODO
+		.pend
+
+ror_array_ub	.proc
+		.warn "ror_array_ub"		; TODO
+		.pend
+
+ror_array_uw	.proc
+		.warn "ror_array_uw"		; TODO
+		.pend
+
+ror2_array_ub	.proc
+		.warn "ror2_array_ub"		; TODO
+		.pend
+
+ror2_array_uw	.proc
+		.warn "ror2_array_uw"		; TODO
+		.pend

compiler/res/prog8lib/prog8lib.p8

@@ -6,6 +6,6 @@
 
 %import c64lib
 
-~ prog8_lib {
+prog8_lib {
 	%asminclude "library:prog8lib.asm", ""
 }

compiler/res/version.txt

@@ -1 +1 @@
-1.8
+1.70

compiler/src/prog8/CompilerMain.kt

@@ -1,38 +1,25 @@
 package prog8
 
-import prog8.ast.*
-import prog8.astvm.AstVm
+import kotlinx.cli.*
+import prog8.ast.base.AstException
 import prog8.compiler.*
-import prog8.compiler.target.c64.AsmGen
-import prog8.compiler.target.c64.C64Zeropage
-import prog8.optimizing.constantFold
-import prog8.optimizing.optimizeStatements
-import prog8.optimizing.simplifyExpressions
+import prog8.compiler.target.CompilationTarget
+import prog8.compiler.target.c64.C64MachineDefinition
+import prog8.compiler.target.c64.Petscii
+import prog8.compiler.target.c64.codegen.AsmGen
 import prog8.parser.ParsingFailedError
-import prog8.parser.importLibraryModule
-import prog8.parser.importModule
-import prog8.parser.moduleName
-import java.io.File
-import java.io.PrintStream
-import java.lang.Exception
-import java.nio.file.Paths
+import prog8.vm.astvm.AstVm
+import java.io.IOException
+import java.nio.file.FileSystems
+import java.nio.file.Path
+import java.nio.file.StandardWatchEventKinds
+import java.time.LocalDateTime
 import kotlin.system.exitProcess
-import kotlin.system.measureTimeMillis
 
 
 fun main(args: Array<String>) {
-
-    // check if the user wants to launch the VM instead
-    if("-vm" in args) {
-        val newArgs = args.toMutableList()
-        newArgs.remove("-vm")
-        return stackVmMain(newArgs.toTypedArray())
-    }
-
     printSoftwareHeader("compiler")
 
-    if (args.isEmpty())
-        usage()
     compileMain(args)
 }
 
@@ -43,210 +30,122 @@ internal fun printSoftwareHeader(what: String) {
 }
 
 
-private fun compileMain(args: Array<String>) {
-    var emulatorToStart = ""
-    var moduleFile = ""
-    var writeVmCode = false
-    var writeAssembly = true
-    var optimize = true
-    var optimizeInlining = true
-    var launchAstVm = false
-    for (arg in args) {
-        if(arg=="-emu")
-            emulatorToStart = "x64"
-        else if(arg=="-emu2")
-            emulatorToStart = "x64sc"
-        else if(arg=="-writevm")
-            writeVmCode = true
-        else if(arg=="-noasm")
-            writeAssembly = false
-        else if(arg=="-noopt")
-            optimize = false
-        else if(arg=="-nooptinline")
-            optimizeInlining = false
-        else if(arg=="-avm")
-            launchAstVm = true
-        else if(!arg.startsWith("-"))
-            moduleFile = arg
-        else
-            usage()
-    }
-    if(moduleFile.isBlank())
-        usage()
+fun pathFrom(stringPath: String, vararg rest: String): Path  = FileSystems.getDefault().getPath(stringPath, *rest)
 
-    val filepath = Paths.get(moduleFile).normalize()
-    var programname = "?"
-    lateinit var programAst: Program
+
+private fun compileMain(args: Array<String>) {
+    val cli = CommandLineInterface("prog8compiler")
+    val startEmulator by cli.flagArgument("-emu", "auto-start the Vice C-64 emulator after successful compilation")
+    val outputDir by cli.flagValueArgument("-out", "directory", "directory for output files instead of current directory", ".")
+    val dontWriteAssembly by cli.flagArgument("-noasm", "don't create assembly code")
+    val dontOptimize by cli.flagArgument("-noopt", "don't perform any optimizations")
+    val launchSimulator by cli.flagArgument("-sim", "launch the builtin execution simulator after compilation")
+    val watchMode by cli.flagArgument("-watch", "continuous compilation mode (watches for file changes), greatly increases compilation speed")
+    val compilationTarget by cli.flagValueArgument("-target", "compilertarget", "target output of the compiler, currently only 'c64' (C64 6502 assembly) available", "c64")
+    val moduleFiles by cli.positionalArgumentsList("modules", "main module file(s) to compile", minArgs = 1)
 
     try {
-        val totalTime = measureTimeMillis {
-            // import main module and everything it needs
-            println("Parsing...")
-            programAst = Program(moduleName(filepath.fileName), mutableListOf())
-            importModule(programAst, filepath)
+        cli.parse(args)
+    } catch (e: Exception) {
+        exitProcess(1)
+    }
 
-            val compilerOptions = determineCompilationOptions(programAst)
-            if (compilerOptions.launcher == LauncherType.BASIC && compilerOptions.output != OutputType.PRG)
-                throw ParsingFailedError("${programAst.modules.first().position} BASIC launcher requires output type PRG.")
-
-            // if we're producing a PRG or BASIC program, include the c64utils and c64lib libraries
-            if(compilerOptions.launcher==LauncherType.BASIC || compilerOptions.output==OutputType.PRG) {
-                importLibraryModule(programAst, "c64lib")
-                importLibraryModule(programAst, "c64utils")
-            }
-
-            // always import prog8lib and math
-            importLibraryModule(programAst, "math")
-            importLibraryModule(programAst, "prog8lib")
-
-
-            // perform initial syntax checks and constant folding
-            println("Syntax check...")
-            val time1= measureTimeMillis {
-                programAst.checkIdentifiers()
-            }
-            //println(" time1: $time1")
-            val time2 = measureTimeMillis {
-                programAst.constantFold()
-            }
-            //println(" time2: $time2")
-            val time3 = measureTimeMillis {
-                programAst.reorderStatements()     // reorder statements and add type casts, to please the compiler later
-            }
-            //println(" time3: $time3")
-            val time4 = measureTimeMillis {
-                programAst.checkValid(compilerOptions)          // check if tree is valid
-            }
-            //println(" time4: $time4")
-
-            programAst.checkIdentifiers()
-            if(optimize) {
-                // optimize the parse tree
-                println("Optimizing...")
-                while (true) {
-                    // keep optimizing expressions and statements until no more steps remain
-                    val optsDone1 = programAst.simplifyExpressions()
-                    val optsDone2 = programAst.optimizeStatements(optimizeInlining)
-                    if (optsDone1 + optsDone2 == 0)
-                        break
-                }
-            }
-
-            programAst.checkValid(compilerOptions)          // check if final tree is valid
-            programAst.checkRecursion()         // check if there are recursive subroutine calls
-
-            // namespace.debugPrint()
-
-            // compile the syntax tree into stackvmProg form, and optimize that
-            val compiler = Compiler(programAst)
-            val intermediate = compiler.compile(compilerOptions)
-            if(optimize)
-                intermediate.optimize()
-
-            if(writeVmCode) {
-                val stackVmFilename = intermediate.name + ".vm.txt"
-                val stackvmFile = PrintStream(File(stackVmFilename), "utf-8")
-                intermediate.writeCode(stackvmFile)
-                stackvmFile.close()
-                println("StackVM program code written to '$stackVmFilename'")
-            }
-
-            if(writeAssembly) {
-                val zeropage = C64Zeropage(compilerOptions)
-                intermediate.allocateZeropage(zeropage)
-                val assembly = AsmGen(compilerOptions, intermediate, programAst.heap, zeropage).compileToAssembly(optimize)
-                assembly.assemble(compilerOptions)
-                programname = assembly.name
+    when(compilationTarget) {
+        "c64" -> {
+            with(CompilationTarget) {
+                name = "c64"
+                machine = C64MachineDefinition
+                encodeString = { str -> Petscii.encodePetscii(str, true) }
+                decodeString = { bytes -> Petscii.decodePetscii(bytes, true) }
+                asmGenerator = ::AsmGen
             }
         }
-        println("\nTotal compilation+assemble time: ${totalTime / 1000.0} sec.")
+        else -> {
+            System.err.println("invalid compilation target")
+            exitProcess(1)
+        }
+    }
 
-    } catch (px: ParsingFailedError) {
-        System.err.print("\u001b[91m")  // bright red
-        System.err.println(px.message)
-        System.err.print("\u001b[0m")  // reset
+    val outputPath = pathFrom(outputDir)
+    if(!outputPath.toFile().isDirectory) {
+        System.err.println("Output path doesn't exist")
         exitProcess(1)
-    } catch (ax: AstException) {
-        System.err.print("\u001b[91m")  // bright red
-        System.err.println(ax.toString())
-        System.err.print("\u001b[0m")  // reset
-        exitProcess(1)
-    } catch (x: Exception) {
-        print("\u001b[91m")  // bright red
-        println("\n* internal error *")
-        print("\u001b[0m")  // reset
-        System.out.flush()
-        throw x
-    } catch (x: NotImplementedError) {
-        print("\u001b[91m")  // bright red
-        println("\n* internal error: missing feature/code *")
-        print("\u001b[0m")  // reset
-        System.out.flush()
-        throw x
     }
 
-    if(launchAstVm) {
-        println("\nLaunching AST-based vm...")
-        val vm = AstVm(programAst)
-        vm.run()
-    }
+    if(watchMode && moduleFiles.size<=1) {
+        val watchservice = FileSystems.getDefault().newWatchService()
 
-    if(emulatorToStart.isNotEmpty()) {
-        println("\nStarting C-64 emulator $emulatorToStart...")
-        val cmdline = listOf(emulatorToStart, "-silent", "-moncommands", "$programname.vice-mon-list",
-                "-autostartprgmode", "1", "-autostart-warp", "-autostart", programname+".prg")
-        val process = ProcessBuilder(cmdline).inheritIO().start()
-        process.waitFor()
-    }
-}
+        while(true) {
+            val filepath = pathFrom(moduleFiles.single()).normalize()
+            println("Continuous watch mode active. Main module: $filepath")
 
-
-private fun determineCompilationOptions(program: Program): CompilationOptions {
-    val mainModule = program.modules.first()
-    val outputType = (mainModule.statements.singleOrNull { it is Directive && it.directive == "%output" }
-            as? Directive)?.args?.single()?.name?.toUpperCase()
-    val launcherType = (mainModule.statements.singleOrNull { it is Directive && it.directive == "%launcher" }
-            as? Directive)?.args?.single()?.name?.toUpperCase()
-    mainModule.loadAddress = (mainModule.statements.singleOrNull { it is Directive && it.directive == "%address" }
-            as? Directive)?.args?.single()?.int ?: 0
-    val zpoption: String? = (mainModule.statements.singleOrNull { it is Directive && it.directive == "%zeropage" }
-            as? Directive)?.args?.single()?.name?.toUpperCase()
-    val allOptions = program.modules.flatMap { it.statements }.filter { it is Directive && it.directive == "%option" }.flatMap { (it as Directive).args }.toSet()
-    val floatsEnabled = allOptions.any { it.name == "enable_floats" }
-    val zpType: ZeropageType =
-            if (zpoption == null)
-                if(floatsEnabled) ZeropageType.FLOATSAFE else ZeropageType.KERNALSAFE
-            else
-                try {
-                    ZeropageType.valueOf(zpoption)
-                } catch (x: IllegalArgumentException) {
-                    ZeropageType.KERNALSAFE
-                    // error will be printed by the astchecker
+            try {
+                val compilationResult = compileProgram(filepath, !dontOptimize, !dontWriteAssembly, outputDir=outputPath)
+                println("Imported files (now watching:)")
+                for (importedFile in compilationResult.importedFiles) {
+                    print("  ")
+                    println(importedFile)
+                    importedFile.parent.register(watchservice, StandardWatchEventKinds.ENTRY_MODIFY)
                 }
-    val zpReserved = mainModule.statements
-            .asSequence()
-            .filter { it is Directive && it.directive == "%zpreserved" }
-            .map { (it as Directive).args }
-            .map { it[0].int!!..it[1].int!! }
-            .toList()
+                println("[${LocalDateTime.now().withNano(0)}]  Waiting for file changes.")
+                val event = watchservice.take()
+                for(changed in event.pollEvents()) {
+                    val changedPath = changed.context() as Path
+                    println("  change detected: $changedPath")
+                }
+                event.reset()
+                println("\u001b[H\u001b[2J")      // clear the screen
+            } catch (x: Exception) {
+                throw x
+            }
+        }
 
-    return CompilationOptions(
-            if (outputType == null) OutputType.PRG else OutputType.valueOf(outputType),
-            if (launcherType == null) LauncherType.BASIC else LauncherType.valueOf(launcherType),
-            zpType, zpReserved, floatsEnabled
-    )
-}
+    } else {
+        for(filepathRaw in moduleFiles) {
+            val filepath = pathFrom(filepathRaw).normalize()
+            val compilationResult: CompilationResult
+            try {
+                compilationResult = compileProgram(filepath, !dontOptimize, !dontWriteAssembly, outputDir=outputPath)
+                if(!compilationResult.success)
+                    exitProcess(1)
+            } catch (x: ParsingFailedError) {
+                exitProcess(1)
+            } catch (x: AstException) {
+                exitProcess(1)
+            }
 
-private fun usage() {
-    System.err.println("Missing argument(s):")
-    System.err.println("    [-emu]          auto-start the 'x64' C-64 emulator after successful compilation")
-    System.err.println("    [-emu2]         auto-start the 'x64sc' C-64 emulator after successful compilation")
-    System.err.println("    [-writevm]      write intermediate vm code to a file as well")
-    System.err.println("    [-noasm]        don't create assembly code")
-    System.err.println("    [-vm]           launch the prog8 virtual machine instead of the compiler")
-    System.err.println("    [-avm]          launch the prog8 ast-based virtual machine after compilation")
-    System.err.println("    [-noopt]        don't perform any optimizations")
-    System.err.println("    [-nooptinline]  don't perform subroutine inlining optimizations")
-    System.err.println("    modulefile      main module file to compile")
-    exitProcess(1)
+            if (launchSimulator) {
+//                val c64 = razorvine.c64emu.C64Machine("C64 emulator launched from Prog8 compiler")
+//                c64.cpu.addBreakpoint(0xea31) { cpu, address ->
+//                    println("zz")
+//                    Cpu6502.BreakpointResultAction()
+//                }
+//                c64.start()
+                println("\nLaunching AST-based simulator...")
+                val vm = AstVm(compilationResult.programAst, compilationTarget)
+                vm.run()
+            }
+
+            if (startEmulator) {
+                if (compilationResult.programName.isEmpty())
+                    println("\nCan't start emulator because no program was assembled.")
+                else if(startEmulator) {
+                    for(emulator in listOf("x64sc", "x64")) {
+                        println("\nStarting C-64 emulator $emulator...")
+                        val cmdline = listOf(emulator, "-silent", "-moncommands", "${compilationResult.programName}.vice-mon-list",
+                                "-autostartprgmode", "1", "-autostart-warp", "-autostart", compilationResult.programName + ".prg")
+                        val processb = ProcessBuilder(cmdline).inheritIO()
+                        val process: Process
+                        try {
+                            process=processb.start()
+                        } catch(x: IOException) {
+                            continue  // try the next emulator executable
+                        }
+                        process.waitFor()
+                        break
+                    }
+                }
+            }
+        }
+    }
 }

compiler/src/prog8/StackVmMain.kt

@@ -1,46 +0,0 @@
-package prog8
-
-import prog8.stackvm.*
-import java.awt.EventQueue
-import javax.swing.Timer
-import kotlin.system.exitProcess
-
-fun main(args: Array<String>) {
-    stackVmMain(args)
-}
-
-fun stackVmMain(args: Array<String>) {
-    printSoftwareHeader("StackVM")
-
-    if(args.size != 1) {
-        System.err.println("requires one argument: name of stackvm sourcecode file")
-        exitProcess(1)
-    }
-
-    val program = Program.load(args.first())
-    val vm = StackVm(traceOutputFile = null)
-    val dialog = ScreenDialog()
-    vm.load(program, dialog.canvas)
-    EventQueue.invokeLater {
-        dialog.pack()
-        dialog.isVisible = true
-        dialog.start()
-
-        val programTimer = Timer(10) { a ->
-            try {
-                vm.step()
-            } catch(bp: VmBreakpointException) {
-                println("Breakpoint: execution halted. Press enter to resume.")
-                readLine()
-            } catch (tx: VmTerminationException) {
-                println("Execution halted: ${tx.message}")
-                (a.source as Timer).stop()
-            }
-        }
-
-        val irqTimer = Timer(1000/60) { a -> vm.irq(a.`when`) }
-
-        programTimer.start()
-        irqTimer.start()
-    }
-}

compiler/src/prog8/ast/AstIdentifiersChecker.kt

@@ -1,258 +0,0 @@
-package prog8.ast
-
-import prog8.functions.BuiltinFunctions
-
-/**
- * Checks the validity of all identifiers (no conflicts)
- * Also makes sure that subroutine's parameters also become local variable decls in the subroutine's scope.
- * Finally, it also makes sure the datatype of all Var decls and sub Return values is set correctly.
- */
-
-internal fun Program.checkIdentifiers() {
-    val checker = AstIdentifiersChecker(namespace)
-    checker.process(this)
-
-    if(modules.map {it.name}.toSet().size != modules.size) {
-        throw FatalAstException("modules should all be unique")
-    }
-
-    // add any anonymous variables for heap values that are used,
-    // and replace an iterable literalvalue by identifierref to new local variable
-    for (variable in checker.anonymousVariablesFromHeap.values) {
-        val scope = variable.first.definingScope()
-        scope.statements.add(variable.second)
-        val parent = variable.first.parent
-        when {
-            parent is Assignment && parent.value === variable.first -> {
-                val idref = IdentifierReference(listOf("$autoHeapValuePrefix${variable.first.heapId}"), variable.first.position)
-                idref.linkParents(parent)
-                parent.value = idref
-            }
-            parent is IFunctionCall -> {
-                val parameterPos = parent.arglist.indexOf(variable.first)
-                val idref = IdentifierReference(listOf("$autoHeapValuePrefix${variable.first.heapId}"), variable.first.position)
-                idref.linkParents(parent)
-                parent.arglist[parameterPos] = idref
-            }
-            parent is ForLoop -> {
-                val idref = IdentifierReference(listOf("$autoHeapValuePrefix${variable.first.heapId}"), variable.first.position)
-                idref.linkParents(parent)
-                parent.iterable = idref
-            }
-            else -> TODO("replace literalvalue by identifierref: $variable  (in $parent)")
-        }
-        variable.second.linkParents(scope as Node)
-    }
-
-    printErrors(checker.result(), name)
-}
-
-
-private class AstIdentifiersChecker(private val namespace: INameScope) : IAstProcessor {
-    private val checkResult: MutableList<AstException> = mutableListOf()
-
-    private var blocks: MutableMap<String, Block> = mutableMapOf()
-
-    internal fun result(): List<AstException> {
-        return checkResult
-    }
-
-    private fun nameError(name: String, position: Position, existing: IStatement) {
-        checkResult.add(NameError("name conflict '$name', also defined in ${existing.position.file} line ${existing.position.line}", position))
-    }
-
-    override fun process(module: Module) {
-        blocks.clear()  // blocks may be redefined within a different module
-        super.process(module)
-    }
-
-    override fun process(block: Block): IStatement {
-        val existing = blocks[block.name]
-        if(existing!=null)
-            nameError(block.name, block.position, existing)
-        else
-            blocks[block.name] = block
-
-        return super.process(block)
-    }
-
-    override fun process(functionCall: FunctionCall): IExpression {
-        if(functionCall.target.nameInSource.size==1 && functionCall.target.nameInSource[0]=="lsb") {
-            // lsb(...) is just an alias for type cast to ubyte, so replace with "... as ubyte"
-            val typecast = TypecastExpression(functionCall.arglist.single(), DataType.UBYTE, false, functionCall.position)
-            typecast.linkParents(functionCall.parent)
-            return super.process(typecast)
-        }
-        return super.process(functionCall)
-    }
-
-    override fun process(decl: VarDecl): IStatement {
-        // first, check if there are datatype errors on the vardecl
-        decl.datatypeErrors.forEach { checkResult.add(it) }
-
-        // now check the identifier
-        if(decl.name in BuiltinFunctions)
-            // the builtin functions can't be redefined
-            checkResult.add(NameError("builtin function cannot be redefined", decl.position))
-
-        val existing = namespace.lookup(listOf(decl.name), decl)
-        if (existing != null && existing !== decl)
-            nameError(decl.name, decl.position, existing)
-
-        return super.process(decl)
-    }
-
-    override fun process(subroutine: Subroutine): IStatement {
-        if(subroutine.name in BuiltinFunctions) {
-            // the builtin functions can't be redefined
-            checkResult.add(NameError("builtin function cannot be redefined", subroutine.position))
-        } else {
-            if (subroutine.parameters.any { it.name in BuiltinFunctions })
-                checkResult.add(NameError("builtin function name cannot be used as parameter", subroutine.position))
-
-            val existing = namespace.lookup(listOf(subroutine.name), subroutine)
-            if (existing != null && existing !== subroutine)
-                nameError(subroutine.name, subroutine.position, existing)
-
-            // check that there are no local variables, labels, or other subs that redefine the subroutine's parameters
-            val symbolsInSub = subroutine.allDefinedSymbols()
-            val namesInSub = symbolsInSub.map{ it.first }.toSet()
-            val paramNames = subroutine.parameters.map { it.name }.toSet()
-            val paramsToCheck = paramNames.intersect(namesInSub)
-            for(name in paramsToCheck) {
-                val labelOrVar = subroutine.getLabelOrVariable(name)
-                if(labelOrVar!=null && labelOrVar.position != subroutine.position)
-                    nameError(name, labelOrVar.position, subroutine)
-                val sub = subroutine.statements.singleOrNull { it is Subroutine && it.name==name}
-                if(sub!=null)
-                    nameError(name, sub.position, subroutine)
-            }
-
-            // inject subroutine params as local variables (if they're not there yet) (for non-kernel subroutines and non-asm parameters)
-            // NOTE:
-            // - numeric types BYTE and WORD and FLOAT are passed by value;
-            // - strings, arrays, matrices are passed by reference (their 16-bit address is passed as an uword parameter)
-            // - do NOT do this is the statement can be transformed into an asm subroutine later!
-            if(subroutine.asmAddress==null && !subroutine.canBeAsmSubroutine) {
-                if(subroutine.asmParameterRegisters.isEmpty()) {
-                    subroutine.parameters
-                            .filter { it.name !in namesInSub }
-                            .forEach {
-                                val vardecl = VarDecl(VarDeclType.VAR, it.type, false, null, it.name, null,
-                                        isArray = false, autoGenerated = true, position = subroutine.position)
-                                vardecl.linkParents(subroutine)
-                                subroutine.statements.add(0, vardecl)
-                            }
-                }
-            }
-        }
-        return super.process(subroutine)
-    }
-
-    override fun process(label: Label): IStatement {
-        if(label.name in BuiltinFunctions) {
-            // the builtin functions can't be redefined
-            checkResult.add(NameError("builtin function cannot be redefined", label.position))
-        } else {
-            val existing = namespace.lookup(listOf(label.name), label)
-            if (existing != null && existing !== label)
-                nameError(label.name, label.position, existing)
-        }
-        return super.process(label)
-    }
-
-    override fun process(forLoop: ForLoop): IStatement {
-        // If the for loop has a decltype, it means to declare the loopvar inside the loop body
-        // rather than reusing an already declared loopvar from an outer scope.
-        // For loops that loop over an interable variable (instead of a range of numbers) get an
-        // additional interation count variable in their scope.
-        if(forLoop.loopRegister!=null) {
-            if(forLoop.decltype!=null)
-                checkResult.add(SyntaxError("register loop variables have a fixed implicit datatype", forLoop.position))
-            if(forLoop.loopRegister == Register.X)
-                printWarning("writing to the X register is dangerous, because it's used as an internal pointer", forLoop.position)
-        } else if(forLoop.loopVar!=null) {
-            val varName = forLoop.loopVar.nameInSource.last()
-            if(forLoop.decltype!=null) {
-                val existing = if(forLoop.body.containsNoCodeNorVars()) null else forLoop.body.lookup(forLoop.loopVar.nameInSource, forLoop.body.statements.first())
-                if(existing==null) {
-                    // create the local scoped for loop variable itself
-                    val vardecl = VarDecl(VarDeclType.VAR, forLoop.decltype, forLoop.zeropage, null, varName, null,
-                            isArray = false, autoGenerated = true, position = forLoop.loopVar.position)
-                    vardecl.linkParents(forLoop.body)
-                    forLoop.body.statements.add(0, vardecl)
-                    forLoop.loopVar.parent = forLoop.body   // loopvar 'is defined in the body'
-                }
-
-            }
-
-            if(forLoop.iterable !is RangeExpr) {
-                val existing = if(forLoop.body.containsNoCodeNorVars()) null else forLoop.body.lookup(listOf(ForLoop.iteratorLoopcounterVarname), forLoop.body.statements.first())
-                if(existing==null) {
-                    // create loop iteration counter variable (without value, to avoid an assignment)
-                    val vardecl = VarDecl(VarDeclType.VAR, DataType.UBYTE, true, null, ForLoop.iteratorLoopcounterVarname, null,
-                            isArray = false, autoGenerated = true, position = forLoop.loopVar.position)
-                    vardecl.linkParents(forLoop.body)
-                    forLoop.body.statements.add(0, vardecl)
-                    forLoop.loopVar.parent = forLoop.body   // loopvar 'is defined in the body'
-                }
-            }
-        }
-        return super.process(forLoop)
-    }
-
-    override fun process(assignTarget: AssignTarget): AssignTarget {
-        if(assignTarget.register==Register.X)
-            printWarning("writing to the X register is dangerous, because it's used as an internal pointer", assignTarget.position)
-        return super.process(assignTarget)
-    }
-
-    override fun process(returnStmt: Return): IStatement {
-        if(returnStmt.values.isNotEmpty()) {
-            // possibly adjust any literal values returned, into the desired returning data type
-            val subroutine = returnStmt.definingSubroutine()!!
-            if(subroutine.returntypes.size!=returnStmt.values.size)
-                return returnStmt  // mismatch in number of return values, error will be printed later.
-            val newValues = mutableListOf<IExpression>()
-            for(returnvalue in returnStmt.values.zip(subroutine.returntypes)) {
-                val lval = returnvalue.first as? LiteralValue
-                if(lval!=null) {
-                    val adjusted = lval.intoDatatype(returnvalue.second)
-                    if(adjusted!=null && adjusted !== lval)
-                        newValues.add(adjusted)
-                    else
-                        newValues.add(lval)
-                }
-                else
-                    newValues.add(returnvalue.first)
-            }
-            returnStmt.values = newValues
-        }
-        return super.process(returnStmt)
-    }
-
-
-    internal val anonymousVariablesFromHeap = mutableMapOf<String, Pair<LiteralValue, VarDecl>>()
-
-
-    override fun process(literalValue: LiteralValue): LiteralValue {
-        if(literalValue.heapId!=null && literalValue.parent !is VarDecl) {
-            // a literal value that's not declared as a variable, which refers to something on the heap.
-            // we need to introduce an auto-generated variable for this to be able to refer to the value!
-            val variable = VarDecl(VarDeclType.VAR, literalValue.type, false, null, "$autoHeapValuePrefix${literalValue.heapId}", literalValue,
-                    isArray = false, autoGenerated = false, position = literalValue.position)
-            anonymousVariablesFromHeap[variable.name] = Pair(literalValue, variable)
-        }
-        return super.process(literalValue)
-    }
-
-    override fun process(addressOf: AddressOf): IExpression {
-        // register the scoped name of the referenced identifier
-        val variable= addressOf.identifier.targetVarDecl(namespace) ?: return addressOf
-        addressOf.scopedname = variable.scopedname
-        return super.process(addressOf)
-    }
-
-}
-
-internal const val autoHeapValuePrefix = "auto_heap_value_"

compiler/src/prog8/ast/AstRecursionChecker.kt

@@ -1,120 +0,0 @@
-package prog8.ast
-
-/**
- * Checks for the occurrence of recursive subroutine calls
- */
-
-internal fun Program.checkRecursion() {
-    val checker = AstRecursionChecker(namespace)
-    checker.process(this)
-    printErrors(checker.result(), name)
-}
-
-
-private class DirectedGraph<VT> {
-    private val graph = mutableMapOf<VT, MutableSet<VT>>()
-    private var uniqueVertices = mutableSetOf<VT>()
-    val numVertices : Int
-        get() = uniqueVertices.size
-
-    fun add(from: VT, to: VT) {
-        var targets = graph[from]
-        if(targets==null) {
-            targets = mutableSetOf()
-            graph[from] = targets
-        }
-        targets.add(to)
-        uniqueVertices.add(from)
-        uniqueVertices.add(to)
-    }
-
-    fun print() {
-        println("#vertices: $numVertices")
-        graph.forEach { (from, to) ->
-            println("$from   CALLS:")
-            to.forEach { println("   $it") }
-        }
-        val cycle = checkForCycle()
-        if(cycle.isNotEmpty()) {
-            println("CYCLIC!  $cycle")
-        }
-    }
-
-    fun checkForCycle(): MutableList<VT> {
-        val visited = uniqueVertices.associateWith { false }.toMutableMap()
-        val recStack = uniqueVertices.associateWith { false }.toMutableMap()
-        val cycle = mutableListOf<VT>()
-        for(node in uniqueVertices) {
-            if(isCyclicUntil(node, visited, recStack, cycle))
-                return cycle
-        }
-        return mutableListOf()
-    }
-
-    private fun isCyclicUntil(node: VT,
-                              visited: MutableMap<VT, Boolean>,
-                              recStack: MutableMap<VT, Boolean>,
-                              cycleNodes: MutableList<VT>): Boolean {
-
-        if(recStack[node]==true) return true
-        if(visited[node]==true) return false
-
-        // mark current node as visited and add to recursion stack
-        visited[node] = true
-        recStack[node] = true
-
-        // recurse for all neighbours
-        val neighbors = graph[node]
-        if(neighbors!=null) {
-            for (neighbour in neighbors) {
-                if (isCyclicUntil(neighbour, visited, recStack, cycleNodes)) {
-                    cycleNodes.add(node)
-                    return true
-                }
-            }
-        }
-
-        // pop node from recursion stack
-        recStack[node] = false
-        return false
-    }
-}
-
-
-private class AstRecursionChecker(private val namespace: INameScope) : IAstProcessor {
-    private val callGraph = DirectedGraph<INameScope>()
-
-    internal fun result(): List<AstException> {
-        val cycle = callGraph.checkForCycle()
-        if(cycle.isEmpty())
-            return emptyList()
-        val chain = cycle.joinToString(" <-- ") { "${it.name} at ${it.position}" }
-        return listOf(AstException("Program contains recursive subroutine calls, this is not supported. Recursive chain:\n (a subroutine call in) $chain"))
-    }
-
-    override fun process(functionCallStatement: FunctionCallStatement): IStatement {
-        val scope = functionCallStatement.definingScope()
-        val targetStatement = functionCallStatement.target.targetStatement(namespace)
-        if(targetStatement!=null) {
-            val targetScope = when (targetStatement) {
-                is Subroutine -> targetStatement
-                else -> targetStatement.definingScope()
-            }
-            callGraph.add(scope, targetScope)
-        }
-        return super.process(functionCallStatement)
-    }
-
-    override fun process(functionCall: FunctionCall): IExpression {
-        val scope = functionCall.definingScope()
-        val targetStatement = functionCall.target.targetStatement(namespace)
-        if(targetStatement!=null) {
-            val targetScope = when (targetStatement) {
-                is Subroutine -> targetStatement
-                else -> targetStatement.definingScope()
-            }
-            callGraph.add(scope, targetScope)
-        }
-        return super.process(functionCall)
-    }
-}

compiler/src/prog8/ast/AstToSourceCode.kt

@@ -0,0 +1,445 @@
+package prog8.ast
+
+import prog8.ast.antlr.escape
+import prog8.ast.base.DataType
+import prog8.ast.base.NumericDatatypes
+import prog8.ast.base.VarDeclType
+import prog8.ast.expressions.*
+import prog8.ast.processing.IAstVisitor
+import prog8.ast.statements.*
+import prog8.compiler.toHex
+
+class AstToSourceCode(val output: (text: String) -> Unit, val program: Program): IAstVisitor {
+    private var scopelevel = 0
+
+    private fun indent(s: String) = "    ".repeat(scopelevel) + s
+    private fun outputln(text: String) = output(text + "\n")
+    private fun outputlni(s: Any) = outputln(indent(s.toString()))
+    private fun outputi(s: Any) = output(indent(s.toString()))
+
+    override fun visit(program: Program) {
+        outputln("============= PROGRAM ${program.name} (FROM AST) ===============")
+        super.visit(program)
+        outputln("============= END PROGRAM ${program.name} (FROM AST) ===========")
+    }
+
+    override fun visit(module: Module) {
+        if(!module.isLibraryModule) {
+            outputln("; ----------- module: ${module.name} -----------")
+            super.visit(module)
+        }
+        else outputln("; library module skipped: ${module.name}")
+    }
+
+    override fun visit(block: Block) {
+        val addr = if(block.address!=null) block.address.toHex() else ""
+        outputln("~ ${block.name} $addr {")
+        scopelevel++
+        for(stmt in block.statements) {
+            outputi("")
+            stmt.accept(this)
+            output("\n")
+        }
+        scopelevel--
+        outputln("}\n")
+    }
+
+    override fun visit(expr: PrefixExpression) {
+        if(expr.operator.any { it.isLetter() })
+            output(" ${expr.operator} ")
+        else
+            output(expr.operator)
+        expr.expression.accept(this)
+    }
+
+    override fun visit(expr: BinaryExpression) {
+        expr.left.accept(this)
+        if(expr.operator.any { it.isLetter() })
+            output(" ${expr.operator} ")
+        else
+            output(expr.operator)
+        expr.right.accept(this)
+    }
+
+    override fun visit(directive: Directive) {
+        output("${directive.directive} ")
+        for(arg in directive.args) {
+            when {
+                arg.int!=null -> output(arg.int.toString())
+                arg.name!=null -> output(arg.name)
+                arg.str!=null -> output("\"${arg.str}\"")
+            }
+            if(arg!==directive.args.last())
+                output(",")
+        }
+        output("\n")
+    }
+
+    private fun datatypeString(dt: DataType): String {
+        return when(dt) {
+            in NumericDatatypes -> dt.toString().toLowerCase()
+            DataType.STR -> dt.toString().toLowerCase()
+            DataType.ARRAY_UB -> "ubyte["
+            DataType.ARRAY_B -> "byte["
+            DataType.ARRAY_UW -> "uword["
+            DataType.ARRAY_W -> "word["
+            DataType.ARRAY_F -> "float["
+            DataType.STRUCT -> ""       // the name of the struct is enough
+            else -> "?????2"
+        }
+    }
+
+    override fun visit(structDecl: StructDecl) {
+        outputln("struct ${structDecl.name} {")
+        scopelevel++
+        for(decl in structDecl.statements) {
+            outputi("")
+            decl.accept(this)
+            output("\n")
+        }
+        scopelevel--
+        outputlni("}")
+    }
+
+    override fun visit(decl: VarDecl) {
+        when(decl.type) {
+            VarDeclType.VAR -> {}
+            VarDeclType.CONST -> output("const ")
+            VarDeclType.MEMORY -> output("&")
+        }
+        output(decl.struct?.name ?: "")
+        output(datatypeString(decl.datatype))
+        if(decl.arraysize!=null) {
+            decl.arraysize!!.index.accept(this)
+        }
+        if(decl.isArray)
+            output("]")
+
+        if(decl.zeropage == ZeropageWish.REQUIRE_ZEROPAGE || decl.zeropage==ZeropageWish.PREFER_ZEROPAGE)
+            output(" @zp")
+        output(" ${decl.name} ")
+        if(decl.value!=null) {
+            output("= ")
+            decl.value?.accept(this)
+        }
+    }
+
+    override fun visit(subroutine: Subroutine) {
+        output("\n")
+        if(subroutine.isAsmSubroutine) {
+            outputi("asmsub ${subroutine.name} (")
+            for(param in subroutine.parameters.zip(subroutine.asmParameterRegisters)) {
+                val reg =
+                        when {
+                            param.second.stack -> "stack"
+                            param.second.registerOrPair!=null -> param.second.registerOrPair.toString()
+                            param.second.statusflag!=null -> param.second.statusflag.toString()
+                            else -> "?????1"
+                        }
+                output("${datatypeString(param.first.type)} ${param.first.name} @$reg")
+                if(param.first!==subroutine.parameters.last())
+                    output(", ")
+            }
+        }
+        else {
+            outputi("sub ${subroutine.name} (")
+            for(param in subroutine.parameters) {
+                output("${datatypeString(param.type)} ${param.name}")
+                if(param!==subroutine.parameters.last())
+                    output(", ")
+            }
+        }
+        output(") ")
+        if(subroutine.asmClobbers.isNotEmpty()) {
+            output("-> clobbers (")
+            val regs = subroutine.asmClobbers.toList().sorted()
+            for(r in regs) {
+                output(r.toString())
+                if(r!==regs.last())
+                    output(",")
+            }
+            output(") ")
+        }
+        if(subroutine.returntypes.any()) {
+            val rt = subroutine.returntypes.single()
+            output("-> ${datatypeString(rt)} ")
+        }
+        if(subroutine.asmAddress!=null)
+            outputln("= ${subroutine.asmAddress.toHex()}")
+        else {
+            outputln("{ ")
+            scopelevel++
+            outputStatements(subroutine.statements)
+            scopelevel--
+            outputi("}")
+        }
+    }
+
+    private fun outputStatements(statements: List<Statement>) {
+        for(stmt in statements) {
+            if(stmt is VarDecl && stmt.autogeneratedDontRemove)
+                continue    // skip autogenerated decls (to avoid generating a newline)
+            outputi("")
+            stmt.accept(this)
+            output("\n")
+        }
+    }
+
+    override fun visit(functionCall: FunctionCall) {
+        printout(functionCall as IFunctionCall)
+    }
+
+    override fun visit(functionCallStatement: FunctionCallStatement) {
+        printout(functionCallStatement as IFunctionCall)
+    }
+
+    private fun printout(call: IFunctionCall) {
+        call.target.accept(this)
+        output("(")
+        for(arg in call.args) {
+            arg.accept(this)
+            if(arg!==call.args.last())
+                output(", ")
+        }
+        output(")")
+    }
+
+    override fun visit(identifier: IdentifierReference) {
+        output(identifier.nameInSource.joinToString("."))
+    }
+
+    override fun visit(jump: Jump) {
+        output("goto ")
+        when {
+            jump.address!=null -> output(jump.address.toHex())
+            jump.generatedLabel!=null -> output(jump.generatedLabel)
+            jump.identifier!=null -> jump.identifier.accept(this)
+        }
+    }
+
+    override fun visit(ifStatement: IfStatement) {
+        output("if ")
+        ifStatement.condition.accept(this)
+        output(" ")
+        ifStatement.truepart.accept(this)
+        if(ifStatement.elsepart.statements.isNotEmpty()) {
+            output(" else ")
+            ifStatement.elsepart.accept(this)
+        }
+    }
+
+    override fun visit(branchStatement: BranchStatement) {
+        output("if_${branchStatement.condition.toString().toLowerCase()} ")
+        branchStatement.truepart.accept(this)
+        if(branchStatement.elsepart.statements.isNotEmpty()) {
+            output(" else ")
+            branchStatement.elsepart.accept(this)
+        }
+    }
+
+    override fun visit(range: RangeExpr) {
+        range.from.accept(this)
+        output(" to ")
+        range.to.accept(this)
+        output(" step ")
+        range.step.accept(this)
+        output(" ")
+    }
+
+    override fun visit(label: Label) {
+        output("\n")
+        output("${label.name}:")
+    }
+
+    override fun visit(numLiteral: NumericLiteralValue) {
+        output(numLiteral.number.toString())
+    }
+
+    override fun visit(string: StringLiteralValue) {
+        output("\"${escape(string.value)}\"")
+    }
+
+    override fun visit(array: ArrayLiteralValue) {
+        outputListMembers(array.value.asSequence(), '[', ']')
+    }
+
+    private fun outputListMembers(array: Sequence<Expression>, openchar: Char, closechar: Char) {
+        var counter = 0
+        output(openchar.toString())
+        scopelevel++
+        for (v in array) {
+            v.accept(this)
+            if (v !== array.last())
+                output(", ")
+            counter++
+            if (counter > 16) {
+                outputln("")
+                outputi("")
+                counter = 0
+            }
+        }
+        scopelevel--
+        output(closechar.toString())
+    }
+
+    override fun visit(assignment: Assignment) {
+        if(assignment is VariableInitializationAssignment) {
+            val targetVar = assignment.target.identifier?.targetVarDecl(program.namespace)
+            if(targetVar?.struct != null) {
+                // skip STRUCT init assignments
+                return
+            }
+        }
+
+        assignment.target.accept(this)
+        if (assignment.aug_op != null)
+            output(" ${assignment.aug_op} ")
+        else
+            output(" = ")
+        assignment.value.accept(this)
+    }
+
+    override fun visit(postIncrDecr: PostIncrDecr) {
+        postIncrDecr.target.accept(this)
+        output(postIncrDecr.operator)
+    }
+
+    override fun visit(contStmt: Continue) {
+        output("continue")
+    }
+
+    override fun visit(breakStmt: Break) {
+        output("break")
+    }
+
+    override fun visit(forLoop: ForLoop) {
+        output("for ")
+        if(forLoop.loopRegister!=null)
+            output(forLoop.loopRegister.toString())
+        else
+            forLoop.loopVar!!.accept(this)
+        output(" in ")
+        forLoop.iterable.accept(this)
+        output(" ")
+        forLoop.body.accept(this)
+    }
+
+    override fun visit(whileLoop: WhileLoop) {
+        output("while ")
+        whileLoop.condition.accept(this)
+        output(" ")
+        whileLoop.body.accept(this)
+    }
+
+    override fun visit(repeatLoop: RepeatLoop) {
+        output("repeat ")
+        repeatLoop.body.accept(this)
+        output(" until ")
+        repeatLoop.untilCondition.accept(this)
+    }
+
+    override fun visit(returnStmt: Return) {
+        output("return ")
+        returnStmt.value?.accept(this)
+    }
+
+    override fun visit(arrayIndexedExpression: ArrayIndexedExpression) {
+        arrayIndexedExpression.identifier.accept(this)
+        output("[")
+        arrayIndexedExpression.arrayspec.index.accept(this)
+        output("]")
+    }
+
+    override fun visit(assignTarget: AssignTarget) {
+        if(assignTarget.register!=null)
+            output(assignTarget.register.toString())
+        else {
+            assignTarget.memoryAddress?.accept(this)
+            assignTarget.identifier?.accept(this)
+        }
+        assignTarget.arrayindexed?.accept(this)
+    }
+
+    override fun visit(scope: AnonymousScope) {
+        outputln("{")
+        scopelevel++
+        outputStatements(scope.statements)
+        scopelevel--
+        outputi("}")
+    }
+
+    override fun visit(typecast: TypecastExpression) {
+        output("(")
+        typecast.expression.accept(this)
+        output(" as ${datatypeString(typecast.type)}) ")
+    }
+
+    override fun visit(memread: DirectMemoryRead) {
+        output("@(")
+        memread.addressExpression.accept(this)
+        output(")")
+    }
+
+    override fun visit(memwrite: DirectMemoryWrite) {
+        output("@(")
+        memwrite.addressExpression.accept(this)
+        output(")")
+    }
+
+    override fun visit(addressOf: AddressOf) {
+        output("&")
+        addressOf.identifier.accept(this)
+    }
+
+    override fun visit(inlineAssembly: InlineAssembly) {
+        outputlni("%asm {{")
+        outputln(inlineAssembly.assembly)
+        outputlni("}}")
+    }
+
+    override fun visit(registerExpr: RegisterExpr) {
+        output(registerExpr.register.toString())
+    }
+
+    override fun visit(builtinFunctionStatementPlaceholder: BuiltinFunctionStatementPlaceholder) {
+        output(builtinFunctionStatementPlaceholder.name)
+    }
+
+    override fun visit(whenStatement: WhenStatement) {
+        output("when ")
+        whenStatement.condition.accept(this)
+        outputln(" {")
+        scopelevel++
+        whenStatement.choices.forEach { it.accept(this) }
+        scopelevel--
+        outputlni("}")
+    }
+
+    override fun visit(whenChoice: WhenChoice) {
+        val choiceValues = whenChoice.values
+        if(choiceValues==null)
+            outputi("else -> ")
+        else {
+            outputi("")
+            for(value in choiceValues) {
+                value.accept(this)
+                if(value !== choiceValues.last())
+                    output(",")
+            }
+            output(" -> ")
+        }
+        if(whenChoice.statements.statements.size==1)
+            whenChoice.statements.statements.single().accept(this)
+        else
+            whenChoice.statements.accept(this)
+        outputln("")
+    }
+
+    override fun visit(structLv: StructLiteralValue) {
+        outputListMembers(structLv.values.asSequence(), '{', '}')
+    }
+
+    override fun visit(nopStatement: NopStatement) {
+        output("; NOP @ ${nopStatement.position}  $nopStatement")
+    }
+}

compiler/src/prog8/ast/AstToplevel.kt

@@ -0,0 +1,264 @@
+package prog8.ast
+
+import prog8.ast.base.*
+import prog8.ast.expressions.Expression
+import prog8.ast.expressions.IdentifierReference
+import prog8.ast.statements.*
+import prog8.functions.BuiltinFunctions
+import java.nio.file.Path
+
+
+interface Node {
+    val position: Position
+    var parent: Node             // will be linked correctly later (late init)
+    fun linkParents(parent: Node)
+
+    fun definingModule(): Module {
+        if(this is Module)
+            return this
+        return findParentNode<Module>(this)!!
+    }
+
+    fun definingSubroutine(): Subroutine?  = findParentNode<Subroutine>(this)
+
+    fun definingScope(): INameScope {
+        val scope = findParentNode<INameScope>(this)
+        if(scope!=null) {
+            return scope
+        }
+        if(this is Label && this.name.startsWith("builtin::")) {
+            return BuiltinFunctionScopePlaceholder
+        }
+        if(this is GlobalNamespace)
+            return this
+        throw FatalAstException("scope missing from $this")
+    }
+}
+
+interface IFunctionCall {
+    var target: IdentifierReference
+    var args: MutableList<Expression>
+}
+
+interface INameScope {
+    val name: String
+    val position: Position
+    val statements: MutableList<Statement>
+    val parent: Node
+
+    fun linkParents(parent: Node)
+
+    fun subScopes(): Map<String, INameScope> {
+        val subscopes = mutableMapOf<String, INameScope>()
+        for(stmt in statements) {
+            when(stmt) {
+                // NOTE: if other nodes are introduced that are a scope, or contain subscopes, they must be added here!
+                is ForLoop -> subscopes[stmt.body.name] = stmt.body
+                is RepeatLoop -> subscopes[stmt.body.name] = stmt.body
+                is WhileLoop -> subscopes[stmt.body.name] = stmt.body
+                is BranchStatement -> {
+                    subscopes[stmt.truepart.name] = stmt.truepart
+                    if(stmt.elsepart.containsCodeOrVars())
+                        subscopes[stmt.elsepart.name] = stmt.elsepart
+                }
+                is IfStatement -> {
+                    subscopes[stmt.truepart.name] = stmt.truepart
+                    if(stmt.elsepart.containsCodeOrVars())
+                        subscopes[stmt.elsepart.name] = stmt.elsepart
+                }
+                is WhenStatement -> {
+                    stmt.choices.forEach { subscopes[it.statements.name] = it.statements }
+                }
+                is INameScope -> subscopes[stmt.name] = stmt
+                else -> {}
+            }
+        }
+        return subscopes
+    }
+
+    fun getLabelOrVariable(name: String): Statement? {
+        // this is called A LOT and could perhaps be optimized a bit more,
+        // but adding a memoization cache didn't make much of a practical runtime difference
+        for (stmt in statements) {
+            if (stmt is VarDecl && stmt.name==name) return stmt
+            if (stmt is Label && stmt.name==name) return stmt
+            if (stmt is AnonymousScope) {
+                val sub = stmt.getLabelOrVariable(name)
+                if(sub!=null)
+                    return sub
+            }
+        }
+        return null
+    }
+
+    fun allDefinedSymbols(): List<Pair<String, Statement>>  {
+        return statements.mapNotNull {
+            when (it) {
+                is Label -> it.name to it
+                is VarDecl -> it.name to it
+                is Subroutine -> it.name to it
+                is Block -> it.name to it
+                else -> null
+            }
+        }
+    }
+
+    fun lookup(scopedName: List<String>, localContext: Node) : Statement? {
+        if(scopedName.size>1) {
+            // a scoped name can a) refer to a member of a struct, or b) refer to a name in another module.
+            // try the struct first.
+            val thing = lookup(scopedName.dropLast(1), localContext) as? VarDecl
+            val struct = thing?.struct
+            if (struct != null) {
+                if(struct.statements.any { (it as VarDecl).name == scopedName.last()}) {
+                    // return ref to the mangled name variable
+                    val mangled = mangledStructMemberName(thing.name, scopedName.last())
+                    return thing.definingScope().getLabelOrVariable(mangled)
+                }
+            }
+
+            // it's a qualified name, look it up from the root of the module's namespace (consider all modules in the program)
+            for(module in localContext.definingModule().program.modules) {
+                var scope: INameScope? = module
+                for(name in scopedName.dropLast(1)) {
+                    scope = scope?.subScopes()?.get(name)
+                    if(scope==null)
+                        break
+                }
+                if(scope!=null) {
+                    val result = scope.getLabelOrVariable(scopedName.last())
+                    if(result!=null)
+                        return result
+                    return scope.subScopes()[scopedName.last()] as Statement?
+                }
+            }
+            return null
+        } else {
+            // unqualified name, find the scope the localContext is in, look in that first
+            var statementScope = localContext
+            while(statementScope !is ParentSentinel) {
+                val localScope = statementScope.definingScope()
+                val result = localScope.getLabelOrVariable(scopedName[0])
+                if (result != null)
+                    return result
+                val subscope = localScope.subScopes()[scopedName[0]] as Statement?
+                if (subscope != null)
+                    return subscope
+                // not found in this scope, look one higher up
+                statementScope = statementScope.parent
+            }
+            return null
+        }
+    }
+
+    fun containsCodeOrVars() = statements.any { it !is Directive || it.directive == "%asminclude" || it.directive == "%asm"}
+    fun containsNoCodeNorVars() = !containsCodeOrVars()
+
+    fun remove(stmt: Statement) {
+        if(!statements.remove(stmt))
+            throw FatalAstException("stmt to remove wasn't found in scope")
+    }
+}
+
+interface IAssignable {
+    // just a tag for now
+}
+
+
+/*********** Everything starts from here, the Program; zero or more modules *************/
+
+class Program(val name: String, val modules: MutableList<Module>) {
+    val namespace = GlobalNamespace(modules)
+
+    val definedLoadAddress: Int
+        get() = modules.first().loadAddress
+
+    var actualLoadAddress: Int = 0
+
+    fun entrypoint(): Subroutine? {
+        val mainBlocks = allBlocks().filter { it.name=="main" }
+        if(mainBlocks.size > 1)
+            throw FatalAstException("more than one 'main' block")
+        return if(mainBlocks.isEmpty()) {
+            null
+        } else {
+            mainBlocks[0].subScopes()["start"] as Subroutine?
+        }
+    }
+
+    fun allBlocks(): List<Block> = modules.flatMap { it.statements.filterIsInstance<Block>() }
+}
+
+class Module(override val name: String,
+             override var statements: MutableList<Statement>,
+             override val position: Position,
+             val isLibraryModule: Boolean,
+             val source: Path) : Node, INameScope {
+    override lateinit var parent: Node
+    lateinit var program: Program
+    val importedBy = mutableListOf<Module>()
+    val imports = mutableSetOf<Module>()
+
+    var loadAddress: Int = 0        // can be set with the %address directive
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        statements.forEach {it.linkParents(this)}
+    }
+
+    override fun definingScope(): INameScope = program.namespace
+
+    override fun toString() = "Module(name=$name, pos=$position, lib=$isLibraryModule)"
+}
+
+class GlobalNamespace(val modules: List<Module>): Node, INameScope {
+    override val name = "<<<global>>>"
+    override val position = Position("<<<global>>>", 0, 0, 0)
+    override val statements = mutableListOf<Statement>()
+    override var parent: Node = ParentSentinel
+
+    override fun linkParents(parent: Node) {
+        modules.forEach { it.linkParents(this) }
+    }
+
+    override fun lookup(scopedName: List<String>, localContext: Node): Statement? {
+        if (scopedName.size == 1 && scopedName[0] in BuiltinFunctions) {
+            // builtin functions always exist, return a dummy localContext for them
+            val builtinPlaceholder = Label("builtin::${scopedName.last()}", localContext.position)
+            builtinPlaceholder.parent = ParentSentinel
+            return builtinPlaceholder
+        }
+
+        if(scopedName.size>1) {
+            // a scoped name can a) refer to a member of a struct, or b) refer to a name in another module.
+            // try the struct first.
+            val thing = lookup(scopedName.dropLast(1), localContext) as? VarDecl
+            val struct = thing?.struct
+            if (struct != null) {
+                if(struct.statements.any { (it as VarDecl).name == scopedName.last()}) {
+                    // return ref to the mangled name variable
+                    val mangled = mangledStructMemberName(thing.name, scopedName.last())
+                    return thing.definingScope().getLabelOrVariable(mangled)
+                }
+            }
+        }
+        // lookup something from the module.
+        return when (val stmt = localContext.definingModule().lookup(scopedName, localContext)) {
+            is Label, is VarDecl, is Block, is Subroutine -> stmt
+            null -> null
+            else -> throw NameError("wrong identifier target: $stmt", stmt.position)
+        }
+    }
+}
+
+object BuiltinFunctionScopePlaceholder : INameScope {
+    override val name = "<<builtin-functions-scope-placeholder>>"
+    override val position = Position("<<placeholder>>", 0, 0, 0)
+    override var statements = mutableListOf<Statement>()
+    override var parent: Node = ParentSentinel
+    override fun linkParents(parent: Node) {}
+}
+
+
+// prefix for struct member variables
+internal fun mangledStructMemberName(varName: String, memberName: String) = "prog8struct_${varName}_$memberName"

compiler/src/prog8/ast/StmtReorderer.kt

@@ -1,430 +0,0 @@
-package prog8.ast
-
-import prog8.functions.BuiltinFunctions
-
-internal fun Program.reorderStatements() {
-    val initvalueCreator = VarInitValueAndAddressOfCreator(namespace)
-    initvalueCreator.process(this)
-
-    val checker = StatementReorderer(this)
-    checker.process(this)
-}
-
-internal const val initvarsSubName="prog8_init_vars"    // the name of the subroutine that should be called for every block to initialize its variables
-
-
-private class StatementReorderer(private val program: Program): IAstProcessor {
-    // Reorders the statements in a way the compiler needs.
-    // - 'main' block must be the very first statement UNLESS it has an address set.
-    // - blocks are ordered by address, where blocks without address are put at the end.
-    // - in every scope:
-    //      -- the directives '%output', '%launcher', '%zeropage', '%zpreserved', '%address' and '%option' will come first.
-    //      -- all vardecls then follow.
-    //      -- the remaining statements then follow in their original order.
-    //
-    // - the 'start' subroutine in the 'main' block will be moved to the top immediately following the directives.
-    // - all other subroutines will be moved to the end of their block.
-    //
-    // Also, makes sure any value assignments get the proper type casts if needed to cast them into the target variable's type.
-    // (this includes function call arguments)
-
-    private val directivesToMove = setOf("%output", "%launcher", "%zeropage", "%zpreserved", "%address", "%option")
-
-    override fun process(module: Module) {
-        super.process(module)
-
-        val (blocks, other) = module.statements.partition { it is Block }
-        module.statements = other.asSequence().plus(blocks.sortedBy { (it as Block).address ?: Int.MAX_VALUE }).toMutableList()
-
-        // make sure user-defined blocks come BEFORE library blocks, and move the "main" block to the top of everything
-        val nonLibraryBlocks = module.statements.withIndex()
-                .filter { it.value is Block && !(it.value as Block).isInLibrary }
-                .map { it.index to it.value }
-                .reversed()
-        for(nonLibBlock in nonLibraryBlocks)
-            module.statements.removeAt(nonLibBlock.first)
-        for(nonLibBlock in nonLibraryBlocks)
-            module.statements.add(0, nonLibBlock.second)
-        val mainBlock = module.statements.singleOrNull { it is Block && it.name=="main" }
-        if(mainBlock!=null && (mainBlock as Block).address==null) {
-            module.remove(mainBlock)
-            module.statements.add(0, mainBlock)
-        }
-
-        val varDecls = module.statements.filterIsInstance<VarDecl>()
-        module.statements.removeAll(varDecls)
-        module.statements.addAll(0, varDecls)
-
-        val directives = module.statements.filter {it is Directive && it.directive in directivesToMove}
-        module.statements.removeAll(directives)
-        module.statements.addAll(0, directives)
-
-        sortConstantAssignments(module.statements)
-    }
-
-    override fun process(block: Block): IStatement {
-
-        val subroutines = block.statements.filterIsInstance<Subroutine>()
-        var numSubroutinesAtEnd = 0
-        // move all subroutines to the end of the block
-        for (subroutine in subroutines) {
-            if(subroutine.name!="start" || block.name!="main") {
-                block.remove(subroutine)
-                block.statements.add(subroutine)
-            }
-            numSubroutinesAtEnd++
-        }
-        // move the "start" subroutine to the top
-        if(block.name=="main") {
-            block.statements.singleOrNull { it is Subroutine && it.name == "start" } ?.let {
-                block.remove(it)
-                block.statements.add(0, it)
-                numSubroutinesAtEnd--
-            }
-        }
-
-        // make sure there is a 'return' in front of the first subroutine
-        // (if it isn't the first statement in the block itself, and isn't the program's entrypoint)
-        if(numSubroutinesAtEnd>0 && block.statements.size > (numSubroutinesAtEnd+1)) {
-            val firstSub = block.statements[block.statements.size - numSubroutinesAtEnd] as Subroutine
-            if(firstSub.name != "start" && block.name != "main") {
-                val stmtBeforeFirstSub = block.statements[block.statements.size - numSubroutinesAtEnd - 1]
-                if (stmtBeforeFirstSub !is Return
-                        && stmtBeforeFirstSub !is Jump
-                        && stmtBeforeFirstSub !is Subroutine
-                        && stmtBeforeFirstSub !is BuiltinFunctionStatementPlaceholder) {
-                    val ret = Return(emptyList(), stmtBeforeFirstSub.position)
-                    ret.linkParents(block)
-                    block.statements.add(block.statements.size - numSubroutinesAtEnd, ret)
-                }
-            }
-        }
-
-        val varDecls = block.statements.filterIsInstance<VarDecl>()
-        block.statements.removeAll(varDecls)
-        block.statements.addAll(0, varDecls)
-        val directives = block.statements.filter {it is Directive && it.directive in directivesToMove}
-        block.statements.removeAll(directives)
-        block.statements.addAll(0, directives)
-        block.linkParents(block.parent)
-
-        sortConstantAssignments(block.statements)
-
-        // create subroutine that initializes the block's variables (if any)
-        val varInits = block.statements.withIndex().filter { it.value is VariableInitializationAssignment }
-        if(varInits.isNotEmpty()) {
-            val statements = varInits.map{it.value}.toMutableList()
-            val varInitSub = Subroutine(initvarsSubName, emptyList(), emptyList(), emptyList(), emptyList(),
-                    emptySet(), null, false, statements, block.position)
-            varInitSub.keepAlways = true
-            varInitSub.linkParents(block)
-            block.statements.add(varInitSub)
-
-            // remove the varinits from the block's statements
-            for(index in varInits.map{it.index}.reversed())
-                block.statements.removeAt(index)
-        }
-
-        return super.process(block)
-    }
-
-    override fun process(subroutine: Subroutine): IStatement {
-        super.process(subroutine)
-
-        sortConstantAssignments(subroutine.statements)
-
-        val varDecls = subroutine.statements.filterIsInstance<VarDecl>()
-        subroutine.statements.removeAll(varDecls)
-        subroutine.statements.addAll(0, varDecls)
-        val directives = subroutine.statements.filter {it is Directive && it.directive in directivesToMove}
-        subroutine.statements.removeAll(directives)
-        subroutine.statements.addAll(0, directives)
-
-        if(subroutine.returntypes.isEmpty()) {
-            // add the implicit return statement at the end (if it's not there yet), but only if it's not a kernel routine.
-            // and if an assembly block doesn't contain a rts/rti
-            if(subroutine.asmAddress==null && subroutine.amountOfRtsInAsm()==0) {
-                if (subroutine.statements.lastOrNull {it !is VarDecl} !is Return) {
-                    val returnStmt = Return(emptyList(), subroutine.position)
-                    returnStmt.linkParents(subroutine)
-                    subroutine.statements.add(returnStmt)
-                }
-            }
-        }
-
-        return subroutine
-    }
-
-    override fun process(scope: AnonymousScope): AnonymousScope {
-        scope.statements = scope.statements.map { it.process(this)}.toMutableList()
-        sortConstantAssignments(scope.statements)
-        return scope
-    }
-
-    override fun process(expr: BinaryExpression): IExpression {
-        val leftDt = expr.left.inferType(program)
-        val rightDt = expr.right.inferType(program)
-        if(leftDt!=null && rightDt!=null && leftDt!=rightDt) {
-            // determine common datatype and add typecast as required to make left and right equal types
-            val (commonDt, toFix) = expr.commonDatatype(leftDt, rightDt, expr.left, expr.right)
-            if(toFix!=null) {
-                when {
-                    toFix===expr.left -> {
-                        expr.left = TypecastExpression(expr.left, commonDt, true, expr.left.position)
-                        expr.left.linkParents(expr)
-                    }
-                    toFix===expr.right -> {
-                        expr.right = TypecastExpression(expr.right, commonDt, true, expr.right.position)
-                        expr.right.linkParents(expr)
-                    }
-                    else -> throw FatalAstException("confused binary expression side")
-                }
-            }
-        }
-        return super.process(expr)
-    }
-
-    private fun sortConstantAssignments(statements: MutableList<IStatement>) {
-        // sort assignments by datatype and value, so multiple initializations with the isSameAs value can be optimized (to load the value just once)
-        val result = mutableListOf<IStatement>()
-        val stmtIter = statements.iterator()
-        for(stmt in stmtIter) {
-            if(stmt is Assignment && !stmt.targets.any { it.isMemoryMapped(program.namespace) }) {
-                val constval = stmt.value.constValue(program)
-                if(constval!=null) {
-                    val (sorted, trailing) = sortConstantAssignmentSequence(stmt, stmtIter)
-                    result.addAll(sorted)
-                    if(trailing!=null)
-                        result.add(trailing)
-                }
-                else
-                    result.add(stmt)
-            }
-            else
-                result.add(stmt)
-        }
-        statements.clear()
-        statements.addAll(result)
-    }
-
-    override fun process(assignment: Assignment): IStatement {
-        val target=assignment.singleTarget
-        if(target!=null) {
-            // see if a typecast is needed to convert the value's type into the proper target type
-            val valuetype = assignment.value.inferType(program)
-            val targettype = target.inferType(program, assignment)
-            if(targettype!=null && valuetype!=null && valuetype!=targettype) {
-                if(valuetype isAssignableTo targettype) {
-                    assignment.value = TypecastExpression(assignment.value, targettype, true, assignment.value.position)
-                    assignment.value.linkParents(assignment)
-                }
-                // if they're not assignable, we'll get a proper error later from the AstChecker
-            }
-        } else TODO("multi-target assign")
-
-        return super.process(assignment)
-    }
-
-    override fun process(functionCallStatement: FunctionCallStatement): IStatement {
-        checkFunctionCallArguments(functionCallStatement, functionCallStatement.definingScope())
-        return super.process(functionCallStatement)
-    }
-
-    override fun process(functionCall: FunctionCall): IExpression {
-        checkFunctionCallArguments(functionCall, functionCall.definingScope())
-        return super.process(functionCall)
-    }
-
-    private fun checkFunctionCallArguments(call: IFunctionCall, scope: INameScope) {
-        // see if a typecast is needed to convert the arguments into the required parameter's type
-        val sub = call.target.targetStatement(scope)
-        when(sub) {
-            is Subroutine -> {
-                for(arg in sub.parameters.zip(call.arglist.withIndex())) {
-                    val argtype = arg.second.value.inferType(program)
-                    if(argtype!=null) {
-                        val requiredType = arg.first.type
-                        if (requiredType != argtype) {
-                            if (argtype isAssignableTo requiredType) {
-                                val typecasted = TypecastExpression(arg.second.value, requiredType, true, arg.second.value.position)
-                                typecasted.linkParents(arg.second.value.parent)
-                                call.arglist[arg.second.index] = typecasted
-                            }
-                            // if they're not assignable, we'll get a proper error later from the AstChecker
-                        }
-                    }
-                }
-            }
-            is BuiltinFunctionStatementPlaceholder -> {
-                // if(sub.name in setOf("lsl", "lsr", "rol", "ror", "rol2", "ror2", "memset", "memcopy", "memsetw", "swap"))
-                val func = BuiltinFunctions.getValue(sub.name)
-                if(func.pure) {
-                    // non-pure functions don't get automatic typecasts because sometimes they act directly on their parameters
-                    for (arg in func.parameters.zip(call.arglist.withIndex())) {
-                        val argtype = arg.second.value.inferType(program)
-                        if (argtype != null) {
-                            if (arg.first.possibleDatatypes.any { argtype == it })
-                                continue
-                            for (possibleType in arg.first.possibleDatatypes) {
-                                if (argtype isAssignableTo possibleType) {
-                                    val typecasted = TypecastExpression(arg.second.value, possibleType, true, arg.second.value.position)
-                                    typecasted.linkParents(arg.second.value.parent)
-                                    call.arglist[arg.second.index] = typecasted
-                                    break
-                                }
-                            }
-                        }
-                    }
-                }
-            }
-            null -> {}
-            else -> TODO("call to something weird $sub   ${call.target}")
-        }
-    }
-
-    private fun sortConstantAssignmentSequence(first: Assignment, stmtIter: MutableIterator<IStatement>): Pair<List<Assignment>, IStatement?> {
-        val sequence= mutableListOf(first)
-        var trailing: IStatement? = null
-        while(stmtIter.hasNext()) {
-            val next = stmtIter.next()
-            if(next is Assignment) {
-                val constValue = next.value.constValue(program)
-                if(constValue==null) {
-                    trailing = next
-                    break
-                }
-                sequence.add(next)
-            }
-            else {
-                trailing=next
-                break
-            }
-        }
-        val sorted = sequence.sortedWith(compareBy({it.value.inferType(program)}, {it.singleTarget?.shortString(true)}))
-        return Pair(sorted, trailing)
-    }
-
-    override fun process(typecast: TypecastExpression): IExpression {
-        // warn about any implicit type casts to Float, because that may not be intended
-        if(typecast.implicit && typecast.type in setOf(DataType.FLOAT, DataType.ARRAY_F)) {
-            printWarning("byte or word value implicitly converted to float. Suggestion: use explicit cast as float, a float number, or revert to integer arithmetic", typecast.position)
-        }
-        return super.process(typecast)
-    }
-}
-
-
-private class VarInitValueAndAddressOfCreator(private val namespace: INameScope): IAstProcessor {
-    // For VarDecls that declare an initialization value:
-    // Replace the vardecl with an assignment (to set the initial value),
-    // and add a new vardecl with the default constant value of that type (usually zero) to the scope.
-    // This makes sure the variables get reset to the intended value on a next run of the program.
-    // Variable decls without a value don't get this treatment, which means they retain the last
-    // value they had when restarting the program.
-    // This is done in a separate step because it interferes with the namespace lookup of symbols
-    // in other ast processors.
-
-    // Also takes care to insert AddressOf (&) expression where required (string params to a UWORD function param etc).
-
-    private val vardeclsToAdd = mutableMapOf<INameScope, MutableMap<String, VarDecl>>()
-
-    override fun process(module: Module) {
-        vardeclsToAdd.clear()
-        super.process(module)
-
-        // add any new vardecls to the various scopes
-        for(decl in vardeclsToAdd)
-            for(d in decl.value) {
-                d.value.linkParents(decl.key as Node)
-                decl.key.statements.add(0, d.value)
-            }
-    }
-
-    override fun process(decl: VarDecl): IStatement {
-        super.process(decl)
-        if(decl.type!=VarDeclType.VAR || decl.value==null)
-            return decl
-
-        if(decl.datatype in NumericDatatypes) {
-            val scope = decl.definingScope()
-            addVarDecl(scope, decl.asDefaultValueDecl(null))
-            val declvalue = decl.value!!
-            val value =
-                    if(declvalue is LiteralValue) {
-                        val converted = declvalue.intoDatatype(decl.datatype)
-                        converted ?: declvalue
-                    }
-                    else
-                        declvalue
-            val identifierName = listOf(decl.name)    //  // TODO this was: (scoped name) decl.scopedname.split(".")
-            return VariableInitializationAssignment(
-                    AssignTarget(null, IdentifierReference(identifierName, decl.position), null, null, decl.position),
-                    null,
-                    value,
-                    decl.position
-            )
-        }
-        return decl
-    }
-
-    override fun process(functionCall: FunctionCall): IExpression {
-        val targetStatement = functionCall.target.targetSubroutine(namespace)
-        if(targetStatement!=null) {
-            var node: Node = functionCall
-            while(node !is IStatement)
-                node=node.parent
-            addAddressOfExprIfNeeded(targetStatement, functionCall.arglist, node)
-        }
-        return functionCall
-    }
-
-    override fun process(functionCallStatement: FunctionCallStatement): IStatement {
-        val targetStatement = functionCallStatement.target.targetSubroutine(namespace)
-        if(targetStatement!=null)
-            addAddressOfExprIfNeeded(targetStatement, functionCallStatement.arglist, functionCallStatement)
-        return functionCallStatement
-    }
-
-    private fun addAddressOfExprIfNeeded(subroutine: Subroutine, arglist: MutableList<IExpression>, parent: IStatement) {
-        // functions that accept UWORD and are given an array type, or string, will receive the AddressOf (memory location) of that value instead.
-        for(argparam in subroutine.parameters.withIndex().zip(arglist)) {
-            if(argparam.first.value.type==DataType.UWORD || argparam.first.value.type in StringDatatypes) {
-                if(argparam.second is AddressOf)
-                    continue
-                val idref = argparam.second as? IdentifierReference
-                val strvalue = argparam.second as? LiteralValue
-                if(idref!=null) {
-                    val variable = idref.targetVarDecl(namespace)
-                    if(variable!=null && (variable.datatype in StringDatatypes || variable.datatype in ArrayDatatypes)) {
-                        val pointerExpr = AddressOf(idref, idref.position)
-                        pointerExpr.scopedname = parent.makeScopedName(idref.nameInSource.single())
-                        pointerExpr.linkParents(arglist[argparam.first.index].parent)
-                        arglist[argparam.first.index] = pointerExpr
-                    }
-                }
-                else if(strvalue!=null) {
-                    if(strvalue.isString) {
-                        // replace the argument with &autovar
-                        val autoVarName = "$autoHeapValuePrefix${strvalue.heapId}"
-                        val autoHeapvarRef = IdentifierReference(listOf(autoVarName), strvalue.position)
-                        val pointerExpr = AddressOf(autoHeapvarRef, strvalue.position)
-                        pointerExpr.scopedname = parent.makeScopedName(autoVarName)
-                        pointerExpr.linkParents(arglist[argparam.first.index].parent)
-                        arglist[argparam.first.index] = pointerExpr
-                        // add a vardecl so that the autovar can be resolved in later lookups
-                        val variable = VarDecl(VarDeclType.VAR, strvalue.type, false, null, autoVarName, strvalue,
-                                isArray = false, autoGenerated = false, position=strvalue.position)
-                        addVarDecl(strvalue.definingScope(), variable)
-                    }
-                }
-            }
-        }
-    }
-
-    private fun addVarDecl(scope: INameScope, variable: VarDecl) {
-        if(scope !in vardeclsToAdd)
-            vardeclsToAdd[scope] = mutableMapOf()
-        vardeclsToAdd.getValue(scope)[variable.name]=variable
-    }
-
-}

compiler/src/prog8/ast/antlr/Antr2Kotlin.kt

@@ -0,0 +1,646 @@
+package prog8.ast.antlr
+
+import org.antlr.v4.runtime.IntStream
+import org.antlr.v4.runtime.ParserRuleContext
+import org.antlr.v4.runtime.tree.TerminalNode
+import prog8.ast.Module
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.statements.*
+import prog8.compiler.target.CompilationTarget
+import prog8.parser.CustomLexer
+import prog8.parser.prog8Parser
+import java.io.CharConversionException
+import java.io.File
+import java.nio.file.Path
+
+
+/***************** Antlr Extension methods to create AST ****************/
+
+private data class NumericLiteral(val number: Number, val datatype: DataType)
+
+
+fun prog8Parser.ModuleContext.toAst(name: String, isLibrary: Boolean, source: Path) : Module {
+    val nameWithoutSuffix = if(name.endsWith(".p8")) name.substringBeforeLast('.') else name
+    return Module(nameWithoutSuffix, modulestatement().asSequence().map { it.toAst(isLibrary) }.toMutableList(), toPosition(), isLibrary, source)
+}
+
+
+private fun ParserRuleContext.toPosition() : Position {
+    val customTokensource = this.start.tokenSource as? CustomLexer
+    val filename =
+            when {
+                customTokensource!=null -> customTokensource.modulePath.fileName.toString()
+                start.tokenSource.sourceName == IntStream.UNKNOWN_SOURCE_NAME -> "@internal@"
+                else -> File(start.inputStream.sourceName).name
+            }
+    // note: be ware of TAB characters in the source text, they count as 1 column...
+    return Position(filename, start.line, start.charPositionInLine, stop.charPositionInLine + stop.text.length)
+}
+
+
+private fun prog8Parser.ModulestatementContext.toAst(isInLibrary: Boolean) : Statement {
+    val directive = directive()?.toAst()
+    if(directive!=null) return directive
+
+    val block = block()?.toAst(isInLibrary)
+    if(block!=null) return block
+
+    throw FatalAstException(text)
+}
+
+
+private fun prog8Parser.BlockContext.toAst(isInLibrary: Boolean) : Statement =
+        Block(identifier().text, integerliteral()?.toAst()?.number?.toInt(), statement_block().toAst(), isInLibrary, toPosition())
+
+
+private fun prog8Parser.Statement_blockContext.toAst(): MutableList<Statement> =
+        statement().asSequence().map { it.toAst() }.toMutableList()
+
+
+private fun prog8Parser.StatementContext.toAst() : Statement {
+    vardecl()?.let { return it.toAst() }
+
+    varinitializer()?.let {
+        val vd = it.vardecl()
+        return VarDecl(
+                VarDeclType.VAR,
+                vd.datatype()?.toAst() ?: DataType.STRUCT,
+                if(vd.ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE,
+                vd.arrayindex()?.toAst(),
+                vd.varname.text,
+                null,
+                it.expression().toAst(),
+                vd.ARRAYSIG() != null || vd.arrayindex() != null,
+                false,
+                it.toPosition()
+        )
+    }
+
+    structvarinitializer()?.let {
+        val vd = it.structvardecl()
+        return VarDecl(
+                VarDeclType.VAR,
+                DataType.STRUCT,
+                ZeropageWish.NOT_IN_ZEROPAGE,
+                null,
+                vd.varname.text,
+                vd.structname.text,
+                it.expression().toAst(),
+                isArray = false,
+                autogeneratedDontRemove = false,
+                position = it.toPosition()
+        )
+    }
+
+    structvardecl()?.let {
+        return VarDecl(
+                VarDeclType.VAR,
+                DataType.STRUCT,
+                ZeropageWish.NOT_IN_ZEROPAGE,
+                null,
+                it.varname.text,
+                it.structname.text,
+                null,
+                isArray = false,
+                autogeneratedDontRemove = false,
+                position = it.toPosition()
+        )
+    }
+
+    constdecl()?.let {
+        val cvarinit = it.varinitializer()
+        val vd = cvarinit.vardecl()
+        return VarDecl(
+                VarDeclType.CONST,
+                vd.datatype()?.toAst() ?: DataType.STRUCT,
+                if(vd.ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE,
+                vd.arrayindex()?.toAst(),
+                vd.varname.text,
+                null,
+                cvarinit.expression().toAst(),
+                vd.ARRAYSIG() != null || vd.arrayindex() != null,
+                false,
+                cvarinit.toPosition()
+        )
+    }
+
+    memoryvardecl()?.let {
+        val mvarinit = it.varinitializer()
+        val vd = mvarinit.vardecl()
+        return VarDecl(
+                VarDeclType.MEMORY,
+                vd.datatype()?.toAst() ?: DataType.STRUCT,
+                if(vd.ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE,
+                vd.arrayindex()?.toAst(),
+                vd.varname.text,
+                null,
+                mvarinit.expression().toAst(),
+                vd.ARRAYSIG() != null || vd.arrayindex() != null,
+                false,
+                mvarinit.toPosition()
+        )
+    }
+
+    assignment()?.let {
+        return Assignment(it.assign_target().toAst(), null, it.expression().toAst(), it.toPosition())
+    }
+
+    augassignment()?.let {
+        return Assignment(it.assign_target().toAst(),
+                it.operator.text,
+                it.expression().toAst(),
+                it.toPosition())
+    }
+
+    postincrdecr()?.let {
+        return PostIncrDecr(it.assign_target().toAst(), it.operator.text, it.toPosition())
+    }
+
+    val directive = directive()?.toAst()
+    if(directive!=null) return directive
+
+    val label = labeldef()?.toAst()
+    if(label!=null) return label
+
+    val jump = unconditionaljump()?.toAst()
+    if(jump!=null) return jump
+
+    val fcall = functioncall_stmt()?.toAst()
+    if(fcall!=null) return fcall
+
+    val ifstmt = if_stmt()?.toAst()
+    if(ifstmt!=null) return ifstmt
+
+    val returnstmt = returnstmt()?.toAst()
+    if(returnstmt!=null) return returnstmt
+
+    val sub = subroutine()?.toAst()
+    if(sub!=null) return sub
+
+    val asm = inlineasm()?.toAst()
+    if(asm!=null) return asm
+
+    val branchstmt = branch_stmt()?.toAst()
+    if(branchstmt!=null) return branchstmt
+
+    val forloop = forloop()?.toAst()
+    if(forloop!=null) return forloop
+
+    val repeatloop = repeatloop()?.toAst()
+    if(repeatloop!=null) return repeatloop
+
+    val whileloop = whileloop()?.toAst()
+    if(whileloop!=null) return whileloop
+
+    val breakstmt = breakstmt()?.toAst()
+    if(breakstmt!=null) return breakstmt
+
+    val continuestmt = continuestmt()?.toAst()
+    if(continuestmt!=null) return continuestmt
+
+    val asmsubstmt = asmsubroutine()?.toAst()
+    if(asmsubstmt!=null) return asmsubstmt
+
+    val whenstmt = whenstmt()?.toAst()
+    if(whenstmt!=null) return whenstmt
+
+    structdecl()?.let {
+        return StructDecl(it.identifier().text,
+                it.vardecl().map { vd->vd.toAst() }.toMutableList(),
+                toPosition())
+    }
+
+    throw FatalAstException("unprocessed source text (are we missing ast conversion rules for parser elements?): $text")
+}
+
+private fun prog8Parser.AsmsubroutineContext.toAst(): Statement {
+    val name = identifier().text
+    val address = asmsub_address()?.address?.toAst()?.number?.toInt()
+    val params = asmsub_params()?.toAst() ?: emptyList()
+    val returns = asmsub_returns()?.toAst() ?: emptyList()
+    val normalParameters = params.map { SubroutineParameter(it.name, it.type, it.position) }
+    val normalReturnvalues = returns.map { it.type }
+    val paramRegisters = params.map { RegisterOrStatusflag(it.registerOrPair, it.statusflag, it.stack) }
+    val returnRegisters = returns.map { RegisterOrStatusflag(it.registerOrPair, it.statusflag, it.stack) }
+    val clobbers = asmsub_clobbers()?.clobber()?.toAst() ?: emptySet()
+    val statements = statement_block()?.toAst() ?: mutableListOf()
+    return Subroutine(name, normalParameters, normalReturnvalues,
+            paramRegisters, returnRegisters, clobbers, address, true, statements, toPosition())
+}
+
+private class AsmSubroutineParameter(name: String,
+                                     type: DataType,
+                                     val registerOrPair: RegisterOrPair?,
+                                     val statusflag: Statusflag?,
+                                     val stack: Boolean,
+                                     position: Position) : SubroutineParameter(name, type, position)
+
+private class AsmSubroutineReturn(val type: DataType,
+                                  val registerOrPair: RegisterOrPair?,
+                                  val statusflag: Statusflag?,
+                                  val stack: Boolean,
+                                  val position: Position)
+
+private fun prog8Parser.ClobberContext.toAst(): Set<Register>
+        = this.register().asSequence().map { it.toAst() }.toSet()
+
+
+private fun prog8Parser.Asmsub_returnsContext.toAst(): List<AsmSubroutineReturn>
+        = asmsub_return().map { AsmSubroutineReturn(it.datatype().toAst(), it.registerorpair()?.toAst(), it.statusregister()?.toAst(), !it.stack?.text.isNullOrEmpty(), toPosition()) }
+
+private fun prog8Parser.Asmsub_paramsContext.toAst(): List<AsmSubroutineParameter>
+        = asmsub_param().map {
+    val vardecl = it.vardecl()
+    val datatype = vardecl.datatype()?.toAst() ?: DataType.STRUCT
+    AsmSubroutineParameter(vardecl.varname.text, datatype,
+            it.registerorpair()?.toAst(),
+            it.statusregister()?.toAst(),
+            !it.stack?.text.isNullOrEmpty(), toPosition())
+}
+
+
+private fun prog8Parser.StatusregisterContext.toAst() = Statusflag.valueOf(text)
+
+
+private fun prog8Parser.Functioncall_stmtContext.toAst(): Statement {
+    val void = this.VOID() != null
+    val location = scoped_identifier().toAst()
+    return if(expression_list() == null)
+        FunctionCallStatement(location, mutableListOf(), void, toPosition())
+    else
+        FunctionCallStatement(location, expression_list().toAst().toMutableList(), void, toPosition())
+}
+
+
+private fun prog8Parser.FunctioncallContext.toAst(): FunctionCall {
+    val location = scoped_identifier().toAst()
+    return if(expression_list() == null)
+        FunctionCall(location, mutableListOf(), toPosition())
+    else
+        FunctionCall(location, expression_list().toAst().toMutableList(), toPosition())
+}
+
+
+private fun prog8Parser.InlineasmContext.toAst() =
+        InlineAssembly(INLINEASMBLOCK().text, toPosition())
+
+
+private fun prog8Parser.ReturnstmtContext.toAst() : Return {
+    return Return(expression()?.toAst(), toPosition())
+}
+
+private fun prog8Parser.UnconditionaljumpContext.toAst(): Jump {
+    val address = integerliteral()?.toAst()?.number?.toInt()
+    val identifier = scoped_identifier()?.toAst()
+    return Jump(address, identifier, null, toPosition())
+}
+
+
+private fun prog8Parser.LabeldefContext.toAst(): Statement =
+        Label(children[0].text, toPosition())
+
+
+private fun prog8Parser.SubroutineContext.toAst() : Subroutine {
+    return Subroutine(identifier().text,
+            sub_params()?.toAst() ?: emptyList(),
+            sub_return_part()?.toAst() ?: emptyList(),
+            emptyList(),
+            emptyList(),
+            emptySet(),
+            null,
+            false,
+            statement_block()?.toAst() ?: mutableListOf(),
+            toPosition())
+}
+
+private fun prog8Parser.Sub_return_partContext.toAst(): List<DataType> {
+    val returns = sub_returns() ?: return emptyList()
+    return returns.datatype().map { it.toAst() }
+}
+
+
+private fun prog8Parser.Sub_paramsContext.toAst(): List<SubroutineParameter> =
+        vardecl().map {
+            val datatype = it.datatype()?.toAst() ?: DataType.STRUCT
+            SubroutineParameter(it.varname.text, datatype, it.toPosition())
+        }
+
+
+private fun prog8Parser.Assign_targetContext.toAst() : AssignTarget {
+    val register = register()?.toAst()
+    val identifier = scoped_identifier()
+    return when {
+        register!=null -> AssignTarget(register, null, null, null, toPosition())
+        identifier!=null -> AssignTarget(null, identifier.toAst(), null, null, toPosition())
+        arrayindexed()!=null -> AssignTarget(null, null, arrayindexed().toAst(), null, toPosition())
+        directmemory()!=null -> AssignTarget(null, null, null, DirectMemoryWrite(directmemory().expression().toAst(), toPosition()), toPosition())
+        else -> AssignTarget(null, scoped_identifier()?.toAst(), null, null, toPosition())
+    }
+}
+
+private fun prog8Parser.RegisterContext.toAst() = Register.valueOf(text.toUpperCase())
+
+private fun prog8Parser.DatatypeContext.toAst() = DataType.valueOf(text.toUpperCase())
+
+private fun prog8Parser.RegisterorpairContext.toAst() = RegisterOrPair.valueOf(text.toUpperCase())
+
+
+private fun prog8Parser.ArrayindexContext.toAst() : ArrayIndex =
+        ArrayIndex(expression().toAst(), toPosition())
+
+
+private fun prog8Parser.DirectiveContext.toAst() : Directive =
+        Directive(directivename.text, directivearg().map { it.toAst() }, toPosition())
+
+
+private fun prog8Parser.DirectiveargContext.toAst() : DirectiveArg =
+        DirectiveArg(stringliteral()?.text, identifier()?.text, integerliteral()?.toAst()?.number?.toInt(), toPosition())
+
+
+private fun prog8Parser.IntegerliteralContext.toAst(): NumericLiteral {
+    fun makeLiteral(text: String, radix: Int, forceWord: Boolean): NumericLiteral {
+        val integer: Int
+        var datatype = DataType.UBYTE
+        when (radix) {
+            10 -> {
+                integer = try {
+                    text.toInt()
+                } catch(x: NumberFormatException) {
+                    throw AstException("${toPosition()} invalid decimal literal ${x.message}")
+                }
+                datatype = when(integer) {
+                    in 0..255 -> DataType.UBYTE
+                    in -128..127 -> DataType.BYTE
+                    in 0..65535 -> DataType.UWORD
+                    in -32768..32767 -> DataType.WORD
+                    else -> DataType.FLOAT
+                }
+            }
+            2 -> {
+                if(text.length>8)
+                    datatype = DataType.UWORD
+                try {
+                    integer = text.toInt(2)
+                } catch(x: NumberFormatException) {
+                    throw AstException("${toPosition()} invalid binary literal ${x.message}")
+                }
+            }
+            16 -> {
+                if(text.length>2)
+                    datatype = DataType.UWORD
+                try {
+                    integer = text.toInt(16)
+                } catch(x: NumberFormatException) {
+                    throw AstException("${toPosition()} invalid hexadecimal literal ${x.message}")
+                }
+            }
+            else -> throw FatalAstException("invalid radix")
+        }
+        return NumericLiteral(integer, if (forceWord) DataType.UWORD else datatype)
+    }
+    val terminal: TerminalNode = children[0] as TerminalNode
+    val integerPart = this.intpart.text
+    return when (terminal.symbol.type) {
+        prog8Parser.DEC_INTEGER -> makeLiteral(integerPart, 10, wordsuffix()!=null)
+        prog8Parser.HEX_INTEGER -> makeLiteral(integerPart.substring(1), 16, wordsuffix()!=null)
+        prog8Parser.BIN_INTEGER -> makeLiteral(integerPart.substring(1), 2, wordsuffix()!=null)
+        else -> throw FatalAstException(terminal.text)
+    }
+}
+
+
+private fun prog8Parser.ExpressionContext.toAst() : Expression {
+
+    val litval = literalvalue()
+    if(litval!=null) {
+        val booleanlit = litval.booleanliteral()?.toAst()
+        return if(booleanlit!=null) {
+            NumericLiteralValue.fromBoolean(booleanlit, litval.toPosition())
+        }
+        else {
+            val intLit = litval.integerliteral()?.toAst()
+            when {
+                intLit!=null -> when(intLit.datatype) {
+                    DataType.UBYTE -> NumericLiteralValue(DataType.UBYTE, intLit.number.toShort(), litval.toPosition())
+                    DataType.BYTE -> NumericLiteralValue(DataType.BYTE, intLit.number.toShort(), litval.toPosition())
+                    DataType.UWORD -> NumericLiteralValue(DataType.UWORD, intLit.number.toInt(), litval.toPosition())
+                    DataType.WORD -> NumericLiteralValue(DataType.WORD, intLit.number.toInt(), litval.toPosition())
+                    DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, intLit.number.toDouble(), litval.toPosition())
+                    else -> throw FatalAstException("invalid datatype for numeric literal")
+                }
+                litval.floatliteral()!=null -> NumericLiteralValue(DataType.FLOAT, litval.floatliteral().toAst(), litval.toPosition())
+                litval.stringliteral()!=null -> StringLiteralValue(unescape(litval.stringliteral().text, litval.toPosition()), litval.toPosition())
+                litval.charliteral()!=null -> {
+                    try {
+                        NumericLiteralValue(DataType.UBYTE, CompilationTarget.encodeString(
+                                unescape(litval.charliteral().text, litval.toPosition()))[0], litval.toPosition())
+                    } catch (ce: CharConversionException) {
+                        throw SyntaxError(ce.message ?: ce.toString(), litval.toPosition())
+                    }
+                }
+                litval.arrayliteral()!=null -> {
+                    val array = litval.arrayliteral().toAst()
+                    // the actual type of the arraysize can not yet be determined here (missing namespace & heap)
+                    // the ConstantFold takes care of that and converts the type if needed.
+                    ArrayLiteralValue(DataType.ARRAY_UB, array, position = litval.toPosition())
+                }
+                litval.structliteral()!=null -> {
+                    val values = litval.structliteral().expression().map { it.toAst() }
+                    StructLiteralValue(values, litval.toPosition())
+                }
+                else -> throw FatalAstException("invalid parsed literal")
+            }
+        }
+    }
+
+    if(register()!=null)
+        return RegisterExpr(register().toAst(), register().toPosition())
+
+    if(scoped_identifier()!=null)
+        return scoped_identifier().toAst()
+
+    if(bop!=null)
+        return BinaryExpression(left.toAst(), bop.text, right.toAst(), toPosition())
+
+    if(prefix!=null)
+        return PrefixExpression(prefix.text, expression(0).toAst(), toPosition())
+
+    val funcall = functioncall()?.toAst()
+    if(funcall!=null) return funcall
+
+    if (rangefrom!=null && rangeto!=null) {
+        val step = rangestep?.toAst() ?: NumericLiteralValue(DataType.UBYTE, 1, toPosition())
+        return RangeExpr(rangefrom.toAst(), rangeto.toAst(), step, toPosition())
+    }
+
+    if(childCount==3 && children[0].text=="(" && children[2].text==")")
+        return expression(0).toAst()        // expression within ( )
+
+    if(arrayindexed()!=null)
+        return arrayindexed().toAst()
+
+    if(typecast()!=null)
+        return TypecastExpression(expression(0).toAst(), typecast().datatype().toAst(), false, toPosition())
+
+    if(directmemory()!=null)
+        return DirectMemoryRead(directmemory().expression().toAst(), toPosition())
+
+    if(addressof()!=null)
+        return AddressOf(addressof().scoped_identifier().toAst(), toPosition())
+
+    throw FatalAstException(text)
+}
+
+
+private fun prog8Parser.ArrayindexedContext.toAst(): ArrayIndexedExpression {
+    return ArrayIndexedExpression(scoped_identifier().toAst(),
+            arrayindex().toAst(),
+            toPosition())
+}
+
+
+private fun prog8Parser.Expression_listContext.toAst() = expression().map{ it.toAst() }
+
+
+private fun prog8Parser.IdentifierContext.toAst() : IdentifierReference =
+        IdentifierReference(listOf(text), toPosition())
+
+
+private fun prog8Parser.Scoped_identifierContext.toAst() : IdentifierReference =
+        IdentifierReference(NAME().map { it.text }, toPosition())
+
+
+private fun prog8Parser.FloatliteralContext.toAst() = text.toDouble()
+
+
+private fun prog8Parser.BooleanliteralContext.toAst() = when(text) {
+    "true" -> true
+    "false" -> false
+    else -> throw FatalAstException(text)
+}
+
+
+private fun prog8Parser.ArrayliteralContext.toAst() : Array<Expression> =
+        expression().map { it.toAst() }.toTypedArray()
+
+private fun prog8Parser.If_stmtContext.toAst(): IfStatement {
+    val condition = expression().toAst()
+    val trueStatements = statement_block()?.toAst() ?: mutableListOf(statement().toAst())
+    val elseStatements = else_part()?.toAst() ?: mutableListOf()
+    val trueScope = AnonymousScope(trueStatements, statement_block()?.toPosition()
+            ?: statement().toPosition())
+    val elseScope = AnonymousScope(elseStatements, else_part()?.toPosition() ?: toPosition())
+    return IfStatement(condition, trueScope, elseScope, toPosition())
+}
+
+private fun prog8Parser.Else_partContext.toAst(): MutableList<Statement> {
+    return statement_block()?.toAst() ?: mutableListOf(statement().toAst())
+}
+
+
+private fun prog8Parser.Branch_stmtContext.toAst(): BranchStatement {
+    val branchcondition = branchcondition().toAst()
+    val trueStatements = statement_block()?.toAst() ?: mutableListOf(statement().toAst())
+    val elseStatements = else_part()?.toAst() ?: mutableListOf()
+    val trueScope = AnonymousScope(trueStatements, statement_block()?.toPosition()
+            ?: statement().toPosition())
+    val elseScope = AnonymousScope(elseStatements, else_part()?.toPosition() ?: toPosition())
+    return BranchStatement(branchcondition, trueScope, elseScope, toPosition())
+}
+
+private fun prog8Parser.BranchconditionContext.toAst() = BranchCondition.valueOf(text.substringAfter('_').toUpperCase())
+
+
+private fun prog8Parser.ForloopContext.toAst(): ForLoop {
+    val loopregister = register()?.toAst()
+    val loopvar = identifier()?.toAst()
+    val iterable = expression()!!.toAst()
+    val scope =
+            if(statement()!=null)
+                AnonymousScope(mutableListOf(statement().toAst()), statement().toPosition())
+            else
+                AnonymousScope(statement_block().toAst(), statement_block().toPosition())
+    return ForLoop(loopregister, loopvar, iterable, scope, toPosition())
+}
+
+
+private fun prog8Parser.ContinuestmtContext.toAst() = Continue(toPosition())
+
+private fun prog8Parser.BreakstmtContext.toAst() = Break(toPosition())
+
+
+private fun prog8Parser.WhileloopContext.toAst(): WhileLoop {
+    val condition = expression().toAst()
+    val statements = statement_block()?.toAst() ?: mutableListOf(statement().toAst())
+    val scope = AnonymousScope(statements, statement_block()?.toPosition()
+            ?: statement().toPosition())
+    return WhileLoop(condition, scope, toPosition())
+}
+
+
+private fun prog8Parser.RepeatloopContext.toAst(): RepeatLoop {
+    val untilCondition = expression().toAst()
+    val statements = statement_block()?.toAst() ?: mutableListOf(statement().toAst())
+    val scope = AnonymousScope(statements, statement_block()?.toPosition()
+            ?: statement().toPosition())
+    return RepeatLoop(scope, untilCondition, toPosition())
+}
+
+private fun prog8Parser.WhenstmtContext.toAst(): WhenStatement {
+    val condition = expression().toAst()
+    val choices = this.when_choice()?.map { it.toAst() }?.toMutableList() ?: mutableListOf()
+    return WhenStatement(condition, choices, toPosition())
+}
+
+private fun prog8Parser.When_choiceContext.toAst(): WhenChoice {
+    val values = expression_list()?.toAst()
+    val stmt = statement()?.toAst()
+    val stmtBlock = statement_block()?.toAst()?.toMutableList() ?: mutableListOf()
+    if(stmt!=null)
+        stmtBlock.add(stmt)
+    val scope = AnonymousScope(stmtBlock, toPosition())
+    return WhenChoice(values, scope, toPosition())
+}
+
+private fun prog8Parser.VardeclContext.toAst(): VarDecl {
+    return VarDecl(
+            VarDeclType.VAR,
+            datatype()?.toAst() ?: DataType.STRUCT,
+            if(ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE,
+            arrayindex()?.toAst(),
+            varname.text,
+            null,
+            null,
+            ARRAYSIG() != null || arrayindex() != null,
+            false,
+            toPosition()
+    )
+}
+
+internal fun escape(str: String) = str.replace("\t", "\\t").replace("\n", "\\n").replace("\r", "\\r")
+
+internal fun unescape(str: String, position: Position): String {
+    val result = mutableListOf<Char>()
+    val iter = str.iterator()
+    while(iter.hasNext()) {
+        val c = iter.nextChar()
+        if(c=='\\') {
+            val ec = iter.nextChar()
+            result.add(when(ec) {
+                '\\' -> '\\'
+                'n' -> '\n'
+                'r' -> '\r'
+                '"' -> '"'
+                'u' -> {
+                    "${iter.nextChar()}${iter.nextChar()}${iter.nextChar()}${iter.nextChar()}".toInt(16).toChar()
+                }
+                else -> throw SyntaxError("invalid escape char in string: \\$ec", position)
+            })
+        } else {
+            result.add(c)
+        }
+    }
+    return result.joinToString("")
+}
+

compiler/src/prog8/ast/base/Base.kt

@@ -0,0 +1,150 @@
+package prog8.ast.base
+
+import prog8.ast.Node
+import prog8.compiler.target.CompilationTarget
+
+
+/**************************** AST Data classes ****************************/
+
+enum class DataType {
+    UBYTE,              // pass by value
+    BYTE,               // pass by value
+    UWORD,              // pass by value
+    WORD,               // pass by value
+    FLOAT,              // pass by value
+    STR,                // pass by reference
+    ARRAY_UB,           // pass by reference
+    ARRAY_B,            // pass by reference
+    ARRAY_UW,           // pass by reference
+    ARRAY_W,            // pass by reference
+    ARRAY_F,            // pass by reference
+    STRUCT;             // pass by reference
+
+    /**
+     * is the type assignable to the given other type?
+     */
+    infix fun isAssignableTo(targetType: DataType) =
+            // what types are assignable to others without loss of precision?
+            when(this) {
+                UBYTE -> targetType in setOf(UBYTE, WORD, UWORD, FLOAT)
+                BYTE -> targetType in setOf(BYTE, WORD, FLOAT)
+                UWORD -> targetType in setOf(UWORD, FLOAT)
+                WORD -> targetType in setOf(WORD, FLOAT)
+                FLOAT -> targetType == FLOAT
+                STR -> targetType == STR
+                in ArrayDatatypes -> targetType == this
+                else -> false
+            }
+
+
+    infix fun isAssignableTo(targetTypes: Set<DataType>) = targetTypes.any { this isAssignableTo it }
+
+    infix fun largerThan(other: DataType) =
+            when(this) {
+                in ByteDatatypes -> false
+                in WordDatatypes -> other in ByteDatatypes
+                else -> true
+            }
+
+    infix fun equalsSize(other: DataType) =
+            when(this) {
+                in ByteDatatypes -> other in ByteDatatypes
+                in WordDatatypes -> other in WordDatatypes
+                else -> false
+            }
+
+    fun memorySize(): Int {
+        return when(this) {
+            in ByteDatatypes -> 1
+            in WordDatatypes -> 2
+            FLOAT -> CompilationTarget.machine.FLOAT_MEM_SIZE
+            in PassByReferenceDatatypes -> 2
+            else -> -9999999
+        }
+    }
+}
+
+enum class Register {
+    A,
+    X,
+    Y
+}
+
+enum class RegisterOrPair {
+    A,
+    X,
+    Y,
+    AX,
+    AY,
+    XY
+}       // only used in parameter and return value specs in asm subroutines
+
+enum class Statusflag {
+    Pc,
+    Pz,
+    Pv,
+    Pn
+}
+
+enum class BranchCondition {
+    CS,
+    CC,
+    EQ,
+    Z,
+    NE,
+    NZ,
+    VS,
+    VC,
+    MI,
+    NEG,
+    PL,
+    POS
+}
+
+enum class VarDeclType {
+    VAR,
+    CONST,
+    MEMORY
+}
+
+val ByteDatatypes = setOf(DataType.UBYTE, DataType.BYTE)
+val WordDatatypes = setOf(DataType.UWORD, DataType.WORD)
+val IntegerDatatypes = setOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD)
+val NumericDatatypes = setOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD, DataType.FLOAT)
+val ArrayDatatypes = setOf(DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W, DataType.ARRAY_F)
+val IterableDatatypes = setOf(
+        DataType.STR,
+        DataType.ARRAY_UB, DataType.ARRAY_B,
+        DataType.ARRAY_UW, DataType.ARRAY_W,
+        DataType.ARRAY_F)
+val PassByValueDatatypes = NumericDatatypes
+val PassByReferenceDatatypes = IterableDatatypes.plus(DataType.STRUCT)
+val ArrayElementTypes = mapOf(
+        DataType.STR to DataType.UBYTE,
+        DataType.ARRAY_B to DataType.BYTE,
+        DataType.ARRAY_UB to DataType.UBYTE,
+        DataType.ARRAY_W to DataType.WORD,
+        DataType.ARRAY_UW to DataType.UWORD,
+        DataType.ARRAY_F to DataType.FLOAT)
+
+// find the parent node of a specific type or interface
+// (useful to figure out in what namespace/block something is defined, etc)
+inline fun <reified T> findParentNode(node: Node): T? {
+    var candidate = node.parent
+    while(candidate !is T && candidate !is ParentSentinel)
+        candidate = candidate.parent
+    return if(candidate is ParentSentinel)
+        null
+    else
+        candidate as T
+}
+
+object ParentSentinel : Node {
+    override val position = Position("<<sentinel>>", 0, 0, 0)
+    override var parent: Node = this
+    override fun linkParents(parent: Node) {}
+}
+
+data class Position(val file: String, val line: Int, val startCol: Int, val endCol: Int) {
+    override fun toString(): String = "[$file: line $line col ${startCol+1}-${endCol+1}]"
+}

compiler/src/prog8/ast/base/ErrorReporting.kt

@@ -0,0 +1,37 @@
+package prog8.ast.base
+
+import prog8.parser.ParsingFailedError
+
+
+fun printErrors(errors: List<Any>, moduleName: String) {
+    val reportedMessages = mutableSetOf<String>()
+    System.err.print("\u001b[91m")  // bright red
+    errors.forEach {
+        val msg = it.toString()
+        if(msg !in reportedMessages) {
+            System.err.println(msg)
+            reportedMessages.add(msg)
+        }
+    }
+    System.err.print("\u001b[0m")  // reset color
+    if(reportedMessages.isNotEmpty())
+        throw ParsingFailedError("There are ${reportedMessages.size} errors in module '$moduleName'.")
+}
+
+
+fun printWarning(msg: String, position: Position, detailInfo: String?=null) {
+    print("\u001b[93m")  // bright yellow
+    print("$position Warning: $msg")
+    if(detailInfo==null)
+        print("\n")
+    else
+        println(": $detailInfo\n")
+    print("\u001b[0m")  // normal
+}
+
+
+fun printWarning(msg: String) {
+    print("\u001b[93m")  // bright yellow
+    print("Warning: $msg")
+    print("\u001b[0m\n")  // normal
+}

compiler/src/prog8/ast/base/Errors.kt

@@ -0,0 +1,22 @@
+package prog8.ast.base
+
+import prog8.ast.expressions.IdentifierReference
+
+class FatalAstException (override var message: String) : Exception(message)
+
+open class AstException (override var message: String) : Exception(message)
+
+class SyntaxError(override var message: String, val position: Position) : AstException(message) {
+    override fun toString() = "$position Syntax error: $message"
+}
+
+open class NameError(override var message: String, val position: Position) : AstException(message) {
+    override fun toString() = "$position Name error: $message"
+}
+
+class ExpressionError(message: String, val position: Position) : AstException(message) {
+    override fun toString() = "$position Error: $message"
+}
+
+class UndefinedSymbolError(symbol: IdentifierReference)
+    : NameError("undefined symbol: ${symbol.nameInSource.joinToString(".")}", symbol.position)

compiler/src/prog8/ast/base/Extensions.kt

@@ -0,0 +1,69 @@
+package prog8.ast.base
+
+import prog8.ast.Module
+import prog8.ast.Program
+import prog8.ast.processing.*
+import prog8.compiler.CompilationOptions
+import prog8.optimizer.FlattenAnonymousScopesAndRemoveNops
+
+
+// the name of the subroutine that should be called for every block to initialize its variables
+internal const val initvarsSubName="prog8_init_vars"
+
+
+internal fun Program.removeNopsFlattenAnonScopes() {
+    val flattener = FlattenAnonymousScopesAndRemoveNops()
+    flattener.visit(this)
+}
+
+
+internal fun Program.checkValid(compilerOptions: CompilationOptions) {
+    val checker = AstChecker(this, compilerOptions)
+    checker.visit(this)
+    printErrors(checker.result(), name)
+}
+
+
+internal fun Program.anonscopeVarsCleanup() {
+    val mover = AnonymousScopeVarsCleanup(this)
+    mover.visit(this)
+    printErrors(mover.result(), name)
+}
+
+
+internal fun Program.reorderStatements() {
+    val initvalueCreator = VarInitValueAndAddressOfCreator(this)
+    initvalueCreator.visit(this)
+
+    val checker = StatementReorderer(this)
+    checker.visit(this)
+}
+
+internal fun Program.addTypecasts() {
+    val caster = TypecastsAdder(this)
+    caster.visit(this)
+}
+
+internal fun Module.checkImportedValid() {
+    val checker = ImportedModuleDirectiveRemover()
+    checker.visit(this)
+    printErrors(checker.result(), name)
+}
+
+internal fun Program.checkRecursion() {
+    val checker = AstRecursionChecker(namespace)
+    checker.visit(this)
+    printErrors(checker.result(), name)
+}
+
+
+internal fun Program.checkIdentifiers() {
+    val checker = AstIdentifiersChecker(this)
+    checker.visit(this)
+
+    if(modules.map {it.name}.toSet().size != modules.size) {
+        throw FatalAstException("modules should all be unique")
+    }
+
+    printErrors(checker.result(), name)
+}

compiler/src/prog8/ast/expressions/AstExpressions.kt

@@ -0,0 +1,738 @@
+package prog8.ast.expressions
+
+import prog8.ast.*
+import prog8.ast.antlr.escape
+import prog8.ast.base.*
+import prog8.ast.processing.IAstModifyingVisitor
+import prog8.ast.processing.IAstVisitor
+import prog8.ast.statements.ArrayIndex
+import prog8.ast.statements.BuiltinFunctionStatementPlaceholder
+import prog8.ast.statements.Subroutine
+import prog8.ast.statements.VarDecl
+import prog8.compiler.target.CompilationTarget
+import prog8.functions.BuiltinFunctions
+import prog8.functions.NotConstArgumentException
+import prog8.functions.builtinFunctionReturnType
+import java.util.Objects
+import kotlin.math.abs
+
+
+val associativeOperators = setOf("+", "*", "&", "|", "^", "or", "and", "xor", "==", "!=")
+
+
+sealed class Expression: Node {
+    abstract fun constValue(program: Program): NumericLiteralValue?
+    abstract fun accept(visitor: IAstModifyingVisitor): Expression
+    abstract fun accept(visitor: IAstVisitor)
+    abstract fun referencesIdentifiers(vararg name: String): Boolean     // todo: remove this and add identifier usage tracking into CallGraph instead
+    abstract fun inferType(program: Program): InferredTypes.InferredType
+
+    infix fun isSameAs(other: Expression): Boolean {
+        if(this===other)
+            return true
+        when(this) {
+            is RegisterExpr ->
+                return (other is RegisterExpr && other.register==register)
+            is IdentifierReference ->
+                return (other is IdentifierReference && other.nameInSource==nameInSource)
+            is PrefixExpression ->
+                return (other is PrefixExpression && other.operator==operator && other.expression isSameAs expression)
+            is BinaryExpression ->
+                return (other is BinaryExpression && other.operator==operator
+                        && other.left isSameAs left
+                        && other.right isSameAs right)
+            is ArrayIndexedExpression -> {
+                return (other is ArrayIndexedExpression && other.identifier.nameInSource == identifier.nameInSource
+                        && other.arrayspec.index isSameAs arrayspec.index)
+            }
+            else -> return other==this
+        }
+    }
+}
+
+
+class PrefixExpression(val operator: String, var expression: Expression, override val position: Position) : Expression() {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        expression.linkParents(this)
+    }
+
+    override fun constValue(program: Program): NumericLiteralValue? = null
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun referencesIdentifiers(vararg name: String) = expression.referencesIdentifiers(*name)
+    override fun inferType(program: Program): InferredTypes.InferredType {
+        val inferred = expression.inferType(program)
+        return when(operator) {
+            "+" -> inferred
+            "~", "not" -> {
+                when(inferred.typeOrElse(DataType.STRUCT)) {
+                    in ByteDatatypes -> InferredTypes.knownFor(DataType.UBYTE)
+                    in WordDatatypes -> InferredTypes.knownFor(DataType.UWORD)
+                    else -> inferred
+                }
+            }
+            "-" -> {
+                when(inferred.typeOrElse(DataType.STRUCT)) {
+                    in ByteDatatypes -> InferredTypes.knownFor(DataType.BYTE)
+                    in WordDatatypes -> InferredTypes.knownFor(DataType.WORD)
+                    else -> inferred
+                }
+            }
+            else -> throw FatalAstException("weird prefix expression operator")
+        }
+    }
+
+    override fun toString(): String {
+        return "Prefix($operator $expression)"
+    }
+}
+
+class BinaryExpression(var left: Expression, var operator: String, var right: Expression, override val position: Position) : Expression() {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        left.linkParents(this)
+        right.linkParents(this)
+    }
+
+    override fun toString(): String {
+        return "[$left $operator $right]"
+    }
+
+    // binary expression should actually have been optimized away into a single value, before const value was requested...
+    override fun constValue(program: Program): NumericLiteralValue? = null
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun referencesIdentifiers(vararg name: String) = left.referencesIdentifiers(*name) || right.referencesIdentifiers(*name)
+    override fun inferType(program: Program): InferredTypes.InferredType {
+        val leftDt = left.inferType(program)
+        val rightDt = right.inferType(program)
+        return when (operator) {
+            "+", "-", "*", "**", "%", "/" -> {
+                if (!leftDt.isKnown || !rightDt.isKnown)
+                    InferredTypes.unknown()
+                else {
+                    try {
+                        InferredTypes.knownFor(commonDatatype(
+                                leftDt.typeOrElse(DataType.BYTE),
+                                rightDt.typeOrElse(DataType.BYTE),
+                                null, null).first)
+                    } catch (x: FatalAstException) {
+                        InferredTypes.unknown()
+                    }
+                }
+            }
+            "&" -> leftDt
+            "|" -> leftDt
+            "^" -> leftDt
+            "and", "or", "xor",
+            "<", ">",
+            "<=", ">=",
+            "==", "!=" -> InferredTypes.knownFor(DataType.UBYTE)
+            "<<", ">>" -> leftDt
+            else -> throw FatalAstException("resulting datatype check for invalid operator $operator")
+        }
+    }
+
+    companion object {
+        fun commonDatatype(leftDt: DataType, rightDt: DataType,
+                           left: Expression?, right: Expression?): Pair<DataType, Expression?> {
+            // byte + byte -> byte
+            // byte + word -> word
+            // word + byte -> word
+            // word + word -> word
+            // a combination with a float will be float (but give a warning about this!)
+
+            return when (leftDt) {
+                DataType.UBYTE -> {
+                    when (rightDt) {
+                        DataType.UBYTE -> Pair(DataType.UBYTE, null)
+                        DataType.BYTE -> Pair(DataType.BYTE, left)
+                        DataType.UWORD -> Pair(DataType.UWORD, left)
+                        DataType.WORD -> Pair(DataType.WORD, left)
+                        DataType.FLOAT -> Pair(DataType.FLOAT, left)
+                        else -> Pair(leftDt, null)      // non-numeric datatype
+                    }
+                }
+                DataType.BYTE -> {
+                    when (rightDt) {
+                        DataType.UBYTE -> Pair(DataType.BYTE, right)
+                        DataType.BYTE -> Pair(DataType.BYTE, null)
+                        DataType.UWORD -> Pair(DataType.WORD, left)
+                        DataType.WORD -> Pair(DataType.WORD, left)
+                        DataType.FLOAT -> Pair(DataType.FLOAT, left)
+                        else -> Pair(leftDt, null)      // non-numeric datatype
+                    }
+                }
+                DataType.UWORD -> {
+                    when (rightDt) {
+                        DataType.UBYTE -> Pair(DataType.UWORD, right)
+                        DataType.BYTE -> Pair(DataType.WORD, right)
+                        DataType.UWORD -> Pair(DataType.UWORD, null)
+                        DataType.WORD -> Pair(DataType.WORD, left)
+                        DataType.FLOAT -> Pair(DataType.FLOAT, left)
+                        else -> Pair(leftDt, null)      // non-numeric datatype
+                    }
+                }
+                DataType.WORD -> {
+                    when (rightDt) {
+                        DataType.UBYTE -> Pair(DataType.WORD, right)
+                        DataType.BYTE -> Pair(DataType.WORD, right)
+                        DataType.UWORD -> Pair(DataType.WORD, right)
+                        DataType.WORD -> Pair(DataType.WORD, null)
+                        DataType.FLOAT -> Pair(DataType.FLOAT, left)
+                        else -> Pair(leftDt, null)      // non-numeric datatype
+                    }
+                }
+                DataType.FLOAT -> {
+                    Pair(DataType.FLOAT, right)
+                }
+                else -> Pair(leftDt, null)      // non-numeric datatype
+            }
+        }
+    }
+}
+
+class ArrayIndexedExpression(var identifier: IdentifierReference,
+                             val arrayspec: ArrayIndex,
+                             override val position: Position) : Expression(), IAssignable {
+    override lateinit var parent: Node
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        identifier.linkParents(this)
+        arrayspec.linkParents(this)
+    }
+
+    override fun constValue(program: Program): NumericLiteralValue? = null
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun referencesIdentifiers(vararg name: String) = identifier.referencesIdentifiers(*name)
+
+    override fun inferType(program: Program): InferredTypes.InferredType {
+        val target = identifier.targetStatement(program.namespace)
+        if (target is VarDecl) {
+            return when (target.datatype) {
+                DataType.STR -> InferredTypes.knownFor(DataType.UBYTE)
+                in ArrayDatatypes -> InferredTypes.knownFor(ArrayElementTypes.getValue(target.datatype))
+                else -> InferredTypes.unknown()
+            }
+        }
+        return InferredTypes.unknown()
+    }
+
+    override fun toString(): String {
+        return "ArrayIndexed(ident=$identifier, arraysize=$arrayspec; pos=$position)"
+    }
+}
+
+class TypecastExpression(var expression: Expression, var type: DataType, val implicit: Boolean, override val position: Position) : Expression() {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        expression.linkParents(this)
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun referencesIdentifiers(vararg name: String) = expression.referencesIdentifiers(*name)
+    override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(type)
+    override fun constValue(program: Program): NumericLiteralValue? {
+        val cv = expression.constValue(program) ?: return null
+        return cv.cast(type)
+        // val value = RuntimeValue(cv.type, cv.asNumericValue!!).cast(type)
+        // return LiteralValue.fromNumber(value.numericValue(), value.type, position).cast(type)
+    }
+
+    override fun toString(): String {
+        return "Typecast($expression as $type)"
+    }
+}
+
+data class AddressOf(var identifier: IdentifierReference, override val position: Position) : Expression() {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        identifier.parent=this
+    }
+
+    override fun constValue(program: Program): NumericLiteralValue? = null
+    override fun referencesIdentifiers(vararg name: String) = false
+    override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(DataType.UWORD)
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+}
+
+class DirectMemoryRead(var addressExpression: Expression, override val position: Position) : Expression(), IAssignable {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        this.addressExpression.linkParents(this)
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun referencesIdentifiers(vararg name: String) = false
+    override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(DataType.UBYTE)
+    override fun constValue(program: Program): NumericLiteralValue? = null
+
+    override fun toString(): String {
+        return "DirectMemoryRead($addressExpression)"
+    }
+}
+
+class NumericLiteralValue(val type: DataType,    // only numerical types allowed
+                          val number: Number,    // can be byte, word or float depending on the type
+                          override val position: Position) : Expression() {
+    override lateinit var parent: Node
+
+    companion object {
+        fun fromBoolean(bool: Boolean, position: Position) =
+                NumericLiteralValue(DataType.UBYTE, if (bool) 1 else 0, position)
+
+        fun optimalNumeric(value: Number, position: Position): NumericLiteralValue {
+            return if(value is Double) {
+                NumericLiteralValue(DataType.FLOAT, value, position)
+            } else {
+                when (val intval = value.toInt()) {
+                    in 0..255 -> NumericLiteralValue(DataType.UBYTE, intval, position)
+                    in -128..127 -> NumericLiteralValue(DataType.BYTE, intval, position)
+                    in 0..65535 -> NumericLiteralValue(DataType.UWORD, intval, position)
+                    in -32768..32767 -> NumericLiteralValue(DataType.WORD, intval, position)
+                    else -> NumericLiteralValue(DataType.FLOAT, intval.toDouble(), position)
+                }
+            }
+        }
+
+        fun optimalInteger(value: Int, position: Position): NumericLiteralValue {
+            return when (value) {
+                in 0..255 -> NumericLiteralValue(DataType.UBYTE, value, position)
+                in -128..127 -> NumericLiteralValue(DataType.BYTE, value, position)
+                in 0..65535 -> NumericLiteralValue(DataType.UWORD, value, position)
+                in -32768..32767 -> NumericLiteralValue(DataType.WORD, value, position)
+                else -> throw FatalAstException("integer overflow: $value")
+            }
+        }
+    }
+
+    val asBooleanValue: Boolean = number.toDouble() != 0.0
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+    }
+
+    override fun referencesIdentifiers(vararg name: String) = false
+    override fun constValue(program: Program) = this
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    override fun toString(): String = "NumericLiteral(${type.name}:$number)"
+
+    override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(type)
+
+    override fun hashCode(): Int = Objects.hash(type, number)
+
+    override fun equals(other: Any?): Boolean {
+        if(other==null || other !is NumericLiteralValue)
+            return false
+        return number.toDouble()==other.number.toDouble()
+    }
+
+    operator fun compareTo(other: NumericLiteralValue): Int = number.toDouble().compareTo(other.number.toDouble())
+
+    fun cast(targettype: DataType): NumericLiteralValue {
+        if(type==targettype)
+            return this
+        val numval = number.toDouble()
+        when(type) {
+            DataType.UBYTE -> {
+                if(targettype== DataType.BYTE && numval <= 127)
+                    return NumericLiteralValue(targettype, number.toShort(), position)
+                if(targettype== DataType.WORD || targettype== DataType.UWORD)
+                    return NumericLiteralValue(targettype, number.toInt(), position)
+                if(targettype== DataType.FLOAT)
+                    return NumericLiteralValue(targettype, number.toDouble(), position)
+            }
+            DataType.BYTE -> {
+                if(targettype== DataType.UBYTE && numval >= 0)
+                    return NumericLiteralValue(targettype, number.toShort(), position)
+                if(targettype== DataType.UWORD && numval >= 0)
+                    return NumericLiteralValue(targettype, number.toInt(), position)
+                if(targettype== DataType.WORD)
+                    return NumericLiteralValue(targettype, number.toInt(), position)
+                if(targettype== DataType.FLOAT)
+                    return NumericLiteralValue(targettype, number.toDouble(), position)
+            }
+            DataType.UWORD -> {
+                if(targettype== DataType.BYTE && numval <= 127)
+                    return NumericLiteralValue(targettype, number.toShort(), position)
+                if(targettype== DataType.UBYTE && numval <= 255)
+                    return NumericLiteralValue(targettype, number.toShort(), position)
+                if(targettype== DataType.WORD && numval <= 32767)
+                    return NumericLiteralValue(targettype, number.toInt(), position)
+                if(targettype== DataType.FLOAT)
+                    return NumericLiteralValue(targettype, number.toDouble(), position)
+            }
+            DataType.WORD -> {
+                if(targettype== DataType.BYTE && numval >= -128 && numval <=127)
+                    return NumericLiteralValue(targettype, number.toShort(), position)
+                if(targettype== DataType.UBYTE && numval >= 0 && numval <= 255)
+                    return NumericLiteralValue(targettype, number.toShort(), position)
+                if(targettype== DataType.UWORD && numval >=0)
+                    return NumericLiteralValue(targettype, number.toInt(), position)
+                if(targettype== DataType.FLOAT)
+                    return NumericLiteralValue(targettype, number.toDouble(), position)
+            }
+            DataType.FLOAT -> {
+                if (targettype == DataType.BYTE && numval >= -128 && numval <=127)
+                    return NumericLiteralValue(targettype, number.toShort(), position)
+                if (targettype == DataType.UBYTE && numval >=0 && numval <= 255)
+                    return NumericLiteralValue(targettype, number.toShort(), position)
+                if (targettype == DataType.WORD && numval >= -32768 && numval <= 32767)
+                    return NumericLiteralValue(targettype, number.toInt(), position)
+                if (targettype == DataType.UWORD && numval >=0 && numval <= 65535)
+                    return NumericLiteralValue(targettype, number.toInt(), position)
+            }
+            else -> {}
+        }
+        throw ExpressionError("can't cast $type into $targettype", position)
+    }
+}
+
+class StructLiteralValue(var values: List<Expression>,
+                         override val position: Position): Expression() {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent=parent
+        values.forEach { it.linkParents(this) }
+    }
+
+    override fun constValue(program: Program): NumericLiteralValue?  = null
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun referencesIdentifiers(vararg name: String) = values.any { it.referencesIdentifiers(*name) }
+    override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(DataType.STRUCT)
+
+    override fun toString(): String {
+        return "struct{ ${values.joinToString(", ")} }"
+    }
+}
+
+private var heapIdSequence = 0   // unique ids for strings and arrays "on the heap"
+
+class StringLiteralValue(val value: String,
+                         override val position: Position) : Expression() {
+    override lateinit var parent: Node
+
+    val heapId = ++heapIdSequence
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+    }
+    override fun referencesIdentifiers(vararg name: String) = false
+    override fun constValue(program: Program): NumericLiteralValue? = null
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun toString(): String = "'${escape(value)}'"
+    override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(DataType.STR)
+    operator fun compareTo(other: StringLiteralValue): Int = value.compareTo(other.value)
+    override fun hashCode(): Int = value.hashCode()
+    override fun equals(other: Any?): Boolean {
+        if(other==null || other !is StringLiteralValue)
+            return false
+        return value==other.value
+    }
+}
+
+class ArrayLiteralValue(val type: DataType,     // only array types
+                        val value: Array<Expression>,
+                        override val position: Position) : Expression() {
+    override lateinit var parent: Node
+
+    val heapId = ++heapIdSequence
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        value.forEach {it.linkParents(this)}
+    }
+    override fun referencesIdentifiers(vararg name: String) = value.any { it.referencesIdentifiers(*name) }
+    override fun constValue(program: Program): NumericLiteralValue? = null
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun toString(): String = "$value"
+    override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(type)
+    operator fun compareTo(other: ArrayLiteralValue): Int = throw ExpressionError("cannot order compare arrays", position)
+    override fun hashCode(): Int = Objects.hash(value, type)
+    override fun equals(other: Any?): Boolean {
+        if(other==null || other !is ArrayLiteralValue)
+            return false
+        return type==other.type && value.contentEquals(other.value)
+    }
+
+    fun cast(targettype: DataType): ArrayLiteralValue? {
+        if(type==targettype)
+            return this
+        if(targettype in ArrayDatatypes) {
+            val elementType = ArrayElementTypes.getValue(targettype)
+            val castArray = value.map{
+                val num = it as? NumericLiteralValue
+                if(num==null) {
+                    // an array of UWORDs could possibly also contain AddressOfs, other stuff can't be casted
+                    if (elementType != DataType.UWORD || it !is AddressOf)
+                        return null
+                    it
+                } else {
+                    try {
+                        num.cast(elementType)
+                    } catch(x: ExpressionError) {
+                        return null
+                    }
+                }
+            }.toTypedArray()
+            return ArrayLiteralValue(targettype, castArray, position = position)
+        }
+        return null    // invalid type conversion from $this to $targettype
+    }
+}
+
+class RangeExpr(var from: Expression,
+                var to: Expression,
+                var step: Expression,
+                override val position: Position) : Expression() {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        from.linkParents(this)
+        to.linkParents(this)
+        step.linkParents(this)
+    }
+
+    override fun constValue(program: Program): NumericLiteralValue? = null
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun referencesIdentifiers(vararg name: String): Boolean  = from.referencesIdentifiers(*name) || to.referencesIdentifiers(*name)
+    override fun inferType(program: Program): InferredTypes.InferredType {
+        val fromDt=from.inferType(program)
+        val toDt=to.inferType(program)
+        return when {
+            !fromDt.isKnown || !toDt.isKnown -> InferredTypes.unknown()
+            fromDt istype DataType.UBYTE && toDt istype DataType.UBYTE -> InferredTypes.knownFor(DataType.ARRAY_UB)
+            fromDt istype DataType.UWORD && toDt istype DataType.UWORD -> InferredTypes.knownFor(DataType.ARRAY_UW)
+            fromDt istype DataType.STR && toDt istype DataType.STR -> InferredTypes.knownFor(DataType.STR)
+            fromDt istype DataType.WORD || toDt istype DataType.WORD -> InferredTypes.knownFor(DataType.ARRAY_W)
+            fromDt istype DataType.BYTE || toDt istype DataType.BYTE -> InferredTypes.knownFor(DataType.ARRAY_B)
+            else -> InferredTypes.knownFor(DataType.ARRAY_UB)
+        }
+    }
+    override fun toString(): String {
+        return "RangeExpr(from $from, to $to, step $step, pos=$position)"
+    }
+
+    fun size(): Int? {
+        val fromLv = (from as? NumericLiteralValue)
+        val toLv = (to as? NumericLiteralValue)
+        if(fromLv==null || toLv==null)
+            return null
+        return toConstantIntegerRange()?.count()
+    }
+
+    fun toConstantIntegerRange(): IntProgression? {
+        val fromVal: Int
+        val toVal: Int
+        val fromString = from as? StringLiteralValue
+        val toString = to as? StringLiteralValue
+        if(fromString!=null && toString!=null ) {
+            // string range -> int range over petscii values
+            fromVal = CompilationTarget.encodeString(fromString.value)[0].toInt()
+            toVal = CompilationTarget.encodeString(toString.value)[0].toInt()
+        } else {
+            val fromLv = from as? NumericLiteralValue
+            val toLv = to as? NumericLiteralValue
+            if(fromLv==null || toLv==null)
+                return null         // non-constant range
+            // integer range
+            fromVal = fromLv.number.toInt()
+            toVal = toLv.number.toInt()
+        }
+        val stepVal = (step as? NumericLiteralValue)?.number?.toInt() ?: 1
+        return makeRange(fromVal, toVal, stepVal)
+    }
+}
+
+internal fun makeRange(fromVal: Int, toVal: Int, stepVal: Int): IntProgression {
+    return when {
+        fromVal <= toVal -> when {
+            stepVal <= 0 -> IntRange.EMPTY
+            stepVal == 1 -> fromVal..toVal
+            else -> fromVal..toVal step stepVal
+        }
+        else -> when {
+            stepVal >= 0 -> IntRange.EMPTY
+            stepVal == -1 -> fromVal downTo toVal
+            else -> fromVal downTo toVal step abs(stepVal)
+        }
+    }
+}
+
+class RegisterExpr(val register: Register, override val position: Position) : Expression(), IAssignable {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+    }
+
+    override fun constValue(program: Program): NumericLiteralValue? = null
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun referencesIdentifiers(vararg name: String): Boolean = register.name in name
+    override fun toString(): String {
+        return "RegisterExpr(register=$register, pos=$position)"
+    }
+
+    override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(DataType.UBYTE)
+}
+
+data class IdentifierReference(val nameInSource: List<String>, override val position: Position) : Expression(), IAssignable {
+    override lateinit var parent: Node
+
+    fun targetStatement(namespace: INameScope) =
+        if(nameInSource.size==1 && nameInSource[0] in BuiltinFunctions)
+            BuiltinFunctionStatementPlaceholder(nameInSource[0], position)
+        else
+            namespace.lookup(nameInSource, this)
+
+    fun targetVarDecl(namespace: INameScope): VarDecl? = targetStatement(namespace) as? VarDecl
+    fun targetSubroutine(namespace: INameScope): Subroutine? = targetStatement(namespace) as? Subroutine
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+    }
+
+    override fun constValue(program: Program): NumericLiteralValue? {
+        val node = program.namespace.lookup(nameInSource, this)
+                ?: throw UndefinedSymbolError(this)
+        val vardecl = node as? VarDecl
+        if(vardecl==null) {
+            return null
+        } else if(vardecl.type!= VarDeclType.CONST) {
+            return null
+        }
+        return vardecl.value?.constValue(program)
+    }
+
+    override fun toString(): String {
+        return "IdentifierRef($nameInSource)"
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun referencesIdentifiers(vararg name: String): Boolean = nameInSource.last() in name
+
+    override fun inferType(program: Program): InferredTypes.InferredType {
+        val targetStmt = targetStatement(program.namespace)
+        if(targetStmt is VarDecl) {
+            return InferredTypes.knownFor(targetStmt.datatype)
+        } else {
+            throw FatalAstException("cannot get datatype from identifier reference ${this}, pos=$position")
+        }
+    }
+
+    fun memberOfStruct(namespace: INameScope) = this.targetVarDecl(namespace)?.struct
+
+    fun heapId(namespace: INameScope): Int {
+        val node = namespace.lookup(nameInSource, this) ?: throw UndefinedSymbolError(this)
+        val value = (node as? VarDecl)?.value ?: throw FatalAstException("requires a reference value")
+        return when (value) {
+            is IdentifierReference -> value.heapId(namespace)
+            is StringLiteralValue -> value.heapId
+            is ArrayLiteralValue -> value.heapId
+            else -> throw FatalAstException("requires a reference value")
+        }
+    }
+}
+
+class FunctionCall(override var target: IdentifierReference,
+                   override var args: MutableList<Expression>,
+                   override val position: Position) : Expression(), IFunctionCall {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        target.linkParents(this)
+        args.forEach { it.linkParents(this) }
+    }
+
+    override fun constValue(program: Program) = constValue(program, true)
+
+    private fun constValue(program: Program, withDatatypeCheck: Boolean): NumericLiteralValue? {
+        // if the function is a built-in function and the args are consts, should try to const-evaluate!
+        // lenghts of arrays and strings are constants that are determined at compile time!
+        if(target.nameInSource.size>1) return null
+        try {
+            var resultValue: NumericLiteralValue? = null
+            val func = BuiltinFunctions[target.nameInSource[0]]
+            if(func!=null) {
+                val exprfunc = func.constExpressionFunc
+                if(exprfunc!=null)
+                    resultValue = exprfunc(args, position, program)
+                else if(func.returntype==null)
+                    throw ExpressionError("builtin function ${target.nameInSource[0]} can't be used here because it doesn't return a value", position)
+            }
+
+            if(withDatatypeCheck) {
+                val resultDt = this.inferType(program)
+                if(resultValue==null || resultDt istype resultValue.type)
+                    return resultValue
+                throw FatalAstException("evaluated const expression result value doesn't match expected datatype $resultDt, pos=$position")
+            } else {
+                return resultValue
+            }
+        }
+        catch(x: NotConstArgumentException) {
+            // const-evaluating the builtin function call failed.
+            return null
+        }
+    }
+
+    override fun toString(): String {
+        return "FunctionCall(target=$target, pos=$position)"
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun referencesIdentifiers(vararg name: String): Boolean = target.referencesIdentifiers(*name) || args.any{it.referencesIdentifiers(*name)}
+
+    override fun inferType(program: Program): InferredTypes.InferredType {
+        val constVal = constValue(program ,false)
+        if(constVal!=null)
+            return InferredTypes.knownFor(constVal.type)
+        val stmt = target.targetStatement(program.namespace) ?: return InferredTypes.unknown()
+        when (stmt) {
+            is BuiltinFunctionStatementPlaceholder -> {
+                if(target.nameInSource[0] == "set_carry" || target.nameInSource[0]=="set_irqd" ||
+                        target.nameInSource[0] == "clear_carry" || target.nameInSource[0]=="clear_irqd") {
+                    return InferredTypes.void() // these have no return value
+                }
+                return builtinFunctionReturnType(target.nameInSource[0], this.args, program)
+            }
+            is Subroutine -> {
+                if(stmt.returntypes.isEmpty())
+                    return InferredTypes.void()     // no return value
+                if(stmt.returntypes.size==1)
+                    return InferredTypes.knownFor(stmt.returntypes[0])
+                return InferredTypes.unknown()     // has multiple return types... so not a single resulting datatype possible
+            }
+            else -> return InferredTypes.unknown()
+        }
+    }
+}

compiler/src/prog8/ast/expressions/InferredTypes.kt

@@ -0,0 +1,60 @@
+package prog8.ast.expressions
+
+import java.util.Objects
+import prog8.ast.base.DataType
+
+
+object InferredTypes {
+    class InferredType private constructor(val isUnknown: Boolean, val isVoid: Boolean, private var datatype: DataType?) {
+        init {
+            require(!(datatype!=null && (isUnknown || isVoid))) { "invalid combination of args" }
+        }
+
+        val isKnown = datatype!=null
+        fun typeOrElse(alternative: DataType) = if(isUnknown || isVoid) alternative else datatype!!
+        infix fun istype(type: DataType): Boolean = if(isUnknown || isVoid) false else this.datatype==type
+
+        companion object {
+            fun unknown() = InferredType(isUnknown = true, isVoid = false, datatype = null)
+            fun void() = InferredType(isUnknown = false, isVoid = true, datatype = null)
+            fun known(type: DataType) = InferredType(isUnknown = false, isVoid = false, datatype = type)
+        }
+
+        override fun equals(other: Any?): Boolean {
+            if(other !is InferredType)
+                return false
+            return isVoid==other.isVoid && datatype==other.datatype
+        }
+
+        override fun toString(): String {
+            return when {
+                datatype!=null -> datatype.toString()
+                isVoid -> "<void>"
+                else -> "<unknown>"
+            }
+        }
+
+        override fun hashCode(): Int = Objects.hash(isVoid, datatype)
+    }
+
+    private val unknownInstance = InferredType.unknown()
+    private val voidInstance = InferredType.void()
+    private val knownInstances = mapOf(
+            DataType.UBYTE to InferredType.known(DataType.UBYTE),
+            DataType.BYTE to InferredType.known(DataType.BYTE),
+            DataType.UWORD to InferredType.known(DataType.UWORD),
+            DataType.WORD to InferredType.known(DataType.WORD),
+            DataType.FLOAT to InferredType.known(DataType.FLOAT),
+            DataType.STR to InferredType.known(DataType.STR),
+            DataType.ARRAY_UB to InferredType.known(DataType.ARRAY_UB),
+            DataType.ARRAY_B to InferredType.known(DataType.ARRAY_B),
+            DataType.ARRAY_UW to InferredType.known(DataType.ARRAY_UW),
+            DataType.ARRAY_W to InferredType.known(DataType.ARRAY_W),
+            DataType.ARRAY_F to InferredType.known(DataType.ARRAY_F),
+            DataType.STRUCT to InferredType.known(DataType.STRUCT)
+    )
+
+    fun void() = voidInstance
+    fun unknown() = unknownInstance
+    fun knownFor(type: DataType) = knownInstances.getValue(type)
+}

compiler/src/prog8/ast/processing/AnonymousScopeVarsCleanup.kt

@@ -0,0 +1,47 @@
+package prog8.ast.processing
+
+import prog8.ast.Program
+import prog8.ast.base.AstException
+import prog8.ast.base.NameError
+import prog8.ast.statements.AnonymousScope
+import prog8.ast.statements.Statement
+import prog8.ast.statements.VarDecl
+
+class AnonymousScopeVarsCleanup(val program: Program): IAstModifyingVisitor {
+    private val checkResult: MutableList<AstException> = mutableListOf()
+    private val varsToMove: MutableMap<AnonymousScope, List<VarDecl>> = mutableMapOf()
+
+    fun result(): List<AstException> {
+        return checkResult
+    }
+
+    override fun visit(program: Program) {
+        varsToMove.clear()
+        super.visit(program)
+        for((scope, decls) in varsToMove) {
+            val sub = scope.definingSubroutine()!!
+            val existingVariables = sub.statements.filterIsInstance<VarDecl>().associateBy { it.name }
+            var conflicts = false
+            decls.forEach {
+                val existing = existingVariables[it.name]
+                if (existing!=null) {
+                    checkResult.add(NameError("variable ${it.name} already defined in subroutine ${sub.name} at ${existing.position}", it.position))
+                    conflicts = true
+                }
+            }
+            if (!conflicts) {
+                decls.forEach { scope.remove(it) }
+                sub.statements.addAll(0, decls)
+                decls.forEach { it.parent = sub }
+            }
+        }
+    }
+
+    override fun visit(scope: AnonymousScope): Statement {
+        val scope2 = super.visit(scope) as AnonymousScope
+        val vardecls = scope2.statements.filterIsInstance<VarDecl>()
+        varsToMove[scope2] = vardecls
+        return scope2
+    }
+}
+

compiler/src/prog8/ast/processing/AstIdentifiersChecker.kt

@@ -0,0 +1,395 @@
+package prog8.ast.processing
+
+import prog8.ast.INameScope
+import prog8.ast.Module
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.statements.*
+import prog8.compiler.target.CompilationTarget
+import prog8.functions.BuiltinFunctions
+
+
+internal class AstIdentifiersChecker(private val program: Program) : IAstModifyingVisitor {
+
+    private val checkResult: MutableList<AstException> = mutableListOf()
+
+    private var blocks = mutableMapOf<String, Block>()
+    private val vardeclsToAdd = mutableMapOf<INameScope, MutableList<VarDecl>>()
+
+    internal fun result(): List<AstException> {
+        return checkResult
+    }
+
+    private fun nameError(name: String, position: Position, existing: Statement) {
+        checkResult.add(NameError("name conflict '$name', also defined in ${existing.position.file} line ${existing.position.line}", position))
+    }
+
+    override fun visit(module: Module) {
+        vardeclsToAdd.clear()
+        blocks.clear()  // blocks may be redefined within a different module
+        super.visit(module)
+        // add any new vardecls to the various scopes
+        for((where, decls) in vardeclsToAdd) {
+            where.statements.addAll(0, decls)
+            decls.forEach { it.linkParents(where as Node) }
+        }
+    }
+
+    override fun visit(block: Block): Statement {
+        val existing = blocks[block.name]
+        if(existing!=null)
+            nameError(block.name, block.position, existing)
+        else
+            blocks[block.name] = block
+
+        return super.visit(block)
+    }
+
+    override fun visit(functionCall: FunctionCall): Expression {
+        if(functionCall.target.nameInSource.size==1 && functionCall.target.nameInSource[0]=="lsb") {
+            // lsb(...) is just an alias for type cast to ubyte, so replace with "... as ubyte"
+            val typecast = TypecastExpression(functionCall.args.single(), DataType.UBYTE, false, functionCall.position)
+            typecast.linkParents(functionCall.parent)
+            return super.visit(typecast)
+        }
+        return super.visit(functionCall)
+    }
+
+    override fun visit(decl: VarDecl): Statement {
+        // first, check if there are datatype errors on the vardecl
+        decl.datatypeErrors.forEach { checkResult.add(it) }
+
+        // now check the identifier
+        if(decl.name in BuiltinFunctions)
+            // the builtin functions can't be redefined
+            checkResult.add(NameError("builtin function cannot be redefined", decl.position))
+
+        if(decl.name in CompilationTarget.machine.opcodeNames)
+            checkResult.add(NameError("can't use a cpu opcode name as a symbol: '${decl.name}'", decl.position))
+
+        // is it a struct variable? then define all its struct members as mangled names,
+        //    and include the original decl as well.
+        if(decl.datatype==DataType.STRUCT) {
+            if(decl.structHasBeenFlattened)
+                return super.visit(decl)    // don't do this multiple times
+
+            if(decl.struct==null) {
+                checkResult.add(NameError("undefined struct type", decl.position))
+                return super.visit(decl)
+            }
+
+            if(decl.struct!!.statements.any { (it as VarDecl).datatype !in NumericDatatypes})
+                return super.visit(decl)     // a non-numeric member, not supported. proper error is given by AstChecker later
+
+            if(decl.value is NumericLiteralValue) {
+                checkResult.add(ExpressionError("you cannot initialize a struct using a single value", decl.position))
+                return super.visit(decl)
+            }
+
+            val decls = decl.flattenStructMembers()
+            decls.add(decl)
+            val result = AnonymousScope(decls, decl.position)
+            result.linkParents(decl.parent)
+            return result
+        }
+
+        val existing = program.namespace.lookup(listOf(decl.name), decl)
+        if (existing != null && existing !== decl)
+            nameError(decl.name, decl.position, existing)
+
+        return super.visit(decl)
+    }
+
+    override fun visit(subroutine: Subroutine): Statement {
+        if(subroutine.name in CompilationTarget.machine.opcodeNames) {
+            checkResult.add(NameError("can't use a cpu opcode name as a symbol: '${subroutine.name}'", subroutine.position))
+        } else if(subroutine.name in BuiltinFunctions) {
+            // the builtin functions can't be redefined
+            checkResult.add(NameError("builtin function cannot be redefined", subroutine.position))
+        } else {
+            // already reported elsewhere:
+            // if (subroutine.parameters.any { it.name in BuiltinFunctions })
+            //    checkResult.add(NameError("builtin function name cannot be used as parameter", subroutine.position))
+
+            val existing = program.namespace.lookup(listOf(subroutine.name), subroutine)
+            if (existing != null && existing !== subroutine)
+                nameError(subroutine.name, subroutine.position, existing)
+
+            // does the parameter redefine a variable declared elsewhere?
+            for(param in subroutine.parameters) {
+                val existingVar = subroutine.lookup(listOf(param.name), subroutine)
+                if (existingVar != null && existingVar.parent !== subroutine) {
+                    nameError(param.name, param.position, existingVar)
+                }
+            }
+
+            // check that there are no local variables, labels, or other subs that redefine the subroutine's parameters
+            val symbolsInSub = subroutine.allDefinedSymbols()
+            val namesInSub = symbolsInSub.map{ it.first }.toSet()
+            val paramNames = subroutine.parameters.map { it.name }.toSet()
+            val paramsToCheck = paramNames.intersect(namesInSub)
+            for(name in paramsToCheck) {
+                val labelOrVar = subroutine.getLabelOrVariable(name)
+                if(labelOrVar!=null && labelOrVar.position != subroutine.position)
+                    nameError(name, labelOrVar.position, subroutine)
+                val sub = subroutine.statements.singleOrNull { it is Subroutine && it.name==name}
+                if(sub!=null)
+                    nameError(name, sub.position, subroutine)
+            }
+
+            // inject subroutine params as local variables (if they're not there yet) (for non-kernel subroutines and non-asm parameters)
+            // NOTE:
+            // - numeric types BYTE and WORD and FLOAT are passed by value;
+            // - strings, arrays, matrices are passed by reference (their 16-bit address is passed as an uword parameter)
+            if(subroutine.asmAddress==null) {
+                if(subroutine.asmParameterRegisters.isEmpty()) {
+                    subroutine.parameters
+                            .filter { it.name !in namesInSub }
+                            .forEach {
+                                val vardecl = VarDecl(VarDeclType.VAR, it.type, ZeropageWish.NOT_IN_ZEROPAGE, null, it.name, null, null,
+                                        isArray = false, autogeneratedDontRemove = true, position = subroutine.position)
+                                vardecl.linkParents(subroutine)
+                                subroutine.statements.add(0, vardecl)
+                            }
+                }
+            }
+
+            if(subroutine.isAsmSubroutine && subroutine.statements.any{it !is InlineAssembly}) {
+                checkResult.add(SyntaxError("asmsub can only contain inline assembly (%asm)", subroutine.position))
+            }
+        }
+        return super.visit(subroutine)
+    }
+
+    override fun visit(label: Label): Statement {
+        if(label.name in CompilationTarget.machine.opcodeNames)
+            checkResult.add(NameError("can't use a cpu opcode name as a symbol: '${label.name}'", label.position))
+
+        if(label.name in BuiltinFunctions) {
+            // the builtin functions can't be redefined
+            checkResult.add(NameError("builtin function cannot be redefined", label.position))
+        } else {
+            val existing = program.namespace.lookup(listOf(label.name), label)
+            if (existing != null && existing !== label)
+                nameError(label.name, label.position, existing)
+        }
+        return super.visit(label)
+    }
+
+    override fun visit(forLoop: ForLoop): Statement {
+        // If the for loop has a decltype, it means to declare the loopvar inside the loop body
+        // rather than reusing an already declared loopvar from an outer scope.
+        // For loops that loop over an interable variable (instead of a range of numbers) get an
+        // additional interation count variable in their scope.
+        if(forLoop.loopRegister!=null) {
+            if(forLoop.loopRegister == Register.X)
+                printWarning("writing to the X register is dangerous, because it's used as an internal pointer", forLoop.position)
+        } else {
+            val loopVar = forLoop.loopVar
+            if (loopVar != null) {
+                val validName = forLoop.body.name.replace("<", "").replace(">", "").replace("-", "")
+                val loopvarName = "prog8_loopvar_$validName"
+                if (forLoop.iterable !is RangeExpr) {
+                    val existing = if (forLoop.body.containsNoCodeNorVars()) null else forLoop.body.lookup(listOf(loopvarName), forLoop.body.statements.first())
+                    if (existing == null) {
+                        // create loop iteration counter variable (without value, to avoid an assignment)
+                        val vardecl = VarDecl(VarDeclType.VAR, DataType.UBYTE, ZeropageWish.PREFER_ZEROPAGE, null, loopvarName, null, null,
+                                isArray = false, autogeneratedDontRemove = true, position = loopVar.position)
+                        vardecl.linkParents(forLoop.body)
+                        forLoop.body.statements.add(0, vardecl)
+                        loopVar.parent = forLoop.body   // loopvar 'is defined in the body'
+                    }
+                }
+            }
+        }
+        return super.visit(forLoop)
+    }
+
+    override fun visit(assignTarget: AssignTarget): AssignTarget {
+        if(assignTarget.register== Register.X)
+            printWarning("writing to the X register is dangerous, because it's used as an internal pointer", assignTarget.position)
+        return super.visit(assignTarget)
+    }
+
+    override fun visit(returnStmt: Return): Statement {
+        if(returnStmt.value!=null) {
+            // possibly adjust any literal values returned, into the desired returning data type
+            val subroutine = returnStmt.definingSubroutine()!!
+            if(subroutine.returntypes.size!=1)
+                return returnStmt  // mismatch in number of return values, error will be printed later.
+            val lval = returnStmt.value as? NumericLiteralValue
+            returnStmt.value = lval?.cast(subroutine.returntypes.single()) ?: returnStmt.value!!
+        }
+        return super.visit(returnStmt)
+    }
+
+    override fun visit(arrayLiteral: ArrayLiteralValue): Expression {
+        val array = super.visit(arrayLiteral)
+        if(array is ArrayLiteralValue) {
+            val vardecl = array.parent as? VarDecl
+            return if(vardecl!=null)
+                fixupArrayEltDatatypesFromVardecl(array, vardecl)
+            else {
+                // fix the datatype of the array (also on the heap) to the 'biggest' datatype in the array
+                // (we don't know the desired datatype here exactly so we guess)
+                val datatype = determineArrayDt(array.value)
+                val litval2 = array.cast(datatype)
+                if(litval2!=null) {
+                    litval2.parent = array.parent
+                    // finally, replace the literal array by a identifier reference.
+                    makeIdentifierFromRefLv(litval2)
+                } else array
+            }
+        }
+        return array
+    }
+
+    override fun visit(stringLiteral: StringLiteralValue): Expression {
+        val string = super.visit(stringLiteral)
+        if(string is StringLiteralValue) {
+            val vardecl = string.parent as? VarDecl
+            // intern the string; move it into the heap
+            if (string.value.length !in 1..255)
+                checkResult.add(ExpressionError("string literal length must be between 1 and 255", string.position))
+            return if (vardecl != null)
+                string
+            else
+                makeIdentifierFromRefLv(string)  // replace the literal string by a identifier reference.
+        }
+        return string
+    }
+
+    private fun determineArrayDt(array: Array<Expression>): DataType {
+        val datatypesInArray = array.map { it.inferType(program) }
+        require(datatypesInArray.isNotEmpty() && datatypesInArray.all { it.isKnown }) { "can't determine type of empty array" }
+        val dts = datatypesInArray.map { it.typeOrElse(DataType.STRUCT) }
+        return when {
+            DataType.FLOAT in dts -> DataType.ARRAY_F
+            DataType.WORD in dts -> DataType.ARRAY_W
+            DataType.UWORD in dts -> DataType.ARRAY_UW
+            DataType.BYTE in dts -> DataType.ARRAY_B
+            DataType.UBYTE in dts -> DataType.ARRAY_UB
+            else -> throw IllegalArgumentException("can't determine type of array")
+        }
+    }
+
+    private fun makeIdentifierFromRefLv(array: ArrayLiteralValue): IdentifierReference {
+        // a referencetype literal value that's not declared as a variable
+        // we need to introduce an auto-generated variable for this to be able to refer to the value
+        // note: if the var references the same literal value, it is not yet de-duplicated here.
+        val scope = array.definingScope()
+        val variable = VarDecl.createAuto(array)
+        return replaceWithIdentifier(variable, scope, array.parent)
+    }
+
+    private fun makeIdentifierFromRefLv(string: StringLiteralValue): IdentifierReference {
+        // a referencetype literal value that's not declared as a variable
+        // we need to introduce an auto-generated variable for this to be able to refer to the value
+        // note: if the var references the same literal value, it is not yet de-duplicated here.
+        val scope = string.definingScope()
+        val variable = VarDecl.createAuto(string)
+        return replaceWithIdentifier(variable, scope, string.parent)
+    }
+
+    private fun replaceWithIdentifier(variable: VarDecl, scope: INameScope, parent: Node): IdentifierReference {
+        val variable1 = addVarDecl(scope, variable)
+        // replace the reference literal by a identifier reference
+        val identifier = IdentifierReference(listOf(variable1.name), variable1.position)
+        identifier.parent = parent
+        return identifier
+    }
+
+    override fun visit(structDecl: StructDecl): Statement {
+        for(member in structDecl.statements){
+            val decl = member as? VarDecl
+            if(decl!=null && decl.datatype !in NumericDatatypes)
+                checkResult.add(SyntaxError("structs can only contain numerical types", decl.position))
+        }
+
+        return super.visit(structDecl)
+    }
+
+    override fun visit(expr: BinaryExpression): Expression {
+        return when {
+            expr.left is StringLiteralValue ->
+                processBinaryExprWithString(expr.left as StringLiteralValue, expr.right, expr)
+            expr.right is StringLiteralValue ->
+                processBinaryExprWithString(expr.right as StringLiteralValue, expr.left, expr)
+            else -> super.visit(expr)
+        }
+    }
+
+    private fun processBinaryExprWithString(string: StringLiteralValue, operand: Expression, expr: BinaryExpression): Expression {
+        val constvalue = operand.constValue(program)
+        if(constvalue!=null) {
+            if (expr.operator == "*") {
+                // repeat a string a number of times
+                return StringLiteralValue(string.value.repeat(constvalue.number.toInt()), expr.position)
+            }
+        }
+        if(expr.operator == "+" && operand is StringLiteralValue) {
+            // concatenate two strings
+            return StringLiteralValue("${string.value}${operand.value}", expr.position)
+        }
+        return expr
+    }
+
+    private fun addVarDecl(scope: INameScope, variable: VarDecl): VarDecl {
+        if(scope !in vardeclsToAdd)
+            vardeclsToAdd[scope] = mutableListOf()
+        val declList = vardeclsToAdd.getValue(scope)
+        val existing = declList.singleOrNull { it.name==variable.name }
+        return if(existing!=null) {
+            existing
+        } else {
+            declList.add(variable)
+            variable
+        }
+    }
+
+}
+
+internal fun fixupArrayEltDatatypes(array: ArrayLiteralValue, program: Program): ArrayLiteralValue {
+    val dts = array.value.map {it.inferType(program).typeOrElse(DataType.STRUCT)}.toSet()
+    if(dts.any { it !in NumericDatatypes }) {
+        return array
+    }
+    val dt = when {
+        DataType.FLOAT in dts -> DataType.ARRAY_F
+        DataType.WORD in dts -> DataType.ARRAY_W
+        DataType.UWORD in dts -> DataType.ARRAY_UW
+        DataType.BYTE in dts -> DataType.ARRAY_B
+        else -> DataType.ARRAY_UB
+    }
+    if(dt==array.type)
+        return array
+
+    // convert values and array type
+    val elementType = ArrayElementTypes.getValue(dt)
+    val allNumerics = array.value.all { it is NumericLiteralValue }
+    if(allNumerics) {
+        val values = array.value.map { (it as NumericLiteralValue).cast(elementType) as Expression }.toTypedArray()
+        val array2 = ArrayLiteralValue(dt, values, array.position)
+        array2.linkParents(array.parent)
+        return array2
+    }
+
+    return array
+}
+
+internal fun fixupArrayEltDatatypesFromVardecl(array: ArrayLiteralValue, vardecl: VarDecl): ArrayLiteralValue {
+    val arrayDt = array.type
+    if(arrayDt!=vardecl.datatype) {
+        // fix the datatype of the array (also on the heap) to match the vardecl
+        val cast = array.cast(vardecl.datatype)
+        if (cast != null) {
+            vardecl.value = cast
+            cast.linkParents(vardecl)
+            return cast
+        }
+        // can't be casted yet, attempt again later
+    }
+    return array
+}

compiler/src/prog8/ast/processing/AstRecursionChecker.kt

@@ -0,0 +1,117 @@
+package prog8.ast.processing
+
+import prog8.ast.INameScope
+import prog8.ast.base.AstException
+import prog8.ast.expressions.FunctionCall
+import prog8.ast.statements.FunctionCallStatement
+import prog8.ast.statements.Subroutine
+
+
+internal class AstRecursionChecker(private val namespace: INameScope) : IAstVisitor {
+    private val callGraph = DirectedGraph<INameScope>()
+
+    internal fun result(): List<AstException> {
+        val cycle = callGraph.checkForCycle()
+        if(cycle.isEmpty())
+            return emptyList()
+        val chain = cycle.joinToString(" <-- ") { "${it.name} at ${it.position}" }
+        return listOf(AstException("Program contains recursive subroutine calls, this is not supported. Recursive chain:\n (a subroutine call in) $chain"))
+    }
+
+    override fun visit(functionCallStatement: FunctionCallStatement) {
+        val scope = functionCallStatement.definingScope()
+        val targetStatement = functionCallStatement.target.targetStatement(namespace)
+        if(targetStatement!=null) {
+            val targetScope = when (targetStatement) {
+                is Subroutine -> targetStatement
+                else -> targetStatement.definingScope()
+            }
+            callGraph.add(scope, targetScope)
+        }
+        super.visit(functionCallStatement)
+    }
+
+    override fun visit(functionCall: FunctionCall) {
+        val scope = functionCall.definingScope()
+        val targetStatement = functionCall.target.targetStatement(namespace)
+        if(targetStatement!=null) {
+            val targetScope = when (targetStatement) {
+                is Subroutine -> targetStatement
+                else -> targetStatement.definingScope()
+            }
+            callGraph.add(scope, targetScope)
+        }
+        super.visit(functionCall)
+    }
+
+
+    private class DirectedGraph<VT> {
+        private val graph = mutableMapOf<VT, MutableSet<VT>>()
+        private var uniqueVertices = mutableSetOf<VT>()
+        val numVertices : Int
+            get() = uniqueVertices.size
+
+        fun add(from: VT, to: VT) {
+            var targets = graph[from]
+            if(targets==null) {
+                targets = mutableSetOf()
+                graph[from] = targets
+            }
+            targets.add(to)
+            uniqueVertices.add(from)
+            uniqueVertices.add(to)
+        }
+
+        fun print() {
+            println("#vertices: $numVertices")
+            graph.forEach { (from, to) ->
+                println("$from   CALLS:")
+                to.forEach { println("   $it") }
+            }
+            val cycle = checkForCycle()
+            if(cycle.isNotEmpty()) {
+                println("CYCLIC!  $cycle")
+            }
+        }
+
+        fun checkForCycle(): MutableList<VT> {
+            val visited = uniqueVertices.associateWith { false }.toMutableMap()
+            val recStack = uniqueVertices.associateWith { false }.toMutableMap()
+            val cycle = mutableListOf<VT>()
+            for(node in uniqueVertices) {
+                if(isCyclicUntil(node, visited, recStack, cycle))
+                    return cycle
+            }
+            return mutableListOf()
+        }
+
+        private fun isCyclicUntil(node: VT,
+                                  visited: MutableMap<VT, Boolean>,
+                                  recStack: MutableMap<VT, Boolean>,
+                                  cycleNodes: MutableList<VT>): Boolean {
+
+            if(recStack[node]==true) return true
+            if(visited[node]==true) return false
+
+            // mark current node as visited and add to recursion stack
+            visited[node] = true
+            recStack[node] = true
+
+            // recurse for all neighbours
+            val neighbors = graph[node]
+            if(neighbors!=null) {
+                for (neighbour in neighbors) {
+                    if (isCyclicUntil(neighbour, visited, recStack, cycleNodes)) {
+                        cycleNodes.add(node)
+                        return true
+                    }
+                }
+            }
+
+            // pop node from recursion stack
+            recStack[node] = false
+            return false
+        }
+    }
+
+}

compiler/src/prog8/ast/processing/IAstModifyingVisitor.kt

@@ -0,0 +1,261 @@
+package prog8.ast.processing
+
+import prog8.ast.Module
+import prog8.ast.Program
+import prog8.ast.base.FatalAstException
+import prog8.ast.expressions.*
+import prog8.ast.statements.*
+
+interface IAstModifyingVisitor {
+    fun visit(program: Program) {
+        program.modules.forEach { visit(it) }
+    }
+
+    fun visit(module: Module) {
+        module.statements = module.statements.map { it.accept(this) }.toMutableList()
+    }
+
+    fun visit(expr: PrefixExpression): Expression {
+        expr.expression = expr.expression.accept(this)
+        return expr
+    }
+
+    fun visit(expr: BinaryExpression): Expression {
+        expr.left = expr.left.accept(this)
+        expr.right = expr.right.accept(this)
+        return expr
+    }
+
+    fun visit(directive: Directive): Statement {
+        return directive
+    }
+
+    fun visit(block: Block): Statement {
+        block.statements = block.statements.map { it.accept(this) }.toMutableList()
+        return block
+    }
+
+    fun visit(decl: VarDecl): Statement {
+        decl.value = decl.value?.accept(this)
+        decl.arraysize?.accept(this)
+        return decl
+    }
+
+    fun visit(subroutine: Subroutine): Statement {
+        subroutine.statements = subroutine.statements.map { it.accept(this) }.toMutableList()
+        return subroutine
+    }
+
+    fun visit(functionCall: FunctionCall): Expression {
+        val newtarget = functionCall.target.accept(this)
+        if(newtarget is IdentifierReference)
+            functionCall.target = newtarget
+        else
+            throw FatalAstException("cannot change class of function call target")
+        functionCall.args = functionCall.args.map { it.accept(this) }.toMutableList()
+        return functionCall
+    }
+
+    fun visit(functionCallStatement: FunctionCallStatement): Statement {
+        val newtarget = functionCallStatement.target.accept(this)
+        if(newtarget is IdentifierReference)
+            functionCallStatement.target = newtarget
+        else
+            throw FatalAstException("cannot change class of function call target")
+        functionCallStatement.args = functionCallStatement.args.map { it.accept(this) }.toMutableList()
+        return functionCallStatement
+    }
+
+    fun visit(identifier: IdentifierReference): Expression {
+        // note: this is an identifier that is used in an expression.
+        // other identifiers are simply part of the other statements (such as jumps, subroutine defs etc)
+        return identifier
+    }
+
+    fun visit(jump: Jump): Statement {
+        if(jump.identifier!=null) {
+            val ident = jump.identifier.accept(this)
+            if(ident is IdentifierReference && ident!==jump.identifier) {
+                return Jump(null, ident, null, jump.position)
+            }
+        }
+        return jump
+    }
+
+    fun visit(ifStatement: IfStatement): Statement {
+        ifStatement.condition = ifStatement.condition.accept(this)
+        ifStatement.truepart = ifStatement.truepart.accept(this) as AnonymousScope
+        ifStatement.elsepart = ifStatement.elsepart.accept(this) as AnonymousScope
+        return ifStatement
+    }
+
+    fun visit(branchStatement: BranchStatement): Statement {
+        branchStatement.truepart = branchStatement.truepart.accept(this) as AnonymousScope
+        branchStatement.elsepart = branchStatement.elsepart.accept(this) as AnonymousScope
+        return branchStatement
+    }
+
+    fun visit(range: RangeExpr): Expression {
+        range.from = range.from.accept(this)
+        range.to = range.to.accept(this)
+        range.step = range.step.accept(this)
+        return range
+    }
+
+    fun visit(label: Label): Statement {
+        return label
+    }
+
+    fun visit(literalValue: NumericLiteralValue): NumericLiteralValue {
+        return literalValue
+    }
+
+    fun visit(stringLiteral: StringLiteralValue): Expression {
+        return stringLiteral
+    }
+
+    fun visit(arrayLiteral: ArrayLiteralValue): Expression {
+        for(av in arrayLiteral.value.withIndex()) {
+            val newvalue = av.value.accept(this)
+            arrayLiteral.value[av.index] = newvalue
+        }
+        return arrayLiteral
+    }
+
+    fun visit(assignment: Assignment): Statement {
+        assignment.target = assignment.target.accept(this)
+        assignment.value = assignment.value.accept(this)
+        return assignment
+    }
+
+    fun visit(postIncrDecr: PostIncrDecr): Statement {
+        postIncrDecr.target = postIncrDecr.target.accept(this)
+        return postIncrDecr
+    }
+
+    fun visit(contStmt: Continue): Statement {
+        return contStmt
+    }
+
+    fun visit(breakStmt: Break): Statement {
+        return breakStmt
+    }
+
+    fun visit(forLoop: ForLoop): Statement {
+        when(val newloopvar = forLoop.loopVar?.accept(this)) {
+            is IdentifierReference -> forLoop.loopVar = newloopvar
+            null -> forLoop.loopVar = null
+            else -> throw FatalAstException("can't change class of loopvar")
+        }
+        forLoop.iterable = forLoop.iterable.accept(this)
+        forLoop.body = forLoop.body.accept(this) as AnonymousScope
+        return forLoop
+    }
+
+    fun visit(whileLoop: WhileLoop): Statement {
+        whileLoop.condition = whileLoop.condition.accept(this)
+        whileLoop.body = whileLoop.body.accept(this) as AnonymousScope
+        return whileLoop
+    }
+
+    fun visit(repeatLoop: RepeatLoop): Statement {
+        repeatLoop.untilCondition = repeatLoop.untilCondition.accept(this)
+        repeatLoop.body = repeatLoop.body.accept(this) as AnonymousScope
+        return repeatLoop
+    }
+
+    fun visit(returnStmt: Return): Statement {
+        returnStmt.value = returnStmt.value?.accept(this)
+        return returnStmt
+    }
+
+    fun visit(arrayIndexedExpression: ArrayIndexedExpression): ArrayIndexedExpression {
+        val ident = arrayIndexedExpression.identifier.accept(this)
+        if(ident is IdentifierReference)
+            arrayIndexedExpression.identifier = ident
+        arrayIndexedExpression.arrayspec.accept(this)
+        return arrayIndexedExpression
+    }
+
+    fun visit(assignTarget: AssignTarget): AssignTarget {
+        when (val ident = assignTarget.identifier?.accept(this)) {
+            is IdentifierReference -> assignTarget.identifier = ident
+            null -> assignTarget.identifier = null
+            else -> throw FatalAstException("can't change class of assign target identifier")
+        }
+        assignTarget.arrayindexed = assignTarget.arrayindexed?.accept(this)
+        assignTarget.memoryAddress?.let { visit(it) }
+        return assignTarget
+    }
+
+    fun visit(scope: AnonymousScope): Statement {
+        scope.statements = scope.statements.map { it.accept(this) }.toMutableList()
+        return scope
+    }
+
+    fun visit(typecast: TypecastExpression): Expression {
+        typecast.expression = typecast.expression.accept(this)
+        return typecast
+    }
+
+    fun visit(memread: DirectMemoryRead): Expression {
+        memread.addressExpression = memread.addressExpression.accept(this)
+        return memread
+    }
+
+    fun visit(memwrite: DirectMemoryWrite) {
+        memwrite.addressExpression = memwrite.addressExpression.accept(this)
+    }
+
+    fun visit(addressOf: AddressOf): Expression {
+        val ident = addressOf.identifier.accept(this)
+        if(ident is IdentifierReference)
+            addressOf.identifier = ident
+        else
+            throw FatalAstException("can't change class of addressof identifier")
+        return addressOf
+    }
+
+    fun visit(inlineAssembly: InlineAssembly): Statement {
+        return inlineAssembly
+    }
+
+    fun visit(registerExpr: RegisterExpr): Expression {
+        return registerExpr
+    }
+
+    fun visit(builtinFunctionStatementPlaceholder: BuiltinFunctionStatementPlaceholder): Statement {
+        return builtinFunctionStatementPlaceholder
+    }
+
+    fun visit(nopStatement: NopStatement): Statement {
+        return nopStatement
+    }
+
+    fun visit(whenStatement: WhenStatement): Statement {
+        whenStatement.condition = whenStatement.condition.accept(this)
+        whenStatement.choices.forEach { it.accept(this) }
+        return whenStatement
+    }
+
+    fun visit(whenChoice: WhenChoice) {
+        whenChoice.values = whenChoice.values?.map { it.accept(this) }
+        val stmt = whenChoice.statements.accept(this)
+        if(stmt is AnonymousScope)
+            whenChoice.statements = stmt
+        else {
+            whenChoice.statements = AnonymousScope(mutableListOf(stmt), stmt.position)
+            whenChoice.statements.linkParents(whenChoice)
+        }
+    }
+
+    fun visit(structDecl: StructDecl): Statement {
+        structDecl.statements = structDecl.statements.map{ it.accept(this) }.toMutableList()
+        return structDecl
+    }
+
+    fun visit(structLv: StructLiteralValue): Expression {
+        structLv.values = structLv.values.map { it.accept(this) }
+        return structLv
+    }
+}

compiler/src/prog8/ast/processing/IAstVisitor.kt

@@ -0,0 +1,184 @@
+package prog8.ast.processing
+
+import prog8.ast.Module
+import prog8.ast.Program
+import prog8.ast.expressions.*
+import prog8.ast.statements.*
+
+interface IAstVisitor {
+    fun visit(program: Program) {
+        program.modules.forEach { visit(it) }
+    }
+
+    fun visit(module: Module) {
+        module.statements.forEach{ it.accept(this) }
+    }
+
+    fun visit(expr: PrefixExpression) {
+        expr.expression.accept(this)
+    }
+
+    fun visit(expr: BinaryExpression) {
+        expr.left.accept(this)
+        expr.right.accept(this)
+    }
+
+    fun visit(directive: Directive) {
+    }
+
+    fun visit(block: Block) {
+        block.statements.forEach { it.accept(this) }
+    }
+
+    fun visit(decl: VarDecl) {
+        decl.value?.accept(this)
+        decl.arraysize?.accept(this)
+    }
+
+    fun visit(subroutine: Subroutine) {
+        subroutine.statements.forEach { it.accept(this) }
+    }
+
+    fun visit(functionCall: FunctionCall) {
+        functionCall.target.accept(this)
+        functionCall.args.forEach { it.accept(this) }
+    }
+
+    fun visit(functionCallStatement: FunctionCallStatement) {
+        functionCallStatement.target.accept(this)
+        functionCallStatement.args.forEach { it.accept(this) }
+    }
+
+    fun visit(identifier: IdentifierReference) {
+    }
+
+    fun visit(jump: Jump) {
+        jump.identifier?.accept(this)
+    }
+
+    fun visit(ifStatement: IfStatement) {
+        ifStatement.condition.accept(this)
+        ifStatement.truepart.accept(this)
+        ifStatement.elsepart.accept(this)
+    }
+
+    fun visit(branchStatement: BranchStatement) {
+        branchStatement.truepart.accept(this)
+        branchStatement.elsepart.accept(this)
+    }
+
+    fun visit(range: RangeExpr) {
+        range.from.accept(this)
+        range.to.accept(this)
+        range.step.accept(this)
+    }
+
+    fun visit(label: Label) {
+    }
+
+    fun visit(numLiteral: NumericLiteralValue) {
+    }
+
+    fun visit(string: StringLiteralValue) {
+    }
+
+    fun visit(array: ArrayLiteralValue) {
+        array.value.forEach { v->v.accept(this) }
+    }
+
+    fun visit(assignment: Assignment) {
+        assignment.target.accept(this)
+        assignment.value.accept(this)
+    }
+
+    fun visit(postIncrDecr: PostIncrDecr) {
+        postIncrDecr.target.accept(this)
+    }
+
+    fun visit(contStmt: Continue) {
+    }
+
+    fun visit(breakStmt: Break) {
+    }
+
+    fun visit(forLoop: ForLoop) {
+        forLoop.loopVar?.accept(this)
+        forLoop.iterable.accept(this)
+        forLoop.body.accept(this)
+    }
+
+    fun visit(whileLoop: WhileLoop) {
+        whileLoop.condition.accept(this)
+        whileLoop.body.accept(this)
+    }
+
+    fun visit(repeatLoop: RepeatLoop) {
+        repeatLoop.untilCondition.accept(this)
+        repeatLoop.body.accept(this)
+    }
+
+    fun visit(returnStmt: Return) {
+        returnStmt.value?.accept(this)
+    }
+
+    fun visit(arrayIndexedExpression: ArrayIndexedExpression) {
+        arrayIndexedExpression.identifier.accept(this)
+        arrayIndexedExpression.arrayspec.accept(this)
+    }
+
+    fun visit(assignTarget: AssignTarget) {
+        assignTarget.arrayindexed?.accept(this)
+        assignTarget.identifier?.accept(this)
+        assignTarget.memoryAddress?.accept(this)
+    }
+
+    fun visit(scope: AnonymousScope) {
+        scope.statements.forEach { it.accept(this) }
+    }
+
+    fun visit(typecast: TypecastExpression) {
+        typecast.expression.accept(this)
+    }
+
+    fun visit(memread: DirectMemoryRead) {
+        memread.addressExpression.accept(this)
+    }
+
+    fun visit(memwrite: DirectMemoryWrite) {
+        memwrite.addressExpression.accept(this)
+    }
+
+    fun visit(addressOf: AddressOf) {
+        addressOf.identifier.accept(this)
+    }
+
+    fun visit(inlineAssembly: InlineAssembly) {
+    }
+
+    fun visit(registerExpr: RegisterExpr) {
+    }
+
+    fun visit(builtinFunctionStatementPlaceholder: BuiltinFunctionStatementPlaceholder) {
+    }
+
+    fun visit(nopStatement: NopStatement) {
+    }
+
+    fun visit(whenStatement: WhenStatement) {
+        whenStatement.condition.accept(this)
+        whenStatement.choices.forEach { it.accept(this) }
+    }
+
+    fun visit(whenChoice: WhenChoice) {
+        whenChoice.values?.forEach { it.accept(this) }
+        whenChoice.statements.accept(this)
+    }
+
+    fun visit(structDecl: StructDecl) {
+        structDecl.statements.forEach { it.accept(this) }
+    }
+
+    fun visit(structLv: StructLiteralValue) {
+        structLv.values.forEach { it.accept(this) }
+    }
+}

compiler/src/prog8/ast/processing/ImportedModuleDirectiveRemover.kt

@@ -1,18 +1,12 @@
-package prog8.ast
+package prog8.ast.processing
 
+import prog8.ast.Module
+import prog8.ast.base.SyntaxError
+import prog8.ast.base.printWarning
+import prog8.ast.statements.Directive
+import prog8.ast.statements.Statement
 
-/**
- * Checks that are specific for imported modules.
- */
-
-internal fun Module.checkImportedValid() {
-    val checker = ImportedAstChecker()
-    checker.process(this)
-    printErrors(checker.result(), name)
-}
-
-
-private class ImportedAstChecker : IAstProcessor {
+internal class ImportedModuleDirectiveRemover : IAstModifyingVisitor {
     private val checkResult: MutableList<SyntaxError> = mutableListOf()
 
     internal fun result(): List<SyntaxError> {
@@ -20,15 +14,15 @@ private class ImportedAstChecker : IAstProcessor {
     }
 
     /**
-     * Module check: most global directives don't apply for imported modules
+     * Most global directives don't apply for imported modules, so remove them
      */
-    override fun process(module: Module) {
-        super.process(module)
-        val newStatements : MutableList<IStatement> = mutableListOf()
+    override fun visit(module: Module) {
+        super.visit(module)
+        val newStatements : MutableList<Statement> = mutableListOf()
 
         val moduleLevelDirectives = listOf("%output", "%launcher", "%zeropage", "%zpreserved", "%address")
         for (sourceStmt in module.statements) {
-            val stmt = sourceStmt.process(this)
+            val stmt = sourceStmt.accept(this)
             if(stmt is Directive && stmt.parent is Module) {
                 if(stmt.directive in moduleLevelDirectives) {
                     printWarning("ignoring module directive because it was imported", stmt.position, stmt.directive)

compiler/src/prog8/ast/processing/StatementReorderer.kt

@@ -0,0 +1,258 @@
+package prog8.ast.processing
+
+import prog8.ast.*
+import prog8.ast.base.DataType
+import prog8.ast.base.FatalAstException
+import prog8.ast.base.initvarsSubName
+import prog8.ast.expressions.*
+import prog8.ast.statements.*
+
+
+private fun flattenStructAssignmentFromIdentifier(structAssignment: Assignment, program: Program): List<Assignment> {
+    val identifier = structAssignment.target.identifier!!
+    val identifierName = identifier.nameInSource.single()
+    val targetVar = identifier.targetVarDecl(program.namespace)!!
+    val struct = targetVar.struct!!
+    when (structAssignment.value) {
+        is IdentifierReference -> {
+            val sourceVar = (structAssignment.value as IdentifierReference).targetVarDecl(program.namespace)!!
+            if (sourceVar.struct == null)
+                throw FatalAstException("can only assign arrays or structs to structs")
+            // struct memberwise copy
+            val sourceStruct = sourceVar.struct!!
+            if(sourceStruct!==targetVar.struct) {
+                // structs are not the same in assignment
+                return listOf()     // error will be printed elsewhere
+            }
+            return struct.statements.zip(sourceStruct.statements).map { member ->
+                val targetDecl = member.first as VarDecl
+                val sourceDecl = member.second as VarDecl
+                if(targetDecl.name != sourceDecl.name)
+                    throw FatalAstException("struct member mismatch")
+                val mangled = mangledStructMemberName(identifierName, targetDecl.name)
+                val idref = IdentifierReference(listOf(mangled), structAssignment.position)
+                val sourcemangled = mangledStructMemberName(sourceVar.name, sourceDecl.name)
+                val sourceIdref = IdentifierReference(listOf(sourcemangled), structAssignment.position)
+                val assign = Assignment(AssignTarget(null, idref, null, null, structAssignment.position),
+                        null, sourceIdref, member.second.position)
+                assign.linkParents(structAssignment)
+                assign
+            }
+        }
+        is StructLiteralValue -> {
+            throw IllegalArgumentException("not going to flatten a structLv assignment here")
+        }
+        else -> throw FatalAstException("strange struct value")
+    }
+}
+
+
+internal class StatementReorderer(private val program: Program): IAstModifyingVisitor {
+    // Reorders the statements in a way the compiler needs.
+    // - 'main' block must be the very first statement UNLESS it has an address set.
+    // - blocks are ordered by address, where blocks without address are put at the end.
+    // - in every scope:
+    //      -- the directives '%output', '%launcher', '%zeropage', '%zpreserved', '%address' and '%option' will come first.
+    //      -- all vardecls then follow.
+    //      -- the remaining statements then follow in their original order.
+    //
+    // - the 'start' subroutine in the 'main' block will be moved to the top immediately following the directives.
+    // - all other subroutines will be moved to the end of their block.
+    // - sorts the choices in when statement.
+
+    private val directivesToMove = setOf("%output", "%launcher", "%zeropage", "%zpreserved", "%address", "%option")
+
+    private val addReturns = mutableListOf<Pair<INameScope, Int>>()
+
+    override fun visit(module: Module) {
+        addReturns.clear()
+        super.visit(module)
+
+        val (blocks, other) = module.statements.partition { it is Block }
+        module.statements = other.asSequence().plus(blocks.sortedBy { (it as Block).address ?: Int.MAX_VALUE }).toMutableList()
+
+        // make sure user-defined blocks come BEFORE library blocks, and move the "main" block to the top of everything
+        val nonLibraryBlocks = module.statements.withIndex()
+                .filter { it.value is Block && !(it.value as Block).isInLibrary }
+                .map { it.index to it.value }
+                .reversed()
+        for(nonLibBlock in nonLibraryBlocks)
+            module.statements.removeAt(nonLibBlock.first)
+        for(nonLibBlock in nonLibraryBlocks)
+            module.statements.add(0, nonLibBlock.second)
+        val mainBlock = module.statements.singleOrNull { it is Block && it.name=="main" }
+        if(mainBlock!=null && (mainBlock as Block).address==null) {
+            module.remove(mainBlock)
+            module.statements.add(0, mainBlock)
+        }
+
+        val varDecls = module.statements.filterIsInstance<VarDecl>()
+        module.statements.removeAll(varDecls)
+        module.statements.addAll(0, varDecls)
+
+        val directives = module.statements.filter {it is Directive && it.directive in directivesToMove}
+        module.statements.removeAll(directives)
+        module.statements.addAll(0, directives)
+
+        for(pos in addReturns) {
+            println(pos)
+            val returnStmt = Return(null, pos.first.position)
+            returnStmt.linkParents(pos.first as Node)
+            pos.first.statements.add(pos.second, returnStmt)
+        }
+    }
+
+    override fun visit(block: Block): Statement {
+
+        val subroutines = block.statements.filterIsInstance<Subroutine>()
+        var numSubroutinesAtEnd = 0
+        // move all subroutines to the end of the block
+        for (subroutine in subroutines) {
+            if(subroutine.name!="start" || block.name!="main") {
+                block.remove(subroutine)
+                block.statements.add(subroutine)
+            }
+            numSubroutinesAtEnd++
+        }
+        // move the "start" subroutine to the top
+        if(block.name=="main") {
+            block.statements.singleOrNull { it is Subroutine && it.name == "start" } ?.let {
+                block.remove(it)
+                block.statements.add(0, it)
+                numSubroutinesAtEnd--
+            }
+        }
+
+        // make sure there is a 'return' in front of the first subroutine
+        // (if it isn't the first statement in the block itself, and isn't the program's entrypoint)
+        if(numSubroutinesAtEnd>0 && block.statements.size > (numSubroutinesAtEnd+1)) {
+            val firstSub = block.statements[block.statements.size - numSubroutinesAtEnd] as Subroutine
+            if(firstSub.name != "start" && block.name != "main") {
+                val stmtBeforeFirstSub = block.statements[block.statements.size - numSubroutinesAtEnd - 1]
+                if (stmtBeforeFirstSub !is Return
+                        && stmtBeforeFirstSub !is Jump
+                        && stmtBeforeFirstSub !is Subroutine
+                        && stmtBeforeFirstSub !is BuiltinFunctionStatementPlaceholder) {
+                    val ret = Return(null, stmtBeforeFirstSub.position)
+                    ret.linkParents(block)
+                    block.statements.add(block.statements.size - numSubroutinesAtEnd, ret)
+                }
+            }
+        }
+
+        val varDecls = block.statements.filterIsInstance<VarDecl>()
+        block.statements.removeAll(varDecls)
+        block.statements.addAll(0, varDecls)
+        val directives = block.statements.filter {it is Directive && it.directive in directivesToMove}
+        block.statements.removeAll(directives)
+        block.statements.addAll(0, directives)
+        block.linkParents(block.parent)
+
+        // create subroutine that initializes the block's variables (if any)
+        val varInits = block.statements.withIndex().filter { it.value is VariableInitializationAssignment }
+        if(varInits.isNotEmpty()) {
+            val statements = varInits.map{it.value}.toMutableList()
+            val varInitSub = Subroutine(initvarsSubName, emptyList(), emptyList(), emptyList(), emptyList(),
+                    emptySet(), null, false, statements, block.position)
+            varInitSub.keepAlways = true
+            varInitSub.linkParents(block)
+            block.statements.add(varInitSub)
+
+            // remove the varinits from the block's statements
+            for(index in varInits.map{it.index}.reversed())
+                block.statements.removeAt(index)
+        }
+
+        return super.visit(block)
+    }
+
+    override fun visit(subroutine: Subroutine): Statement {
+        super.visit(subroutine)
+
+        val scope = subroutine.definingScope()
+        if(scope is Subroutine) {
+            for(stmt in scope.statements.withIndex()) {
+                if(stmt.index>0 && stmt.value===subroutine) {
+                    val precedingStmt = scope.statements[stmt.index-1]
+                    if(precedingStmt !is Jump && precedingStmt !is Subroutine) {
+                        // insert a return statement before a nested subroutine, to avoid falling trough inside the subroutine
+                        addReturns.add(Pair(scope, stmt.index))
+                    }
+                }
+            }
+        }
+
+        val varDecls = subroutine.statements.filterIsInstance<VarDecl>()
+        subroutine.statements.removeAll(varDecls)
+        subroutine.statements.addAll(0, varDecls)
+        val directives = subroutine.statements.filter {it is Directive && it.directive in directivesToMove}
+        subroutine.statements.removeAll(directives)
+        subroutine.statements.addAll(0, directives)
+
+        if(subroutine.returntypes.isEmpty()) {
+            // add the implicit return statement at the end (if it's not there yet), but only if it's not a kernel routine.
+            // and if an assembly block doesn't contain a rts/rti
+            if(subroutine.asmAddress==null && subroutine.amountOfRtsInAsm()==0) {
+                if (subroutine.statements.lastOrNull {it !is VarDecl } !is Return) {
+                    val returnStmt = Return(null, subroutine.position)
+                    returnStmt.linkParents(subroutine)
+                    subroutine.statements.add(returnStmt)
+                }
+            }
+        }
+
+        return subroutine
+    }
+
+    override fun visit(assignment: Assignment): Statement {
+        val assg = super.visit(assignment)
+        if(assg !is Assignment)
+            return assg
+
+        // see if a typecast is needed to convert the value's type into the proper target type
+        val valueItype = assg.value.inferType(program)
+        val targetItype = assg.target.inferType(program, assg)
+
+        if(targetItype.isKnown && valueItype.isKnown) {
+            val targettype = targetItype.typeOrElse(DataType.STRUCT)
+            val valuetype = valueItype.typeOrElse(DataType.STRUCT)
+
+            // struct assignments will be flattened (if it's not a struct literal)
+            if (valuetype == DataType.STRUCT && targettype == DataType.STRUCT) {
+                if (assg.value is StructLiteralValue)
+                    return assg  // do NOT flatten it at this point!! (the compiler will take care if it, later, if needed)
+
+                val assignments = flattenStructAssignmentFromIdentifier(assg, program)    //   'structvar1 = structvar2'
+                return if (assignments.isEmpty()) {
+                    // something went wrong (probably incompatible struct types)
+                    // we'll get an error later from the AstChecker
+                    assg
+                } else {
+                    val scope = AnonymousScope(assignments.toMutableList(), assg.position)
+                    scope.linkParents(assg.parent)
+                    scope
+                }
+            }
+        }
+
+        if(assg.aug_op!=null) {
+            // transform augmented assg into normal assg so we have one case less to deal with later
+            val newTarget: Expression =
+                    when {
+                        assg.target.register != null -> RegisterExpr(assg.target.register!!, assg.target.position)
+                        assg.target.identifier != null -> assg.target.identifier!!
+                        assg.target.arrayindexed != null -> assg.target.arrayindexed!!
+                        assg.target.memoryAddress != null -> DirectMemoryRead(assg.target.memoryAddress!!.addressExpression, assg.value.position)
+                        else -> throw FatalAstException("strange assg")
+                    }
+
+            val expression = BinaryExpression(newTarget, assg.aug_op.substringBeforeLast('='), assg.value, assg.position)
+            expression.linkParents(assg.parent)
+            val convertedAssignment = Assignment(assg.target, null, expression, assg.position)
+            convertedAssignment.linkParents(assg.parent)
+            return super.visit(convertedAssignment)
+        }
+
+        return assg
+    }
+}

compiler/src/prog8/ast/processing/TypecastsAdder.kt

@@ -0,0 +1,198 @@
+package prog8.ast.processing
+
+import prog8.ast.IFunctionCall
+import prog8.ast.INameScope
+import prog8.ast.Program
+import prog8.ast.base.DataType
+import prog8.ast.base.FatalAstException
+import prog8.ast.base.printWarning
+import prog8.ast.expressions.*
+import prog8.ast.statements.*
+import prog8.functions.BuiltinFunctions
+
+
+internal class TypecastsAdder(private val program: Program): IAstModifyingVisitor {
+    // Make sure any value assignments get the proper type casts if needed to cast them into the target variable's type.
+    // (this includes function call arguments)
+
+    override fun visit(expr: BinaryExpression): Expression {
+        val expr2 = super.visit(expr)
+        if(expr2 !is BinaryExpression)
+            return expr2
+        val leftDt = expr2.left.inferType(program)
+        val rightDt = expr2.right.inferType(program)
+        if(leftDt.isKnown && rightDt.isKnown && leftDt!=rightDt) {
+            // determine common datatype and add typecast as required to make left and right equal types
+            val (commonDt, toFix) = BinaryExpression.commonDatatype(leftDt.typeOrElse(DataType.STRUCT), rightDt.typeOrElse(DataType.STRUCT), expr2.left, expr2.right)
+            if(toFix!=null) {
+                when {
+                    toFix===expr2.left -> {
+                        expr2.left = TypecastExpression(expr2.left, commonDt, true, expr2.left.position)
+                        expr2.left.linkParents(expr2)
+                    }
+                    toFix===expr2.right -> {
+                        expr2.right = TypecastExpression(expr2.right, commonDt, true, expr2.right.position)
+                        expr2.right.linkParents(expr2)
+                    }
+                    else -> throw FatalAstException("confused binary expression side")
+                }
+            }
+        }
+        return expr2
+    }
+
+    override fun visit(assignment: Assignment): Statement {
+        val assg = super.visit(assignment)
+        if(assg !is Assignment)
+            return assg
+
+        // see if a typecast is needed to convert the value's type into the proper target type
+        val valueItype = assg.value.inferType(program)
+        val targetItype = assg.target.inferType(program, assg)
+
+        if(targetItype.isKnown && valueItype.isKnown) {
+            val targettype = targetItype.typeOrElse(DataType.STRUCT)
+            val valuetype = valueItype.typeOrElse(DataType.STRUCT)
+            if (valuetype != targettype) {
+                if (valuetype isAssignableTo targettype) {
+                    assg.value = TypecastExpression(assg.value, targettype, true, assg.value.position)
+                    assg.value.linkParents(assg)
+                }
+                // if they're not assignable, we'll get a proper error later from the AstChecker
+            }
+        }
+        return assg
+    }
+
+    override fun visit(functionCallStatement: FunctionCallStatement): Statement {
+        checkFunctionCallArguments(functionCallStatement, functionCallStatement.definingScope())
+        return super.visit(functionCallStatement)
+    }
+
+    override fun visit(functionCall: FunctionCall): Expression {
+        checkFunctionCallArguments(functionCall, functionCall.definingScope())
+        return super.visit(functionCall)
+    }
+
+    private fun checkFunctionCallArguments(call: IFunctionCall, scope: INameScope) {
+        // see if a typecast is needed to convert the arguments into the required parameter's type
+        when(val sub = call.target.targetStatement(scope)) {
+            is Subroutine -> {
+                for(arg in sub.parameters.zip(call.args.withIndex())) {
+                    val argItype = arg.second.value.inferType(program)
+                    if(argItype.isKnown) {
+                        val argtype = argItype.typeOrElse(DataType.STRUCT)
+                        val requiredType = arg.first.type
+                        if (requiredType != argtype) {
+                            if (argtype isAssignableTo requiredType) {
+                                val typecasted = TypecastExpression(arg.second.value, requiredType, true, arg.second.value.position)
+                                typecasted.linkParents(arg.second.value.parent)
+                                call.args[arg.second.index] = typecasted
+                            }
+                            // if they're not assignable, we'll get a proper error later from the AstChecker
+                        }
+                    }
+                }
+            }
+            is BuiltinFunctionStatementPlaceholder -> {
+                val func = BuiltinFunctions.getValue(sub.name)
+                if(func.pure) {
+                    // non-pure functions don't get automatic typecasts because sometimes they act directly on their parameters
+                    for (arg in func.parameters.zip(call.args.withIndex())) {
+                        val argItype = arg.second.value.inferType(program)
+                        if (argItype.isKnown) {
+                            val argtype = argItype.typeOrElse(DataType.STRUCT)
+                            if (arg.first.possibleDatatypes.any { argtype == it })
+                                continue
+                            for (possibleType in arg.first.possibleDatatypes) {
+                                if (argtype isAssignableTo possibleType) {
+                                    val typecasted = TypecastExpression(arg.second.value, possibleType, true, arg.second.value.position)
+                                    typecasted.linkParents(arg.second.value.parent)
+                                    call.args[arg.second.index] = typecasted
+                                    break
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+            null -> {}
+            else -> throw FatalAstException("call to something weird $sub   ${call.target}")
+        }
+    }
+
+    override fun visit(typecast: TypecastExpression): Expression {
+        // warn about any implicit type casts to Float, because that may not be intended
+        if(typecast.implicit && typecast.type in setOf(DataType.FLOAT, DataType.ARRAY_F)) {
+            printWarning("byte or word value implicitly converted to float. Suggestion: use explicit cast as float, a float number, or revert to integer arithmetic", typecast.position)
+        }
+        return super.visit(typecast)
+    }
+
+    override fun visit(memread: DirectMemoryRead): Expression {
+        // make sure the memory address is an uword
+        val dt = memread.addressExpression.inferType(program)
+        if(dt.isKnown && dt.typeOrElse(DataType.UWORD)!=DataType.UWORD) {
+            val literaladdr = memread.addressExpression as? NumericLiteralValue
+            if(literaladdr!=null) {
+                memread.addressExpression = literaladdr.cast(DataType.UWORD)
+            } else {
+                memread.addressExpression = TypecastExpression(memread.addressExpression, DataType.UWORD, true, memread.addressExpression.position)
+                memread.addressExpression.parent = memread
+            }
+        }
+        return super.visit(memread)
+    }
+
+    override fun visit(memwrite: DirectMemoryWrite) {
+        val dt = memwrite.addressExpression.inferType(program)
+        if(dt.isKnown && dt.typeOrElse(DataType.UWORD)!=DataType.UWORD) {
+            val literaladdr = memwrite.addressExpression as? NumericLiteralValue
+            if(literaladdr!=null) {
+                memwrite.addressExpression = literaladdr.cast(DataType.UWORD)
+            } else {
+                memwrite.addressExpression = TypecastExpression(memwrite.addressExpression, DataType.UWORD, true, memwrite.addressExpression.position)
+                memwrite.addressExpression.parent = memwrite
+            }
+        }
+        super.visit(memwrite)
+    }
+
+    override fun visit(structLv: StructLiteralValue): Expression {
+        val litval = super.visit(structLv)
+        if(litval !is StructLiteralValue)
+            return litval
+
+        val decl = litval.parent as? VarDecl
+        if(decl != null) {
+            val struct = decl.struct
+            if(struct != null) {
+                addTypecastsIfNeeded(litval, struct)
+            }
+        } else {
+            val assign = litval.parent as? Assignment
+            if (assign != null) {
+                val decl2 = assign.target.identifier?.targetVarDecl(program.namespace)
+                if(decl2 != null) {
+                    val struct = decl2.struct
+                    if(struct != null) {
+                        addTypecastsIfNeeded(litval, struct)
+                    }
+                }
+            }
+        }
+
+        return litval
+    }
+
+    private fun addTypecastsIfNeeded(structLv: StructLiteralValue, struct: StructDecl) {
+        structLv.values = struct.statements.zip(structLv.values).map {
+            val memberDt = (it.first as VarDecl).datatype
+            val valueDt = it.second.inferType(program)
+            if (valueDt.typeOrElse(memberDt) != memberDt)
+                TypecastExpression(it.second, memberDt, true, it.second.position)
+            else
+                it.second
+        }
+    }
+}

compiler/src/prog8/ast/processing/VarInitValueAndAddressOfCreator.kt

@@ -0,0 +1,156 @@
+package prog8.ast.processing
+
+import prog8.ast.INameScope
+import prog8.ast.Module
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.statements.*
+import prog8.compiler.CompilerException
+import prog8.functions.BuiltinFunctions
+import prog8.functions.FunctionSignature
+
+
+internal class VarInitValueAndAddressOfCreator(private val program: Program): IAstModifyingVisitor {
+    // For VarDecls that declare an initialization value:
+    // Replace the vardecl with an assignment (to set the initial value),
+    // and add a new vardecl with the default constant value of that type (usually zero) to the scope.
+    // This makes sure the variables get reset to the intended value on a next run of the program.
+    // Variable decls without a value don't get this treatment, which means they retain the last
+    // value they had when restarting the program.
+    // This is done in a separate step because it interferes with the namespace lookup of symbols
+    // in other ast processors.
+
+    // Also takes care to insert AddressOf (&) expression where required (string params to a UWORD function param etc).
+
+    private val vardeclsToAdd = mutableMapOf<INameScope, MutableList<VarDecl>>()
+
+    override fun visit(module: Module) {
+        vardeclsToAdd.clear()
+        super.visit(module)
+        // add any new vardecls to the various scopes
+        for((where, decls) in vardeclsToAdd) {
+            where.statements.addAll(0, decls)
+            decls.forEach { it.linkParents(where as Node) }
+        }
+    }
+
+    override fun visit(decl: VarDecl): Statement {
+        super.visit(decl)
+
+        if(decl.isArray && decl.value==null) {
+            // array datatype without initialization value, add list of zeros
+            val arraysize = decl.arraysize!!.size()!!
+            val array = ArrayLiteralValue(decl.datatype,
+                    Array(arraysize) { NumericLiteralValue.optimalInteger(0, decl.position) },
+                    decl.position)
+            decl.value = array
+        }
+
+        if(decl.type!= VarDeclType.VAR || decl.value==null)
+            return decl
+
+        if(decl.datatype in NumericDatatypes) {
+            val scope = decl.definingScope()
+            addVarDecl(scope, decl.asDefaultValueDecl(null))
+            val declvalue = decl.value!!
+            val value =
+                    if(declvalue is NumericLiteralValue)
+                        declvalue.cast(decl.datatype)
+                    else
+                        declvalue
+            val identifierName = listOf(decl.name)    // this was: (scoped name) decl.scopedname.split(".")
+            return VariableInitializationAssignment(
+                    AssignTarget(null, IdentifierReference(identifierName, decl.position), null, null, decl.position),
+                    null,
+                    value,
+                    decl.position
+            )
+        }
+
+        return decl
+    }
+
+    override fun visit(functionCall: FunctionCall): Expression {
+        var parentStatement: Node = functionCall
+        while(parentStatement !is Statement)
+            parentStatement = parentStatement.parent
+        val targetStatement = functionCall.target.targetSubroutine(program.namespace)
+        if(targetStatement!=null) {
+            addAddressOfExprIfNeeded(targetStatement, functionCall.args, parentStatement)
+        } else {
+            val builtinFunc = BuiltinFunctions[functionCall.target.nameInSource.joinToString (".")]
+            if(builtinFunc!=null)
+                addAddressOfExprIfNeededForBuiltinFuncs(builtinFunc, functionCall.args, parentStatement)
+        }
+        return functionCall
+    }
+
+    override fun visit(functionCallStatement: FunctionCallStatement): Statement {
+        val targetStatement = functionCallStatement.target.targetSubroutine(program.namespace)
+        if(targetStatement!=null) {
+            addAddressOfExprIfNeeded(targetStatement, functionCallStatement.args, functionCallStatement)
+        } else {
+            val builtinFunc = BuiltinFunctions[functionCallStatement.target.nameInSource.joinToString (".")]
+            if(builtinFunc!=null)
+                addAddressOfExprIfNeededForBuiltinFuncs(builtinFunc, functionCallStatement.args, functionCallStatement)
+        }
+        return functionCallStatement
+    }
+
+    private fun addAddressOfExprIfNeeded(subroutine: Subroutine, arglist: MutableList<Expression>, parent: Statement) {
+        // functions that accept UWORD and are given an array type, or string, will receive the AddressOf (memory location) of that value instead.
+        for(argparam in subroutine.parameters.withIndex().zip(arglist)) {
+            if(argparam.first.value.type==DataType.UWORD || argparam.first.value.type == DataType.STR) {
+                if(argparam.second is AddressOf)
+                    continue
+                val idref = argparam.second as? IdentifierReference
+                val strvalue = argparam.second as? StringLiteralValue
+                if(idref!=null) {
+                    val variable = idref.targetVarDecl(program.namespace)
+                    if(variable!=null && variable.datatype in IterableDatatypes) {
+                        val pointerExpr = AddressOf(idref, idref.position)
+                        pointerExpr.linkParents(arglist[argparam.first.index].parent)
+                        arglist[argparam.first.index] = pointerExpr
+                    }
+                }
+                else if(strvalue!=null) {
+                    // add a vardecl so that the autovar can be resolved in later lookups
+                    val variable = VarDecl.createAuto(strvalue)
+                    addVarDecl(strvalue.definingScope(), variable)
+                    // replace the argument with &autovar
+                    val autoHeapvarRef = IdentifierReference(listOf(variable.name), strvalue.position)
+                    val pointerExpr = AddressOf(autoHeapvarRef, strvalue.position)
+                    pointerExpr.linkParents(arglist[argparam.first.index].parent)
+                    arglist[argparam.first.index] = pointerExpr
+                }
+            }
+        }
+    }
+
+    private fun addAddressOfExprIfNeededForBuiltinFuncs(signature: FunctionSignature, args: MutableList<Expression>, parent: Statement) {
+        // val paramTypesForAddressOf = PassByReferenceDatatypes + DataType.UWORD
+        for(arg in args.withIndex().zip(signature.parameters)) {
+            val argvalue = arg.first.value
+            val argDt = argvalue.inferType(program)
+            if(argDt.typeOrElse(DataType.UBYTE) in PassByReferenceDatatypes && DataType.UWORD in arg.second.possibleDatatypes) {
+                if(argvalue !is IdentifierReference)
+                    throw CompilerException("pass-by-reference parameter isn't an identifier? $argvalue")
+                val addrOf = AddressOf(argvalue, argvalue.position)
+                args[arg.first.index] = addrOf
+                addrOf.linkParents(parent)
+            }
+        }
+    }
+
+
+    private fun addVarDecl(scope: INameScope, variable: VarDecl) {
+        if(scope !in vardeclsToAdd)
+            vardeclsToAdd[scope] = mutableListOf()
+        val declList = vardeclsToAdd.getValue(scope)
+        if(declList.all{it.name!=variable.name})
+            declList.add(variable)
+    }
+
+}

compiler/src/prog8/ast/statements/AstStatements.kt

@@ -0,0 +1,787 @@
+package prog8.ast.statements
+
+import prog8.ast.*
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.processing.IAstModifyingVisitor
+import prog8.ast.processing.IAstVisitor
+
+
+sealed class Statement : Node {
+    abstract fun accept(visitor: IAstModifyingVisitor) : Statement
+    abstract fun accept(visitor: IAstVisitor)
+    fun makeScopedName(name: String): String {
+        // easy way out is to always return the full scoped name.
+        // it would be nicer to find only the minimal prefixed scoped name, but that's too much hassle for now.
+        // and like this, we can cache the name even,
+        // like in a lazy property on the statement object itself (label, subroutine, vardecl)
+        val scope = mutableListOf<String>()
+        var statementScope = this.parent
+        while(statementScope !is ParentSentinel && statementScope !is Module) {
+            if(statementScope is INameScope) {
+                scope.add(0, statementScope.name)
+            }
+            statementScope = statementScope.parent
+        }
+        if(name.isNotEmpty())
+            scope.add(name)
+        return scope.joinToString(".")
+    }
+
+    abstract val expensiveToInline: Boolean
+
+    fun definingBlock(): Block {
+        if(this is Block)
+            return this
+        return findParentNode<Block>(this)!!
+    }
+}
+
+class BuiltinFunctionStatementPlaceholder(val name: String, override val position: Position) : Statement() {
+    override var parent: Node = ParentSentinel
+    override fun linkParents(parent: Node) {}
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun definingScope(): INameScope = BuiltinFunctionScopePlaceholder
+    override val expensiveToInline = false
+}
+
+data class RegisterOrStatusflag(val registerOrPair: RegisterOrPair?, val statusflag: Statusflag?, val stack: Boolean)
+
+class Block(override val name: String,
+            val address: Int?,
+            override var statements: MutableList<Statement>,
+            val isInLibrary: Boolean,
+            override val position: Position) : Statement(), INameScope {
+    override lateinit var parent: Node
+    override val expensiveToInline
+        get() = statements.any { it.expensiveToInline }
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        statements.forEach {it.linkParents(this)}
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    override fun toString(): String {
+        return "Block(name=$name, address=$address, ${statements.size} statements)"
+    }
+
+    fun options() = statements.filter { it is Directive && it.directive == "%option" }.flatMap { (it as Directive).args }.map {it.name!!}.toSet()
+}
+
+data class Directive(val directive: String, val args: List<DirectiveArg>, override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline = false
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        args.forEach{it.linkParents(this)}
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+}
+
+data class DirectiveArg(val str: String?, val name: String?, val int: Int?, override val position: Position) : Node {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+    }
+}
+
+data class Label(val name: String, override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline = false
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    override fun toString(): String {
+        return "Label(name=$name, pos=$position)"
+    }
+}
+
+open class Return(var value: Expression?, override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline = value!=null && value !is NumericLiteralValue
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        value?.linkParents(this)
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    override fun toString(): String {
+        return "Return($value, pos=$position)"
+    }
+}
+
+class ReturnFromIrq(override val position: Position) : Return(null, position) {
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    override fun toString(): String {
+        return "ReturnFromIrq(pos=$position)"
+    }
+}
+
+class Continue(override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline = false
+
+    override fun linkParents(parent: Node) {
+        this.parent=parent
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+}
+
+class Break(override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline = false
+
+    override fun linkParents(parent: Node) {
+        this.parent=parent
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+}
+
+
+enum class ZeropageWish {
+    REQUIRE_ZEROPAGE,
+    PREFER_ZEROPAGE,
+    DONTCARE,
+    NOT_IN_ZEROPAGE
+}
+
+class VarDecl(val type: VarDeclType,
+              private val declaredDatatype: DataType,
+              val zeropage: ZeropageWish,
+              var arraysize: ArrayIndex?,
+              val name: String,
+              private val structName: String?,
+              var value: Expression?,
+              val isArray: Boolean,
+              val autogeneratedDontRemove: Boolean,
+              override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    var struct: StructDecl? = null        // set later (because at parse time, we only know the name)
+        private set
+    var structHasBeenFlattened = false      // set later
+        private set
+
+    override val expensiveToInline
+            get() = value!=null && value !is NumericLiteralValue
+
+    // prefix for literal values that are turned into a variable on the heap
+
+    companion object {
+        private var autoHeapValueSequenceNumber = 0
+
+        fun createAuto(string: StringLiteralValue): VarDecl {
+            val autoVarName = "auto_heap_value_${++autoHeapValueSequenceNumber}"
+            return VarDecl(VarDeclType.VAR, DataType.STR, ZeropageWish.NOT_IN_ZEROPAGE, null, autoVarName, null, string,
+                        isArray = false, autogeneratedDontRemove = true, position = string.position)
+        }
+
+        fun createAuto(array: ArrayLiteralValue): VarDecl {
+            val autoVarName = "auto_heap_value_${++autoHeapValueSequenceNumber}"
+            val declaredType = ArrayElementTypes.getValue(array.type)
+            val arraysize = ArrayIndex.forArray(array)
+            return VarDecl(VarDeclType.VAR, declaredType, ZeropageWish.NOT_IN_ZEROPAGE, arraysize, autoVarName, null, array,
+                    isArray = true, autogeneratedDontRemove = true, position = array.position)
+        }
+    }
+
+    val datatypeErrors = mutableListOf<SyntaxError>()       // don't crash at init time, report them in the AstChecker
+    val datatype =
+            if (!isArray) declaredDatatype
+            else when (declaredDatatype) {
+                DataType.UBYTE -> DataType.ARRAY_UB
+                DataType.BYTE -> DataType.ARRAY_B
+                DataType.UWORD -> DataType.ARRAY_UW
+                DataType.WORD -> DataType.ARRAY_W
+                DataType.FLOAT -> DataType.ARRAY_F
+                else -> {
+                    datatypeErrors.add(SyntaxError("array can only contain bytes/words/floats", position))
+                    DataType.ARRAY_UB
+                }
+            }
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        arraysize?.linkParents(this)
+        value?.linkParents(this)
+        if(structName!=null) {
+            val structStmt = definingScope().lookup(listOf(structName), this)
+            if(structStmt!=null)
+                struct = definingScope().lookup(listOf(structName), this) as StructDecl
+        }
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    val scopedname: String by lazy { makeScopedName(name) }
+
+    override fun toString(): String {
+        return "VarDecl(name=$name, vartype=$type, datatype=$datatype, struct=$structName, value=$value, pos=$position)"
+    }
+
+    fun asDefaultValueDecl(parent: Node?): VarDecl {
+        val constValue = when(declaredDatatype) {
+            DataType.UBYTE -> NumericLiteralValue(DataType.UBYTE, 0,  position)
+            DataType.BYTE -> NumericLiteralValue(DataType.BYTE, 0,  position)
+            DataType.UWORD -> NumericLiteralValue(DataType.UWORD, 0, position)
+            DataType.WORD -> NumericLiteralValue(DataType.WORD, 0, position)
+            DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, 0.0, position)
+            else -> throw FatalAstException("can only set a default value for a numeric type")
+        }
+        val decl = VarDecl(type, declaredDatatype, zeropage, arraysize, name, structName, constValue, isArray, false, position)
+        if(parent!=null)
+            decl.linkParents(parent)
+        return decl
+    }
+
+    fun flattenStructMembers(): MutableList<Statement> {
+        val result = struct!!.statements.withIndex().map {
+            val member = it.value as VarDecl
+            val initvalue = if(value!=null) (value as StructLiteralValue).values[it.index] else null
+            VarDecl(
+                    VarDeclType.VAR,
+                    member.datatype,
+                    ZeropageWish.NOT_IN_ZEROPAGE,
+                    member.arraysize,
+                    mangledStructMemberName(name, member.name),
+                    struct!!.name,
+                    initvalue,
+                    member.isArray,
+                    true,
+                    member.position
+            ) as Statement
+        }.toMutableList()
+        structHasBeenFlattened = true
+        return result
+    }
+}
+
+class ArrayIndex(var index: Expression, override val position: Position) : Node {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        index.linkParents(this)
+    }
+
+    companion object {
+        fun forArray(v: ArrayLiteralValue): ArrayIndex {
+            return ArrayIndex(NumericLiteralValue.optimalNumeric(v.value.size, v.position), v.position)
+        }
+    }
+
+    fun accept(visitor: IAstModifyingVisitor) {
+        index = index.accept(visitor)
+    }
+
+    fun accept(visitor: IAstVisitor) {
+        index.accept(visitor)
+    }
+
+    override fun toString(): String {
+        return("ArrayIndex($index, pos=$position)")
+    }
+
+    fun size() = (index as? NumericLiteralValue)?.number?.toInt()
+}
+
+open class Assignment(var target: AssignTarget, val aug_op : String?, var value: Expression, override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline
+            get() = value !is NumericLiteralValue
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        this.target.linkParents(this)
+        value.linkParents(this)
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    override fun toString(): String {
+        return("Assignment(augop: $aug_op, target: $target, value: $value, pos=$position)")
+    }
+}
+
+// This is a special class so the compiler can see if the assignments are for initializing the vars in the scope,
+// or just a regular assignment. It may optimize the initialization step from this.
+class VariableInitializationAssignment(target: AssignTarget, aug_op: String?, value: Expression, position: Position)
+    : Assignment(target, aug_op, value, position)
+
+data class AssignTarget(val register: Register?,
+                        var identifier: IdentifierReference?,
+                        var arrayindexed: ArrayIndexedExpression?,
+                        val memoryAddress: DirectMemoryWrite?,
+                        override val position: Position) : Node {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        identifier?.linkParents(this)
+        arrayindexed?.linkParents(this)
+        memoryAddress?.linkParents(this)
+    }
+
+    fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    companion object {
+        fun fromExpr(expr: Expression): AssignTarget {
+            return when (expr) {
+                is RegisterExpr -> AssignTarget(expr.register, null, null, null, expr.position)
+                is IdentifierReference -> AssignTarget(null, expr, null, null, expr.position)
+                is ArrayIndexedExpression -> AssignTarget(null, null, expr, null, expr.position)
+                is DirectMemoryRead -> AssignTarget(null, null, null, DirectMemoryWrite(expr.addressExpression, expr.position), expr.position)
+                else -> throw FatalAstException("invalid expression object $expr")
+            }
+        }
+    }
+
+    fun inferType(program: Program, stmt: Statement): InferredTypes.InferredType {
+        if(register!=null)
+            return InferredTypes.knownFor(DataType.UBYTE)
+
+        if(identifier!=null) {
+            val symbol = program.namespace.lookup(identifier!!.nameInSource, stmt) ?: return InferredTypes.unknown()
+            if (symbol is VarDecl) return InferredTypes.knownFor(symbol.datatype)
+        }
+
+        if(arrayindexed!=null) {
+            return arrayindexed!!.inferType(program)
+        }
+
+        if(memoryAddress!=null)
+            return InferredTypes.knownFor(DataType.UBYTE)
+
+        return InferredTypes.unknown()
+    }
+
+    infix fun isSameAs(value: Expression): Boolean {
+        return when {
+            this.memoryAddress!=null -> false
+            this.register!=null -> value is RegisterExpr && value.register==register
+            this.identifier!=null -> value is IdentifierReference && value.nameInSource==identifier!!.nameInSource
+            this.arrayindexed!=null -> value is ArrayIndexedExpression &&
+                    value.identifier.nameInSource==arrayindexed!!.identifier.nameInSource &&
+                    value.arrayspec.size()!=null &&
+                    arrayindexed!!.arrayspec.size()!=null &&
+                    value.arrayspec.size()==arrayindexed!!.arrayspec.size()
+            else -> false
+        }
+    }
+
+    fun isSameAs(other: AssignTarget, program: Program): Boolean {
+        if(this===other)
+            return true
+        if(this.register!=null && other.register!=null)
+            return this.register==other.register
+        if(this.identifier!=null && other.identifier!=null)
+            return this.identifier!!.nameInSource==other.identifier!!.nameInSource
+        if(this.memoryAddress!=null && other.memoryAddress!=null) {
+            val addr1 = this.memoryAddress.addressExpression.constValue(program)
+            val addr2 = other.memoryAddress.addressExpression.constValue(program)
+            return addr1!=null && addr2!=null && addr1==addr2
+        }
+        if(this.arrayindexed!=null && other.arrayindexed!=null) {
+            if(this.arrayindexed!!.identifier.nameInSource == other.arrayindexed!!.identifier.nameInSource) {
+                val x1 = this.arrayindexed!!.arrayspec.index.constValue(program)
+                val x2 = other.arrayindexed!!.arrayspec.index.constValue(program)
+                return x1!=null && x2!=null && x1==x2
+            }
+        }
+        return false
+    }
+
+    fun isNotMemory(namespace: INameScope): Boolean {
+        if(this.register!=null)
+            return true
+        if(this.memoryAddress!=null)
+            return false
+        if(this.arrayindexed!=null) {
+            val targetStmt = this.arrayindexed!!.identifier.targetVarDecl(namespace)
+            if(targetStmt!=null)
+                return targetStmt.type!= VarDeclType.MEMORY
+        }
+        if(this.identifier!=null) {
+            val targetStmt = this.identifier!!.targetVarDecl(namespace)
+            if(targetStmt!=null)
+                return targetStmt.type!= VarDeclType.MEMORY
+        }
+        return false
+    }
+}
+
+class PostIncrDecr(var target: AssignTarget, val operator: String, override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline = false
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        target.linkParents(this)
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    override fun toString(): String {
+        return "PostIncrDecr(op: $operator, target: $target, pos=$position)"
+    }
+}
+
+class Jump(val address: Int?,
+           val identifier: IdentifierReference?,
+           val generatedLabel: String?,             // used in code generation scenarios
+           override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline = false
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        identifier?.linkParents(this)
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    override fun toString(): String {
+        return "Jump(addr: $address, identifier: $identifier, label: $generatedLabel;  pos=$position)"
+    }
+}
+
+class FunctionCallStatement(override var target: IdentifierReference,
+                            override var args: MutableList<Expression>,
+                            val void: Boolean,
+                            override val position: Position) : Statement(), IFunctionCall {
+    override lateinit var parent: Node
+    override val expensiveToInline
+            get() = args.any { it !is NumericLiteralValue }
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        target.linkParents(this)
+        args.forEach { it.linkParents(this) }
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    override fun toString(): String {
+        return "FunctionCallStatement(target=$target, pos=$position)"
+    }
+}
+
+class InlineAssembly(val assembly: String, override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline = true
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+}
+
+class AnonymousScope(override var statements: MutableList<Statement>,
+                     override val position: Position) : INameScope, Statement() {
+    override val name: String
+    override lateinit var parent: Node
+    override val expensiveToInline
+        get() = statements.any { it.expensiveToInline }
+
+    companion object {
+        private var sequenceNumber = 1
+    }
+
+    init {
+        name = "<anon-$sequenceNumber>"     // make sure it's an invalid soruce code identifier so user source code can never produce it
+        sequenceNumber++
+    }
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        statements.forEach { it.linkParents(this) }
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+}
+
+class NopStatement(override val position: Position): Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline = false
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    companion object {
+        fun insteadOf(stmt: Statement): NopStatement {
+            val nop = NopStatement(stmt.position)
+            nop.parent = stmt.parent
+            return nop
+        }
+    }
+}
+
+// the subroutine class covers both the normal user-defined subroutines,
+// and also the predefined/ROM/register-based subroutines.
+// (multiple return types can only occur for the latter type)
+class Subroutine(override val name: String,
+                 val parameters: List<SubroutineParameter>,
+                 val returntypes: List<DataType>,
+                 val asmParameterRegisters: List<RegisterOrStatusflag>,
+                 val asmReturnvaluesRegisters: List<RegisterOrStatusflag>,
+                 val asmClobbers: Set<Register>,
+                 val asmAddress: Int?,
+                 val isAsmSubroutine: Boolean,
+                 override var statements: MutableList<Statement>,
+                 override val position: Position) : Statement(), INameScope {
+
+    var keepAlways: Boolean = false
+    override val expensiveToInline
+            get() = statements.any { it.expensiveToInline }
+
+    override lateinit var parent: Node
+    val calledBy = mutableListOf<Node>()
+    val calls = mutableSetOf<Subroutine>()
+
+    val scopedname: String by lazy { makeScopedName(name) }
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        parameters.forEach { it.linkParents(this) }
+        statements.forEach { it.linkParents(this) }
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    override fun toString(): String {
+        return "Subroutine(name=$name, parameters=$parameters, returntypes=$returntypes, ${statements.size} statements, address=$asmAddress)"
+    }
+
+    fun amountOfRtsInAsm(): Int = statements
+            .asSequence()
+            .filter { it is InlineAssembly }
+            .map { (it as InlineAssembly).assembly }
+            .count { " rti" in it || "\trti" in it || " rts" in it || "\trts" in it || " jmp" in it || "\tjmp" in it }
+}
+
+open class SubroutineParameter(val name: String,
+                               val type: DataType,
+                               override val position: Position) : Node {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+    }
+}
+
+class IfStatement(var condition: Expression,
+                  var truepart: AnonymousScope,
+                  var elsepart: AnonymousScope,
+                  override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline: Boolean
+        get() = truepart.expensiveToInline || elsepart.expensiveToInline
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        condition.linkParents(this)
+        truepart.linkParents(this)
+        elsepart.linkParents(this)
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+}
+
+class BranchStatement(var condition: BranchCondition,
+                      var truepart: AnonymousScope,
+                      var elsepart: AnonymousScope,
+                      override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline: Boolean
+        get() = truepart.expensiveToInline || elsepart.expensiveToInline
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        truepart.linkParents(this)
+        elsepart.linkParents(this)
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+}
+
+class ForLoop(val loopRegister: Register?,
+              var loopVar: IdentifierReference?,
+              var iterable: Expression,
+              var body: AnonymousScope,
+              override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline = true
+
+    override fun linkParents(parent: Node) {
+        this.parent=parent
+        loopVar?.linkParents(this)
+        iterable.linkParents(this)
+        body.linkParents(this)
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+
+    override fun toString(): String {
+        return "ForLoop(loopVar: $loopVar, loopReg: $loopRegister, iterable: $iterable, pos=$position)"
+    }
+}
+
+class WhileLoop(var condition: Expression,
+                var body: AnonymousScope,
+                override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline = true
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        condition.linkParents(this)
+        body.linkParents(this)
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+}
+
+class RepeatLoop(var body: AnonymousScope,
+                 var untilCondition: Expression,
+                 override val position: Position) : Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline = true
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        untilCondition.linkParents(this)
+        body.linkParents(this)
+    }
+
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+}
+
+class WhenStatement(var condition: Expression,
+                    var choices: MutableList<WhenChoice>,
+                    override val position: Position): Statement() {
+    override lateinit var parent: Node
+    override val expensiveToInline: Boolean = true
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        condition.linkParents(this)
+        choices.forEach { it.linkParents(this) }
+    }
+
+    fun choiceValues(program: Program): List<Pair<List<Int>?, WhenChoice>> {
+        // only gives sensible results when the choices are all valid (constant integers)
+        val result = mutableListOf<Pair<List<Int>?, WhenChoice>>()
+        for(choice in choices) {
+            if(choice.values==null)
+                result.add(null to choice)
+            else {
+                val values = choice.values!!.map { it.constValue(program)?.number?.toInt() }
+                if(values.contains(null))
+                    result.add(null to choice)
+                else
+                    result.add(values.filterNotNull() to choice)
+            }
+        }
+        return result
+    }
+
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+}
+
+class WhenChoice(var values: List<Expression>?,           // if null,  this is the 'else' part
+                 var statements: AnonymousScope,
+                 override val position: Position) : Node {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        values?.forEach { it.linkParents(this) }
+        statements.linkParents(this)
+        this.parent = parent
+    }
+
+    override fun toString(): String {
+        return "Choice($values at $position)"
+    }
+
+    fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+}
+
+
+class StructDecl(override val name: String,
+                 override var statements: MutableList<Statement>,      // actually, only vardecls here
+                 override val position: Position): Statement(), INameScope {
+
+    override lateinit var parent: Node
+    override val expensiveToInline: Boolean = true
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        this.statements.forEach { it.linkParents(this) }
+    }
+
+    val numberOfElements: Int
+        get() = this.statements.size
+
+    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+
+    fun nameOfFirstMember() = (statements.first() as VarDecl).name
+}
+
+class DirectMemoryWrite(var addressExpression: Expression, override val position: Position) : Node {
+    override lateinit var parent: Node
+
+    override fun linkParents(parent: Node) {
+        this.parent = parent
+        this.addressExpression.linkParents(this)
+    }
+
+    override fun toString(): String {
+        return "DirectMemoryWrite($addressExpression)"
+    }
+
+    fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+}

compiler/src/prog8/astvm/AstVm.kt

@@ -1,563 +0,0 @@
-package prog8.astvm
-
-import prog8.ast.*
-import prog8.compiler.RuntimeValue
-import prog8.compiler.RuntimeValueRange
-import prog8.compiler.target.c64.Petscii
-import java.awt.EventQueue
-
-
-class VmExecutionException(msg: String?) : Exception(msg)
-
-class VmTerminationException(msg: String?) : Exception(msg)
-
-class VmBreakpointException : Exception("breakpoint")
-
-
-class StatusFlags {
-    var carry: Boolean = false
-    var zero: Boolean = true
-    var negative: Boolean = false
-    var irqd: Boolean = false
-
-    private fun setFlags(value: LiteralValue?) {
-        if (value != null) {
-            when (value.type) {
-                DataType.UBYTE -> {
-                    val v = value.bytevalue!!.toInt()
-                    negative = v > 127
-                    zero = v == 0
-                }
-                DataType.BYTE -> {
-                    val v = value.bytevalue!!.toInt()
-                    negative = v < 0
-                    zero = v == 0
-                }
-                DataType.UWORD -> {
-                    val v = value.wordvalue!!
-                    negative = v > 32767
-                    zero = v == 0
-                }
-                DataType.WORD -> {
-                    val v = value.wordvalue!!
-                    negative = v < 0
-                    zero = v == 0
-                }
-                DataType.FLOAT -> {
-                    val flt = value.floatvalue!!
-                    negative = flt < 0.0
-                    zero = flt == 0.0
-                }
-                else -> {
-                    // no flags for non-numeric type
-                }
-            }
-        }
-    }
-}
-
-
-class RuntimeVariables {
-    fun define(scope: INameScope, name: String, initialValue: RuntimeValue) {
-        val where = vars.getValue(scope)
-        where[name] = initialValue
-        vars[scope] = where
-    }
-
-    fun defineMemory(scope: INameScope, name: String, address: Int) {
-        val where = memvars.getValue(scope)
-        where[name] = address
-        memvars[scope] = where
-    }
-
-    fun set(scope: INameScope, name: String, value: RuntimeValue) {
-        val where = vars.getValue(scope)
-        val existing = where[name]
-        if(existing==null) {
-            if(memvars.getValue(scope)[name]!=null)
-                throw NoSuchElementException("this is a memory mapped var, not a normal var: ${scope.name}.$name")
-            throw NoSuchElementException("no such runtime variable: ${scope.name}.$name")
-        }
-        if(existing.type!=value.type)
-            throw VmExecutionException("new value is of different datatype ${value.type} expected ${existing.type} for $name")
-        where[name] = value
-        vars[scope] = where
-    }
-
-    fun get(scope: INameScope, name: String): RuntimeValue {
-        val where = vars.getValue(scope)
-        val value = where[name] ?: throw NoSuchElementException("no such runtime variable: ${scope.name}.$name")
-        return value
-    }
-
-    fun getMemoryAddress(scope: INameScope, name: String): Int {
-        val where = memvars.getValue(scope)
-        val address = where[name] ?: throw NoSuchElementException("no such runtime memory-variable: ${scope.name}.$name")
-        return address
-    }
-
-    fun swap(a1: VarDecl, a2: VarDecl) = swap(a1.definingScope(), a1.name, a2.definingScope(), a2.name)
-
-    fun swap(scope1: INameScope, name1: String, scope2: INameScope, name2: String) {
-        val v1 = get(scope1, name1)
-        val v2 = get(scope2, name2)
-        set(scope1, name1, v2)
-        set(scope2, name2, v1)
-    }
-
-    private val vars = mutableMapOf<INameScope, MutableMap<String, RuntimeValue>>().withDefault { mutableMapOf() }
-    private val memvars = mutableMapOf<INameScope, MutableMap<String, Int>>().withDefault { mutableMapOf() }
-}
-
-
-class AstVm(val program: Program) {
-    val mem = Memory()
-    val statusflags = StatusFlags()
-
-    private var dialog = ScreenDialog()
-    var instructionCounter = 0
-
-    init {
-        dialog.requestFocusInWindow()
-
-        EventQueue.invokeLater {
-            dialog.pack()
-            dialog.isVisible = true
-            dialog.start()
-        }
-    }
-
-    fun run() {
-        try {
-            val init = VariablesCreator(runtimeVariables, program.heap)
-            init.process(program)
-
-            // initialize all global variables
-            for (m in program.modules) {
-                for (b in m.statements.filterIsInstance<Block>()) {
-                    for (s in b.statements.filterIsInstance<Subroutine>()) {
-                        if (s.name == initvarsSubName) {
-                            try {
-                                executeSubroutine(s, emptyList(), null)
-                            } catch (x: LoopControlReturn) {
-                                // regular return
-                            }
-                        }
-                    }
-                }
-            }
-
-            var entrypoint: Subroutine? = program.entrypoint() ?: throw VmTerminationException("no valid entrypoint found")
-            var startlabel: Label? = null
-
-            while(entrypoint!=null) {
-                try {
-                    executeSubroutine(entrypoint, emptyList(), startlabel)
-                    entrypoint = null
-                } catch (rx: LoopControlReturn) {
-                    // regular return
-                } catch (jx: LoopControlJump) {
-                    if (jx.address != null)
-                        throw VmTerminationException("doesn't support jumping to machine address ${jx.address}")
-                    when {
-                        jx.generatedLabel != null -> {
-                            val label = entrypoint.getLabelOrVariable(jx.generatedLabel) as Label
-                            TODO("generatedlabel $label")
-                        }
-                        jx.identifier != null -> {
-                            when (val jumptarget = entrypoint.lookup(jx.identifier.nameInSource, jx.identifier.parent)) {
-                                is Label -> {
-                                    startlabel = jumptarget
-                                    entrypoint = jumptarget.definingSubroutine()
-                                }
-                                is Subroutine -> entrypoint = jumptarget
-                                else -> throw VmTerminationException("weird jump target $jumptarget")
-                            }
-                        }
-                        else -> throw VmTerminationException("unspecified jump target")
-                    }
-                }
-            }
-            println("PROGRAM EXITED!")
-            dialog.title = "PROGRAM EXITED"
-        } catch (tx: VmTerminationException) {
-            println("Execution halted: ${tx.message}")
-        } catch (xx: VmExecutionException) {
-            println("Execution error: ${xx.message}")
-            throw xx
-        }
-    }
-
-    private val runtimeVariables = RuntimeVariables()
-    private val functions = BuiltinFunctions()
-    private val evalCtx = EvalContext(program, mem, statusflags, runtimeVariables, functions, ::executeSubroutine)
-
-    class LoopControlBreak : Exception()
-    class LoopControlContinue : Exception()
-    class LoopControlReturn(val returnvalues: List<RuntimeValue>) : Exception()
-    class LoopControlJump(val identifier: IdentifierReference?, val address: Int?, val generatedLabel: String?) : Exception()
-
-
-    internal fun executeSubroutine(sub: Subroutine, arguments: List<RuntimeValue>, startlabel: Label?=null): List<RuntimeValue> {
-        assert(!sub.isAsmSubroutine)
-        if (sub.statements.isEmpty())
-            throw VmTerminationException("scope contains no statements: $sub")
-        if (arguments.size != sub.parameters.size)
-            throw VmTerminationException("number of args doesn't match number of required parameters")
-
-        for (arg in sub.parameters.zip(arguments)) {
-            val idref = IdentifierReference(listOf(arg.first.name), sub.position)
-            performAssignment(AssignTarget(null, idref, null, null, idref.position),
-                    arg.second, sub.statements.first(), evalCtx)
-        }
-
-        val statements = sub.statements.iterator()
-        if(startlabel!=null) {
-            do {
-                val stmt = statements.next()
-            } while(stmt!==startlabel)
-        }
-
-        try {
-            while(statements.hasNext()) {
-                val s = statements.next()
-                try {
-                    executeStatement(sub, s)
-                }
-                catch (b: VmBreakpointException) {
-                    print("BREAKPOINT HIT at ${s.position} - Press enter to continue:")
-                    readLine()
-                }
-            }
-        } catch (r: LoopControlReturn) {
-            return r.returnvalues
-        }
-        throw VmTerminationException("instruction pointer overflow, is a return missing? $sub")
-    }
-
-    internal fun executeAnonymousScope(scope: INameScope) {
-        for (s in scope.statements) {
-            executeStatement(scope, s)
-        }
-    }
-
-
-    private fun executeStatement(sub: INameScope, stmt: IStatement) {
-        instructionCounter++
-        if (instructionCounter % 100 == 0)
-            Thread.sleep(1)
-        when (stmt) {
-            is NopStatement, is Label, is Subroutine -> {
-                // do nothing, skip this instruction
-            }
-            is Directive -> {
-                if (stmt.directive == "%breakpoint")
-                    throw VmBreakpointException()
-                else if (stmt.directive == "%asm")
-                    throw VmExecutionException("can't execute assembly code")
-            }
-            is VarDecl -> {
-                // should have been defined already when the program started
-            }
-            is FunctionCallStatement -> {
-                val target = stmt.target.targetStatement(program.namespace)
-                when (target) {
-                    is Subroutine -> {
-                        val args = evaluate(stmt.arglist)
-                        if (target.isAsmSubroutine) {
-                            performSyscall(target, args)
-                        } else {
-                            executeSubroutine(target, args, null)
-                            // any return value(s) are discarded
-                        }
-                    }
-                    is BuiltinFunctionStatementPlaceholder -> {
-                        if(target.name=="swap") {
-                            // swap cannot be implemented as a function, so inline it here
-                            executeSwap(stmt)
-                        } else {
-                            val args = evaluate(stmt.arglist)
-                            functions.performBuiltinFunction(target.name, args, statusflags)
-                        }
-                    }
-                    else -> {
-                        TODO("weird call $target")
-                    }
-                }
-            }
-            is Return -> throw LoopControlReturn(stmt.values.map { evaluate(it, evalCtx) })
-            is Continue -> throw LoopControlContinue()
-            is Break -> throw LoopControlBreak()
-            is Assignment -> {
-                if (stmt.aug_op != null)
-                    throw VmExecutionException("augmented assignment should have been converted into regular one $stmt")
-                val target = stmt.singleTarget
-                if (target != null) {
-                    val value = evaluate(stmt.value, evalCtx)
-                    performAssignment(target, value, stmt, evalCtx)
-                } else TODO("assign multitarget $stmt")
-            }
-            is PostIncrDecr -> {
-                when {
-                    stmt.target.identifier != null -> {
-                        val ident = stmt.definingScope().lookup(stmt.target.identifier!!.nameInSource, stmt) as VarDecl
-                        val identScope = ident.definingScope()
-                        var value = runtimeVariables.get(identScope, ident.name)
-                        value = when {
-                            stmt.operator == "++" -> value.add(RuntimeValue(value.type, 1))
-                            stmt.operator == "--" -> value.sub(RuntimeValue(value.type, 1))
-                            else -> throw VmExecutionException("strange postincdec operator $stmt")
-                        }
-                        runtimeVariables.set(identScope, ident.name, value)
-                    }
-                    stmt.target.memoryAddress != null -> {
-                        TODO("postincrdecr memory $stmt")
-                    }
-                    stmt.target.arrayindexed != null -> {
-                        TODO("postincrdecr array $stmt")
-                    }
-                }
-            }
-            is Jump -> throw LoopControlJump(stmt.identifier, stmt.address, stmt.generatedLabel)
-            is InlineAssembly -> {
-                if (sub is Subroutine) {
-                    val args = sub.parameters.map { runtimeVariables.get(sub, it.name) }
-                    performSyscall(sub, args)
-                    throw LoopControlReturn(emptyList())
-                }
-                throw VmExecutionException("can't execute inline assembly in $sub")
-            }
-            is AnonymousScope -> executeAnonymousScope(stmt)
-            is IfStatement -> {
-                val condition = evaluate(stmt.condition, evalCtx)
-                if (condition.asBoolean)
-                    executeAnonymousScope(stmt.truepart)
-                else
-                    executeAnonymousScope(stmt.elsepart)
-            }
-            is BranchStatement -> {
-                when(stmt.condition) {
-                    BranchCondition.CS -> if(statusflags.carry) executeAnonymousScope(stmt.truepart) else executeAnonymousScope(stmt.elsepart)
-                    BranchCondition.CC -> if(!statusflags.carry) executeAnonymousScope(stmt.truepart) else executeAnonymousScope(stmt.elsepart)
-                    BranchCondition.EQ, BranchCondition.Z -> if(statusflags.zero) executeAnonymousScope(stmt.truepart) else executeAnonymousScope(stmt.elsepart)
-                    BranchCondition.NE, BranchCondition.NZ -> if(statusflags.zero) executeAnonymousScope(stmt.truepart) else executeAnonymousScope(stmt.elsepart)
-                    BranchCondition.MI, BranchCondition.NEG -> if(statusflags.negative) executeAnonymousScope(stmt.truepart) else executeAnonymousScope(stmt.elsepart)
-                    BranchCondition.PL, BranchCondition.POS -> if(statusflags.negative) executeAnonymousScope(stmt.truepart) else executeAnonymousScope(stmt.elsepart)
-                    BranchCondition.VS, BranchCondition.VC -> TODO("overflow status")
-                }
-            }
-            is ForLoop -> {
-                val iterable = evaluate(stmt.iterable, evalCtx)
-                if (iterable.type !in IterableDatatypes && iterable !is RuntimeValueRange)
-                    throw VmExecutionException("can only iterate over an iterable value:  $stmt")
-                val loopvarDt: DataType
-                val loopvar: IdentifierReference
-                if (stmt.loopRegister != null) {
-                    loopvarDt = DataType.UBYTE
-                    loopvar = IdentifierReference(listOf(stmt.loopRegister.name), stmt.position)
-                } else {
-                    loopvarDt = stmt.loopVar!!.inferType(program)!!
-                    loopvar = stmt.loopVar
-                }
-                val iterator = iterable.iterator()
-                for (loopvalue in iterator) {
-                    try {
-                        oneForCycle(stmt, loopvarDt, loopvalue, loopvar)
-                    } catch (b: LoopControlBreak) {
-                        break
-                    } catch (c: LoopControlContinue) {
-                        continue
-                    }
-                }
-            }
-            is WhileLoop -> {
-                var condition = evaluate(stmt.condition, evalCtx)
-                while (condition.asBoolean) {
-                    try {
-                        executeAnonymousScope(stmt.body)
-                        condition = evaluate(stmt.condition, evalCtx)
-                    } catch (b: LoopControlBreak) {
-                        break
-                    } catch (c: LoopControlContinue) {
-                        continue
-                    }
-                }
-            }
-            is RepeatLoop -> {
-                do {
-                    val condition = evaluate(stmt.untilCondition, evalCtx)
-                    try {
-                        executeAnonymousScope(stmt.body)
-                    } catch (b: LoopControlBreak) {
-                        break
-                    } catch (c: LoopControlContinue) {
-                        continue
-                    }
-                } while (!condition.asBoolean)
-            }
-            else -> {
-                TODO("implement $stmt")
-            }
-        }
-    }
-
-    private fun executeSwap(swap: FunctionCallStatement) {
-        val v1 = swap.arglist[0]
-        val v2 = swap.arglist[1]
-        val value1 = evaluate(v1, evalCtx)
-        val value2 = evaluate(v2, evalCtx)
-        val target1 = AssignTarget.fromExpr(v1)
-        val target2 = AssignTarget.fromExpr(v2)
-        performAssignment(target1, value2, swap, evalCtx)
-        performAssignment(target2, value1, swap, evalCtx)
-    }
-
-    fun performAssignment(target: AssignTarget, value: RuntimeValue, contextStmt: IStatement, evalCtx: EvalContext) {
-        when {
-            target.identifier != null -> {
-                val decl = contextStmt.definingScope().lookup(target.identifier.nameInSource, contextStmt) as? VarDecl
-                        ?: throw VmExecutionException("can't find assignment target ${target.identifier}")
-                if (decl.type == VarDeclType.MEMORY) {
-                    val address = runtimeVariables.getMemoryAddress(decl.definingScope(), decl.name)
-                    when (decl.datatype) {
-                        DataType.UBYTE -> mem.setUByte(address, value.byteval!!)
-                        DataType.BYTE -> mem.setSByte(address, value.byteval!!)
-                        DataType.UWORD -> mem.setUWord(address, value.wordval!!)
-                        DataType.WORD -> mem.setSWord(address, value.wordval!!)
-                        DataType.FLOAT -> mem.setFloat(address, value.floatval!!)
-                        DataType.STR -> mem.setString(address, value.str!!)
-                        DataType.STR_S -> mem.setScreencodeString(address, value.str!!)
-                        else -> TODO("set memvar $decl")
-                    }
-                } else
-                    runtimeVariables.set(decl.definingScope(), decl.name, value)
-            }
-            target.memoryAddress != null -> {
-                val address = evaluate(target.memoryAddress!!.addressExpression, evalCtx).wordval!!
-                evalCtx.mem.setUByte(address, value.byteval!!)
-            }
-            target.arrayindexed != null -> {
-                val array = evaluate(target.arrayindexed.identifier, evalCtx)
-                val index = evaluate(target.arrayindexed.arrayspec.index, evalCtx)
-                when (array.type) {
-                    DataType.ARRAY_UB -> {
-                        if (value.type != DataType.UBYTE)
-                            throw VmExecutionException("new value is of different datatype ${value.type} for $array")
-                    }
-                    DataType.ARRAY_B -> {
-                        if (value.type != DataType.BYTE)
-                            throw VmExecutionException("new value is of different datatype ${value.type} for $array")
-                    }
-                    DataType.ARRAY_UW -> {
-                        if (value.type != DataType.UWORD)
-                            throw VmExecutionException("new value is of different datatype ${value.type} for $array")
-                    }
-                    DataType.ARRAY_W -> {
-                        if (value.type != DataType.WORD)
-                            throw VmExecutionException("new value is of different datatype ${value.type} for $array")
-                    }
-                    DataType.ARRAY_F -> {
-                        if (value.type != DataType.FLOAT)
-                            throw VmExecutionException("new value is of different datatype ${value.type} for $array")
-                    }
-                    DataType.STR, DataType.STR_S -> {
-                        if (value.type !in ByteDatatypes)
-                            throw VmExecutionException("new value is of different datatype ${value.type} for $array")
-                    }
-                    else -> throw VmExecutionException("strange array type ${array.type}")
-                }
-                if (array.type in ArrayDatatypes)
-                    array.array!![index.integerValue()] = value.numericValue()
-                else if (array.type in StringDatatypes) {
-                    val indexInt = index.integerValue()
-                    val newchr = Petscii.decodePetscii(listOf(value.numericValue().toShort()), true)
-                    val newstr = array.str!!.replaceRange(indexInt, indexInt + 1, newchr)
-                    val ident = contextStmt.definingScope().lookup(target.arrayindexed.identifier.nameInSource, contextStmt) as? VarDecl
-                            ?: throw VmExecutionException("can't find assignment target ${target.identifier}")
-                    val identScope = ident.definingScope()
-                    program.heap.update(array.heapId!!, newstr)
-                    runtimeVariables.set(identScope, ident.name, RuntimeValue(array.type, str = newstr, heapId = array.heapId))
-                }
-            }
-            target.register != null -> {
-                runtimeVariables.set(program.namespace, target.register.name, value)
-            }
-            else -> TODO("assign $target")
-        }
-    }
-
-    private fun oneForCycle(stmt: ForLoop, loopvarDt: DataType, loopValue: Number, loopVar: IdentifierReference) {
-        // assign the new loop value to the loopvar, and run the code
-        performAssignment(AssignTarget(null, loopVar, null, null, loopVar.position),
-                RuntimeValue(loopvarDt, loopValue), stmt.body.statements.first(), evalCtx)
-        executeAnonymousScope(stmt.body)
-    }
-
-    private fun evaluate(args: List<IExpression>) = args.map { evaluate(it, evalCtx) }
-
-    private fun performSyscall(sub: Subroutine, args: List<RuntimeValue>) {
-        assert(sub.isAsmSubroutine)
-        when (sub.scopedname) {
-            "c64scr.print" -> {
-                // if the argument is an UWORD, consider it to be the "address" of the string (=heapId)
-                if (args[0].wordval != null) {
-                    val str = program.heap.get(args[0].wordval!!).str!!
-                    dialog.canvas.printText(str, 1, true)
-                } else
-                    dialog.canvas.printText(args[0].str!!, 1, true)
-            }
-            "c64scr.print_ub" -> {
-                dialog.canvas.printText(args[0].byteval!!.toString(), 1, true)
-            }
-            "c64scr.print_b" -> {
-                dialog.canvas.printText(args[0].byteval!!.toString(), 1, true)
-            }
-            "c64scr.print_uw" -> {
-                dialog.canvas.printText(args[0].wordval!!.toString(), 1, true)
-            }
-            "c64scr.print_w" -> {
-                dialog.canvas.printText(args[0].wordval!!.toString(), 1, true)
-            }
-            "c64scr.print_ubhex" -> {
-                val prefix = if (args[0].asBoolean) "$" else ""
-                val number = args[1].byteval!!
-                dialog.canvas.printText("$prefix${number.toString(16).padStart(2, '0')}", 1, true)
-            }
-            "c64scr.print_uwhex" -> {
-                val prefix = if (args[0].asBoolean) "$" else ""
-                val number = args[1].wordval!!
-                dialog.canvas.printText("$prefix${number.toString(16).padStart(4, '0')}", 1, true)
-            }
-            "c64scr.print_uwbin" -> {
-                val prefix = if (args[0].asBoolean) "%" else ""
-                val number = args[1].wordval!!
-                dialog.canvas.printText("$prefix${number.toString(2).padStart(16, '0')}", 1, true)
-            }
-            "c64scr.print_ubbin" -> {
-                val prefix = if (args[0].asBoolean) "%" else ""
-                val number = args[1].byteval!!
-                dialog.canvas.printText("$prefix${number.toString(2).padStart(8, '0')}", 1, true)
-            }
-            "c64scr.clear_screenchars" -> {
-                dialog.canvas.clearScreen(6)
-            }
-            "c64scr.clear_screen" -> {
-                dialog.canvas.clearScreen(args[0].integerValue().toShort())
-            }
-            "c64scr.setcc" -> {
-                dialog.canvas.setChar(args[0].integerValue(), args[1].integerValue(), args[2].integerValue().toShort(), args[3].integerValue().toShort())
-            }
-            "c64scr.plot" -> {
-                dialog.canvas.setCursorPos(args[0].integerValue(), args[1].integerValue())
-            }
-            "c64.CHROUT" -> {
-                dialog.canvas.printChar(args[0].byteval!!)
-            }
-            "c64flt.print_f" -> {
-                dialog.canvas.printText(args[0].floatval.toString(), 1, true)
-            }
-            else -> TODO("syscall  ${sub.scopedname} $sub")
-        }
-    }
-}
-

compiler/src/prog8/astvm/BuiltinFunctions.kt

@@ -1,204 +0,0 @@
-package prog8.astvm
-
-import prog8.ast.DataType
-import prog8.compiler.RuntimeValue
-import java.lang.Math.toDegrees
-import java.lang.Math.toRadians
-import java.util.*
-import kotlin.math.*
-import kotlin.random.Random
-
-
-class BuiltinFunctions {
-
-    private val rnd = Random(0)
-    private val statusFlagsSave = Stack<StatusFlags>()
-
-
-    fun performBuiltinFunction(name: String, args: List<RuntimeValue>, statusflags: StatusFlags): RuntimeValue? {
-        return when (name) {
-            "rnd" -> RuntimeValue(DataType.UBYTE, rnd.nextInt() and 255)
-            "rndw" -> RuntimeValue(DataType.UWORD, rnd.nextInt() and 65535)
-            "rndf" -> RuntimeValue(DataType.FLOAT, rnd.nextDouble())
-            "lsb" -> RuntimeValue(DataType.UBYTE, args[0].integerValue() and 255)
-            "msb" -> RuntimeValue(DataType.UBYTE, (args[0].integerValue() ushr 8) and 255)
-            "sin" -> RuntimeValue(DataType.FLOAT, sin(args[0].numericValue().toDouble()))
-            "sin8" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.BYTE, (127.0 * sin(rad)).toShort())
-            }
-            "sin8u" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.UBYTE, (128.0 + 127.5 * sin(rad)).toShort())
-            }
-            "sin16" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.BYTE, (32767.0 * sin(rad)).toShort())
-            }
-            "sin16u" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.UBYTE, (32768.0 + 32767.5 * sin(rad)).toShort())
-            }
-            "cos" -> RuntimeValue(DataType.FLOAT, cos(args[0].numericValue().toDouble()))
-            "cos8" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.BYTE, (127.0 * cos(rad)).toShort())
-            }
-            "cos8u" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.UBYTE, (128.0 + 127.5 * cos(rad)).toShort())
-            }
-            "cos16" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.BYTE, (32767.0 * cos(rad)).toShort())
-            }
-            "cos16u" -> {
-                val rad = args[0].numericValue().toDouble() / 256.0 * 2.0 * PI
-                RuntimeValue(DataType.UBYTE, (32768.0 + 32767.5 * cos(rad)).toShort())
-            }
-            "tan" -> RuntimeValue(DataType.FLOAT, tan(args[0].numericValue().toDouble()))
-            "atan" -> RuntimeValue(DataType.FLOAT, atan(args[0].numericValue().toDouble()))
-            "ln" -> RuntimeValue(DataType.FLOAT, ln(args[0].numericValue().toDouble()))
-            "log2" -> RuntimeValue(DataType.FLOAT, log2(args[0].numericValue().toDouble()))
-            "sqrt" -> RuntimeValue(DataType.FLOAT, sqrt(args[0].numericValue().toDouble()))
-            "sqrt16" -> RuntimeValue(DataType.UBYTE, sqrt(args[0].wordval!!.toDouble()).toInt())
-            "rad" -> RuntimeValue(DataType.FLOAT, toRadians(args[0].numericValue().toDouble()))
-            "deg" -> RuntimeValue(DataType.FLOAT, toDegrees(args[0].numericValue().toDouble()))
-            "round" -> RuntimeValue(DataType.FLOAT, round(args[0].numericValue().toDouble()))
-            "floor" -> RuntimeValue(DataType.FLOAT, floor(args[0].numericValue().toDouble()))
-            "ceil" -> RuntimeValue(DataType.FLOAT, ceil(args[0].numericValue().toDouble()))
-            "rol" -> {
-                val (result, newCarry) = args[0].rol(statusflags.carry)
-                statusflags.carry = newCarry
-                return result
-            }
-            "rol2" -> args[0].rol2()
-            "ror" -> {
-                val (result, newCarry) = args[0].ror(statusflags.carry)
-                statusflags.carry = newCarry
-                return result
-            }
-            "ror2" -> args[0].ror2()
-            "lsl" -> args[0].shl()
-            "lsr" -> args[0].shr()
-            "abs" -> {
-                when (args[0].type) {
-                    DataType.UBYTE -> args[0]
-                    DataType.BYTE -> RuntimeValue(DataType.UBYTE, abs(args[0].numericValue().toDouble()))
-                    DataType.UWORD -> args[0]
-                    DataType.WORD -> RuntimeValue(DataType.UWORD, abs(args[0].numericValue().toDouble()))
-                    DataType.FLOAT -> RuntimeValue(DataType.FLOAT, abs(args[0].numericValue().toDouble()))
-                    else -> TODO("strange abs type")
-                }
-            }
-            "max" -> {
-                val numbers = args.map { it.numericValue().toDouble() }
-                RuntimeValue(args[0].type, numbers.max())
-            }
-            "min" -> {
-                val numbers = args.map { it.numericValue().toDouble() }
-                RuntimeValue(args[0].type, numbers.min())
-            }
-            "avg" -> {
-                val numbers = args.map { it.numericValue().toDouble() }
-                RuntimeValue(DataType.FLOAT, numbers.average())
-            }
-            "sum" -> {
-                val sum = args.map { it.numericValue().toDouble() }.sum()
-                when (args[0].type) {
-                    DataType.UBYTE -> RuntimeValue(DataType.UWORD, sum)
-                    DataType.BYTE -> RuntimeValue(DataType.WORD, sum)
-                    DataType.UWORD -> RuntimeValue(DataType.UWORD, sum)
-                    DataType.WORD -> RuntimeValue(DataType.WORD, sum)
-                    DataType.FLOAT -> RuntimeValue(DataType.FLOAT, sum)
-                    else -> TODO("weird sum type")
-                }
-            }
-            "any" -> {
-                val numbers = args.map { it.numericValue().toDouble() }
-                RuntimeValue(DataType.UBYTE, if (numbers.any { it != 0.0 }) 1 else 0)
-            }
-            "all" -> {
-                val numbers = args.map { it.numericValue().toDouble() }
-                RuntimeValue(DataType.UBYTE, if (numbers.all { it != 0.0 }) 1 else 0)
-            }
-            "swap" ->
-                throw VmExecutionException("swap() cannot be implemented as a function")
-            "strlen" -> {
-                val zeroIndex = args[0].str!!.indexOf(0.toChar())
-                if (zeroIndex >= 0)
-                    RuntimeValue(DataType.UBYTE, zeroIndex)
-                else
-                    RuntimeValue(DataType.UBYTE, args[0].str!!.length)
-            }
-            "memset" -> {
-                val target = args[0].array!!
-                val amount = args[1].integerValue()
-                val value = args[2].integerValue()
-                for (i in 0 until amount) {
-                    target[i] = value
-                }
-                null
-            }
-            "memsetw" -> {
-                val target = args[0].array!!
-                val amount = args[1].integerValue()
-                val value = args[2].integerValue()
-                for (i in 0 until amount step 2) {
-                    target[i * 2] = value and 255
-                    target[i * 2 + 1] = value ushr 8
-                }
-                null
-            }
-            "memcopy" -> {
-                val source = args[0].array!!
-                val dest = args[1].array!!
-                val amount = args[2].integerValue()
-                for(i in 0 until amount) {
-                    dest[i] = source[i]
-                }
-                null
-            }
-            "mkword" -> {
-                val result = (args[0].integerValue() shl 8) or args[1].integerValue()
-                RuntimeValue(DataType.UWORD, result)
-            }
-            "set_carry" -> {
-                statusflags.carry=true
-                null
-            }
-            "clear_carry" -> {
-                statusflags.carry=false
-                null
-            }
-            "set_irqd" -> {
-                statusflags.irqd=true
-                null
-            }
-            "clear_irqd" -> {
-                statusflags.irqd=false
-                null
-            }
-            "read_flags" -> {
-                val carry = if(statusflags.carry) 1 else 0
-                val zero = if(statusflags.zero) 2 else 0
-                val irqd = if(statusflags.irqd) 4 else 0
-                val negative = if(statusflags.negative) 128 else 0
-                RuntimeValue(DataType.UBYTE, carry or zero or irqd or negative)
-            }
-            "rsave" -> {
-                statusFlagsSave.push(statusflags)
-                null
-            }
-            "rrestore" -> {
-                val flags = statusFlagsSave.pop()
-                statusflags.carry = flags.carry
-                statusflags.negative = flags.negative
-                statusflags.zero = flags.zero
-                statusflags.irqd = flags.irqd
-                null
-            }
-            else -> TODO("builtin function $name")
-        }
-    }
-}

compiler/src/prog8/astvm/CallStack.kt

@@ -1,18 +0,0 @@
-package prog8.astvm
-
-import prog8.ast.INameScope
-import java.util.*
-
-class CallStack {
-
-    private val stack = Stack<Pair<INameScope, Int>>()
-
-    fun pop(): Pair<INameScope, Int> {
-        return stack.pop()
-    }
-
-    fun push(scope: INameScope, index: Int) {
-        stack.push(Pair(scope, index))
-    }
-
-}

compiler/src/prog8/astvm/Expressions.kt

@@ -1,154 +0,0 @@
-package prog8.astvm
-
-import prog8.ast.*
-import prog8.compiler.RuntimeValue
-import prog8.compiler.RuntimeValueRange
-import kotlin.math.abs
-
-class EvalContext(val program: Program, val mem: Memory, val statusflags: StatusFlags,
-                  val runtimeVars: RuntimeVariables, val functions: BuiltinFunctions,
-                  val executeSubroutine: (sub: Subroutine, args: List<RuntimeValue>, startlabel: Label?) -> List<RuntimeValue>)
-
-fun evaluate(expr: IExpression, ctx: EvalContext): RuntimeValue {
-    val constval = expr.constValue(ctx.program)
-    if(constval!=null)
-        return RuntimeValue.from(constval, ctx.program.heap)
-
-    when(expr) {
-        is LiteralValue -> {
-            return RuntimeValue.from(expr, ctx.program.heap)
-        }
-        is PrefixExpression -> {
-            return when(expr.operator) {
-                "-" -> evaluate(expr.expression, ctx).neg()
-                "~" -> evaluate(expr.expression, ctx).inv()
-                "not" -> evaluate(expr.expression, ctx).not()
-                // unary '+' should have been optimized away
-                else -> TODO("prefixexpr ${expr.operator}")
-            }
-        }
-        is BinaryExpression -> {
-            val left = evaluate(expr.left, ctx)
-            val right = evaluate(expr.right, ctx)
-            return when(expr.operator) {
-                "<" -> RuntimeValue(DataType.UBYTE, if (left < right) 1 else 0)
-                "<=" -> RuntimeValue(DataType.UBYTE, if (left <= right) 1 else 0)
-                ">" -> RuntimeValue(DataType.UBYTE, if (left > right) 1 else 0)
-                ">=" -> RuntimeValue(DataType.UBYTE, if (left >= right) 1 else 0)
-                "==" -> RuntimeValue(DataType.UBYTE, if (left == right) 1 else 0)
-                "!=" -> RuntimeValue(DataType.UBYTE, if (left != right) 1 else 0)
-                "+" -> left.add(right)
-                "-" -> left.sub(right)
-                "*" -> left.mul(right)
-                "/" -> left.div(right)
-                "**" -> left.pow(right)
-                "<<" -> {
-                    var result = left
-                    repeat(right.integerValue()) {result = result.shl()}
-                    result
-                }
-                ">>" -> {
-                    var result = left
-                    repeat(right.integerValue()) {result = result.shr()}
-                    result
-                }
-                "%" -> left.remainder(right)
-                "|" -> left.bitor(right)
-                "&" -> left.bitand(right)
-                "^" -> left.bitxor(right)
-                "and" -> left.and(right)
-                "or" -> left.or(right)
-                "xor" -> left.xor(right)
-                else -> TODO("binexpression operator ${expr.operator}")
-            }
-        }
-        is ArrayIndexedExpression -> {
-            val array = evaluate(expr.identifier, ctx)
-            val index = evaluate(expr.arrayspec.index, ctx)
-            val value = array.array!![index.integerValue()]
-            return RuntimeValue(ArrayElementTypes.getValue(array.type), value)
-        }
-        is TypecastExpression -> {
-            return evaluate(expr.expression, ctx).cast(expr.type)
-        }
-        is AddressOf -> {
-            // we support: address of heap var -> the heap id
-            val heapId = expr.identifier.heapId(ctx.program.namespace)
-            return RuntimeValue(DataType.UWORD, heapId)
-        }
-        is DirectMemoryRead -> {
-            val address = evaluate(expr.addressExpression, ctx).wordval!!
-            return RuntimeValue(DataType.UBYTE, ctx.mem.getUByte(address))
-        }
-        is DirectMemoryWrite -> {
-            TODO("memorywrite $expr")
-        }
-        is RegisterExpr -> return ctx.runtimeVars.get(ctx.program.namespace, expr.register.name)
-        is IdentifierReference -> {
-            val scope = expr.definingScope()
-            val variable = scope.lookup(expr.nameInSource, expr)
-            if(variable is VarDecl) {
-                if(variable.type==VarDeclType.VAR)
-                    return ctx.runtimeVars.get(variable.definingScope(), variable.name)
-                else {
-                    val address = ctx.runtimeVars.getMemoryAddress(variable.definingScope(), variable.name)
-                    return when(variable.datatype) {
-                        DataType.UBYTE -> RuntimeValue(DataType.UBYTE, ctx.mem.getUByte(address))
-                        DataType.BYTE -> RuntimeValue(DataType.BYTE, ctx.mem.getSByte(address))
-                        DataType.UWORD -> RuntimeValue(DataType.UWORD, ctx.mem.getUWord(address))
-                        DataType.WORD -> RuntimeValue(DataType.WORD, ctx.mem.getSWord(address))
-                        DataType.FLOAT -> RuntimeValue(DataType.FLOAT, ctx.mem.getFloat(address))
-                        DataType.STR -> RuntimeValue(DataType.STR, str=ctx.mem.getString(address))
-                        DataType.STR_S -> RuntimeValue(DataType.STR_S, str=ctx.mem.getScreencodeString(address))
-                        else -> TODO("memvar $variable")
-                    }
-                }
-            } else
-                TODO("weird ref $variable")
-        }
-        is FunctionCall -> {
-            val sub = expr.target.targetStatement(ctx.program.namespace)
-            val args = expr.arglist.map { evaluate(it, ctx) }
-            return when(sub) {
-                is Subroutine -> {
-                    val results = ctx.executeSubroutine(sub, args, null)
-                    if(results.size!=1)
-                        throw VmExecutionException("expected 1 result from functioncall $expr")
-                    results[0]
-                }
-                is BuiltinFunctionStatementPlaceholder -> {
-                    val result = ctx.functions.performBuiltinFunction(sub.name, args, ctx.statusflags)
-                            ?: throw VmExecutionException("expected 1 result from functioncall $expr")
-                    result
-                }
-                else -> {
-                    TODO("call expr function ${expr.target}")
-                }
-            }
-        }
-        is RangeExpr -> {
-            val cRange = expr.toConstantIntegerRange()
-            if(cRange!=null)
-                return RuntimeValueRange(expr.inferType(ctx.program)!!, cRange)
-            val fromVal = evaluate(expr.from, ctx).integerValue()
-            val toVal = evaluate(expr.to, ctx).integerValue()
-            val stepVal = evaluate(expr.step, ctx).integerValue()
-            val range = when {
-                fromVal <= toVal -> when {
-                    stepVal <= 0 -> IntRange.EMPTY
-                    stepVal == 1 -> fromVal..toVal
-                    else -> fromVal..toVal step stepVal
-                }
-                else -> when {
-                    stepVal >= 0 -> IntRange.EMPTY
-                    stepVal == -1 -> fromVal downTo toVal
-                    else -> fromVal downTo toVal step abs(stepVal)
-                }
-            }
-            return RuntimeValueRange(expr.inferType(ctx.program)!!, range)
-        }
-        else -> {
-            TODO("implement eval $expr")
-        }
-    }
-}

compiler/src/prog8/astvm/Memory.kt

@@ -1,122 +0,0 @@
-package prog8.astvm
-
-import prog8.compiler.target.c64.Mflpt5
-import prog8.compiler.target.c64.Petscii
-import kotlin.math.abs
-
-class Memory {
-    private val mem = ShortArray(65536)         // shorts because byte is signed and we store values 0..255
-
-    fun getUByte(address: Int): Short {
-        return mem[address]
-    }
-
-    fun getSByte(address: Int): Short {
-        val ubyte = getUByte(address)
-        if(ubyte <= 127)
-            return ubyte
-        return (-((ubyte.toInt() xor 255)+1)).toShort()   // 2's complement
-    }
-
-    fun setUByte(address: Int, value: Short) {
-        if(value !in 0..255)
-            throw VmExecutionException("ubyte value out of range")
-        mem[address] = value
-    }
-
-    fun setSByte(address: Int, value: Short) {
-        if(value !in -128..127) throw VmExecutionException("byte value out of range")
-        if(value>=0)
-            mem[address] = value
-        else
-            mem[address] = ((abs(value.toInt()) xor 255)+1).toShort()        // 2's complement
-    }
-
-    fun getUWord(address: Int): Int {
-        return mem[address] + 256*mem[address+1]
-    }
-
-    fun getSWord(address: Int): Int {
-        val uword = getUWord(address)
-        if(uword <= 32767)
-            return uword
-        return -((uword xor 65535)+1)   // 2's complement
-    }
-
-    fun setUWord(address: Int, value: Int) {
-        if(value !in 0..65535)
-            throw VmExecutionException("uword value out of range")
-        mem[address] = value.and(255).toShort()
-        mem[address+1] = (value / 256).toShort()
-    }
-
-    fun setSWord(address: Int, value: Int) {
-        if(value !in -32768..32767) throw VmExecutionException("word value out of range")
-        if(value>=0)
-            setUWord(address, value)
-        else
-            setUWord(address, (abs(value) xor 65535)+1)        // 2's complement
-    }
-
-    fun setFloat(address: Int, value: Double) {
-        val mflpt5 = Mflpt5.fromNumber(value)
-        mem[address] = mflpt5.b0
-        mem[address+1] = mflpt5.b1
-        mem[address+2] = mflpt5.b2
-        mem[address+3] = mflpt5.b3
-        mem[address+4] = mflpt5.b4
-    }
-
-    fun getFloat(address: Int): Double {
-        return Mflpt5(mem[address], mem[address + 1], mem[address + 2], mem[address + 3], mem[address + 4]).toDouble()
-    }
-
-    fun setString(address: Int, str: String) {
-        // lowercase PETSCII
-        val petscii = Petscii.encodePetscii(str, true)
-        var addr = address
-        for (c in petscii) mem[addr++] = c
-        mem[addr] = 0
-    }
-
-    fun getString(strAddress: Int): String {
-        // lowercase PETSCII
-        val petscii = mutableListOf<Short>()
-        var addr = strAddress
-        while(true) {
-            val byte = mem[addr++]
-            if(byte==0.toShort()) break
-            petscii.add(byte)
-        }
-        return Petscii.decodePetscii(petscii, true)
-    }
-
-    fun clear() {
-        for(i in 0..65535) mem[i]=0
-    }
-
-    fun copy(from: Int, to: Int, numbytes: Int) {
-        for(i in 0 until numbytes)
-            mem[to+i] = mem[from+i]
-    }
-
-    fun getScreencodeString(strAddress: Int): String? {
-        // lowercase Screencodes
-        val screencodes = mutableListOf<Short>()
-        var addr = strAddress
-        while(true) {
-            val byte = mem[addr++]
-            if(byte==0.toShort()) break
-            screencodes.add(byte)
-        }
-        return Petscii.decodeScreencode(screencodes, true)
-    }
-
-    fun setScreencodeString(address: Int, str: String) {
-        // lowercase screencodes
-        val screencodes = Petscii.encodeScreencode(str, true)
-        var addr = address
-        for (c in screencodes) mem[addr++] = c
-        mem[addr] = 0
-    }
-}

compiler/src/prog8/astvm/VariablesCreator.kt

@@ -1,73 +0,0 @@
-package prog8.astvm
-
-import prog8.ast.*
-import prog8.compiler.HeapValues
-import prog8.compiler.RuntimeValue
-
-class VariablesCreator(private val runtimeVariables: RuntimeVariables, private val heap: HeapValues) : IAstProcessor {
-
-    override fun process(program: Program) {
-        // define the three registers as global variables
-        runtimeVariables.define(program.namespace, Register.A.name, RuntimeValue(DataType.UBYTE, 0))
-        runtimeVariables.define(program.namespace, Register.X.name, RuntimeValue(DataType.UBYTE, 255))
-        runtimeVariables.define(program.namespace, Register.Y.name, RuntimeValue(DataType.UBYTE, 0))
-
-        val globalpos = Position("<<global>>", 0, 0, 0)
-        val vdA = VarDecl(VarDeclType.VAR, DataType.UBYTE, false, null, Register.A.name, LiteralValue.optimalInteger(0, globalpos), isArray = false, autoGenerated = true, position = globalpos)
-        val vdX = VarDecl(VarDeclType.VAR, DataType.UBYTE, false, null, Register.X.name, LiteralValue.optimalInteger(255, globalpos), isArray = false, autoGenerated = true, position = globalpos)
-        val vdY = VarDecl(VarDeclType.VAR, DataType.UBYTE, false, null, Register.Y.name, LiteralValue.optimalInteger(0, globalpos), isArray = false, autoGenerated = true, position = globalpos)
-        vdA.linkParents(program.namespace)
-        vdX.linkParents(program.namespace)
-        vdY.linkParents(program.namespace)
-        program.namespace.statements.add(vdA)
-        program.namespace.statements.add(vdX)
-        program.namespace.statements.add(vdY)
-
-        super.process(program)
-    }
-
-    override fun process(decl: VarDecl): IStatement {
-        when(decl.type) {
-            VarDeclType.VAR -> {
-                val value = when (decl.datatype) {
-                    in NumericDatatypes -> {
-                        if(decl.value !is LiteralValue) {
-                            TODO("evaluate vardecl expression $decl")
-                            //RuntimeValue(decl.datatype, num = evaluate(decl.value!!, program, runtimeVariables, executeSubroutine).numericValue())
-                        } else {
-                            RuntimeValue.from(decl.value as LiteralValue, heap)
-                        }
-                    }
-                    in StringDatatypes -> {
-                        RuntimeValue.from(decl.value as LiteralValue, heap)
-                    }
-                    in ArrayDatatypes -> {
-                        RuntimeValue.from(decl.value as LiteralValue, heap)
-                    }
-                    else -> throw VmExecutionException("weird type ${decl.datatype}")
-                }
-                runtimeVariables.define(decl.definingScope(), decl.name, value)
-            }
-            VarDeclType.MEMORY -> {
-                if(decl.value !is LiteralValue) {
-                    TODO("evaluate vardecl expression $decl")
-                    //RuntimeValue(decl.datatype, num = evaluate(decl.value!!, program, runtimeVariables, executeSubroutine).numericValue())
-                } else {
-                    runtimeVariables.defineMemory(decl.definingScope(), decl.name, (decl.value as LiteralValue).asIntegerValue!!)
-                }
-            }
-            VarDeclType.CONST -> {
-                // consts should have been const-folded away
-            }
-        }
-        return super.process(decl)
-    }
-
-//    override fun process(assignment: Assignment): IStatement {
-//        if(assignment is VariableInitializationAssignment) {
-//            println("INIT VAR $assignment")
-//        }
-//        return super.process(assignment)
-//    }
-
-}

compiler/src/prog8/compiler/AssemblyError.kt

@@ -0,0 +1,3 @@
+package prog8.compiler
+
+internal class AssemblyError(msg: String) : RuntimeException(msg)

compiler/src/prog8/compiler/Main.kt

@@ -0,0 +1,179 @@
+package prog8.compiler
+
+import prog8.ast.AstToSourceCode
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.statements.Directive
+import prog8.compiler.target.CompilationTarget
+import prog8.optimizer.constantFold
+import prog8.optimizer.optimizeStatements
+import prog8.optimizer.simplifyExpressions
+import prog8.parser.ParsingFailedError
+import prog8.parser.importLibraryModule
+import prog8.parser.importModule
+import prog8.parser.moduleName
+import java.nio.file.Path
+import kotlin.system.measureTimeMillis
+
+
+class CompilationResult(val success: Boolean,
+                        val programAst: Program,
+                        val programName: String,
+                        val importedFiles: List<Path>)
+
+
+fun compileProgram(filepath: Path,
+                   optimize: Boolean,
+                   writeAssembly: Boolean,
+                   outputDir: Path): CompilationResult {
+    lateinit var programAst: Program
+    var programName: String? = null
+
+    var importedFiles: List<Path> = emptyList()
+    var success=false
+
+    try {
+        val totalTime = measureTimeMillis {
+            // import main module and everything it needs
+            println("Parsing...")
+            programAst = Program(moduleName(filepath.fileName), mutableListOf())
+            importModule(programAst, filepath)
+
+            importedFiles = programAst.modules.filter { !it.source.startsWith("@embedded@") }.map{ it.source }
+
+            val compilerOptions = determineCompilationOptions(programAst)
+            if (compilerOptions.launcher == LauncherType.BASIC && compilerOptions.output != OutputType.PRG)
+                throw ParsingFailedError("${programAst.modules.first().position} BASIC launcher requires output type PRG.")
+
+            // if we're producing a PRG or BASIC program, include the c64utils and c64lib libraries
+            if (compilerOptions.launcher == LauncherType.BASIC || compilerOptions.output == OutputType.PRG) {
+                importLibraryModule(programAst, "c64lib")
+                importLibraryModule(programAst, "c64utils")
+            }
+
+            // always import prog8lib and math
+            importLibraryModule(programAst, "math")
+            importLibraryModule(programAst, "prog8lib")
+
+
+            // perform initial syntax checks and constant folding
+            println("Syntax check...")
+            val time1 = measureTimeMillis {
+                programAst.checkIdentifiers()
+            }
+
+            //println(" time1: $time1")
+            val time2 = measureTimeMillis {
+                programAst.constantFold()
+            }
+            //println(" time2: $time2")
+            val time3 = measureTimeMillis {
+                programAst.removeNopsFlattenAnonScopes()
+                programAst.reorderStatements()
+                programAst.addTypecasts()
+            }
+            //println(" time3: $time3")
+            val time4 = measureTimeMillis {
+                programAst.checkValid(compilerOptions)          // check if tree is valid
+            }
+            //println(" time4: $time4")
+
+            programAst.checkIdentifiers()
+            if (optimize) {
+                // optimize the parse tree
+                println("Optimizing...")
+                while (true) {
+                    // keep optimizing expressions and statements until no more steps remain
+                    val optsDone1 = programAst.simplifyExpressions()
+                    val optsDone2 = programAst.optimizeStatements()
+                    if (optsDone1 + optsDone2 == 0)
+                        break
+                }
+            }
+
+            programAst.addTypecasts()
+            programAst.removeNopsFlattenAnonScopes()
+            programAst.checkValid(compilerOptions)          // check if final tree is valid
+            programAst.checkRecursion()         // check if there are recursive subroutine calls
+
+            // printAst(programAst)
+
+            if(writeAssembly) {
+                // asm generation directly from the Ast, no need for intermediate code
+                val zeropage = CompilationTarget.machine.getZeropage(compilerOptions)
+                programAst.anonscopeVarsCleanup()
+                val assembly = CompilationTarget.asmGenerator(programAst, zeropage, compilerOptions, outputDir).compileToAssembly(optimize)
+                assembly.assemble(compilerOptions)
+                programName = assembly.name
+            }
+            success = true
+        }
+        println("\nTotal compilation+assemble time: ${totalTime / 1000.0} sec.")
+
+    } catch (px: ParsingFailedError) {
+        System.err.print("\u001b[91m")  // bright red
+        System.err.println(px.message)
+        System.err.print("\u001b[0m")  // reset
+    } catch (ax: AstException) {
+        System.err.print("\u001b[91m")  // bright red
+        System.err.println(ax.toString())
+        System.err.print("\u001b[0m")  // reset
+    } catch (x: Exception) {
+        print("\u001b[91m")  // bright red
+        println("\n* internal error *")
+        print("\u001b[0m")  // reset
+        System.out.flush()
+        throw x
+    } catch (x: NotImplementedError) {
+        print("\u001b[91m")  // bright red
+        println("\n* internal error: missing feature/code *")
+        print("\u001b[0m")  // reset
+        System.out.flush()
+        throw x
+    }
+    return CompilationResult(success, programAst, programName ?: "", importedFiles)
+}
+
+fun printAst(programAst: Program) {
+    println()
+    val printer = AstToSourceCode(::print, programAst)
+    printer.visit(programAst)
+    println()
+}
+
+
+private fun determineCompilationOptions(program: Program): CompilationOptions {
+    val mainModule = program.modules.first()
+    val outputType = (mainModule.statements.singleOrNull { it is Directive && it.directive == "%output" }
+            as? Directive)?.args?.single()?.name?.toUpperCase()
+    val launcherType = (mainModule.statements.singleOrNull { it is Directive && it.directive == "%launcher" }
+            as? Directive)?.args?.single()?.name?.toUpperCase()
+    mainModule.loadAddress = (mainModule.statements.singleOrNull { it is Directive && it.directive == "%address" }
+            as? Directive)?.args?.single()?.int ?: 0
+    val zpoption: String? = (mainModule.statements.singleOrNull { it is Directive && it.directive == "%zeropage" }
+            as? Directive)?.args?.single()?.name?.toUpperCase()
+    val allOptions = program.modules.flatMap { it.statements }.filter { it is Directive && it.directive == "%option" }.flatMap { (it as Directive).args }.toSet()
+    val floatsEnabled = allOptions.any { it.name == "enable_floats" }
+    val zpType: ZeropageType =
+            if (zpoption == null)
+                if(floatsEnabled) ZeropageType.FLOATSAFE else ZeropageType.KERNALSAFE
+            else
+                try {
+                    ZeropageType.valueOf(zpoption)
+                } catch (x: IllegalArgumentException) {
+                    ZeropageType.KERNALSAFE
+                    // error will be printed by the astchecker
+                }
+    val zpReserved = mainModule.statements
+            .asSequence()
+            .filter { it is Directive && it.directive == "%zpreserved" }
+            .map { (it as Directive).args }
+            .map { it[0].int!!..it[1].int!! }
+            .toList()
+
+    return CompilationOptions(
+            if (outputType == null) OutputType.PRG else OutputType.valueOf(outputType),
+            if (launcherType == null) LauncherType.BASIC else LauncherType.valueOf(launcherType),
+            zpType, zpReserved, floatsEnabled
+    )
+}

compiler/src/prog8/compiler/RuntimeValue.kt

@@ -1,528 +0,0 @@
-package prog8.compiler
-
-import prog8.ast.*
-import prog8.compiler.target.c64.Petscii
-import kotlin.math.abs
-import kotlin.math.pow
-
-
-/**
- * Rather than a literal value (LiteralValue) that occurs in the parsed source code,
- * this runtime value can be used to *execute* the parsed Ast (or another intermediary form)
- * It contains a value of a variable during run time of the program and provides arithmetic operations on the value.
- */
-open class RuntimeValue(val type: DataType, num: Number?=null, val str: String?=null, val array: Array<Number>?=null, val heapId: Int?=null) {
-
-    val byteval: Short?
-    val wordval: Int?
-    val floatval: Double?
-    val asBoolean: Boolean
-
-    companion object {
-        fun from(literalValue: LiteralValue, heap: HeapValues): RuntimeValue {
-            return when(literalValue.type) {
-                in NumericDatatypes -> RuntimeValue(literalValue.type, num = literalValue.asNumericValue!!)
-                in StringDatatypes -> from(literalValue.heapId!!, heap)
-                in ArrayDatatypes -> from(literalValue.heapId!!, heap)
-                else -> TODO("type")
-            }
-        }
-
-        fun from(heapId: Int, heap: HeapValues): RuntimeValue {
-            val value = heap.get(heapId)
-            return when {
-                value.type in StringDatatypes ->
-                    RuntimeValue(value.type, str = value.str!!, heapId = heapId)
-                value.type in ArrayDatatypes ->
-                    if (value.type == DataType.ARRAY_F) {
-                        RuntimeValue(value.type, array = value.doubleArray!!.toList().toTypedArray(), heapId = heapId)
-                    } else {
-                        val array = value.array!!
-                        if (array.any { it.addressOf != null })
-                            TODO("addressof values")
-                        RuntimeValue(value.type, array = array.map { it.integer!! }.toTypedArray(), heapId = heapId)
-                    }
-                else -> TODO("weird type on heap")
-            }
-        }
-
-    }
-
-    init {
-        when(type) {
-            DataType.UBYTE -> {
-                byteval = (num!!.toInt() and 255).toShort()
-                wordval = null
-                floatval = null
-                asBoolean = byteval != 0.toShort()
-            }
-            DataType.BYTE -> {
-                val v = num!!.toInt() and 255
-                byteval = (if(v<128) v else v-256).toShort()
-                wordval = null
-                floatval = null
-                asBoolean = byteval != 0.toShort()
-            }
-            DataType.UWORD -> {
-                wordval = num!!.toInt() and 65535
-                byteval = null
-                floatval = null
-                asBoolean = wordval != 0
-            }
-            DataType.WORD -> {
-                val v = num!!.toInt() and 65535
-                wordval = if(v<32768) v else v - 65536
-                byteval = null
-                floatval = null
-                asBoolean = wordval != 0
-            }
-            DataType.FLOAT -> {
-                floatval = num!!.toDouble()
-                byteval = null
-                wordval = null
-                asBoolean = floatval != 0.0
-            }
-            else -> {
-                if(heapId==null)
-                    throw IllegalArgumentException("for non-numeric types, a heapId should be given")
-                byteval = null
-                wordval = null
-                floatval = null
-                asBoolean = true
-            }
-        }
-    }
-
-    fun asLiteralValue(): LiteralValue {
-        return when(type) {
-            in ByteDatatypes -> LiteralValue(type, byteval, position = Position("", 0, 0, 0))
-            in WordDatatypes -> LiteralValue(type, wordvalue = wordval, position = Position("", 0, 0, 0))
-            DataType.FLOAT -> LiteralValue(type, floatvalue = floatval, position = Position("", 0, 0, 0))
-            in StringDatatypes -> LiteralValue(type, strvalue = str, position = Position("", 0, 0, 0))
-            in ArrayDatatypes -> LiteralValue(type,
-                    arrayvalue = array?.map { LiteralValue.optimalNumeric(it, Position("", 0, 0, 0)) }?.toTypedArray(),
-                    position = Position("", 0, 0, 0))
-            else -> TODO("strange type")
-        }
-    }
-
-    override fun toString(): String {
-        return when(type) {
-            DataType.UBYTE -> "ub:%02x".format(byteval)
-            DataType.BYTE -> {
-                if(byteval!!<0)
-                    "b:-%02x".format(abs(byteval.toInt()))
-                else
-                    "b:%02x".format(byteval)
-            }
-            DataType.UWORD -> "uw:%04x".format(wordval)
-            DataType.WORD -> {
-                if(wordval!!<0)
-                    "w:-%04x".format(abs(wordval))
-                else
-                    "w:%04x".format(wordval)
-            }
-            DataType.FLOAT -> "f:$floatval"
-            else -> "heap:$heapId"
-        }
-    }
-
-    fun numericValue(): Number {
-        return when(type) {
-            in ByteDatatypes -> byteval!!
-            in WordDatatypes -> wordval!!
-            DataType.FLOAT -> floatval!!
-            else -> throw ArithmeticException("invalid datatype for numeric value: $type")
-        }
-    }
-
-    fun integerValue(): Int {
-        return when(type) {
-            in ByteDatatypes -> byteval!!.toInt()
-            in WordDatatypes -> wordval!!
-            DataType.FLOAT -> throw ArithmeticException("float to integer loss of precision")
-            else -> throw ArithmeticException("invalid datatype for integer value: $type")
-        }
-    }
-
-    override fun hashCode(): Int {
-        val bh = byteval?.hashCode() ?: 0x10001234
-        val wh = wordval?.hashCode() ?: 0x01002345
-        val fh = floatval?.hashCode() ?: 0x00103456
-        return bh xor wh xor fh xor heapId.hashCode() xor type.hashCode()
-    }
-
-    override fun equals(other: Any?): Boolean {
-        if(other==null || other !is RuntimeValue)
-            return false
-        if(type==other.type)
-            return if (type in IterableDatatypes) heapId==other.heapId else compareTo(other)==0
-        return compareTo(other)==0      // note: datatype doesn't matter
-    }
-
-    operator fun compareTo(other: RuntimeValue): Int {
-        return if (type in NumericDatatypes && other.type in NumericDatatypes)
-            numericValue().toDouble().compareTo(other.numericValue().toDouble())
-        else throw ArithmeticException("comparison can only be done between two numeric values")
-    }
-
-    private fun arithResult(leftDt: DataType, result: Number, rightDt: DataType, op: String): RuntimeValue {
-        if(leftDt!=rightDt)
-            throw ArithmeticException("left and right datatypes are not the same")
-        if(result.toDouble() < 0 ) {
-            return when(leftDt) {
-                DataType.UBYTE, DataType.UWORD -> {
-                    // storing a negative number in an unsigned one is done by storing the 2's complement instead
-                    val number = abs(result.toDouble().toInt())
-                    if(leftDt==DataType.UBYTE)
-                        RuntimeValue(DataType.UBYTE, (number xor 255) + 1)
-                    else
-                        RuntimeValue(DataType.UBYTE, (number xor 65535) + 1)
-                }
-                DataType.BYTE -> RuntimeValue(DataType.BYTE, result.toInt())
-                DataType.WORD -> RuntimeValue(DataType.WORD, result.toInt())
-                DataType.FLOAT -> RuntimeValue(DataType.FLOAT, result)
-                else -> throw ArithmeticException("$op on non-numeric type")
-            }
-        }
-
-        return when(leftDt) {
-            DataType.UBYTE -> RuntimeValue(DataType.UBYTE, result.toInt())
-            DataType.BYTE -> RuntimeValue(DataType.BYTE, result.toInt())
-            DataType.UWORD -> RuntimeValue(DataType.UWORD, result.toInt())
-            DataType.WORD -> RuntimeValue(DataType.WORD, result.toInt())
-            DataType.FLOAT -> RuntimeValue(DataType.FLOAT, result)
-            else -> throw ArithmeticException("$op on non-numeric type")
-        }
-    }
-
-    fun add(other: RuntimeValue): RuntimeValue {
-        if(other.type == DataType.FLOAT && (type!= DataType.FLOAT))
-            throw ArithmeticException("floating point loss of precision on type $type")
-        val v1 = numericValue()
-        val v2 = other.numericValue()
-        val result = v1.toDouble() + v2.toDouble()
-        return arithResult(type, result, other.type, "add")
-    }
-
-    fun sub(other: RuntimeValue): RuntimeValue {
-        if(other.type == DataType.FLOAT && (type!= DataType.FLOAT))
-            throw ArithmeticException("floating point loss of precision on type $type")
-        val v1 = numericValue()
-        val v2 = other.numericValue()
-        val result = v1.toDouble() - v2.toDouble()
-        return arithResult(type, result, other.type, "sub")
-    }
-
-    fun mul(other: RuntimeValue): RuntimeValue {
-        if(other.type == DataType.FLOAT && (type!= DataType.FLOAT))
-            throw ArithmeticException("floating point loss of precision on type $type")
-        val v1 = numericValue()
-        val v2 = other.numericValue()
-        val result = v1.toDouble() * v2.toDouble()
-        return arithResult(type, result, other.type, "mul")
-    }
-
-    fun div(other: RuntimeValue): RuntimeValue {
-        if(other.type == DataType.FLOAT && (type!= DataType.FLOAT))
-            throw ArithmeticException("floating point loss of precision on type $type")
-        val v1 = numericValue()
-        val v2 = other.numericValue()
-        if(v2.toDouble()==0.0) {
-            when (type) {
-                DataType.UBYTE -> return RuntimeValue(DataType.UBYTE, 255)
-                DataType.BYTE -> return RuntimeValue(DataType.BYTE, 127)
-                DataType.UWORD -> return RuntimeValue(DataType.UWORD, 65535)
-                DataType.WORD -> return RuntimeValue(DataType.WORD, 32767)
-                else -> {}
-            }
-        }
-        val result = v1.toDouble() / v2.toDouble()
-        // NOTE: integer division returns integer result!
-        return when(type) {
-            DataType.UBYTE -> RuntimeValue(DataType.UBYTE, result)
-            DataType.BYTE -> RuntimeValue(DataType.BYTE, result)
-            DataType.UWORD -> RuntimeValue(DataType.UWORD, result)
-            DataType.WORD -> RuntimeValue(DataType.WORD, result)
-            DataType.FLOAT -> RuntimeValue(DataType.FLOAT, result)
-            else -> throw ArithmeticException("div on non-numeric type")
-        }
-    }
-
-    fun remainder(other: RuntimeValue): RuntimeValue {
-        val v1 = numericValue()
-        val v2 = other.numericValue()
-        val result = v1.toDouble() % v2.toDouble()
-        return arithResult(type, result, other.type, "remainder")
-    }
-
-    fun pow(other: RuntimeValue): RuntimeValue {
-        val v1 = numericValue()
-        val v2 = other.numericValue()
-        val result = v1.toDouble().pow(v2.toDouble())
-        return arithResult(type, result, other.type,"pow")
-    }
-
-    fun shl(): RuntimeValue {
-        val v = integerValue()
-        return when (type) {
-            DataType.UBYTE,
-            DataType.BYTE,
-            DataType.UWORD,
-            DataType.WORD -> RuntimeValue(type, v shl 1)
-            else -> throw ArithmeticException("invalid type for shl: $type")
-        }
-    }
-
-    fun shr(): RuntimeValue {
-        val v = integerValue()
-        return when(type){
-            DataType.UBYTE -> RuntimeValue(type, v ushr 1)
-            DataType.BYTE -> RuntimeValue(type, v shr 1)
-            DataType.UWORD -> RuntimeValue(type, v ushr 1)
-            DataType.WORD -> RuntimeValue(type, v shr 1)
-            else -> throw ArithmeticException("invalid type for shr: $type")
-        }
-    }
-
-    fun rol(carry: Boolean): Pair<RuntimeValue, Boolean> {
-        // 9 or 17 bit rotate left (with carry))
-        return when(type) {
-            DataType.UBYTE, DataType.BYTE -> {
-                val v = byteval!!.toInt()
-                val newCarry = (v and 0x80) != 0
-                val newval = (v and 0x7f shl 1) or (if(carry) 1 else 0)
-                Pair(RuntimeValue(DataType.UBYTE, newval), newCarry)
-            }
-            DataType.UWORD, DataType.WORD -> {
-                val v = wordval!!
-                val newCarry = (v and 0x8000) != 0
-                val newval = (v and 0x7fff shl 1) or (if(carry) 1 else 0)
-                Pair(RuntimeValue(DataType.UWORD, newval), newCarry)
-            }
-            else -> throw ArithmeticException("rol can only work on byte/word")
-        }
-    }
-
-    fun ror(carry: Boolean): Pair<RuntimeValue, Boolean> {
-        // 9 or 17 bit rotate right (with carry)
-        return when(type) {
-            DataType.UBYTE, DataType.BYTE -> {
-                val v = byteval!!.toInt()
-                val newCarry = v and 1 != 0
-                val newval = (v ushr 1) or (if(carry) 0x80 else 0)
-                Pair(RuntimeValue(DataType.UBYTE, newval), newCarry)
-            }
-            DataType.UWORD, DataType.WORD -> {
-                val v = wordval!!
-                val newCarry = v and 1 != 0
-                val newval = (v ushr 1) or (if(carry) 0x8000 else 0)
-                Pair(RuntimeValue(DataType.UWORD, newval), newCarry)
-            }
-            else -> throw ArithmeticException("ror2 can only work on byte/word")
-        }
-    }
-
-    fun rol2(): RuntimeValue {
-        // 8 or 16 bit rotate left
-        return when(type) {
-            DataType.UBYTE, DataType.BYTE -> {
-                val v = byteval!!.toInt()
-                val carry = (v and 0x80) ushr 7
-                val newval = (v and 0x7f shl 1) or carry
-                RuntimeValue(DataType.UBYTE, newval)
-            }
-            DataType.UWORD, DataType.WORD -> {
-                val v = wordval!!
-                val carry = (v and 0x8000) ushr 15
-                val newval = (v and 0x7fff shl 1) or carry
-                RuntimeValue(DataType.UWORD, newval)
-            }
-            else -> throw ArithmeticException("rol2 can only work on byte/word")
-        }
-    }
-
-    fun ror2(): RuntimeValue {
-        // 8 or 16 bit rotate right
-        return when(type) {
-            DataType.UBYTE, DataType.BYTE -> {
-                val v = byteval!!.toInt()
-                val carry = v and 1 shl 7
-                val newval = (v ushr 1) or carry
-                RuntimeValue(DataType.UBYTE, newval)
-            }
-            DataType.UWORD, DataType.WORD -> {
-                val v = wordval!!
-                val carry = v and 1 shl 15
-                val newval = (v ushr 1) or carry
-                RuntimeValue(DataType.UWORD, newval)
-            }
-            else -> throw ArithmeticException("ror2 can only work on byte/word")
-        }
-    }
-
-    fun neg(): RuntimeValue {
-        return when(type) {
-            DataType.BYTE -> RuntimeValue(DataType.BYTE, -(byteval!!))
-            DataType.WORD -> RuntimeValue(DataType.WORD, -(wordval!!))
-            DataType.FLOAT -> RuntimeValue(DataType.FLOAT, -(floatval)!!)
-            else -> throw ArithmeticException("neg can only work on byte/word/float")
-        }
-    }
-
-    fun abs(): RuntimeValue {
-        return when(type) {
-            DataType.BYTE -> RuntimeValue(DataType.BYTE, abs(byteval!!.toInt()))
-            DataType.WORD -> RuntimeValue(DataType.WORD, abs(wordval!!))
-            DataType.FLOAT -> RuntimeValue(DataType.FLOAT, abs(floatval!!))
-            else -> throw ArithmeticException("abs can only work on byte/word/float")
-        }
-    }
-
-    fun bitand(other: RuntimeValue): RuntimeValue {
-        val v1 = integerValue()
-        val v2 = other.integerValue()
-        val result = v1 and v2
-        return RuntimeValue(type, result)
-    }
-
-    fun bitor(other: RuntimeValue): RuntimeValue {
-        val v1 = integerValue()
-        val v2 = other.integerValue()
-        val result = v1 or v2
-        return RuntimeValue(type, result)
-    }
-
-    fun bitxor(other: RuntimeValue): RuntimeValue {
-        val v1 = integerValue()
-        val v2 = other.integerValue()
-        val result = v1 xor v2
-        return RuntimeValue(type, result)
-    }
-
-    fun and(other: RuntimeValue) = RuntimeValue(DataType.UBYTE, if (this.asBoolean && other.asBoolean) 1 else 0)
-    fun or(other: RuntimeValue) = RuntimeValue(DataType.UBYTE, if (this.asBoolean || other.asBoolean) 1 else 0)
-    fun xor(other: RuntimeValue) = RuntimeValue(DataType.UBYTE, if (this.asBoolean xor other.asBoolean) 1 else 0)
-    fun not() = RuntimeValue(DataType.UBYTE, if (this.asBoolean) 0 else 1)
-
-    fun inv(): RuntimeValue {
-        return when(type) {
-            in ByteDatatypes -> RuntimeValue(type, byteval!!.toInt().inv())
-            in WordDatatypes -> RuntimeValue(type, wordval!!.inv())
-            else -> throw ArithmeticException("inv can only work on byte/word")
-        }
-    }
-
-    fun inc(): RuntimeValue {
-        return when(type) {
-            in ByteDatatypes -> RuntimeValue(type, byteval!! + 1)
-            in WordDatatypes -> RuntimeValue(type, wordval!! + 1)
-            DataType.FLOAT -> RuntimeValue(DataType.FLOAT, floatval!! + 1)
-            else -> throw ArithmeticException("inc can only work on numeric types")
-        }
-    }
-
-    fun dec(): RuntimeValue {
-        return when(type) {
-            in ByteDatatypes -> RuntimeValue(type, byteval!! - 1)
-            in WordDatatypes -> RuntimeValue(type, wordval!! - 1)
-            DataType.FLOAT -> RuntimeValue(DataType.FLOAT, floatval!! - 1)
-            else -> throw ArithmeticException("dec can only work on numeric types")
-        }
-    }
-
-    fun msb(): RuntimeValue {
-        return when(type) {
-            in ByteDatatypes -> RuntimeValue(DataType.UBYTE, 0)
-            in WordDatatypes -> RuntimeValue(DataType.UBYTE, wordval!! ushr 8 and 255)
-            else -> throw ArithmeticException("msb can only work on (u)byte/(u)word")
-        }
-    }
-
-    fun cast(targetType: DataType): RuntimeValue {
-        return when (type) {
-            DataType.UBYTE -> {
-                when (targetType) {
-                    DataType.UBYTE -> this
-                    DataType.BYTE -> RuntimeValue(DataType.BYTE, byteval)
-                    DataType.UWORD -> RuntimeValue(DataType.UWORD, numericValue())
-                    DataType.WORD -> RuntimeValue(DataType.WORD, numericValue())
-                    DataType.FLOAT -> RuntimeValue(DataType.FLOAT, numericValue())
-                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
-                }
-            }
-            DataType.BYTE -> {
-                when (targetType) {
-                    DataType.BYTE -> this
-                    DataType.UBYTE -> RuntimeValue(DataType.UBYTE, integerValue())
-                    DataType.UWORD -> RuntimeValue(DataType.UWORD, integerValue())
-                    DataType.WORD -> RuntimeValue(DataType.WORD, integerValue())
-                    DataType.FLOAT -> RuntimeValue(DataType.FLOAT, numericValue())
-                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
-                }
-            }
-            DataType.UWORD -> {
-                when (targetType) {
-                    DataType.BYTE -> RuntimeValue(DataType.BYTE, integerValue())
-                    DataType.UBYTE -> RuntimeValue(DataType.UBYTE, integerValue())
-                    DataType.UWORD -> this
-                    DataType.WORD -> RuntimeValue(DataType.WORD, integerValue())
-                    DataType.FLOAT -> RuntimeValue(DataType.FLOAT, numericValue())
-                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
-                }
-            }
-            DataType.WORD -> {
-                when (targetType) {
-                    DataType.BYTE -> RuntimeValue(DataType.BYTE, integerValue())
-                    DataType.UBYTE -> RuntimeValue(DataType.UBYTE, integerValue())
-                    DataType.UWORD -> RuntimeValue(DataType.UWORD, integerValue())
-                    DataType.WORD -> this
-                    DataType.FLOAT -> RuntimeValue(DataType.FLOAT, numericValue())
-                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
-                }
-            }
-            DataType.FLOAT -> {
-                when (targetType) {
-                    DataType.BYTE -> {
-                        val integer=numericValue().toInt()
-                        if(integer in -128..127)
-                            RuntimeValue(DataType.BYTE, integer)
-                        else
-                            throw ArithmeticException("overflow when casting float to byte: $this")
-                    }
-                    DataType.UBYTE -> RuntimeValue(DataType.UBYTE, numericValue().toInt())
-                    DataType.UWORD -> RuntimeValue(DataType.UWORD, numericValue().toInt())
-                    DataType.WORD -> {
-                        val integer=numericValue().toInt()
-                        if(integer in -32768..32767)
-                            RuntimeValue(DataType.WORD, integer)
-                        else
-                            throw ArithmeticException("overflow when casting float to word: $this")
-                    }
-                    DataType.FLOAT -> this
-                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
-                }
-            }
-            else -> throw ArithmeticException("invalid type cast from $type to $targetType")
-        }
-    }
-
-    open fun iterator(): Iterator<Number> {
-        return when (type) {
-            in StringDatatypes -> {
-                Petscii.encodePetscii(str!!, true).iterator()
-            }
-            in ArrayDatatypes -> {
-                array!!.iterator()
-            }
-            else -> throw IllegalArgumentException("cannot iterate over $this")
-        }
-    }
-}
-
-
-class RuntimeValueRange(type: DataType, val range: IntProgression): RuntimeValue(type, 0) {
-    override fun iterator(): Iterator<Number> {
-        return range.iterator()
-    }
-}

compiler/src/prog8/compiler/Zeropage.kt

@@ -1,6 +1,6 @@
 package prog8.compiler
 
-import prog8.ast.*
+import prog8.ast.base.*
 
 
 class ZeropageDepletedError(message: String) : Exception(message)
@@ -13,11 +13,14 @@ abstract class Zeropage(protected val options: CompilationOptions) {
 
     val allowedDatatypes = NumericDatatypes
 
-    fun available() = free.size
+    fun available() = if(options.zeropage==ZeropageType.DONTUSE) 0 else free.size
 
     fun allocate(scopedname: String, datatype: DataType, position: Position?): Int {
         assert(scopedname.isEmpty() || !allocations.values.any { it.first==scopedname } ) {"isSameAs scopedname can't be allocated twice"}
 
+        if(options.zeropage==ZeropageType.DONTUSE)
+            throw CompilerException("zero page usage has been disabled")
+
         val size =
                 when (datatype) {
                     in ByteDatatypes -> 1

compiler/src/prog8/compiler/intermediate/Instruction.kt

@@ -1,51 +0,0 @@
-package prog8.compiler.intermediate
-
-import prog8.compiler.RuntimeValue
-import prog8.stackvm.Syscall
-
-open class Instruction(val opcode: Opcode,
-                       val arg: RuntimeValue? = null,
-                       val arg2: RuntimeValue? = null,
-                       val callLabel: String? = null,
-                       val callLabel2: String? = null)
-{
-    var branchAddress: Int? = null
-
-    override fun toString(): String {
-        val argStr = arg?.toString() ?: ""
-        val result =
-                when {
-                    opcode==Opcode.LINE -> "_line  $callLabel"
-                    opcode==Opcode.INLINE_ASSEMBLY -> {
-                        // inline assembly is not written out (it can't be processed as intermediate language)
-                        // instead, it is converted into a system call that can be intercepted by the vm
-                        if(callLabel!=null)
-                            "syscall  SYSASM.$callLabel\n    return"
-                        else
-                            "inline_assembly"
-                    }
-                    opcode==Opcode.INCLUDE_FILE -> {
-                        "include_file \"$callLabel\" $arg $arg2"
-                    }
-                    opcode==Opcode.SYSCALL -> {
-                        val syscall = Syscall.values().find { it.callNr==arg!!.numericValue() }
-                        "syscall  $syscall"
-                    }
-                    opcode in opcodesWithVarArgument -> {
-                        // opcodes that manipulate a variable
-                        "${opcode.name.toLowerCase()}  ${callLabel?:""}  ${callLabel2?:""}".trimEnd()
-                    }
-                    callLabel==null -> "${opcode.name.toLowerCase()}  $argStr"
-                    else -> "${opcode.name.toLowerCase()}  $callLabel  $argStr"
-                }
-                .trimEnd()
-
-        return "    $result"
-    }
-}
-
-class LabelInstr(val name: String, val asmProc: Boolean) : Instruction(Opcode.NOP, null, null) {
-    override fun toString(): String {
-        return "\n$name:"
-    }
-}

compiler/src/prog8/compiler/intermediate/IntermediateProgram.kt

@@ -1,520 +0,0 @@
-package prog8.compiler.intermediate
-
-import prog8.ast.*
-import prog8.compiler.RuntimeValue
-import prog8.compiler.CompilerException
-import prog8.compiler.HeapValues
-import prog8.compiler.Zeropage
-import prog8.compiler.ZeropageDepletedError
-import java.io.PrintStream
-import java.nio.file.Path
-
-
-class IntermediateProgram(val name: String, var loadAddress: Int, val heap: HeapValues, val source: Path) {
-
-    class ProgramBlock(val name: String,
-                       var address: Int?,
-                       val instructions: MutableList<Instruction> = mutableListOf(),
-                       val variables: MutableMap<String, RuntimeValue> = mutableMapOf(),           // names are fully scoped
-                       val memoryPointers: MutableMap<String, Pair<Int, DataType>> = mutableMapOf(),
-                       val labels: MutableMap<String, Instruction> = mutableMapOf(),        // names are fully scoped
-                       val force_output: Boolean)
-    {
-        val numVariables: Int
-            get() { return variables.size }
-        val numInstructions: Int
-            get() { return instructions.filter { it.opcode!= Opcode.LINE }.size }
-        val variablesMarkedForZeropage: MutableSet<String> = mutableSetOf()
-    }
-
-    val allocatedZeropageVariables = mutableMapOf<String, Pair<Int, DataType>>()
-    val blocks = mutableListOf<ProgramBlock>()
-    val memory = mutableMapOf<Int, List<RuntimeValue>>()
-    private lateinit var currentBlock: ProgramBlock
-
-    val numVariables: Int
-        get() = blocks.sumBy { it.numVariables }
-    val numInstructions: Int
-        get() = blocks.sumBy { it.numInstructions }
-
-    fun allocateZeropage(zeropage: Zeropage) {
-        // allocates all @zp marked variables on the zeropage (for all blocks, as long as there is space in the ZP)
-        var notAllocated = 0
-        for(block in blocks) {
-            val zpVariables = block.variables.filter { it.key in block.variablesMarkedForZeropage }
-            if (zpVariables.isNotEmpty()) {
-                for (variable in zpVariables) {
-                    try {
-                        val address = zeropage.allocate(variable.key, variable.value.type, null)
-                        allocatedZeropageVariables[variable.key] = Pair(address, variable.value.type)
-                    } catch (x: ZeropageDepletedError) {
-                        printWarning(x.toString() + " variable ${variable.key} type ${variable.value.type}")
-                        notAllocated++
-                    }
-                }
-            }
-        }
-        if(notAllocated>0)
-            printWarning("$notAllocated variables marked for Zeropage could not be allocated there")
-    }
-
-    fun optimize() {
-        println("Optimizing stackVM code...")
-        // remove nops (that are not a label)
-        for (blk in blocks) {
-            blk.instructions.removeIf { it.opcode== Opcode.NOP && it !is LabelInstr }
-        }
-
-        optimizeDataConversionAndUselessDiscards()
-        optimizeVariableCopying()
-        optimizeMultipleSequentialLineInstrs()
-        optimizeCallReturnIntoJump()
-        optimizeConditionalBranches()
-        // todo: add more optimizations to intermediate code!
-
-        optimizeRemoveNops()    //  must be done as the last step
-        optimizeMultipleSequentialLineInstrs()      // once more
-        optimizeRemoveNops()    // once more
-    }
-
-    private fun optimizeConditionalBranches() {
-        // conditional branches that consume the value on the stack
-        // sometimes these are just constant values, so we can statically determine the branch
-        // or, they are preceded by a NOT instruction so we can simply remove that and flip the branch condition
-        val pushvalue = setOf(Opcode.PUSH_BYTE, Opcode.PUSH_WORD)
-        val notvalue = setOf(Opcode.NOT_BYTE, Opcode.NOT_WORD)
-        val branchOpcodes = setOf(Opcode.JZ, Opcode.JNZ, Opcode.JZW, Opcode.JNZW)
-        for(blk in blocks) {
-            val instructionsToReplace = mutableMapOf<Int, Instruction>()
-            blk.instructions.asSequence().withIndex().filter {it.value.opcode!=Opcode.LINE}.windowed(2).toList().forEach {
-                if (it[1].value.opcode in branchOpcodes) {
-                    if (it[0].value.opcode in pushvalue) {
-                        val value = it[0].value.arg!!.asBoolean
-                        instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
-                        val replacement: Instruction =
-                                if (value) {
-                                    when (it[1].value.opcode) {
-                                        Opcode.JNZ -> Instruction(Opcode.JUMP, callLabel = it[1].value.callLabel)
-                                        Opcode.JNZW -> Instruction(Opcode.JUMP, callLabel = it[1].value.callLabel)
-                                        else -> Instruction(Opcode.NOP)
-                                    }
-                                } else {
-                                    when (it[1].value.opcode) {
-                                        Opcode.JZ -> Instruction(Opcode.JUMP, callLabel = it[1].value.callLabel)
-                                        Opcode.JZW -> Instruction(Opcode.JUMP, callLabel = it[1].value.callLabel)
-                                        else -> Instruction(Opcode.NOP)
-                                    }
-                                }
-                        instructionsToReplace[it[1].index] = replacement
-                    }
-                    else if (it[0].value.opcode in notvalue) {
-                        instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
-                        val replacement: Instruction =
-                                when (it[1].value.opcode) {
-                                    Opcode.JZ -> Instruction(Opcode.JNZ, callLabel = it[1].value.callLabel)
-                                    Opcode.JZW -> Instruction(Opcode.JNZW, callLabel = it[1].value.callLabel)
-                                    Opcode.JNZ -> Instruction(Opcode.JZ, callLabel = it[1].value.callLabel)
-                                    Opcode.JNZW -> Instruction(Opcode.JZW, callLabel = it[1].value.callLabel)
-                                    else -> Instruction(Opcode.NOP)
-                                }
-                        instructionsToReplace[it[1].index] = replacement
-                    }
-                }
-            }
-
-            for (rins in instructionsToReplace) {
-                blk.instructions[rins.key] = rins.value
-            }
-        }
-    }
-
-    private fun optimizeRemoveNops() {
-        // remove nops (that are not a label)
-        for (blk in blocks)
-            blk.instructions.removeIf { it.opcode== Opcode.NOP && it !is LabelInstr }
-    }
-
-    private fun optimizeCallReturnIntoJump() {
-        // replaces call X followed by return, by jump X
-        for(blk in blocks) {
-            val instructionsToReplace = mutableMapOf<Int, Instruction>()
-
-            blk.instructions.asSequence().withIndex().filter {it.value.opcode!=Opcode.LINE}.windowed(2).toList().forEach {
-                if(it[0].value.opcode==Opcode.CALL && it[1].value.opcode==Opcode.RETURN) {
-                    instructionsToReplace[it[1].index] = Instruction(Opcode.JUMP, callLabel = it[0].value.callLabel)
-                    instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
-                }
-            }
-
-            for (rins in instructionsToReplace) {
-                blk.instructions[rins.key] = rins.value
-            }
-        }
-    }
-
-    private fun optimizeMultipleSequentialLineInstrs() {
-        for(blk in blocks) {
-            val instructionsToReplace = mutableMapOf<Int, Instruction>()
-
-            blk.instructions.asSequence().withIndex().windowed(2).toList().forEach {
-                if (it[0].value.opcode == Opcode.LINE && it[1].value.opcode == Opcode.LINE)
-                    instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
-            }
-
-            for (rins in instructionsToReplace) {
-                blk.instructions[rins.key] = rins.value
-            }
-        }
-    }
-
-    private fun optimizeVariableCopying() {
-        for(blk in blocks) {
-
-            val instructionsToReplace = mutableMapOf<Int, Instruction>()
-
-            blk.instructions.asSequence().withIndex().windowed(2).toList().forEach {
-                when (it[0].value.opcode) {
-                    Opcode.PUSH_VAR_BYTE ->
-                        if (it[1].value.opcode == Opcode.POP_VAR_BYTE) {
-                            if (it[0].value.callLabel == it[1].value.callLabel) {
-                                instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
-                                instructionsToReplace[it[1].index] = Instruction(Opcode.NOP)
-                            }
-                        }
-                    Opcode.PUSH_VAR_WORD ->
-                        if (it[1].value.opcode == Opcode.POP_VAR_WORD) {
-                            if (it[0].value.callLabel == it[1].value.callLabel) {
-                                instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
-                                instructionsToReplace[it[1].index] = Instruction(Opcode.NOP)
-                            }
-                        }
-                    Opcode.PUSH_VAR_FLOAT ->
-                        if (it[1].value.opcode == Opcode.POP_VAR_FLOAT) {
-                            if (it[0].value.callLabel == it[1].value.callLabel) {
-                                instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
-                                instructionsToReplace[it[1].index] = Instruction(Opcode.NOP)
-                            }
-                        }
-                    Opcode.PUSH_MEM_B, Opcode.PUSH_MEM_UB ->
-                        if(it[1].value.opcode == Opcode.POP_MEM_BYTE) {
-                            if(it[0].value.arg == it[1].value.arg) {
-                                instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
-                                instructionsToReplace[it[1].index] = Instruction(Opcode.NOP)
-                            }
-                        }
-                    Opcode.PUSH_MEM_W, Opcode.PUSH_MEM_UW ->
-                        if(it[1].value.opcode == Opcode.POP_MEM_WORD) {
-                            if(it[0].value.arg == it[1].value.arg) {
-                                instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
-                                instructionsToReplace[it[1].index] = Instruction(Opcode.NOP)
-                            }
-                        }
-                    Opcode.PUSH_MEM_FLOAT ->
-                        if(it[1].value.opcode == Opcode.POP_MEM_FLOAT) {
-                            if(it[0].value.arg == it[1].value.arg) {
-                                instructionsToReplace[it[0].index] = Instruction(Opcode.NOP)
-                                instructionsToReplace[it[1].index] = Instruction(Opcode.NOP)
-                            }
-                        }
-                    else -> {}
-                }
-            }
-
-            for (rins in instructionsToReplace) {
-                blk.instructions[rins.key] = rins.value
-            }
-        }
-    }
-
-    private fun optimizeDataConversionAndUselessDiscards() {
-        // - push value followed by a data type conversion -> push the value in the correct type and remove the conversion
-        // - push something followed by a discard -> remove both
-        val instructionsToReplace = mutableMapOf<Int, Instruction>()
-
-        fun optimizeDiscardAfterPush(index0: Int, index1: Int, ins1: Instruction) {
-            if (ins1.opcode == Opcode.DISCARD_FLOAT || ins1.opcode == Opcode.DISCARD_WORD || ins1.opcode == Opcode.DISCARD_BYTE) {
-                instructionsToReplace[index0] = Instruction(Opcode.NOP)
-                instructionsToReplace[index1] = Instruction(Opcode.NOP)
-            }
-        }
-
-        fun optimizeFloatConversion(index0: Int, index1: Int, ins1: Instruction) {
-            when (ins1.opcode) {
-                Opcode.DISCARD_FLOAT -> {
-                    instructionsToReplace[index0] = Instruction(Opcode.NOP)
-                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                }
-                Opcode.DISCARD_BYTE, Opcode.DISCARD_WORD -> throw CompilerException("invalid discard type following a float")
-                else -> throw CompilerException("invalid conversion opcode ${ins1.opcode} following a float")
-            }
-        }
-
-        fun optimizeWordConversion(index0: Int, ins0: Instruction, index1: Int, ins1: Instruction) {
-            when (ins1.opcode) {
-                Opcode.CAST_UW_TO_B, Opcode.CAST_W_TO_B -> {
-                    val ins = Instruction(Opcode.PUSH_BYTE, ins0.arg!!.cast(DataType.BYTE))
-                    instructionsToReplace[index0] = ins
-                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                }
-                Opcode.CAST_W_TO_UB, Opcode.CAST_UW_TO_UB -> {
-                    val ins = Instruction(Opcode.PUSH_BYTE, RuntimeValue(DataType.UBYTE, ins0.arg!!.integerValue() and 255))
-                    instructionsToReplace[index0] = ins
-                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                }
-                Opcode.MSB -> {
-                    val ins = Instruction(Opcode.PUSH_BYTE, RuntimeValue(DataType.UBYTE, ins0.arg!!.integerValue() ushr 8 and 255))
-                    instructionsToReplace[index0] = ins
-                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                }
-                Opcode.CAST_W_TO_F, Opcode.CAST_UW_TO_F -> {
-                    val ins = Instruction(Opcode.PUSH_FLOAT, RuntimeValue(DataType.FLOAT, ins0.arg!!.integerValue().toDouble()))
-                    instructionsToReplace[index0] = ins
-                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                }
-                Opcode.CAST_UW_TO_W -> {
-                    val cv = ins0.arg!!.cast(DataType.WORD)
-                    instructionsToReplace[index0] = Instruction(Opcode.PUSH_WORD, cv)
-                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                }
-                Opcode.CAST_W_TO_UW -> {
-                    val cv = ins0.arg!!.cast(DataType.UWORD)
-                    instructionsToReplace[index0] = Instruction(Opcode.PUSH_WORD, cv)
-                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                }
-                Opcode.DISCARD_WORD -> {
-                    instructionsToReplace[index0] = Instruction(Opcode.NOP)
-                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                }
-                Opcode.DISCARD_BYTE, Opcode.DISCARD_FLOAT -> throw CompilerException("invalid discard type following a byte")
-                else -> throw CompilerException("invalid conversion opcode ${ins1.opcode} following a word")
-            }
-        }
-
-        fun optimizeByteConversion(index0: Int, ins0: Instruction, index1: Int, ins1: Instruction) {
-            when (ins1.opcode) {
-                Opcode.CAST_B_TO_UB, Opcode.CAST_UB_TO_B,
-                Opcode.CAST_W_TO_B, Opcode.CAST_W_TO_UB,
-                Opcode.CAST_UW_TO_B, Opcode.CAST_UW_TO_UB -> instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                Opcode.MSB -> throw CompilerException("msb of a byte")
-                Opcode.CAST_UB_TO_UW -> {
-                    val ins = Instruction(Opcode.PUSH_WORD, RuntimeValue(DataType.UWORD, ins0.arg!!.integerValue()))
-                    instructionsToReplace[index0] = ins
-                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                }
-                Opcode.CAST_B_TO_W -> {
-                    val ins = Instruction(Opcode.PUSH_WORD, RuntimeValue(DataType.WORD, ins0.arg!!.integerValue()))
-                    instructionsToReplace[index0] = ins
-                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                }
-                Opcode.CAST_B_TO_UW -> {
-                    val ins = Instruction(Opcode.PUSH_WORD, ins0.arg!!.cast(DataType.UWORD))
-                    instructionsToReplace[index0] = ins
-                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                }
-                Opcode.CAST_UB_TO_W -> {
-                    val ins = Instruction(Opcode.PUSH_WORD, ins0.arg!!.cast(DataType.WORD))
-                    instructionsToReplace[index0] = ins
-                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                }
-                Opcode.CAST_B_TO_F, Opcode.CAST_UB_TO_F-> {
-                    val ins = Instruction(Opcode.PUSH_FLOAT, RuntimeValue(DataType.FLOAT, ins0.arg!!.integerValue().toDouble()))
-                    instructionsToReplace[index0] = ins
-                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                }
-                Opcode.CAST_W_TO_F, Opcode.CAST_UW_TO_F-> throw CompilerException("invalid conversion following a byte")
-                Opcode.DISCARD_BYTE -> {
-                    instructionsToReplace[index0] = Instruction(Opcode.NOP)
-                    instructionsToReplace[index1] = Instruction(Opcode.NOP)
-                }
-                Opcode.DISCARD_WORD, Opcode.DISCARD_FLOAT -> throw CompilerException("invalid discard type following a byte")
-                Opcode.MKWORD -> {}
-                else -> throw CompilerException("invalid conversion opcode ${ins1.opcode}")
-            }
-        }
-
-        for(blk in blocks) {
-            instructionsToReplace.clear()
-
-            val typeConversionOpcodes = setOf(
-                    Opcode.MSB,
-                    Opcode.MKWORD,
-                    Opcode.CAST_UB_TO_B,
-                    Opcode.CAST_UB_TO_UW,
-                    Opcode.CAST_UB_TO_W,
-                    Opcode.CAST_UB_TO_F,
-                    Opcode.CAST_B_TO_UB,
-                    Opcode.CAST_B_TO_UW,
-                    Opcode.CAST_B_TO_W,
-                    Opcode.CAST_B_TO_F,
-                    Opcode.CAST_UW_TO_UB,
-                    Opcode.CAST_UW_TO_B,
-                    Opcode.CAST_UW_TO_W,
-                    Opcode.CAST_UW_TO_F,
-                    Opcode.CAST_W_TO_UB,
-                    Opcode.CAST_W_TO_B,
-                    Opcode.CAST_W_TO_UW,
-                    Opcode.CAST_W_TO_F,
-                    Opcode.CAST_F_TO_UB,
-                    Opcode.CAST_F_TO_B,
-                    Opcode.CAST_F_TO_UW,
-                    Opcode.CAST_F_TO_W,
-                    Opcode.DISCARD_BYTE,
-                    Opcode.DISCARD_WORD,
-                    Opcode.DISCARD_FLOAT
-            )
-            blk.instructions.asSequence().withIndex().windowed(2).toList().forEach {
-                if (it[1].value.opcode in typeConversionOpcodes) {
-                    when (it[0].value.opcode) {
-                        Opcode.PUSH_BYTE -> optimizeByteConversion(it[0].index, it[0].value, it[1].index, it[1].value)
-                        Opcode.PUSH_WORD -> optimizeWordConversion(it[0].index, it[0].value, it[1].index, it[1].value)
-                        Opcode.PUSH_FLOAT -> optimizeFloatConversion(it[0].index, it[1].index, it[1].value)
-                        Opcode.PUSH_VAR_FLOAT,
-                        Opcode.PUSH_VAR_WORD,
-                        Opcode.PUSH_VAR_BYTE,
-                        Opcode.PUSH_MEM_B, Opcode.PUSH_MEM_UB,
-                        Opcode.PUSH_MEM_W, Opcode.PUSH_MEM_UW,
-                        Opcode.PUSH_MEM_FLOAT -> optimizeDiscardAfterPush(it[0].index, it[1].index, it[1].value)
-                        else -> {
-                        }
-                    }
-                }
-            }
-
-            for (rins in instructionsToReplace) {
-                blk.instructions[rins.key] = rins.value
-            }
-        }
-    }
-
-    fun variable(scopedname: String, decl: VarDecl) {
-        when(decl.type) {
-            VarDeclType.VAR -> {
-                val value = when(decl.datatype) {
-                    in NumericDatatypes -> RuntimeValue(decl.datatype, (decl.value as LiteralValue).asNumericValue!!)
-                    in StringDatatypes -> {
-                        val litval = (decl.value as LiteralValue)
-                        if(litval.heapId==null)
-                            throw CompilerException("string should already be in the heap")
-                        RuntimeValue(decl.datatype, heapId = litval.heapId)
-                    }
-                    in ArrayDatatypes -> {
-                        val litval = (decl.value as LiteralValue)
-                        if(litval.heapId==null)
-                            throw CompilerException("array should already be in the heap")
-                        RuntimeValue(decl.datatype, heapId = litval.heapId)
-                    }
-                    else -> throw CompilerException("weird datatype")
-                }
-                currentBlock.variables[scopedname] = value
-                if(decl.zeropage)
-                    currentBlock.variablesMarkedForZeropage.add(scopedname)
-            }
-            VarDeclType.MEMORY -> {
-                // note that constants are all folded away, but assembly code may still refer to them
-                val lv = decl.value as LiteralValue
-                if(lv.type!=DataType.UWORD && lv.type!=DataType.UBYTE)
-                    throw CompilerException("expected integer memory address $lv")
-                currentBlock.memoryPointers[scopedname] = Pair(lv.asIntegerValue!!, decl.datatype)
-            }
-            VarDeclType.CONST -> {
-                // note that constants are all folded away, but assembly code may still refer to them (if their integers)
-                // floating point constants are not generated at all!!
-                val lv = decl.value as LiteralValue
-                if(lv.type in IntegerDatatypes)
-                    currentBlock.memoryPointers[scopedname] = Pair(lv.asIntegerValue!!, decl.datatype)
-            }
-        }
-    }
-
-    fun instr(opcode: Opcode, arg: RuntimeValue? = null, arg2: RuntimeValue? = null, callLabel: String? = null, callLabel2: String? = null) {
-        currentBlock.instructions.add(Instruction(opcode, arg, arg2, callLabel, callLabel2))
-    }
-
-    fun label(labelname: String, asmProc: Boolean=false) {
-        val instr = LabelInstr(labelname, asmProc)
-        currentBlock.instructions.add(instr)
-        currentBlock.labels[labelname] = instr
-    }
-
-    fun line(position: Position) {
-        currentBlock.instructions.add(Instruction(Opcode.LINE, callLabel = "${position.line} ${position.file}"))
-    }
-
-    fun removeLastInstruction() {
-        currentBlock.instructions.removeAt(currentBlock.instructions.lastIndex)
-    }
-
-    fun memoryPointer(name: String, address: Int, datatype: DataType) {
-        currentBlock.memoryPointers[name] = Pair(address, datatype)
-    }
-
-    fun newBlock(name: String, address: Int?, options: Set<String>) {
-        currentBlock = ProgramBlock(name, address, force_output="force_output" in options)
-        blocks.add(currentBlock)
-    }
-
-    fun writeCode(out: PrintStream, embeddedLabels: Boolean=true) {
-        out.println("; stackVM program code for '$name'")
-        out.println("%memory")
-        if(memory.isNotEmpty())
-            TODO("add support for writing/reading initial memory values")
-        out.println("%end_memory")
-        out.println("%heap")
-        heap.allEntries().forEach {
-            out.print("${it.key}  ${it.value.type.name.toLowerCase()}  ")
-            when {
-                it.value.str!=null ->
-                    out.println("\"${escape(it.value.str!!)}\"")
-                it.value.array!=null -> {
-                    // this array can contain both normal integers, and pointer values
-                    val arrayvalues = it.value.array!!.map { av ->
-                        when {
-                            av.integer!=null -> av.integer.toString()
-                            av.addressOf!=null -> {
-                                if(av.addressOf.scopedname==null)
-                                    throw CompilerException("AddressOf scopedname should have been set")
-                                else
-                                    "&${av.addressOf.scopedname}"
-                            }
-                            else -> throw CompilerException("weird array value")
-                        }
-                    }
-                    out.println(arrayvalues)
-                }
-                it.value.doubleArray!=null ->
-                    out.println(it.value.doubleArray!!.toList())
-                else -> throw CompilerException("invalid heap entry $it")
-            }
-        }
-        out.println("%end_heap")
-        for(blk in blocks) {
-            out.println("\n%block ${blk.name} ${blk.address?.toString(16) ?: ""}")
-
-            out.println("%variables")
-            for(variable in blk.variables) {
-                val valuestr = variable.value.toString()
-                out.println("${variable.key}  ${variable.value.type.name.toLowerCase()}  $valuestr")
-            }
-            out.println("%end_variables")
-            out.println("%memorypointers")
-            for(iconst in blk.memoryPointers) {
-                out.println("${iconst.key}  ${iconst.value.second.name.toLowerCase()}  uw:${iconst.value.first.toString(16)}")
-            }
-            out.println("%end_memorypointers")
-            out.println("%instructions")
-            val labels = blk.labels.entries.associateBy({it.value}) {it.key}
-            for(instr in blk.instructions) {
-                if(!embeddedLabels) {
-                    val label = labels[instr]
-                    if (label != null)
-                        out.println("$label:")
-                } else {
-                    out.println(instr)
-                }
-            }
-            out.println("%end_instructions")
-
-            out.println("%end_block")
-        }
-    }
-}

compiler/src/prog8/compiler/intermediate/Opcode.kt

@@ -1,289 +0,0 @@
-package prog8.compiler.intermediate
-
-enum class Opcode {
-
-    // pushing values on the (evaluation) stack
-    PUSH_BYTE,       // push byte value
-    PUSH_WORD,       // push word value   (or 'address' of string / array)
-    PUSH_FLOAT,      // push float value
-    PUSH_MEM_B,      // push byte value from memory to stack
-    PUSH_MEM_UB,     // push unsigned byte value from memory to stack
-    PUSH_MEM_W,      // push word value from memory to stack
-    PUSH_MEM_UW,     // push unsigned word value from memory to stack
-    PUSH_MEM_FLOAT,  // push float value from memory to stack
-    PUSH_MEMREAD,    // push memory value from address that's on the stack
-    PUSH_VAR_BYTE,   // push byte variable (ubyte, byte)
-    PUSH_VAR_WORD,   // push word variable (uword, word)
-    PUSH_VAR_FLOAT,  // push float variable
-    PUSH_REGAX_WORD, // push registers A/X as a 16-bit word
-    PUSH_REGAY_WORD, // push registers A/Y as a 16-bit word
-    PUSH_REGXY_WORD, // push registers X/Y as a 16-bit word
-    PUSH_ADDR_HEAPVAR,  // push the address of the variable that's on the heap (string or array)
-
-    // popping values off the (evaluation) stack, possibly storing them in another location
-    DISCARD_BYTE,    // discard top byte value
-    DISCARD_WORD,    // discard top word value
-    DISCARD_FLOAT,   // discard top float value
-    POP_MEM_BYTE,    // pop (u)byte value into destination memory address
-    POP_MEM_WORD,    // pop (u)word value into destination memory address
-    POP_MEM_FLOAT,   // pop float value into destination memory address
-    POP_MEMWRITE,    // pop address and byte stack and write the byte to the memory address
-    POP_VAR_BYTE,    // pop (u)byte value into variable
-    POP_VAR_WORD,    // pop (u)word value into variable
-    POP_VAR_FLOAT,   // pop float value into variable
-    POP_REGAX_WORD,  // pop uword from stack into A/X registers
-    POP_REGAY_WORD,  // pop uword from stack into A/Y registers
-    POP_REGXY_WORD,  // pop uword from stack into X/Y registers
-
-    // numeric arithmetic
-    ADD_UB,
-    ADD_B,
-    ADD_UW,
-    ADD_W,
-    ADD_F,
-    SUB_UB,
-    SUB_B,
-    SUB_UW,
-    SUB_W,
-    SUB_F,
-    MUL_UB,
-    MUL_B,
-    MUL_UW,
-    MUL_W,
-    MUL_F,
-    IDIV_UB,
-    IDIV_B,
-    IDIV_UW,
-    IDIV_W,
-    DIV_F,
-    REMAINDER_UB,   // signed remainder is undefined/unimplemented
-    REMAINDER_UW,   // signed remainder is undefined/unimplemented
-    POW_F,
-    NEG_B,
-    NEG_W,
-    NEG_F,
-    ABS_B,
-    ABS_W,
-    ABS_F,
-
-    // bit shifts and bitwise arithmetic
-    SHIFTEDL_BYTE,      // shifts stack value rather than in-place mem/var
-    SHIFTEDL_WORD,      // shifts stack value rather than in-place mem/var
-    SHIFTEDR_UBYTE,     // shifts stack value rather than in-place mem/var
-    SHIFTEDR_SBYTE,     // shifts stack value rather than in-place mem/var
-    SHIFTEDR_UWORD,     // shifts stack value rather than in-place mem/var
-    SHIFTEDR_SWORD,     // shifts stack value rather than in-place mem/var
-    SHL_BYTE,
-    SHL_WORD,
-    SHL_MEM_BYTE,
-    SHL_MEM_WORD,
-    SHL_VAR_BYTE,
-    SHL_VAR_WORD,
-    SHR_UBYTE,
-    SHR_SBYTE,
-    SHR_UWORD,
-    SHR_SWORD,
-    SHR_MEM_UBYTE,
-    SHR_MEM_SBYTE,
-    SHR_MEM_UWORD,
-    SHR_MEM_SWORD,
-    SHR_VAR_UBYTE,
-    SHR_VAR_SBYTE,
-    SHR_VAR_UWORD,
-    SHR_VAR_SWORD,
-    ROL_BYTE,
-    ROL_WORD,
-    ROL_MEM_BYTE,
-    ROL_MEM_WORD,
-    ROL_VAR_BYTE,
-    ROL_VAR_WORD,
-    ROR_BYTE,
-    ROR_WORD,
-    ROR_MEM_BYTE,
-    ROR_MEM_WORD,
-    ROR_VAR_BYTE,
-    ROR_VAR_WORD,
-    ROL2_BYTE,
-    ROL2_WORD,
-    ROL2_MEM_BYTE,
-    ROL2_MEM_WORD,
-    ROL2_VAR_BYTE,
-    ROL2_VAR_WORD,
-    ROR2_BYTE,
-    ROR2_WORD,
-    ROR2_MEM_BYTE,
-    ROR2_MEM_WORD,
-    ROR2_VAR_BYTE,
-    ROR2_VAR_WORD,
-    BITAND_BYTE,
-    BITAND_WORD,
-    BITOR_BYTE,
-    BITOR_WORD,
-    BITXOR_BYTE,
-    BITXOR_WORD,
-    INV_BYTE,
-    INV_WORD,
-
-    // numeric type conversions
-    MSB,        // note: lsb is equivalent to  CAST_UW_TO_UB  or CAST_W_TO_UB
-    MKWORD,        // create a word from lsb + msb
-    CAST_UB_TO_B,
-    CAST_UB_TO_UW,
-    CAST_UB_TO_W,
-    CAST_UB_TO_F,
-    CAST_B_TO_UB,
-    CAST_B_TO_UW,
-    CAST_B_TO_W,
-    CAST_B_TO_F,
-    CAST_W_TO_UB,
-    CAST_W_TO_B,
-    CAST_W_TO_UW,
-    CAST_W_TO_F,
-    CAST_UW_TO_UB,
-    CAST_UW_TO_B,
-    CAST_UW_TO_W,
-    CAST_UW_TO_F,
-    CAST_F_TO_UB,
-    CAST_F_TO_B,
-    CAST_F_TO_UW,
-    CAST_F_TO_W,
-
-    // logical operations
-    AND_BYTE,
-    AND_WORD,
-    OR_BYTE,
-    OR_WORD,
-    XOR_BYTE,
-    XOR_WORD,
-    NOT_BYTE,
-    NOT_WORD,
-
-    // increment, decrement
-    INC_VAR_B,
-    INC_VAR_UB,
-    INC_VAR_W,
-    INC_VAR_UW,
-    INC_VAR_F,
-    DEC_VAR_B,
-    DEC_VAR_UB,
-    DEC_VAR_W,
-    DEC_VAR_UW,
-    DEC_VAR_F,
-    INC_MEMORY,             // increment direct address
-    DEC_MEMORY,             // decrement direct address
-    POP_INC_MEMORY,         // increment address from stack
-    POP_DEC_MEMORY,         // decrement address from address
-
-    // comparisons
-    LESS_B,
-    LESS_UB,
-    LESS_W,
-    LESS_UW,
-    LESS_F,
-    GREATER_B,
-    GREATER_UB,
-    GREATER_W,
-    GREATER_UW,
-    GREATER_F,
-    LESSEQ_B,
-    LESSEQ_UB,
-    LESSEQ_W,
-    LESSEQ_UW,
-    LESSEQ_F,
-    GREATEREQ_B,
-    GREATEREQ_UB,
-    GREATEREQ_W,
-    GREATEREQ_UW,
-    GREATEREQ_F,
-    EQUAL_BYTE,
-    EQUAL_WORD,
-    EQUAL_F,
-    NOTEQUAL_BYTE,
-    NOTEQUAL_WORD,
-    NOTEQUAL_F,
-    CMP_B,          // sets processor status flags based on comparison, instead of pushing a result value
-    CMP_UB,         // sets processor status flags based on comparison, instead of pushing a result value
-    CMP_W,          // sets processor status flags based on comparison, instead of pushing a result value
-    CMP_UW,         // sets processor status flags based on comparison, instead of pushing a result value
-
-    // array access and simple manipulations
-    READ_INDEXED_VAR_BYTE,
-    READ_INDEXED_VAR_WORD,
-    READ_INDEXED_VAR_FLOAT,
-    WRITE_INDEXED_VAR_BYTE,
-    WRITE_INDEXED_VAR_WORD,
-    WRITE_INDEXED_VAR_FLOAT,
-    INC_INDEXED_VAR_B,
-    INC_INDEXED_VAR_UB,
-    INC_INDEXED_VAR_W,
-    INC_INDEXED_VAR_UW,
-    INC_INDEXED_VAR_FLOAT,
-    DEC_INDEXED_VAR_B,
-    DEC_INDEXED_VAR_UB,
-    DEC_INDEXED_VAR_W,
-    DEC_INDEXED_VAR_UW,
-    DEC_INDEXED_VAR_FLOAT,
-
-    // branching, without consuming a value from the stack
-    JUMP,
-    BCS,       // branch if carry set
-    BCC,       // branch if carry clear
-    BZ,        // branch if zero flag
-    BNZ,       // branch if not zero flag
-    BNEG,      // branch if negative flag
-    BPOS,      // branch if not negative flag
-    BVS,       // branch if overflow flag
-    BVC,       // branch if not overflow flag
-    // branching, based on value on the stack (which is consumed)
-    JZ,         // branch if value is zero (byte)
-    JNZ,        // branch if value is not zero (byte)
-    JZW,         // branch if value is zero (word)
-    JNZW,        // branch if value is not zero (word)
-
-    // subroutines
-    CALL,
-    RETURN,
-    SYSCALL,
-    START_PROCDEF,
-    END_PROCDEF,
-
-    // misc
-    SEC,        // set carry status flag  NOTE: is mostly fake, carry flag is not affected by any numeric operations
-    CLC,        // clear carry status flag  NOTE: is mostly fake, carry flag is not affected by any numeric operations
-    SEI,        // set irq-disable status flag
-    CLI,        // clear irq-disable status flag
-    CARRY_TO_A, // load var/register A with carry status bit
-    RSAVE,      // save all internal registers and status flags
-    RSAVEX,     // save just X (the evaluation stack pointer)
-    RRESTORE,   // restore all internal registers and status flags
-    RRESTOREX,  // restore just X (the evaluation stack pointer)
-
-    NOP,        // do nothing
-    BREAKPOINT, // breakpoint
-    TERMINATE,  // end the program
-    LINE,       // track source file line number
-    INLINE_ASSEMBLY,        // container to hold inline raw assembly code
-    INCLUDE_FILE            // directive to include a file at this position in the memory of the program
-}
-
-val opcodesWithVarArgument = setOf(
-        Opcode.INC_VAR_B, Opcode.INC_VAR_W, Opcode.DEC_VAR_B, Opcode.DEC_VAR_W,
-        Opcode.INC_VAR_UB, Opcode.INC_VAR_UW, Opcode.DEC_VAR_UB, Opcode.DEC_VAR_UW,
-        Opcode.SHR_VAR_SBYTE, Opcode.SHR_VAR_UBYTE, Opcode.SHR_VAR_SWORD, Opcode.SHR_VAR_UWORD,
-        Opcode.SHL_VAR_BYTE, Opcode.SHL_VAR_WORD,
-        Opcode.ROL_VAR_BYTE, Opcode.ROL_VAR_WORD, Opcode.ROR_VAR_BYTE, Opcode.ROR_VAR_WORD,
-        Opcode.ROL2_VAR_BYTE, Opcode.ROL2_VAR_WORD, Opcode.ROR2_VAR_BYTE, Opcode.ROR2_VAR_WORD,
-        Opcode.POP_VAR_BYTE, Opcode.POP_VAR_WORD, Opcode.POP_VAR_FLOAT,
-        Opcode.PUSH_VAR_BYTE, Opcode.PUSH_VAR_WORD, Opcode.PUSH_VAR_FLOAT, Opcode.PUSH_ADDR_HEAPVAR,
-        Opcode.READ_INDEXED_VAR_BYTE, Opcode.READ_INDEXED_VAR_WORD, Opcode.READ_INDEXED_VAR_FLOAT,
-        Opcode.WRITE_INDEXED_VAR_BYTE, Opcode.WRITE_INDEXED_VAR_WORD, Opcode.WRITE_INDEXED_VAR_FLOAT,
-        Opcode.INC_INDEXED_VAR_UB, Opcode.INC_INDEXED_VAR_B, Opcode.INC_INDEXED_VAR_UW,
-        Opcode.INC_INDEXED_VAR_W, Opcode.INC_INDEXED_VAR_FLOAT,
-        Opcode.DEC_INDEXED_VAR_UB, Opcode.DEC_INDEXED_VAR_B, Opcode.DEC_INDEXED_VAR_UW,
-        Opcode.DEC_INDEXED_VAR_W, Opcode.DEC_INDEXED_VAR_FLOAT
-)
-
-val branchOpcodes = setOf(
-        Opcode.BCS, Opcode.BCC, Opcode.BZ, Opcode.BNZ,
-        Opcode.BNEG, Opcode.BPOS, Opcode.BVS, Opcode.BVC
-)

compiler/src/prog8/compiler/target/CompilationTarget.kt

@@ -0,0 +1,16 @@
+package prog8.compiler.target
+
+import prog8.ast.Program
+import prog8.compiler.CompilationOptions
+import prog8.compiler.Zeropage
+import java.nio.file.Path
+
+internal interface CompilationTarget {
+    companion object {
+        lateinit var name: String
+        lateinit var machine: IMachineDefinition
+        lateinit var encodeString: (str: String) -> List<Short>
+        lateinit var decodeString: (bytes: List<Short>) -> String
+        lateinit var asmGenerator: (Program, Zeropage, CompilationOptions, Path) -> IAssemblyGenerator
+    }
+}

compiler/src/prog8/compiler/target/IAssemblyGenerator.kt

@@ -0,0 +1,12 @@
+package prog8.compiler.target
+
+import prog8.compiler.CompilationOptions
+
+internal interface IAssemblyGenerator {
+    fun compileToAssembly(optimize: Boolean): IAssemblyProgram
+}
+
+internal interface IAssemblyProgram {
+    val name: String
+    fun assemble(options: CompilationOptions)
+}

compiler/src/prog8/compiler/target/IMachineDefinition.kt

@@ -0,0 +1,15 @@
+package prog8.compiler.target
+
+import prog8.compiler.CompilationOptions
+import prog8.compiler.Zeropage
+
+
+interface IMachineDefinition {
+    val FLOAT_MAX_NEGATIVE: Double
+    val FLOAT_MAX_POSITIVE: Double
+    val FLOAT_MEM_SIZE: Int
+
+    val opcodeNames: Set<String>
+
+    fun getZeropage(compilerOptions: CompilationOptions): Zeropage
+}

compiler/src/prog8/compiler/target/c64/AssemblyProgram.kt

@@ -2,31 +2,35 @@ package prog8.compiler.target.c64
 
 import prog8.compiler.CompilationOptions
 import prog8.compiler.OutputType
-import java.io.File
+import prog8.compiler.target.IAssemblyProgram
+import java.nio.file.Path
 import kotlin.system.exitProcess
 
-class AssemblyProgram(val name: String) {
-    private val assemblyFile = "$name.asm"
-    private val viceMonListFile = "$name.vice-mon-list"
+class AssemblyProgram(override val name: String, outputDir: Path): IAssemblyProgram {
+    private val assemblyFile = outputDir.resolve("$name.asm")
+    private val prgFile = outputDir.resolve("$name.prg")
+    private val binFile = outputDir.resolve("$name.bin")
+    private val viceMonListFile = outputDir.resolve("$name.vice-mon-list")
 
-    fun assemble(options: CompilationOptions) {
+    override fun assemble(options: CompilationOptions) {
         // add "-Wlong-branch"  to see warnings about conversion of branch instructions to jumps
-        val command = mutableListOf("64tass", "--ascii", "--case-sensitive", "--long-branch", "-Wall", "-Wno-strict-bool",
-                "-Werror", "-Wno-error=long-branch", "--dump-labels", "--vice-labels", "-l", viceMonListFile, "--no-monitor")
+        val command = mutableListOf("64tass", "--ascii", "--case-sensitive", "--long-branch",
+                "-Wall", "-Wno-strict-bool", "-Wno-shadow", "-Werror", "-Wno-error=long-branch",
+                "--dump-labels", "--vice-labels", "-l", viceMonListFile.toString(), "--no-monitor")
 
         val outFile = when(options.output) {
             OutputType.PRG -> {
                 command.add("--cbm-prg")
                 println("\nCreating C-64 prg.")
-                "$name.prg"
+                prgFile
             }
             OutputType.RAW -> {
                 command.add("--nostart")
                 println("\nCreating raw binary.")
-                "$name.bin"
+                binFile
             }
         }
-        command.addAll(listOf("--output", outFile, assemblyFile))
+        command.addAll(listOf("--output", outFile.toString(), assemblyFile.toString()))
 
         val proc = ProcessBuilder(command).inheritIO().start()
         val result = proc.waitFor()
@@ -41,8 +45,8 @@ class AssemblyProgram(val name: String) {
     private fun generateBreakpointList() {
         // builds list of breakpoints, appends to monitor list file
         val breakpoints = mutableListOf<String>()
-        val pattern = Regex("""al (\w+) \S+_prog8_breakpoint_\d+.?""")      // gather breakpoints by the source label that's generated for them
-        for(line in File(viceMonListFile).readLines()) {
+        val pattern = Regex("""al (\w+) \S+_prog8_breakpoint_\d+.?""")      // gather breakpoints by the source label that"s generated for them
+        for(line in viceMonListFile.toFile().readLines()) {
             val match = pattern.matchEntire(line)
             if(match!=null)
             breakpoints.add("break \$" + match.groupValues[1])
@@ -51,6 +55,6 @@ class AssemblyProgram(val name: String) {
         breakpoints.add(0, "; vice monitor breakpoint list now follows")
         breakpoints.add(1, "; $num breakpoints have been defined")
         breakpoints.add(2, "del")
-        File(viceMonListFile).appendText(breakpoints.joinToString("\n")+"\n")
+        viceMonListFile.toFile().appendText(breakpoints.joinToString("\n")+"\n")
     }
 }

compiler/src/prog8/compiler/target/c64/C64MachineDefinition.kt

@@ -0,0 +1,266 @@
+package prog8.compiler.target.c64
+
+import prog8.compiler.CompilationOptions
+import prog8.compiler.CompilerException
+import prog8.compiler.Zeropage
+import prog8.compiler.ZeropageType
+import prog8.compiler.target.IMachineDefinition
+import java.awt.Color
+import java.awt.image.BufferedImage
+import javax.imageio.ImageIO
+import kotlin.math.absoluteValue
+import kotlin.math.pow
+
+object C64MachineDefinition: IMachineDefinition {
+
+    // 5-byte cbm MFLPT format limitations:
+    override val FLOAT_MAX_POSITIVE = 1.7014118345e+38         // bytes: 255,127,255,255,255
+    override val FLOAT_MAX_NEGATIVE = -1.7014118345e+38        // bytes: 255,255,255,255,255
+    override val FLOAT_MEM_SIZE = 5
+    const val BASIC_LOAD_ADDRESS = 0x0801
+    const val RAW_LOAD_ADDRESS = 0xc000
+
+    // the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
+    // and some heavily used string constants derived from the two values above
+    const val ESTACK_LO_VALUE       = 0xce00        //  $ce00-$ceff inclusive
+    const val ESTACK_HI_VALUE       = 0xcf00        //  $cf00-$cfff inclusive
+    const val ESTACK_LO_HEX         = "\$ce00"
+    const val ESTACK_LO_PLUS1_HEX   = "\$ce01"
+    const val ESTACK_LO_PLUS2_HEX   = "\$ce02"
+    const val ESTACK_HI_HEX         = "\$cf00"
+    const val ESTACK_HI_PLUS1_HEX   = "\$cf01"
+    const val ESTACK_HI_PLUS2_HEX   = "\$cf02"
+
+    override fun getZeropage(compilerOptions: CompilationOptions) = C64Zeropage(compilerOptions)
+
+    // 6502 opcodes (including aliases and illegal opcodes), these cannot be used as variable or label names
+    override val opcodeNames = setOf("adc", "ahx", "alr", "anc", "and", "ane", "arr", "asl", "asr", "axs", "bcc", "bcs",
+            "beq", "bge", "bit", "blt", "bmi", "bne", "bpl", "brk", "bvc", "bvs", "clc",
+            "cld", "cli", "clv", "cmp", "cpx", "cpy", "dcm", "dcp", "dec", "dex", "dey",
+            "eor", "gcc", "gcs", "geq", "gge", "glt", "gmi", "gne", "gpl", "gvc", "gvs",
+            "inc", "ins", "inx", "iny", "isb", "isc", "jam", "jmp", "jsr", "lae", "las",
+            "lax", "lda", "lds", "ldx", "ldy", "lsr", "lxa", "nop", "ora", "pha", "php",
+            "pla", "plp", "rla", "rol", "ror", "rra", "rti", "rts", "sax", "sbc", "sbx",
+            "sec", "sed", "sei", "sha", "shl", "shr", "shs", "shx", "shy", "slo", "sre",
+            "sta", "stx", "sty", "tas", "tax", "tay", "tsx", "txa", "txs", "tya", "xaa")
+
+
+    class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
+
+        companion object {
+            const val SCRATCH_B1 = 0x02
+            const val SCRATCH_REG = 0x03    // temp storage for a register
+            const val SCRATCH_REG_X = 0xfa    // temp storage for register X (the evaluation stack pointer)
+            const val SCRATCH_W1 = 0xfb     // $fb+$fc
+            const val SCRATCH_W2 = 0xfd     // $fd+$fe
+        }
+
+        override val exitProgramStrategy: ExitProgramStrategy = when (options.zeropage) {
+            ZeropageType.BASICSAFE, ZeropageType.DONTUSE -> ExitProgramStrategy.CLEAN_EXIT
+            ZeropageType.FLOATSAFE, ZeropageType.KERNALSAFE, ZeropageType.FULL -> ExitProgramStrategy.SYSTEM_RESET
+        }
+
+
+        init {
+            if (options.floats && options.zeropage !in setOf(ZeropageType.FLOATSAFE, ZeropageType.BASICSAFE, ZeropageType.DONTUSE ))
+                throw CompilerException("when floats are enabled, zero page type should be 'floatsafe' or 'basicsafe' or 'dontuse'")
+
+            if (options.zeropage == ZeropageType.FULL) {
+                free.addAll(0x04..0xf9)
+                free.add(0xff)
+                free.removeAll(listOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_REG_X, SCRATCH_W1, SCRATCH_W1 + 1, SCRATCH_W2, SCRATCH_W2 + 1))
+                free.removeAll(listOf(0xa0, 0xa1, 0xa2, 0x91, 0xc0, 0xc5, 0xcb, 0xf5, 0xf6))        // these are updated by IRQ
+            } else {
+                if (options.zeropage == ZeropageType.KERNALSAFE || options.zeropage == ZeropageType.FLOATSAFE) {
+                    free.addAll(listOf(0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
+                            0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21,
+                            0x22, 0x23, 0x24, 0x25,
+                            0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46,
+                            0x47, 0x48, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x51, 0x52, 0x53,
+                            0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
+                            0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+                            0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72,
+                            0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c,
+                            0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a,
+                            0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0xff
+                            // 0x90-0xfa is 'kernel work storage area'
+                    ))
+                }
+
+                if (options.zeropage == ZeropageType.FLOATSAFE) {
+                    // remove the zero page locations used for floating point operations from the free list
+                    free.removeAll(listOf(
+                            0x12, 0x26, 0x27, 0x28, 0x29, 0x2a,
+                            0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
+                            0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+                            0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72,
+                            0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0xf
+                    ))
+                }
+
+                if(options.zeropage!=ZeropageType.DONTUSE) {
+                    // add the other free Zp addresses,
+                    // these are valid for the C-64 (when no RS232 I/O is performed) but to keep BASIC running fully:
+                    free.addAll(listOf(0x04, 0x05, 0x06, 0x0a, 0x0e,
+                            0x94, 0x95, 0xa7, 0xa8, 0xa9, 0xaa,
+                            0xb5, 0xb6, 0xf7, 0xf8, 0xf9))
+                } else {
+                    // don't use the zeropage at all
+                    free.clear()
+                }
+            }
+            assert(SCRATCH_B1 !in free)
+            assert(SCRATCH_REG !in free)
+            assert(SCRATCH_REG_X !in free)
+            assert(SCRATCH_W1 !in free)
+            assert(SCRATCH_W2 !in free)
+
+            for (reserved in options.zpReserved)
+                reserve(reserved)
+        }
+    }
+
+
+    data class Mflpt5(val b0: Short, val b1: Short, val b2: Short, val b3: Short, val b4: Short) {
+
+        companion object {
+            val zero = Mflpt5(0, 0, 0, 0, 0)
+            fun fromNumber(num: Number): Mflpt5 {
+                // see https://en.wikipedia.org/wiki/Microsoft_Binary_Format
+                // and https://sourceforge.net/p/acme-crossass/code-0/62/tree/trunk/ACME_Lib/cbm/mflpt.a
+                // and https://en.wikipedia.org/wiki/IEEE_754-1985
+
+                val flt = num.toDouble()
+                if (flt < FLOAT_MAX_NEGATIVE || flt > FLOAT_MAX_POSITIVE)
+                    throw CompilerException("floating point number out of 5-byte mflpt range: $this")
+                if (flt == 0.0)
+                    return zero
+
+                val sign = if (flt < 0.0) 0x80L else 0x00L
+                var exponent = 128 + 32    // 128 is cbm's bias, 32 is this algo's bias
+                var mantissa = flt.absoluteValue
+
+                // if mantissa is too large, shift right and adjust exponent
+                while (mantissa >= 0x100000000) {
+                    mantissa /= 2.0
+                    exponent++
+                }
+                // if mantissa is too small, shift left and adjust exponent
+                while (mantissa < 0x80000000) {
+                    mantissa *= 2.0
+                    exponent--
+                }
+
+                return when {
+                    exponent < 0 -> zero  // underflow, use zero instead
+                    exponent > 255 -> throw CompilerException("floating point overflow: $this")
+                    exponent == 0 -> zero
+                    else -> {
+                        val mantLong = mantissa.toLong()
+                        Mflpt5(
+                                exponent.toShort(),
+                                (mantLong.and(0x7f000000L) ushr 24).or(sign).toShort(),
+                                (mantLong.and(0x00ff0000L) ushr 16).toShort(),
+                                (mantLong.and(0x0000ff00L) ushr 8).toShort(),
+                                (mantLong.and(0x000000ffL)).toShort())
+                    }
+                }
+            }
+        }
+
+        fun toDouble(): Double {
+            if (this == zero) return 0.0
+            val exp = b0 - 128
+            val sign = (b1.toInt() and 0x80) > 0
+            val number = 0x80000000L.or(b1.toLong() shl 24).or(b2.toLong() shl 16).or(b3.toLong() shl 8).or(b4.toLong())
+            val result = number.toDouble() * (2.0).pow(exp) / 0x100000000
+            return if (sign) -result else result
+        }
+    }
+
+    object Charset {
+        private val normalImg = ImageIO.read(javaClass.getResource("/charset/c64/charset-normal.png"))
+        private val shiftedImg = ImageIO.read(javaClass.getResource("/charset/c64/charset-shifted.png"))
+
+        private fun scanChars(img: BufferedImage): Array<BufferedImage> {
+
+            val transparent = BufferedImage(img.width, img.height, BufferedImage.TYPE_INT_ARGB)
+            transparent.createGraphics().drawImage(img, 0, 0, null)
+
+            val black = Color(0, 0, 0).rgb
+            val nopixel = Color(0, 0, 0, 0).rgb
+            for (y in 0 until transparent.height) {
+                for (x in 0 until transparent.width) {
+                    val col = transparent.getRGB(x, y)
+                    if (col == black)
+                        transparent.setRGB(x, y, nopixel)
+                }
+            }
+
+            val numColumns = transparent.width / 8
+            val charImages = (0..255).map {
+                val charX = it % numColumns
+                val charY = it / numColumns
+                transparent.getSubimage(charX * 8, charY * 8, 8, 8)
+            }
+            return charImages.toTypedArray()
+        }
+
+        val normalChars = scanChars(normalImg)
+        val shiftedChars = scanChars(shiftedImg)
+
+        private val coloredNormalChars = mutableMapOf<Short, Array<BufferedImage>>()
+
+        fun getColoredChar(screenCode: Short, color: Short): BufferedImage {
+            val colorIdx = (color % colorPalette.size).toShort()
+            val chars = coloredNormalChars[colorIdx]
+            if (chars != null)
+                return chars[screenCode.toInt()]
+
+            val coloredChars = mutableListOf<BufferedImage>()
+            val transparent = Color(0, 0, 0, 0).rgb
+            val rgb = colorPalette[colorIdx.toInt()].rgb
+            for (c in normalChars) {
+                val colored = c.copy()
+                for (y in 0 until colored.height)
+                    for (x in 0 until colored.width) {
+                        if (colored.getRGB(x, y) != transparent) {
+                            colored.setRGB(x, y, rgb)
+                        }
+                    }
+                coloredChars.add(colored)
+            }
+            coloredNormalChars[colorIdx] = coloredChars.toTypedArray()
+            return coloredNormalChars.getValue(colorIdx)[screenCode.toInt()]
+        }
+
+    }
+
+    private fun BufferedImage.copy(): BufferedImage {
+        val bcopy = BufferedImage(this.width, this.height, this.type)
+        val g = bcopy.graphics
+        g.drawImage(this, 0, 0, null)
+        g.dispose()
+        return bcopy
+    }
+
+    val colorPalette = listOf(         // this is Pepto's Commodore-64 palette  http://www.pepto.de/projects/colorvic/
+            Color(0x000000),  // 0 = black
+            Color(0xFFFFFF),  // 1 = white
+            Color(0x813338),  // 2 = red
+            Color(0x75cec8),  // 3 = cyan
+            Color(0x8e3c97),  // 4 = purple
+            Color(0x56ac4d),  // 5 = green
+            Color(0x2e2c9b),  // 6 = blue
+            Color(0xedf171),  // 7 = yellow
+            Color(0x8e5029),  // 8 = orange
+            Color(0x553800),  // 9 = brown
+            Color(0xc46c71),  // 10 = light red
+            Color(0x4a4a4a),  // 11 = dark grey
+            Color(0x7b7b7b),  // 12 = medium grey
+            Color(0xa9ff9f),  // 13 = light green
+            Color(0x706deb),  // 14 = light blue
+            Color(0xb2b2b2)   // 15 = light grey
+    )
+
+}

compiler/src/prog8/compiler/target/c64/Commodore64.kt

@@ -1,242 +0,0 @@
-package prog8.compiler.target.c64
-
-import prog8.compiler.CompilationOptions
-import prog8.compiler.CompilerException
-import prog8.compiler.Zeropage
-import prog8.compiler.ZeropageType
-import java.awt.Color
-import java.awt.image.BufferedImage
-import javax.imageio.ImageIO
-import kotlin.math.absoluteValue
-import kotlin.math.pow
-
-
-// 5-byte cbm MFLPT format limitations:
-const val FLOAT_MAX_POSITIVE = 1.7014118345e+38         // bytes: 255,127,255,255,255
-const val FLOAT_MAX_NEGATIVE = -1.7014118345e+38        // bytes: 255,255,255,255,255
-
-const val BASIC_LOAD_ADDRESS = 0x0801
-const val RAW_LOAD_ADDRESS = 0xc000
-
-// the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
-const val ESTACK_LO = 0xce00        //  $ce00-$ceff inclusive
-const val ESTACK_HI = 0xcf00        //  $cf00-$cfff inclusive
-
-
-class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
-
-    companion object {
-        const val SCRATCH_B1 = 0x02
-        const val SCRATCH_REG = 0x03    // temp storage for a register
-        const val SCRATCH_REG_X = 0xfa    // temp storage for register X (the evaluation stack pointer)
-        const val SCRATCH_W1 = 0xfb     // $fb+$fc
-        const val SCRATCH_W2 = 0xfd     // $fd+$fe
-    }
-
-    override val exitProgramStrategy: ExitProgramStrategy = when(options.zeropage) {
-        ZeropageType.BASICSAFE -> ExitProgramStrategy.CLEAN_EXIT
-        ZeropageType.FLOATSAFE, ZeropageType.KERNALSAFE, ZeropageType.FULL -> ExitProgramStrategy.SYSTEM_RESET
-    }
-
-
-    init {
-        if(options.floats && options.zeropage!=ZeropageType.FLOATSAFE && options.zeropage!=ZeropageType.BASICSAFE)
-            throw CompilerException("when floats are enabled, zero page type should be 'floatsafe' or 'basicsafe'")
-
-        if(options.zeropage == ZeropageType.FULL) {
-            free.addAll(0x04 .. 0xf9)
-            free.add(0xff)
-            free.removeAll(listOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_REG_X, SCRATCH_W1, SCRATCH_W1+1, SCRATCH_W2, SCRATCH_W2+1))
-            free.removeAll(listOf(0xa0, 0xa1, 0xa2, 0x91, 0xc0, 0xc5, 0xcb, 0xf5, 0xf6))        // these are updated by IRQ
-        } else {
-            if(options.zeropage == ZeropageType.KERNALSAFE || options.zeropage == ZeropageType.FLOATSAFE) {
-                free.addAll(listOf(0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
-                        0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21,
-                        0x22, 0x23, 0x24, 0x25,
-                        0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46,
-                        0x47, 0x48, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x51, 0x52, 0x53,
-                        0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
-                        0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
-                        0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72,
-                        0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c,
-                        0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a,
-                        0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0xff
-                        // 0x90-0xfa is 'kernel work storage area'
-                ))
-            }
-
-            if(options.zeropage == ZeropageType.FLOATSAFE) {
-                // remove the zero page locations used for floating point operations from the free list
-                free.removeAll(listOf(
-                        0x12, 0x26, 0x27, 0x28, 0x29, 0x2a,
-                        0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
-                        0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
-                        0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72,
-                        0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0xf
-                ))
-            }
-
-            // add the other free Zp addresses,
-            // these are valid for the C-64 (when no RS232 I/O is performed) but to keep BASIC running fully:
-            free.addAll(listOf(0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0d, 0x0e,
-                    0x94, 0x95, 0xa7, 0xa8, 0xa9, 0xaa,
-                    0xb5, 0xb6, 0xf7, 0xf8, 0xf9))
-        }
-        assert(SCRATCH_B1 !in free)
-        assert(SCRATCH_REG !in free)
-        assert(SCRATCH_REG_X !in free)
-        assert(SCRATCH_W1 !in free)
-        assert(SCRATCH_W2 !in free)
-
-        for(reserved in options.zpReserved)
-            reserve(reserved)
-    }
-}
-
-
-data class Mflpt5(val b0: Short, val b1: Short, val b2: Short, val b3: Short, val b4: Short) {
-
-    companion object {
-        const val MemorySize = 5
-
-        val zero = Mflpt5(0, 0,0,0,0)
-        fun fromNumber(num: Number): Mflpt5 {
-            // see https://en.wikipedia.org/wiki/Microsoft_Binary_Format
-            // and https://sourceforge.net/p/acme-crossass/code-0/62/tree/trunk/ACME_Lib/cbm/mflpt.a
-            // and https://en.wikipedia.org/wiki/IEEE_754-1985
-
-            val flt = num.toDouble()
-            if(flt < FLOAT_MAX_NEGATIVE || flt > FLOAT_MAX_POSITIVE)
-                throw CompilerException("floating point number out of 5-byte mflpt range: $this")
-            if(flt==0.0)
-                return zero
-
-            val sign = if(flt<0.0) 0x80L else 0x00L
-            var exponent = 128 + 32	// 128 is cbm's bias, 32 is this algo's bias
-            var mantissa = flt.absoluteValue
-
-            // if mantissa is too large, shift right and adjust exponent
-            while(mantissa >= 0x100000000) {
-                mantissa /= 2.0
-                exponent ++
-            }
-            // if mantissa is too small, shift left and adjust exponent
-            while(mantissa < 0x80000000) {
-                mantissa *= 2.0
-                exponent --
-            }
-
-            return when {
-                exponent<0 -> zero  // underflow, use zero instead
-                exponent>255 -> throw CompilerException("floating point overflow: $this")
-                exponent==0 -> zero
-                else -> {
-                    val mantLong = mantissa.toLong()
-                    Mflpt5(
-                            exponent.toShort(),
-                            (mantLong.and(0x7f000000L) ushr 24).or(sign).toShort(),
-                            (mantLong.and(0x00ff0000L) ushr 16).toShort(),
-                            (mantLong.and(0x0000ff00L) ushr 8).toShort(),
-                            (mantLong.and(0x000000ffL)).toShort())
-                }
-            }
-        }
-    }
-
-    fun toDouble(): Double {
-        if(this == zero) return 0.0
-        val exp = b0 - 128
-        val sign = (b1.toInt() and 0x80) > 0
-        val number = 0x80000000L.or(b1.toLong() shl 24).or(b2.toLong() shl 16).or(b3.toLong() shl 8).or(b4.toLong())
-        val result = number.toDouble() * (2.0).pow(exp) / 0x100000000
-        return if(sign) -result else result
-    }
-}
-
-object Charset {
-    private val normalImg = ImageIO.read(javaClass.getResource("/charset/c64/charset-normal.png"))
-    private val shiftedImg = ImageIO.read(javaClass.getResource("/charset/c64/charset-shifted.png"))
-
-    private fun scanChars(img: BufferedImage): Array<BufferedImage> {
-
-        val transparent = BufferedImage(img.width, img.height, BufferedImage.TYPE_INT_ARGB)
-        transparent.createGraphics().drawImage(img, 0, 0, null)
-
-        val black = Color(0,0,0).rgb
-        val nopixel = Color(0,0,0,0).rgb
-        for(y in 0 until transparent.height) {
-            for(x in 0 until transparent.width) {
-                val col = transparent.getRGB(x, y)
-                if(col==black)
-                    transparent.setRGB(x, y, nopixel)
-            }
-        }
-
-        val numColumns = transparent.width / 8
-        val charImages = (0..255).map {
-            val charX = it % numColumns
-            val charY = it/ numColumns
-            transparent.getSubimage(charX*8, charY*8, 8, 8)
-        }
-        return charImages.toTypedArray()
-    }
-
-    val normalChars = scanChars(normalImg)
-    val shiftedChars = scanChars(shiftedImg)
-
-    private val coloredNormalChars = mutableMapOf<Short, Array<BufferedImage>>()
-
-    fun getColoredChar(screenCode: Short, color: Short): BufferedImage {
-        val colorIdx = (color % Colors.palette.size).toShort()
-        val chars = coloredNormalChars[colorIdx]
-        if(chars!=null)
-            return chars[screenCode.toInt()]
-
-        val coloredChars = mutableListOf<BufferedImage>()
-        val transparent = Color(0,0,0,0).rgb
-        val rgb = Colors.palette[colorIdx.toInt()].rgb
-        for(c in normalChars) {
-            val colored = c.copy()
-            for(y in 0 until colored.height)
-                for(x in 0 until colored.width) {
-                    if(colored.getRGB(x, y)!=transparent) {
-                        colored.setRGB(x, y, rgb)
-                    }
-                }
-            coloredChars.add(colored)
-        }
-        coloredNormalChars[colorIdx] = coloredChars.toTypedArray()
-        return coloredNormalChars.getValue(colorIdx)[screenCode.toInt()]
-    }
-
-}
-
-private fun BufferedImage.copy(): BufferedImage {
-    val bcopy = BufferedImage(this.width, this.height, this.type)
-    val g = bcopy.graphics
-    g.drawImage(this, 0, 0, null)
-    g.dispose()
-    return bcopy
-}
-
-
-object Colors {
-    val palette = listOf(         // this is Pepto's Commodore-64 palette  http://www.pepto.de/projects/colorvic/
-            Color(0x000000),  // 0 = black
-            Color(0xFFFFFF),  // 1 = white
-            Color(0x813338),  // 2 = red
-            Color(0x75cec8),  // 3 = cyan
-            Color(0x8e3c97),  // 4 = purple
-            Color(0x56ac4d),  // 5 = green
-            Color(0x2e2c9b),  // 6 = blue
-            Color(0xedf171),  // 7 = yellow
-            Color(0x8e5029),  // 8 = orange
-            Color(0x553800),  // 9 = brown
-            Color(0xc46c71),  // 10 = light red
-            Color(0x4a4a4a),  // 11 = dark grey
-            Color(0x7b7b7b),  // 12 = medium grey
-            Color(0xa9ff9f),  // 13 = light green
-            Color(0x706deb),  // 14 = light blue
-            Color(0xb2b2b2)   // 15 = light grey
-    )
-}

compiler/src/prog8/compiler/target/c64/codegen/AsmGen.kt

@@ -0,0 +1,871 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.antlr.escape
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.statements.*
+import prog8.compiler.*
+import prog8.compiler.target.IAssemblyGenerator
+import prog8.compiler.target.IAssemblyProgram
+import prog8.compiler.target.c64.AssemblyProgram
+import prog8.compiler.target.c64.C64MachineDefinition
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_HEX
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_HI_HEX
+import prog8.compiler.target.c64.Petscii
+import prog8.functions.BuiltinFunctions
+import prog8.functions.FunctionSignature
+import java.math.RoundingMode
+import java.nio.file.Path
+import java.time.LocalDate
+import java.time.LocalDateTime
+import java.util.ArrayDeque
+import kotlin.math.absoluteValue
+
+
+internal class AsmGen(private val program: Program,
+             private val zeropage: Zeropage,
+             private val options: CompilationOptions,
+             private val outputDir: Path): IAssemblyGenerator {
+
+    private val assemblyLines = mutableListOf<String>()
+    private val globalFloatConsts = mutableMapOf<Double, String>()     // all float values in the entire program (value -> varname)
+    private val allocatedZeropageVariables = mutableMapOf<String, Pair<Int, DataType>>()
+    private val breakpointLabels = mutableListOf<String>()
+    private val builtinFunctionsAsmGen = BuiltinFunctionsAsmGen(program, this)
+    private val forloopsAsmGen = ForLoopsAsmGen(program, this)
+    private val postincrdecrAsmGen = PostIncrDecrAsmGen(program, this)
+    private val functioncallAsmGen = FunctionCallAsmGen(program, this)
+    private val assignmentAsmGen = AssignmentAsmGen(program, this)
+    private val expressionsAsmGen = ExpressionsAsmGen(program, this)
+    internal val loopEndLabels = ArrayDeque<String>()
+    internal val loopContinueLabels = ArrayDeque<String>()
+
+    override fun compileToAssembly(optimize: Boolean): IAssemblyProgram {
+        assemblyLines.clear()
+        loopEndLabels.clear()
+        loopContinueLabels.clear()
+
+        println("Generating assembly code... ")
+
+        header()
+        val allBlocks = program.allBlocks()
+        if(allBlocks.first().name != "main")
+            throw AssemblyError("first block should be 'main'")
+        for(b in program.allBlocks())
+            block2asm(b)
+        footer()
+
+        if(optimize) {
+            var optimizationsDone = 1
+            while (optimizationsDone > 0) {
+                optimizationsDone = optimizeAssembly(assemblyLines)
+            }
+        }
+
+        val outputFile = outputDir.resolve("${program.name}.asm").toFile()
+        outputFile.printWriter().use {
+            for (line in assemblyLines) { it.println(line) }
+        }
+
+        return AssemblyProgram(program.name, outputDir)
+    }
+
+    private fun header() {
+        val ourName = this.javaClass.name
+        out("; 6502 assembly code for '${program.name}'")
+        out("; generated by $ourName on ${LocalDateTime.now().withNano(0)}")
+        out("; assembler syntax is for the 64tasm cross-assembler")
+        out("; output options: output=${options.output} launcher=${options.launcher} zp=${options.zeropage}")
+        out("\n.cpu  '6502'\n.enc  'none'\n")
+
+        program.actualLoadAddress = program.definedLoadAddress
+        if (program.actualLoadAddress == 0)   // fix load address
+            program.actualLoadAddress = if (options.launcher == LauncherType.BASIC)
+                C64MachineDefinition.BASIC_LOAD_ADDRESS else C64MachineDefinition.RAW_LOAD_ADDRESS
+
+        when {
+            options.launcher == LauncherType.BASIC -> {
+                if (program.actualLoadAddress != 0x0801)
+                    throw AssemblyError("BASIC output must have load address $0801")
+                out("; ---- basic program with sys call ----")
+                out("* = ${program.actualLoadAddress.toHex()}")
+                val year = LocalDate.now().year
+                out("  .word  (+), $year")
+                out("  .null  $9e, format(' %d ', _prog8_entrypoint), $3a, $8f, ' prog8 by idj'")
+                out("+\t.word  0")
+                out("_prog8_entrypoint\t; assembly code starts here\n")
+                out("  jsr  prog8_lib.init_system")
+            }
+            options.output == OutputType.PRG -> {
+                out("; ---- program without basic sys call ----")
+                out("* = ${program.actualLoadAddress.toHex()}\n")
+                out("  jsr  prog8_lib.init_system")
+            }
+            options.output == OutputType.RAW -> {
+                out("; ---- raw assembler program ----")
+                out("* = ${program.actualLoadAddress.toHex()}\n")
+            }
+        }
+
+        if (zeropage.exitProgramStrategy != Zeropage.ExitProgramStrategy.CLEAN_EXIT) {
+            // disable shift-commodore charset switching and run/stop key
+            out("  lda  #$80")
+            out("  lda  #$80")
+            out("  sta  657\t; disable charset switching")
+            out("  lda  #239")
+            out("  sta  808\t; disable run/stop key")
+        }
+
+        out("  ldx  #\$ff\t; init estack pointer")
+
+        out("  ; initialize the variables in each block")
+        for (block in program.allBlocks()) {
+            val initVarsSub = block.statements.singleOrNull { it is Subroutine && it.name == initvarsSubName }
+            if(initVarsSub!=null)
+                out("  jsr  ${block.name}.$initvarsSubName")
+        }
+
+        out("  clc")
+        when (zeropage.exitProgramStrategy) {
+            Zeropage.ExitProgramStrategy.CLEAN_EXIT -> {
+                out("  jmp  main.start\t; jump to program entrypoint")
+            }
+            Zeropage.ExitProgramStrategy.SYSTEM_RESET -> {
+                out("  jsr  main.start\t; call program entrypoint")
+                out("  jmp  (c64.RESET_VEC)\t; cold reset")
+            }
+        }
+        out("")
+    }
+
+    private fun footer() {
+        // the global list of all floating point constants for the whole program
+        out("; global float constants")
+        for (flt in globalFloatConsts) {
+            val mflpt5 = C64MachineDefinition.Mflpt5.fromNumber(flt.key)
+            val floatFill = makeFloatFill(mflpt5)
+            val floatvalue = flt.key
+            out("${flt.value}\t.byte  $floatFill  ; float $floatvalue")
+        }
+    }
+
+    private fun block2asm(block: Block) {
+        out("\n\n; ---- block: '${block.name}' ----")
+        out("${block.name}\t" + (if("force_output" in block.options()) ".block\n" else ".proc\n"))
+
+        if(block.address!=null) {
+            out(".cerror * > ${block.address.toHex()}, 'block address overlaps by ', *-${block.address.toHex()},' bytes'")
+            out("* = ${block.address.toHex()}")
+        }
+
+        outputSourceLine(block)
+        zeropagevars2asm(block.statements)
+        memdefs2asm(block.statements)
+        vardecls2asm(block.statements)
+        out("\n; subroutines in this block")
+
+        // first translate regular statements, and then put the subroutines at the end.
+        val (subroutine, stmts) = block.statements.partition { it is Subroutine }
+        stmts.forEach { translate(it) }
+        subroutine.forEach { translateSubroutine(it as Subroutine) }
+
+        out(if("force_output" in block.options()) "\n\t.bend\n" else "\n\t.pend\n")
+    }
+
+    private var generatedLabelSequenceNumber: Int = 0
+
+    internal fun makeLabel(postfix: String): String {
+        generatedLabelSequenceNumber++
+        return "_prog8_label_${generatedLabelSequenceNumber}_$postfix"
+    }
+
+    private fun outputSourceLine(node: Node) {
+        out(" ;\tsrc line: ${node.position.file}:${node.position.line}")
+    }
+
+    internal fun out(str: String, splitlines: Boolean = true) {
+        val fragment = (if(" | " in str) str.replace("|", "\n") else str).trim('\n')
+
+        if (splitlines) {
+            for (line in fragment.split('\n')) {
+                val trimmed = if (line.startsWith(' ')) "\t" + line.trim() else line.trim()
+                // trimmed = trimmed.replace(Regex("^\\+\\s+"), "+\t")  // sanitize local label indentation
+                assemblyLines.add(trimmed)
+            }
+        } else assemblyLines.add(fragment)
+    }
+
+    private fun makeFloatFill(flt: C64MachineDefinition.Mflpt5): String {
+        val b0 = "$" + flt.b0.toString(16).padStart(2, '0')
+        val b1 = "$" + flt.b1.toString(16).padStart(2, '0')
+        val b2 = "$" + flt.b2.toString(16).padStart(2, '0')
+        val b3 = "$" + flt.b3.toString(16).padStart(2, '0')
+        val b4 = "$" + flt.b4.toString(16).padStart(2, '0')
+        return "$b0, $b1, $b2, $b3, $b4"
+    }
+
+    private fun petscii(str: String): List<Short> {
+         val bytes = Petscii.encodePetscii(str, true)
+         return bytes.plus(0)
+    }
+
+    private fun zeropagevars2asm(statements: List<Statement>) {
+        out("; vars allocated on zeropage")
+        val variables = statements.filterIsInstance<VarDecl>().filter { it.type==VarDeclType.VAR }
+        for(variable in variables) {
+            // should NOT allocate subroutine parameters on the zero page
+            val fullName = variable.scopedname
+            val zpVar = allocatedZeropageVariables[fullName]
+            if(zpVar==null) {
+                // This var is not on the ZP yet. Attempt to move it there (if it's not a float, those take up too much space)
+                if(variable.zeropage != ZeropageWish.NOT_IN_ZEROPAGE &&
+                        variable.datatype in zeropage.allowedDatatypes
+                        && variable.datatype != DataType.FLOAT
+                        && options.zeropage != ZeropageType.DONTUSE) {
+                    try {
+                        val address = zeropage.allocate(fullName, variable.datatype, null)
+                        out("${variable.name} = $address\t; auto zp ${variable.datatype}")
+                        // make sure we add the var to the set of zpvars for this block
+                        allocatedZeropageVariables[fullName] = Pair(address, variable.datatype)
+                    } catch (x: ZeropageDepletedError) {
+                        // leave it as it is.
+                    }
+                }
+            }
+        }
+    }
+
+    private fun vardecl2asm(decl: VarDecl) {
+        when (decl.datatype) {
+            DataType.UBYTE -> out("${decl.name}\t.byte  0")
+            DataType.BYTE -> out("${decl.name}\t.char  0")
+            DataType.UWORD -> out("${decl.name}\t.word  0")
+            DataType.WORD -> out("${decl.name}\t.sint  0")
+            DataType.FLOAT -> out("${decl.name}\t.byte  0,0,0,0,0  ; float")
+            DataType.STRUCT -> {}       // is flattened
+            DataType.STR -> {
+                val string = (decl.value as StringLiteralValue).value
+                outputStringvar(decl, petscii(string))
+            }
+            DataType.ARRAY_UB -> {
+                val data = makeArrayFillDataUnsigned(decl)
+                if (data.size <= 16)
+                    out("${decl.name}\t.byte  ${data.joinToString()}")
+                else {
+                    out(decl.name)
+                    for (chunk in data.chunked(16))
+                        out("  .byte  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_B -> {
+                val data = makeArrayFillDataSigned(decl)
+                if (data.size <= 16)
+                    out("${decl.name}\t.char  ${data.joinToString()}")
+                else {
+                    out(decl.name)
+                    for (chunk in data.chunked(16))
+                        out("  .char  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_UW -> {
+                val data = makeArrayFillDataUnsigned(decl)
+                if (data.size <= 16)
+                    out("${decl.name}\t.word  ${data.joinToString()}")
+                else {
+                    out(decl.name)
+                    for (chunk in data.chunked(16))
+                        out("  .word  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_W -> {
+                val data = makeArrayFillDataSigned(decl)
+                if (data.size <= 16)
+                    out("${decl.name}\t.sint  ${data.joinToString()}")
+                else {
+                    out(decl.name)
+                    for (chunk in data.chunked(16))
+                        out("  .sint  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_F -> {
+                val array = (decl.value as ArrayLiteralValue).value
+                val floatFills = array.map {
+                    val number = (it as NumericLiteralValue).number
+                    makeFloatFill(C64MachineDefinition.Mflpt5.fromNumber(number))
+                }
+                out(decl.name)
+                for (f in array.zip(floatFills))
+                    out("  .byte  ${f.second}  ; float ${f.first}")
+            }
+        }
+    }
+
+    private fun memdefs2asm(statements: List<Statement>) {
+        out("\n; memdefs and kernel subroutines")
+        val memvars = statements.filterIsInstance<VarDecl>().filter { it.type==VarDeclType.MEMORY || it.type==VarDeclType.CONST }
+        for(m in memvars) {
+            out("  ${m.name} = ${(m.value as NumericLiteralValue).number.toHex()}")
+        }
+        val asmSubs = statements.filterIsInstance<Subroutine>().filter { it.isAsmSubroutine }
+        for(sub in asmSubs) {
+            if(sub.asmAddress!=null) {
+                if(sub.statements.isNotEmpty())
+                    throw AssemblyError("kernel subroutine cannot have statements")
+                out("  ${sub.name} = ${sub.asmAddress.toHex()}")
+            }
+        }
+    }
+
+    private fun vardecls2asm(statements: List<Statement>) {
+        out("\n; non-zeropage variables")
+        val vars = statements.filterIsInstance<VarDecl>().filter { it.type==VarDeclType.VAR }
+
+        // first output the flattened struct member variables *in order*
+        // after that, the other variables sorted by their datatype
+
+        val (structMembers, normalVars) = vars.partition { it.struct!=null }
+        structMembers.forEach { vardecl2asm(it) }
+
+        // special treatment for string types: merge strings that are identical
+        val encodedstringVars = normalVars
+                .filter {it.datatype == DataType.STR }
+                .map { it to petscii((it.value as StringLiteralValue).value) }
+                .groupBy({it.second}, {it.first})
+        for((encoded, variables) in encodedstringVars) {
+            variables.dropLast(1).forEach { out(it.name) }
+            val lastvar = variables.last()
+            outputStringvar(lastvar, encoded)
+        }
+
+        // non-string variables
+        normalVars.filter{ it.datatype != DataType.STR }.sortedBy { it.datatype }.forEach {
+            if(it.scopedname !in allocatedZeropageVariables)
+                vardecl2asm(it)
+        }
+    }
+
+    private fun outputStringvar(lastvar: VarDecl, encoded: List<Short>) {
+        val string = (lastvar.value as StringLiteralValue).value
+        out("${lastvar.name}\t; ${lastvar.datatype} \"${escape(string).replace("\u0000", "<NULL>")}\"")
+        val outputBytes = encoded.map { "$" + it.toString(16).padStart(2, '0') }
+        for (chunk in outputBytes.chunked(16))
+            out("  .byte  " + chunk.joinToString())
+    }
+
+    private fun makeArrayFillDataUnsigned(decl: VarDecl): List<String> {
+        val array = (decl.value as ArrayLiteralValue).value
+        return when (decl.datatype) {
+            DataType.ARRAY_UB ->
+                // byte array can never contain pointer-to types, so treat values as all integers
+                array.map {
+                    val number = (it as NumericLiteralValue).number.toInt()
+                    "$"+number.toString(16).padStart(2, '0')
+                }
+            DataType.ARRAY_UW -> array.map {
+                if(it is NumericLiteralValue) {
+                    "$" + it.number.toInt().toString(16).padStart(4, '0')
+                } else {
+                    (it as AddressOf).identifier.nameInSource.joinToString(".")
+                }
+            }
+            else -> throw AssemblyError("invalid arraysize type")
+        }
+    }
+
+    private fun makeArrayFillDataSigned(decl: VarDecl): List<String> {
+        val array = (decl.value as ArrayLiteralValue).value
+
+        return when {
+            decl.datatype == DataType.ARRAY_UB ->
+                // byte array can never contain pointer-to types, so treat values as all integers
+                array.map {
+                    val number = (it as NumericLiteralValue).number.toInt()
+                    val hexnum = number.toString(16).padStart(2, '0')
+                    "$$hexnum"
+                }
+            decl.datatype == DataType.ARRAY_B ->
+                // byte array can never contain pointer-to types, so treat values as all integers
+                array.map {
+                    val number = (it as NumericLiteralValue).number.toInt()
+                    val hexnum = number.absoluteValue.toString(16).padStart(2, '0')
+                    if(number>=0)
+                        "$$hexnum"
+                    else
+                        "-$$hexnum"
+                }
+            decl.datatype== DataType.ARRAY_UW -> array.map {
+                val number = (it as NumericLiteralValue).number.toInt()
+                val hexnum = number.toString(16).padStart(4, '0')
+                "$$hexnum"
+            }
+            decl.datatype== DataType.ARRAY_W -> array.map {
+                val number = (it as NumericLiteralValue).number.toInt()
+                val hexnum = number.absoluteValue.toString(16).padStart(4, '0')
+                if(number>=0)
+                    "$$hexnum"
+                else
+                    "-$$hexnum"
+            }
+            else -> throw AssemblyError("invalid arraysize type ${decl.datatype}")
+        }
+    }
+
+    internal fun getFloatConst(number: Double): String {
+        // try to match the ROM float constants to save memory
+        val mflpt5 = C64MachineDefinition.Mflpt5.fromNumber(number)
+        val floatbytes = shortArrayOf(mflpt5.b0, mflpt5.b1, mflpt5.b2, mflpt5.b3, mflpt5.b4)
+        when {
+            floatbytes.contentEquals(shortArrayOf(0x00, 0x00, 0x00, 0x00, 0x00)) -> return "c64flt.FL_ZERO"
+            floatbytes.contentEquals(shortArrayOf(0x82, 0x49, 0x0f, 0xda, 0xa1)) -> return "c64flt.FL_PIVAL"
+            floatbytes.contentEquals(shortArrayOf(0x90, 0x80, 0x00, 0x00, 0x00)) -> return "c64flt.FL_N32768"
+            floatbytes.contentEquals(shortArrayOf(0x81, 0x00, 0x00, 0x00, 0x00)) -> return "c64flt.FL_FONE"
+            floatbytes.contentEquals(shortArrayOf(0x80, 0x35, 0x04, 0xf3, 0x34)) -> return "c64flt.FL_SQRHLF"
+            floatbytes.contentEquals(shortArrayOf(0x81, 0x35, 0x04, 0xf3, 0x34)) -> return "c64flt.FL_SQRTWO"
+            floatbytes.contentEquals(shortArrayOf(0x80, 0x80, 0x00, 0x00, 0x00)) -> return "c64flt.FL_NEGHLF"
+            floatbytes.contentEquals(shortArrayOf(0x80, 0x31, 0x72, 0x17, 0xf8)) -> return "c64flt.FL_LOG2"
+            floatbytes.contentEquals(shortArrayOf(0x84, 0x20, 0x00, 0x00, 0x00)) -> return "c64flt.FL_TENC"
+            floatbytes.contentEquals(shortArrayOf(0x9e, 0x6e, 0x6b, 0x28, 0x00)) -> return "c64flt.FL_NZMIL"
+            floatbytes.contentEquals(shortArrayOf(0x80, 0x00, 0x00, 0x00, 0x00)) -> return "c64flt.FL_FHALF"
+            floatbytes.contentEquals(shortArrayOf(0x81, 0x38, 0xaa, 0x3b, 0x29)) -> return "c64flt.FL_LOGEB2"
+            floatbytes.contentEquals(shortArrayOf(0x81, 0x49, 0x0f, 0xda, 0xa2)) -> return "c64flt.FL_PIHALF"
+            floatbytes.contentEquals(shortArrayOf(0x83, 0x49, 0x0f, 0xda, 0xa2)) -> return "c64flt.FL_TWOPI"
+            floatbytes.contentEquals(shortArrayOf(0x7f, 0x00, 0x00, 0x00, 0x00)) -> return "c64flt.FL_FR4"
+            else -> {
+                // attempt to correct for a few rounding issues
+                when (number.toBigDecimal().setScale(10, RoundingMode.HALF_DOWN).toDouble()) {
+                    3.1415926536 -> return "c64flt.FL_PIVAL"
+                    1.4142135624 -> return "c64flt.FL_SQRTWO"
+                    0.7071067812 -> return "c64flt.FL_SQRHLF"
+                    0.6931471806 -> return "c64flt.FL_LOG2"
+                    else -> {}
+                }
+
+                // no ROM float const for this value, create our own
+                val name = globalFloatConsts[number]
+                if(name!=null)
+                    return name
+                val newName = "prog8_float_const_${globalFloatConsts.size}"
+                globalFloatConsts[number] = newName
+                return newName
+            }
+        }
+    }
+
+    internal fun signExtendAtoMsb(destination: String) =
+            """
+        ora  #$7f
+        bmi  +
+        lda  #0
++       sta  $destination
+        """
+
+    internal fun asmIdentifierName(identifier: IdentifierReference): String {
+        val name = if(identifier.memberOfStruct(program.namespace)!=null) {
+            identifier.targetVarDecl(program.namespace)!!.name
+        } else {
+            identifier.nameInSource.joinToString(".")
+        }
+        return fixNameSymbols(name)
+    }
+
+    internal fun fixNameSymbols(name: String) = name.replace("<", "prog8_").replace(">", "")     // take care of the autogenerated invalid (anon) label names
+
+    private fun branchInstruction(condition: BranchCondition, complement: Boolean) =
+            if(complement) {
+                when (condition) {
+                    BranchCondition.CS -> "bcc"
+                    BranchCondition.CC -> "bcs"
+                    BranchCondition.EQ, BranchCondition.Z -> "beq"
+                    BranchCondition.NE, BranchCondition.NZ -> "bne"
+                    BranchCondition.VS -> "bvc"
+                    BranchCondition.VC -> "bvs"
+                    BranchCondition.MI, BranchCondition.NEG -> "bmi"
+                    BranchCondition.PL, BranchCondition.POS -> "bpl"
+                }
+            } else {
+                when (condition) {
+                    BranchCondition.CS -> "bcs"
+                    BranchCondition.CC -> "bcc"
+                    BranchCondition.EQ, BranchCondition.Z -> "beq"
+                    BranchCondition.NE, BranchCondition.NZ -> "bne"
+                    BranchCondition.VS -> "bvs"
+                    BranchCondition.VC -> "bvc"
+                    BranchCondition.MI, BranchCondition.NEG -> "bmi"
+                    BranchCondition.PL, BranchCondition.POS -> "bpl"
+                }
+            }
+
+    internal fun readAndPushArrayvalueWithIndexA(arrayDt: DataType, variable: IdentifierReference) {
+        val variablename = asmIdentifierName(variable)
+        when (arrayDt) {
+            DataType.STR, DataType.ARRAY_UB, DataType.ARRAY_B ->
+                out("  tay |  lda  $variablename,y |  sta  $ESTACK_LO_HEX,x |  dex")
+            DataType.ARRAY_UW, DataType.ARRAY_W ->
+                out("  asl  a |  tay |  lda  $variablename,y |  sta  $ESTACK_LO_HEX,x |  lda  $variablename+1,y |  sta  $ESTACK_HI_HEX,x | dex")
+            DataType.ARRAY_F ->
+                // index * 5 is done in the subroutine that's called
+                out("""
+                    sta  $ESTACK_LO_HEX,x
+                    dex
+                    lda  #<$variablename
+                    ldy  #>$variablename
+                    jsr  c64flt.push_float_from_indexed_var
+                """)
+            else ->
+                throw AssemblyError("weird array type")
+        }
+    }
+
+    internal fun saveRegister(register: Register) {
+        when(register) {
+            Register.A -> out("  pha")
+            Register.X -> out("  txa | pha")
+            Register.Y -> out("  tya | pha")
+        }
+    }
+
+    internal fun restoreRegister(register: Register) {
+        when(register) {
+            Register.A -> out("  pla")
+            Register.X -> out("  pla | tax")
+            Register.Y -> out("  pla | tay")
+        }
+    }
+
+    private fun translateSubroutine(sub: Subroutine) {
+        out("")
+        outputSourceLine(sub)
+
+        if(sub.isAsmSubroutine) {
+            if(sub.asmAddress!=null)
+                return  // already done at the memvars section
+
+            // asmsub with most likely just an inline asm in it
+            out("${sub.name}\t.proc")
+            sub.statements.forEach{ translate(it) }
+            out("  .pend\n")
+        } else {
+            // regular subroutine
+            out("${sub.name}\t.proc")
+            zeropagevars2asm(sub.statements)
+            memdefs2asm(sub.statements)
+            out("; statements")
+            sub.statements.forEach{ translate(it) }
+            out("; variables")
+            vardecls2asm(sub.statements)
+            out("  .pend\n")
+        }
+    }
+
+    internal fun translate(stmt: Statement) {
+        outputSourceLine(stmt)
+        when(stmt) {
+            is VarDecl, is StructDecl, is NopStatement -> {}
+            is Directive -> translate(stmt)
+            is Return -> translate(stmt)
+            is Subroutine -> translateSubroutine(stmt)
+            is InlineAssembly -> translate(stmt)
+            is FunctionCallStatement -> {
+                val functionName = stmt.target.nameInSource.last()
+                val builtinFunc = BuiltinFunctions[functionName]
+                if(builtinFunc!=null) {
+                    builtinFunctionsAsmGen.translateFunctioncallStatement(stmt, builtinFunc)
+                } else {
+                    functioncallAsmGen.translateFunctionCall(stmt)
+                    // discard any results from the stack:
+                    val sub = stmt.target.targetSubroutine(program.namespace)!!
+                    val returns = sub.returntypes.zip(sub.asmReturnvaluesRegisters)
+                    for((t, reg) in returns) {
+                        if(reg.stack) {
+                            if (t in IntegerDatatypes || t in PassByReferenceDatatypes) out("  inx")
+                            else if (t == DataType.FLOAT) out("  inx |  inx |  inx")
+                        }
+                    }
+                }
+            }
+            is Assignment -> assignmentAsmGen.translate(stmt)
+            is Jump -> translate(stmt)
+            is PostIncrDecr -> postincrdecrAsmGen.translate(stmt)
+            is Label -> translate(stmt)
+            is BranchStatement -> translate(stmt)
+            is IfStatement -> translate(stmt)
+            is ForLoop -> forloopsAsmGen.translate(stmt)
+            is Continue -> out("  jmp  ${loopContinueLabels.peek()}")
+            is Break -> out("  jmp  ${loopEndLabels.peek()}")
+            is WhileLoop -> translate(stmt)
+            is RepeatLoop -> translate(stmt)
+            is WhenStatement -> translate(stmt)
+            is BuiltinFunctionStatementPlaceholder -> throw AssemblyError("builtin function should not have placeholder anymore?")
+            is AnonymousScope -> translate(stmt)
+            is Block -> throw AssemblyError("block should have been handled elsewhere")
+        }
+    }
+
+    private fun translate(stmt: IfStatement) {
+        expressionsAsmGen.translateExpression(stmt.condition)
+        translateTestStack(stmt.condition.inferType(program).typeOrElse(DataType.STRUCT))
+        val elseLabel = makeLabel("if_else")
+        val endLabel = makeLabel("if_end")
+        out("  beq  $elseLabel")
+        translate(stmt.truepart)
+        out("  jmp  $endLabel")
+        out(elseLabel)
+        translate(stmt.elsepart)
+        out(endLabel)
+    }
+
+    private fun translateTestStack(dataType: DataType) {
+        when(dataType) {
+            in ByteDatatypes -> out("  inx |  lda  $ESTACK_LO_HEX,x")
+            in WordDatatypes -> out("  inx |  lda  $ESTACK_LO_HEX,x |  ora  $ESTACK_HI_HEX,x")
+            DataType.FLOAT -> throw AssemblyError("conditional value should be an integer (boolean)")
+            else -> throw AssemblyError("non-numerical dt")
+        }
+    }
+
+    private fun translate(stmt: WhileLoop) {
+        val whileLabel = makeLabel("while")
+        val endLabel = makeLabel("whileend")
+        loopEndLabels.push(endLabel)
+        loopContinueLabels.push(whileLabel)
+        out(whileLabel)
+        // TODO optimize for the simple cases, can we avoid stack use?
+        expressionsAsmGen.translateExpression(stmt.condition)
+        val conditionDt = stmt.condition.inferType(program)
+        if(!conditionDt.isKnown)
+            throw AssemblyError("unknown condition dt")
+        if(conditionDt.typeOrElse(DataType.BYTE) in ByteDatatypes) {
+            out("  inx |  lda  $ESTACK_LO_HEX,x  |  beq  $endLabel")
+        } else {
+            out("""
+                inx
+                lda  $ESTACK_LO_HEX,x
+                bne  +
+                lda  $ESTACK_HI_HEX,x
+                beq  $endLabel
++  """)
+        }
+        translate(stmt.body)
+        out("  jmp  $whileLabel")
+        out(endLabel)
+        loopEndLabels.pop()
+        loopContinueLabels.pop()
+    }
+
+    private fun translate(stmt: RepeatLoop) {
+        val repeatLabel = makeLabel("repeat")
+        val endLabel = makeLabel("repeatend")
+        loopEndLabels.push(endLabel)
+        loopContinueLabels.push(repeatLabel)
+        out(repeatLabel)
+        // TODO optimize this for the simple cases, can we avoid stack use?
+        translate(stmt.body)
+        expressionsAsmGen.translateExpression(stmt.untilCondition)
+        val conditionDt = stmt.untilCondition.inferType(program)
+        if(!conditionDt.isKnown)
+            throw AssemblyError("unknown condition dt")
+        if(conditionDt.typeOrElse(DataType.BYTE) in ByteDatatypes) {
+            out("  inx |  lda  $ESTACK_LO_HEX,x  |  beq  $repeatLabel")
+        } else {
+            out("""
+                inx
+                lda  $ESTACK_LO_HEX,x
+                bne  +
+                lda  $ESTACK_HI_HEX,x
+                beq  $repeatLabel
++ """)
+        }
+        out(endLabel)
+        loopEndLabels.pop()
+        loopContinueLabels.pop()
+    }
+
+    private fun translate(stmt: WhenStatement) {
+        expressionsAsmGen.translateExpression(stmt.condition)
+        val endLabel = makeLabel("choice_end")
+        val choiceBlocks = mutableListOf<Pair<String, AnonymousScope>>()
+        val conditionDt = stmt.condition.inferType(program)
+        if(!conditionDt.isKnown)
+            throw AssemblyError("unknown condition dt")
+        if(conditionDt.typeOrElse(DataType.BYTE) in ByteDatatypes)
+            out("  inx |  lda  $ESTACK_LO_HEX,x")
+        else
+            out("  inx |  lda  $ESTACK_LO_HEX,x |  ldy  $ESTACK_HI_HEX,x")
+        for(choice in stmt.choices) {
+            val choiceLabel = makeLabel("choice")
+            if(choice.values==null) {
+                // the else choice
+                translate(choice.statements)
+                out("  jmp  $endLabel")
+            } else {
+                choiceBlocks.add(Pair(choiceLabel, choice.statements))
+                for (cv in choice.values!!) {
+                    val value = (cv as NumericLiteralValue).number.toInt()
+                    if(conditionDt.typeOrElse(DataType.BYTE) in ByteDatatypes) {
+                        out("  cmp  #${value.toHex()} |  beq  $choiceLabel")
+                    } else {
+                        out("""
+                            cmp  #<${value.toHex()}
+                            bne  +
+                            cpy  #>${value.toHex()}
+                            beq  $choiceLabel
++                            
+                            """)
+                    }
+                }
+            }
+        }
+        for(choiceBlock in choiceBlocks) {
+            out(choiceBlock.first)
+            translate(choiceBlock.second)
+            out("  jmp  $endLabel")
+        }
+        out(endLabel)
+    }
+
+    private fun translate(stmt: Label) {
+        out(stmt.name)
+    }
+
+    private fun translate(scope: AnonymousScope) {
+        // note: the variables defined in an anonymous scope have been moved to their defining subroutine's scope
+        scope.statements.forEach{ translate(it) }
+    }
+
+    private fun translate(stmt: BranchStatement) {
+        if(stmt.truepart.containsNoCodeNorVars() && stmt.elsepart.containsCodeOrVars())
+            throw AssemblyError("only else part contains code, shoud have been switched already")
+
+        val jump = stmt.truepart.statements.first() as? Jump
+        if(jump!=null) {
+            // branch with only a jump
+            val instruction = branchInstruction(stmt.condition, false)
+            out("  $instruction  ${getJumpTarget(jump)}")
+            translate(stmt.elsepart)
+        } else {
+            if(stmt.elsepart.containsNoCodeNorVars()) {
+                val instruction = branchInstruction(stmt.condition, true)
+                val elseLabel = makeLabel("branch_else")
+                out("  $instruction  $elseLabel")
+                translate(stmt.truepart)
+                out(elseLabel)
+            } else {
+                val instruction = branchInstruction(stmt.condition, false)
+                val trueLabel = makeLabel("branch_true")
+                val endLabel = makeLabel("branch_end")
+                out("  $instruction  $trueLabel")
+                translate(stmt.elsepart)
+                out("  jmp  $endLabel")
+                out(trueLabel)
+                translate(stmt.truepart)
+                out(endLabel)
+            }
+        }
+    }
+
+    private fun translate(stmt: Directive) {
+        when(stmt.directive) {
+            "%asminclude" -> {
+                val sourcecode = loadAsmIncludeFile(stmt.args[0].str!!, stmt.definingModule().source)
+                val scopeprefix = stmt.args[1].str ?: ""
+                if(!scopeprefix.isBlank())
+                    out("$scopeprefix\t.proc")
+                assemblyLines.add(sourcecode.trimEnd().trimStart('\n'))
+                if(!scopeprefix.isBlank())
+                    out("  .pend\n")
+            }
+            "%asmbinary" -> {
+                val offset = if(stmt.args.size>1) ", ${stmt.args[1].int}" else ""
+                val length = if(stmt.args.size>2) ", ${stmt.args[2].int}" else ""
+                out("  .binary \"${stmt.args[0].str}\" $offset $length")
+            }
+            "%breakpoint" -> {
+                val label = "_prog8_breakpoint_${breakpointLabels.size+1}"
+                breakpointLabels.add(label)
+                out("$label\tnop")
+            }
+        }
+    }
+
+    private fun translate(jmp: Jump) {
+        out("  jmp  ${getJumpTarget(jmp)}")
+    }
+
+    private fun getJumpTarget(jmp: Jump): String {
+        return when {
+            jmp.identifier!=null -> asmIdentifierName(jmp.identifier)
+            jmp.generatedLabel!=null -> jmp.generatedLabel
+            jmp.address!=null -> jmp.address.toHex()
+            else -> "????"
+        }
+    }
+
+    private fun translate(ret: Return) {
+        ret.value?.let { expressionsAsmGen.translateExpression(it) }
+        out("  rts")
+    }
+
+    private fun translate(asm: InlineAssembly) {
+        val assembly = asm.assembly.trimEnd().trimStart('\n')
+        assemblyLines.add(assembly)
+    }
+
+    internal fun translateArrayIndexIntoA(expr: ArrayIndexedExpression) {
+        when (val index = expr.arrayspec.index) {
+            is NumericLiteralValue -> throw AssemblyError("this should be optimized directly")
+            is RegisterExpr -> {
+                when (index.register) {
+                    Register.A -> {}
+                    Register.X -> out("  txa")
+                    Register.Y -> out("  tya")
+                }
+            }
+            is IdentifierReference -> {
+                val indexName = asmIdentifierName(index)
+                out("  lda  $indexName")
+            }
+            else -> {
+                expressionsAsmGen.translateExpression(index)
+                out("  inx |  lda  $ESTACK_LO_HEX,x")
+            }
+        }
+    }
+
+    internal fun translateExpression(expression: Expression) =
+            expressionsAsmGen.translateExpression(expression)
+
+    internal fun translateFunctioncallExpression(functionCall: FunctionCall, signature: FunctionSignature) =
+            builtinFunctionsAsmGen.translateFunctioncallExpression(functionCall, signature)
+
+    internal fun translateFunctionCall(functionCall: FunctionCall) =
+            functioncallAsmGen.translateFunctionCall(functionCall)
+
+    internal fun assignFromEvalResult(target: AssignTarget) =
+            assignmentAsmGen.assignFromEvalResult(target)
+
+    fun assignFromByteConstant(target: AssignTarget, value: Short) =
+            assignmentAsmGen.assignFromByteConstant(target, value)
+
+    fun assignFromWordConstant(target: AssignTarget, value: Int) =
+            assignmentAsmGen.assignFromWordConstant(target, value)
+
+    fun assignFromFloatConstant(target: AssignTarget, value: Double) =
+            assignmentAsmGen.assignFromFloatConstant(target, value)
+
+    fun assignFromByteVariable(target: AssignTarget, variable: IdentifierReference) =
+            assignmentAsmGen.assignFromByteVariable(target, variable)
+
+    fun assignFromWordVariable(target: AssignTarget, variable: IdentifierReference) =
+            assignmentAsmGen.assignFromWordVariable(target, variable)
+
+    fun assignFromFloatVariable(target: AssignTarget, variable: IdentifierReference) =
+            assignmentAsmGen.assignFromFloatVariable(target, variable)
+
+    fun assignFromRegister(target: AssignTarget, register: Register) =
+            assignmentAsmGen.assignFromRegister(target, register)
+
+    fun assignFromMemoryByte(target: AssignTarget, address: Int?, identifier: IdentifierReference?) =
+            assignmentAsmGen.assignFromMemoryByte(target, address, identifier)
+}

compiler/src/prog8/compiler/target/c64/codegen/AsmOptimizer.kt

@@ -1,6 +1,11 @@
-package prog8.compiler.target.c64
+package prog8.compiler.target.c64.codegen
+
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_HEX
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_PLUS1_HEX
+
+
+// note: see https://wiki.nesdev.com/w/index.php/6502_assembly_optimisations
 
-import prog8.compiler.toHex
 
 fun optimizeAssembly(lines: MutableList<String>): Int {
 
@@ -24,10 +29,19 @@ fun optimizeAssembly(lines: MutableList<String>): Int {
         numberOfOptimizations++
     }
 
+    removeLines = optimizeCmpSequence(linesByFour)
+    if(removeLines.isNotEmpty()) {
+        for (i in removeLines.reversed())
+            lines.removeAt(i)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
     removeLines = optimizeStoreLoadSame(linesByFour)
     if(removeLines.isNotEmpty()) {
         for (i in removeLines.reversed())
             lines.removeAt(i)
+        linesByFour = getLinesBy(lines, 4)
         numberOfOptimizations++
     }
 
@@ -36,24 +50,45 @@ fun optimizeAssembly(lines: MutableList<String>): Int {
     if(removeLines.isNotEmpty()) {
         for (i in removeLines.reversed())
             lines.removeAt(i)
+        linesByFourteen = getLinesBy(lines, 14)
         numberOfOptimizations++
     }
 
-    // TODO more assembly optimizations?
+    // TODO more assembly optimizations
 
     return numberOfOptimizations
 }
 
+fun optimizeCmpSequence(linesByFour: List<List<IndexedValue<String>>>): List<Int> {
+    // the when statement (on bytes) generates a sequence of:
+    //	 lda $ce01,x
+    //	 cmp #$20
+    //	 beq  check_prog8_s72choice_32
+    //	 lda $ce01,x
+    //	 cmp #$21
+    //	 beq  check_prog8_s73choice_33
+    // the repeated lda can be removed
+    val removeLines = mutableListOf<Int>()
+    for(lines in linesByFour) {
+        if(lines[0].value.trim()=="lda  $ESTACK_LO_PLUS1_HEX,x" &&
+                lines[1].value.trim().startsWith("cmp ") &&
+                lines[2].value.trim().startsWith("beq ") &&
+                lines[3].value.trim()=="lda  $ESTACK_LO_PLUS1_HEX,x") {
+            removeLines.add(lines[3].index) // remove the second lda
+        }
+    }
+    return removeLines
+}
+
 fun optimizeUselessStackByteWrites(linesByFour: List<List<IndexedValue<String>>>): List<Int> {
     // sta on stack, dex, inx, lda from stack -> eliminate this useless stack byte write
     // this is a lot harder for word values because the instruction sequence varies.
     val removeLines = mutableListOf<Int>()
     for(lines in linesByFour) {
-        if(lines[0].value.trim()=="sta  ${ESTACK_LO.toHex()},x" &&
+        if(lines[0].value.trim()=="sta  $ESTACK_LO_HEX,x" &&
                 lines[1].value.trim()=="dex" &&
                 lines[2].value.trim()=="inx" &&
-                lines[3].value.trim()=="lda  ${ESTACK_LO.toHex()},x") {
-            removeLines.add(lines[0].index)
+                lines[3].value.trim()=="lda  $ESTACK_LO_HEX,x") {
             removeLines.add(lines[1].index)
             removeLines.add(lines[2].index)
             removeLines.add(lines[3].index)
@@ -66,7 +101,7 @@ fun optimizeSameAssignments(linesByFourteen: List<List<IndexedValue<String>>>):
 
     // optimize sequential assignments of the isSameAs value to various targets (bytes, words, floats)
     // the float one is the one that requires 2*7=14 lines of code to check...
-    // @todo a better place to do this is in the Compiler instead and work on opcodes, and never even create the inefficient asm...
+    // @todo a better place to do this is in the Compiler instead and transform the Ast, or the AsmGen, and never even create the inefficient asm in the first place...
 
     val removeLines = mutableListOf<Int>()
     for (pair in linesByFourteen) {
@@ -128,7 +163,7 @@ fun optimizeSameAssignments(linesByFourteen: List<List<IndexedValue<String>>>):
 }
 
 private fun getLinesBy(lines: MutableList<String>, windowSize: Int) =
-// all lines (that aren't empty or comments) in sliding pairs of 2
+// all lines (that aren't empty or comments) in sliding windows of certain size
         lines.withIndex().filter { it.value.isNotBlank() && !it.value.trimStart().startsWith(';') }.windowed(windowSize, partialWindows = false)
 
 private fun optimizeStoreLoadSame(linesByFour: List<List<IndexedValue<String>>>): List<Int> {

compiler/src/prog8/compiler/target/c64/codegen/AssignmentAsmGen.kt

@@ -0,0 +1,750 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.statements.AssignTarget
+import prog8.ast.statements.Assignment
+import prog8.ast.statements.DirectMemoryWrite
+import prog8.ast.statements.VarDecl
+import prog8.compiler.toHex
+import prog8.compiler.AssemblyError
+import prog8.compiler.target.c64.C64MachineDefinition
+import prog8.compiler.target.c64.C64MachineDefinition.C64Zeropage
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_HI_HEX
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_HEX
+
+
+internal class AssignmentAsmGen(private val program: Program, private val asmgen: AsmGen) {
+
+    internal fun translate(assign: Assignment) {
+        if(assign.aug_op!=null)
+            throw AssemblyError("aug-op assignments should have been transformed to normal ones")
+
+        when(assign.value) {
+            is NumericLiteralValue -> {
+                val numVal = assign.value as NumericLiteralValue
+                when(numVal.type) {
+                    DataType.UBYTE, DataType.BYTE -> assignFromByteConstant(assign.target, numVal.number.toShort())
+                    DataType.UWORD, DataType.WORD -> assignFromWordConstant(assign.target, numVal.number.toInt())
+                    DataType.FLOAT -> assignFromFloatConstant(assign.target, numVal.number.toDouble())
+                    else -> throw AssemblyError("weird numval type")
+                }
+            }
+            is RegisterExpr -> {
+                assignFromRegister(assign.target, (assign.value as RegisterExpr).register)
+            }
+            is IdentifierReference -> {
+                val type = assign.target.inferType(program, assign).typeOrElse(DataType.STRUCT)
+                when(type) {
+                    DataType.UBYTE, DataType.BYTE -> assignFromByteVariable(assign.target, assign.value as IdentifierReference)
+                    DataType.UWORD, DataType.WORD -> assignFromWordVariable(assign.target, assign.value as IdentifierReference)
+                    DataType.FLOAT -> assignFromFloatVariable(assign.target, assign.value as IdentifierReference)
+                    else -> throw AssemblyError("unsupported assignment target type $type")
+                }
+            }
+            is AddressOf -> {
+                val identifier = (assign.value as AddressOf).identifier
+                assignFromAddressOf(assign.target, identifier)
+            }
+            is DirectMemoryRead -> {
+                val read = (assign.value as DirectMemoryRead)
+                when(read.addressExpression) {
+                    is NumericLiteralValue -> {
+                        val address = (read.addressExpression as NumericLiteralValue).number.toInt()
+                        assignFromMemoryByte(assign.target, address, null)
+                    }
+                    is IdentifierReference -> {
+                        assignFromMemoryByte(assign.target, null, read.addressExpression as IdentifierReference)
+                    }
+                    else -> {
+                        asmgen.translateExpression(read.addressExpression)
+                        TODO("read memory byte from result and put that in ${assign.target}")
+                    }
+                }
+            }
+            is PrefixExpression -> {
+                // TODO optimize common cases
+                asmgen.translateExpression(assign.value as PrefixExpression)
+                assignFromEvalResult(assign.target)
+            }
+            is BinaryExpression -> {
+                // TODO optimize common cases
+                asmgen.translateExpression(assign.value as BinaryExpression)
+                assignFromEvalResult(assign.target)
+            }
+            is ArrayIndexedExpression -> {
+                // TODO optimize common cases
+                val arrayExpr = assign.value as ArrayIndexedExpression
+                val arrayDt = arrayExpr.identifier.targetVarDecl(program.namespace)!!.datatype
+                val index = arrayExpr.arrayspec.index
+                if(index is NumericLiteralValue) {
+                    // constant array index value
+                    val arrayVarName = asmgen.asmIdentifierName(arrayExpr.identifier)
+                    val indexValue = index.number.toInt() * ArrayElementTypes.getValue(arrayDt).memorySize()
+                    when (arrayDt) {
+                        DataType.STR, DataType.ARRAY_UB, DataType.ARRAY_B ->
+                            asmgen.out("  lda  $arrayVarName+$indexValue |  sta  $ESTACK_LO_HEX,x |  dex")
+                        DataType.ARRAY_UW, DataType.ARRAY_W ->
+                            asmgen.out("  lda  $arrayVarName+$indexValue |  sta  $ESTACK_LO_HEX,x |  lda  $arrayVarName+$indexValue+1 |  sta  $ESTACK_HI_HEX,x | dex")
+                        DataType.ARRAY_F ->
+                            asmgen.out("  lda  #<$arrayVarName+$indexValue |  ldy  #>$arrayVarName+$indexValue |  jsr  c64flt.push_float")
+                        else ->
+                            throw AssemblyError("weird array type")
+                    }
+                } else {
+                    asmgen.translateArrayIndexIntoA(arrayExpr)
+                    asmgen.readAndPushArrayvalueWithIndexA(arrayDt, arrayExpr.identifier)
+                }
+                assignFromEvalResult(assign.target)
+            }
+            is TypecastExpression -> {
+                val cast = assign.value as TypecastExpression
+                val sourceType = cast.expression.inferType(program)
+                val targetType = assign.target.inferType(program, assign)
+                if(sourceType.isKnown && targetType.isKnown &&
+                        (sourceType.typeOrElse(DataType.STRUCT) in ByteDatatypes && targetType.typeOrElse(DataType.STRUCT) in ByteDatatypes) ||
+                        (sourceType.typeOrElse(DataType.STRUCT) in WordDatatypes && targetType.typeOrElse(DataType.STRUCT) in WordDatatypes)) {
+                    // no need for a type cast
+                    assign.value = cast.expression
+                    translate(assign)
+                } else {
+                    asmgen.translateExpression(assign.value as TypecastExpression)
+                    assignFromEvalResult(assign.target)
+                }
+            }
+            is FunctionCall -> {
+                asmgen.translateExpression(assign.value as FunctionCall)
+                assignFromEvalResult(assign.target)
+            }
+            is ArrayLiteralValue, is StringLiteralValue -> TODO("string/array/struct assignment?")
+            is StructLiteralValue -> throw AssemblyError("struct literal value assignment should have been flattened")
+            is RangeExpr -> throw AssemblyError("range expression should have been changed into array values")
+        }
+    }
+
+    internal fun assignFromEvalResult(target: AssignTarget) {
+        val targetIdent = target.identifier
+        when {
+            target.register!=null -> {
+                if(target.register== Register.X)
+                    throw AssemblyError("can't pop into X register - use variable instead")
+                asmgen.out(" inx | ld${target.register.name.toLowerCase()}  $ESTACK_LO_HEX,x ")
+            }
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                val targetDt = targetIdent.inferType(program).typeOrElse(DataType.STRUCT)
+                when(targetDt) {
+                    DataType.UBYTE, DataType.BYTE -> {
+                        asmgen.out(" inx | lda  $ESTACK_LO_HEX,x  | sta  $targetName")
+                    }
+                    DataType.UWORD, DataType.WORD -> {
+                        asmgen.out("""
+                            inx
+                            lda  $ESTACK_LO_HEX,x
+                            sta  $targetName
+                            lda  $ESTACK_HI_HEX,x
+                            sta  $targetName+1
+                        """)
+                    }
+                    DataType.FLOAT -> {
+                        asmgen.out("""
+                            lda  #<$targetName
+                            ldy  #>$targetName
+                            jsr  c64flt.pop_float
+                        """)
+                    }
+                    else -> throw AssemblyError("weird target variable type $targetDt")
+                }
+            }
+            target.memoryAddress!=null -> {
+                asmgen.out("  inx  | ldy  $ESTACK_LO_HEX,x")
+                storeRegisterInMemoryAddress(Register.Y, target.memoryAddress)
+            }
+            target.arrayindexed!=null -> {
+                val arrayDt = target.arrayindexed!!.identifier.targetVarDecl(program.namespace)!!.datatype
+                val arrayVarName = asmgen.asmIdentifierName(target.arrayindexed!!.identifier)
+                asmgen.translateExpression(target.arrayindexed!!.arrayspec.index)
+                asmgen.out("  inx |  lda  $ESTACK_LO_HEX,x")
+                popAndWriteArrayvalueWithIndexA(arrayDt, arrayVarName)
+            }
+            else -> throw AssemblyError("weird assignment target $target")
+        }
+    }
+
+    internal fun assignFromAddressOf(target: AssignTarget, name: IdentifierReference) {
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        val struct = name.memberOfStruct(program.namespace)
+        val sourceName = if(struct!=null) {
+            // take the address of the first struct member instead
+            val decl = name.targetVarDecl(program.namespace)!!
+            val firstStructMember = struct.nameOfFirstMember()
+            // find the flattened var that belongs to this first struct member
+            val firstVarName = listOf(decl.name, firstStructMember)
+            val firstVar = name.definingScope().lookup(firstVarName, name) as VarDecl
+            firstVar.name
+        } else {
+            asmgen.fixNameSymbols(name.nameInSource.joinToString ("."))
+        }
+
+        when {
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                asmgen.out("""
+                        lda  #<$sourceName
+                        ldy  #>$sourceName
+                        sta  $targetName
+                        sty  $targetName+1
+                    """)
+            }
+            target.memoryAddress!=null -> {
+                TODO("assign address $sourceName to memory word $target")
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                TODO("assign address $sourceName to array $targetName [ $index ]")
+            }
+            else -> TODO("assign address $sourceName to $target")
+        }
+    }
+
+    internal fun assignFromWordVariable(target: AssignTarget, variable: IdentifierReference) {
+        val sourceName = asmgen.asmIdentifierName(variable)
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        when {
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                asmgen.out("""
+                    lda  $sourceName
+                    ldy  $sourceName+1
+                    sta  $targetName
+                    sty  $targetName+1
+                """)
+            }
+            target.memoryAddress!=null -> {
+                TODO("assign wordvar $sourceName to memory ${target.memoryAddress}")
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                asmgen.out("  lda  $sourceName |  sta  $ESTACK_LO_HEX,x |  lda  $sourceName+1 |  sta  $ESTACK_HI_HEX,x |  dex")
+                asmgen.translateExpression(index)
+                asmgen.out("  inx |  lda  $ESTACK_LO_HEX,x")
+                val arrayDt = targetArrayIdx.identifier.inferType(program).typeOrElse(DataType.STRUCT)
+                popAndWriteArrayvalueWithIndexA(arrayDt, targetName)
+            }
+            else -> TODO("assign wordvar to $target")
+        }
+    }
+
+    internal fun assignFromFloatVariable(target: AssignTarget, variable: IdentifierReference) {
+        val sourceName = asmgen.asmIdentifierName(variable)
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        when {
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                asmgen.out("""
+                    lda  $sourceName
+                    sta  $targetName
+                    lda  $sourceName+1
+                    sta  $targetName+1
+                    lda  $sourceName+2
+                    sta  $targetName+2
+                    lda  $sourceName+3
+                    sta  $targetName+3
+                    lda  $sourceName+4
+                    sta  $targetName+4
+                """)
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                asmgen.out("  lda  #<$sourceName |  ldy  #>$sourceName |  jsr  c64flt.push_float")
+                asmgen.translateExpression(index)
+                asmgen.out("  lda  #<$targetName |  ldy  #>$targetName |  jsr  c64flt.pop_float_to_indexed_var")
+            }
+            else -> TODO("assign floatvar to $target")
+        }
+    }
+
+    internal fun assignFromByteVariable(target: AssignTarget, variable: IdentifierReference) {
+        val sourceName = asmgen.asmIdentifierName(variable)
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        when {
+            target.register!=null -> {
+                asmgen.out("  ld${target.register.name.toLowerCase()}  $sourceName")
+            }
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                asmgen.out("""
+                    lda  $sourceName
+                    sta  $targetName
+                    """)
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                val arrayDt = targetArrayIdx.identifier.inferType(program).typeOrElse(DataType.STRUCT)
+                asmgen.out("  lda  $sourceName |  sta  $ESTACK_LO_HEX,x |  dex")
+                asmgen.translateExpression(index)
+                asmgen.out("  inx |  lda  $ESTACK_LO_HEX,x")
+                popAndWriteArrayvalueWithIndexA(arrayDt, targetName)
+            }
+            target.memoryAddress != null -> {
+                val addressExpr = target.memoryAddress.addressExpression
+                val addressLv = addressExpr as? NumericLiteralValue
+                when {
+                    addressLv != null -> asmgen.out("  lda  $sourceName |  sta  ${addressLv.number.toHex()}")
+                    addressExpr is IdentifierReference -> {
+                        val targetName = asmgen.asmIdentifierName(addressExpr)
+                        asmgen.out("  lda  $sourceName |  sta  $targetName")
+                    }
+                    else -> {
+                        asmgen.translateExpression(addressExpr)
+                        asmgen.out("""
+     inx
+     lda  $ESTACK_LO_HEX,x
+     ldy  $ESTACK_HI_HEX,x
+     sta  (+) +1
+     sty  (+) +2
+     lda  $sourceName
++    sta  ${65535.toHex()}      ; modified              
+                            """)
+                    }
+                }
+            }
+            else -> TODO("assign bytevar to $target")
+        }
+    }
+
+    internal fun assignFromRegister(target: AssignTarget, register: Register) {
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        when {
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                asmgen.out("  st${register.name.toLowerCase()}  $targetName")
+            }
+            target.register!=null -> {
+                when(register) {
+                    Register.A -> when(target.register) {
+                        Register.A -> {}
+                        Register.X -> asmgen.out("  tax")
+                        Register.Y -> asmgen.out("  tay")
+                    }
+                    Register.X -> when(target.register) {
+                        Register.A -> asmgen.out("  txa")
+                        Register.X -> {}
+                        Register.Y -> asmgen.out("  txy")
+                    }
+                    Register.Y -> when(target.register) {
+                        Register.A -> asmgen.out("  tya")
+                        Register.X -> asmgen.out("  tyx")
+                        Register.Y -> {}
+                    }
+                }
+            }
+            target.memoryAddress!=null -> {
+                storeRegisterInMemoryAddress(register, target.memoryAddress)
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                when (index) {
+                    is NumericLiteralValue -> {
+                        val memindex = index.number.toInt()
+                        when(register) {
+                            Register.A -> asmgen.out("  sta  $targetName+$memindex")
+                            Register.X -> asmgen.out("  stx  $targetName+$memindex")
+                            Register.Y -> asmgen.out("  sty  $targetName+$memindex")
+                        }
+                    }
+                    is RegisterExpr -> {
+                        when(register) {
+                            Register.A -> asmgen.out("  sta  ${C64Zeropage.SCRATCH_B1}")
+                            Register.X -> asmgen.out("  stx  ${C64Zeropage.SCRATCH_B1}")
+                            Register.Y -> asmgen.out("  sty  ${C64Zeropage.SCRATCH_B1}")
+                        }
+                        when(index.register) {
+                            Register.A -> {}
+                            Register.X -> asmgen.out("  txa")
+                            Register.Y -> asmgen.out("  tya")
+                        }
+                        asmgen.out("""
+                            tay
+                            lda  ${C64Zeropage.SCRATCH_B1}
+                            sta  $targetName,y
+                            """)
+                    }
+                    is IdentifierReference -> {
+                        when(register) {
+                            Register.A -> asmgen.out("  sta  ${C64Zeropage.SCRATCH_B1}")
+                            Register.X -> asmgen.out("  stx  ${C64Zeropage.SCRATCH_B1}")
+                            Register.Y -> asmgen.out("  sty  ${C64Zeropage.SCRATCH_B1}")
+                        }
+                        asmgen.out("""
+                            lda  ${asmgen.asmIdentifierName(index)}
+                            tay
+                            lda  ${C64Zeropage.SCRATCH_B1}
+                            sta  $targetName,y
+                        """)
+                    }
+                    else -> {
+                        asmgen.saveRegister(register)
+                        asmgen.translateExpression(index)
+                        asmgen.restoreRegister(register)
+                        when(register) {
+                            Register.A -> asmgen.out("  sta  ${C64Zeropage.SCRATCH_B1}")
+                            Register.X -> asmgen.out("  stx  ${C64Zeropage.SCRATCH_B1}")
+                            Register.Y -> asmgen.out("  sty  ${C64Zeropage.SCRATCH_B1}")
+                        }
+                        asmgen.out("""
+                            inx
+                            lda  $ESTACK_LO_HEX,x
+                            tay
+                            lda  ${C64Zeropage.SCRATCH_B1}
+                            sta  $targetName,y  
+                        """)
+                    }
+                }
+            }
+            else -> TODO("assign register $register to $target")
+        }
+    }
+
+    private fun storeRegisterInMemoryAddress(register: Register, memoryAddress: DirectMemoryWrite) {
+        val addressExpr = memoryAddress.addressExpression
+        val addressLv = addressExpr as? NumericLiteralValue
+        val registerName = register.name.toLowerCase()
+        when {
+            addressLv != null -> asmgen.out("  st$registerName  ${addressLv.number.toHex()}")
+            addressExpr is IdentifierReference -> {
+                val targetName = asmgen.asmIdentifierName(addressExpr)
+                when(register) {
+                    Register.A -> asmgen.out("""
+                        ldy  $targetName
+                        sty  ${C64Zeropage.SCRATCH_W1}
+                        ldy  $targetName+1
+                        sty  ${C64Zeropage.SCRATCH_W1+1}
+                        ldy  #0
+                        sta  (${C64Zeropage.SCRATCH_W1}),y
+                        """)
+                    Register.X -> asmgen.out("""
+                        txa
+                        ldy  $targetName
+                        sty  ${C64Zeropage.SCRATCH_W1}
+                        ldy  $targetName+1
+                        sty  ${C64Zeropage.SCRATCH_W1+1}
+                        ldy  #0
+                        sta  (${C64Zeropage.SCRATCH_W1}),y
+                        """)
+                    Register.Y -> asmgen.out("""
+                        tya
+                        ldy  $targetName
+                        sty  ${C64Zeropage.SCRATCH_W1}
+                        ldy  $targetName+1
+                        sty  ${C64Zeropage.SCRATCH_W1+1}
+                        ldy  #0
+                        sta  (${C64Zeropage.SCRATCH_W1}),y
+                        """)
+                }
+            }
+            else -> {
+                asmgen.saveRegister(register)
+                asmgen.translateExpression(addressExpr)
+                asmgen.restoreRegister(register)
+                when (register) {
+                    Register.A -> asmgen.out("  tay")
+                    Register.X -> throw AssemblyError("can't use X register here")
+                    Register.Y -> {}
+                }
+                asmgen.out("""
+     inx
+     lda  $ESTACK_LO_HEX,x
+     sta  (+) +1
+     lda  $ESTACK_HI_HEX,x
+     sta  (+) +2
++    sty  ${65535.toHex()}      ; modified              
+                            """)
+            }
+        }
+    }
+
+    internal fun assignFromWordConstant(target: AssignTarget, word: Int) {
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        when {
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                if(word ushr 8 == word and 255) {
+                    // lsb=msb
+                    asmgen.out("""
+                    lda  #${(word and 255).toHex()}
+                    sta  $targetName
+                    sta  $targetName+1
+                """)
+                } else {
+                    asmgen.out("""
+                    lda  #<${word.toHex()}
+                    ldy  #>${word.toHex()}
+                    sta  $targetName
+                    sty  $targetName+1
+                """)
+                }
+            }
+            target.memoryAddress!=null -> {
+                TODO("assign word $word to memory ${target.memoryAddress}")
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                // TODO optimize common cases
+                asmgen.translateExpression(index)
+                asmgen.out("""
+                    inx
+                    lda  $ESTACK_LO_HEX,x
+                    asl  a
+                    tay
+                    lda  #<${word.toHex()}
+                    sta  $targetName,y
+                    lda  #>${word.toHex()}
+                    sta  $targetName+1,y
+                """)
+            }
+            else -> TODO("assign word $word to $target")
+        }
+    }
+
+    internal fun assignFromByteConstant(target: AssignTarget, byte: Short) {
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        when {
+            target.register!=null -> {
+                asmgen.out("  ld${target.register.name.toLowerCase()}  #${byte.toHex()}")
+            }
+            targetIdent!=null -> {
+                val targetName = asmgen.asmIdentifierName(targetIdent)
+                asmgen.out(" lda  #${byte.toHex()} |  sta  $targetName ")
+            }
+            target.memoryAddress!=null -> {
+                asmgen.out("  ldy  #${byte.toHex()}")
+                storeRegisterInMemoryAddress(Register.Y, target.memoryAddress)
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                // TODO optimize common cases
+                asmgen.translateExpression(index)
+                asmgen.out("""
+                    inx
+                    ldy  $ESTACK_LO_HEX,x
+                    lda  #${byte.toHex()}
+                    sta  $targetName,y
+                """)
+            }
+            else -> TODO("assign byte $byte to $target")
+        }
+    }
+
+    internal fun assignFromFloatConstant(target: AssignTarget, float: Double) {
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        if(float==0.0) {
+            // optimized case for float zero
+            when {
+                targetIdent != null -> {
+                    val targetName = asmgen.asmIdentifierName(targetIdent)
+                    asmgen.out("""
+                            lda  #0
+                            sta  $targetName
+                            sta  $targetName+1
+                            sta  $targetName+2
+                            sta  $targetName+3
+                            sta  $targetName+4
+                        """)
+                }
+                targetArrayIdx!=null -> {
+                    val index = targetArrayIdx.arrayspec.index
+                    val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                    if(index is NumericLiteralValue) {
+                        val indexValue = index.number.toInt() * C64MachineDefinition.FLOAT_MEM_SIZE
+                        asmgen.out("""
+                            lda  #0
+                            sta  $targetName+$indexValue
+                            sta  $targetName+$indexValue+1
+                            sta  $targetName+$indexValue+2
+                            sta  $targetName+$indexValue+3
+                            sta  $targetName+$indexValue+4
+                        """)
+                    } else {
+                        asmgen.translateExpression(index)
+                        asmgen.out("""
+                        inx
+                        lda  $ESTACK_LO_HEX,x
+                        asl  a
+                        asl  a
+                        clc
+                        adc  $ESTACK_LO_HEX,x
+                        tay
+                        lda  #0
+                        sta  $targetName,y
+                        sta  $targetName+1,y
+                        sta  $targetName+2,y
+                        sta  $targetName+3,y
+                        sta  $targetName+4,y
+                    """) // TODO use a subroutine for this
+                    }
+                }
+                else -> TODO("assign float 0.0 to $target")
+            }
+        } else {
+            // non-zero value
+            val constFloat = asmgen.getFloatConst(float)
+            when {
+                targetIdent != null -> {
+                    val targetName = asmgen.asmIdentifierName(targetIdent)
+                    asmgen.out("""
+                            lda  $constFloat
+                            sta  $targetName
+                            lda  $constFloat+1
+                            sta  $targetName+1
+                            lda  $constFloat+2
+                            sta  $targetName+2
+                            lda  $constFloat+3
+                            sta  $targetName+3
+                            lda  $constFloat+4
+                            sta  $targetName+4
+                        """)
+                }
+                targetArrayIdx!=null -> {
+                    val index = targetArrayIdx.arrayspec.index
+                    val arrayVarName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                    if(index is NumericLiteralValue) {
+                        val indexValue = index.number.toInt() * C64MachineDefinition.FLOAT_MEM_SIZE
+                        asmgen.out("""
+                            lda  $constFloat
+                            sta  $arrayVarName+$indexValue
+                            lda  $constFloat+1
+                            sta  $arrayVarName+$indexValue+1
+                            lda  $constFloat+2
+                            sta  $arrayVarName+$indexValue+2
+                            lda  $constFloat+3
+                            sta  $arrayVarName+$indexValue+3
+                            lda  $constFloat+4
+                            sta  $arrayVarName+$indexValue+4
+                        """)
+                    } else {
+                        asmgen.translateArrayIndexIntoA(targetArrayIdx)
+                        asmgen.out("""
+                            sta  ${C64Zeropage.SCRATCH_REG}
+                            asl  a
+                            asl  a
+                            clc
+                            adc  ${C64Zeropage.SCRATCH_REG}
+                            tay
+                            lda  $constFloat
+                            sta  $arrayVarName,y
+                            lda  $constFloat+1
+                            sta  $arrayVarName+1,y
+                            lda  $constFloat+2
+                            sta  $arrayVarName+2,y
+                            lda  $constFloat+3
+                            sta  $arrayVarName+3,y
+                            lda  $constFloat+4
+                            sta  $arrayVarName+4,y
+                        """)        // TODO use a subroutine for this
+                    }
+                }
+                else -> TODO("assign float $float to $target")
+            }
+        }
+    }
+
+    internal fun assignFromMemoryByte(target: AssignTarget, address: Int?, identifier: IdentifierReference?) {
+        val targetIdent = target.identifier
+        val targetArrayIdx = target.arrayindexed
+        if(address!=null) {
+            when {
+                target.register!=null -> {
+                    asmgen.out("  ld${target.register.name.toLowerCase()}  ${address.toHex()}")
+                }
+                targetIdent!=null -> {
+                    val targetName = asmgen.asmIdentifierName(targetIdent)
+                    asmgen.out("""
+                        lda  ${address.toHex()}
+                        sta  $targetName
+                        """)
+                }
+                target.memoryAddress!=null -> {
+                    asmgen.out("  ldy  ${address.toHex()}")
+                    storeRegisterInMemoryAddress(Register.Y, target.memoryAddress)
+                }
+                targetArrayIdx!=null -> {
+                    val index = targetArrayIdx.arrayspec.index
+                    val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                    TODO("assign memory byte at $address to array $targetName [ $index ]")
+                }
+                else -> TODO("assign memory byte $target")
+            }
+        }
+        else if(identifier!=null) {
+            val sourceName = asmgen.asmIdentifierName(identifier)
+            when {
+                target.register!=null -> {
+                    asmgen.out("""
+                        ldy  #0
+                        lda  ($sourceName),y
+                    """)
+                    when(target.register){
+                        Register.A -> {}
+                        Register.X -> asmgen.out("  tax")
+                        Register.Y -> asmgen.out("  tay")
+                    }
+                }
+                targetIdent!=null -> {
+                    val targetName = asmgen.asmIdentifierName(targetIdent)
+                    asmgen.out("""
+                        ldy  #0
+                        lda  ($sourceName),y
+                        sta  $targetName
+                    """)
+                }
+                target.memoryAddress!=null -> {
+                    asmgen.out("  ldy  $sourceName")
+                    storeRegisterInMemoryAddress(Register.Y, target.memoryAddress)
+                }
+                targetArrayIdx!=null -> {
+                    val index = targetArrayIdx.arrayspec.index
+                    val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                    TODO("assign memory byte $sourceName to array $targetName [ $index ]")
+                }
+                else -> TODO("assign memory byte $target")
+            }
+        }
+    }
+
+    private fun popAndWriteArrayvalueWithIndexA(arrayDt: DataType, variablename: String) {
+        when (arrayDt) {
+            DataType.STR, DataType.ARRAY_UB, DataType.ARRAY_B ->
+                asmgen.out("  tay |  inx |  lda  $ESTACK_LO_HEX,x  | sta  $variablename,y")
+            DataType.ARRAY_UW, DataType.ARRAY_W ->
+                asmgen.out("  asl  a |  tay |  inx |  lda  $ESTACK_LO_HEX,x |  sta  $variablename,y |  lda  $ESTACK_HI_HEX,x |  sta $variablename+1,y")
+            DataType.ARRAY_F ->
+                // index * 5 is done in the subroutine that's called
+                asmgen.out("""
+                    sta  $ESTACK_LO_HEX,x
+                    dex
+                    lda  #<$variablename
+                    ldy  #>$variablename
+                    jsr  c64flt.pop_float_to_indexed_var
+                """)
+            else ->
+                throw AssemblyError("weird array type")
+        }
+    }
+}

compiler/src/prog8/compiler/target/c64/codegen/BuiltinFunctionsAsmGen.kt

@@ -0,0 +1,603 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.IFunctionCall
+import prog8.ast.Program
+import prog8.ast.base.ByteDatatypes
+import prog8.ast.base.DataType
+import prog8.ast.base.Register
+import prog8.ast.base.WordDatatypes
+import prog8.ast.expressions.*
+import prog8.ast.statements.AssignTarget
+import prog8.ast.statements.FunctionCallStatement
+import prog8.compiler.target.c64.C64MachineDefinition.C64Zeropage
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_HI_HEX
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_HI_PLUS1_HEX
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_HEX
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_PLUS1_HEX
+import prog8.compiler.toHex
+import prog8.compiler.AssemblyError
+import prog8.functions.FunctionSignature
+
+internal class BuiltinFunctionsAsmGen(private val program: Program, private val asmgen: AsmGen) {
+
+    internal fun translateFunctioncallExpression(fcall: FunctionCall, func: FunctionSignature) {
+        translateFunctioncall(fcall, func, false)
+    }
+
+    internal fun translateFunctioncallStatement(fcall: FunctionCallStatement, func: FunctionSignature) {
+        translateFunctioncall(fcall, func, true)
+    }
+
+    private fun translateFunctioncall(fcall: IFunctionCall, func: FunctionSignature, discardResult: Boolean) {
+        val functionName = fcall.target.nameInSource.last()
+        if (discardResult) {
+            if (func.pure)
+                return  // can just ignore the whole function call altogether
+            else if (func.returntype != null)
+                throw AssemblyError("discarding result of non-pure function $fcall")
+        }
+
+        when (functionName) {
+            "msb" -> {
+                val arg = fcall.args.single()
+                if (arg.inferType(program).typeOrElse(DataType.STRUCT) !in WordDatatypes)
+                    throw AssemblyError("msb required word argument")
+                if (arg is NumericLiteralValue)
+                    throw AssemblyError("should have been const-folded")
+                if (arg is IdentifierReference) {
+                    val sourceName = asmgen.asmIdentifierName(arg)
+                    asmgen.out("  lda  $sourceName+1 |  sta  $ESTACK_LO_HEX,x |  dex")
+                } else {
+                    asmgen.translateExpression(arg)
+                    asmgen.out("  lda  $ESTACK_HI_PLUS1_HEX,x |  sta  $ESTACK_LO_PLUS1_HEX,x")
+                }
+            }
+            "mkword" -> {
+                translateFunctionArguments(fcall.args, func)
+                asmgen.out("  inx | lda  $ESTACK_LO_HEX,x  | sta  $ESTACK_HI_PLUS1_HEX,x")
+            }
+            "abs" -> {
+                translateFunctionArguments(fcall.args, func)
+                val dt = fcall.args.single().inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    in ByteDatatypes -> asmgen.out("  jsr  prog8_lib.abs_b")
+                    in WordDatatypes -> asmgen.out("  jsr  prog8_lib.abs_w")
+                    DataType.FLOAT -> asmgen.out("  jsr  c64flt.abs_f")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "swap" -> {
+                val first = fcall.args[0]
+                val second = fcall.args[1]
+                asmgen.translateExpression(first)
+                asmgen.translateExpression(second)
+                // pop in reverse order
+                val firstTarget = AssignTarget.fromExpr(first)
+                val secondTarget = AssignTarget.fromExpr(second)
+                asmgen.assignFromEvalResult(firstTarget)
+                asmgen.assignFromEvalResult(secondTarget)
+            }
+            "strlen" -> {
+                outputPushAddressOfIdentifier(fcall.args[0])
+                asmgen.out("  jsr  prog8_lib.func_strlen")
+            }
+            "min", "max", "sum" -> {
+                outputPushAddressAndLenghtOfArray(fcall.args[0])
+                val dt = fcall.args.single().inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.ARRAY_UB, DataType.STR -> asmgen.out("  jsr  prog8_lib.func_${functionName}_ub")
+                    DataType.ARRAY_B -> asmgen.out("  jsr  prog8_lib.func_${functionName}_b")
+                    DataType.ARRAY_UW -> asmgen.out("  jsr  prog8_lib.func_${functionName}_uw")
+                    DataType.ARRAY_W -> asmgen.out("  jsr  prog8_lib.func_${functionName}_w")
+                    DataType.ARRAY_F -> asmgen.out("  jsr  c64flt.func_${functionName}_f")
+                    else -> throw AssemblyError("weird type $dt")
+                }
+            }
+            "any", "all" -> {
+                outputPushAddressAndLenghtOfArray(fcall.args[0])
+                val dt = fcall.args.single().inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.ARRAY_B, DataType.ARRAY_UB, DataType.STR -> asmgen.out("  jsr  prog8_lib.func_${functionName}_b")
+                    DataType.ARRAY_UW, DataType.ARRAY_W -> asmgen.out("  jsr  prog8_lib.func_${functionName}_w")
+                    DataType.ARRAY_F -> asmgen.out("  jsr  c64flt.func_${functionName}_f")
+                    else -> throw AssemblyError("weird type $dt")
+                }
+            }
+            "sgn" -> {
+                translateFunctionArguments(fcall.args, func)
+                val dt = fcall.args.single().inferType(program)
+                when(dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.UBYTE -> asmgen.out("  jsr  math.sign_ub")
+                    DataType.BYTE -> asmgen.out("  jsr  math.sign_b")
+                    DataType.UWORD -> asmgen.out("  jsr  math.sign_uw")
+                    DataType.WORD -> asmgen.out("  jsr  math.sign_w")
+                    DataType.FLOAT -> asmgen.out("  jsr  c64flt.sign_f")
+                    else -> throw AssemblyError("weird type $dt")
+                }
+            }
+            "sin", "cos", "tan", "atan",
+            "ln", "log2", "sqrt", "rad",
+            "deg", "round", "floor", "ceil",
+            "rdnf" -> {
+                translateFunctionArguments(fcall.args, func)
+                asmgen.out("  jsr  c64flt.func_$functionName")
+            }
+            "lsl" -> {
+                // in-place
+                val what = fcall.args.single()
+                val dt = what.inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    in ByteDatatypes -> {
+                        when (what) {
+                            is RegisterExpr -> {
+                                when (what.register) {
+                                    Register.A -> asmgen.out("  asl  a")
+                                    Register.X -> asmgen.out("  txa  |  asl  a |  tax")
+                                    Register.Y -> asmgen.out("  tya  |  asl  a |  tay")
+                                }
+                            }
+                            is IdentifierReference -> asmgen.out("  asl  ${asmgen.asmIdentifierName(what)}")
+                            is DirectMemoryRead -> {
+                                if (what.addressExpression is NumericLiteralValue) {
+                                    val number = (what.addressExpression as NumericLiteralValue).number
+                                    asmgen.out("  asl  ${number.toHex()}")
+                                } else {
+                                    asmgen.translateExpression(what.addressExpression)
+                                    asmgen.out("""
+                    inx
+                    lda  $ESTACK_LO_HEX,x
+                    sta  (+) + 1
+                    lda  $ESTACK_HI_HEX,x
+                    sta  (+) + 2
++                   asl  0            ; modified                    
+                                    """)
+                                }
+                            }
+                            is ArrayIndexedExpression -> {
+                                asmgen.translateExpression(what.identifier)
+                                asmgen.translateExpression(what.arrayspec.index)
+                                asmgen.out("  jsr  prog8_lib.lsl_array_b")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    in WordDatatypes -> {
+                        when (what) {
+                            is ArrayIndexedExpression -> {
+                                asmgen.translateExpression(what.identifier)
+                                asmgen.translateExpression(what.arrayspec.index)
+                                asmgen.out("  jsr  prog8_lib.lsl_array_w")
+                            }
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out(" asl  $variable |  rol  $variable+1")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "lsr" -> {
+                // in-place
+                val what = fcall.args.single()
+                val dt = what.inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.UBYTE -> {
+                        when (what) {
+                            is RegisterExpr -> {
+                                when (what.register) {
+                                    Register.A -> asmgen.out("  lsr  a")
+                                    Register.X -> asmgen.out("  txa  |  lsr  a |  tax")
+                                    Register.Y -> asmgen.out("  tya  |  lsr  a |  tay")
+                                }
+                            }
+                            is IdentifierReference -> asmgen.out("  lsr  ${asmgen.asmIdentifierName(what)}")
+                            is DirectMemoryRead -> {
+                                if (what.addressExpression is NumericLiteralValue) {
+                                    val number = (what.addressExpression as NumericLiteralValue).number
+                                    asmgen.out("  lsr  ${number.toHex()}")
+                                } else {
+                                    asmgen.translateExpression(what.addressExpression)
+                                    asmgen.out("""
+                    inx
+                    lda  $ESTACK_LO_HEX,x
+                    sta  (+) + 1
+                    lda  $ESTACK_HI_HEX,x
+                    sta  (+) + 2
++                   lsr  0            ; modified                    
+                                    """)
+                                }
+                            }
+                            is ArrayIndexedExpression -> {
+                                asmgen.translateExpression(what.identifier)
+                                asmgen.translateExpression(what.arrayspec.index)
+                                asmgen.out("  jsr  prog8_lib.lsr_array_ub")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    DataType.BYTE -> {
+                        when (what) {
+                            is ArrayIndexedExpression -> {
+                                asmgen.translateExpression(what.identifier)
+                                asmgen.translateExpression(what.arrayspec.index)
+                                asmgen.out("  jsr  prog8_lib.lsr_array_b")
+                            }
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out("  lda  $variable |  asl  a |  ror  $variable")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    DataType.UWORD -> {
+                        when (what) {
+                            is ArrayIndexedExpression -> {
+                                asmgen.translateExpression(what.identifier)
+                                asmgen.translateExpression(what.arrayspec.index)
+                                asmgen.out("  jsr  prog8_lib.lsr_array_uw")
+                            }
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out(" lsr  $variable+1 |  ror  $variable")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    DataType.WORD -> {
+                        when (what) {
+                            is ArrayIndexedExpression -> {
+                                asmgen.translateExpression(what.identifier)
+                                asmgen.translateExpression(what.arrayspec.index)
+                                asmgen.out("  jsr  prog8_lib.lsr_array_w")
+                            }
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out("  lda  $variable+1 |  asl a  |  ror  $variable+1 |  ror  $variable")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "rol" -> {
+                // in-place
+                val what = fcall.args.single()
+                val dt = what.inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.UBYTE -> {
+                        when(what) {
+                            is ArrayIndexedExpression -> {
+                                asmgen.translateExpression(what.identifier)
+                                asmgen.translateExpression(what.arrayspec.index)
+                                asmgen.out("  jsr  prog8_lib.rol_array_ub")
+                            }
+                            is DirectMemoryRead -> {
+                                if (what.addressExpression is NumericLiteralValue) {
+                                    val number = (what.addressExpression as NumericLiteralValue).number
+                                    asmgen.out("  rol  ${number.toHex()}")
+                                } else {
+                                    asmgen.translateExpression(what.addressExpression)
+                                    asmgen.out("""
+                    inx
+                    lda  $ESTACK_LO_HEX,x
+                    sta  (+) + 1
+                    lda  $ESTACK_HI_HEX,x
+                    sta  (+) + 2
++                   rol  0            ; modified                    
+                                    """)
+                                }
+                            }
+                            is RegisterExpr -> {
+                                when(what.register) {
+                                    Register.A -> asmgen.out("  rol  a")
+                                    Register.X -> asmgen.out("  txa |  rol  a |  tax")
+                                    Register.Y -> asmgen.out("  tya |  rol  a |  tay")
+                                }
+                            }
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out("  rol  $variable")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    DataType.UWORD -> {
+                        when(what) {
+                            is ArrayIndexedExpression -> {
+                                asmgen.translateExpression(what.identifier)
+                                asmgen.translateExpression(what.arrayspec.index)
+                                asmgen.out("  jsr  prog8_lib.rol_array_uw")
+                            }
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out("  rol  $variable |  rol  $variable+1")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "rol2" -> {
+                // in-place
+                val what = fcall.args.single()
+                val dt = what.inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.UBYTE -> {
+                        when(what) {
+                            is ArrayIndexedExpression -> {
+                                asmgen.translateExpression(what.identifier)
+                                asmgen.translateExpression(what.arrayspec.index)
+                                asmgen.out("  jsr  prog8_lib.rol2_array_ub")
+                            }
+                            is DirectMemoryRead -> {
+                                if (what.addressExpression is NumericLiteralValue) {
+                                    val number = (what.addressExpression as NumericLiteralValue).number
+                                    asmgen.out("  lda  ${number.toHex()} |  cmp  #\$80 |  rol  a |  sta  ${number.toHex()}")
+                                } else {
+                                    asmgen.translateExpression(what.addressExpression)
+                                    asmgen.out("  jsr  prog8_lib.rol2_mem_ub")
+                                }
+                            }
+                            is RegisterExpr -> {
+                                when(what.register) {
+                                    Register.A -> asmgen.out("  cmp  #\$80 |  rol  a  ")
+                                    Register.X -> asmgen.out("  txa  |  cmp  #\$80 |  rol  a  |  tax")
+                                    Register.Y -> asmgen.out("  tya  |  cmp  #\$80 |  rol  a  |  tay")
+                                }
+                            }
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out("  lda  $variable |  cmp  #\$80 |  rol  a |  sta  $variable")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    DataType.UWORD -> {
+                        when(what) {
+                            is ArrayIndexedExpression -> {
+                                asmgen.translateExpression(what.identifier)
+                                asmgen.translateExpression(what.arrayspec.index)
+                                asmgen.out("  jsr  prog8_lib.rol2_array_uw")
+                            }
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out("  asl  $variable |  rol  $variable+1 |  bcc  + |  inc  $variable |+  ")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "ror" -> {
+                // in-place
+                val what = fcall.args.single()
+                val dt = what.inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.UBYTE -> {
+                        when(what) {
+                            is ArrayIndexedExpression -> {
+                                asmgen.translateExpression(what.identifier)
+                                asmgen.translateExpression(what.arrayspec.index)
+                                asmgen.out("  jsr  prog8_lib.ror_array_ub")
+                            }
+                            is DirectMemoryRead -> {
+                                if (what.addressExpression is NumericLiteralValue) {
+                                    val number = (what.addressExpression as NumericLiteralValue).number
+                                    asmgen.out("  ror  ${number.toHex()}")
+                                } else {
+                                    asmgen.translateExpression(what.addressExpression)
+                                    asmgen.out("""
+                    inx
+                    lda  $ESTACK_LO_HEX,x
+                    sta  (+) + 1
+                    lda  $ESTACK_HI_HEX,x
+                    sta  (+) + 2
++                   ror  0            ; modified                    
+                                    """)                                }
+                            }
+                            is RegisterExpr -> {
+                                when(what.register) {
+                                    Register.A -> asmgen.out("  ror  a")
+                                    Register.X -> asmgen.out("  txa |  ror  a |  tax")
+                                    Register.Y -> asmgen.out("  tya |  ror  a |  tay")
+                                }
+                            }
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out("  ror  $variable")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    DataType.UWORD -> {
+                        when(what) {
+                            is ArrayIndexedExpression -> {
+                                asmgen.translateExpression(what.identifier)
+                                asmgen.translateExpression(what.arrayspec.index)
+                                asmgen.out("  jsr  prog8_lib.ror_array_uw")
+                            }
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out("  ror  $variable+1 |  ror  $variable")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "ror2" -> {
+                // in-place
+                val what = fcall.args.single()
+                val dt = what.inferType(program)
+                when (dt.typeOrElse(DataType.STRUCT)) {
+                    DataType.UBYTE -> {
+                        when(what) {
+                            is ArrayIndexedExpression -> {
+                                asmgen.translateExpression(what.identifier)
+                                asmgen.translateExpression(what.arrayspec.index)
+                                asmgen.out("  jsr  prog8_lib.ror2_array_ub")
+                            }
+                            is DirectMemoryRead -> {
+                                if (what.addressExpression is NumericLiteralValue) {
+                                    val number = (what.addressExpression as NumericLiteralValue).number
+                                    asmgen.out("  lda  ${number.toHex()} |  lsr  a |  bcc  + |  ora  #\$80 |+  |  sta  ${number.toHex()}")
+                                } else {
+                                    asmgen.translateExpression(what.addressExpression)
+                                    asmgen.out("  jsr  prog8_lib.ror2_mem_ub")
+                                }
+                            }
+                            is RegisterExpr -> {
+                                when(what.register) {
+                                    Register.A -> asmgen.out("  lsr  a |  bcc  + |  ora  #\$80 |+  ")
+                                    Register.X -> asmgen.out("  txa |  lsr  a |  bcc  + |  ora  #\$80 |+  tax ")
+                                    Register.Y -> asmgen.out("  tya |  lsr  a |  bcc  + |  ora  #\$80 |+  tay ")
+                                }
+                            }
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out("  lda  $variable |  lsr  a |  bcc  + |  ora  #\$80 |+  |  sta  $variable")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    DataType.UWORD -> {
+                        when(what) {
+                            is ArrayIndexedExpression -> {
+                                asmgen.translateExpression(what.identifier)
+                                asmgen.translateExpression(what.arrayspec.index)
+                                asmgen.out("  jsr  prog8_lib.ror2_array_uw")
+                            }
+                            is IdentifierReference -> {
+                                val variable = asmgen.asmIdentifierName(what)
+                                asmgen.out("  lsr  $variable+1 |  ror  $variable |  bcc  + |  lda  $variable+1 |  ora  #\$80 |  sta  $variable+1 |+  ")
+                            }
+                            else -> throw AssemblyError("weird type")
+                        }
+                    }
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "sort" -> {
+                val variable = fcall.args.single()
+                if(variable is IdentifierReference) {
+                    val decl = variable.targetVarDecl(program.namespace)!!
+                    val varName = asmgen.asmIdentifierName(variable)
+                    val numElements = decl.arraysize!!.size()
+                    when(decl.datatype) {
+                        DataType.ARRAY_UB, DataType.ARRAY_B -> {
+                            asmgen.out("""
+                                lda  #<$varName
+                                ldy  #>$varName
+                                sta  ${C64Zeropage.SCRATCH_W1}
+                                sty  ${C64Zeropage.SCRATCH_W1+1}
+                                lda  #$numElements
+                                sta  ${C64Zeropage.SCRATCH_B1}
+                            """)
+                            asmgen.out(if(decl.datatype==DataType.ARRAY_UB) "  jsr  prog8_lib.sort_ub" else "  jsr  prog8_lib.sort_b")
+                        }
+                        DataType.ARRAY_UW, DataType.ARRAY_W -> {
+                            asmgen.out("""
+                                lda  #<$varName
+                                ldy  #>$varName
+                                sta  ${C64Zeropage.SCRATCH_W1}
+                                sty  ${C64Zeropage.SCRATCH_W1+1}
+                                lda  #$numElements
+                                sta  ${C64Zeropage.SCRATCH_B1}
+                            """)
+                            asmgen.out(if(decl.datatype==DataType.ARRAY_UW) "  jsr  prog8_lib.sort_uw" else "  jsr  prog8_lib.sort_w")
+                        }
+                        DataType.ARRAY_F -> TODO("sort floats (consider another solution if possible - this will be very slow, if ever implemented)")
+                        else -> throw AssemblyError("weird type")
+                    }
+                }
+                else
+                    throw AssemblyError("weird type")
+            }
+            "reverse" -> {
+                val variable = fcall.args.single()
+                if (variable is IdentifierReference) {
+                    val decl = variable.targetVarDecl(program.namespace)!!
+                    val varName = asmgen.asmIdentifierName(variable)
+                    val numElements = decl.arraysize!!.size()
+                    when (decl.datatype) {
+                        DataType.ARRAY_UB, DataType.ARRAY_B -> {
+                            asmgen.out("""
+                                lda  #<$varName
+                                ldy  #>$varName
+                                sta  ${C64Zeropage.SCRATCH_W1}
+                                sty  ${C64Zeropage.SCRATCH_W1 + 1}
+                                lda  #$numElements
+                                jsr  prog8_lib.reverse_b
+                            """)
+                        }
+                        DataType.ARRAY_UW, DataType.ARRAY_W -> {
+                            asmgen.out("""
+                                lda  #<$varName
+                                ldy  #>$varName
+                                sta  ${C64Zeropage.SCRATCH_W1}
+                                sty  ${C64Zeropage.SCRATCH_W1 + 1}
+                                lda  #$numElements
+                                jsr  prog8_lib.reverse_w
+                            """)
+                        }
+                        DataType.ARRAY_F -> TODO("reverse floats (consider another solution if possible - this will be quite slow, if ever implemented)")
+                        else -> throw AssemblyError("weird type")
+                    }
+                }
+            }
+            "rsave" -> {
+                // save cpu status flag and all registers A, X, Y.
+                // see http://6502.org/tutorials/register_preservation.html
+                asmgen.out(" php |  sta  ${C64Zeropage.SCRATCH_REG} | pha  | txa  | pha  | tya  | pha  | lda  ${C64Zeropage.SCRATCH_REG}")
+            }
+            "rrestore" -> {
+                // restore all registers and cpu status flag
+                asmgen.out(" pla |  tay |  pla |  tax |  pla |  plp")
+            }
+            else -> {
+                translateFunctionArguments(fcall.args, func)
+                asmgen.out("  jsr  prog8_lib.func_$functionName")
+            }
+        }
+    }
+
+    private fun outputPushAddressAndLenghtOfArray(arg: Expression) {
+        arg as IdentifierReference
+        val identifierName = asmgen.asmIdentifierName(arg)
+        val size = arg.targetVarDecl(program.namespace)!!.arraysize!!.size()!!
+        asmgen.out("""
+                    lda  #<$identifierName
+                    sta  $ESTACK_LO_HEX,x
+                    lda  #>$identifierName
+                    sta  $ESTACK_HI_HEX,x
+                    dex
+                    lda  #$size
+                    sta  $ESTACK_LO_HEX,x
+                    dex
+                    """)
+    }
+
+    private fun outputPushAddressOfIdentifier(arg: Expression) {
+        val identifierName = asmgen.asmIdentifierName(arg as IdentifierReference)
+        asmgen.out("""
+                    lda  #<$identifierName
+                    sta  $ESTACK_LO_HEX,x
+                    lda  #>$identifierName
+                    sta  $ESTACK_HI_HEX,x
+                    dex
+                    """)
+    }
+
+    private fun translateFunctionArguments(args: MutableList<Expression>, signature: FunctionSignature) {
+        args.forEach {
+            asmgen.translateExpression(it)
+        }
+    }
+
+}

compiler/src/prog8/compiler/target/c64/codegen/ExpressionsAsmGen.kt

@@ -0,0 +1,438 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.compiler.toHex
+import prog8.compiler.AssemblyError
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_HI_HEX
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_HI_PLUS1_HEX
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_HEX
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_PLUS1_HEX
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_PLUS2_HEX
+import prog8.functions.BuiltinFunctions
+import kotlin.math.absoluteValue
+
+internal class ExpressionsAsmGen(private val program: Program, private val asmgen: AsmGen) {
+
+    internal fun translateExpression(expression: Expression) {
+        when(expression) {
+            is PrefixExpression -> translateExpression(expression)
+            is BinaryExpression -> translateExpression(expression)
+            is ArrayIndexedExpression -> translatePushFromArray(expression)
+            is TypecastExpression -> translateExpression(expression)
+            is AddressOf -> translateExpression(expression)
+            is DirectMemoryRead -> translateExpression(expression)
+            is NumericLiteralValue -> translateExpression(expression)
+            is RegisterExpr -> translateExpression(expression)
+            is IdentifierReference -> translateExpression(expression)
+            is FunctionCall -> translateExpression(expression)
+            is ArrayLiteralValue, is StringLiteralValue -> TODO("string/array/struct assignment?")
+            is StructLiteralValue -> throw AssemblyError("struct literal value assignment should have been flattened")
+            is RangeExpr -> throw AssemblyError("range expression should have been changed into array values")
+        }
+    }
+
+    private fun translateExpression(expression: FunctionCall) {
+        val functionName = expression.target.nameInSource.last()
+        val builtinFunc = BuiltinFunctions[functionName]
+        if (builtinFunc != null) {
+            asmgen.translateFunctioncallExpression(expression, builtinFunc)
+        } else {
+            asmgen.translateFunctionCall(expression)
+            val sub = expression.target.targetSubroutine(program.namespace)!!
+            val returns = sub.returntypes.zip(sub.asmReturnvaluesRegisters)
+            for ((_, reg) in returns) {
+                if (!reg.stack) {
+                    // result value in cpu or status registers, put it on the stack
+                    if (reg.registerOrPair != null) {
+                        when (reg.registerOrPair) {
+                            RegisterOrPair.A -> asmgen.out("  sta  $ESTACK_LO_HEX,x |  dex")
+                            RegisterOrPair.Y -> asmgen.out("  tya |  sta  $ESTACK_LO_HEX,x |  dex")
+                            RegisterOrPair.AY -> asmgen.out("  sta  $ESTACK_LO_HEX,x |  tya |  sta  $ESTACK_HI_HEX,x |  dex")
+                            RegisterOrPair.X, RegisterOrPair.AX, RegisterOrPair.XY -> throw AssemblyError("can't push X register - use a variable")
+                        }
+                    }
+                    // return value from a statusregister is not put on the stack, it should be acted on via a conditional branch such as if_cc
+                }
+            }
+        }
+    }
+
+    private fun translateExpression(expr: TypecastExpression) {
+        translateExpression(expr.expression)
+        when(expr.expression.inferType(program).typeOrElse(DataType.STRUCT)) {
+            DataType.UBYTE -> {
+                when(expr.type) {
+                    DataType.UBYTE, DataType.BYTE -> {}
+                    DataType.UWORD, DataType.WORD -> asmgen.out("  lda  #0  |  sta  $ESTACK_HI_PLUS1_HEX,x")
+                    DataType.FLOAT -> asmgen.out(" jsr  c64flt.stack_ub2float")
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            DataType.BYTE -> {
+                when(expr.type) {
+                    DataType.UBYTE, DataType.BYTE -> {}
+                    DataType.UWORD, DataType.WORD -> asmgen.out("  lda  $ESTACK_LO_PLUS1_HEX,x  |  ${asmgen.signExtendAtoMsb("$ESTACK_HI_PLUS1_HEX,x")}")
+                    DataType.FLOAT -> asmgen.out(" jsr  c64flt.stack_b2float")
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            DataType.UWORD -> {
+                when(expr.type) {
+                    DataType.BYTE, DataType.UBYTE -> {}
+                    DataType.WORD, DataType.UWORD -> {}
+                    DataType.FLOAT -> asmgen.out(" jsr  c64flt.stack_uw2float")
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            DataType.WORD -> {
+                when(expr.type) {
+                    DataType.BYTE, DataType.UBYTE -> {}
+                    DataType.WORD, DataType.UWORD -> {}
+                    DataType.FLOAT -> asmgen.out(" jsr  c64flt.stack_w2float")
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            DataType.FLOAT -> {
+                when(expr.type) {
+                    DataType.UBYTE -> asmgen.out(" jsr  c64flt.stack_float2uw")
+                    DataType.BYTE -> asmgen.out(" jsr  c64flt.stack_float2w")
+                    DataType.UWORD -> asmgen.out(" jsr  c64flt.stack_float2uw")
+                    DataType.WORD -> asmgen.out(" jsr  c64flt.stack_float2w")
+                    DataType.FLOAT -> {}
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            in PassByReferenceDatatypes -> throw AssemblyError("cannot case a pass-by-reference datatypes into something else")
+            else -> throw AssemblyError("weird type")
+        }
+    }
+
+    private fun translateExpression(expr: AddressOf) {
+        val name = asmgen.asmIdentifierName(expr.identifier)
+        asmgen.out("  lda  #<$name |  sta  $ESTACK_LO_HEX,x |  lda  #>$name  |  sta  $ESTACK_HI_HEX,x  | dex")
+    }
+
+    private fun translateExpression(expr: DirectMemoryRead) {
+        when(expr.addressExpression) {
+            is NumericLiteralValue -> {
+                val address = (expr.addressExpression as NumericLiteralValue).number.toInt()
+                asmgen.out("  lda  ${address.toHex()} |  sta  $ESTACK_LO_HEX,x |  dex")
+            }
+            is IdentifierReference -> {
+                val sourceName = asmgen.asmIdentifierName(expr.addressExpression as IdentifierReference)
+                asmgen.out("  lda  $sourceName |  sta  $ESTACK_LO_HEX,x |  dex")
+            }
+            else -> {
+                translateExpression(expr.addressExpression)
+                asmgen.out("  jsr  prog8_lib.read_byte_from_address")
+                asmgen.out("  sta  $ESTACK_LO_PLUS1_HEX,x")
+            }
+        }
+    }
+
+    private fun translateExpression(expr: NumericLiteralValue) {
+        when(expr.type) {
+            DataType.UBYTE, DataType.BYTE -> asmgen.out(" lda  #${expr.number.toHex()}  | sta  $ESTACK_LO_HEX,x  | dex")
+            DataType.UWORD, DataType.WORD -> asmgen.out("""
+                lda  #<${expr.number.toHex()}
+                sta  $ESTACK_LO_HEX,x
+                lda  #>${expr.number.toHex()}
+                sta  $ESTACK_HI_HEX,x
+                dex
+            """)
+            DataType.FLOAT -> {
+                val floatConst = asmgen.getFloatConst(expr.number.toDouble())
+                asmgen.out(" lda  #<$floatConst |  ldy  #>$floatConst |  jsr  c64flt.push_float")
+            }
+            else -> throw AssemblyError("weird type")
+        }
+    }
+
+    private fun translateExpression(expr: RegisterExpr) {
+        when(expr.register) {
+            Register.A -> asmgen.out(" sta  $ESTACK_LO_HEX,x | dex")
+            Register.X -> throw AssemblyError("cannot push X - use a variable instead of the X register")
+            Register.Y -> asmgen.out(" tya |  sta  $ESTACK_LO_HEX,x | dex")
+        }
+    }
+
+    private fun translateExpression(expr: IdentifierReference) {
+        val varname = asmgen.asmIdentifierName(expr)
+        when(expr.inferType(program).typeOrElse(DataType.STRUCT)) {
+            DataType.UBYTE, DataType.BYTE -> {
+                asmgen.out("  lda  $varname  |  sta  $ESTACK_LO_HEX,x  |  dex")
+            }
+            DataType.UWORD, DataType.WORD -> {
+                asmgen.out("  lda  $varname  |  sta  $ESTACK_LO_HEX,x  |  lda  $varname+1 |  sta  $ESTACK_HI_HEX,x |  dex")
+            }
+            DataType.FLOAT -> {
+                asmgen.out(" lda  #<$varname |  ldy  #>$varname|  jsr  c64flt.push_float")
+            }
+            in IterableDatatypes -> {
+                asmgen.out("  lda  #<$varname  |  sta  $ESTACK_LO_HEX,x  |  lda  #>$varname |  sta  $ESTACK_HI_HEX,x |  dex")
+            }
+            else -> throw AssemblyError("stack push weird variable type $expr")
+        }
+    }
+
+    private val optimizedByteMultiplications = setOf(3,5,6,7,9,10,11,12,13,14,15,20,25,40)
+    private val optimizedWordMultiplications = setOf(3,5,6,7,9,10,12,15,20,25,40)
+    private val powersOfTwo = setOf(0,1,2,4,8,16,32,64,128,256)
+
+    private fun translateExpression(expr: BinaryExpression) {
+        val leftIDt = expr.left.inferType(program)
+        val rightIDt = expr.right.inferType(program)
+        if(!leftIDt.isKnown || !rightIDt.isKnown)
+            throw AssemblyError("can't infer type of both expression operands")
+
+        val leftDt = leftIDt.typeOrElse(DataType.STRUCT)
+        val rightDt = rightIDt.typeOrElse(DataType.STRUCT)
+        // see if we can apply some optimized routines
+        when(expr.operator) {
+            ">>" -> {
+                // bit-shifts are always by a constant number (for now)
+                translateExpression(expr.left)
+                val amount = expr.right.constValue(program)!!.number.toInt()
+                when (leftDt) {
+                    DataType.UBYTE -> repeat(amount) { asmgen.out("  lsr  $ESTACK_LO_PLUS1_HEX,x") }
+                    DataType.BYTE -> repeat(amount) { asmgen.out("  lda  $ESTACK_LO_PLUS1_HEX,x |  asl  a |  ror  $ESTACK_LO_PLUS1_HEX,x") }
+                    DataType.UWORD -> repeat(amount) { asmgen.out("  lsr  $ESTACK_HI_PLUS1_HEX,x |  ror  $ESTACK_LO_PLUS1_HEX,x") }
+                    DataType.WORD -> repeat(amount) { asmgen.out("  lda  $ESTACK_HI_PLUS1_HEX,x |  asl a  |  ror  $ESTACK_HI_PLUS1_HEX,x |  ror  $ESTACK_LO_PLUS1_HEX,x") }
+                    else -> throw AssemblyError("weird type")
+                }
+                return
+            }
+            "<<" -> {
+                // bit-shifts are always by a constant number (for now)
+                translateExpression(expr.left)
+                val amount = expr.right.constValue(program)!!.number.toInt()
+                if (leftDt in ByteDatatypes)
+                    repeat(amount) { asmgen.out("  asl  $ESTACK_LO_PLUS1_HEX,x") }
+                else
+                    repeat(amount) { asmgen.out("  asl  $ESTACK_LO_PLUS1_HEX,x |  rol  $ESTACK_HI_PLUS1_HEX,x") }
+                return
+            }
+            "*" -> {
+                val value = expr.right.constValue(program)
+                if(value!=null) {
+                    if(rightDt in IntegerDatatypes) {
+                        val amount = value.number.toInt()
+                        if(amount in powersOfTwo)
+                            printWarning("${expr.right.position} multiplication by power of 2 should have been optimized into a left shift instruction: $amount")
+                        when(rightDt) {
+                            DataType.UBYTE -> {
+                                if(amount in optimizedByteMultiplications) {
+                                    translateExpression(expr.left)
+                                    asmgen.out(" jsr  math.mul_byte_$amount")
+                                    return
+                                }
+                            }
+                            DataType.BYTE -> {
+                                if(amount in optimizedByteMultiplications) {
+                                    translateExpression(expr.left)
+                                    asmgen.out(" jsr  math.mul_byte_$amount")
+                                    return
+                                }
+                                if(amount.absoluteValue in optimizedByteMultiplications) {
+                                    translateExpression(expr.left)
+                                    asmgen.out(" jsr  prog8_lib.neg_b |  jsr  math.mul_byte_${amount.absoluteValue}")
+                                    return
+                                }
+                            }
+                            DataType.UWORD -> {
+                                if(amount in optimizedWordMultiplications) {
+                                    translateExpression(expr.left)
+                                    asmgen.out(" jsr  math.mul_word_$amount")
+                                    return
+                                }
+                            }
+                            DataType.WORD -> {
+                                if(amount in optimizedWordMultiplications) {
+                                    translateExpression(expr.left)
+                                    asmgen.out(" jsr  math.mul_word_$amount")
+                                    return
+                                }
+                                if(amount.absoluteValue in optimizedWordMultiplications) {
+                                    translateExpression(expr.left)
+                                    asmgen.out(" jsr  prog8_lib.neg_w |  jsr  math.mul_word_${amount.absoluteValue}")
+                                    return
+                                }
+                            }
+                            else -> {}
+                        }
+                    }
+                }
+            }
+        }
+
+        // the general, non-optimized cases
+        translateExpression(expr.left)
+        translateExpression(expr.right)
+        if(leftDt!=rightDt)
+            throw AssemblyError("binary operator ${expr.operator} left/right dt not identical")     // is this strictly required always?
+        when (leftDt) {
+            in ByteDatatypes -> translateBinaryOperatorBytes(expr.operator, leftDt)
+            in WordDatatypes -> translateBinaryOperatorWords(expr.operator, leftDt)
+            DataType.FLOAT -> translateBinaryOperatorFloats(expr.operator)
+            else -> throw AssemblyError("non-numerical datatype")
+        }
+    }
+
+    private fun translateExpression(expr: PrefixExpression) {
+        translateExpression(expr.expression)
+        val type = expr.inferType(program).typeOrElse(DataType.STRUCT)
+        when(expr.operator) {
+            "+" -> {}
+            "-" -> {
+                when(type) {
+                    in ByteDatatypes -> asmgen.out("  jsr  prog8_lib.neg_b")
+                    in WordDatatypes -> asmgen.out("  jsr  prog8_lib.neg_w")
+                    DataType.FLOAT -> asmgen.out("  jsr  c64flt.neg_f")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "~" -> {
+                when(type) {
+                    in ByteDatatypes ->
+                        asmgen.out("""
+                            lda  $ESTACK_LO_PLUS1_HEX,x
+                            eor  #255
+                            sta  $ESTACK_LO_PLUS1_HEX,x
+                            """)
+                    in WordDatatypes -> asmgen.out("  jsr  prog8_lib.inv_word")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "not" -> {
+                when(type) {
+                    in ByteDatatypes -> asmgen.out("  jsr  prog8_lib.not_byte")
+                    in WordDatatypes -> asmgen.out("  jsr  prog8_lib.not_word")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            else -> throw AssemblyError("invalid prefix operator ${expr.operator}")
+        }
+    }
+
+    private fun translatePushFromArray(arrayExpr: ArrayIndexedExpression) {
+        // assume *reading* from an array
+        val index = arrayExpr.arrayspec.index
+        val arrayDt = arrayExpr.identifier.targetVarDecl(program.namespace)!!.datatype
+        val arrayVarName = asmgen.asmIdentifierName(arrayExpr.identifier)
+        if(index is NumericLiteralValue) {
+            val elementDt = ArrayElementTypes.getValue(arrayDt)
+            val indexValue = index.number.toInt() * elementDt.memorySize()
+            when(elementDt) {
+                in ByteDatatypes -> {
+                    asmgen.out("  lda  $arrayVarName+$indexValue |  sta  $ESTACK_LO_HEX,x |  dex")
+                }
+                in WordDatatypes -> {
+                    asmgen.out("  lda  $arrayVarName+$indexValue |  sta  $ESTACK_LO_HEX,x |  lda  $arrayVarName+$indexValue+1 |  sta  $ESTACK_HI_HEX,x |  dex")
+                }
+                DataType.FLOAT -> {
+                    asmgen.out("  lda  #<$arrayVarName+$indexValue |  ldy  #>$arrayVarName+$indexValue |  jsr  c64flt.push_float")
+                }
+                else -> throw AssemblyError("weird type")
+            }
+        } else {
+            asmgen.translateArrayIndexIntoA(arrayExpr)
+            asmgen.readAndPushArrayvalueWithIndexA(arrayDt, arrayExpr.identifier)
+        }
+    }
+
+    private fun translateBinaryOperatorBytes(operator: String, types: DataType) {
+        when(operator) {
+            "**" -> throw AssemblyError("** operator requires floats")
+            "*" -> asmgen.out("  jsr  prog8_lib.mul_byte")  //  the optimized routines should have been checked earlier
+            "/" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.idiv_ub" else "  jsr  prog8_lib.idiv_b")
+            "%" -> {
+                if(types==DataType.BYTE)
+                    throw AssemblyError("remainder of signed integers is not properly defined/implemented, use unsigned instead")
+                asmgen.out("  jsr prog8_lib.remainder_ub")
+            }
+            "+" -> asmgen.out("""
+                lda  $ESTACK_LO_PLUS2_HEX,x
+                clc
+                adc  $ESTACK_LO_PLUS1_HEX,x
+                inx
+                sta  $ESTACK_LO_PLUS1_HEX,x
+                """)
+            "-" -> asmgen.out("""
+                lda  $ESTACK_LO_PLUS2_HEX,x
+                sec
+                sbc  $ESTACK_LO_PLUS1_HEX,x
+                inx
+                sta  $ESTACK_LO_PLUS1_HEX,x
+                """)
+            "<<", ">>" -> throw AssemblyError("bit-shifts not via stack")
+            "<" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.less_ub" else "  jsr  prog8_lib.less_b")
+            ">" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.greater_ub" else "  jsr  prog8_lib.greater_b")
+            "<=" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.lesseq_ub" else "  jsr  prog8_lib.lesseq_b")
+            ">=" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.greatereq_ub" else "  jsr  prog8_lib.greatereq_b")
+            "==" -> asmgen.out("  jsr  prog8_lib.equal_b")
+            "!=" -> asmgen.out("  jsr  prog8_lib.notequal_b")
+            "&" -> asmgen.out("  jsr  prog8_lib.bitand_b")
+            "^" -> asmgen.out("  jsr  prog8_lib.bitxor_b")
+            "|" -> asmgen.out("  jsr  prog8_lib.bitor_b")
+            "and" -> asmgen.out("  jsr  prog8_lib.and_b")
+            "or" -> asmgen.out("  jsr  prog8_lib.or_b")
+            "xor" -> asmgen.out("  jsr  prog8_lib.xor_b")
+            else -> throw AssemblyError("invalid operator $operator")
+        }
+    }
+
+    private fun translateBinaryOperatorWords(operator: String, types: DataType) {
+        when(operator) {
+            "**" -> throw AssemblyError("** operator requires floats")
+            "*" -> asmgen.out("  jsr  prog8_lib.mul_word")
+            "/" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.idiv_uw" else "  jsr  prog8_lib.idiv_w")
+            "%" -> {
+                if(types==DataType.WORD)
+                    throw AssemblyError("remainder of signed integers is not properly defined/implemented, use unsigned instead")
+                asmgen.out("  jsr prog8_lib.remainder_uw")
+            }
+            "+" -> asmgen.out("  jsr  prog8_lib.add_w")
+            "-" -> asmgen.out("  jsr  prog8_lib.sub_w")
+            "<<" -> throw AssemblyError("<< should not operate via stack")
+            ">>" -> throw AssemblyError(">> should not operate via stack")
+            "<" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.less_uw" else "  jsr  prog8_lib.less_w")
+            ">" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.greater_uw" else "  jsr  prog8_lib.greater_w")
+            "<=" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.lesseq_uw" else "  jsr  prog8_lib.lesseq_w")
+            ">=" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.greatereq_uw" else "  jsr  prog8_lib.greatereq_w")
+            "==" -> asmgen.out("  jsr  prog8_lib.equal_w")
+            "!=" -> asmgen.out("  jsr  prog8_lib.notequal_w")
+            "&" -> asmgen.out("  jsr  prog8_lib.bitand_w")
+            "^" -> asmgen.out("  jsr  prog8_lib.bitxor_w")
+            "|" -> asmgen.out("  jsr  prog8_lib.bitor_w")
+            "and" -> asmgen.out("  jsr  prog8_lib.and_w")
+            "or" -> asmgen.out("  jsr  prog8_lib.or_w")
+            "xor" -> asmgen.out("  jsr  prog8_lib.xor_w")
+            else -> throw AssemblyError("invalid operator $operator")
+        }
+    }
+
+    private fun translateBinaryOperatorFloats(operator: String) {
+        when(operator) {
+            "**" -> asmgen.out(" jsr  c64flt.pow_f")
+            "*" -> asmgen.out("  jsr  c64flt.mul_f")
+            "/" -> asmgen.out("  jsr  c64flt.div_f")
+            "+" -> asmgen.out("  jsr  c64flt.add_f")
+            "-" -> asmgen.out("  jsr  c64flt.sub_f")
+            "<" -> asmgen.out("  jsr  c64flt.less_f")
+            ">" -> asmgen.out("  jsr  c64flt.greater_f")
+            "<=" -> asmgen.out("  jsr  c64flt.lesseq_f")
+            ">=" -> asmgen.out("  jsr  c64flt.greatereq_f")
+            "==" -> asmgen.out("  jsr  c64flt.equal_f")
+            "!=" -> asmgen.out("  jsr  c64flt.notequal_f")
+            "%", "<<", ">>", "&", "^", "|", "and", "or", "xor" -> throw AssemblyError("requires integer datatype")
+            else -> throw AssemblyError("invalid operator $operator")
+        }
+    }
+}

compiler/src/prog8/compiler/target/c64/codegen/ForLoopsAsmGen.kt

@@ -0,0 +1,700 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.Program
+import prog8.ast.base.DataType
+import prog8.ast.base.Register
+import prog8.ast.expressions.IdentifierReference
+import prog8.ast.expressions.RangeExpr
+import prog8.ast.statements.AssignTarget
+import prog8.ast.statements.Assignment
+import prog8.ast.statements.ForLoop
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_HEX
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_PLUS1_HEX
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_HI_PLUS1_HEX
+import prog8.compiler.toHex
+import prog8.compiler.AssemblyError
+import kotlin.math.absoluteValue
+
+// todo choose more efficient comparisons to avoid needless lda's
+// todo optimize common case step == 2 / -2
+
+
+internal class ForLoopsAsmGen(private val program: Program, private val asmgen: AsmGen) {
+
+    internal fun translate(stmt: ForLoop) {
+        val iterableDt = stmt.iterable.inferType(program)
+        if(!iterableDt.isKnown)
+            throw AssemblyError("can't determine iterable dt")
+        when(stmt.iterable) {
+            is RangeExpr -> {
+                val range = (stmt.iterable as RangeExpr).toConstantIntegerRange()
+                if(range==null) {
+                    translateForOverNonconstRange(stmt, iterableDt.typeOrElse(DataType.STRUCT), stmt.iterable as RangeExpr)
+                } else {
+                    translateForOverConstRange(stmt, iterableDt.typeOrElse(DataType.STRUCT), range)
+                }
+            }
+            is IdentifierReference -> {
+                translateForOverIterableVar(stmt, iterableDt.typeOrElse(DataType.STRUCT), stmt.iterable as IdentifierReference)
+            }
+            else -> throw AssemblyError("can't iterate over ${stmt.iterable}")
+        }
+    }
+
+    private fun translateForOverNonconstRange(stmt: ForLoop, iterableDt: DataType, range: RangeExpr) {
+        val loopLabel = asmgen.makeLabel("for_loop")
+        val endLabel = asmgen.makeLabel("for_end")
+        val continueLabel = asmgen.makeLabel("for_continue")
+        asmgen.loopEndLabels.push(endLabel)
+        asmgen.loopContinueLabels.push(continueLabel)
+        val stepsize=range.step.constValue(program)!!.number.toInt()
+        when(iterableDt) {
+            DataType.ARRAY_B, DataType.ARRAY_UB -> {
+                if (stepsize==1 || stepsize==-1) {
+
+                    // bytes, step 1 or -1
+
+                    val incdec = if(stepsize==1) "inc" else "dec"
+                    if (stmt.loopRegister != null) {
+                        // loop register over range
+                        if(stmt.loopRegister!= Register.A)
+                            throw AssemblyError("can only use A")
+                        asmgen.translateExpression(range.to)
+                        asmgen.translateExpression(range.from)
+                        asmgen.out("""
+                inx
+                lda  ${ESTACK_LO_HEX},x
+                sta  $loopLabel+1
+$loopLabel      lda  #0                 ; modified""")
+                        asmgen.translate(stmt.body)
+                        asmgen.out("""
+$continueLabel  lda  $loopLabel+1
+                cmp  $ESTACK_LO_PLUS1_HEX,x
+                beq  $endLabel
+                $incdec  $loopLabel+1
+                jmp  $loopLabel
+$endLabel       inx""")
+                    } else {
+                        // loop over byte range via loopvar
+                        val varname = asmgen.asmIdentifierName(stmt.loopVar!!)
+                        asmgen.translateExpression(range.to)
+                        asmgen.translateExpression(range.from)
+                        asmgen.out("""
+                inx
+                lda  ${ESTACK_LO_HEX},x
+                sta  $varname
+$loopLabel""")
+                        asmgen.translate(stmt.body)
+                        asmgen.out("""
+$continueLabel  lda  $varname
+                cmp  $ESTACK_LO_PLUS1_HEX,x
+                beq  $endLabel
+                $incdec  $varname
+                jmp  $loopLabel
+$endLabel       inx""")
+                    }
+                }
+                else {
+
+                    // bytes, step >= 2 or <= -2
+
+                    if (stmt.loopRegister != null) {
+                        // loop register over range
+                        if(stmt.loopRegister!= Register.A)
+                            throw AssemblyError("can only use A")
+                        asmgen.translateExpression(range.to)
+                        asmgen.translateExpression(range.from)
+                        asmgen.out("""
+                inx
+                lda  ${ESTACK_LO_HEX},x
+                sta  $loopLabel+1
+$loopLabel      lda  #0                 ; modified""")
+                        asmgen.translate(stmt.body)
+                        asmgen.out("""
+$continueLabel  lda  $loopLabel+1""")
+                        if(stepsize>0) {
+                            asmgen.out("""
+                clc
+                adc  #$stepsize
+                sta  $loopLabel+1
+                cmp  $ESTACK_LO_PLUS1_HEX,x
+                bcc  $loopLabel
+                beq  $loopLabel""")
+                        } else {
+                            asmgen.out("""
+                sec
+                sbc  #${stepsize.absoluteValue}
+                sta  $loopLabel+1
+                cmp  $ESTACK_LO_PLUS1_HEX,x
+                bcs  $loopLabel""")
+                        }
+                        asmgen.out("""
+$endLabel       inx""")
+                    } else {
+                        // loop over byte range via loopvar
+                        val varname = asmgen.asmIdentifierName(stmt.loopVar!!)
+                        asmgen.translateExpression(range.to)
+                        asmgen.translateExpression(range.from)
+                        asmgen.out("""
+                inx
+                lda  ${ESTACK_LO_HEX},x
+                sta  $varname
+$loopLabel""")
+                        asmgen.translate(stmt.body)
+                        asmgen.out("""
+$continueLabel  lda  $varname""")
+                        if(stepsize>0) {
+                            asmgen.out("""
+                clc
+                adc  #$stepsize
+                sta  $varname
+                cmp  $ESTACK_LO_PLUS1_HEX,x
+                bcc  $loopLabel
+                beq  $loopLabel""")
+                        } else {
+                            asmgen.out("""
+                sec
+                sbc  #${stepsize.absoluteValue}
+                sta  $varname
+                cmp  $ESTACK_LO_PLUS1_HEX,x
+                bcs  $loopLabel""")
+                        }
+                        asmgen.out("""
+$endLabel       inx""")
+                    }
+                }
+            }
+            DataType.ARRAY_W, DataType.ARRAY_UW -> {
+                when {
+
+                    // words, step 1 or -1
+
+                    stepsize == 1 || stepsize == -1 -> {
+                        asmgen.translateExpression(range.to)
+                        val varname = asmgen.asmIdentifierName(stmt.loopVar!!)
+                        val assignLoopvar = Assignment(AssignTarget(null, stmt.loopVar, null, null, stmt.loopVar!!.position),
+                                null, range.from, range.position)
+                        assignLoopvar.linkParents(stmt)
+                        asmgen.translate(assignLoopvar)
+                        asmgen.out(loopLabel)
+                        asmgen.translate(stmt.body)
+                        asmgen.out("""
+                lda  $varname+1
+                cmp  $ESTACK_HI_PLUS1_HEX,x
+                bne  +
+                lda  $varname
+                cmp  $ESTACK_LO_PLUS1_HEX,x
+                beq  $endLabel""")
+                        if(stepsize==1) {
+                            asmgen.out("""
++               inc  $varname
+                bne  +
+                inc  $varname+1            
+                            """)
+                        } else {
+                            asmgen.out("""
++               lda  $varname
+                bne  +
+                dec  $varname+1
++               dec  $varname""")
+                        }
+                        asmgen.out("""
++               jmp  $loopLabel
+$endLabel       inx""")
+                    }
+                    stepsize > 0 -> {
+
+                        // (u)words, step >= 2
+
+                        asmgen.translateExpression(range.to)
+                        val varname = asmgen.asmIdentifierName(stmt.loopVar!!)
+                        val assignLoopvar = Assignment(AssignTarget(null, stmt.loopVar, null, null, stmt.loopVar!!.position),
+                                null, range.from, range.position)
+                        assignLoopvar.linkParents(stmt)
+                        asmgen.translate(assignLoopvar)
+                        asmgen.out(loopLabel)
+                        asmgen.translate(stmt.body)
+
+                        if (iterableDt == DataType.ARRAY_UW) {
+                            asmgen.out("""
+                lda  $varname
+                clc
+                adc  #<$stepsize
+                sta  $varname
+                lda  $varname+1
+                adc  #>$stepsize
+                sta  $varname+1
+                lda  $ESTACK_HI_PLUS1_HEX,x
+                cmp  $varname+1
+                bcc  $endLabel
+                bne  $loopLabel
+                lda  $varname
+                cmp  $ESTACK_LO_PLUS1_HEX,x
+                bcc  $endLabel
+                bcs  $loopLabel
+$endLabel       inx""")
+                        } else {
+                            asmgen.out("""
+                lda  $varname
+                clc
+                adc  #<$stepsize
+                sta  $varname
+                lda  $varname+1
+                adc  #>$stepsize
+                sta  $varname+1
+                lda  $ESTACK_LO_PLUS1_HEX,x
+                cmp  $varname
+                lda  $ESTACK_HI_PLUS1_HEX,x
+                sbc  $varname+1
+                bvc  +
+                eor  #$80
++               bpl  $loopLabel                
+$endLabel       inx""")
+                        }
+                    }
+                    else -> {
+
+                        // (u)words, step <= -2
+                        asmgen.translateExpression(range.to)
+                        val varname = asmgen.asmIdentifierName(stmt.loopVar!!)
+                        val assignLoopvar = Assignment(AssignTarget(null, stmt.loopVar, null, null, stmt.loopVar!!.position),
+                                null, range.from, range.position)
+                        assignLoopvar.linkParents(stmt)
+                        asmgen.translate(assignLoopvar)
+                        asmgen.out(loopLabel)
+                        asmgen.translate(stmt.body)
+
+                        if(iterableDt==DataType.ARRAY_UW) {
+                            asmgen.out("""
+                lda  $varname
+                sec
+                sbc  #<${stepsize.absoluteValue}
+                sta  $varname
+                lda  $varname+1
+                sbc  #>${stepsize.absoluteValue}
+                sta  $varname+1
+                cmp  $ESTACK_HI_PLUS1_HEX,x
+                bcc  $endLabel
+                bne  $loopLabel
+                lda  $varname
+                cmp  $ESTACK_LO_PLUS1_HEX,x
+                bcs  $loopLabel
+$endLabel       inx""")
+                        } else {
+                            asmgen.out("""
+                lda  $varname
+                sec
+                sbc  #<${stepsize.absoluteValue}
+                sta  $varname
+                pha
+                lda  $varname+1
+                sbc  #>${stepsize.absoluteValue}
+                sta  $varname+1
+                pla
+                cmp  $ESTACK_LO_PLUS1_HEX,x
+                lda  $varname+1
+                sbc  $ESTACK_HI_PLUS1_HEX,x
+                bvc  +
+                eor  #$80
++               bpl  $loopLabel                
+$endLabel       inx""")
+                        }
+                    }
+                }
+            }
+            else -> throw AssemblyError("range expression can only be byte or word")
+        }
+
+        asmgen.loopEndLabels.pop()
+        asmgen.loopContinueLabels.pop()
+    }
+
+    private fun translateForOverIterableVar(stmt: ForLoop, iterableDt: DataType, ident: IdentifierReference) {
+        val loopLabel = asmgen.makeLabel("for_loop")
+        val endLabel = asmgen.makeLabel("for_end")
+        val continueLabel = asmgen.makeLabel("for_continue")
+        asmgen.loopEndLabels.push(endLabel)
+        asmgen.loopContinueLabels.push(continueLabel)
+        val iterableName = asmgen.asmIdentifierName(ident)
+        val decl = ident.targetVarDecl(program.namespace)!!
+        when(iterableDt) {
+            DataType.STR -> {
+                if(stmt.loopRegister!=null && stmt.loopRegister!= Register.A)
+                    throw AssemblyError("can only use A")
+                asmgen.out("""
+                    lda  #<$iterableName
+                    ldy  #>$iterableName
+                    sta  $loopLabel+1
+                    sty  $loopLabel+2
+$loopLabel          lda  ${65535.toHex()}       ; modified
+                    beq  $endLabel""")
+                if(stmt.loopVar!=null)
+                    asmgen.out("  sta  ${asmgen.asmIdentifierName(stmt.loopVar!!)}")
+                asmgen.translate(stmt.body)
+                asmgen.out("""
+$continueLabel      inc  $loopLabel+1
+                    bne  $loopLabel
+                    inc  $loopLabel+2
+                    bne  $loopLabel
+$endLabel""")
+            }
+            DataType.ARRAY_UB, DataType.ARRAY_B -> {
+                // TODO: optimize loop code when the length of the array is < 256, don't need a separate counter in such cases
+                val length = decl.arraysize!!.size()!!
+                if(stmt.loopRegister!=null && stmt.loopRegister!= Register.A)
+                    throw AssemblyError("can only use A")
+                val counterLabel = asmgen.makeLabel("for_counter")
+                val modifiedLabel = asmgen.makeLabel("for_modified")
+                asmgen.out("""
+                    lda  #<$iterableName
+                    ldy  #>$iterableName
+                    sta  $modifiedLabel+1
+                    sty  $modifiedLabel+2
+                    ldy  #0
+$loopLabel          sty  $counterLabel
+$modifiedLabel      lda  ${65535.toHex()},y       ; modified""")
+                if(stmt.loopVar!=null)
+                    asmgen.out("  sta  ${asmgen.asmIdentifierName(stmt.loopVar!!)}")
+                asmgen.translate(stmt.body)
+                asmgen.out("""
+$continueLabel      ldy  $counterLabel
+                    iny
+                    cpy  #${length and 255}
+                    beq  $endLabel
+                    jmp  $loopLabel
+$counterLabel       .byte  0
+$endLabel""")
+            }
+            DataType.ARRAY_W, DataType.ARRAY_UW -> {
+                // TODO: optimize loop code when the length of the array is < 256, don't need a separate counter in such cases
+                val length = decl.arraysize!!.size()!! * 2
+                if(stmt.loopRegister!=null)
+                    throw AssemblyError("can't use register to loop over words")
+                val counterLabel = asmgen.makeLabel("for_counter")
+                val modifiedLabel = asmgen.makeLabel("for_modified")
+                val modifiedLabel2 = asmgen.makeLabel("for_modified2")
+                val loopvarName = asmgen.asmIdentifierName(stmt.loopVar!!)
+                asmgen.out("""
+                    lda  #<$iterableName
+                    ldy  #>$iterableName
+                    sta  $modifiedLabel+1
+                    sty  $modifiedLabel+2
+                    lda  #<$iterableName+1
+                    ldy  #>$iterableName+1
+                    sta  $modifiedLabel2+1
+                    sty  $modifiedLabel2+2
+                    ldy  #0
+$loopLabel          sty  $counterLabel
+$modifiedLabel      lda  ${65535.toHex()},y       ; modified
+                    sta  $loopvarName
+$modifiedLabel2     lda  ${65535.toHex()},y       ; modified
+                    sta  $loopvarName+1""")
+                asmgen.translate(stmt.body)
+                asmgen.out("""
+$continueLabel      ldy  $counterLabel
+                    iny
+                    iny
+                    cpy  #${length and 255}
+                    beq  $endLabel
+                    jmp  $loopLabel
+$counterLabel       .byte  0
+$endLabel""")
+            }
+            DataType.ARRAY_F -> {
+                throw AssemblyError("for loop with floating point variables is not supported")
+            }
+            else -> throw AssemblyError("can't iterate over $iterableDt")
+        }
+        asmgen.loopEndLabels.pop()
+        asmgen.loopContinueLabels.pop()
+    }
+
+    private fun translateForOverConstRange(stmt: ForLoop, iterableDt: DataType, range: IntProgression) {
+        // TODO: optimize loop code when the range is < 256 iterations, don't need a separate counter in such cases
+        if (range.isEmpty())
+            throw AssemblyError("empty range")
+        val loopLabel = asmgen.makeLabel("for_loop")
+        val endLabel = asmgen.makeLabel("for_end")
+        val continueLabel = asmgen.makeLabel("for_continue")
+        asmgen.loopEndLabels.push(endLabel)
+        asmgen.loopContinueLabels.push(continueLabel)
+        when(iterableDt) {
+            DataType.ARRAY_B, DataType.ARRAY_UB -> {
+                val counterLabel = asmgen.makeLabel("for_counter")
+                if(stmt.loopRegister!=null) {
+
+                    // loop register over range
+
+                    if(stmt.loopRegister!= Register.A)
+                        throw AssemblyError("can only use A")
+                    when {
+                        range.step==1 -> {
+                            // step = 1
+                            asmgen.out("""
+                lda  #${range.first}
+                sta  $loopLabel+1
+                lda  #${range.last-range.first+1 and 255}
+                sta  $counterLabel
+$loopLabel      lda  #0                 ; modified""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                inc  $loopLabel+1
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                        range.step==-1 -> {
+                            // step = -1
+                            asmgen.out("""
+                lda  #${range.first}
+                sta  $loopLabel+1
+                lda  #${range.first-range.last+1 and 255}
+                sta  $counterLabel
+$loopLabel      lda  #0                 ; modified """)
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                dec  $loopLabel+1
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                        range.step >= 2 -> {
+                            // step >= 2
+                            asmgen.out("""
+                lda  #${(range.last-range.first) / range.step + 1}
+                sta  $counterLabel
+                lda  #${range.first}
+$loopLabel      pha""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  pla
+                dec  $counterLabel
+                beq  $endLabel
+                clc
+                adc  #${range.step}
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                        else -> {
+                            // step <= -2
+                            asmgen.out("""
+                lda  #${(range.first-range.last) / range.step.absoluteValue + 1}
+                sta  $counterLabel
+                lda  #${range.first}
+$loopLabel      pha""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  pla
+                dec  $counterLabel
+                beq  $endLabel
+                sec
+                sbc  #${range.step.absoluteValue}
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                    }
+
+                } else {
+
+                    // loop over byte range via loopvar
+                    val varname = asmgen.asmIdentifierName(stmt.loopVar!!)
+                    when {
+                        range.step==1 -> {
+                            // step = 1
+                            asmgen.out("""
+                lda  #${range.first}
+                sta  $varname
+                lda  #${range.last-range.first+1 and 255}
+                sta  $counterLabel
+$loopLabel""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                inc  $varname
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                        range.step==-1 -> {
+                            // step = -1
+                            asmgen.out("""
+                lda  #${range.first}
+                sta  $varname
+                lda  #${range.first-range.last+1 and 255}
+                sta  $counterLabel
+$loopLabel""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                dec  $varname
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                        range.step >= 2 -> {
+                            // step >= 2
+                            asmgen.out("""
+                lda  #${(range.last-range.first) / range.step + 1}
+                sta  $counterLabel
+                lda  #${range.first}
+                sta  $varname
+$loopLabel""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                lda  $varname
+                clc
+                adc  #${range.step}
+                sta  $varname
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                        else -> {
+                            // step <= -2
+                            asmgen.out("""
+                lda  #${(range.first-range.last) / range.step.absoluteValue + 1}
+                sta  $counterLabel
+                lda  #${range.first}
+                sta  $varname
+$loopLabel""")
+                            asmgen.translate(stmt.body)
+                            asmgen.out("""
+$continueLabel  dec  $counterLabel
+                beq  $endLabel
+                lda  $varname
+                sec
+                sbc  #${range.step.absoluteValue}
+                sta  $varname
+                jmp  $loopLabel
+$counterLabel   .byte  0                
+$endLabel""")
+                        }
+                    }
+                }
+            }
+            DataType.ARRAY_W, DataType.ARRAY_UW -> {
+                // loop over word range via loopvar
+                val varname = asmgen.asmIdentifierName(stmt.loopVar!!)
+                when {
+                    range.step == 1 -> {
+                        // word, step = 1
+                        val lastValue = range.last+1
+                        asmgen.out("""
+                lda  #<${range.first}
+                ldy  #>${range.first}
+                sta  $varname
+                sty  $varname+1
+$loopLabel""")
+                        asmgen.translate(stmt.body)
+                        asmgen.out("""
+$continueLabel  inc  $varname
+                bne  +
+                inc  $varname+1
++               lda  $varname
+                cmp  #<$lastValue
+                bne  +
+                lda  $varname+1
+                cmp  #>$lastValue
+                beq  $endLabel
++               jmp  $loopLabel
+$endLabel""")
+                    }
+                    range.step == -1 -> {
+                        // word, step = 1
+                        val lastValue = range.last-1
+                        asmgen.out("""
+                lda  #<${range.first}
+                ldy  #>${range.first}
+                sta  $varname
+                sty  $varname+1
+$loopLabel""")
+                        asmgen.translate(stmt.body)
+                        asmgen.out("""
+$continueLabel  lda  $varname
+                bne  +
+                dec  $varname+1
++               dec  $varname
+                lda  $varname
+                cmp  #<$lastValue
+                bne  +
+                lda  $varname+1
+                cmp  #>$lastValue
+                beq  $endLabel
++               jmp  $loopLabel
+$endLabel""")
+                    }
+                    range.step >= 2 -> {
+                        // word, step >= 2
+                        // note: range.last has already been adjusted by kotlin itself to actually be the last value of the sequence
+                        val lastValue = range.last+range.step
+                        asmgen.out("""
+                lda  #<${range.first}
+                ldy  #>${range.first}
+                sta  $varname
+                sty  $varname+1
+$loopLabel""")
+                        asmgen.translate(stmt.body)
+                        asmgen.out("""
+$continueLabel  clc
+                lda  $varname
+                adc  #<${range.step}
+                sta  $varname
+                lda  $varname+1
+                adc  #>${range.step}
+                sta  $varname+1
+                lda  $varname
+                cmp  #<$lastValue
+                bne  +
+                lda  $varname+1
+                cmp  #>$lastValue
+                beq  $endLabel
++               jmp  $loopLabel
+$endLabel""")
+                    }
+                    else -> {
+                        // step <= -2
+                        // note: range.last has already been adjusted by kotlin itself to actually be the last value of the sequence
+                        val lastValue = range.last+range.step
+                        asmgen.out("""
+                lda  #<${range.first}
+                ldy  #>${range.first}
+                sta  $varname
+                sty  $varname+1
+$loopLabel""")
+                        asmgen.translate(stmt.body)
+                        asmgen.out("""
+$continueLabel  sec
+                lda  $varname
+                sbc  #<${range.step.absoluteValue}
+                sta  $varname
+                lda  $varname+1
+                sbc  #>${range.step.absoluteValue}
+                sta  $varname+1
+                lda  $varname
+                cmp  #<$lastValue
+                bne  +
+                lda  $varname+1
+                cmp  #>$lastValue
+                beq  $endLabel
++               jmp  $loopLabel
+$endLabel""")
+                    }
+                }
+            }
+            else -> throw AssemblyError("range expression can only be byte or word")
+        }
+        asmgen.loopEndLabels.pop()
+        asmgen.loopContinueLabels.pop()
+    }
+
+}

compiler/src/prog8/compiler/target/c64/codegen/FunctionCallAsmGen.kt

@@ -0,0 +1,238 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.IFunctionCall
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.statements.AssignTarget
+import prog8.ast.statements.Subroutine
+import prog8.ast.statements.SubroutineParameter
+import prog8.compiler.toHex
+import prog8.compiler.AssemblyError
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_HI_HEX
+import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_HEX
+
+
+internal class FunctionCallAsmGen(private val program: Program, private val asmgen: AsmGen) {
+
+    internal fun translateFunctionCall(stmt: IFunctionCall) {
+        // output the code to setup the parameters and perform the actual call
+        // does NOT output the code to deal with the result values!
+        val sub = stmt.target.targetSubroutine(program.namespace) ?: throw AssemblyError("undefined subroutine ${stmt.target}")
+        if(Register.X in sub.asmClobbers)
+            asmgen.out("  stx  c64.SCRATCH_ZPREGX")        // we only save X for now (required! is the eval stack pointer), screw A and Y...
+
+        val subName = asmgen.asmIdentifierName(stmt.target)
+        if(stmt.args.isNotEmpty()) {
+            for(arg in sub.parameters.withIndex().zip(stmt.args)) {
+                translateFuncArguments(arg.first, arg.second, sub)
+            }
+        }
+        asmgen.out("  jsr  $subName")
+
+        if(Register.X in sub.asmClobbers)
+            asmgen.out("  ldx  c64.SCRATCH_ZPREGX")        // restore X again
+    }
+
+    private fun translateFuncArguments(parameter: IndexedValue<SubroutineParameter>, value: Expression, sub: Subroutine) {
+        val sourceIDt = value.inferType(program)
+        if(!sourceIDt.isKnown)
+            throw AssemblyError("arg type unknown")
+        val sourceDt = sourceIDt.typeOrElse(DataType.STRUCT)
+        if(!argumentTypeCompatible(sourceDt, parameter.value.type))
+            throw AssemblyError("argument type incompatible")
+        if(sub.asmParameterRegisters.isEmpty()) {
+            // pass parameter via a variable
+            val paramVar = parameter.value
+            val scopedParamVar = (sub.scopedname+"."+paramVar.name).split(".")
+            val target = AssignTarget(null, IdentifierReference(scopedParamVar, sub.position), null, null, sub.position)
+            target.linkParents(value.parent)
+            when (value) {
+                is NumericLiteralValue -> {
+                    // optimize when the argument is a constant literal
+                    when(parameter.value.type) {
+                        in ByteDatatypes -> asmgen.assignFromByteConstant(target, value.number.toShort())
+                        in WordDatatypes -> asmgen.assignFromWordConstant(target, value.number.toInt())
+                        DataType.FLOAT -> asmgen.assignFromFloatConstant(target, value.number.toDouble())
+                        in PassByReferenceDatatypes -> throw AssemblyError("can't pass string/array as arguments?")
+                        else -> throw AssemblyError("weird parameter datatype")
+                    }
+                }
+                is IdentifierReference -> {
+                    // optimize when the argument is a variable
+                    when (parameter.value.type) {
+                        in ByteDatatypes -> asmgen.assignFromByteVariable(target, value)
+                        in WordDatatypes -> asmgen.assignFromWordVariable(target, value)
+                        DataType.FLOAT -> asmgen.assignFromFloatVariable(target, value)
+                        in PassByReferenceDatatypes -> throw AssemblyError("can't pass string/array as arguments?")
+                        else -> throw AssemblyError("weird parameter datatype")
+                    }
+                }
+                is RegisterExpr -> {
+                    asmgen.assignFromRegister(target, value.register)
+                }
+                is DirectMemoryRead -> {
+                    when(value.addressExpression) {
+                        is NumericLiteralValue -> {
+                            val address = (value.addressExpression as NumericLiteralValue).number.toInt()
+                            asmgen.assignFromMemoryByte(target, address, null)
+                        }
+                        is IdentifierReference -> {
+                            asmgen.assignFromMemoryByte(target, null, value.addressExpression as IdentifierReference)
+                        }
+                        else -> {
+                            asmgen.translateExpression(value.addressExpression)
+                            asmgen.out("  jsr  prog8_lib.read_byte_from_address |  inx")
+                            asmgen.assignFromRegister(target, Register.A)
+                        }
+                    }
+                }
+                else -> {
+                    asmgen.translateExpression(value)
+                    asmgen.assignFromEvalResult(target)
+                }
+            }
+        } else {
+            // pass parameter via a register parameter
+            val paramRegister = sub.asmParameterRegisters[parameter.index]
+            val statusflag = paramRegister.statusflag
+            val register = paramRegister.registerOrPair
+            val stack = paramRegister.stack
+            when {
+                stack -> {
+                    // push arg onto the stack
+                    // note: argument order is reversed (first argument will be deepest on the stack)
+                    asmgen.translateExpression(value)
+                }
+                statusflag!=null -> {
+                    if (statusflag == Statusflag.Pc) {
+                        // this param needs to be set last, right before the jsr
+                        // for now, this is already enforced on the subroutine definition by the Ast Checker
+                        when(value) {
+                            is NumericLiteralValue -> {
+                                val carrySet = value.number.toInt() != 0
+                                asmgen.out(if(carrySet) "  sec" else "  clc")
+                            }
+                            is IdentifierReference -> {
+                                val sourceName = asmgen.asmIdentifierName(value)
+                                asmgen.out("""
+            lda  $sourceName
+            beq  +
+            sec  
+            bcs  ++
++           clc
++
+""")
+                            }
+                            is RegisterExpr -> {
+                                when(value.register) {
+                                    Register.A -> asmgen.out("  cmp  #0")
+                                    Register.X -> asmgen.out("  txa")
+                                    Register.Y -> asmgen.out("  tya")
+                                }
+                                asmgen.out("""
+            beq  +
+            sec
+            bcs  ++
++           clc
++
+""")
+                            }
+                            else -> {
+                                asmgen.translateExpression(value)
+                                asmgen.out("""
+            inx                        
+            lda  $ESTACK_LO_HEX,x
+            beq  +
+            sec  
+            bcs  ++
++           clc
++
+""")
+                            }
+                        }
+                    }
+                    else throw AssemblyError("can only use Carry as status flag parameter")
+                }
+                register!=null && register.name.length==1 -> {
+                    when (value) {
+                        is NumericLiteralValue -> {
+                            val target = AssignTarget(Register.valueOf(register.name), null, null, null, sub.position)
+                            target.linkParents(value.parent)
+                            asmgen.assignFromByteConstant(target, value.number.toShort())
+                        }
+                        is IdentifierReference -> {
+                            val target = AssignTarget(Register.valueOf(register.name), null, null, null, sub.position)
+                            target.linkParents(value.parent)
+                            asmgen.assignFromByteVariable(target, value)
+                        }
+                        else -> {
+                            asmgen.translateExpression(value)
+                            when(register) {
+                                RegisterOrPair.A -> asmgen.out("  inx | lda  $ESTACK_LO_HEX,x")
+                                RegisterOrPair.X -> throw AssemblyError("can't pop into X register - use a variable instead")
+                                RegisterOrPair.Y -> asmgen.out("  inx | ldy  $ESTACK_LO_HEX,x")
+                                else -> throw AssemblyError("cannot assign to register pair")
+                            }
+                        }
+                    }
+                }
+                register!=null && register.name.length==2 -> {
+                    // register pair as a 16-bit value (only possible for subroutine parameters)
+                    when (value) {
+                        is NumericLiteralValue -> {
+                            // optimize when the argument is a constant literal
+                            val hex = value.number.toHex()
+                            when (register) {
+                                RegisterOrPair.AX -> asmgen.out("  lda  #<$hex  |  ldx  #>$hex")
+                                RegisterOrPair.AY -> asmgen.out("  lda  #<$hex  |  ldy  #>$hex")
+                                RegisterOrPair.XY -> asmgen.out("  ldx  #<$hex  |  ldy  #>$hex")
+                                else -> {}
+                            }
+                        }
+                        is AddressOf -> {
+                            // optimize when the argument is an address of something
+                            val sourceName = asmgen.asmIdentifierName(value.identifier)
+                            when (register) {
+                                RegisterOrPair.AX -> asmgen.out("  lda  #<$sourceName  |  ldx  #>$sourceName")
+                                RegisterOrPair.AY -> asmgen.out("  lda  #<$sourceName  |  ldy  #>$sourceName")
+                                RegisterOrPair.XY -> asmgen.out("  ldx  #<$sourceName  |  ldy  #>$sourceName")
+                                else -> {}
+                            }
+                        }
+                        is IdentifierReference -> {
+                            val sourceName = asmgen.asmIdentifierName(value)
+                            when (register) {
+                                RegisterOrPair.AX -> asmgen.out("  lda  $sourceName  |  ldx  $sourceName+1")
+                                RegisterOrPair.AY -> asmgen.out("  lda  $sourceName  |  ldy  $sourceName+1")
+                                RegisterOrPair.XY -> asmgen.out("  ldx  $sourceName  |  ldy  $sourceName+1")
+                                else -> {}
+                            }
+                        }
+                        else -> {
+                            asmgen.translateExpression(value)
+                            if (register == RegisterOrPair.AX || register == RegisterOrPair.XY)
+                                throw AssemblyError("can't use X register here - use a variable")
+                            else if (register == RegisterOrPair.AY)
+                                asmgen.out("  inx |  lda  $ESTACK_LO_HEX,x  |  ldy  $ESTACK_HI_HEX,x")
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    private fun argumentTypeCompatible(argType: DataType, paramType: DataType): Boolean {
+        if(argType isAssignableTo paramType)
+            return true
+
+        // we have a special rule for some types.
+        // strings are assignable to UWORD, for example, and vice versa
+        if(argType==DataType.STR && paramType==DataType.UWORD)
+            return true
+        if(argType==DataType.UWORD && paramType == DataType.STR)
+            return true
+
+        return false
+    }
+}

compiler/src/prog8/compiler/target/c64/codegen/PostIncrDecrAsmGen.kt

@@ -0,0 +1,150 @@
+package prog8.compiler.target.c64.codegen
+
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.IdentifierReference
+import prog8.ast.expressions.NumericLiteralValue
+import prog8.ast.expressions.RegisterExpr
+import prog8.ast.statements.PostIncrDecr
+import prog8.compiler.toHex
+import prog8.compiler.AssemblyError
+import prog8.compiler.target.c64.C64MachineDefinition.C64Zeropage
+
+
+internal class PostIncrDecrAsmGen(private val program: Program, private val asmgen: AsmGen) {
+    internal fun translate(stmt: PostIncrDecr) {
+        val incr = stmt.operator=="++"
+        val targetIdent = stmt.target.identifier
+        val targetMemory = stmt.target.memoryAddress
+        val targetArrayIdx = stmt.target.arrayindexed
+        val targetRegister = stmt.target.register
+        when {
+            targetRegister!=null -> {
+                when(targetRegister) {
+                    Register.A -> {
+                        if(incr)
+                            asmgen.out("  clc |  adc  #1 ")
+                        else
+                            asmgen.out("  sec |  sbc  #1 ")
+                    }
+                    Register.X -> {
+                        if(incr) asmgen.out("  inx") else asmgen.out("  dex")
+                    }
+                    Register.Y -> {
+                        if(incr) asmgen.out("  iny") else asmgen.out("  dey")
+                    }
+                }
+            }
+            targetIdent!=null -> {
+                val what = asmgen.asmIdentifierName(targetIdent)
+                val dt = stmt.target.inferType(program, stmt).typeOrElse(DataType.STRUCT)
+                when (dt) {
+                    in ByteDatatypes -> asmgen.out(if (incr) "  inc  $what" else "  dec  $what")
+                    in WordDatatypes -> {
+                        if(incr)
+                            asmgen.out(" inc  $what |  bne  + |  inc  $what+1 |+")
+                        else
+                            asmgen.out("""
+        lda  $what
+        bne  +
+        dec  $what+1
++       dec  $what 
+""")
+                    }
+                    DataType.FLOAT -> {
+                        asmgen.out("  lda  #<$what |  ldy  #>$what")
+                        asmgen.out(if(incr) "  jsr  c64flt.inc_var_f" else "  jsr  c64flt.dec_var_f")
+                    }
+                    else -> throw AssemblyError("need numeric type")
+                }
+            }
+            targetMemory!=null -> {
+                when (val addressExpr = targetMemory.addressExpression) {
+                    is NumericLiteralValue -> {
+                        val what = addressExpr.number.toHex()
+                        asmgen.out(if(incr) "  inc  $what" else "  dec  $what")
+                    }
+                    is IdentifierReference -> {
+                        val what = asmgen.asmIdentifierName(addressExpr)
+                        asmgen.out(if(incr) "  inc  $what" else "  dec  $what")
+                    }
+                    else -> throw AssemblyError("weird target type $targetMemory")
+                }
+            }
+            targetArrayIdx!=null -> {
+                val index = targetArrayIdx.arrayspec.index
+                val what = asmgen.asmIdentifierName(targetArrayIdx.identifier)
+                val arrayDt = targetArrayIdx.identifier.inferType(program).typeOrElse(DataType.STRUCT)
+                val elementDt = ArrayElementTypes.getValue(arrayDt)
+                when(index) {
+                    is NumericLiteralValue -> {
+                        val indexValue = index.number.toInt() * elementDt.memorySize()
+                        when(elementDt) {
+                            in ByteDatatypes -> asmgen.out(if (incr) "  inc  $what+$indexValue" else "  dec  $what+$indexValue")
+                            in WordDatatypes -> {
+                                if(incr)
+                                    asmgen.out(" inc  $what+$indexValue |  bne  + |  inc  $what+$indexValue+1 |+")
+                                else
+                                    asmgen.out("""
+        lda  $what+$indexValue
+        bne  +
+        dec  $what+$indexValue+1
++       dec  $what+$indexValue 
+""")
+                            }
+                            DataType.FLOAT -> {
+                                asmgen.out("  lda  #<$what+$indexValue |  ldy  #>$what+$indexValue")
+                                asmgen.out(if(incr) "  jsr  c64flt.inc_var_f" else "  jsr  c64flt.dec_var_f")
+                            }
+                            else -> throw AssemblyError("need numeric type")
+                        }
+                    }
+                    is RegisterExpr -> {
+                        // TODO optimize common cases
+                        asmgen.translateArrayIndexIntoA(targetArrayIdx)
+                        incrDecrArrayvalueWithIndexA(incr, arrayDt, what)
+                    }
+                    is IdentifierReference -> {
+                        // TODO optimize common cases
+                        asmgen.translateArrayIndexIntoA(targetArrayIdx)
+                        incrDecrArrayvalueWithIndexA(incr, arrayDt, what)
+                    }
+                    else -> {
+                        // TODO optimize common cases
+                        asmgen.translateArrayIndexIntoA(targetArrayIdx)
+                        incrDecrArrayvalueWithIndexA(incr, arrayDt, what)
+                    }
+                }
+            }
+            else -> throw AssemblyError("weird target type ${stmt.target}")
+        }
+    }
+
+    private fun incrDecrArrayvalueWithIndexA(incr: Boolean, arrayDt: DataType, arrayVarName: String) {
+        asmgen.out("  stx  ${C64Zeropage.SCRATCH_REG_X} |  tax")
+        when(arrayDt) {
+            DataType.STR,
+            DataType.ARRAY_UB, DataType.ARRAY_B -> {
+                asmgen.out(if(incr) "  inc  $arrayVarName,x" else "  dec  $arrayVarName,x")
+            }
+            DataType.ARRAY_UW, DataType.ARRAY_W -> {
+                if(incr)
+                    asmgen.out(" inc  $arrayVarName,x |  bne  + |  inc  $arrayVarName+1,x |+")
+                else
+                    asmgen.out("""
+        lda  $arrayVarName,x
+        bne  +
+        dec  $arrayVarName+1,x
++       dec  $arrayVarName 
+""")
+            }
+            DataType.ARRAY_F -> {
+                asmgen.out("  lda  #<$arrayVarName |  ldy  #>$arrayVarName")
+                asmgen.out(if(incr) "  jsr  c64flt.inc_indexed_var_f" else "  jsr  c64flt.dec_indexed_var_f")
+            }
+            else -> throw AssemblyError("weird array dt")
+        }
+        asmgen.out("  ldx  ${C64Zeropage.SCRATCH_REG_X}")
+    }
+
+}

compiler/src/prog8/functions/BuiltinFunctions.kt

@@ -1,16 +1,22 @@
 package prog8.functions
 
-import prog8.ast.*
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
 import prog8.compiler.CompilerException
 import kotlin.math.*
 
 
 class BuiltinFunctionParam(val name: String, val possibleDatatypes: Set<DataType>)
 
+
+typealias ConstExpressionCaller = (args: List<Expression>, position: Position, program: Program) -> NumericLiteralValue
+
+
 class FunctionSignature(val pure: Boolean,      // does it have side effects?
                         val parameters: List<BuiltinFunctionParam>,
                         val returntype: DataType?,
-                        val constExpressionFunc: ((args: List<IExpression>, position: Position, program: Program) -> LiteralValue)? = null)
+                        val constExpressionFunc: ConstExpressionCaller? = null)
 
 
 val BuiltinFunctions = mapOf(
@@ -21,13 +27,16 @@ val BuiltinFunctions = mapOf(
     "ror2"        to FunctionSignature(false, listOf(BuiltinFunctionParam("item", setOf(DataType.UBYTE, DataType.UWORD))), null),
     "lsl"         to FunctionSignature(false, listOf(BuiltinFunctionParam("item", IntegerDatatypes)), null),
     "lsr"         to FunctionSignature(false, listOf(BuiltinFunctionParam("item", IntegerDatatypes)), null),
+    "sort"        to FunctionSignature(false, listOf(BuiltinFunctionParam("array", ArrayDatatypes)), null),
+    "reverse"     to FunctionSignature(false, listOf(BuiltinFunctionParam("array", ArrayDatatypes)), null),
         // these few have a return value depending on the argument(s):
-    "max"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArgOutputNumber(a, p, prg) { it.max()!! }},    // type depends on args
-    "min"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArgOutputNumber(a, p, prg) { it.min()!! }},    // type depends on args
-    "sum"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArgOutputNumber(a, p, prg) { it.sum() }},      // type depends on args
+    "max"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArg(a, p, prg, ::builtinMax) },    // type depends on args
+    "min"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArg(a, p, prg, ::builtinMin) },    // type depends on args
+    "sum"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArg(a, p, prg, ::builtinSum) },      // type depends on args
     "abs"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", NumericDatatypes)), null, ::builtinAbs),      // type depends on argument
     "len"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", IterableDatatypes)), null, ::builtinLen),    // type is UBYTE or UWORD depending on actual length
         // normal functions follow:
+    "sgn"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", NumericDatatypes)), DataType.BYTE, ::builtinSgn ),
     "sin"         to FunctionSignature(true, listOf(BuiltinFunctionParam("rads", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::sin) },
     "sin8"        to FunctionSignature(true, listOf(BuiltinFunctionParam("angle8", setOf(DataType.UBYTE))), DataType.BYTE, ::builtinSin8 ),
     "sin8u"       to FunctionSignature(true, listOf(BuiltinFunctionParam("angle8", setOf(DataType.UBYTE))), DataType.UBYTE, ::builtinSin8u ),
@@ -46,12 +55,11 @@ val BuiltinFunctions = mapOf(
     "sqrt"        to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::sqrt) },
     "rad"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::toRadians) },
     "deg"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::toDegrees) },
-    "avg"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), DataType.FLOAT, ::builtinAvg),
     "round"       to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArgOutputWord(a, p, prg, Math::round) },
     "floor"       to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArgOutputWord(a, p, prg, Math::floor) },
     "ceil"        to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArgOutputWord(a, p, prg, Math::ceil) },
-    "any"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), DataType.UBYTE) { a, p, prg -> collectionArgOutputBoolean(a, p, prg) { it.any { v -> v != 0.0} }},
-    "all"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), DataType.UBYTE) { a, p, prg -> collectionArgOutputBoolean(a, p, prg) { it.all { v -> v != 0.0} }},
+    "any"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), DataType.UBYTE) { a, p, prg -> collectionArg(a, p, prg, ::builtinAny) },
+    "all"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), DataType.UBYTE) { a, p, prg -> collectionArg(a, p, prg, ::builtinAll) },
     "lsb"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.UWORD, DataType.WORD))), DataType.UBYTE) { a, p, prg -> oneIntArgOutputInt(a, p, prg) { x: Int -> x and 255 }},
     "msb"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.UWORD, DataType.WORD))), DataType.UBYTE) { a, p, prg -> oneIntArgOutputInt(a, p, prg) { x: Int -> x ushr 8 and 255}},
     "mkword"      to FunctionSignature(true, listOf(
@@ -69,64 +77,52 @@ val BuiltinFunctions = mapOf(
     "read_flags"  to FunctionSignature(false, emptyList(), DataType.UBYTE),
     "swap"        to FunctionSignature(false, listOf(BuiltinFunctionParam("first", NumericDatatypes), BuiltinFunctionParam("second", NumericDatatypes)), null),
     "memcopy"     to FunctionSignature(false, listOf(
-                                                        BuiltinFunctionParam("from", IterableDatatypes + setOf(DataType.UWORD)),
-                                                        BuiltinFunctionParam("to", IterableDatatypes + setOf(DataType.UWORD)),
+                                                        BuiltinFunctionParam("from", IterableDatatypes + DataType.UWORD),
+                                                        BuiltinFunctionParam("to", IterableDatatypes + DataType.UWORD),
                                                         BuiltinFunctionParam("numbytes", setOf(DataType.UBYTE))), null),
     "memset"      to FunctionSignature(false, listOf(
-                                                        BuiltinFunctionParam("address", IterableDatatypes + setOf(DataType.UWORD)),
+                                                        BuiltinFunctionParam("address", IterableDatatypes + DataType.UWORD),
                                                         BuiltinFunctionParam("numbytes", setOf(DataType.UWORD)),
                                                         BuiltinFunctionParam("bytevalue", ByteDatatypes)), null),
     "memsetw"     to FunctionSignature(false, listOf(
-                                                        BuiltinFunctionParam("address", IterableDatatypes + setOf(DataType.UWORD)),
+                                                        BuiltinFunctionParam("address", IterableDatatypes + DataType.UWORD),
                                                         BuiltinFunctionParam("numwords", setOf(DataType.UWORD)),
                                                         BuiltinFunctionParam("wordvalue", setOf(DataType.UWORD, DataType.WORD))), null),
-    "strlen"      to FunctionSignature(true, listOf(BuiltinFunctionParam("string", StringDatatypes)), DataType.UBYTE, ::builtinStrlen),
-    "vm_write_memchr"  to FunctionSignature(false, listOf(BuiltinFunctionParam("address", setOf(DataType.UWORD))), null),
-    "vm_write_memstr"  to FunctionSignature(false, listOf(BuiltinFunctionParam("address", setOf(DataType.UWORD))), null),
-    "vm_write_num"     to FunctionSignature(false, listOf(BuiltinFunctionParam("number", NumericDatatypes)), null),
-    "vm_write_char"    to FunctionSignature(false, listOf(BuiltinFunctionParam("char", setOf(DataType.UBYTE))), null),
-    "vm_write_str"     to FunctionSignature(false, listOf(BuiltinFunctionParam("string", StringDatatypes)), null),
-    "vm_input_str"     to FunctionSignature(false, listOf(BuiltinFunctionParam("intovar", StringDatatypes)), null),
-    "vm_gfx_clearscr"  to FunctionSignature(false, listOf(BuiltinFunctionParam("color", setOf(DataType.UBYTE))), null),
-    "vm_gfx_pixel"     to FunctionSignature(false, listOf(
-                                                        BuiltinFunctionParam("x", IntegerDatatypes),
-                                                        BuiltinFunctionParam("y", IntegerDatatypes),
-                                                        BuiltinFunctionParam("color", IntegerDatatypes)), null),
-    "vm_gfx_line"     to FunctionSignature(false, listOf(
-                                                        BuiltinFunctionParam("x1", IntegerDatatypes),
-                                                        BuiltinFunctionParam("y1", IntegerDatatypes),
-                                                        BuiltinFunctionParam("x2", IntegerDatatypes),
-                                                        BuiltinFunctionParam("y2", IntegerDatatypes),
-                                                        BuiltinFunctionParam("color", IntegerDatatypes)), null),
-    "vm_gfx_text"      to FunctionSignature(false, listOf(
-                                                        BuiltinFunctionParam("x", IntegerDatatypes),
-                                                        BuiltinFunctionParam("y", IntegerDatatypes),
-                                                        BuiltinFunctionParam("color", IntegerDatatypes),
-                                                        BuiltinFunctionParam("text", StringDatatypes)),
-                                                        null)
+    "strlen"      to FunctionSignature(true, listOf(BuiltinFunctionParam("string", setOf(DataType.STR))), DataType.UBYTE, ::builtinStrlen)
 )
 
+fun builtinMax(array: List<Number>): Number = array.maxBy { it.toDouble() }!!
 
-fun builtinFunctionReturnType(function: String, args: List<IExpression>, program: Program): DataType? {
+fun builtinMin(array: List<Number>): Number = array.minBy { it.toDouble() }!!
 
-    fun datatypeFromIterableArg(arglist: IExpression): DataType {
-        if(arglist is LiteralValue) {
-            if(arglist.type==DataType.ARRAY_UB || arglist.type==DataType.ARRAY_UW || arglist.type==DataType.ARRAY_F) {
-                val dt = arglist.arrayvalue!!.map {it.inferType(program)}
-                if(dt.any { it!=DataType.UBYTE && it!=DataType.UWORD && it!=DataType.FLOAT}) {
-                    throw FatalAstException("fuction $function only accepts arraysize of numeric values")
-                }
-                if(dt.any { it==DataType.FLOAT }) return DataType.FLOAT
-                if(dt.any { it==DataType.UWORD }) return DataType.UWORD
-                return DataType.UBYTE
+fun builtinSum(array: List<Number>): Number = array.sumByDouble { it.toDouble() }
+
+fun builtinAny(array: List<Number>): Number = if(array.any { it.toDouble()!=0.0 }) 1 else 0
+
+fun builtinAll(array: List<Number>): Number = if(array.all { it.toDouble()!=0.0 }) 1 else 0
+
+
+fun builtinFunctionReturnType(function: String, args: List<Expression>, program: Program): InferredTypes.InferredType {
+
+    fun datatypeFromIterableArg(arglist: Expression): DataType {
+        if(arglist is ArrayLiteralValue) {
+            val dt = arglist.value.map {it.inferType(program).typeOrElse(DataType.STRUCT)}.toSet()
+            if(dt.any { it !in NumericDatatypes }) {
+                throw FatalAstException("fuction $function only accepts array of numeric values")
             }
+            if(DataType.FLOAT in dt) return DataType.FLOAT
+            if(DataType.UWORD in dt) return DataType.UWORD
+            if(DataType.WORD in dt) return DataType.WORD
+            if(DataType.BYTE in dt) return DataType.BYTE
+            return DataType.UBYTE
         }
         if(arglist is IdentifierReference) {
-            val dt = arglist.inferType(program)
-            return when(dt) {
-                in NumericDatatypes -> dt!!
-                in StringDatatypes -> dt!!
-                in ArrayDatatypes -> ArrayElementTypes.getValue(dt!!)
+            val idt = arglist.inferType(program)
+            if(!idt.isKnown)
+                throw FatalAstException("couldn't determine type of iterable $arglist")
+            return when(val dt = idt.typeOrElse(DataType.STRUCT)) {
+                DataType.STR, in NumericDatatypes -> dt
+                in ArrayDatatypes -> ArrayElementTypes.getValue(dt)
                 else -> throw FatalAstException("function '$function' requires one argument which is an iterable")
             }
         }
@@ -135,46 +131,43 @@ fun builtinFunctionReturnType(function: String, args: List<IExpression>, program
 
     val func = BuiltinFunctions.getValue(function)
     if(func.returntype!=null)
-        return func.returntype
+        return InferredTypes.knownFor(func.returntype)
     // function has return values, but the return type depends on the arguments
 
     return when (function) {
         "abs" -> {
             val dt = args.single().inferType(program)
-            when(dt) {
-                in ByteDatatypes -> DataType.UBYTE
-                in WordDatatypes -> DataType.UWORD
-                DataType.FLOAT -> DataType.FLOAT
-                else -> throw FatalAstException("weird datatype passed to abs $dt")
-            }
+            if(dt.typeOrElse(DataType.STRUCT) in NumericDatatypes)
+                return dt
+            else
+                throw FatalAstException("weird datatype passed to abs $dt")
         }
         "max", "min" -> {
-            val dt = datatypeFromIterableArg(args.single())
-            when(dt) {
-                in NumericDatatypes -> dt
-                in StringDatatypes -> DataType.UBYTE
-                in ArrayDatatypes -> ArrayElementTypes.getValue(dt)
-                else -> null
+            when(val dt = datatypeFromIterableArg(args.single())) {
+                DataType.STR -> InferredTypes.knownFor(DataType.UBYTE)
+                in NumericDatatypes -> InferredTypes.knownFor(dt)
+                in ArrayDatatypes -> InferredTypes.knownFor(ArrayElementTypes.getValue(dt))
+                else -> InferredTypes.unknown()
             }
         }
         "sum" -> {
             when(datatypeFromIterableArg(args.single())) {
-                DataType.UBYTE, DataType.UWORD -> DataType.UWORD
-                DataType.BYTE, DataType.WORD -> DataType.WORD
-                DataType.FLOAT -> DataType.FLOAT
-                DataType.ARRAY_UB, DataType.ARRAY_UW -> DataType.UWORD
-                DataType.ARRAY_B, DataType.ARRAY_W -> DataType.WORD
-                DataType.ARRAY_F -> DataType.FLOAT
-                in StringDatatypes -> DataType.UWORD
-                else -> null
+                DataType.UBYTE, DataType.UWORD -> InferredTypes.knownFor(DataType.UWORD)
+                DataType.BYTE, DataType.WORD -> InferredTypes.knownFor(DataType.WORD)
+                DataType.FLOAT -> InferredTypes.knownFor(DataType.FLOAT)
+                DataType.ARRAY_UB, DataType.ARRAY_UW -> InferredTypes.knownFor(DataType.UWORD)
+                DataType.ARRAY_B, DataType.ARRAY_W -> InferredTypes.knownFor(DataType.WORD)
+                DataType.ARRAY_F -> InferredTypes.knownFor(DataType.FLOAT)
+                DataType.STR -> InferredTypes.knownFor(DataType.UWORD)
+                else -> InferredTypes.unknown()
             }
         }
         "len" -> {
             // a length can be >255 so in that case, the result is an UWORD instead of an UBYTE
             // but to avoid a lot of code duplication we simply assume UWORD in all cases for now
-            return DataType.UWORD
+            return InferredTypes.knownFor(DataType.UWORD)
         }
-        else -> return null
+        else -> return InferredTypes.unknown()
     }
 }
 
@@ -182,181 +175,104 @@ fun builtinFunctionReturnType(function: String, args: List<IExpression>, program
 class NotConstArgumentException: AstException("not a const argument to a built-in function")
 
 
-private fun oneDoubleArg(args: List<IExpression>, position: Position, program: Program, function: (arg: Double)->Number): LiteralValue {
+private fun oneDoubleArg(args: List<Expression>, position: Position, program: Program, function: (arg: Double)->Number): NumericLiteralValue {
     if(args.size!=1)
         throw SyntaxError("built-in function requires one floating point argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    if(constval.type!=DataType.FLOAT)
-        throw SyntaxError("built-in function requires one floating point argument", position)
-
-    val float = constval.asNumericValue?.toDouble()!!
+    val float = constval.number.toDouble()
     return numericLiteral(function(float), args[0].position)
 }
 
-private fun oneDoubleArgOutputWord(args: List<IExpression>, position: Position, program: Program, function: (arg: Double)->Number): LiteralValue {
+private fun oneDoubleArgOutputWord(args: List<Expression>, position: Position, program: Program, function: (arg: Double)->Number): NumericLiteralValue {
     if(args.size!=1)
         throw SyntaxError("built-in function requires one floating point argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    if(constval.type!=DataType.FLOAT)
-        throw SyntaxError("built-in function requires one floating point argument", position)
-    return LiteralValue(DataType.WORD, wordvalue=function(constval.asNumericValue!!.toDouble()).toInt(), position=args[0].position)
+    val float = constval.number.toDouble()
+    return NumericLiteralValue(DataType.WORD, function(float).toInt(), args[0].position)
 }
 
-private fun oneIntArgOutputInt(args: List<IExpression>, position: Position, program: Program, function: (arg: Int)->Number): LiteralValue {
+private fun oneIntArgOutputInt(args: List<Expression>, position: Position, program: Program, function: (arg: Int)->Number): NumericLiteralValue {
     if(args.size!=1)
         throw SyntaxError("built-in function requires one integer argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    if(constval.type!=DataType.UBYTE && constval.type!=DataType.UWORD)
+    if(constval.type != DataType.UBYTE && constval.type!= DataType.UWORD)
         throw SyntaxError("built-in function requires one integer argument", position)
 
-    val integer = constval.asNumericValue?.toInt()!!
+    val integer = constval.number.toInt()
     return numericLiteral(function(integer).toInt(), args[0].position)
 }
 
-private fun collectionArgOutputNumber(args: List<IExpression>, position: Position,
-                                      program: Program,
-                                      function: (arg: Collection<Double>)->Number): LiteralValue {
+private fun collectionArg(args: List<Expression>, position: Position, program: Program, function: (arg: List<Number>)->Number): NumericLiteralValue {
     if(args.size!=1)
         throw SyntaxError("builtin function requires one non-scalar argument", position)
-    val iterable = args[0].constValue(program) ?: throw NotConstArgumentException()
 
-    val result = if(iterable.arrayvalue != null) {
-        val constants = iterable.arrayvalue.map { it.constValue(program)?.asNumericValue }
-        if(null in constants)
-            throw NotConstArgumentException()
-        function(constants.map { it!!.toDouble() }).toDouble()
-    } else {
-        when(iterable.type) {
-            DataType.UBYTE, DataType.UWORD, DataType.FLOAT -> throw SyntaxError("function expects an iterable type", position)
-            else -> {
-                val heapId = iterable.heapId ?: throw FatalAstException("iterable value should be on the heap")
-                val array = program.heap.get(heapId).array ?: throw SyntaxError("function expects an iterable type", position)
-                function(array.map {
-                    if(it.integer!=null)
-                        it.integer.toDouble()
-                    else
-                        throw FatalAstException("cannot perform function over array that contains other values besides constant integers")
-                })
-            }
-        }
-    }
-    return numericLiteral(result, args[0].position)
+    val array= args[0] as? ArrayLiteralValue ?: throw NotConstArgumentException()
+    val constElements = array.value.map{it.constValue(program)?.number}
+    if(constElements.contains(null))
+        throw NotConstArgumentException()
+
+    return NumericLiteralValue.optimalNumeric(function(constElements.mapNotNull { it }), args[0].position)
 }
 
-private fun collectionArgOutputBoolean(args: List<IExpression>, position: Position,
-                                       program: Program,
-                                       function: (arg: Collection<Double>)->Boolean): LiteralValue {
-    if(args.size!=1)
-        throw SyntaxError("builtin function requires one non-scalar argument", position)
-    val iterable = args[0].constValue(program) ?: throw NotConstArgumentException()
-
-    val result = if(iterable.arrayvalue != null) {
-        val constants = iterable.arrayvalue.map { it.constValue(program)?.asNumericValue }
-        if(null in constants)
-            throw NotConstArgumentException()
-        function(constants.map { it!!.toDouble() })
-    } else {
-        val array = program.heap.get(iterable.heapId!!).array ?: throw SyntaxError("function requires array argument", position)
-        function(array.map {
-            if(it.integer!=null)
-                it.integer.toDouble()
-            else
-                throw FatalAstException("cannot perform function over array that contains other values besides constant integers")
-        })
-    }
-    return LiteralValue.fromBoolean(result, position)
-}
-
-private fun builtinAbs(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinAbs(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     // 1 arg, type = float or int, result type= isSameAs as argument type
     if(args.size!=1)
         throw SyntaxError("abs requires one numeric argument", position)
 
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val number = constval.asNumericValue
-    return when (number) {
-        is Int, is Byte, is Short -> numericLiteral(abs(number.toInt()), args[0].position)
-        is Double -> numericLiteral(abs(number.toDouble()), args[0].position)
+    return when (constval.type) {
+        in IntegerDatatypes -> numericLiteral(abs(constval.number.toInt()), args[0].position)
+        DataType.FLOAT -> numericLiteral(abs(constval.number.toDouble()), args[0].position)
         else -> throw SyntaxError("abs requires one numeric argument", position)
     }
 }
 
-private fun builtinAvg(args: List<IExpression>, position: Position, program: Program): LiteralValue {
-    if(args.size!=1)
-        throw SyntaxError("avg requires array argument", position)
-    val iterable = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val result = if(iterable.arrayvalue!=null) {
-        val constants = iterable.arrayvalue.map { it.constValue(program)?.asNumericValue }
-        if (null in constants)
-            throw NotConstArgumentException()
-        (constants.map { it!!.toDouble() }).average()
-    }
-    else {
-        val heapId = iterable.heapId!!
-        val integerarray = program.heap.get(heapId).array
-        if(integerarray!=null) {
-            if (integerarray.all { it.integer != null }) {
-                integerarray.map { it.integer!! }.average()
-            } else {
-                throw ExpressionError("cannot avg() over array that does not only contain constant numerical values", position)
-            }
-        } else {
-            val doublearray = program.heap.get(heapId).doubleArray
-            doublearray?.average() ?: throw SyntaxError("avg requires array argument", position)
-        }
-    }
-    return numericLiteral(result, args[0].position)
-}
-
-private fun builtinStrlen(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinStrlen(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("strlen requires one argument", position)
     val argument = args[0].constValue(program) ?: throw NotConstArgumentException()
-    if(argument.type !in StringDatatypes)
+    if(argument.type != DataType.STR)
         throw SyntaxError("strlen must have string argument", position)
-    val string = argument.strvalue!!
-    val zeroIdx = string.indexOf('\u0000')
-    return if(zeroIdx>=0)
-        LiteralValue.optimalInteger(zeroIdx, position=position)
-    else
-        LiteralValue.optimalInteger(string.length, position=position)
+
+    throw NotConstArgumentException()       // this function is not considering the string argument a constant
 }
 
-private fun builtinLen(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinLen(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     // note: in some cases the length is > 255 and then we have to return a UWORD type instead of a UBYTE.
     if(args.size!=1)
         throw SyntaxError("len requires one argument", position)
-    var argument = args[0].constValue(program)
-    if(argument==null) {
-        val directMemVar = ((args[0] as? DirectMemoryRead)?.addressExpression as? IdentifierReference)?.targetVarDecl(program.namespace)
-        val arraySize = directMemVar?.arraysize?.size()
-        if(arraySize != null)
-            return LiteralValue.optimalInteger(arraySize, position)
-        if(args[0] !is IdentifierReference)
-            throw SyntaxError("len argument should be an identifier, but is ${args[0]}", position)
-        val target = (args[0] as IdentifierReference).targetStatement(program.namespace)
-        val argValue = (target as? VarDecl)?.value
-        argument = argValue?.constValue(program)
-                ?: throw NotConstArgumentException()
-    }
-    return when(argument.type) {
+    val constArg = args[0].constValue(program)
+    if(constArg!=null)
+        throw SyntaxError("len of weird argument ${args[0]}", position)
+
+    val directMemVar = ((args[0] as? DirectMemoryRead)?.addressExpression as? IdentifierReference)?.targetVarDecl(program.namespace)
+    var arraySize = directMemVar?.arraysize?.size()
+    if(arraySize != null)
+        return NumericLiteralValue.optimalInteger(arraySize, position)
+    if(args[0] is ArrayLiteralValue)
+        return NumericLiteralValue.optimalInteger((args[0] as ArrayLiteralValue).value.size, position)
+    if(args[0] !is IdentifierReference)
+        throw SyntaxError("len argument should be an identifier, but is ${args[0]}", position)
+    val target = (args[0] as IdentifierReference).targetVarDecl(program.namespace)!!
+
+    return when(target.datatype) {
         DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W -> {
-            val arraySize = argument.arrayvalue?.size ?: program.heap.get(argument.heapId!!).arraysize
+            arraySize = target.arraysize!!.size()!!
             if(arraySize>256)
-                throw CompilerException("array length exceeds byte limit ${argument.position}")
-            LiteralValue.optimalInteger(arraySize, args[0].position)
+                throw CompilerException("array length exceeds byte limit ${target.position}")
+            NumericLiteralValue.optimalInteger(arraySize, args[0].position)
         }
         DataType.ARRAY_F -> {
-            val arraySize = argument.arrayvalue?.size ?: program.heap.get(argument.heapId!!).arraysize
+            arraySize = target.arraysize!!.size()!!
             if(arraySize>256)
-                throw CompilerException("array length exceeds byte limit ${argument.position}")
-            LiteralValue.optimalInteger(arraySize, args[0].position)
+                throw CompilerException("array length exceeds byte limit ${target.position}")
+            NumericLiteralValue.optimalInteger(arraySize, args[0].position)
         }
-        in StringDatatypes -> {
-            val str = argument.strvalue!!
-            if(str.length>255)
-                throw CompilerException("string length exceeds byte limit ${argument.position}")
-            LiteralValue.optimalInteger(str.length, args[0].position)
+        DataType.STR -> {
+            val refLv = target.value as StringLiteralValue
+            if(refLv.value.length>255)
+                throw CompilerException("string length exceeds byte limit ${refLv.position}")
+            NumericLiteralValue.optimalInteger(refLv.value.length, args[0].position)
         }
         in NumericDatatypes -> throw SyntaxError("len of weird argument ${args[0]}", position)
         else -> throw CompilerException("weird datatype")
@@ -364,80 +280,87 @@ private fun builtinLen(args: List<IExpression>, position: Position, program: Pro
 }
 
 
-private fun builtinMkword(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinMkword(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 2)
         throw SyntaxError("mkword requires lsb and msb arguments", position)
     val constLsb = args[0].constValue(program) ?: throw NotConstArgumentException()
     val constMsb = args[1].constValue(program) ?: throw NotConstArgumentException()
-    val result = (constMsb.asIntegerValue!! shl 8) or constLsb.asIntegerValue!!
-    return LiteralValue(DataType.UWORD, wordvalue = result, position = position)
+    val result = (constMsb.number.toInt() shl 8) or constLsb.number.toInt()
+    return NumericLiteralValue(DataType.UWORD, result, position)
 }
 
-private fun builtinSin8(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinSin8(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("sin8 requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.BYTE, bytevalue = (127.0* sin(rad)).toShort(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.BYTE, (127.0 * sin(rad)).toShort(), position)
 }
 
-private fun builtinSin8u(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinSin8u(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("sin8u requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.UBYTE, bytevalue = (128.0+127.5*sin(rad)).toShort(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.UBYTE, (128.0 + 127.5 * sin(rad)).toShort(), position)
 }
 
-private fun builtinCos8(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinCos8(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("cos8 requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.BYTE, bytevalue = (127.0* cos(rad)).toShort(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.BYTE, (127.0 * cos(rad)).toShort(), position)
 }
 
-private fun builtinCos8u(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinCos8u(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("cos8u requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.UBYTE, bytevalue = (128.0 + 127.5*cos(rad)).toShort(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.UBYTE, (128.0 + 127.5 * cos(rad)).toShort(), position)
 }
 
-private fun builtinSin16(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinSin16(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("sin16 requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.WORD, wordvalue = (32767.0* sin(rad)).toInt(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.WORD, (32767.0 * sin(rad)).toInt(), position)
 }
 
-private fun builtinSin16u(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinSin16u(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("sin16u requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.UWORD, wordvalue = (32768.0+32767.5*sin(rad)).toInt(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.UWORD, (32768.0 + 32767.5 * sin(rad)).toInt(), position)
 }
 
-private fun builtinCos16(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinCos16(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("cos16 requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.WORD, wordvalue = (32767.0* cos(rad)).toInt(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.WORD, (32767.0 * cos(rad)).toInt(), position)
 }
 
-private fun builtinCos16u(args: List<IExpression>, position: Position, program: Program): LiteralValue {
+private fun builtinCos16u(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("cos16u requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val rad = constval.asNumericValue!!.toDouble() /256.0 * 2.0 * PI
-    return LiteralValue(DataType.UWORD, wordvalue = (32768.0+32767.5* cos(rad)).toInt(), position = position)
+    val rad = constval.number.toDouble() /256.0 * 2.0 * PI
+    return NumericLiteralValue(DataType.UWORD, (32768.0 + 32767.5 * cos(rad)).toInt(), position)
 }
 
-private fun numericLiteral(value: Number, position: Position): LiteralValue {
+private fun builtinSgn(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
+    if (args.size != 1)
+        throw SyntaxError("sgn requires one argument", position)
+    val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
+    return NumericLiteralValue(DataType.BYTE, constval.number.toDouble().sign.toShort(), position)
+}
+
+private fun numericLiteral(value: Number, position: Position): NumericLiteralValue {
     val floatNum=value.toDouble()
     val tweakedValue: Number =
             if(floatNum== floor(floatNum) && (floatNum>=-32768 && floatNum<=65535))
@@ -446,11 +369,11 @@ private fun numericLiteral(value: Number, position: Position): LiteralValue {
                 floatNum
 
     return when(tweakedValue) {
-        is Int -> LiteralValue.optimalNumeric(value.toInt(), position)
-        is Short -> LiteralValue.optimalNumeric(value.toInt(), position)
-        is Byte -> LiteralValue(DataType.UBYTE, bytevalue = value.toShort(), position = position)
-        is Double -> LiteralValue(DataType.FLOAT, floatvalue = value.toDouble(), position = position)
-        is Float -> LiteralValue(DataType.FLOAT, floatvalue = value.toDouble(), position = position)
+        is Int -> NumericLiteralValue.optimalNumeric(value.toInt(), position)
+        is Short -> NumericLiteralValue.optimalNumeric(value.toInt(), position)
+        is Byte -> NumericLiteralValue(DataType.UBYTE, value.toShort(), position)
+        is Double -> NumericLiteralValue(DataType.FLOAT, value.toDouble(), position)
+        is Float -> NumericLiteralValue(DataType.FLOAT, value.toDouble(), position)
         else -> throw FatalAstException("invalid number type ${value::class}")
     }
 }

compiler/src/prog8/optimizer/CallGraph.kt

@@ -1,19 +1,31 @@
-package prog8.optimizing
+package prog8.optimizer
 
-import prog8.ast.*
+import prog8.ast.INameScope
+import prog8.ast.Module
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.base.DataType
+import prog8.ast.base.ParentSentinel
+import prog8.ast.base.VarDeclType
+import prog8.ast.base.initvarsSubName
+import prog8.ast.expressions.FunctionCall
+import prog8.ast.expressions.IdentifierReference
+import prog8.ast.processing.IAstVisitor
+import prog8.ast.statements.*
 import prog8.compiler.loadAsmIncludeFile
 
 
-class CallGraph(private val program: Program): IAstProcessor {
+class CallGraph(private val program: Program): IAstVisitor {
 
     val modulesImporting = mutableMapOf<Module, List<Module>>().withDefault { mutableListOf() }
     val modulesImportedBy = mutableMapOf<Module, List<Module>>().withDefault { mutableListOf() }
     val subroutinesCalling = mutableMapOf<INameScope, List<Subroutine>>().withDefault { mutableListOf() }
     val subroutinesCalledBy = mutableMapOf<Subroutine, List<Node>>().withDefault { mutableListOf() }
-    val usedSymbols = mutableSetOf<IStatement>()
+    // TODO  add dataflow graph: what statements use what variables
+    val usedSymbols = mutableSetOf<Statement>()
 
     init {
-        process(program)
+        visit(program)
     }
 
     fun forAllSubroutines(scope: INameScope, sub: (s: Subroutine) -> Unit) {
@@ -28,8 +40,8 @@ class CallGraph(private val program: Program): IAstProcessor {
         findSubs(scope)
     }
 
-    override fun process(program: Program) {
-        super.process(program)
+    override fun visit(program: Program) {
+        super.visit(program)
 
         program.modules.forEach {
             it.importedBy.clear()
@@ -52,16 +64,16 @@ class CallGraph(private val program: Program): IAstProcessor {
         rootmodule.importedBy.add(rootmodule)       // don't discard root module
     }
 
-    override fun process(block: Block): IStatement {
+    override fun visit(block: Block) {
         if(block.definingModule().isLibraryModule) {
             // make sure the block is not removed
             addNodeAndParentScopes(block)
         }
 
-        return super.process(block)
+        super.visit(block)
     }
 
-    override fun process(directive: Directive): IStatement {
+    override fun visit(directive: Directive) {
         val thisModule = directive.definingModule()
         if(directive.directive=="%import") {
             val importedModule: Module = program.modules.single { it.name==directive.args[0].name }
@@ -73,47 +85,57 @@ class CallGraph(private val program: Program): IAstProcessor {
             scanAssemblyCode(asm, directive, scope)
         }
 
-        return super.process(directive)
+        super.visit(directive)
     }
 
-    override fun process(identifier: IdentifierReference): IExpression {
+    override fun visit(identifier: IdentifierReference) {
         // track symbol usage
         val target = identifier.targetStatement(this.program.namespace)
         if(target!=null) {
             addNodeAndParentScopes(target)
         }
-        return super.process(identifier)
+        super.visit(identifier)
     }
 
-    private fun addNodeAndParentScopes(stmt: IStatement) {
+    private fun addNodeAndParentScopes(stmt: Statement) {
         usedSymbols.add(stmt)
         var node: Node=stmt
         do {
-            if(node is INameScope && node is IStatement) {
+            if(node is INameScope && node is Statement) {
                 usedSymbols.add(node)
             }
             node=node.parent
         } while (node !is Module && node !is ParentSentinel)
     }
 
-    override fun process(subroutine: Subroutine): IStatement {
-        if((subroutine.name=="start" && subroutine.definingScope().name=="main")
-                || subroutine.name==initvarsSubName || subroutine.definingModule().isLibraryModule) {
+    override fun visit(subroutine: Subroutine) {
+        val alwaysKeepSubroutines = setOf(
+                Pair("main", "start"),
+                Pair("irq", "irq"),
+                Pair("prog8_lib", "init_system")
+        )
+
+        if(Pair(subroutine.definingScope().name, subroutine.name) in alwaysKeepSubroutines
+                || subroutine.name== initvarsSubName || subroutine.definingModule().isLibraryModule) {
             // make sure the entrypoint is mentioned in the used symbols
             addNodeAndParentScopes(subroutine)
         }
-        return super.process(subroutine)
+        super.visit(subroutine)
     }
 
-    override fun process(decl: VarDecl): IStatement {
-        if(decl.autoGenerated || (decl.definingModule().isLibraryModule && decl.type!=VarDeclType.VAR)) {
+    override fun visit(decl: VarDecl) {
+        if(decl.autogeneratedDontRemove || (decl.definingModule().isLibraryModule && decl.type!=VarDeclType.VAR)) {
             // make sure autogenerated vardecls are in the used symbols
             addNodeAndParentScopes(decl)
         }
-        return super.process(decl)
+
+        if(decl.datatype==DataType.STRUCT)
+            addNodeAndParentScopes(decl)
+
+        super.visit(decl)
     }
 
-    override fun process(functionCall: FunctionCall): IExpression {
+    override fun visit(functionCall: FunctionCall) {
         val otherSub = functionCall.target.targetSubroutine(program.namespace)
         if(otherSub!=null) {
             functionCall.definingSubroutine()?.let { thisSub ->
@@ -121,10 +143,10 @@ class CallGraph(private val program: Program): IAstProcessor {
                 subroutinesCalledBy[otherSub] = subroutinesCalledBy.getValue(otherSub).plus(functionCall)
             }
         }
-        return super.process(functionCall)
+        super.visit(functionCall)
     }
 
-    override fun process(functionCallStatement: FunctionCallStatement): IStatement {
+    override fun visit(functionCallStatement: FunctionCallStatement) {
         val otherSub = functionCallStatement.target.targetSubroutine(program.namespace)
         if(otherSub!=null) {
             functionCallStatement.definingSubroutine()?.let { thisSub ->
@@ -132,10 +154,10 @@ class CallGraph(private val program: Program): IAstProcessor {
                 subroutinesCalledBy[otherSub] = subroutinesCalledBy.getValue(otherSub).plus(functionCallStatement)
             }
         }
-        return super.process(functionCallStatement)
+        super.visit(functionCallStatement)
     }
 
-    override fun process(jump: Jump): IStatement {
+    override fun visit(jump: Jump) {
         val otherSub = jump.identifier?.targetSubroutine(program.namespace)
         if(otherSub!=null) {
             jump.definingSubroutine()?.let { thisSub ->
@@ -143,17 +165,22 @@ class CallGraph(private val program: Program): IAstProcessor {
                 subroutinesCalledBy[otherSub] = subroutinesCalledBy.getValue(otherSub).plus(jump)
             }
         }
-        return super.process(jump)
+        super.visit(jump)
     }
 
-    override fun process(inlineAssembly: InlineAssembly): IStatement {
+    override fun visit(structDecl: StructDecl) {
+        usedSymbols.add(structDecl)
+        usedSymbols.addAll(structDecl.statements)
+    }
+
+    override fun visit(inlineAssembly: InlineAssembly) {
         // parse inline asm for subroutine calls (jmp, jsr)
         val scope = inlineAssembly.definingScope()
         scanAssemblyCode(inlineAssembly.assembly, inlineAssembly, scope)
-        return super.process(inlineAssembly)
+        super.visit(inlineAssembly)
     }
 
-    private fun scanAssemblyCode(asm: String, context: IStatement, scope: INameScope) {
+    private fun scanAssemblyCode(asm: String, context: Statement, scope: INameScope) {
         val asmJumpRx = Regex("""[\-+a-zA-Z0-9_ \t]+(jmp|jsr)[ \t]+(\S+).*""", RegexOption.IGNORE_CASE)
         val asmRefRx = Regex("""[\-+a-zA-Z0-9_ \t]+(...)[ \t]+(\S+).*""", RegexOption.IGNORE_CASE)
         asm.lines().forEach { line ->
@@ -179,10 +206,12 @@ class CallGraph(private val program: Program): IAstProcessor {
                 if (matches2 != null) {
                     val target= matches2.groups[2]?.value
                     if (target != null && (target[0].isLetter() || target[0] == '_')) {
-                        val node = program.namespace.lookup(listOf(target.substringBefore('.')), context)
-                        if (node is Subroutine) {
-                            subroutinesCalling[scope] = subroutinesCalling.getValue(scope).plus(node)
-                            subroutinesCalledBy[node] = subroutinesCalledBy.getValue(node).plus(context)
+                        if(target.contains('.')) {
+                            val node = program.namespace.lookup(listOf(target.substringBefore('.')), context)
+                            if (node is Subroutine) {
+                                subroutinesCalling[scope] = subroutinesCalling.getValue(scope).plus(node)
+                                subroutinesCalledBy[node] = subroutinesCalledBy.getValue(node).plus(context)
+                            }
                         }
                     }
                 }

compiler/src/prog8/optimizer/ConstExprEvaluator.kt

@@ -0,0 +1,274 @@
+package prog8.optimizer
+
+import prog8.ast.base.*
+import prog8.ast.expressions.Expression
+import prog8.ast.expressions.NumericLiteralValue
+import kotlin.math.pow
+
+
+class ConstExprEvaluator {
+
+    fun evaluate(left: NumericLiteralValue, operator: String, right: NumericLiteralValue): Expression {
+        return when(operator) {
+            "+" -> plus(left, right)
+            "-" -> minus(left, right)
+            "*" -> multiply(left, right)
+            "/" -> divide(left, right)
+            "%" -> remainder(left, right)
+            "**" -> power(left, right)
+            "&" -> bitwiseand(left, right)
+            "|" -> bitwiseor(left, right)
+            "^" -> bitwisexor(left, right)
+            "and" -> logicaland(left, right)
+            "or" -> logicalor(left, right)
+            "xor" -> logicalxor(left, right)
+            "<" -> NumericLiteralValue.fromBoolean(left < right, left.position)
+            ">" -> NumericLiteralValue.fromBoolean(left > right, left.position)
+            "<=" -> NumericLiteralValue.fromBoolean(left <= right, left.position)
+            ">=" -> NumericLiteralValue.fromBoolean(left >= right, left.position)
+            "==" -> NumericLiteralValue.fromBoolean(left == right, left.position)
+            "!=" -> NumericLiteralValue.fromBoolean(left != right, left.position)
+            "<<" -> shiftedleft(left, right)
+            ">>" -> shiftedright(left, right)
+            else -> throw FatalAstException("const evaluation for invalid operator $operator")
+        }
+    }
+
+    private fun shiftedright(left: NumericLiteralValue, amount: NumericLiteralValue): Expression {
+        if(left.type !in IntegerDatatypes || amount.type !in IntegerDatatypes)
+            throw ExpressionError("cannot compute $left >> $amount", left.position)
+        val result =
+                if(left.type== DataType.UBYTE || left.type== DataType.UWORD)
+                    left.number.toInt().ushr(amount.number.toInt())
+                else
+                    left.number.toInt().shr(amount.number.toInt())
+        return NumericLiteralValue(left.type, result, left.position)
+    }
+
+    private fun shiftedleft(left: NumericLiteralValue, amount: NumericLiteralValue): Expression {
+        if(left.type !in IntegerDatatypes || amount.type !in IntegerDatatypes)
+            throw ExpressionError("cannot compute $left << $amount", left.position)
+        val result = left.number.toInt().shl(amount.number.toInt())
+        return NumericLiteralValue(left.type, result, left.position)
+    }
+
+    private fun logicalxor(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
+        val error = "cannot compute $left locical-bitxor $right"
+        return when (left.type) {
+            in IntegerDatatypes -> when (right.type) {
+                in IntegerDatatypes -> NumericLiteralValue.fromBoolean((left.number.toInt() != 0) xor (right.number.toInt() != 0), left.position)
+                DataType.FLOAT -> NumericLiteralValue.fromBoolean((left.number.toInt() != 0) xor (right.number.toDouble() != 0.0), left.position)
+                else -> throw ExpressionError(error, left.position)
+            }
+            DataType.FLOAT -> when (right.type) {
+                in IntegerDatatypes -> NumericLiteralValue.fromBoolean((left.number.toDouble() != 0.0) xor (right.number.toInt() != 0), left.position)
+                DataType.FLOAT -> NumericLiteralValue.fromBoolean((left.number.toDouble() != 0.0) xor (right.number.toDouble() != 0.0), left.position)
+                else -> throw ExpressionError(error, left.position)
+            }
+            else -> throw ExpressionError(error, left.position)
+        }
+    }
+
+    private fun logicalor(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
+        val error = "cannot compute $left locical-or $right"
+        return when (left.type) {
+            in IntegerDatatypes -> when (right.type) {
+                in IntegerDatatypes -> NumericLiteralValue.fromBoolean(left.number.toInt() != 0 || right.number.toInt() != 0, left.position)
+                DataType.FLOAT -> NumericLiteralValue.fromBoolean(left.number.toInt() != 0 || right.number.toDouble() != 0.0, left.position)
+                else -> throw ExpressionError(error, left.position)
+            }
+            DataType.FLOAT -> when (right.type) {
+                in IntegerDatatypes -> NumericLiteralValue.fromBoolean(left.number.toDouble() != 0.0 || right.number.toInt() != 0, left.position)
+                DataType.FLOAT -> NumericLiteralValue.fromBoolean(left.number.toDouble() != 0.0 || right.number.toDouble() != 0.0, left.position)
+                else -> throw ExpressionError(error, left.position)
+            }
+            else -> throw ExpressionError(error, left.position)
+        }
+    }
+
+    private fun logicaland(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
+        val error = "cannot compute $left locical-and $right"
+        return when (left.type) {
+            in IntegerDatatypes -> when (right.type) {
+                in IntegerDatatypes -> NumericLiteralValue.fromBoolean(left.number.toInt() != 0 && right.number.toInt() != 0, left.position)
+                DataType.FLOAT -> NumericLiteralValue.fromBoolean(left.number.toInt() != 0 && right.number.toDouble() != 0.0, left.position)
+                else -> throw ExpressionError(error, left.position)
+            }
+            DataType.FLOAT -> when (right.type) {
+                in IntegerDatatypes -> NumericLiteralValue.fromBoolean(left.number.toDouble() != 0.0 && right.number.toInt() != 0, left.position)
+                DataType.FLOAT -> NumericLiteralValue.fromBoolean(left.number.toDouble() != 0.0 && right.number.toDouble() != 0.0, left.position)
+                else -> throw ExpressionError(error, left.position)
+            }
+            else -> throw ExpressionError(error, left.position)
+        }
+    }
+
+    private fun bitwisexor(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
+        if(left.type== DataType.UBYTE) {
+            if(right.type in IntegerDatatypes) {
+                return NumericLiteralValue(DataType.UBYTE, (left.number.toInt() xor (right.number.toInt() and 255)).toShort(), left.position)
+            }
+        } else if(left.type== DataType.UWORD) {
+            if(right.type in IntegerDatatypes) {
+                return NumericLiteralValue(DataType.UWORD, left.number.toInt() xor right.number.toInt(), left.position)
+            }
+        }
+        throw ExpressionError("cannot calculate $left ^ $right", left.position)
+    }
+
+    private fun bitwiseor(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
+        if(left.type== DataType.UBYTE) {
+            if(right.type in IntegerDatatypes) {
+                return NumericLiteralValue(DataType.UBYTE, (left.number.toInt() or (right.number.toInt() and 255)).toShort(), left.position)
+            }
+        } else if(left.type== DataType.UWORD) {
+            if(right.type in IntegerDatatypes) {
+                return NumericLiteralValue(DataType.UWORD, left.number.toInt() or right.number.toInt(), left.position)
+            }
+        }
+        throw ExpressionError("cannot calculate $left | $right", left.position)
+    }
+
+    private fun bitwiseand(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
+        if(left.type== DataType.UBYTE) {
+            if(right.type in IntegerDatatypes) {
+                return NumericLiteralValue(DataType.UBYTE, (left.number.toInt() or (right.number.toInt() and 255)).toShort(), left.position)
+            }
+        } else if(left.type== DataType.UWORD) {
+            if(right.type in IntegerDatatypes) {
+                return NumericLiteralValue(DataType.UWORD, left.number.toInt() or right.number.toInt(), left.position)
+            }
+        }
+        throw ExpressionError("cannot calculate $left & $right", left.position)
+    }
+
+    private fun power(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
+        val error = "cannot calculate $left ** $right"
+        return when (left.type) {
+            in IntegerDatatypes -> when (right.type) {
+                in IntegerDatatypes -> NumericLiteralValue.optimalNumeric(left.number.toInt().toDouble().pow(right.number.toInt()), left.position)
+                DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toInt().toDouble().pow(right.number.toDouble()), left.position)
+                else -> throw ExpressionError(error, left.position)
+            }
+            DataType.FLOAT -> when (right.type) {
+                in IntegerDatatypes -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble().pow(right.number.toInt()), left.position)
+                DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble().pow(right.number.toDouble()), left.position)
+                else -> throw ExpressionError(error, left.position)
+            }
+            else -> throw ExpressionError(error, left.position)
+        }
+    }
+
+    private fun plus(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
+        val error = "cannot add $left and $right"
+        return when (left.type) {
+            in IntegerDatatypes -> when (right.type) {
+                in IntegerDatatypes -> NumericLiteralValue.optimalNumeric(left.number.toInt() + right.number.toInt(), left.position)
+                DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toInt() + right.number.toDouble(), left.position)
+                else -> throw ExpressionError(error, left.position)
+            }
+            DataType.FLOAT -> when (right.type) {
+                in IntegerDatatypes -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble() + right.number.toInt(), left.position)
+                DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble() + right.number.toDouble(), left.position)
+                else -> throw ExpressionError(error, left.position)
+            }
+            else -> throw ExpressionError(error, left.position)
+        }
+    }
+
+    private fun minus(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
+        val error = "cannot subtract $left and $right"
+        return when (left.type) {
+            in IntegerDatatypes -> when (right.type) {
+                in IntegerDatatypes -> NumericLiteralValue.optimalNumeric(left.number.toInt() - right.number.toInt(), left.position)
+                DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toInt() - right.number.toDouble(), left.position)
+                else -> throw ExpressionError(error, left.position)
+            }
+            DataType.FLOAT -> when (right.type) {
+                in IntegerDatatypes -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble() - right.number.toInt(), left.position)
+                DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble() - right.number.toDouble(), left.position)
+                else -> throw ExpressionError(error, left.position)
+            }
+            else -> throw ExpressionError(error, left.position)
+        }
+    }
+
+    private fun multiply(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
+        val error = "cannot multiply ${left.type} and ${right.type}"
+        return when (left.type) {
+            in IntegerDatatypes -> when (right.type) {
+                in IntegerDatatypes -> NumericLiteralValue.optimalNumeric(left.number.toInt() * right.number.toInt(), left.position)
+                DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toInt() * right.number.toDouble(), left.position)
+                else -> throw ExpressionError(error, left.position)
+            }
+            DataType.FLOAT -> when (right.type) {
+                in IntegerDatatypes -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble() * right.number.toInt(), left.position)
+                DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toDouble() * right.number.toDouble(), left.position)
+                else -> throw ExpressionError(error, left.position)
+            }
+            else -> throw ExpressionError(error, left.position)
+        }
+    }
+
+    private fun divideByZeroError(pos: Position): Unit =
+            throw ExpressionError("division by zero", pos)
+
+    private fun divide(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
+        val error = "cannot divide $left by $right"
+        return when (left.type) {
+            in IntegerDatatypes -> when (right.type) {
+                in IntegerDatatypes -> {
+                    if(right.number.toInt()==0) divideByZeroError(right.position)
+                    val result: Int = left.number.toInt() / right.number.toInt()
+                    NumericLiteralValue.optimalNumeric(result, left.position)
+                }
+                DataType.FLOAT -> {
+                    if(right.number.toDouble()==0.0) divideByZeroError(right.position)
+                    NumericLiteralValue(DataType.FLOAT, left.number.toInt() / right.number.toDouble(), left.position)
+                }
+                else -> throw ExpressionError(error, left.position)
+            }
+            DataType.FLOAT -> when (right.type) {
+                in IntegerDatatypes -> {
+                    if(right.number.toInt()==0) divideByZeroError(right.position)
+                    NumericLiteralValue(DataType.FLOAT, left.number.toDouble() / right.number.toInt(), left.position)
+                }
+                DataType.FLOAT -> {
+                    if(right.number.toDouble()==0.0) divideByZeroError(right.position)
+                    NumericLiteralValue(DataType.FLOAT, left.number.toDouble() / right.number.toDouble(), left.position)
+                }
+                else -> throw ExpressionError(error, left.position)
+            }
+            else -> throw ExpressionError(error, left.position)
+        }
+    }
+
+    private fun remainder(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
+        val error = "cannot compute remainder of $left by $right"
+        return when (left.type) {
+            in IntegerDatatypes -> when (right.type) {
+                in IntegerDatatypes -> {
+                    if(right.number.toInt()==0) divideByZeroError(right.position)
+                    NumericLiteralValue.optimalNumeric(left.number.toInt().toDouble() % right.number.toInt().toDouble(), left.position)
+                }
+                DataType.FLOAT -> {
+                    if(right.number.toDouble()==0.0) divideByZeroError(right.position)
+                    NumericLiteralValue(DataType.FLOAT, left.number.toInt() % right.number.toDouble(), left.position)
+                }
+                else -> throw ExpressionError(error, left.position)
+            }
+            DataType.FLOAT -> when (right.type) {
+                in IntegerDatatypes -> {
+                    if(right.number.toInt()==0) divideByZeroError(right.position)
+                    NumericLiteralValue(DataType.FLOAT, left.number.toDouble() % right.number.toInt(), left.position)
+                }
+                DataType.FLOAT -> {
+                    if(right.number.toDouble()==0.0) divideByZeroError(right.position)
+                    NumericLiteralValue(DataType.FLOAT, left.number.toDouble() % right.number.toDouble(), left.position)
+                }
+                else -> throw ExpressionError(error, left.position)
+            }
+            else -> throw ExpressionError(error, left.position)
+        }
+    }
+}

compiler/src/prog8/optimizer/ConstantFolding.kt

@@ -1,18 +1,21 @@
-package prog8.optimizing
+package prog8.optimizer
 
-import prog8.ast.*
-import prog8.compiler.CompilerException
-import prog8.compiler.HeapValues
-import prog8.compiler.IntegerOrAddressOf
-import prog8.compiler.target.c64.FLOAT_MAX_NEGATIVE
-import prog8.compiler.target.c64.FLOAT_MAX_POSITIVE
+import prog8.ast.IFunctionCall
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.processing.IAstModifyingVisitor
+import prog8.ast.processing.fixupArrayEltDatatypesFromVardecl
+import prog8.ast.processing.fixupArrayEltDatatypes
+import prog8.ast.statements.*
+import prog8.compiler.target.CompilationTarget
+import prog8.functions.BuiltinFunctions
 import kotlin.math.floor
 
 
-class ConstantFolding(private val program: Program) : IAstProcessor {
+class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
     var optimizationsDone: Int = 0
     var errors : MutableList<AstException> = mutableListOf()
-
     private val reportedErrorMessages = mutableSetOf<String>()
 
     fun addError(x: AstException) {
@@ -23,30 +26,27 @@ class ConstantFolding(private val program: Program) : IAstProcessor {
         }
     }
 
-    override fun process(decl: VarDecl): IStatement {
+    override fun visit(decl: VarDecl): Statement {
         // the initializer value can't refer to the variable itself (recursive definition)
-        if(decl.value?.referencesIdentifier(decl.name) == true || decl.arraysize?.index?.referencesIdentifier(decl.name) == true) {
+        // TODO: use call tree for this?
+        if(decl.value?.referencesIdentifiers(decl.name) == true || decl.arraysize?.index?.referencesIdentifiers(decl.name) == true) {
             errors.add(ExpressionError("recursive var declaration", decl.position))
             return decl
         }
 
         if(decl.type==VarDeclType.CONST || decl.type==VarDeclType.VAR) {
-            val litval = decl.value as? LiteralValue
-            if(litval!=null && litval.isArray && litval.heapId!=null)
-                fixupArrayTypeOnHeap(decl, litval)
-
             if(decl.isArray){
-                // for arrays that have no size specifier (or a non-constant one) attempt to deduce the size
                 if(decl.arraysize==null) {
-                    val arrayval = (decl.value as? LiteralValue)?.arrayvalue
+                    // for arrays that have no size specifier (or a non-constant one) attempt to deduce the size
+                    val arrayval = decl.value as? ArrayLiteralValue
                     if(arrayval!=null) {
-                        decl.arraysize = ArrayIndex(LiteralValue.optimalInteger(arrayval.size, decl.position), decl.position)
+                        decl.arraysize = ArrayIndex(NumericLiteralValue.optimalInteger(arrayval.value.size, decl.position), decl.position)
                         optimizationsDone++
                     }
                 }
                 else if(decl.arraysize?.size()==null) {
-                    val size = decl.arraysize!!.index.process(this)
-                    if(size is LiteralValue) {
+                    val size = decl.arraysize!!.index.accept(this)
+                    if(size is NumericLiteralValue) {
                         decl.arraysize = ArrayIndex(size, decl.position)
                         optimizationsDone++
                     }
@@ -56,141 +56,139 @@ class ConstantFolding(private val program: Program) : IAstProcessor {
             when(decl.datatype) {
                 DataType.FLOAT -> {
                     // vardecl: for scalar float vars, promote constant integer initialization values to floats
-                    if (litval != null && litval.type in IntegerDatatypes) {
-                        val newValue = LiteralValue(DataType.FLOAT, floatvalue = litval.asNumericValue!!.toDouble(), position = litval.position)
+                    val litval = decl.value as? NumericLiteralValue
+                    if (litval!=null && litval.type in IntegerDatatypes) {
+                        val newValue = NumericLiteralValue(DataType.FLOAT, litval.number.toDouble(), litval.position)
                         decl.value = newValue
                         optimizationsDone++
-                        return decl
+                        return super.visit(decl)
                     }
                 }
                 DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W -> {
+                    val numericLv = decl.value as? NumericLiteralValue
                     val rangeExpr = decl.value as? RangeExpr
                     if(rangeExpr!=null) {
-                        // convert the initializer range expression to an actual array (will be put on heap later)
+                        // convert the initializer range expression to an actual array
                         val declArraySize = decl.arraysize?.size()
                         if(declArraySize!=null && declArraySize!=rangeExpr.size())
                             errors.add(ExpressionError("range expression size doesn't match declared array size", decl.value?.position!!))
                         val constRange = rangeExpr.toConstantIntegerRange()
                         if(constRange!=null) {
-                            val eltType = rangeExpr.inferType(program)!!
+                            val eltType = rangeExpr.inferType(program).typeOrElse(DataType.UBYTE)
                             if(eltType in ByteDatatypes) {
-                                decl.value = LiteralValue(decl.datatype,
-                                        arrayvalue = constRange.map { LiteralValue(eltType, bytevalue=it.toShort(), position = decl.value!!.position ) }
-                                                .toTypedArray(), position=decl.value!!.position)
+                                decl.value = ArrayLiteralValue(decl.datatype,
+                                        constRange.map { NumericLiteralValue(eltType, it.toShort(), decl.value!!.position) }.toTypedArray(),
+                                        position = decl.value!!.position)
                             } else {
-                                decl.value = LiteralValue(decl.datatype,
-                                        arrayvalue = constRange.map { LiteralValue(eltType, wordvalue= it, position = decl.value!!.position ) }
-                                                .toTypedArray(), position=decl.value!!.position)
+                                decl.value = ArrayLiteralValue(decl.datatype,
+                                        constRange.map { NumericLiteralValue(eltType, it, decl.value!!.position) }.toTypedArray(),
+                                        position = decl.value!!.position)
                             }
                             decl.value!!.linkParents(decl)
                             optimizationsDone++
-                            return decl
+                            return super.visit(decl)
                         }
                     }
-                    if(litval?.type==DataType.FLOAT)
-                        errors.add(ExpressionError("arraysize requires only integers here", litval.position))
+                    if(numericLv!=null && numericLv.type== DataType.FLOAT)
+                        errors.add(ExpressionError("arraysize requires only integers here", numericLv.position))
                     val size = decl.arraysize?.size() ?: return decl
-                    if ((litval==null || !litval.isArray) && rangeExpr==null) {
+                    if (rangeExpr==null && numericLv!=null) {
                         // arraysize initializer is empty or a single int, and we know the size; create the arraysize.
-                        val fillvalue = if (litval == null) 0 else litval.asIntegerValue ?: 0
+                        val fillvalue = numericLv.number.toInt()
                         when(decl.datatype){
                             DataType.ARRAY_UB -> {
                                 if(fillvalue !in 0..255)
-                                    errors.add(ExpressionError("ubyte value overflow", litval?.position ?: decl.position))
+                                    errors.add(ExpressionError("ubyte value overflow", numericLv.position))
                             }
                             DataType.ARRAY_B -> {
                                 if(fillvalue !in -128..127)
-                                    errors.add(ExpressionError("byte value overflow", litval?.position ?: decl.position))
+                                    errors.add(ExpressionError("byte value overflow", numericLv.position))
                             }
                             DataType.ARRAY_UW -> {
                                 if(fillvalue !in 0..65535)
-                                    errors.add(ExpressionError("uword value overflow", litval?.position ?: decl.position))
+                                    errors.add(ExpressionError("uword value overflow", numericLv.position))
                             }
                             DataType.ARRAY_W -> {
                                 if(fillvalue !in -32768..32767)
-                                    errors.add(ExpressionError("word value overflow", litval?.position ?: decl.position))
+                                    errors.add(ExpressionError("word value overflow", numericLv.position))
                             }
                             else -> {}
                         }
-                        val heapId = program.heap.addIntegerArray(decl.datatype, Array(size) { IntegerOrAddressOf(fillvalue, null) })
-                        decl.value = LiteralValue(decl.datatype, initHeapId = heapId, position = litval?.position ?: decl.position)
+                        // create the array itself, filled with the fillvalue.
+                        val array = Array(size) {fillvalue}.map { NumericLiteralValue.optimalInteger(it, numericLv.position) as Expression}.toTypedArray()
+                        val refValue = ArrayLiteralValue(decl.datatype, array, position = numericLv.position)
+                        decl.value = refValue
+                        refValue.parent=decl
                         optimizationsDone++
-                        return decl
+                        return super.visit(decl)
                     }
                 }
                 DataType.ARRAY_F  -> {
                     val size = decl.arraysize?.size() ?: return decl
-                    if (litval==null || !litval.isArray) {
-                        // arraysize initializer is empty or a single int, and we know the size; create the arraysize.
-                        val fillvalue = if (litval == null) 0.0 else litval.asNumericValue?.toDouble() ?: 0.0
-                        if(fillvalue< FLOAT_MAX_NEGATIVE || fillvalue> FLOAT_MAX_POSITIVE)
-                            errors.add(ExpressionError("float value overflow", litval?.position ?: decl.position))
+                    val litval = decl.value as? NumericLiteralValue
+                    if(litval==null) {
+                        // there's no initialization value, but the size is known, so we're ok.
+                        return super.visit(decl)
+                    } else {
+                        // arraysize initializer is a single int, and we know the size.
+                        val fillvalue = litval.number.toDouble()
+                        if (fillvalue < CompilationTarget.machine.FLOAT_MAX_NEGATIVE || fillvalue > CompilationTarget.machine.FLOAT_MAX_POSITIVE)
+                            errors.add(ExpressionError("float value overflow", litval.position))
                         else {
-                            val heapId = program.heap.addDoublesArray(DoubleArray(size) { fillvalue })
-                            decl.value = LiteralValue(DataType.ARRAY_F, initHeapId = heapId, position = litval?.position ?: decl.position)
+                            // create the array itself, filled with the fillvalue.
+                            val array = Array(size) {fillvalue}.map { NumericLiteralValue(DataType.FLOAT, it, litval.position) as Expression}.toTypedArray()
+                            val refValue = ArrayLiteralValue(DataType.ARRAY_F, array, position = litval.position)
+                            decl.value = refValue
+                            refValue.parent=decl
                             optimizationsDone++
-                            return decl
+                            return super.visit(decl)
                         }
                     }
                 }
                 else -> {
                     // nothing to do for this type
+                    // this includes strings and structs
                 }
             }
         }
 
-        return super.process(decl)
-    }
-
-    private fun fixupArrayTypeOnHeap(decl: VarDecl, litval: LiteralValue) {
-        // fix the type of the array value that's on the heap, to match the vardecl.
-        // notice that checking the bounds of the actual values is not done here, but in the AstChecker later.
-
-        if(decl.datatype==litval.type)
-            return   // already correct datatype
-        val heapId = litval.heapId ?: throw FatalAstException("expected array to be on heap $litval")
-        val array = program.heap.get(heapId)
-        when(decl.datatype) {
-            DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W -> {
-                if(array.array!=null) {
-                    program.heap.update(heapId, HeapValues.HeapValue(decl.datatype, null, array.array, null))
-                    decl.value = LiteralValue(decl.datatype, initHeapId=heapId, position = litval.position)
-                }
-            }
-            DataType.ARRAY_F -> {
-                if(array.array!=null) {
-                    // convert a non-float array to floats
-                    val doubleArray = array.array.map { it.integer!!.toDouble() }.toDoubleArray()
-                    program.heap.update(heapId, HeapValues.HeapValue(DataType.ARRAY_F, null, null, doubleArray))
-                    decl.value = LiteralValue(decl.datatype, initHeapId = heapId, position = litval.position)
-                }
-            }
-            else -> throw FatalAstException("invalid array vardecl type ${decl.datatype}")
-        }
+        return super.visit(decl)
     }
 
     /**
      * replace identifiers that refer to const value, with the value itself (if it's a simple type)
      */
-    override fun process(identifier: IdentifierReference): IExpression {
+    override fun visit(identifier: IdentifierReference): Expression {
+        // don't replace when it's an assignment target or loop variable
+        if(identifier.parent is AssignTarget)
+            return identifier
+        var forloop = identifier.parent as? ForLoop
+        if(forloop==null)
+            forloop = identifier.parent.parent as? ForLoop
+        if(forloop!=null && identifier===forloop.loopVar)
+            return identifier
+
         return try {
             val cval = identifier.constValue(program) ?: return identifier
-            return if(cval.isNumeric) {
-                val copy = LiteralValue(cval.type, cval.bytevalue, cval.wordvalue, cval.floatvalue, null, cval.arrayvalue, position = identifier.position)
-                copy.parent = identifier.parent
-                copy
-            } else
-                identifier
+            return when (cval.type) {
+                in NumericDatatypes -> {
+                    val copy = NumericLiteralValue(cval.type, cval.number, identifier.position)
+                    copy.parent = identifier.parent
+                    copy
+                }
+                in PassByReferenceDatatypes -> throw FatalAstException("pass-by-reference type should not be considered a constant")
+                else -> identifier
+            }
         } catch (ax: AstException) {
             addError(ax)
             identifier
         }
     }
 
-    override fun process(functionCall: FunctionCall): IExpression {
+    override fun visit(functionCall: FunctionCall): Expression {
+        super.visit(functionCall)
+        typeCastConstArguments(functionCall)
         return try {
-            super.process(functionCall)
-            typeCastConstArguments(functionCall)
             functionCall.constValue(program) ?: functionCall
         } catch (ax: AstException) {
             addError(ax)
@@ -198,93 +196,95 @@ class ConstantFolding(private val program: Program) : IAstProcessor {
         }
     }
 
-    override fun process(functionCallStatement: FunctionCallStatement): IStatement {
-        super.process(functionCallStatement)
+    override fun visit(functionCallStatement: FunctionCallStatement): Statement {
+        super.visit(functionCallStatement)
         typeCastConstArguments(functionCallStatement)
         return functionCallStatement
     }
 
     private fun typeCastConstArguments(functionCall: IFunctionCall) {
+        if(functionCall.target.nameInSource.size==1) {
+            val builtinFunction = BuiltinFunctions[functionCall.target.nameInSource.single()]
+            if(builtinFunction!=null) {
+                // match the arguments of a builtin function signature.
+                for(arg in functionCall.args.withIndex().zip(builtinFunction.parameters)) {
+                    val possibleDts = arg.second.possibleDatatypes
+                    val argConst = arg.first.value.constValue(program)
+                    if(argConst!=null && argConst.type !in possibleDts) {
+                        val convertedValue = argConst.cast(possibleDts.first())
+                        functionCall.args[arg.first.index] = convertedValue
+                        optimizationsDone++
+                    }
+                }
+                return
+            }
+        }
+        // match the arguments of a subroutine.
         val subroutine = functionCall.target.targetSubroutine(program.namespace)
         if(subroutine!=null) {
             // if types differ, try to typecast constant arguments to the function call to the desired data type of the parameter
-            for(arg in functionCall.arglist.withIndex().zip(subroutine.parameters)) {
+            for(arg in functionCall.args.withIndex().zip(subroutine.parameters)) {
                 val expectedDt = arg.second.type
                 val argConst = arg.first.value.constValue(program)
                 if(argConst!=null && argConst.type!=expectedDt) {
-                    val convertedValue = argConst.intoDatatype(expectedDt)
-                    if(convertedValue!=null) {
-                        functionCall.arglist[arg.first.index] = convertedValue
-                        optimizationsDone++
-                    }
+                    val convertedValue = argConst.cast(expectedDt)
+                    functionCall.args[arg.first.index] = convertedValue
+                    optimizationsDone++
                 }
             }
         }
     }
 
-    override fun process(memread: DirectMemoryRead): IExpression {
+    override fun visit(memread: DirectMemoryRead): Expression {
         // @( &thing )  -->  thing
         val addrOf = memread.addressExpression as? AddressOf
         if(addrOf!=null)
-            return super.process(addrOf.identifier)
-        return super.process(memread)
-    }
-
-    override fun process(memwrite: DirectMemoryWrite): IExpression {
-        // @( &thing )  -->  thing
-        val addrOf = memwrite.addressExpression as? AddressOf
-        if(addrOf!=null)
-            return super.process(addrOf.identifier)
-        return super.process(memwrite)
+            return super.visit(addrOf.identifier)
+        return super.visit(memread)
     }
 
     /**
-     * Try to process a unary prefix expression.
+     * Try to accept a unary prefix expression.
      * Compile-time constant sub expressions will be evaluated on the spot.
      * For instance, the expression for "- 4.5" will be optimized into the float literal -4.5
      */
-    override fun process(expr: PrefixExpression): IExpression {
+    override fun visit(expr: PrefixExpression): Expression {
         return try {
-            super.process(expr)
+            val prefixExpr=super.visit(expr)
+            if(prefixExpr !is PrefixExpression)
+                return prefixExpr
 
-            val subexpr = expr.expression
-            if (subexpr is LiteralValue) {
-                // process prefixed literal values (such as -3, not true)
-                return when {
-                    expr.operator == "+" -> subexpr
-                    expr.operator == "-" -> when {
-                        subexpr.asIntegerValue!= null -> {
+            val subexpr = prefixExpr.expression
+            if (subexpr is NumericLiteralValue) {
+                // accept prefixed literal values (such as -3, not true)
+                return when (prefixExpr.operator) {
+                    "+" -> subexpr
+                    "-" -> when (subexpr.type) {
+                        in IntegerDatatypes -> {
                             optimizationsDone++
-                            LiteralValue.optimalNumeric(-subexpr.asIntegerValue, subexpr.position)
+                            NumericLiteralValue.optimalNumeric(-subexpr.number.toInt(), subexpr.position)
                         }
-                        subexpr.floatvalue != null -> {
+                        DataType.FLOAT -> {
                             optimizationsDone++
-                            LiteralValue(DataType.FLOAT, floatvalue = -subexpr.floatvalue, position = subexpr.position)
+                            NumericLiteralValue(DataType.FLOAT, -subexpr.number.toDouble(), subexpr.position)
                         }
                         else -> throw ExpressionError("can only take negative of int or float", subexpr.position)
                     }
-                    expr.operator == "~" -> when {
-                        subexpr.asIntegerValue != null -> {
+                    "~" -> when (subexpr.type) {
+                        in IntegerDatatypes -> {
                             optimizationsDone++
-                            LiteralValue.optimalNumeric(subexpr.asIntegerValue.inv(), subexpr.position)
+                            NumericLiteralValue.optimalNumeric(subexpr.number.toInt().inv(), subexpr.position)
                         }
                         else -> throw ExpressionError("can only take bitwise inversion of int", subexpr.position)
                     }
-                    expr.operator == "not" -> when {
-                        subexpr.asIntegerValue != null -> {
-                            optimizationsDone++
-                            LiteralValue.fromBoolean(subexpr.asIntegerValue == 0, subexpr.position)
-                        }
-                        subexpr.floatvalue != null -> {
-                            optimizationsDone++
-                            LiteralValue.fromBoolean(subexpr.floatvalue == 0.0, subexpr.position)
-                        }
-                        else -> throw ExpressionError("can not take logical not of $subexpr", subexpr.position)
+                    "not" -> {
+                        optimizationsDone++
+                        NumericLiteralValue.fromBoolean(subexpr.number.toDouble() == 0.0, subexpr.position)
                     }
-                    else -> throw ExpressionError(expr.operator, subexpr.position)
+                    else -> throw ExpressionError(prefixExpr.operator, subexpr.position)
                 }
             }
-            return expr
+            return prefixExpr
         } catch (ax: AstException) {
             addError(ax)
             expr
@@ -292,7 +292,7 @@ class ConstantFolding(private val program: Program) : IAstProcessor {
     }
 
     /**
-     * Try to process a binary expression.
+     * Try to accept a binary expression.
      * Compile-time constant sub expressions will be evaluated on the spot.
      * For instance, "9 * (4 + 2)" will be optimized into the integer literal 54.
      *
@@ -308,9 +308,14 @@ class ConstantFolding(private val program: Program) : IAstProcessor {
      *        (X / c1) * c2  ->  X / (c2/c1)
      *        (X + c1) - c2  ->  X + (c1-c2)
      */
-    override fun process(expr: BinaryExpression): IExpression {
+    override fun visit(expr: BinaryExpression): Expression {
         return try {
-            super.process(expr)
+            super.visit(expr)
+
+            if(expr.left is StringLiteralValue || expr.left is ArrayLiteralValue
+                    || expr.right is StringLiteralValue || expr.right is ArrayLiteralValue)
+                throw FatalAstException("binexpr with reference litval instead of numeric")
+
             val leftconst = expr.left.constValue(program)
             val rightconst = expr.right.constValue(program)
 
@@ -331,12 +336,13 @@ class ConstantFolding(private val program: Program) : IAstProcessor {
             }
 
             // const fold when both operands are a const
-            val evaluator = ConstExprEvaluator()
             return when {
                 leftconst != null && rightconst != null -> {
                     optimizationsDone++
+                    val evaluator = ConstExprEvaluator()
                     evaluator.evaluate(leftconst, expr.operator, rightconst)
                 }
+
                 else -> expr
             }
         } catch (ax: AstException) {
@@ -350,9 +356,9 @@ class ConstantFolding(private val program: Program) : IAstProcessor {
                                        leftIsConst: Boolean,
                                        rightIsConst: Boolean,
                                        subleftIsConst: Boolean,
-                                       subrightIsConst: Boolean): IExpression
+                                       subrightIsConst: Boolean): Expression
     {
-        // @todo this implements only a small set of possible reorderings for now
+        // todo: this implements only a small set of possible reorderings at this time
         if(expr.operator==subExpr.operator) {
             // both operators are the isSameAs.
             // If + or *,  we can simply swap the const of expr and Var in subexpr.
@@ -385,7 +391,7 @@ class ConstantFolding(private val program: Program) : IAstProcessor {
                         expr
                     } else
                         BinaryExpression(
-                                BinaryExpression(expr.left, if(expr.operator=="-") "+" else "*", subExpr.right, subExpr.position),
+                                BinaryExpression(expr.left, if (expr.operator == "-") "+" else "*", subExpr.right, subExpr.position),
                                 expr.operator, subExpr.left, expr.position)
                 } else {
                     return if(subleftIsConst) {
@@ -394,7 +400,7 @@ class ConstantFolding(private val program: Program) : IAstProcessor {
                     } else
                         BinaryExpression(
                                 subExpr.left, expr.operator,
-                                BinaryExpression(expr.right, if(expr.operator=="-") "+" else "*", subExpr.right, subExpr.position),
+                                BinaryExpression(expr.right, if (expr.operator == "-") "+" else "*", subExpr.right, subExpr.position),
                                 expr.position)
                 }
             }
@@ -537,177 +543,166 @@ class ConstantFolding(private val program: Program) : IAstProcessor {
         }
     }
 
-    override fun process(forLoop: ForLoop): IStatement {
+    override fun visit(forLoop: ForLoop): Statement {
 
-        fun adjustRangeDt(rangeFrom: LiteralValue, targetDt: DataType, rangeTo: LiteralValue, stepLiteral: LiteralValue?, range: RangeExpr): RangeExpr {
-            val newFrom = rangeFrom.intoDatatype(targetDt)
-            val newTo = rangeTo.intoDatatype(targetDt)
-            if (newFrom != null && newTo != null) {
-                val newStep: IExpression =
-                        if (stepLiteral != null) (stepLiteral.intoDatatype(targetDt) ?: stepLiteral) else range.step
-                return RangeExpr(newFrom, newTo, newStep, range.position)
+        fun adjustRangeDt(rangeFrom: NumericLiteralValue, targetDt: DataType, rangeTo: NumericLiteralValue, stepLiteral: NumericLiteralValue?, range: RangeExpr): RangeExpr {
+            val newFrom: NumericLiteralValue
+            val newTo: NumericLiteralValue
+            try {
+                newFrom = rangeFrom.cast(targetDt)
+                newTo = rangeTo.cast(targetDt)
+            } catch (x: ExpressionError) {
+                return range
+            }
+            val newStep: Expression = try {
+                stepLiteral?.cast(targetDt)?: range.step
+            } catch(ee: ExpressionError) {
+                range.step
+            }
+            return RangeExpr(newFrom, newTo, newStep, range.position)
+        }
+
+        val forLoop2 = super.visit(forLoop) as ForLoop
+
+        // check if we need to adjust an array literal to the loop variable's datatype
+        val array = forLoop2.iterable as? ArrayLiteralValue
+        if(array!=null) {
+            val loopvarDt: DataType = when {
+                forLoop.loopVar!=null -> forLoop.loopVar!!.inferType(program).typeOrElse(DataType.UBYTE)
+                forLoop.loopRegister!=null -> DataType.UBYTE
+                else -> throw FatalAstException("weird for loop")
+            }
+
+            val arrayType = when(loopvarDt) {
+                DataType.UBYTE -> DataType.ARRAY_UB
+                DataType.BYTE -> DataType.ARRAY_B
+                DataType.UWORD -> DataType.ARRAY_UW
+                DataType.WORD -> DataType.ARRAY_W
+                DataType.FLOAT -> DataType.ARRAY_F
+                else -> throw FatalAstException("invalid array elt type")
+            }
+            val array2 = array.cast(arrayType)
+            if(array2!=null && array2!==array) {
+                forLoop2.iterable = array2
+                array2.linkParents(forLoop2)
             }
-            return range
         }
 
         // adjust the datatype of a range expression in for loops to the loop variable.
-        val resultStmt = super.process(forLoop) as ForLoop
-        val iterableRange = resultStmt.iterable as? RangeExpr ?: return resultStmt
-        val rangeFrom = iterableRange.from as? LiteralValue
-        val rangeTo = iterableRange.to as? LiteralValue
-        if(rangeFrom==null || rangeTo==null) return resultStmt
+        val iterableRange = forLoop2.iterable as? RangeExpr ?: return forLoop2
+        val rangeFrom = iterableRange.from as? NumericLiteralValue
+        val rangeTo = iterableRange.to as? NumericLiteralValue
+        if(rangeFrom==null || rangeTo==null) return forLoop2
 
-        val loopvar = resultStmt.loopVar?.targetVarDecl(program.namespace)
+        val loopvar = forLoop2.loopVar?.targetVarDecl(program.namespace)
         if(loopvar!=null) {
-            val stepLiteral = iterableRange.step as? LiteralValue
+            val stepLiteral = iterableRange.step as? NumericLiteralValue
             when(loopvar.datatype) {
                 DataType.UBYTE -> {
-                    if(rangeFrom.type!=DataType.UBYTE) {
+                    if(rangeFrom.type!= DataType.UBYTE) {
                         // attempt to translate the iterable into ubyte values
-                        resultStmt.iterable = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
+                        forLoop2.iterable = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
                     }
                 }
                 DataType.BYTE -> {
-                    if(rangeFrom.type!=DataType.BYTE) {
+                    if(rangeFrom.type!= DataType.BYTE) {
                         // attempt to translate the iterable into byte values
-                        resultStmt.iterable = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
+                        forLoop2.iterable = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
                     }
                 }
                 DataType.UWORD -> {
-                    if(rangeFrom.type!=DataType.UWORD) {
+                    if(rangeFrom.type!= DataType.UWORD) {
                         // attempt to translate the iterable into uword values
-                        resultStmt.iterable = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
+                        forLoop2.iterable = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
                     }
                 }
                 DataType.WORD -> {
-                    if(rangeFrom.type!=DataType.WORD) {
+                    if(rangeFrom.type!= DataType.WORD) {
                         // attempt to translate the iterable into word values
-                        resultStmt.iterable = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
+                        forLoop2.iterable = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
                     }
                 }
                 else -> throw FatalAstException("invalid loopvar datatype $loopvar")
             }
         }
-        return resultStmt
+        return forLoop2
     }
 
-    override fun process(literalValue: LiteralValue): LiteralValue {
-        val litval = super.process(literalValue)
-        if(litval.isString) {
-            // intern the string; move it into the heap
-            if(litval.strvalue!!.length !in 1..255)
-                addError(ExpressionError("string literal length must be between 1 and 255", litval.position))
-            else {
-                litval.addToHeap(program.heap)  // TODO: we don't know the actual string type yet, STR != STR_S etc...
+    override fun visit(arrayLiteral: ArrayLiteralValue): Expression {
+        val array = super.visit(arrayLiteral)
+        if(array is ArrayLiteralValue) {
+            val vardecl = array.parent as? VarDecl
+            return if (vardecl!=null) {
+                fixupArrayEltDatatypesFromVardecl(array, vardecl)
+            } else {
+                // it's not an array associated with a vardecl, attempt to guess the data type from the array values
+                fixupArrayEltDatatypes(array, program)
             }
-        } else if(litval.arrayvalue!=null) {
-            // first, adjust the array datatype
-            val litval2 = adjustArrayValDatatype(litval)
-            litval2.addToHeap(program.heap)
-            return litval2
         }
-        return litval
+        return array
     }
 
-    private fun adjustArrayValDatatype(litval: LiteralValue): LiteralValue {
-        val array = litval.arrayvalue!!
-        val typesInArray = array.mapNotNull { it.inferType(program) }.toSet()
-        val arrayDt =
-                when {
-                    array.any { it is AddressOf} -> DataType.ARRAY_UW
-                    DataType.FLOAT in typesInArray -> DataType.ARRAY_F
-                    DataType.WORD in typesInArray -> DataType.ARRAY_W
-                    else -> {
-                        val allElementsAreConstantOrAddressOf = array.fold(true) { c, expr-> c and (expr is LiteralValue || expr is AddressOf)}
-                        if(!allElementsAreConstantOrAddressOf) {
-                            addError(ExpressionError("array literal can only consist of constant primitive numerical values or memory pointers", litval.position))
-                            return litval
-                        } else {
-                            val integerArray = array.map { it.constValue(program)!!.asIntegerValue!! }
-                            val maxValue = integerArray.max()!!
-                            val minValue = integerArray.min()!!
-                            if (minValue >= 0) {
-                                // unsigned
-                                if (maxValue <= 255)
-                                    DataType.ARRAY_UB
-                                else
-                                    DataType.ARRAY_UW
-                            } else {
-                                // signed
-                                if (maxValue <= 127)
-                                    DataType.ARRAY_B
-                                else
-                                    DataType.ARRAY_W
-                            }
-                        }
-                    }
-                }
-
-        if(arrayDt!=litval.type) {
-            return LiteralValue(arrayDt, arrayvalue = litval.arrayvalue, position = litval.position)
-        }
-        return litval
-    }
-
-    override fun process(assignment: Assignment): IStatement {
-        super.process(assignment)
-        val lv = assignment.value as? LiteralValue
+    override fun visit(assignment: Assignment): Statement {
+        super.visit(assignment)
+        val lv = assignment.value as? NumericLiteralValue
         if(lv!=null) {
             // see if we can promote/convert a literal value to the required datatype
-            when(assignment.singleTarget?.inferType(program, assignment)) {
+            val idt = assignment.target.inferType(program, assignment)
+            if(!idt.isKnown)
+                return assignment
+            when(idt.typeOrElse(DataType.STRUCT)) {
                 DataType.UWORD -> {
                     // we can convert to UWORD: any UBYTE, BYTE/WORD that are >=0, FLOAT that's an integer 0..65535,
-                    if(lv.type==DataType.UBYTE)
-                        assignment.value = LiteralValue(DataType.UWORD, wordvalue = lv.asIntegerValue, position=lv.position)
-                    else if(lv.type==DataType.BYTE && lv.bytevalue!!>=0)
-                        assignment.value = LiteralValue(DataType.UWORD, wordvalue = lv.asIntegerValue, position=lv.position)
-                    else if(lv.type==DataType.WORD && lv.wordvalue!!>=0)
-                        assignment.value = LiteralValue(DataType.UWORD, wordvalue = lv.asIntegerValue, position=lv.position)
-                    else if(lv.type==DataType.FLOAT) {
-                        val d = lv.floatvalue!!
+                    if(lv.type== DataType.UBYTE)
+                        assignment.value = NumericLiteralValue(DataType.UWORD, lv.number.toInt(), lv.position)
+                    else if(lv.type== DataType.BYTE && lv.number.toInt()>=0)
+                        assignment.value = NumericLiteralValue(DataType.UWORD, lv.number.toInt(), lv.position)
+                    else if(lv.type== DataType.WORD && lv.number.toInt()>=0)
+                        assignment.value = NumericLiteralValue(DataType.UWORD, lv.number.toInt(), lv.position)
+                    else if(lv.type== DataType.FLOAT) {
+                        val d = lv.number.toDouble()
                         if(floor(d)==d && d>=0 && d<=65535)
-                            assignment.value = LiteralValue(DataType.UWORD, wordvalue=floor(d).toInt(), position=lv.position)
+                            assignment.value = NumericLiteralValue(DataType.UWORD, floor(d).toInt(), lv.position)
                     }
                 }
                 DataType.UBYTE -> {
                     // we can convert to UBYTE: UWORD <=255, BYTE >=0, FLOAT that's an integer 0..255,
-                    if(lv.type==DataType.UWORD && lv.wordvalue!! <= 255)
-                        assignment.value = LiteralValue(DataType.UBYTE, lv.wordvalue.toShort(), position=lv.position)
-                    else if(lv.type==DataType.BYTE && lv.bytevalue!! >=0)
-                        assignment.value = LiteralValue(DataType.UBYTE, lv.bytevalue.toShort(), position=lv.position)
-                    else if(lv.type==DataType.FLOAT) {
-                        val d = lv.floatvalue!!
+                    if(lv.type== DataType.UWORD && lv.number.toInt() <= 255)
+                        assignment.value = NumericLiteralValue(DataType.UBYTE, lv.number.toShort(), lv.position)
+                    else if(lv.type== DataType.BYTE && lv.number.toInt() >=0)
+                        assignment.value = NumericLiteralValue(DataType.UBYTE, lv.number.toShort(), lv.position)
+                    else if(lv.type== DataType.FLOAT) {
+                        val d = lv.number.toDouble()
                         if(floor(d)==d && d >=0 && d<=255)
-                            assignment.value = LiteralValue(DataType.UBYTE, floor(d).toShort(), position=lv.position)
+                            assignment.value = NumericLiteralValue(DataType.UBYTE, floor(d).toShort(), lv.position)
                     }
                 }
                 DataType.BYTE -> {
                     // we can convert to BYTE: UWORD/UBYTE <= 127, FLOAT that's an integer 0..127
-                    if(lv.type==DataType.UWORD && lv.wordvalue!! <= 127)
-                        assignment.value = LiteralValue(DataType.BYTE, lv.wordvalue.toShort(), position=lv.position)
-                    else if(lv.type==DataType.UBYTE && lv.bytevalue!! <= 127)
-                        assignment.value = LiteralValue(DataType.BYTE, lv.bytevalue, position=lv.position)
-                    else if(lv.type==DataType.FLOAT) {
-                        val d = lv.floatvalue!!
+                    if(lv.type== DataType.UWORD && lv.number.toInt() <= 127)
+                        assignment.value = NumericLiteralValue(DataType.BYTE, lv.number.toShort(), lv.position)
+                    else if(lv.type== DataType.UBYTE && lv.number.toInt() <= 127)
+                        assignment.value = NumericLiteralValue(DataType.BYTE, lv.number.toShort(), lv.position)
+                    else if(lv.type== DataType.FLOAT) {
+                        val d = lv.number.toDouble()
                         if(floor(d)==d && d>=0 && d<=127)
-                            assignment.value = LiteralValue(DataType.BYTE, floor(d).toShort(), position=lv.position)
+                            assignment.value = NumericLiteralValue(DataType.BYTE, floor(d).toShort(), lv.position)
                     }
                 }
                 DataType.WORD -> {
                     // we can convert to WORD: any UBYTE/BYTE, UWORD <= 32767, FLOAT that's an integer -32768..32767,
-                    if(lv.type==DataType.UBYTE || lv.type==DataType.BYTE)
-                        assignment.value = LiteralValue(DataType.WORD, wordvalue=lv.bytevalue!!.toInt(), position=lv.position)
-                    else if(lv.type==DataType.UWORD && lv.wordvalue!! <= 32767)
-                        assignment.value = LiteralValue(DataType.WORD, wordvalue=lv.wordvalue, position=lv.position)
-                    else if(lv.type==DataType.FLOAT) {
-                        val d = lv.floatvalue!!
+                    if(lv.type== DataType.UBYTE || lv.type== DataType.BYTE)
+                        assignment.value = NumericLiteralValue(DataType.WORD, lv.number.toInt(), lv.position)
+                    else if(lv.type== DataType.UWORD && lv.number.toInt() <= 32767)
+                        assignment.value = NumericLiteralValue(DataType.WORD, lv.number.toInt(), lv.position)
+                    else if(lv.type== DataType.FLOAT) {
+                        val d = lv.number.toDouble()
                         if(floor(d)==d && d>=-32768 && d<=32767)
-                            assignment.value = LiteralValue(DataType.BYTE, floor(d).toShort(), position=lv.position)
+                            assignment.value = NumericLiteralValue(DataType.BYTE, floor(d).toShort(), lv.position)
                     }
                 }
                 DataType.FLOAT -> {
-                    if(lv.isNumeric)
-                        assignment.value = LiteralValue(DataType.FLOAT, floatvalue= lv.asNumericValue?.toDouble(), position=lv.position)
+                    assignment.value = NumericLiteralValue(DataType.FLOAT, lv.number.toDouble(), lv.position)
                 }
                 else -> {}
             }

compiler/src/prog8/optimizer/Extensions.kt

@@ -1,20 +1,21 @@
-package prog8.optimizing
+package prog8.optimizer
 
-import prog8.ast.*
+import prog8.ast.Program
+import prog8.ast.base.AstException
 import prog8.parser.ParsingFailedError
 
 
 internal fun Program.constantFold() {
     val optimizer = ConstantFolding(this)
     try {
-        optimizer.process(this)
+        optimizer.visit(this)
     } catch (ax: AstException) {
         optimizer.addError(ax)
     }
 
     while(optimizer.errors.isEmpty() && optimizer.optimizationsDone>0) {
         optimizer.optimizationsDone = 0
-        optimizer.process(this)
+        optimizer.visit(this)
     }
 
     if(optimizer.errors.isNotEmpty()) {
@@ -26,17 +27,9 @@ internal fun Program.constantFold() {
 }
 
 
-internal fun Program.optimizeStatements(optimizeInlining: Boolean): Int {
-    val optimizer = StatementOptimizer(this, optimizeInlining)
-    optimizer.process(this)
-    for(scope in optimizer.scopesToFlatten.reversed()) {
-        val namescope = scope.parent as INameScope
-        val idx = namescope.statements.indexOf(scope as IStatement)
-        if(idx>=0) {
-            namescope.statements[idx] = NopStatement(scope.position)
-            namescope.statements.addAll(idx, scope.statements)
-        }
-    }
+internal fun Program.optimizeStatements(): Int {
+    val optimizer = StatementOptimizer(this)
+    optimizer.visit(this)
     modules.forEach { it.linkParents(this.namespace) }   // re-link in final configuration
 
     return optimizer.optimizationsDone
@@ -44,6 +37,6 @@ internal fun Program.optimizeStatements(optimizeInlining: Boolean): Int {
 
 internal fun Program.simplifyExpressions() : Int {
     val optimizer = SimplifyExpressions(this)
-    optimizer.process(this)
+    optimizer.visit(this)
     return optimizer.optimizationsDone
 }

compiler/src/prog8/optimizer/SimplifyExpressions.kt

@@ -1,67 +1,90 @@
-package prog8.optimizing
+package prog8.optimizer
 
-import prog8.ast.*
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.processing.IAstModifyingVisitor
+import prog8.ast.statements.Assignment
+import prog8.ast.statements.Statement
 import kotlin.math.abs
 import kotlin.math.log2
+import kotlin.math.pow
 
 /*
-    todo advanced expression optimization: common (sub) expression elimination (turn common expressions into single subroutine call + introduce variable to hold it)
+    todo add more expression optimizations
 
     Also see  https://egorbo.com/peephole-optimizations.html
 
  */
 
-internal class SimplifyExpressions(private val program: Program) : IAstProcessor {
+internal class SimplifyExpressions(private val program: Program) : IAstModifyingVisitor {
     var optimizationsDone: Int = 0
 
-    override fun process(assignment: Assignment): IStatement {
+    override fun visit(assignment: Assignment): Statement {
         if (assignment.aug_op != null)
             throw AstException("augmented assignments should have been converted to normal assignments before this optimizer")
-        return super.process(assignment)
+        return super.visit(assignment)
     }
 
-    override fun process(memread: DirectMemoryRead): IExpression {
+    override fun visit(memread: DirectMemoryRead): Expression {
         // @( &thing )  -->  thing
         val addrOf = memread.addressExpression as? AddressOf
         if(addrOf!=null)
-            return super.process(addrOf.identifier)
-        return super.process(memread)
+            return super.visit(addrOf.identifier)
+        return super.visit(memread)
     }
 
-    override fun process(memwrite: DirectMemoryWrite): IExpression {
-        // @( &thing )  -->  thing
-        val addrOf = memwrite.addressExpression as? AddressOf
-        if(addrOf!=null)
-            return super.process(addrOf.identifier)
-        return super.process(memwrite)
-    }
-
-    override fun process(typecast: TypecastExpression): IExpression {
-        // remove redundant typecasts
+    override fun visit(typecast: TypecastExpression): Expression {
         var tc = typecast
+
+        // try to statically convert a literal value into one of the desired type
+        val literal = tc.expression as? NumericLiteralValue
+        if(literal!=null) {
+            val newLiteral = literal.cast(tc.type)
+            if(newLiteral!==literal) {
+                optimizationsDone++
+                return newLiteral
+            }
+        }
+
+        // remove redundant typecasts
         while(true) {
             val expr = tc.expression
             if(expr !is TypecastExpression || expr.type!=tc.type) {
                 val assignment = typecast.parent as? Assignment
                 if(assignment!=null) {
-                    val targetDt = assignment.singleTarget?.inferType(program, assignment)
+                    val targetDt = assignment.target.inferType(program, assignment)
                     if(tc.expression.inferType(program)==targetDt) {
                         optimizationsDone++
                         return tc.expression
                     }
                 }
-                return super.process(tc)
+
+                val subTc = tc.expression as? TypecastExpression
+                if(subTc!=null) {
+                    // if the previous typecast was casting to a 'bigger' type, just ignore that one
+                    // if the previous typecast was casting to a similar type, ignore that one
+                    if(subTc.type largerThan tc.type || subTc.type equalsSize tc.type) {
+                        subTc.type = tc.type
+                        subTc.parent = tc.parent
+                        optimizationsDone++
+                        return subTc
+                    }
+                }
+
+                return super.visit(tc)
             }
+
             optimizationsDone++
             tc = expr
         }
     }
 
-    override fun process(expr: PrefixExpression): IExpression {
+    override fun visit(expr: PrefixExpression): Expression {
         if (expr.operator == "+") {
             // +X --> X
             optimizationsDone++
-            return expr.expression.process(this)
+            return expr.expression.accept(this)
         } else if (expr.operator == "not") {
             (expr.expression as? BinaryExpression)?.let {
                 // NOT (...)  ->   invert  ...
@@ -101,19 +124,24 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
                 }
             }
         }
-        return super.process(expr)
+        return super.visit(expr)
     }
 
-    override fun process(expr: BinaryExpression): IExpression {
-        super.process(expr)
+    override fun visit(expr: BinaryExpression): Expression {
+        super.visit(expr)
         val leftVal = expr.left.constValue(program)
         val rightVal = expr.right.constValue(program)
-        val constTrue = LiteralValue.fromBoolean(true, expr.position)
-        val constFalse = LiteralValue.fromBoolean(false, expr.position)
+        val constTrue = NumericLiteralValue.fromBoolean(true, expr.position)
+        val constFalse = NumericLiteralValue.fromBoolean(false, expr.position)
 
-        val leftDt = expr.left.inferType(program)
-        val rightDt = expr.right.inferType(program)
-        if (leftDt != null && rightDt != null && leftDt != rightDt) {
+        val leftIDt = expr.left.inferType(program)
+        val rightIDt = expr.right.inferType(program)
+        if(!leftIDt.isKnown || !rightIDt.isKnown)
+            throw FatalAstException("can't determine datatype of both expression operands $expr")
+
+        val leftDt = leftIDt.typeOrElse(DataType.STRUCT)
+        val rightDt = rightIDt.typeOrElse(DataType.STRUCT)
+        if (leftDt != rightDt) {
             // try to convert a datatype into the other (where ddd
             if (adjustDatatypes(expr, leftVal, leftDt, rightVal, rightDt)) {
                 optimizationsDone++
@@ -150,10 +178,10 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
 
         // X + (-value)  -->  X - value
         if (expr.operator == "+" && rightVal != null) {
-            val rv = rightVal.asNumericValue?.toDouble()
-            if (rv != null && rv < 0.0) {
+            val rv = rightVal.number.toDouble()
+            if (rv < 0.0) {
                 expr.operator = "-"
-                expr.right = LiteralValue.fromNumber(-rv, rightVal.type, rightVal.position)
+                expr.right = NumericLiteralValue(rightVal.type, -rv, rightVal.position)
                 optimizationsDone++
                 return expr
             }
@@ -161,10 +189,10 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
 
         // (-value) + X  -->  X - value
         if (expr.operator == "+" && leftVal != null) {
-            val lv = leftVal.asNumericValue?.toDouble()
-            if (lv != null && lv < 0.0) {
+            val lv = leftVal.number.toDouble()
+            if (lv < 0.0) {
                 expr.operator = "-"
-                expr.right = LiteralValue.fromNumber(-lv, leftVal.type, leftVal.position)
+                expr.right = NumericLiteralValue(leftVal.type, -lv, leftVal.position)
                 optimizationsDone++
                 return expr
             }
@@ -180,10 +208,10 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
 
         // X - (-value)  -->  X + value
         if (expr.operator == "-" && rightVal != null) {
-            val rv = rightVal.asNumericValue?.toDouble()
-            if (rv != null && rv < 0.0) {
+            val rv = rightVal.number.toDouble()
+            if (rv < 0.0) {
                 expr.operator = "+"
-                expr.right = LiteralValue.fromNumber(-rv, rightVal.type, rightVal.position)
+                expr.right = NumericLiteralValue(rightVal.type, -rv, rightVal.position)
                 optimizationsDone++
                 return expr
             }
@@ -201,7 +229,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
                     val x = expr.right
                     val y = determineY(x, leftBinExpr)
                     if(y!=null) {
-                        val yPlus1 = BinaryExpression(y, "+", LiteralValue.fromNumber(1, leftDt!!, y.position), y.position)
+                        val yPlus1 = BinaryExpression(y, "+", NumericLiteralValue(leftDt, 1, y.position), y.position)
                         return BinaryExpression(x, "*", yPlus1, x.position)
                     }
                 } else {
@@ -210,7 +238,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
                     val x = expr.right
                     val y = determineY(x, leftBinExpr)
                     if(y!=null) {
-                        val yMinus1 = BinaryExpression(y, "-", LiteralValue.fromNumber(1, leftDt!!, y.position), y.position)
+                        val yMinus1 = BinaryExpression(y, "-", NumericLiteralValue(leftDt, 1, y.position), y.position)
                         return BinaryExpression(x, "*", yMinus1, x.position)
                     }
                 }
@@ -222,7 +250,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
                     val x = expr.left
                     val y = determineY(x, rightBinExpr)
                     if(y!=null) {
-                        val yPlus1 = BinaryExpression(y, "+", LiteralValue.optimalInteger(1, y.position), y.position)
+                        val yPlus1 = BinaryExpression(y, "+", NumericLiteralValue.optimalInteger(1, y.position), y.position)
                         return BinaryExpression(x, "*", yPlus1, x.position)
                     }
                 } else {
@@ -231,7 +259,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
                     val x = expr.left
                     val y = determineY(x, rightBinExpr)
                     if(y!=null) {
-                        val oneMinusY = BinaryExpression(LiteralValue.optimalInteger(1, y.position), "-", y, y.position)
+                        val oneMinusY = BinaryExpression(NumericLiteralValue.optimalInteger(1, y.position), "-", y, y.position)
                         return BinaryExpression(x, "*", oneMinusY, x.position)
                     }
                 }
@@ -313,11 +341,13 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
             "-" -> return optimizeSub(expr, leftVal, rightVal)
             "**" -> return optimizePower(expr, leftVal, rightVal)
             "%" -> return optimizeRemainder(expr, leftVal, rightVal)
+            ">>" -> return optimizeShiftRight(expr, rightVal)
+            "<<" -> return optimizeShiftLeft(expr, rightVal)
         }
         return expr
     }
 
-    private fun determineY(x: IExpression, subBinExpr: BinaryExpression): IExpression? {
+    private fun determineY(x: Expression, subBinExpr: BinaryExpression): Expression? {
         return when {
             subBinExpr.left isSameAs x -> subBinExpr.right
             subBinExpr.right isSameAs x -> subBinExpr.left
@@ -326,58 +356,58 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
     }
 
     private fun adjustDatatypes(expr: BinaryExpression,
-                                leftConstVal: LiteralValue?, leftDt: DataType,
-                                rightConstVal: LiteralValue?, rightDt: DataType): Boolean {
+                                leftConstVal: NumericLiteralValue?, leftDt: DataType,
+                                rightConstVal: NumericLiteralValue?, rightDt: DataType): Boolean {
 
-        fun adjust(value: LiteralValue, targetDt: DataType): Pair<Boolean, LiteralValue>{
+        fun adjust(value: NumericLiteralValue, targetDt: DataType): Pair<Boolean, NumericLiteralValue>{
             if(value.type==targetDt)
                 return Pair(false, value)
             when(value.type) {
                 DataType.UBYTE -> {
                     if (targetDt == DataType.BYTE) {
-                        if(value.bytevalue!! < 127)
-                            return Pair(true, LiteralValue(targetDt, value.bytevalue, position=value.position))
+                        if(value.number.toInt() < 127)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
                     }
                     else if (targetDt == DataType.UWORD || targetDt == DataType.WORD)
-                        return Pair(true, LiteralValue(targetDt, wordvalue = value.bytevalue!!.toInt(), position=value.position))
+                        return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
                 }
                 DataType.BYTE -> {
                     if (targetDt == DataType.UBYTE) {
-                        if(value.bytevalue!! >= 0)
-                            return Pair(true, LiteralValue(targetDt, value.bytevalue, position=value.position))
+                        if(value.number.toInt() >= 0)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
                     }
                     else if (targetDt == DataType.UWORD) {
-                        if(value.bytevalue!! >= 0)
-                            return Pair(true, LiteralValue(targetDt, wordvalue=value.bytevalue.toInt(), position=value.position))
+                        if(value.number.toInt() >= 0)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
                     }
-                    else if (targetDt == DataType.WORD) return Pair(true, LiteralValue(targetDt, wordvalue=value.bytevalue!!.toInt(), position=value.position))
+                    else if (targetDt == DataType.WORD) return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
                 }
                 DataType.UWORD -> {
                     if (targetDt == DataType.UBYTE) {
-                        if(value.wordvalue!! <= 255)
-                            return Pair(true, LiteralValue(targetDt, value.wordvalue.toShort(), position=value.position))
+                        if(value.number.toInt() <= 255)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
                     }
                     else if (targetDt == DataType.BYTE) {
-                        if(value.wordvalue!! <= 127)
-                            return Pair(true, LiteralValue(targetDt, value.wordvalue.toShort(), position=value.position))
+                        if(value.number.toInt() <= 127)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
                     }
                     else if (targetDt == DataType.WORD) {
-                        if(value.wordvalue!! <= 32767)
-                            return Pair(true, LiteralValue(targetDt, wordvalue=value.wordvalue, position=value.position))
+                        if(value.number.toInt() <= 32767)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
                     }
                 }
                 DataType.WORD -> {
                     if (targetDt == DataType.UBYTE) {
-                        if(value.wordvalue!! in 0..255)
-                            return Pair(true, LiteralValue(targetDt, value.wordvalue.toShort(), position=value.position))
+                        if(value.number.toInt() in 0..255)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
                     }
                     else if (targetDt == DataType.BYTE) {
-                        if(value.wordvalue!! in -128..127)
-                            return Pair(true, LiteralValue(targetDt, value.wordvalue.toShort(), position=value.position))
+                        if(value.number.toInt() in -128..127)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
                     }
                     else if (targetDt == DataType.UWORD) {
-                        if(value.wordvalue!! >= 0)
-                            return Pair(true, LiteralValue(targetDt, value.wordvalue.toShort(), position=value.position))
+                        if(value.number.toInt() >= 0)
+                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
                     }
                 }
                 else -> {}
@@ -386,7 +416,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
         }
 
         if(leftConstVal==null && rightConstVal!=null) {
-            if(leftDt biggerThan rightDt) {
+            if(leftDt largerThan rightDt) {
                 val (adjusted, newValue) = adjust(rightConstVal, leftDt)
                 if (adjusted) {
                     expr.right = newValue
@@ -396,7 +426,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
             }
             return false
         } else if(leftConstVal!=null && rightConstVal==null) {
-            if(rightDt biggerThan leftDt) {
+            if(rightDt largerThan leftDt) {
                 val (adjusted, newValue) = adjust(leftConstVal, rightDt)
                 if (adjusted) {
                     expr.left = newValue
@@ -410,9 +440,9 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
         }
     }
 
-    private data class ReorderedAssociativeBinaryExpr(val expr: BinaryExpression, val leftVal: LiteralValue?, val rightVal: LiteralValue?)
+    private data class ReorderedAssociativeBinaryExpr(val expr: BinaryExpression, val leftVal: NumericLiteralValue?, val rightVal: NumericLiteralValue?)
 
-    private fun reorderAssociative(expr: BinaryExpression, leftVal: LiteralValue?): ReorderedAssociativeBinaryExpr {
+    private fun reorderAssociative(expr: BinaryExpression, leftVal: NumericLiteralValue?): ReorderedAssociativeBinaryExpr {
         if(expr.operator in associativeOperators && leftVal!=null) {
             // swap left and right so that right is always the constant
             val tmp = expr.left
@@ -424,15 +454,15 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
         return ReorderedAssociativeBinaryExpr(expr, leftVal, expr.right.constValue(program))
     }
 
-    private fun optimizeAdd(pexpr: BinaryExpression, pleftVal: LiteralValue?, prightVal: LiteralValue?): IExpression {
+    private fun optimizeAdd(pexpr: BinaryExpression, pleftVal: NumericLiteralValue?, prightVal: NumericLiteralValue?): Expression {
         if(pleftVal==null && prightVal==null)
             return pexpr
 
         val (expr, _, rightVal) = reorderAssociative(pexpr, pleftVal)
         if(rightVal!=null) {
             // right value is a constant, see if we can optimize
-            val rightConst: LiteralValue = rightVal
-            when(rightConst.asNumericValue?.toDouble()) {
+            val rightConst: NumericLiteralValue = rightVal
+            when(rightConst.number.toDouble()) {
                 0.0 -> {
                     // left
                     optimizationsDone++
@@ -445,14 +475,14 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
         return expr
     }
 
-    private fun optimizeSub(expr: BinaryExpression, leftVal: LiteralValue?, rightVal: LiteralValue?): IExpression {
+    private fun optimizeSub(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression {
         if(leftVal==null && rightVal==null)
             return expr
 
         if(rightVal!=null) {
             // right value is a constant, see if we can optimize
-            val rightConst: LiteralValue = rightVal
-            when(rightConst.asNumericValue?.toDouble()) {
+            val rightConst: NumericLiteralValue = rightVal
+            when(rightConst.number.toDouble()) {
                 0.0 -> {
                     // left
                     optimizationsDone++
@@ -462,7 +492,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
         }
         if(leftVal!=null) {
             // left value is a constant, see if we can optimize
-            when(leftVal.asNumericValue?.toDouble()) {
+            when(leftVal.number.toDouble()) {
                 0.0 -> {
                     // -right
                     optimizationsDone++
@@ -474,38 +504,38 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
         return expr
     }
 
-    private fun optimizePower(expr: BinaryExpression, leftVal: LiteralValue?, rightVal: LiteralValue?): IExpression {
+    private fun optimizePower(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression {
         if(leftVal==null && rightVal==null)
             return expr
 
         if(rightVal!=null) {
             // right value is a constant, see if we can optimize
-            val rightConst: LiteralValue = rightVal
-            when(rightConst.asNumericValue?.toDouble()) {
+            val rightConst: NumericLiteralValue = rightVal
+            when(rightConst.number.toDouble()) {
                 -3.0 -> {
                     // -1/(left*left*left)
                     optimizationsDone++
-                    return BinaryExpression(LiteralValue(DataType.FLOAT, floatvalue = -1.0, position = expr.position), "/",
+                    return BinaryExpression(NumericLiteralValue(DataType.FLOAT, -1.0, expr.position), "/",
                             BinaryExpression(expr.left, "*", BinaryExpression(expr.left, "*", expr.left, expr.position), expr.position),
                             expr.position)
                 }
                 -2.0 -> {
                     // -1/(left*left)
                     optimizationsDone++
-                    return BinaryExpression(LiteralValue(DataType.FLOAT, floatvalue = -1.0, position = expr.position), "/",
+                    return BinaryExpression(NumericLiteralValue(DataType.FLOAT, -1.0, expr.position), "/",
                             BinaryExpression(expr.left, "*", expr.left, expr.position),
                             expr.position)
                 }
                 -1.0 -> {
                     // -1/left
                     optimizationsDone++
-                    return BinaryExpression(LiteralValue(DataType.FLOAT, floatvalue = -1.0, position = expr.position), "/",
+                    return BinaryExpression(NumericLiteralValue(DataType.FLOAT, -1.0, expr.position), "/",
                             expr.left, expr.position)
                 }
                 0.0 -> {
                     // 1
                     optimizationsDone++
-                    return LiteralValue.fromNumber(1, rightConst.type, expr.position)
+                    return NumericLiteralValue(rightConst.type, 1, expr.position)
                 }
                 0.5 -> {
                     // sqrt(left)
@@ -531,21 +561,21 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
         }
         if(leftVal!=null) {
             // left value is a constant, see if we can optimize
-            when(leftVal.asNumericValue?.toDouble()) {
+            when(leftVal.number.toDouble()) {
                 -1.0 -> {
                     // -1
                     optimizationsDone++
-                    return LiteralValue(DataType.FLOAT, floatvalue = -1.0, position = expr.position)
+                    return NumericLiteralValue(DataType.FLOAT, -1.0, expr.position)
                 }
                 0.0 -> {
                     // 0
                     optimizationsDone++
-                    return LiteralValue.fromNumber(0, leftVal.type, expr.position)
+                    return NumericLiteralValue(leftVal.type, 0, expr.position)
                 }
                 1.0 -> {
                     //1
                     optimizationsDone++
-                    return LiteralValue.fromNumber(1, leftVal.type, expr.position)
+                    return NumericLiteralValue(leftVal.type, 1, expr.position)
                 }
 
             }
@@ -554,22 +584,22 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
         return expr
     }
 
-    private fun optimizeRemainder(expr: BinaryExpression, leftVal: LiteralValue?, rightVal: LiteralValue?): IExpression {
+    private fun optimizeRemainder(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression {
         if(leftVal==null && rightVal==null)
             return expr
 
         // simplify assignments  A = B <operator> C
 
-        val cv = rightVal?.asIntegerValue?.toDouble()
+        val cv = rightVal?.number?.toInt()?.toDouble()
         when(expr.operator) {
             "%" -> {
                 if (cv == 1.0) {
                     optimizationsDone++
-                    return LiteralValue.fromNumber(0, expr.inferType(program)!!, expr.position)
+                    return NumericLiteralValue(expr.inferType(program).typeOrElse(DataType.STRUCT), 0, expr.position)
                 } else if (cv == 2.0) {
                     optimizationsDone++
                     expr.operator = "&"
-                    expr.right = LiteralValue.optimalInteger(1, expr.position)
+                    expr.right = NumericLiteralValue.optimalInteger(1, expr.position)
                     return expr
                 }
             }
@@ -578,17 +608,22 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
 
     }
 
-    private fun optimizeDivision(expr: BinaryExpression, leftVal: LiteralValue?, rightVal: LiteralValue?): IExpression {
+    private val powersOfTwo = (1 .. 16).map { (2.0).pow(it) }.toSet()
+    private val negativePowersOfTwo = powersOfTwo.map { -it }.toSet()
+
+    private fun optimizeDivision(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression {
         if(leftVal==null && rightVal==null)
             return expr
 
         // cannot shuffle assiciativity with division!
-
         if(rightVal!=null) {
             // right value is a constant, see if we can optimize
-            val rightConst: LiteralValue = rightVal
-            val cv = rightConst.asNumericValue?.toDouble()
-            val leftDt = expr.left.inferType(program)
+            val rightConst: NumericLiteralValue = rightVal
+            val cv = rightConst.number.toDouble()
+            val leftIDt = expr.left.inferType(program)
+            if(!leftIDt.isKnown)
+                return expr
+            val leftDt = leftIDt.typeOrElse(DataType.STRUCT)
             when(cv) {
                 -1.0 -> {
                     //  '/' -> -left
@@ -604,45 +639,45 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
                         return expr.left
                     }
                 }
-                2.0, 4.0, 8.0, 16.0, 32.0, 64.0, 128.0, 256.0, 512.0, 1024.0, 2048.0, 4096.0, 8192.0, 16384.0, 32768.0, 65536.0 -> {
+                in powersOfTwo -> {
                     if(leftDt in IntegerDatatypes) {
                         // divided by a power of two => shift right
                         optimizationsDone++
                         val numshifts = log2(cv).toInt()
-                        return BinaryExpression(expr.left, ">>", LiteralValue.optimalInteger(numshifts, expr.position), expr.position)
+                        return BinaryExpression(expr.left, ">>", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
                     }
                 }
-                -2.0, -4.0, -8.0, -16.0, -32.0, -64.0, -128.0, -256.0, -512.0, -1024.0, -2048.0, -4096.0, -8192.0, -16384.0, -32768.0, -65536.0 -> {
+                in negativePowersOfTwo -> {
                     if(leftDt in IntegerDatatypes) {
                         // divided by a negative power of two => negate, then shift right
                         optimizationsDone++
                         val numshifts = log2(-cv).toInt()
-                        return BinaryExpression(PrefixExpression("-", expr.left, expr.position), ">>", LiteralValue.optimalInteger(numshifts, expr.position), expr.position)
+                        return BinaryExpression(PrefixExpression("-", expr.left, expr.position), ">>", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
                     }
                 }
             }
 
             if (leftDt == DataType.UBYTE) {
-                if(abs(rightConst.asNumericValue!!.toDouble()) >= 256.0) {
+                if(abs(rightConst.number.toDouble()) >= 256.0) {
                     optimizationsDone++
-                    return LiteralValue(DataType.UBYTE, 0, position = expr.position)
+                    return NumericLiteralValue(DataType.UBYTE, 0, expr.position)
                 }
             }
             else if (leftDt == DataType.UWORD) {
-                if(abs(rightConst.asNumericValue!!.toDouble()) >= 65536.0) {
+                if(abs(rightConst.number.toDouble()) >= 65536.0) {
                     optimizationsDone++
-                    return LiteralValue(DataType.UBYTE, 0, position = expr.position)
+                    return NumericLiteralValue(DataType.UBYTE, 0, expr.position)
                 }
             }
         }
 
         if(leftVal!=null) {
             // left value is a constant, see if we can optimize
-            when(leftVal.asNumericValue?.toDouble()) {
+            when(leftVal.number.toDouble()) {
                 0.0 -> {
                     // 0
                     optimizationsDone++
-                    return LiteralValue.fromNumber(0, leftVal.type, expr.position)
+                    return NumericLiteralValue(leftVal.type, 0, expr.position)
                 }
             }
         }
@@ -650,16 +685,16 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
         return expr
     }
 
-    private fun optimizeMultiplication(pexpr: BinaryExpression, pleftVal: LiteralValue?, prightVal: LiteralValue?): IExpression {
+    private fun optimizeMultiplication(pexpr: BinaryExpression, pleftVal: NumericLiteralValue?, prightVal: NumericLiteralValue?): Expression {
         if(pleftVal==null && prightVal==null)
             return pexpr
 
         val (expr, _, rightVal) = reorderAssociative(pexpr, pleftVal)
         if(rightVal!=null) {
             // right value is a constant, see if we can optimize
-            val leftValue: IExpression = expr.left
-            val rightConst: LiteralValue = rightVal
-            when(val cv = rightConst.asNumericValue?.toDouble()) {
+            val leftValue: Expression = expr.left
+            val rightConst: NumericLiteralValue = rightVal
+            when(val cv = rightConst.number.toDouble()) {
                 -1.0 -> {
                     // -left
                     optimizationsDone++
@@ -668,27 +703,27 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
                 0.0 -> {
                     // 0
                     optimizationsDone++
-                    return LiteralValue.fromNumber(0, rightConst.type, expr.position)
+                    return NumericLiteralValue(rightConst.type, 0, expr.position)
                 }
                 1.0 -> {
                     // left
                     optimizationsDone++
                     return expr.left
                 }
-                2.0, 4.0, 8.0, 16.0, 32.0, 64.0, 128.0, 256.0, 512.0, 1024.0, 2048.0, 4096.0, 8192.0, 16384.0, 32768.0, 65536.0 -> {
-                    if(leftValue.inferType(program) in IntegerDatatypes) {
+                in powersOfTwo -> {
+                    if(leftValue.inferType(program).typeOrElse(DataType.STRUCT) in IntegerDatatypes) {
                         // times a power of two => shift left
                         optimizationsDone++
                         val numshifts = log2(cv).toInt()
-                        return BinaryExpression(expr.left, "<<", LiteralValue.optimalInteger(numshifts, expr.position), expr.position)
+                        return BinaryExpression(expr.left, "<<", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
                     }
                 }
-                -2.0, -4.0, -8.0, -16.0, -32.0, -64.0, -128.0, -256.0, -512.0, -1024.0, -2048.0, -4096.0, -8192.0, -16384.0, -32768.0, -65536.0 -> {
-                    if(leftValue.inferType(program) in IntegerDatatypes) {
+                in negativePowersOfTwo -> {
+                    if(leftValue.inferType(program).typeOrElse(DataType.STRUCT) in IntegerDatatypes) {
                         // times a negative power of two => negate, then shift left
                         optimizationsDone++
                         val numshifts = log2(-cv).toInt()
-                        return BinaryExpression(PrefixExpression("-", expr.left, expr.position), "<<", LiteralValue.optimalInteger(numshifts, expr.position), expr.position)
+                        return BinaryExpression(PrefixExpression("-", expr.left, expr.position), "<<", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
                     }
                 }
             }
@@ -697,4 +732,97 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
 
         return expr
     }
+
+    private fun optimizeShiftLeft(expr: BinaryExpression, amountLv: NumericLiteralValue?): Expression {
+        if(amountLv==null)
+            return expr
+
+        val amount=amountLv.number.toInt()
+        if(amount==0) {
+            optimizationsDone++
+            return expr.left
+        }
+        val targetDt = expr.left.inferType(program).typeOrElse(DataType.STRUCT)
+        when(targetDt) {
+            DataType.UBYTE, DataType.BYTE -> {
+                if(amount>=8) {
+                    optimizationsDone++
+                    return NumericLiteralValue.optimalInteger(0, expr.position)
+                }
+            }
+            DataType.UWORD, DataType.WORD -> {
+                if(amount>=16) {
+                    optimizationsDone++
+                    return NumericLiteralValue.optimalInteger(0, expr.position)
+                }
+                else if(amount>=8) {
+                    optimizationsDone++
+                    val lsb=TypecastExpression(expr.left, DataType.UBYTE, true, expr.position)
+                    if(amount==8) {
+                        return FunctionCall(IdentifierReference(listOf("mkword"), expr.position), mutableListOf(NumericLiteralValue.optimalInteger(0, expr.position), lsb), expr.position)
+                    }
+                    val shifted = BinaryExpression(lsb, "<<", NumericLiteralValue.optimalInteger(amount-8, expr.position), expr.position)
+                    return FunctionCall(IdentifierReference(listOf("mkword"), expr.position), mutableListOf(NumericLiteralValue.optimalInteger(0, expr.position), shifted), expr.position)
+                }
+            }
+            else -> {}
+        }
+        return expr
+    }
+
+    private fun optimizeShiftRight(expr: BinaryExpression, amountLv: NumericLiteralValue?): Expression {
+        if(amountLv==null)
+            return expr
+
+        val amount=amountLv.number.toInt()
+        if(amount==0) {
+            optimizationsDone++
+            return expr.left
+        }
+        val targetDt = expr.left.inferType(program).typeOrElse(DataType.STRUCT)
+        when(targetDt) {
+            DataType.UBYTE -> {
+                if(amount>=8) {
+                    optimizationsDone++
+                    return NumericLiteralValue.optimalInteger(0, expr.position)
+                }
+            }
+            DataType.BYTE -> {
+                if(amount>8) {
+                    expr.right = NumericLiteralValue.optimalInteger(8, expr.right.position)
+                    return expr
+                }
+            }
+            DataType.UWORD -> {
+                if(amount>=16) {
+                    optimizationsDone++
+                    return NumericLiteralValue.optimalInteger(0, expr.position)
+                }
+                else if(amount>=8) {
+                    optimizationsDone++
+                    val msb=FunctionCall(IdentifierReference(listOf("msb"), expr.position), mutableListOf(expr.left), expr.position)
+                    if(amount==8)
+                        return msb
+                    return BinaryExpression(msb, ">>", NumericLiteralValue.optimalInteger(amount-8, expr.position), expr.position)
+                }
+            }
+            DataType.WORD -> {
+                if(amount>16) {
+                    expr.right = NumericLiteralValue.optimalInteger(16, expr.right.position)
+                    return expr
+                } else if(amount>=8) {
+                    optimizationsDone++
+                    val msbAsByte = TypecastExpression(
+                            FunctionCall(IdentifierReference(listOf("msb"), expr.position), mutableListOf(expr.left), expr.position),
+                            DataType.BYTE,
+                            true, expr.position)
+                    if(amount==8)
+                        return msbAsByte
+                    return BinaryExpression(msbAsByte, ">>", NumericLiteralValue.optimalInteger(amount-8, expr.position), expr.position)
+                }
+            }
+            else -> {}
+        }
+        return expr
+    }
 }

compiler/src/prog8/optimizer/StatementOptimizer.kt

@@ -0,0 +1,618 @@
+package prog8.optimizer
+
+import prog8.ast.INameScope
+import prog8.ast.Module
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.processing.IAstModifyingVisitor
+import prog8.ast.processing.IAstVisitor
+import prog8.ast.statements.*
+import prog8.compiler.target.CompilationTarget
+import prog8.functions.BuiltinFunctions
+import kotlin.math.floor
+
+
+/*
+    TODO: remove unreachable code?
+    TODO: proper inlining of tiny subroutines (correctly renaming/relocating all variables in them and refs to those as well, or restrict to subs without variables?)
+*/
+
+
+internal class StatementOptimizer(private val program: Program) : IAstModifyingVisitor {
+    var optimizationsDone: Int = 0
+        private set
+
+    private val pureBuiltinFunctions = BuiltinFunctions.filter { it.value.pure }
+    private val callgraph = CallGraph(program)
+    private val vardeclsToRemove = mutableListOf<VarDecl>()
+
+    override fun visit(program: Program) {
+        removeUnusedCode(callgraph)
+        super.visit(program)
+
+        for(decl in vardeclsToRemove) {
+            decl.definingScope().remove(decl)
+        }
+    }
+
+    private fun removeUnusedCode(callgraph: CallGraph) {
+        // remove all subroutines that aren't called, or are empty
+        val removeSubroutines = mutableSetOf<Subroutine>()
+        val entrypoint = program.entrypoint()
+        program.modules.forEach {
+            callgraph.forAllSubroutines(it) { sub ->
+                if (sub !== entrypoint && !sub.keepAlways && (sub.calledBy.isEmpty() || (sub.containsNoCodeNorVars() && !sub.isAsmSubroutine)))
+                    removeSubroutines.add(sub)
+            }
+        }
+
+        if (removeSubroutines.isNotEmpty()) {
+            removeSubroutines.forEach {
+                it.definingScope().remove(it)
+            }
+        }
+
+        val removeBlocks = mutableSetOf<Block>()
+        program.modules.flatMap { it.statements }.filterIsInstance<Block>().forEach { block ->
+            if (block.containsNoCodeNorVars() && "force_output" !in block.options())
+                removeBlocks.add(block)
+        }
+
+        if (removeBlocks.isNotEmpty()) {
+            removeBlocks.forEach { it.definingScope().remove(it) }
+        }
+
+        // remove modules that are not imported, or are empty (unless it's a library modules)
+        val removeModules = mutableSetOf<Module>()
+        program.modules.forEach {
+            if (!it.isLibraryModule && (it.importedBy.isEmpty() || it.containsNoCodeNorVars()))
+                removeModules.add(it)
+        }
+
+        if (removeModules.isNotEmpty()) {
+            program.modules.removeAll(removeModules)
+        }
+    }
+
+    override fun visit(block: Block): Statement {
+        if("force_output" !in block.options()) {
+            if (block.containsNoCodeNorVars()) {
+                optimizationsDone++
+                printWarning("removing empty block '${block.name}'", block.position)
+                return NopStatement.insteadOf(block)
+            }
+
+            if (block !in callgraph.usedSymbols) {
+                optimizationsDone++
+                printWarning("removing unused block '${block.name}'", block.position)
+                return NopStatement.insteadOf(block)  // remove unused block
+            }
+        }
+
+        return super.visit(block)
+    }
+
+    override fun visit(subroutine: Subroutine): Statement {
+        super.visit(subroutine)
+        val forceOutput = "force_output" in subroutine.definingBlock().options()
+        if(subroutine.asmAddress==null && !forceOutput) {
+            if(subroutine.containsNoCodeNorVars()) {
+                printWarning("removing empty subroutine '${subroutine.name}'", subroutine.position)
+                optimizationsDone++
+                return NopStatement.insteadOf(subroutine)
+            }
+        }
+
+        val linesToRemove = deduplicateAssignments(subroutine.statements)
+        if(linesToRemove.isNotEmpty()) {
+            linesToRemove.reversed().forEach{subroutine.statements.removeAt(it)}
+        }
+
+        if(subroutine !in callgraph.usedSymbols && !forceOutput) {
+            printWarning("removing unused subroutine '${subroutine.name}'", subroutine.position)
+            optimizationsDone++
+            return NopStatement.insteadOf(subroutine)
+        }
+
+        return subroutine
+    }
+
+    override fun visit(decl: VarDecl): Statement {
+        val forceOutput = "force_output" in decl.definingBlock().options()
+        if(decl !in callgraph.usedSymbols && !forceOutput) {
+            if(decl.type == VarDeclType.VAR)
+                printWarning("removing unused variable ${decl.type} '${decl.name}'", decl.position)
+            optimizationsDone++
+            return NopStatement.insteadOf(decl)
+        }
+
+        return super.visit(decl)
+    }
+
+    private fun deduplicateAssignments(statements: List<Statement>): MutableList<Int> {
+        // removes 'duplicate' assignments that assign the isSameAs target
+        val linesToRemove = mutableListOf<Int>()
+        var previousAssignmentLine: Int? = null
+        for (i in statements.indices) {
+            val stmt = statements[i] as? Assignment
+            if (stmt != null && stmt.value is NumericLiteralValue) {
+                if (previousAssignmentLine == null) {
+                    previousAssignmentLine = i
+                    continue
+                } else {
+                    val prev = statements[previousAssignmentLine] as Assignment
+                    if (prev.target.isSameAs(stmt.target, program)) {
+                        // get rid of the previous assignment, if the target is not MEMORY
+                        if (prev.target.isNotMemory(program.namespace))
+                            linesToRemove.add(previousAssignmentLine)
+                    }
+                    previousAssignmentLine = i
+                }
+            } else
+                previousAssignmentLine = null
+        }
+        return linesToRemove
+    }
+
+    override fun visit(functionCallStatement: FunctionCallStatement): Statement {
+        if(functionCallStatement.target.nameInSource.size==1 && functionCallStatement.target.nameInSource[0] in BuiltinFunctions) {
+            val functionName = functionCallStatement.target.nameInSource[0]
+            if (functionName in pureBuiltinFunctions) {
+                printWarning("statement has no effect (function return value is discarded)", functionCallStatement.position)
+                optimizationsDone++
+                return NopStatement.insteadOf(functionCallStatement)
+            }
+        }
+
+        if(functionCallStatement.target.nameInSource==listOf("c64scr", "print") ||
+                functionCallStatement.target.nameInSource==listOf("c64scr", "print_p")) {
+            // printing a literal string of just 2 or 1 characters is replaced by directly outputting those characters
+            val arg = functionCallStatement.args.single()
+            val stringVar: IdentifierReference?
+            stringVar = if(arg is AddressOf) {
+                arg.identifier
+            } else {
+                arg as? IdentifierReference
+            }
+            if(stringVar!=null) {
+                val vardecl = stringVar.targetVarDecl(program.namespace)!!
+                val string = vardecl.value!! as StringLiteralValue
+                if(string.value.length==1) {
+                    val firstCharEncoded = CompilationTarget.encodeString(string.value)[0]
+                    functionCallStatement.args.clear()
+                    functionCallStatement.args.add(NumericLiteralValue.optimalInteger(firstCharEncoded.toInt(), functionCallStatement.position))
+                    functionCallStatement.target = IdentifierReference(listOf("c64", "CHROUT"), functionCallStatement.target.position)
+                    vardeclsToRemove.add(vardecl)
+                    optimizationsDone++
+                    return functionCallStatement
+                } else if(string.value.length==2) {
+                    val firstTwoCharsEncoded = CompilationTarget.encodeString(string.value.take(2))
+                    val scope = AnonymousScope(mutableListOf(), functionCallStatement.position)
+                    scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("c64", "CHROUT"), functionCallStatement.target.position),
+                            mutableListOf(NumericLiteralValue.optimalInteger(firstTwoCharsEncoded[0].toInt(), functionCallStatement.position)),
+                            functionCallStatement.void, functionCallStatement.position))
+                    scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("c64", "CHROUT"), functionCallStatement.target.position),
+                            mutableListOf(NumericLiteralValue.optimalInteger(firstTwoCharsEncoded[1].toInt(), functionCallStatement.position)),
+                            functionCallStatement.void, functionCallStatement.position))
+                    vardeclsToRemove.add(vardecl)
+                    optimizationsDone++
+                    return scope
+                }
+            }
+        }
+
+        // if it calls a subroutine,
+        // and the first instruction in the subroutine is a jump, call that jump target instead
+        // if the first instruction in the subroutine is a return statement, replace with a nop instruction
+        val subroutine = functionCallStatement.target.targetSubroutine(program.namespace)
+        if(subroutine!=null) {
+            val first = subroutine.statements.asSequence().filterNot { it is VarDecl || it is Directive }.firstOrNull()
+            if(first is Jump && first.identifier!=null) {
+                optimizationsDone++
+                return FunctionCallStatement(first.identifier, functionCallStatement.args, functionCallStatement.void, functionCallStatement.position)
+            }
+            if(first is ReturnFromIrq || first is Return) {
+                optimizationsDone++
+                return NopStatement.insteadOf(functionCallStatement)
+            }
+        }
+
+        return super.visit(functionCallStatement)
+    }
+
+    override fun visit(functionCall: FunctionCall): Expression {
+        // if it calls a subroutine,
+        // and the first instruction in the subroutine is a jump, call that jump target instead
+        // if the first instruction in the subroutine is a return statement with constant value, replace with the constant value
+        val subroutine = functionCall.target.targetSubroutine(program.namespace)
+        if(subroutine!=null) {
+            val first = subroutine.statements.asSequence().filterNot { it is VarDecl || it is Directive }.firstOrNull()
+            if(first is Jump && first.identifier!=null) {
+                optimizationsDone++
+                return FunctionCall(first.identifier, functionCall.args, functionCall.position)
+            }
+            if(first is Return && first.value!=null) {
+                val constval = first.value?.constValue(program)
+                if(constval!=null)
+                    return constval
+            }
+        }
+        return super.visit(functionCall)
+    }
+
+    override fun visit(ifStatement: IfStatement): Statement {
+        super.visit(ifStatement)
+
+        if(ifStatement.truepart.containsNoCodeNorVars() && ifStatement.elsepart.containsNoCodeNorVars()) {
+            optimizationsDone++
+            return NopStatement.insteadOf(ifStatement)
+        }
+
+        if(ifStatement.truepart.containsNoCodeNorVars() && ifStatement.elsepart.containsCodeOrVars()) {
+            // invert the condition and move else part to true part
+            ifStatement.truepart = ifStatement.elsepart
+            ifStatement.elsepart = AnonymousScope(mutableListOf(), ifStatement.elsepart.position)
+            ifStatement.condition = PrefixExpression("not", ifStatement.condition, ifStatement.condition.position)
+            optimizationsDone++
+            return ifStatement
+        }
+
+        val constvalue = ifStatement.condition.constValue(program)
+        if(constvalue!=null) {
+            return if(constvalue.asBooleanValue){
+                // always true -> keep only if-part
+                printWarning("condition is always true", ifStatement.position)  // TODO don't warn this if the condition is just the single value 'true'
+                optimizationsDone++
+                ifStatement.truepart
+            } else {
+                // always false -> keep only else-part
+                printWarning("condition is always false", ifStatement.position)
+                optimizationsDone++
+                ifStatement.elsepart
+            }
+        }
+        return ifStatement
+    }
+
+    override fun visit(forLoop: ForLoop): Statement {
+        super.visit(forLoop)
+        if(forLoop.body.containsNoCodeNorVars()) {
+            // remove empty for loop
+            optimizationsDone++
+            return NopStatement.insteadOf(forLoop)
+        } else if(forLoop.body.statements.size==1) {
+            val loopvar = forLoop.body.statements[0] as? VarDecl
+            if(loopvar!=null && loopvar.name==forLoop.loopVar?.nameInSource?.singleOrNull()) {
+                // remove empty for loop
+                optimizationsDone++
+                return NopStatement.insteadOf(forLoop)
+            }
+        }
+
+
+        val range = forLoop.iterable as? RangeExpr
+        if(range!=null) {
+            if(range.size()==1) {
+                // for loop over a (constant) range of just a single value-- optimize the loop away
+                // loopvar/reg = range value , follow by block
+                val assignment = Assignment(AssignTarget(forLoop.loopRegister, forLoop.loopVar, null, null, forLoop.position), null, range.from, forLoop.position)
+                forLoop.body.statements.add(0, assignment)
+                optimizationsDone++
+                return forLoop.body
+            }
+        }
+        return forLoop
+    }
+
+    override fun visit(whileLoop: WhileLoop): Statement {
+        super.visit(whileLoop)
+        val constvalue = whileLoop.condition.constValue(program)
+        if(constvalue!=null) {
+            return if(constvalue.asBooleanValue){
+                // always true -> print a warning, and optimize into body + jump (if there are no continue and break statements)
+                printWarning("condition is always true", whileLoop.condition.position)
+                if(hasContinueOrBreak(whileLoop.body))
+                    return whileLoop
+                val backLabelName = "_prog8_back${whileLoop.position.line}"
+                val label = Label(backLabelName, whileLoop.condition.position)
+                whileLoop.body.statements.add(0, label)
+                whileLoop.body.statements.add(Jump(null,
+                        IdentifierReference(listOf(backLabelName), whileLoop.condition.position),
+                        null, whileLoop.condition.position))
+                optimizationsDone++
+                return whileLoop.body
+            } else {
+                // always false -> ditch whole statement
+                printWarning("condition is always false", whileLoop.condition.position)
+                optimizationsDone++
+                NopStatement.insteadOf(whileLoop)
+            }
+        }
+        return whileLoop
+    }
+
+    override fun visit(repeatLoop: RepeatLoop): Statement {
+        super.visit(repeatLoop)
+        val constvalue = repeatLoop.untilCondition.constValue(program)
+        if(constvalue!=null) {
+            return if(constvalue.asBooleanValue){
+                // always true -> keep only the statement block (if there are no continue and break statements)
+                printWarning("condition is always true", repeatLoop.untilCondition.position)
+                if(hasContinueOrBreak(repeatLoop.body))
+                    repeatLoop
+                else {
+                    optimizationsDone++
+                    repeatLoop.body
+                }
+            } else {
+                // always false -> print a warning, and optimize into body + jump (if there are no continue and break statements)
+                printWarning("condition is always false", repeatLoop.untilCondition.position)
+                if(hasContinueOrBreak(repeatLoop.body))
+                    return repeatLoop
+                val backLabelName = "_prog8_back${repeatLoop.position.line}"
+                val label = Label(backLabelName, repeatLoop.untilCondition.position)
+                repeatLoop.body.statements.add(0, label)
+                repeatLoop.body.statements.add(Jump(null,
+                        IdentifierReference(listOf(backLabelName), repeatLoop.untilCondition.position),
+                        null, repeatLoop.untilCondition.position))
+                optimizationsDone++
+                return repeatLoop.body
+            }
+        }
+        return repeatLoop
+    }
+
+    override fun visit(whenStatement: WhenStatement): Statement {
+        val choices = whenStatement.choices.toList()
+        for(choice in choices) {
+            if(choice.statements.containsNoCodeNorVars())
+                whenStatement.choices.remove(choice)
+        }
+        return super.visit(whenStatement)
+    }
+
+    private fun hasContinueOrBreak(scope: INameScope): Boolean {
+
+        class Searcher: IAstModifyingVisitor
+        {
+            var count=0
+
+            override fun visit(breakStmt: Break): Statement {
+                count++
+                return super.visit(breakStmt)
+            }
+
+            override fun visit(contStmt: Continue): Statement {
+                count++
+                return super.visit(contStmt)
+            }
+        }
+        val s=Searcher()
+        for(stmt in scope.statements) {
+            stmt.accept(s)
+            if(s.count>0)
+                return true
+        }
+        return s.count > 0
+    }
+
+    override fun visit(jump: Jump): Statement {
+        val subroutine = jump.identifier?.targetSubroutine(program.namespace)
+        if(subroutine!=null) {
+            // if the first instruction in the subroutine is another jump, shortcut this one
+            val first = subroutine.statements.asSequence().filterNot { it is VarDecl || it is Directive }.firstOrNull()
+            if(first is Jump) {
+                optimizationsDone++
+                return first
+            }
+        }
+
+        // if the jump is to the next statement, remove the jump
+        val scope = jump.definingScope()
+        val label = jump.identifier?.targetStatement(scope)
+        if(label!=null) {
+            if(scope.statements.indexOf(label) == scope.statements.indexOf(jump)+1) {
+                optimizationsDone++
+                return NopStatement.insteadOf(jump)
+            }
+        }
+
+        return jump
+    }
+
+    override fun visit(assignment: Assignment): Statement {
+        if(assignment.aug_op!=null)
+            throw AstException("augmented assignments should have been converted to normal assignments before this optimizer")
+
+        if(assignment.target isSameAs assignment.value) {
+            if(assignment.target.isNotMemory(program.namespace)) {
+                optimizationsDone++
+                return NopStatement.insteadOf(assignment)
+            }
+        }
+        val targetIDt = assignment.target.inferType(program, assignment)
+        if(!targetIDt.isKnown)
+            throw FatalAstException("can't infer type of assignment target")
+        val targetDt = targetIDt.typeOrElse(DataType.STRUCT)
+        val bexpr=assignment.value as? BinaryExpression
+        if(bexpr!=null) {
+            val cv = bexpr.right.constValue(program)?.number?.toDouble()
+            if (cv == null) {
+                if (bexpr.operator == "+" && targetDt != DataType.FLOAT) {
+                    if (bexpr.left isSameAs bexpr.right && assignment.target isSameAs bexpr.left) {
+                        bexpr.operator = "*"
+                        bexpr.right = NumericLiteralValue.optimalInteger(2, assignment.value.position)
+                        optimizationsDone++
+                        return assignment
+                    }
+                }
+            } else {
+                if (assignment.target isSameAs bexpr.left) {
+                    // remove assignments that have no effect  X=X , X+=0, X-=0, X*=1, X/=1, X//=1, A |= 0, A ^= 0, A<<=0, etc etc
+                    // A = A <operator> B
+                    val vardeclDt = (assignment.target.identifier?.targetVarDecl(program.namespace))?.type
+
+                    when (bexpr.operator) {
+                        "+" -> {
+                            if (cv == 0.0) {
+                                optimizationsDone++
+                                return NopStatement.insteadOf(assignment)
+                            } else if (targetDt in IntegerDatatypes && floor(cv) == cv) {
+                                if ((vardeclDt == VarDeclType.MEMORY && cv in 1.0..3.0) || (vardeclDt != VarDeclType.MEMORY && cv in 1.0..8.0)) {
+                                    // replace by several INCs (a bit less when dealing with memory targets)
+                                    val decs = AnonymousScope(mutableListOf(), assignment.position)
+                                    repeat(cv.toInt()) {
+                                        decs.statements.add(PostIncrDecr(assignment.target, "++", assignment.position))
+                                    }
+                                    return decs
+                                }
+                            }
+                        }
+                        "-" -> {
+                            if (cv == 0.0) {
+                                optimizationsDone++
+                                return NopStatement.insteadOf(assignment)
+                            } else if (targetDt in IntegerDatatypes && floor(cv) == cv) {
+                                if ((vardeclDt == VarDeclType.MEMORY && cv in 1.0..3.0) || (vardeclDt != VarDeclType.MEMORY && cv in 1.0..8.0)) {
+                                    // replace by several DECs (a bit less when dealing with memory targets)
+                                    val decs = AnonymousScope(mutableListOf(), assignment.position)
+                                    repeat(cv.toInt()) {
+                                        decs.statements.add(PostIncrDecr(assignment.target, "--", assignment.position))
+                                    }
+                                    return decs
+                                }
+                            }
+                        }
+                        "*" -> if (cv == 1.0) {
+                            optimizationsDone++
+                            return NopStatement.insteadOf(assignment)
+                        }
+                        "/" -> if (cv == 1.0) {
+                            optimizationsDone++
+                            return NopStatement.insteadOf(assignment)
+                        }
+                        "**" -> if (cv == 1.0) {
+                            optimizationsDone++
+                            return NopStatement.insteadOf(assignment)
+                        }
+                        "|" -> if (cv == 0.0) {
+                            optimizationsDone++
+                            return NopStatement.insteadOf(assignment)
+                        }
+                        "^" -> if (cv == 0.0) {
+                            optimizationsDone++
+                            return NopStatement.insteadOf(assignment)
+                        }
+                        "<<" -> {
+                            if (cv == 0.0) {
+                                optimizationsDone++
+                                return NopStatement.insteadOf(assignment)
+                            }
+                            if (((targetDt == DataType.UWORD || targetDt == DataType.WORD) && cv > 15.0) ||
+                                    ((targetDt == DataType.UBYTE || targetDt == DataType.BYTE) && cv > 7.0)) {
+                                assignment.value = NumericLiteralValue.optimalInteger(0, assignment.value.position)
+                                assignment.value.linkParents(assignment)
+                                optimizationsDone++
+                            } else {
+                                // replace by in-place lsl(...) call
+                                val scope = AnonymousScope(mutableListOf(), assignment.position)
+                                var numshifts = cv.toInt()
+                                while (numshifts > 0) {
+                                    scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("lsl"), assignment.position),
+                                            mutableListOf(bexpr.left), true, assignment.position))
+                                    numshifts--
+                                }
+                                optimizationsDone++
+                                return scope
+                            }
+                        }
+                        ">>" -> {
+                            if (cv == 0.0) {
+                                optimizationsDone++
+                                return NopStatement.insteadOf(assignment)
+                            }
+                            if ((targetDt == DataType.UWORD && cv > 15.0) || (targetDt == DataType.UBYTE && cv > 7.0)) {
+                                assignment.value = NumericLiteralValue.optimalInteger(0, assignment.value.position)
+                                assignment.value.linkParents(assignment)
+                                optimizationsDone++
+                            } else {
+                                // replace by in-place lsr(...) call
+                                val scope = AnonymousScope(mutableListOf(), assignment.position)
+                                var numshifts = cv.toInt()
+                                while (numshifts > 0) {
+                                    scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("lsr"), assignment.position),
+                                            mutableListOf(bexpr.left), true, assignment.position))
+                                    numshifts--
+                                }
+                                optimizationsDone++
+                                return scope
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+
+        return super.visit(assignment)
+    }
+
+    override fun visit(scope: AnonymousScope): Statement {
+        val linesToRemove = deduplicateAssignments(scope.statements)
+        if(linesToRemove.isNotEmpty()) {
+            linesToRemove.reversed().forEach{scope.statements.removeAt(it)}
+        }
+        return super.visit(scope)
+    }
+
+    override fun visit(label: Label): Statement {
+        // remove duplicate labels
+        val stmts = label.definingScope().statements
+        val startIdx = stmts.indexOf(label)
+        if(startIdx<(stmts.size-1) && stmts[startIdx+1] == label)
+            return NopStatement.insteadOf(label)
+
+        return super.visit(label)
+    }
+}
+
+
+
+internal class FlattenAnonymousScopesAndRemoveNops: IAstVisitor {
+    private var scopesToFlatten = mutableListOf<INameScope>()
+    private val nopStatements = mutableListOf<NopStatement>()
+
+    override fun visit(program: Program) {
+        super.visit(program)
+        for(scope in scopesToFlatten.reversed()) {
+            val namescope = scope.parent as INameScope
+            val idx = namescope.statements.indexOf(scope as Statement)
+            if(idx>=0) {
+                val nop = NopStatement.insteadOf(namescope.statements[idx])
+                nop.parent = namescope as Node
+                namescope.statements[idx] = nop
+                namescope.statements.addAll(idx, scope.statements)
+                scope.statements.forEach { it.parent = namescope }
+                visit(nop)
+            }
+        }
+
+        this.nopStatements.forEach {
+            it.definingScope().remove(it)
+        }
+    }
+
+    override fun visit(scope: AnonymousScope) {
+        if(scope.parent is INameScope) {
+            scopesToFlatten.add(scope)  // get rid of the anonymous scope
+        }
+
+        return super.visit(scope)
+    }
+
+    override fun visit(nopStatement: NopStatement) {
+        nopStatements.add(nopStatement)
+    }
+}

compiler/src/prog8/optimizing/ConstExprEvaluator.kt

@@ -1,288 +0,0 @@
-package prog8.optimizing
-
-import prog8.ast.*
-import prog8.compiler.HeapValues
-import kotlin.math.pow
-
-
-val associativeOperators = setOf("+", "*", "&", "|", "^", "or", "and", "xor", "==", "!=")
-
-
-class ConstExprEvaluator {
-
-    fun evaluate(left: LiteralValue, operator: String, right: LiteralValue): IExpression {
-        return when(operator) {
-            "+" -> plus(left, right)
-            "-" -> minus(left, right)
-            "*" -> multiply(left, right)
-            "/" -> divide(left, right)
-            "%" -> remainder(left, right)
-            "**" -> power(left, right)
-            "&" -> bitwiseand(left, right)
-            "|" -> bitwiseor(left, right)
-            "^" -> bitwisexor(left, right)
-            "and" -> logicaland(left, right)
-            "or" -> logicalor(left, right)
-            "xor" -> logicalxor(left, right)
-            "<" -> LiteralValue.fromBoolean(left < right, left.position)
-            ">" -> LiteralValue.fromBoolean(left > right, left.position)
-            "<=" -> LiteralValue.fromBoolean(left <= right, left.position)
-            ">=" -> LiteralValue.fromBoolean(left >= right, left.position)
-            "==" -> LiteralValue.fromBoolean(left == right, left.position)
-            "!=" -> LiteralValue.fromBoolean(left != right, left.position)
-            "<<" -> shiftedleft(left, right)
-            ">>" -> shiftedright(left, right)
-            else -> throw FatalAstException("const evaluation for invalid operator $operator")
-        }
-    }
-
-    private fun shiftedright(left: LiteralValue, amount: LiteralValue): IExpression {
-        if(left.asIntegerValue==null || amount.asIntegerValue==null)
-            throw ExpressionError("cannot compute $left >> $amount", left.position)
-        val result =
-                if(left.type==DataType.UBYTE || left.type==DataType.UWORD)
-                    left.asIntegerValue.ushr(amount.asIntegerValue)
-                else
-                    left.asIntegerValue.shr(amount.asIntegerValue)
-        return LiteralValue.fromNumber(result, left.type, left.position)
-    }
-
-    private fun shiftedleft(left: LiteralValue, amount: LiteralValue): IExpression {
-        if(left.asIntegerValue==null || amount.asIntegerValue==null)
-            throw ExpressionError("cannot compute $left << $amount", left.position)
-        val result = left.asIntegerValue.shl(amount.asIntegerValue)
-        return LiteralValue.fromNumber(result, left.type, left.position)
-    }
-
-    private fun logicalxor(left: LiteralValue, right: LiteralValue): LiteralValue {
-        val error = "cannot compute $left locical-bitxor $right"
-        return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.fromBoolean((left.asIntegerValue != 0) xor (right.asIntegerValue != 0), left.position)
-                right.floatvalue!=null -> LiteralValue.fromBoolean((left.asIntegerValue != 0) xor (right.floatvalue != 0.0), left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.fromBoolean((left.floatvalue != 0.0) xor (right.asIntegerValue != 0), left.position)
-                right.floatvalue!=null -> LiteralValue.fromBoolean((left.floatvalue != 0.0) xor (right.floatvalue != 0.0), left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            else -> throw ExpressionError(error, left.position)
-        }
-    }
-
-    private fun logicalor(left: LiteralValue, right: LiteralValue): LiteralValue {
-        val error = "cannot compute $left locical-or $right"
-        return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.fromBoolean(left.asIntegerValue != 0 || right.asIntegerValue != 0, left.position)
-                right.floatvalue!=null -> LiteralValue.fromBoolean(left.asIntegerValue != 0 || right.floatvalue != 0.0, left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.fromBoolean(left.floatvalue != 0.0 || right.asIntegerValue != 0, left.position)
-                right.floatvalue!=null -> LiteralValue.fromBoolean(left.floatvalue != 0.0 || right.floatvalue != 0.0, left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            else -> throw ExpressionError(error, left.position)
-        }
-    }
-
-    private fun logicaland(left: LiteralValue, right: LiteralValue): LiteralValue {
-        val error = "cannot compute $left locical-and $right"
-        return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.fromBoolean(left.asIntegerValue != 0 && right.asIntegerValue != 0, left.position)
-                right.floatvalue!=null -> LiteralValue.fromBoolean(left.asIntegerValue != 0 && right.floatvalue != 0.0, left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.fromBoolean(left.floatvalue != 0.0 && right.asIntegerValue != 0, left.position)
-                right.floatvalue!=null -> LiteralValue.fromBoolean(left.floatvalue != 0.0 && right.floatvalue != 0.0, left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            else -> throw ExpressionError(error, left.position)
-        }
-    }
-
-    private fun bitwisexor(left: LiteralValue, right: LiteralValue): LiteralValue {
-        if(left.type== DataType.UBYTE) {
-            if(right.asIntegerValue!=null) {
-                return LiteralValue(DataType.UBYTE, bytevalue = (left.bytevalue!!.toInt() xor (right.asIntegerValue and 255)).toShort(), position = left.position)
-            }
-        } else if(left.type== DataType.UWORD) {
-            if(right.asIntegerValue!=null) {
-                return LiteralValue(DataType.UWORD, wordvalue = left.wordvalue!! xor right.asIntegerValue, position = left.position)
-            }
-        }
-        throw ExpressionError("cannot calculate $left ^ $right", left.position)
-    }
-
-    private fun bitwiseor(left: LiteralValue, right: LiteralValue): LiteralValue {
-        if(left.type== DataType.UBYTE) {
-            if(right.asIntegerValue!=null) {
-                return LiteralValue(DataType.UBYTE, bytevalue = (left.bytevalue!!.toInt() or (right.asIntegerValue and 255)).toShort(), position = left.position)
-            }
-        } else if(left.type== DataType.UWORD) {
-            if(right.asIntegerValue!=null) {
-                return LiteralValue(DataType.UWORD, wordvalue = left.wordvalue!! or right.asIntegerValue, position = left.position)
-            }
-        }
-        throw ExpressionError("cannot calculate $left | $right", left.position)
-    }
-
-    private fun bitwiseand(left: LiteralValue, right: LiteralValue): LiteralValue {
-        if(left.type== DataType.UBYTE) {
-            if(right.asIntegerValue!=null) {
-                return LiteralValue(DataType.UBYTE, bytevalue = (left.bytevalue!!.toInt() or (right.asIntegerValue and 255)).toShort(), position = left.position)
-            }
-        } else if(left.type== DataType.UWORD) {
-            if(right.asIntegerValue!=null) {
-                return LiteralValue(DataType.UWORD, wordvalue = left.wordvalue!! or right.asIntegerValue, position = left.position)
-            }
-        }
-        throw ExpressionError("cannot calculate $left & $right", left.position)
-    }
-
-    private fun power(left: LiteralValue, right: LiteralValue): LiteralValue {
-        val error = "cannot calculate $left ** $right"
-        return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.optimalNumeric(left.asIntegerValue.toDouble().pow(right.asIntegerValue), left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.asIntegerValue.toDouble().pow(right.floatvalue), position = left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue.pow(right.asIntegerValue), position = left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue.pow(right.floatvalue), position = left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            else -> throw ExpressionError(error, left.position)
-        }
-    }
-
-    private fun plus(left: LiteralValue, right: LiteralValue): LiteralValue {
-        val error = "cannot add $left and $right"
-        return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.optimalNumeric(left.asIntegerValue + right.asIntegerValue, left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.asIntegerValue + right.floatvalue, position = left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue + right.asIntegerValue, position = left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue + right.floatvalue, position = left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            left.isString -> when {
-                right.isString -> {
-                    val newStr = left.strvalue!! + right.strvalue!!
-                    if(newStr.length > 255) throw ExpressionError("string too long", left.position)
-                    LiteralValue(DataType.STR, strvalue = newStr, position = left.position)
-                }
-                else -> throw ExpressionError(error, left.position)
-            }
-            else -> throw ExpressionError(error, left.position)
-        }
-    }
-
-    private fun minus(left: LiteralValue, right: LiteralValue): LiteralValue {
-        val error = "cannot subtract $left and $right"
-        return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.optimalNumeric(left.asIntegerValue - right.asIntegerValue, left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.asIntegerValue - right.floatvalue, position = left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue - right.asIntegerValue, position = left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue - right.floatvalue, position = left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            else -> throw ExpressionError(error, left.position)
-        }
-    }
-
-    private fun multiply(left: LiteralValue, right: LiteralValue): LiteralValue {
-        val error = "cannot multiply ${left.type} and ${right.type}"
-        return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue.optimalNumeric(left.asIntegerValue * right.asIntegerValue, left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.asIntegerValue * right.floatvalue, position = left.position)
-                right.isString -> {
-                    if(right.strvalue!!.length * left.asIntegerValue > 255) throw ExpressionError("string too long", left.position)
-                    LiteralValue(DataType.STR, strvalue = right.strvalue.repeat(left.asIntegerValue), position = left.position)
-                }
-                else -> throw ExpressionError(error, left.position)
-            }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue * right.asIntegerValue, position = left.position)
-                right.floatvalue!=null -> LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue * right.floatvalue, position = left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            else -> throw ExpressionError(error, left.position)
-        }
-    }
-
-    private fun divideByZeroError(pos: Position): Unit =
-            throw ExpressionError("division by zero", pos)
-
-    private fun divide(left: LiteralValue, right: LiteralValue): LiteralValue {
-        val error = "cannot divide $left by $right"
-        return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> {
-                    if(right.asIntegerValue==0) divideByZeroError(right.position)
-                    val result: Int = left.asIntegerValue / right.asIntegerValue
-                    LiteralValue.optimalNumeric(result, left.position)
-                }
-                right.floatvalue!=null -> {
-                    if(right.floatvalue==0.0) divideByZeroError(right.position)
-                    LiteralValue(DataType.FLOAT, floatvalue = left.asIntegerValue / right.floatvalue, position = left.position)
-                }
-                else -> throw ExpressionError(error, left.position)
-            }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> {
-                    if(right.asIntegerValue==0) divideByZeroError(right.position)
-                    LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue / right.asIntegerValue, position = left.position)
-                }
-                right.floatvalue!=null -> {
-                    if(right.floatvalue==0.0) divideByZeroError(right.position)
-                    LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue / right.floatvalue, position = left.position)
-                }
-                else -> throw ExpressionError(error, left.position)
-            }
-            else -> throw ExpressionError(error, left.position)
-        }
-    }
-
-    private fun remainder(left: LiteralValue, right: LiteralValue): LiteralValue {
-        val error = "cannot compute remainder of $left by $right"
-        return when {
-            left.asIntegerValue!=null -> when {
-                right.asIntegerValue!=null -> {
-                    if(right.asIntegerValue==0) divideByZeroError(right.position)
-                    LiteralValue.optimalNumeric(left.asIntegerValue.toDouble() % right.asIntegerValue.toDouble(), left.position)
-                }
-                right.floatvalue!=null -> {
-                    if(right.floatvalue==0.0) divideByZeroError(right.position)
-                    LiteralValue(DataType.FLOAT, floatvalue = left.asIntegerValue % right.floatvalue, position = left.position)
-                }
-                else -> throw ExpressionError(error, left.position)
-            }
-            left.floatvalue!=null -> when {
-                right.asIntegerValue!=null -> {
-                    if(right.asIntegerValue==0) divideByZeroError(right.position)
-                    LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue % right.asIntegerValue, position = left.position)
-                }
-                right.floatvalue!=null -> {
-                    if(right.floatvalue==0.0) divideByZeroError(right.position)
-                    LiteralValue(DataType.FLOAT, floatvalue = left.floatvalue % right.floatvalue, position = left.position)
-                }
-                else -> throw ExpressionError(error, left.position)
-            }
-            else -> throw ExpressionError(error, left.position)
-        }
-    }
-}

compiler/src/prog8/optimizing/StatementOptimizer.kt

@@ -1,627 +0,0 @@
-package prog8.optimizing
-
-import prog8.ast.*
-import prog8.compiler.target.c64.Petscii
-import prog8.functions.BuiltinFunctions
-import kotlin.math.floor
-
-
-/*
-    todo: subroutines with 1 or 2 byte args or 1 word arg can be converted to asm sub calling convention (args in registers)
-    todo analyse for unreachable code and remove that (f.i. code after goto or return that has no label so can never be jumped to) + print warning about this
-*/
-
-internal class StatementOptimizer(private val program: Program, private val optimizeInlining: Boolean) : IAstProcessor {
-    var optimizationsDone: Int = 0
-        private set
-    var scopesToFlatten = mutableListOf<INameScope>()
-
-    private val pureBuiltinFunctions = BuiltinFunctions.filter { it.value.pure }
-    private val callgraph = CallGraph(program)
-
-    companion object {
-        private var generatedLabelSequenceNumber = 0
-    }
-
-    override fun process(program: Program) {
-        removeUnusedCode(callgraph)
-        if(optimizeInlining) {
-            inlineSubroutines(callgraph)
-        }
-        super.process(program)
-    }
-
-    private fun inlineSubroutines(callgraph: CallGraph) {
-        val entrypoint = program.entrypoint()
-        program.modules.forEach {
-            callgraph.forAllSubroutines(it) { sub ->
-                if(sub!==entrypoint && !sub.isAsmSubroutine) {
-                    if (sub.statements.size <= 3 && !sub.expensiveToInline) {
-                        sub.calledBy.toList().forEach { caller -> inlineSubroutine(sub, caller) }
-                    } else if (sub.calledBy.size==1 && sub.statements.size < 50) {
-                        inlineSubroutine(sub, sub.calledBy[0])
-                    } else if(sub.calledBy.size<=3 && sub.statements.size < 10 && !sub.expensiveToInline) {
-                        sub.calledBy.toList().forEach { caller -> inlineSubroutine(sub, caller) }
-                    }
-                }
-            }
-        }
-    }
-
-    private fun inlineSubroutine(sub: Subroutine, caller: Node) {
-        // if the sub is called multiple times from the isSameAs scope, we can't inline (would result in duplicate definitions)
-        // (unless we add a sequence number to all vars/labels and references to them in the inlined code, but I skip that for now)
-        val scope = caller.definingScope()
-        if(sub.calledBy.count { it.definingScope()===scope } > 1)
-            return
-        if(caller !is IFunctionCall || caller !is IStatement || sub.statements.any { it is Subroutine })
-            return
-
-        if(sub.parameters.isEmpty() && sub.returntypes.isEmpty()) {
-            // sub without params and without return value can be easily inlined
-            val parent = caller.parent as INameScope
-            val inlined = AnonymousScope(sub.statements.toMutableList(), caller.position)
-            parent.statements[parent.statements.indexOf(caller)] = inlined
-            // replace return statements in the inlined sub by a jump to the end of it
-            var endlabel = inlined.statements.last() as? Label
-            if(endlabel==null) {
-                endlabel = makeLabel("_prog8_auto_sub_end", inlined.statements.last().position)
-                inlined.statements.add(endlabel)
-                endlabel.parent = inlined
-            }
-            val returns = inlined.statements.withIndex().filter { iv -> iv.value is Return }.map { iv -> Pair(iv.index, iv.value as Return)}
-            for(returnIdx in returns) {
-                assert(returnIdx.second.values.isEmpty())
-                val jump = Jump(null, IdentifierReference(listOf(endlabel.name), returnIdx.second.position), null, returnIdx.second.position)
-                inlined.statements[returnIdx.first] = jump
-            }
-            inlined.linkParents(caller.parent)
-            sub.calledBy.remove(caller)     // if there are no callers left, the sub will be removed automatically later
-            optimizationsDone++
-        } else {
-            // TODO inline subroutine that has params or returnvalues or both
-        }
-    }
-
-    private fun makeLabel(name: String, position: Position): Label {
-        generatedLabelSequenceNumber++
-        return Label("${name}_$generatedLabelSequenceNumber", position)
-    }
-
-    private fun removeUnusedCode(callgraph: CallGraph) {
-        // remove all subroutines that aren't called, or are empty
-        val removeSubroutines = mutableSetOf<Subroutine>()
-        val entrypoint = program.entrypoint()
-        program.modules.forEach {
-            callgraph.forAllSubroutines(it) { sub ->
-                if (sub !== entrypoint && !sub.keepAlways && (sub.calledBy.isEmpty() || (sub.containsNoCodeNorVars() && !sub.isAsmSubroutine)))
-                    removeSubroutines.add(sub)
-            }
-        }
-
-        if (removeSubroutines.isNotEmpty()) {
-            removeSubroutines.forEach {
-                it.definingScope().remove(it)
-            }
-        }
-
-        val removeBlocks = mutableSetOf<Block>()
-        program.modules.flatMap { it.statements }.filterIsInstance<Block>().forEach { block ->
-            if (block.containsNoCodeNorVars() && "force_output" !in block.options())
-                removeBlocks.add(block)
-        }
-
-        if (removeBlocks.isNotEmpty()) {
-            removeBlocks.forEach { it.definingScope().remove(it) }
-        }
-
-        // remove modules that are not imported, or are empty (unless it's a library modules)
-        val removeModules = mutableSetOf<Module>()
-        program.modules.forEach {
-            if (!it.isLibraryModule && (it.importedBy.isEmpty() || it.containsNoCodeNorVars()))
-                removeModules.add(it)
-        }
-
-        if (removeModules.isNotEmpty()) {
-            program.modules.removeAll(removeModules)
-        }
-    }
-
-    override fun process(block: Block): IStatement {
-        if("force_output" !in block.options()) {
-            if (block.containsNoCodeNorVars()) {
-                optimizationsDone++
-                printWarning("removing empty block '${block.name}'", block.position)
-                return NopStatement(block.position)
-            }
-
-            if (block !in callgraph.usedSymbols) {
-                optimizationsDone++
-                printWarning("removing unused block '${block.name}'", block.position)
-                return NopStatement(block.position)  // remove unused block
-            }
-        }
-
-        return super.process(block)
-    }
-
-    override fun process(subroutine: Subroutine): IStatement {
-        super.process(subroutine)
-        val forceOutput = "force_output" in subroutine.definingBlock().options()
-        if(subroutine.asmAddress==null && !forceOutput) {
-            if(subroutine.containsNoCodeNorVars()) {
-                printWarning("removing empty subroutine '${subroutine.name}'", subroutine.position)
-                optimizationsDone++
-                return NopStatement(subroutine.position)
-            }
-        }
-
-        val linesToRemove = deduplicateAssignments(subroutine.statements)
-        if(linesToRemove.isNotEmpty()) {
-            linesToRemove.reversed().forEach{subroutine.statements.removeAt(it)}
-        }
-
-        if(subroutine.canBeAsmSubroutine) {
-            optimizationsDone++
-            return subroutine.intoAsmSubroutine()   // TODO this doesn't work yet due to parameter vardecl issue
-
-            // TODO fix parameter passing so this also works:
-//            asmsub aa(byte arg @ Y) -> clobbers() -> () {
-//                byte local = arg            ; @todo fix 'undefined symbol arg' by some sort of alias name for the parameter
-//                A=44
-//            }
-
-        }
-
-        if(subroutine !in callgraph.usedSymbols && !forceOutput) {
-            printWarning("removing unused subroutine '${subroutine.name}'", subroutine.position)
-            optimizationsDone++
-            return NopStatement(subroutine.position)        // remove unused subroutine
-        }
-
-        return subroutine
-    }
-
-    override fun process(decl: VarDecl): IStatement {
-        val forceOutput = "force_output" in decl.definingBlock().options()
-        if(decl !in callgraph.usedSymbols && !forceOutput) {
-            if(decl.type!=VarDeclType.CONST)
-                printWarning("removing unused variable '${decl.name}'", decl.position)
-            optimizationsDone++
-            return NopStatement(decl.position)        // remove unused variable
-        }
-
-        return super.process(decl)
-    }
-
-    private fun deduplicateAssignments(statements: List<IStatement>): MutableList<Int> {
-        // removes 'duplicate' assignments that assign the isSameAs target
-        val linesToRemove = mutableListOf<Int>()
-        var previousAssignmentLine: Int? = null
-        for (i in 0 until statements.size) {
-            val stmt = statements[i] as? Assignment
-            if (stmt != null && stmt.value is LiteralValue) {
-                if (previousAssignmentLine == null) {
-                    previousAssignmentLine = i
-                    continue
-                } else {
-                    val prev = statements[previousAssignmentLine] as Assignment
-                    if (prev.targets.size == 1 && stmt.targets.size == 1 && prev.targets[0].isSameAs(stmt.targets[0], program)) {
-                        // get rid of the previous assignment, if the target is not MEMORY
-                        if (prev.targets[0].isNotMemory(program.namespace))
-                            linesToRemove.add(previousAssignmentLine)
-                    }
-                    previousAssignmentLine = i
-                }
-            } else
-                previousAssignmentLine = null
-        }
-        return linesToRemove
-    }
-
-    override fun process(functionCallStatement: FunctionCallStatement): IStatement {
-        if(functionCallStatement.target.nameInSource.size==1 && functionCallStatement.target.nameInSource[0] in BuiltinFunctions) {
-            val functionName = functionCallStatement.target.nameInSource[0]
-            if (functionName in pureBuiltinFunctions) {
-                printWarning("statement has no effect (function return value is discarded)", functionCallStatement.position)
-                optimizationsDone++
-                return NopStatement(functionCallStatement.position)
-            }
-        }
-
-        if(functionCallStatement.target.nameInSource==listOf("c64scr", "print") ||
-                functionCallStatement.target.nameInSource==listOf("c64scr", "print_p")) {
-            // printing a literal string of just 2 or 1 characters is replaced by directly outputting those characters
-            if(functionCallStatement.arglist.single() is LiteralValue)
-                throw AstException("string argument should be on heap already")
-            val stringVar = functionCallStatement.arglist.single() as? IdentifierReference
-            if(stringVar!=null) {
-                val heapId = stringVar.heapId(program.namespace)
-                val string = program.heap.get(heapId).str!!
-                if(string.length==1) {
-                    val petscii = Petscii.encodePetscii(string, true)[0]
-                    functionCallStatement.arglist.clear()
-                    functionCallStatement.arglist.add(LiteralValue.optimalInteger(petscii, functionCallStatement.position))
-                    functionCallStatement.target = IdentifierReference(listOf("c64", "CHROUT"), functionCallStatement.target.position)
-                    optimizationsDone++
-                    return functionCallStatement
-                } else if(string.length==2) {
-                    val petscii = Petscii.encodePetscii(string, true)
-                    val scope = AnonymousScope(mutableListOf(), functionCallStatement.position)
-                    scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("c64", "CHROUT"), functionCallStatement.target.position),
-                            mutableListOf(LiteralValue.optimalInteger(petscii[0], functionCallStatement.position)), functionCallStatement.position))
-                    scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("c64", "CHROUT"), functionCallStatement.target.position),
-                            mutableListOf(LiteralValue.optimalInteger(petscii[1], functionCallStatement.position)), functionCallStatement.position))
-                    optimizationsDone++
-                    return scope
-                }
-            }
-        }
-
-        // if it calls a subroutine,
-        // and the first instruction in the subroutine is a jump, call that jump target instead
-        // if the first instruction in the subroutine is a return statement, replace with a nop instruction
-        val subroutine = functionCallStatement.target.targetSubroutine(program.namespace)
-        if(subroutine!=null) {
-            val first = subroutine.statements.asSequence().filterNot { it is VarDecl || it is Directive }.firstOrNull()
-            if(first is Jump && first.identifier!=null) {
-                optimizationsDone++
-                return FunctionCallStatement(first.identifier, functionCallStatement.arglist, functionCallStatement.position)
-            }
-            if(first is ReturnFromIrq || first is Return) {
-                optimizationsDone++
-                return NopStatement(functionCallStatement.position)
-            }
-        }
-
-        return super.process(functionCallStatement)
-    }
-
-    override fun process(functionCall: FunctionCall): IExpression {
-        // if it calls a subroutine,
-        // and the first instruction in the subroutine is a jump, call that jump target instead
-        // if the first instruction in the subroutine is a return statement with constant value, replace with the constant value
-        val subroutine = functionCall.target.targetSubroutine(program.namespace)
-        if(subroutine!=null) {
-            val first = subroutine.statements.asSequence().filterNot { it is VarDecl || it is Directive }.firstOrNull()
-            if(first is Jump && first.identifier!=null) {
-                optimizationsDone++
-                return FunctionCall(first.identifier, functionCall.arglist, functionCall.position)
-            }
-            if(first is Return && first.values.size==1) {
-                val constval = first.values[0].constValue(program)
-                if(constval!=null)
-                    return constval
-            }
-        }
-        return super.process(functionCall)
-    }
-
-    override fun process(ifStatement: IfStatement): IStatement {
-        super.process(ifStatement)
-
-        if(ifStatement.truepart.containsNoCodeNorVars() && ifStatement.elsepart.containsNoCodeNorVars()) {
-            optimizationsDone++
-            return NopStatement(ifStatement.position)
-        }
-
-        if(ifStatement.truepart.containsNoCodeNorVars() && ifStatement.elsepart.containsCodeOrVars()) {
-            // invert the condition and move else part to true part
-            ifStatement.truepart = ifStatement.elsepart
-            ifStatement.elsepart = AnonymousScope(mutableListOf(), ifStatement.elsepart.position)
-            ifStatement.condition = PrefixExpression("not", ifStatement.condition, ifStatement.condition.position)
-            optimizationsDone++
-            return ifStatement
-        }
-
-        val constvalue = ifStatement.condition.constValue(program)
-        if(constvalue!=null) {
-            return if(constvalue.asBooleanValue){
-                // always true -> keep only if-part
-                printWarning("condition is always true", ifStatement.position)
-                optimizationsDone++
-                ifStatement.truepart
-            } else {
-                // always false -> keep only else-part
-                printWarning("condition is always false", ifStatement.position)
-                optimizationsDone++
-                ifStatement.elsepart
-            }
-        }
-        return ifStatement
-    }
-
-    override fun process(forLoop: ForLoop): IStatement {
-        super.process(forLoop)
-        if(forLoop.body.containsNoCodeNorVars()) {
-            // remove empty for loop
-            optimizationsDone++
-            return NopStatement(forLoop.position)
-        } else if(forLoop.body.statements.size==1) {
-            val loopvar = forLoop.body.statements[0] as? VarDecl
-            if(loopvar!=null && loopvar.name==forLoop.loopVar?.nameInSource?.singleOrNull()) {
-                // remove empty for loop
-                optimizationsDone++
-                return NopStatement(forLoop.position)
-            }
-        }
-
-
-        val range = forLoop.iterable as? RangeExpr
-        if(range!=null) {
-            if(range.size()==1) {
-                // for loop over a (constant) range of just a single value-- optimize the loop away
-                // loopvar/reg = range value , follow by block
-                val assignment = Assignment(listOf(AssignTarget(forLoop.loopRegister, forLoop.loopVar, null, null, forLoop.position)), null, range.from, forLoop.position)
-                forLoop.body.statements.add(0, assignment)
-                optimizationsDone++
-                return forLoop.body
-            }
-        }
-        return forLoop
-    }
-
-    override fun process(whileLoop: WhileLoop): IStatement {
-        super.process(whileLoop)
-        val constvalue = whileLoop.condition.constValue(program)
-        if(constvalue!=null) {
-            return if(constvalue.asBooleanValue){
-                // always true -> print a warning, and optimize into body + jump (if there are no continue and break statements)
-                printWarning("condition is always true", whileLoop.position)
-                if(hasContinueOrBreak(whileLoop.body))
-                    return whileLoop
-                val label = Label("__back", whileLoop.condition.position)
-                whileLoop.body.statements.add(0, label)
-                whileLoop.body.statements.add(Jump(null,
-                        IdentifierReference(listOf("__back"), whileLoop.condition.position),
-                        null, whileLoop.condition.position))
-                optimizationsDone++
-                return whileLoop.body
-            } else {
-                // always false -> ditch whole statement
-                printWarning("condition is always false", whileLoop.position)
-                optimizationsDone++
-                NopStatement(whileLoop.position)
-            }
-        }
-        return whileLoop
-    }
-
-    override fun process(repeatLoop: RepeatLoop): IStatement {
-        super.process(repeatLoop)
-        val constvalue = repeatLoop.untilCondition.constValue(program)
-        if(constvalue!=null) {
-            return if(constvalue.asBooleanValue){
-                // always true -> keep only the statement block (if there are no continue and break statements)
-                printWarning("condition is always true", repeatLoop.position)
-                if(hasContinueOrBreak(repeatLoop.body))
-                    repeatLoop
-                else {
-                    optimizationsDone++
-                    repeatLoop.body
-                }
-            } else {
-                // always false -> print a warning, and optimize into body + jump (if there are no continue and break statements)
-                printWarning("condition is always false", repeatLoop.position)
-                if(hasContinueOrBreak(repeatLoop.body))
-                    return repeatLoop
-                val label = Label("__back", repeatLoop.untilCondition.position)
-                repeatLoop.body.statements.add(0, label)
-                repeatLoop.body.statements.add(Jump(null,
-                        IdentifierReference(listOf("__back"), repeatLoop.untilCondition.position),
-                        null, repeatLoop.untilCondition.position))
-                optimizationsDone++
-                return repeatLoop.body
-            }
-        }
-        return repeatLoop
-    }
-
-    private fun hasContinueOrBreak(scope: INameScope): Boolean {
-
-        class Searcher:IAstProcessor
-        {
-            var count=0
-
-            override fun process(breakStmt: Break): IStatement {
-                count++
-                return super.process(breakStmt)
-            }
-
-            override fun process(contStmt: Continue): IStatement {
-                count++
-                return super.process(contStmt)
-            }
-        }
-        val s=Searcher()
-        for(stmt in scope.statements) {
-            stmt.process(s)
-            if(s.count>0)
-                return true
-        }
-        return s.count > 0
-    }
-
-    override fun process(jump: Jump): IStatement {
-        val subroutine = jump.identifier?.targetSubroutine(program.namespace)
-        if(subroutine!=null) {
-            // if the first instruction in the subroutine is another jump, shortcut this one
-            val first = subroutine.statements.asSequence().filterNot { it is VarDecl || it is Directive }.firstOrNull()
-            if(first is Jump) {
-                optimizationsDone++
-                return first
-            }
-        }
-
-        // if the jump is to the next statement, remove the jump
-        val scope = jump.definingScope()
-        val label = jump.identifier?.targetStatement(scope)
-        if(label!=null) {
-            if(scope.statements.indexOf(label) == scope.statements.indexOf(jump)+1) {
-                optimizationsDone++
-                return NopStatement(jump.position)
-            }
-        }
-
-        return jump
-    }
-
-    override fun process(assignment: Assignment): IStatement {
-        if(assignment.aug_op!=null)
-            throw AstException("augmented assignments should have been converted to normal assignments before this optimizer")
-
-        if(assignment.targets.size==1) {
-            val target=assignment.targets[0]
-            if(target isSameAs assignment.value) {
-                optimizationsDone++
-                return NopStatement(assignment.position)
-            }
-            val targetDt = target.inferType(program, assignment)
-            val bexpr=assignment.value as? BinaryExpression
-            if(bexpr!=null) {
-                val cv = bexpr.right.constValue(program)?.asNumericValue?.toDouble()
-                if(cv==null) {
-                    if(bexpr.operator=="+" && targetDt!=DataType.FLOAT) {
-                        if (bexpr.left isSameAs bexpr.right && target isSameAs bexpr.left) {
-                            bexpr.operator = "*"
-                            bexpr.right = LiteralValue.optimalInteger(2, assignment.value.position)
-                            optimizationsDone++
-                            return assignment
-                        }
-                    }
-                } else {
-                    if (target isSameAs bexpr.left) {
-                        // remove assignments that have no effect  X=X , X+=0, X-=0, X*=1, X/=1, X//=1, A |= 0, A ^= 0, A<<=0, etc etc
-                        // A = A <operator> B
-                        val vardeclDt = (target.identifier?.targetVarDecl(program.namespace))?.type
-
-                        when (bexpr.operator) {
-                            "+" -> {
-                                if (cv == 0.0) {
-                                    optimizationsDone++
-                                    return NopStatement(assignment.position)
-                                } else if (targetDt in IntegerDatatypes && floor(cv) == cv) {
-                                    if((vardeclDt == VarDeclType.MEMORY && cv in 1.0..3.0) || (vardeclDt!=VarDeclType.MEMORY && cv in 1.0..8.0)) {
-                                        // replace by several INCs (a bit less when dealing with memory targets)
-                                        val decs = AnonymousScope(mutableListOf(), assignment.position)
-                                        repeat(cv.toInt()) {
-                                            decs.statements.add(PostIncrDecr(target, "++", assignment.position))
-                                        }
-                                        return decs
-                                    }
-                                }
-                            }
-                            "-" -> {
-                                if (cv == 0.0) {
-                                    optimizationsDone++
-                                    return NopStatement(assignment.position)
-                                } else if (targetDt in IntegerDatatypes && floor(cv) == cv) {
-                                    if((vardeclDt == VarDeclType.MEMORY && cv in 1.0..3.0) || (vardeclDt!=VarDeclType.MEMORY && cv in 1.0..8.0)) {
-                                        // replace by several DECs (a bit less when dealing with memory targets)
-                                        val decs = AnonymousScope(mutableListOf(), assignment.position)
-                                        repeat(cv.toInt()) {
-                                            decs.statements.add(PostIncrDecr(target, "--", assignment.position))
-                                        }
-                                        return decs
-                                    }
-                                }
-                            }
-                            "*" -> if (cv == 1.0) {
-                                optimizationsDone++
-                                return NopStatement(assignment.position)
-                            }
-                            "/" -> if (cv == 1.0) {
-                                optimizationsDone++
-                                return NopStatement(assignment.position)
-                            }
-                            "**" -> if (cv == 1.0) {
-                                optimizationsDone++
-                                return NopStatement(assignment.position)
-                            }
-                            "|" -> if (cv == 0.0) {
-                                optimizationsDone++
-                                return NopStatement(assignment.position)
-                            }
-                            "^" -> if (cv == 0.0) {
-                                optimizationsDone++
-                                return NopStatement(assignment.position)
-                            }
-                            "<<" -> {
-                                if (cv == 0.0) {
-                                    optimizationsDone++
-                                    return NopStatement(assignment.position)
-                                }
-                                if (((targetDt == DataType.UWORD || targetDt == DataType.WORD) && cv > 15.0) ||
-                                        ((targetDt == DataType.UBYTE || targetDt == DataType.BYTE) && cv > 7.0)) {
-                                    assignment.value = LiteralValue.optimalInteger(0, assignment.value.position)
-                                    assignment.value.linkParents(assignment)
-                                    optimizationsDone++
-                                } else {
-                                    // replace by in-place lsl(...) call
-                                    val scope = AnonymousScope(mutableListOf(), assignment.position)
-                                    var numshifts = cv.toInt()
-                                    while (numshifts > 0) {
-                                        scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("lsl"), assignment.position), mutableListOf(bexpr.left), assignment.position))
-                                        numshifts--
-                                    }
-                                    optimizationsDone++
-                                    return scope
-                                }
-                            }
-                            ">>" -> {
-                                if (cv == 0.0) {
-                                    optimizationsDone++
-                                    return NopStatement(assignment.position)
-                                }
-                                if (((targetDt == DataType.UWORD || targetDt == DataType.WORD) && cv > 15.0) ||
-                                        ((targetDt == DataType.UBYTE || targetDt == DataType.BYTE) && cv > 7.0)) {
-                                    assignment.value = LiteralValue.optimalInteger(0, assignment.value.position)
-                                    assignment.value.linkParents(assignment)
-                                    optimizationsDone++
-                                } else {
-                                    // replace by in-place lsr(...) call
-                                    val scope = AnonymousScope(mutableListOf(), assignment.position)
-                                    var numshifts = cv.toInt()
-                                    while (numshifts > 0) {
-                                        scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("lsr"), assignment.position), mutableListOf(bexpr.left), assignment.position))
-                                        numshifts--
-                                    }
-                                    optimizationsDone++
-                                    return scope
-                                }
-                            }
-                        }
-                    }
-                }
-            }
-        }
-
-        return super.process(assignment)
-    }
-
-    override fun process(scope: AnonymousScope): IStatement {
-        val linesToRemove = deduplicateAssignments(scope.statements)
-        if(linesToRemove.isNotEmpty()) {
-            linesToRemove.reversed().forEach{scope.statements.removeAt(it)}
-        }
-
-        if(scope.parent is INameScope) {
-            scopesToFlatten.add(scope)  // get rid of the anonymous scope
-        }
-
-        return super.process(scope)
-    }
-
-    override fun process(label: Label): IStatement {
-        // remove duplicate labels
-        val stmts = label.definingScope().statements
-        val startIdx = stmts.indexOf(label)
-        if(startIdx<(stmts.size-1) && stmts[startIdx+1] == label)
-            return NopStatement(label.position)
-
-        return super.process(label)
-    }
-}
-
-
-

compiler/src/prog8/parser/ModuleParsing.kt

@@ -1,7 +1,15 @@
 package prog8.parser
 
 import org.antlr.v4.runtime.*
-import prog8.ast.*
+import prog8.ast.Module
+import prog8.ast.Program
+import prog8.ast.antlr.toAst
+import prog8.ast.base.Position
+import prog8.ast.base.SyntaxError
+import prog8.ast.base.checkImportedValid
+import prog8.ast.statements.Directive
+import prog8.ast.statements.DirectiveArg
+import prog8.pathFrom
 import java.io.InputStream
 import java.nio.file.Files
 import java.nio.file.Path
@@ -40,13 +48,13 @@ internal fun importModule(program: Program, filePath: Path): Module {
         throw ParsingFailedError("No such file: $filePath")
 
     val input = CharStreams.fromPath(filePath)
-    return importModule(program, input, filePath, filePath.parent==null)
+    return importModule(program, input, filePath, false)
 }
 
 internal fun importLibraryModule(program: Program, name: String): Module? {
     val import = Directive("%import", listOf(
-            DirectiveArg("", name, 42, position = Position("<<<implicit-import>>>", 0, 0 ,0))
-    ), Position("<<<implicit-import>>>", 0, 0 ,0))
+            DirectiveArg("", name, 42, position = Position("<<<implicit-import>>>", 0, 0, 0))
+    ), Position("<<<implicit-import>>>", 0, 0, 0))
     return executeImportDirective(program, import, Paths.get(""))
 }
 
@@ -71,7 +79,7 @@ internal fun importModule(program: Program, stream: CharStream, modulePath: Path
     moduleAst.linkParents(program.namespace)
     program.modules.add(moduleAst)
 
-    // process additional imports
+    // accept additional imports
     val lines = moduleAst.statements.toMutableList()
     lines.asSequence()
          .mapIndexed { i, it -> Pair(i, it) }
@@ -84,18 +92,18 @@ internal fun importModule(program: Program, stream: CharStream, modulePath: Path
 
 private fun discoverImportedModuleFile(name: String, source: Path, position: Position?): Path {
     val fileName = "$name.p8"
-    val locations = mutableListOf(Paths.get(source.parent.toString()))
+    val locations = mutableListOf(source.parent)
 
     val propPath = System.getProperty("prog8.libdir")
     if(propPath!=null)
-        locations.add(Paths.get(propPath))
+        locations.add(pathFrom(propPath))
     val envPath = System.getenv("PROG8_LIBDIR")
     if(envPath!=null)
-        locations.add(Paths.get(envPath))
+        locations.add(pathFrom(envPath))
     locations.add(Paths.get(Paths.get("").toAbsolutePath().toString(), "prog8lib"))
 
     locations.forEach {
-        val file = Paths.get(it.toString(), fileName)
+        val file = pathFrom(it.toString(), fileName)
         if (Files.isReadable(file)) return file
     }
 
@@ -113,7 +121,7 @@ private fun executeImportDirective(program: Program, import: Directive, source:
     if(existing!=null)
         return null
 
-    val resource = tryGetEmbeddedResource(moduleName+".p8")
+    val resource = tryGetEmbeddedResource("$moduleName.p8")
     val importedModule =
         if(resource!=null) {
             // load the module from the embedded resource

compiler/src/prog8/stackvm/Memory.kt

@@ -1,102 +0,0 @@
-package prog8.stackvm
-
-import prog8.compiler.target.c64.Mflpt5
-import prog8.compiler.target.c64.Petscii
-import kotlin.math.abs
-
-class Memory {
-    private val mem = ShortArray(65536)         // shorts because byte is signed and we store values 0..255
-
-    fun getUByte(address: Int): Short {
-        return mem[address]
-    }
-
-    fun getSByte(address: Int): Short {
-        val ubyte = getUByte(address)
-        if(ubyte <= 127)
-            return ubyte
-        return (-((ubyte.toInt() xor 255)+1)).toShort()   // 2's complement
-    }
-
-    fun setUByte(address: Int, value: Short) {
-        if(value !in 0..255)
-            throw VmExecutionException("ubyte value out of range")
-        mem[address] = value
-    }
-
-    fun setSByte(address: Int, value: Short) {
-        if(value !in -128..127) throw VmExecutionException("byte value out of range")
-        if(value>=0)
-            mem[address] = value
-        else
-            mem[address] = ((abs(value.toInt()) xor 255)+1).toShort()        // 2's complement
-    }
-
-    fun getUWord(address: Int): Int {
-        return mem[address] + 256*mem[address+1]
-    }
-
-    fun getSWord(address: Int): Int {
-        val uword = getUWord(address)
-        if(uword <= 32767)
-            return uword
-        return -((uword xor 65535)+1)   // 2's complement
-    }
-
-    fun setUWord(address: Int, value: Int) {
-        if(value !in 0..65535)
-            throw VmExecutionException("uword value out of range")
-        mem[address] = value.and(255).toShort()
-        mem[address+1] = (value / 256).toShort()
-    }
-
-    fun setSWord(address: Int, value: Int) {
-        if(value !in -32768..32767) throw VmExecutionException("word value out of range")
-        if(value>=0)
-            setUWord(address, value)
-        else
-            setUWord(address, (abs(value) xor 65535)+1)        // 2's complement
-    }
-
-    fun setFloat(address: Int, value: Double) {
-        val mflpt5 = Mflpt5.fromNumber(value)
-        mem[address] = mflpt5.b0
-        mem[address+1] = mflpt5.b1
-        mem[address+2] = mflpt5.b2
-        mem[address+3] = mflpt5.b3
-        mem[address+4] = mflpt5.b4
-    }
-
-    fun getFloat(address: Int): Double {
-        return Mflpt5(mem[address], mem[address + 1], mem[address + 2], mem[address + 3], mem[address + 4]).toDouble()
-    }
-
-    fun setString(address: Int, str: String) {
-        // lowercase PETSCII
-        val petscii = Petscii.encodePetscii(str, true)
-        var addr = address
-        for (c in petscii) mem[addr++] = c
-        mem[addr] = 0
-    }
-
-    fun getString(strAddress: Int): String {
-        // lowercase PETSCII
-        val petscii = mutableListOf<Short>()
-        var addr = strAddress
-        while(true) {
-            val byte = mem[addr++]
-            if(byte==0.toShort()) break
-            petscii.add(byte)
-        }
-        return Petscii.decodePetscii(petscii, true)
-    }
-
-    fun clear() {
-        for(i in 0..65535) mem[i]=0
-    }
-
-    fun copy(from: Int, to: Int, numbytes: Int) {
-        for(i in 0 until numbytes)
-            mem[to+i] = mem[from+i]
-    }
-}

compiler/src/prog8/stackvm/Program.kt

@@ -1,296 +0,0 @@
-package prog8.stackvm
-
-import prog8.ast.*
-import prog8.compiler.RuntimeValue
-import prog8.compiler.HeapValues
-import prog8.compiler.IntegerOrAddressOf
-import prog8.compiler.intermediate.*
-import java.io.File
-import java.util.*
-import java.util.regex.Pattern
-
-class Program (val name: String,
-               val program: MutableList<Instruction>,
-               val variables: Map<String, RuntimeValue>,
-               val memoryPointers: Map<String, Pair<Int, DataType>>,
-               val labels: Map<String, Int>,
-               val memory: Map<Int, List<RuntimeValue>>,
-               val heap: HeapValues)
-{
-    init {
-        // add end of program marker and some sentinel instructions, to correctly connect all others
-        program.add(LabelInstr("____program_end", false))
-        program.add(Instruction(Opcode.TERMINATE))
-        program.add(Instruction(Opcode.NOP))
-    }
-
-    companion object {
-        fun load(filename: String): Program {
-            val lines = File(filename).readLines().withIndex().iterator()
-            val memory = mutableMapOf<Int, List<RuntimeValue>>()
-            val heap = HeapValues()
-            val program = mutableListOf<Instruction>()
-            val variables = mutableMapOf<String, RuntimeValue>()
-            val memoryPointers = mutableMapOf<String, Pair<Int, DataType>>()
-            val labels = mutableMapOf<String, Int>()
-
-            while(lines.hasNext()) {
-                val (lineNr, line) = lines.next()
-                if(line.startsWith(';') || line.isEmpty())
-                    continue
-                else if(line=="%memory")
-                    loadMemory(lines, memory)
-                else if(line=="%heap")
-                    loadHeap(lines, heap)
-                else if(line.startsWith("%block "))
-                    loadBlock(lines, heap, program, variables, memoryPointers, labels)
-                else throw VmExecutionException("syntax error at line ${lineNr + 1}")
-            }
-            return Program(filename, program, variables, memoryPointers, labels, memory, heap)
-        }
-
-        private fun loadBlock(lines: Iterator<IndexedValue<String>>,
-                              heap: HeapValues,
-                              program: MutableList<Instruction>,
-                              variables: MutableMap<String, RuntimeValue>,
-                              memoryPointers: MutableMap<String, Pair<Int, DataType>>,
-                              labels: MutableMap<String, Int>)
-        {
-            while(true) {
-                val (_, line) = lines.next()
-                if(line.isEmpty())
-                    continue
-                else if(line=="%end_block")
-                    return
-                else if(line=="%variables")
-                    loadVars(lines, variables)
-                else if(line=="%memorypointers")
-                    loadMemoryPointers(lines, memoryPointers, heap)
-                else if(line=="%instructions") {
-                    val (blockInstructions, blockLabels) = loadInstructions(lines, heap)
-                    val baseIndex = program.size
-                    program.addAll(blockInstructions)
-                    val labelsWithIndex = blockLabels.mapValues { baseIndex+blockInstructions.indexOf(it.value) }
-                    labels.putAll(labelsWithIndex)
-                }
-            }
-        }
-
-        private fun loadHeap(lines: Iterator<IndexedValue<String>>, heap: HeapValues) {
-            val splitpattern = Pattern.compile("\\s+")
-            val heapvalues = mutableListOf<Triple<Int, DataType, String>>()
-            while(true) {
-                val (_, line) = lines.next()
-                if (line == "%end_heap")
-                    break
-                val parts = line.split(splitpattern, limit=3)
-                val value = Triple(parts[0].toInt(), DataType.valueOf(parts[1].toUpperCase()), parts[2])
-                heapvalues.add(value)
-            }
-            heapvalues.sortedBy { it.first }.forEach {
-                when(it.second) {
-                    DataType.STR, DataType.STR_S -> heap.addString(it.second, unescape(it.third.substring(1, it.third.length-1), Position("<stackvmsource>", 0, 0, 0)))
-                    DataType.ARRAY_UB, DataType.ARRAY_B,
-                    DataType.ARRAY_UW, DataType.ARRAY_W -> {
-                        val numbers = it.third.substring(1, it.third.length-1).split(',')
-                        val intarray = numbers.map{number->
-                            val num=number.trim()
-                            if(num.startsWith("&")) {
-                                // it's AddressOf
-                                val scopedname = num.substring(1)
-                                val iref = IdentifierReference(scopedname.split('.'), Position("<intermediate>", 0,0,0))
-                                val addrOf = AddressOf(iref, Position("<intermediate>", 0,0,0))
-                                addrOf.scopedname=scopedname
-                                IntegerOrAddressOf(null, addrOf)
-                            } else {
-                                IntegerOrAddressOf(num.toInt(), null)
-                            }
-                        }.toTypedArray()
-                        heap.addIntegerArray(it.second, intarray)
-                    }
-                    DataType.ARRAY_F -> {
-                        val numbers = it.third.substring(1, it.third.length-1).split(',')
-                        val doublearray = numbers.map{number->number.trim().toDouble()}.toDoubleArray()
-                        heap.addDoublesArray(doublearray)
-                    }
-                    in NumericDatatypes -> throw VmExecutionException("invalid heap value type ${it.second}")
-                    else -> throw VmExecutionException("weird datatype")
-                }
-            }
-        }
-
-        private fun loadInstructions(lines: Iterator<IndexedValue<String>>, heap: HeapValues): Pair<MutableList<Instruction>, Map<String, Instruction>> {
-            val instructions = mutableListOf<Instruction>()
-            val labels = mutableMapOf<String, Instruction>()
-            val splitpattern = Pattern.compile("\\s+")
-            val nextInstructionLabels = Stack<String>()     // more than one label can occur on the isSameAs line
-
-            while(true) {
-                val (lineNr, line) = lines.next()
-                if(line.isEmpty())
-                    continue
-                if(line=="%end_instructions")
-                    return Pair(instructions, labels)
-                if(!line.startsWith(' ') && line.endsWith(':')) {
-                    nextInstructionLabels.push(line.substring(0, line.length-1))
-                } else if(line.startsWith(' ')) {
-                    val parts = line.trimStart().split(splitpattern, limit = 2)
-                    val opcodeStr = parts[0].toUpperCase()
-                    val opcode= Opcode.valueOf(if(opcodeStr.startsWith('_')) opcodeStr.substring(1) else opcodeStr)
-                    val args = if(parts.size==2) parts[1] else null
-                    val instruction = when(opcode) {
-                        Opcode.LINE -> Instruction(opcode, null, callLabel = args)
-                        Opcode.JUMP, Opcode.CALL, Opcode.BNEG, Opcode.BPOS,
-                        Opcode.BZ, Opcode.BNZ, Opcode.BCS, Opcode.BCC,
-                        Opcode.JZ, Opcode.JNZ, Opcode.JZW, Opcode.JNZW -> {
-                            if(args!!.startsWith('$')) {
-                                Instruction(opcode, RuntimeValue(DataType.UWORD, args.substring(1).toInt(16)))
-                            } else {
-                                Instruction(opcode, callLabel = args)
-                            }
-                        }
-                        in opcodesWithVarArgument -> {
-                            val withoutQuotes =
-                                    if(args!!.startsWith('"') && args.endsWith('"'))
-                                        args.substring(1, args.length-1) else args
-
-                            Instruction(opcode, callLabel = withoutQuotes)
-                        }
-                        Opcode.SYSCALL -> {
-                            if(args!! in syscallNames) {
-                                val call = Syscall.valueOf(args)
-                                Instruction(opcode, RuntimeValue(DataType.UBYTE, call.callNr))
-                            } else {
-                                val args2 = args.replace('.', '_')
-                                if(args2 in syscallNames) {
-                                    val call = Syscall.valueOf(args2)
-                                    Instruction(opcode, RuntimeValue(DataType.UBYTE, call.callNr))
-                                } else {
-                                    // the syscall is not yet implemented. emit a stub.
-                                    Instruction(Opcode.SYSCALL, RuntimeValue(DataType.UBYTE, Syscall.SYSCALLSTUB.callNr), callLabel = args2)
-                                }
-                            }
-                        }
-                        Opcode.INCLUDE_FILE -> {
-                            val argparts = args!!.split(' ')
-                            val filename = argparts[0]
-                            val offset = if(argparts.size>=2 && argparts[1]!="null") getArgValue(argparts[1], heap) else null
-                            val length = if(argparts.size>=3 && argparts[2]!="null") getArgValue(argparts[2], heap) else null
-                            Instruction(opcode, offset, length, filename)
-                        }
-                        else -> {
-                            Instruction(opcode, getArgValue(args, heap))
-                        }
-                    }
-                    instructions.add(instruction)
-                    while(nextInstructionLabels.isNotEmpty()) {
-                        val label = nextInstructionLabels.pop()
-                        labels[label] = instruction
-                    }
-                } else throw VmExecutionException("syntax error at line ${lineNr + 1}")
-            }
-        }
-
-        private fun getArgValue(args: String?, heap: HeapValues): RuntimeValue? {
-            if(args==null)
-                return null
-            if(args[0]=='"' && args[args.length-1]=='"') {
-                throw VmExecutionException("encountered a string arg value, but all strings should already have been moved into the heap")
-            }
-            val (type, valueStr) = args.split(':')
-            return when(type) {
-                "b" -> RuntimeValue(DataType.BYTE, valueStr.toShort(16))
-                "ub" -> RuntimeValue(DataType.UBYTE, valueStr.toShort(16))
-                "w" -> RuntimeValue(DataType.WORD, valueStr.toInt(16))
-                "uw" -> RuntimeValue(DataType.UWORD, valueStr.toInt(16))
-                "f" -> RuntimeValue(DataType.FLOAT, valueStr.toDouble())
-                "heap" -> {
-                    val heapId = valueStr.toInt()
-                    RuntimeValue(heap.get(heapId).type, heapId = heapId)
-                }
-                else -> throw VmExecutionException("invalid datatype $type")
-            }
-        }
-
-        private fun loadVars(lines: Iterator<IndexedValue<String>>,
-                             vars: MutableMap<String, RuntimeValue>) {
-            val splitpattern = Pattern.compile("\\s+")
-            while(true) {
-                val (_, line) = lines.next()
-                if(line=="%end_variables")
-                    return
-                val (name, typeStr, valueStr) = line.split(splitpattern, limit = 3)
-                if(valueStr[0] !='"' && ':' !in valueStr)
-                    throw VmExecutionException("missing value type character")
-                val value = when(val type = DataType.valueOf(typeStr.toUpperCase())) {
-                    DataType.UBYTE -> RuntimeValue(DataType.UBYTE, valueStr.substring(3).toShort(16))
-                    DataType.BYTE -> RuntimeValue(DataType.BYTE, valueStr.substring(2).toShort(16))
-                    DataType.UWORD -> RuntimeValue(DataType.UWORD, valueStr.substring(3).toInt(16))
-                    DataType.WORD -> RuntimeValue(DataType.WORD, valueStr.substring(2).toInt(16))
-                    DataType.FLOAT -> RuntimeValue(DataType.FLOAT, valueStr.substring(2).toDouble())
-                    in StringDatatypes -> {
-                        if(valueStr.startsWith('"') && valueStr.endsWith('"'))
-                            throw VmExecutionException("encountered a var with a string value, but all string values should already have been moved into the heap")
-                        else if(!valueStr.startsWith("heap:"))
-                            throw VmExecutionException("invalid string value, should be a heap reference")
-                        else {
-                            val heapId = valueStr.substring(5).toInt()
-                            RuntimeValue(type, heapId = heapId)
-                        }
-                    }
-                    in ArrayDatatypes -> {
-                        if(!valueStr.startsWith("heap:"))
-                            throw VmExecutionException("invalid array value, should be a heap reference")
-                        else {
-                            val heapId = valueStr.substring(5).toInt()
-                            RuntimeValue(type, heapId = heapId)
-                        }
-                    }
-                    else -> throw VmExecutionException("weird datatype")
-                }
-                vars[name] = value
-            }
-        }
-
-        private fun loadMemoryPointers(lines: Iterator<IndexedValue<String>>,
-                                       pointers: MutableMap<String, Pair<Int, DataType>>,
-                                       heap: HeapValues) {
-            val splitpattern = Pattern.compile("\\s+")
-            while(true) {
-                val (_, line) = lines.next()
-                if(line=="%end_memorypointers")
-                    return
-                val (name, typeStr, valueStr) = line.split(splitpattern, limit = 3)
-                if(valueStr[0] !='"' && ':' !in valueStr)
-                    throw VmExecutionException("missing value type character")
-                val type = DataType.valueOf(typeStr.toUpperCase())
-                val value = getArgValue(valueStr, heap)!!.integerValue()
-                pointers[name] = Pair(value, type)
-            }
-        }
-
-        private fun loadMemory(lines: Iterator<IndexedValue<String>>, memory: MutableMap<Int, List<RuntimeValue>>): Map<Int, List<RuntimeValue>> {
-            while(true) {
-                val (lineNr, line) = lines.next()
-                if(line=="%end_memory")
-                    return memory
-                val address = line.substringBefore(' ').toInt(16)
-                val rest = line.substringAfter(' ').trim()
-                if(rest.startsWith('"')) {
-                    TODO("memory init with char/string")
-                } else {
-                    val valueStrings = rest.split(' ')
-                    val values = mutableListOf<RuntimeValue>()
-                    valueStrings.forEach {
-                        when(it.length) {
-                            2 -> values.add(RuntimeValue(DataType.UBYTE, it.toShort(16)))
-                            4 -> values.add(RuntimeValue(DataType.UWORD, it.toInt(16)))
-                            else -> throw VmExecutionException("invalid value at line $lineNr+1")
-                        }
-                    }
-                    memory[address] = values
-                }
-            }
-        }
-    }
-}

compiler/src/prog8/stackvm/ScreenDialog.kt

@@ -1,188 +0,0 @@
-package prog8.stackvm
-
-import prog8.compiler.target.c64.Charset
-import prog8.compiler.target.c64.Colors
-import prog8.compiler.target.c64.Petscii
-import java.awt.*
-import java.awt.event.KeyEvent
-import java.awt.event.KeyListener
-import java.awt.image.BufferedImage
-import javax.swing.JFrame
-import javax.swing.JPanel
-import javax.swing.Timer
-
-
-class BitmapScreenPanel : KeyListener, JPanel() {
-
-    private val image = BufferedImage(SCREENWIDTH, SCREENHEIGHT, BufferedImage.TYPE_INT_ARGB)
-    private val g2d = image.graphics as Graphics2D
-    private var cursorX: Int=0
-    private var cursorY: Int=0
-
-    init {
-        val size = Dimension(image.width * SCALING, image.height * SCALING)
-        minimumSize = size
-        maximumSize = size
-        preferredSize = size
-        clearScreen(6)
-        isFocusable = true
-        requestFocusInWindow()
-        addKeyListener(this)
-    }
-
-    override fun keyTyped(p0: KeyEvent?) {}
-
-    override fun keyPressed(p0: KeyEvent?) {
-        println("pressed: $p0.k")
-    }
-
-    override fun keyReleased(p0: KeyEvent?) {
-        println("released: $p0")
-    }
-
-    override fun paint(graphics: Graphics?) {
-        val g2d = graphics as Graphics2D?
-        g2d!!.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_OFF)
-        g2d.setRenderingHint(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_DISABLE)
-        g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR)
-        g2d.drawImage(image, 0, 0, image.width * 3, image.height * 3, null)
-    }
-
-    fun clearScreen(color: Short) {
-        g2d.background = Colors.palette[color % Colors.palette.size]
-        g2d.clearRect(0, 0, SCREENWIDTH, SCREENHEIGHT)
-        cursorX = 0
-        cursorY = 0
-    }
-    fun setPixel(x: Int, y: Int, color: Short) {
-        image.setRGB(x, y, Colors.palette[color % Colors.palette.size].rgb)
-    }
-    fun drawLine(x1: Int, y1: Int, x2: Int, y2: Int, color: Short) {
-        g2d.color = Colors.palette[color % Colors.palette.size]
-        g2d.drawLine(x1, y1, x2, y2)
-    }
-    fun printText(text: String, color: Short, lowercase: Boolean) {
-        val lines = text.split('\n')
-        for(line in lines.withIndex()) {
-            printTextSingleLine(line.value, color, lowercase)
-            if(line.index<lines.size-1) {
-                cursorX=0
-                cursorY++
-            }
-        }
-    }
-    private fun printTextSingleLine(text: String, color: Short, lowercase: Boolean) {
-        for(clearx in cursorX until cursorX+text.length) {
-            g2d.clearRect(8*clearx, 8*y, 8, 8)
-        }
-        for(sc in Petscii.encodeScreencode(text, lowercase)) {
-            setChar(cursorX, cursorY, sc, color)
-            cursorX++
-            if(cursorX>=(SCREENWIDTH/8)) {
-                cursorY++
-                cursorX=0
-            }
-        }
-    }
-
-    fun printChar(char: Short) {
-        if(char==13.toShort() || char==141.toShort()) {
-            cursorX=0
-            cursorY++
-        } else {
-            setChar(cursorX, cursorY, char, 1)
-            cursorX++
-            if (cursorX >= (SCREENWIDTH / 8)) {
-                cursorY++
-                cursorX = 0
-            }
-        }
-    }
-
-    fun setChar(x: Int, y: Int, screenCode: Short, color: Short) {
-        g2d.clearRect(8*x, 8*y, 8, 8)
-        val colorIdx = (color % Colors.palette.size).toShort()
-        val coloredImage = Charset.getColoredChar(screenCode, colorIdx)
-        g2d.drawImage(coloredImage, 8*x, 8*y , null)
-    }
-
-    fun setCursorPos(x: Int, y: Int) {
-        cursorX = x
-        cursorY = y
-    }
-
-    fun getCursorPos(): Pair<Int, Int> {
-        return Pair(cursorX, cursorY)
-    }
-
-    fun writeText(x: Int, y: Int, text: String, color: Short, lowercase: Boolean) {
-        var xx=x
-        for(clearx in xx until xx+text.length) {
-            g2d.clearRect(8*clearx, 8*y, 8, 8)
-        }
-        for(sc in Petscii.encodeScreencode(text, lowercase)) {
-            setChar(xx++, y, sc, color)
-        }
-    }
-
-
-    companion object {
-        const val SCREENWIDTH = 320
-        const val SCREENHEIGHT = 200
-        const val SCALING = 3
-    }
-}
-
-
-class ScreenDialog : JFrame() {
-    val canvas = BitmapScreenPanel()
-
-    init {
-        val borderWidth = 16
-        title = "StackVm graphics. Text I/O goes to console."
-        layout = GridBagLayout()
-        defaultCloseOperation = JFrame.EXIT_ON_CLOSE
-        isResizable = false
-
-        // the borders (top, left, right, bottom)
-        val borderTop = JPanel().apply {
-            preferredSize = Dimension(BitmapScreenPanel.SCALING * (BitmapScreenPanel.SCREENWIDTH+2*borderWidth), BitmapScreenPanel.SCALING * borderWidth)
-            background = Colors.palette[14]
-        }
-        val borderBottom = JPanel().apply {
-            preferredSize =Dimension(BitmapScreenPanel.SCALING * (BitmapScreenPanel.SCREENWIDTH+2*borderWidth), BitmapScreenPanel.SCALING * borderWidth)
-            background = Colors.palette[14]
-        }
-        val borderLeft = JPanel().apply {
-            preferredSize =Dimension(BitmapScreenPanel.SCALING * borderWidth, BitmapScreenPanel.SCALING * BitmapScreenPanel.SCREENHEIGHT)
-            background = Colors.palette[14]
-        }
-        val borderRight = JPanel().apply {
-            preferredSize =Dimension(BitmapScreenPanel.SCALING * borderWidth, BitmapScreenPanel.SCALING * BitmapScreenPanel.SCREENHEIGHT)
-            background = Colors.palette[14]
-        }
-        var c = GridBagConstraints()
-        c.gridx=0; c.gridy=1; c.gridwidth=3
-        add(borderTop, c)
-        c = GridBagConstraints()
-        c.gridx=0; c.gridy=2
-        add(borderLeft, c)
-        c = GridBagConstraints()
-        c.gridx=2; c.gridy=2
-        add(borderRight, c)
-        c = GridBagConstraints()
-        c.gridx=0; c.gridy=3; c.gridwidth=3
-        add(borderBottom, c)
-        // the screen canvas(bitmap)
-        c = GridBagConstraints()
-        c.gridx = 1; c.gridy = 2
-        add(canvas, c)
-
-        canvas.requestFocusInWindow()
-    }
-
-    fun start() {
-        val repaintTimer = Timer(1000 / 60) { repaint() }
-        repaintTimer.start()
-    }
-}

compiler/src/prog8/vm/RuntimeValue.kt

@@ -0,0 +1,658 @@
+package prog8.vm
+
+import prog8.ast.base.ByteDatatypes
+import prog8.ast.base.DataType
+import prog8.ast.base.WordDatatypes
+import prog8.ast.expressions.ArrayLiteralValue
+import prog8.ast.expressions.NumericLiteralValue
+import prog8.ast.expressions.StringLiteralValue
+import prog8.vm.astvm.VmExecutionException
+import java.util.Objects
+import kotlin.math.abs
+import kotlin.math.pow
+
+
+/**
+ * Rather than a literal value (NumericLiteralValue) that occurs in the parsed source code,
+ * this runtime value can be used to *execute* the parsed Ast (or another intermediary form)
+ * It contains a value of a variable during run time of the program and provides arithmetic operations on the value.
+ */
+
+abstract class RuntimeValueBase(val type: DataType) {
+    abstract fun numericValue(): Number
+    abstract fun integerValue(): Int
+}
+
+
+class RuntimeValueNumeric(type: DataType, num: Number): RuntimeValueBase(type) {
+
+    val byteval: Short?
+    val wordval: Int?
+    val floatval: Double?
+    val asBoolean: Boolean
+
+    companion object {
+        fun fromLv(literalValue: NumericLiteralValue): RuntimeValueNumeric {
+            return RuntimeValueNumeric(literalValue.type, num = literalValue.number)
+        }
+    }
+
+    init {
+        when (type) {
+            DataType.UBYTE -> {
+                val inum = num.toInt()
+                require(inum in 0..255) { "invalid value for ubyte: $inum" }
+                byteval = inum.toShort()
+                wordval = null
+                floatval = null
+                asBoolean = byteval != 0.toShort()
+            }
+            DataType.BYTE -> {
+                val inum = num.toInt()
+                require(inum in -128..127) { "invalid value for byte: $inum" }
+                byteval = inum.toShort()
+                wordval = null
+                floatval = null
+                asBoolean = byteval != 0.toShort()
+            }
+            DataType.UWORD -> {
+                val inum = num.toInt()
+                require(inum in 0..65535) { "invalid value for uword: $inum" }
+                wordval = inum
+                byteval = null
+                floatval = null
+                asBoolean = wordval != 0
+            }
+            DataType.WORD -> {
+                val inum = num.toInt()
+                require(inum in -32768..32767) { "invalid value for word: $inum" }
+                wordval = inum
+                byteval = null
+                floatval = null
+                asBoolean = wordval != 0
+            }
+            DataType.FLOAT -> {
+                floatval = num.toDouble()
+                byteval = null
+                wordval = null
+                asBoolean = floatval != 0.0
+            }
+            else -> throw VmExecutionException("not a numeric value")
+        }
+    }
+
+    override fun toString(): String {
+        return when (type) {
+            DataType.UBYTE -> "ub:%02x".format(byteval)
+            DataType.BYTE -> {
+                if (byteval!! < 0)
+                    "b:-%02x".format(abs(byteval.toInt()))
+                else
+                    "b:%02x".format(byteval)
+            }
+            DataType.UWORD -> "uw:%04x".format(wordval)
+            DataType.WORD -> {
+                if (wordval!! < 0)
+                    "w:-%04x".format(abs(wordval))
+                else
+                    "w:%04x".format(wordval)
+            }
+            DataType.FLOAT -> "f:$floatval"
+            else -> "???"
+        }
+    }
+
+    override fun numericValue(): Number {
+        return when (type) {
+            in ByteDatatypes -> byteval!!
+            in WordDatatypes -> wordval!!
+            DataType.FLOAT -> floatval!!
+            else -> throw ArithmeticException("invalid datatype for numeric value: $type")
+        }
+    }
+
+    override fun integerValue(): Int {
+        return when (type) {
+            in ByteDatatypes -> byteval!!.toInt()
+            in WordDatatypes -> wordval!!
+            DataType.FLOAT -> throw ArithmeticException("float to integer loss of precision")
+            else -> throw ArithmeticException("invalid datatype for integer value: $type")
+        }
+    }
+
+    override fun hashCode(): Int = Objects.hash(byteval, wordval, floatval, type)
+
+    override fun equals(other: Any?): Boolean {
+        if (other == null || other !is RuntimeValueNumeric)
+            return false
+        return compareTo(other) == 0      // note: datatype doesn't matter
+    }
+
+    operator fun compareTo(other: RuntimeValueNumeric): Int = numericValue().toDouble().compareTo(other.numericValue().toDouble())
+
+    private fun arithResult(leftDt: DataType, result: Number, rightDt: DataType, op: String): RuntimeValueNumeric {
+        if (leftDt != rightDt)
+            throw ArithmeticException("left and right datatypes are not the same")
+        if (result.toDouble() < 0) {
+            return when (leftDt) {
+                DataType.UBYTE, DataType.UWORD -> {
+                    // storing a negative number in an unsigned one is done by storing the 2's complement instead
+                    val number = abs(result.toDouble().toInt())
+                    if (leftDt == DataType.UBYTE)
+                        RuntimeValueNumeric(DataType.UBYTE, (number xor 255) + 1)
+                    else
+                        RuntimeValueNumeric(DataType.UWORD, (number xor 65535) + 1)
+                }
+                DataType.BYTE -> {
+                    val v = result.toInt() and 255
+                    if (v < 128)
+                        RuntimeValueNumeric(DataType.BYTE, v)
+                    else
+                        RuntimeValueNumeric(DataType.BYTE, v - 256)
+                }
+                DataType.WORD -> {
+                    val v = result.toInt() and 65535
+                    if (v < 32768)
+                        RuntimeValueNumeric(DataType.WORD, v)
+                    else
+                        RuntimeValueNumeric(DataType.WORD, v - 65536)
+                }
+                DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, result)
+                else -> throw ArithmeticException("$op on non-numeric type")
+            }
+        }
+
+        return when (leftDt) {
+            DataType.UBYTE -> RuntimeValueNumeric(DataType.UBYTE, result.toInt() and 255)
+            DataType.BYTE -> {
+                val v = result.toInt() and 255
+                if (v < 128)
+                    RuntimeValueNumeric(DataType.BYTE, v)
+                else
+                    RuntimeValueNumeric(DataType.BYTE, v - 256)
+            }
+            DataType.UWORD -> RuntimeValueNumeric(DataType.UWORD, result.toInt() and 65535)
+            DataType.WORD -> {
+                val v = result.toInt() and 65535
+                if (v < 32768)
+                    RuntimeValueNumeric(DataType.WORD, v)
+                else
+                    RuntimeValueNumeric(DataType.WORD, v - 65536)
+            }
+            DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, result)
+            else -> throw ArithmeticException("$op on non-numeric type")
+        }
+    }
+
+    fun add(other: RuntimeValueNumeric): RuntimeValueNumeric {
+        if (other.type == DataType.FLOAT && (type != DataType.FLOAT))
+            throw ArithmeticException("floating point loss of precision on type $type")
+        val v1 = numericValue()
+        val v2 = other.numericValue()
+        val result = v1.toDouble() + v2.toDouble()
+        return arithResult(type, result, other.type, "add")
+    }
+
+    fun sub(other: RuntimeValueNumeric): RuntimeValueNumeric {
+        if (other.type == DataType.FLOAT && (type != DataType.FLOAT))
+            throw ArithmeticException("floating point loss of precision on type $type")
+        val v1 = numericValue()
+        val v2 = other.numericValue()
+        val result = v1.toDouble() - v2.toDouble()
+        return arithResult(type, result, other.type, "sub")
+    }
+
+    fun mul(other: RuntimeValueNumeric): RuntimeValueNumeric {
+        if (other.type == DataType.FLOAT && (type != DataType.FLOAT))
+            throw ArithmeticException("floating point loss of precision on type $type")
+        val v1 = numericValue()
+        val v2 = other.numericValue()
+        val result = v1.toDouble() * v2.toDouble()
+        return arithResult(type, result, other.type, "mul")
+    }
+
+    fun div(other: RuntimeValueNumeric): RuntimeValueNumeric {
+        if (other.type == DataType.FLOAT && (type != DataType.FLOAT))
+            throw ArithmeticException("floating point loss of precision on type $type")
+        val v1 = numericValue()
+        val v2 = other.numericValue()
+        if (v2.toDouble() == 0.0) {
+            when (type) {
+                DataType.UBYTE -> return RuntimeValueNumeric(DataType.UBYTE, 255)
+                DataType.BYTE -> return RuntimeValueNumeric(DataType.BYTE, 127)
+                DataType.UWORD -> return RuntimeValueNumeric(DataType.UWORD, 65535)
+                DataType.WORD -> return RuntimeValueNumeric(DataType.WORD, 32767)
+                else -> {
+                }
+            }
+        }
+        val result = v1.toDouble() / v2.toDouble()
+        // NOTE: integer division returns integer result!
+        return when (type) {
+            DataType.UBYTE -> RuntimeValueNumeric(DataType.UBYTE, result)
+            DataType.BYTE -> RuntimeValueNumeric(DataType.BYTE, result)
+            DataType.UWORD -> RuntimeValueNumeric(DataType.UWORD, result)
+            DataType.WORD -> RuntimeValueNumeric(DataType.WORD, result)
+            DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, result)
+            else -> throw ArithmeticException("div on non-numeric type")
+        }
+    }
+
+    fun remainder(other: RuntimeValueNumeric): RuntimeValueNumeric {
+        val v1 = numericValue()
+        val v2 = other.numericValue()
+        val result = v1.toDouble() % v2.toDouble()
+        return arithResult(type, result, other.type, "remainder")
+    }
+
+    fun pow(other: RuntimeValueNumeric): RuntimeValueNumeric {
+        val v1 = numericValue()
+        val v2 = other.numericValue()
+        val result = v1.toDouble().pow(v2.toDouble())
+        return arithResult(type, result, other.type, "pow")
+    }
+
+    fun shl(): RuntimeValueNumeric {
+        val v = integerValue()
+        return when (type) {
+            DataType.UBYTE -> RuntimeValueNumeric(type, (v shl 1) and 255)
+            DataType.UWORD -> RuntimeValueNumeric(type, (v shl 1) and 65535)
+            DataType.BYTE -> {
+                val value = v shl 1
+                if (value < 128)
+                    RuntimeValueNumeric(type, value)
+                else
+                    RuntimeValueNumeric(type, value - 256)
+            }
+            DataType.WORD -> {
+                val value = v shl 1
+                if (value < 32768)
+                    RuntimeValueNumeric(type, value)
+                else
+                    RuntimeValueNumeric(type, value - 65536)
+            }
+            else -> throw ArithmeticException("invalid type for shl: $type")
+        }
+    }
+
+    fun shr(): RuntimeValueNumeric {
+        val v = integerValue()
+        return when (type) {
+            DataType.UBYTE -> RuntimeValueNumeric(type, v ushr 1)
+            DataType.BYTE -> RuntimeValueNumeric(type, v shr 1)
+            DataType.UWORD -> RuntimeValueNumeric(type, v ushr 1)
+            DataType.WORD -> RuntimeValueNumeric(type, v shr 1)
+            else -> throw ArithmeticException("invalid type for shr: $type")
+        }
+    }
+
+    fun rol(carry: Boolean): Pair<RuntimeValueNumeric, Boolean> {
+        // 9 or 17 bit rotate left (with carry))
+        return when (type) {
+            DataType.UBYTE, DataType.BYTE -> {
+                val v = byteval!!.toInt()
+                val newCarry = (v and 0x80) != 0
+                val newval = (v and 0x7f shl 1) or (if (carry) 1 else 0)
+                Pair(RuntimeValueNumeric(DataType.UBYTE, newval), newCarry)
+            }
+            DataType.UWORD, DataType.WORD -> {
+                val v = wordval!!
+                val newCarry = (v and 0x8000) != 0
+                val newval = (v and 0x7fff shl 1) or (if (carry) 1 else 0)
+                Pair(RuntimeValueNumeric(DataType.UWORD, newval), newCarry)
+            }
+            else -> throw ArithmeticException("rol can only work on byte/word")
+        }
+    }
+
+    fun ror(carry: Boolean): Pair<RuntimeValueNumeric, Boolean> {
+        // 9 or 17 bit rotate right (with carry)
+        return when (type) {
+            DataType.UBYTE, DataType.BYTE -> {
+                val v = byteval!!.toInt()
+                val newCarry = v and 1 != 0
+                val newval = (v ushr 1) or (if (carry) 0x80 else 0)
+                Pair(RuntimeValueNumeric(DataType.UBYTE, newval), newCarry)
+            }
+            DataType.UWORD, DataType.WORD -> {
+                val v = wordval!!
+                val newCarry = v and 1 != 0
+                val newval = (v ushr 1) or (if (carry) 0x8000 else 0)
+                Pair(RuntimeValueNumeric(DataType.UWORD, newval), newCarry)
+            }
+            else -> throw ArithmeticException("ror2 can only work on byte/word")
+        }
+    }
+
+    fun rol2(): RuntimeValueNumeric {
+        // 8 or 16 bit rotate left
+        return when (type) {
+            DataType.UBYTE, DataType.BYTE -> {
+                val v = byteval!!.toInt()
+                val carry = (v and 0x80) ushr 7
+                val newval = (v and 0x7f shl 1) or carry
+                RuntimeValueNumeric(DataType.UBYTE, newval)
+            }
+            DataType.UWORD, DataType.WORD -> {
+                val v = wordval!!
+                val carry = (v and 0x8000) ushr 15
+                val newval = (v and 0x7fff shl 1) or carry
+                RuntimeValueNumeric(DataType.UWORD, newval)
+            }
+            else -> throw ArithmeticException("rol2 can only work on byte/word")
+        }
+    }
+
+    fun ror2(): RuntimeValueNumeric {
+        // 8 or 16 bit rotate right
+        return when (type) {
+            DataType.UBYTE, DataType.BYTE -> {
+                val v = byteval!!.toInt()
+                val carry = v and 1 shl 7
+                val newval = (v ushr 1) or carry
+                RuntimeValueNumeric(DataType.UBYTE, newval)
+            }
+            DataType.UWORD, DataType.WORD -> {
+                val v = wordval!!
+                val carry = v and 1 shl 15
+                val newval = (v ushr 1) or carry
+                RuntimeValueNumeric(DataType.UWORD, newval)
+            }
+            else -> throw ArithmeticException("ror2 can only work on byte/word")
+        }
+    }
+
+    fun neg(): RuntimeValueNumeric {
+        return when (type) {
+            DataType.BYTE -> RuntimeValueNumeric(DataType.BYTE, -(byteval!!))
+            DataType.WORD -> RuntimeValueNumeric(DataType.WORD, -(wordval!!))
+            DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, -(floatval)!!)
+            else -> throw ArithmeticException("neg can only work on byte/word/float")
+        }
+    }
+
+    fun abs(): RuntimeValueNumeric {
+        return when (type) {
+            DataType.BYTE -> RuntimeValueNumeric(DataType.BYTE, abs(byteval!!.toInt()))
+            DataType.WORD -> RuntimeValueNumeric(DataType.WORD, abs(wordval!!))
+            DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, abs(floatval!!))
+            else -> throw ArithmeticException("abs can only work on byte/word/float")
+        }
+    }
+
+    fun bitand(other: RuntimeValueNumeric): RuntimeValueNumeric {
+        val v1 = integerValue()
+        val v2 = other.integerValue()
+        val result = v1 and v2
+        return RuntimeValueNumeric(type, result)
+    }
+
+    fun bitor(other: RuntimeValueNumeric): RuntimeValueNumeric {
+        val v1 = integerValue()
+        val v2 = other.integerValue()
+        val result = v1 or v2
+        return RuntimeValueNumeric(type, result)
+    }
+
+    fun bitxor(other: RuntimeValueNumeric): RuntimeValueNumeric {
+        val v1 = integerValue()
+        val v2 = other.integerValue()
+        val result = v1 xor v2
+        return RuntimeValueNumeric(type, result)
+    }
+
+    fun and(other: RuntimeValueNumeric) = RuntimeValueNumeric(DataType.UBYTE, if (this.asBoolean && other.asBoolean) 1 else 0)
+    fun or(other: RuntimeValueNumeric) = RuntimeValueNumeric(DataType.UBYTE, if (this.asBoolean || other.asBoolean) 1 else 0)
+    fun xor(other: RuntimeValueNumeric) = RuntimeValueNumeric(DataType.UBYTE, if (this.asBoolean xor other.asBoolean) 1 else 0)
+    fun not() = RuntimeValueNumeric(DataType.UBYTE, if (this.asBoolean) 0 else 1)
+
+    fun inv(): RuntimeValueNumeric {
+        return when (type) {
+            DataType.UBYTE -> RuntimeValueNumeric(type, byteval!!.toInt().inv() and 255)
+            DataType.UWORD -> RuntimeValueNumeric(type, wordval!!.inv() and 65535)
+            DataType.BYTE -> RuntimeValueNumeric(type, byteval!!.toInt().inv())
+            DataType.WORD -> RuntimeValueNumeric(type, wordval!!.inv())
+            else -> throw ArithmeticException("inv can only work on byte/word")
+        }
+    }
+
+    fun inc(): RuntimeValueNumeric {
+        return when (type) {
+            DataType.UBYTE -> RuntimeValueNumeric(type, (byteval!! + 1) and 255)
+            DataType.UWORD -> RuntimeValueNumeric(type, (wordval!! + 1) and 65535)
+            DataType.BYTE -> {
+                val newval = byteval!! + 1
+                if (newval == 128)
+                    RuntimeValueNumeric(type, -128)
+                else
+                    RuntimeValueNumeric(type, newval)
+            }
+            DataType.WORD -> {
+                val newval = wordval!! + 1
+                if (newval == 32768)
+                    RuntimeValueNumeric(type, -32768)
+                else
+                    RuntimeValueNumeric(type, newval)
+            }
+            DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, floatval!! + 1)
+            else -> throw ArithmeticException("inc can only work on numeric types")
+        }
+    }
+
+    fun dec(): RuntimeValueNumeric {
+        return when (type) {
+            DataType.UBYTE -> RuntimeValueNumeric(type, (byteval!! - 1) and 255)
+            DataType.UWORD -> RuntimeValueNumeric(type, (wordval!! - 1) and 65535)
+            DataType.BYTE -> {
+                val newval = byteval!! - 1
+                if (newval == -129)
+                    RuntimeValueNumeric(type, 127)
+                else
+                    RuntimeValueNumeric(type, newval)
+            }
+            DataType.WORD -> {
+                val newval = wordval!! - 1
+                if (newval == -32769)
+                    RuntimeValueNumeric(type, 32767)
+                else
+                    RuntimeValueNumeric(type, newval)
+            }
+            DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, floatval!! - 1)
+            else -> throw ArithmeticException("dec can only work on numeric types")
+        }
+    }
+
+    fun msb(): RuntimeValueNumeric {
+        return when (type) {
+            in ByteDatatypes -> RuntimeValueNumeric(DataType.UBYTE, 0)
+            in WordDatatypes -> RuntimeValueNumeric(DataType.UBYTE, wordval!! ushr 8 and 255)
+            else -> throw ArithmeticException("msb can only work on (u)byte/(u)word")
+        }
+    }
+
+    fun cast(targetType: DataType): RuntimeValueNumeric {
+        return when (type) {
+            DataType.UBYTE -> {
+                when (targetType) {
+                    DataType.UBYTE -> this
+                    DataType.BYTE -> {
+                        val nval = byteval!!.toInt()
+                        if (nval < 128)
+                            RuntimeValueNumeric(DataType.BYTE, nval)
+                        else
+                            RuntimeValueNumeric(DataType.BYTE, nval - 256)
+                    }
+                    DataType.UWORD -> RuntimeValueNumeric(DataType.UWORD, numericValue())
+                    DataType.WORD -> {
+                        val nval = numericValue().toInt()
+                        if (nval < 32768)
+                            RuntimeValueNumeric(DataType.WORD, nval)
+                        else
+                            RuntimeValueNumeric(DataType.WORD, nval - 65536)
+                    }
+                    DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, numericValue())
+                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
+                }
+            }
+            DataType.BYTE -> {
+                when (targetType) {
+                    DataType.BYTE -> this
+                    DataType.UBYTE -> RuntimeValueNumeric(DataType.UBYTE, integerValue() and 255)
+                    DataType.UWORD -> RuntimeValueNumeric(DataType.UWORD, integerValue() and 65535)
+                    DataType.WORD -> RuntimeValueNumeric(DataType.WORD, integerValue())
+                    DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, numericValue())
+                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
+                }
+            }
+            DataType.UWORD -> {
+                when (targetType) {
+                    DataType.BYTE -> {
+                        val v = integerValue()
+                        if (v < 128)
+                            RuntimeValueNumeric(DataType.BYTE, v)
+                        else
+                            RuntimeValueNumeric(DataType.BYTE, v - 256)
+                    }
+                    DataType.UBYTE -> RuntimeValueNumeric(DataType.UBYTE, integerValue() and 255)
+                    DataType.UWORD -> this
+                    DataType.WORD -> {
+                        val v = integerValue()
+                        if (v < 32768)
+                            RuntimeValueNumeric(DataType.WORD, v)
+                        else
+                            RuntimeValueNumeric(DataType.WORD, v - 65536)
+                    }
+                    DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, numericValue())
+                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
+                }
+            }
+            DataType.WORD -> {
+                when (targetType) {
+                    DataType.BYTE -> {
+                        val v = integerValue() and 255
+                        if (v < 128)
+                            RuntimeValueNumeric(DataType.BYTE, v)
+                        else
+                            RuntimeValueNumeric(DataType.BYTE, v - 256)
+                    }
+                    DataType.UBYTE -> RuntimeValueNumeric(DataType.UBYTE, integerValue() and 65535)
+                    DataType.UWORD -> RuntimeValueNumeric(DataType.UWORD, integerValue())
+                    DataType.WORD -> this
+                    DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, numericValue())
+                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
+                }
+            }
+            DataType.FLOAT -> {
+                when (targetType) {
+                    DataType.BYTE -> {
+                        val integer = numericValue().toInt()
+                        if (integer in -128..127)
+                            RuntimeValueNumeric(DataType.BYTE, integer)
+                        else
+                            throw ArithmeticException("overflow when casting float to byte: $this")
+                    }
+                    DataType.UBYTE -> RuntimeValueNumeric(DataType.UBYTE, numericValue().toInt())
+                    DataType.UWORD -> RuntimeValueNumeric(DataType.UWORD, numericValue().toInt())
+                    DataType.WORD -> {
+                        val integer = numericValue().toInt()
+                        if (integer in -32768..32767)
+                            RuntimeValueNumeric(DataType.WORD, integer)
+                        else
+                            throw ArithmeticException("overflow when casting float to word: $this")
+                    }
+                    DataType.FLOAT -> this
+                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
+                }
+            }
+            else -> throw ArithmeticException("invalid type cast from $type to $targetType")
+        }
+    }
+}
+
+
+class RuntimeValueString(val str: String, val heapId: Int?): RuntimeValueBase(DataType.STR) {
+    companion object {
+        fun fromLv(string: StringLiteralValue): RuntimeValueString {
+            return RuntimeValueString(string.value, string.heapId)
+        }
+    }
+
+    override fun toString(): String = if(type==DataType.STR) "str:$str"  else "???"
+
+    override fun hashCode(): Int = Objects.hash(type, str)
+
+    override fun equals(other: Any?): Boolean {
+        if (other == null || other !is RuntimeValueString)
+            return false
+        return type == other.type && str == other.str
+    }
+
+    fun iterator(): Iterator<Number> = str.map { it.toShort() }.iterator()
+
+    override fun numericValue(): Number {
+        throw VmExecutionException("string is not a number")
+    }
+
+    override fun integerValue(): Int {
+        throw VmExecutionException("string is not a number")
+    }
+}
+
+
+open class RuntimeValueArray(type: DataType, val array: Array<Number>, val heapId: Int?): RuntimeValueBase(type) {
+
+    companion object {
+        fun fromLv(array: ArrayLiteralValue): RuntimeValueArray {
+            return if (array.type == DataType.ARRAY_F) {
+                val doubleArray = array.value.map { (it as NumericLiteralValue).number }.toTypedArray()
+                RuntimeValueArray(array.type, doubleArray, array.heapId)
+            } else {
+                val resultArray = mutableListOf<Number>()
+                for (elt in array.value.withIndex()) {
+                    if (elt.value is NumericLiteralValue)
+                        resultArray.add((elt.value as NumericLiteralValue).number.toInt())
+                    else {
+                        resultArray.add((elt.hashCode()))  // ...poor man's implementation of ADDRESSOF(array), it probably won't work very well
+                    }
+                }
+                RuntimeValueArray(array.type, resultArray.toTypedArray(), array.heapId)
+            }
+        }
+    }
+
+    override fun toString(): String {
+        return when (type) {
+            DataType.ARRAY_UB -> "array_ub:..."
+            DataType.ARRAY_B -> "array_b:..."
+            DataType.ARRAY_UW -> "array_uw:..."
+            DataType.ARRAY_W -> "array_w:..."
+            DataType.ARRAY_F -> "array_f:..."
+            else -> "???"
+        }
+    }
+
+    override fun hashCode(): Int = Objects.hash(type, array)
+
+    override fun equals(other: Any?): Boolean {
+        if (other == null || other !is RuntimeValueArray)
+            return false
+        return type == other.type && array.contentEquals(other.array)
+    }
+
+    open fun iterator(): Iterator<Number> = array.iterator()
+
+    override fun numericValue(): Number {
+        throw VmExecutionException("array is not a number")
+    }
+
+    override fun integerValue(): Int {
+        throw VmExecutionException("array is not a number")
+    }
+}
+
+
+class RuntimeValueRange(type: DataType, val range: IntProgression): RuntimeValueArray(type, range.toList().toTypedArray(), null) {
+    override fun iterator(): Iterator<Number> {
+        return range.iterator()
+    }
+}

compiler/src/prog8/vm/astvm/Expressions.kt

@@ -0,0 +1,177 @@
+package prog8.vm.astvm
+
+import prog8.ast.Program
+import prog8.ast.base.ArrayElementTypes
+import prog8.ast.base.DataType
+import prog8.ast.base.FatalAstException
+import prog8.ast.base.VarDeclType
+import prog8.ast.expressions.*
+import prog8.ast.statements.BuiltinFunctionStatementPlaceholder
+import prog8.ast.statements.Label
+import prog8.ast.statements.Subroutine
+import prog8.ast.statements.VarDecl
+import prog8.vm.*
+
+
+typealias BuiltinfunctionCaller =  (name: String, args: List<RuntimeValueNumeric>, flags: StatusFlags) -> RuntimeValueNumeric?
+typealias SubroutineCaller =  (sub: Subroutine, args: List<RuntimeValueNumeric>, startAtLabel: Label?) -> RuntimeValueNumeric?
+
+
+class EvalContext(val program: Program, val mem: Memory, val statusflags: StatusFlags,
+                  val runtimeVars: RuntimeVariables,
+                  val performBuiltinFunction: BuiltinfunctionCaller,
+                  val executeSubroutine: SubroutineCaller)
+
+fun evaluate(expr: Expression, ctx: EvalContext): RuntimeValueBase {
+    val constval = expr.constValue(ctx.program)
+    if(constval!=null)
+        return RuntimeValueNumeric.fromLv(constval)
+
+    when(expr) {
+        is NumericLiteralValue -> return RuntimeValueNumeric.fromLv(expr)
+        is StringLiteralValue -> return RuntimeValueString.fromLv(expr)
+        is ArrayLiteralValue -> return RuntimeValueArray.fromLv(expr)
+        is PrefixExpression -> {
+            return when(expr.operator) {
+                "-" -> (evaluate(expr.expression, ctx) as RuntimeValueNumeric).neg()
+                "~" -> (evaluate(expr.expression, ctx) as RuntimeValueNumeric).inv()
+                "not" -> (evaluate(expr.expression, ctx) as RuntimeValueNumeric).not()
+                // unary '+' should have been optimized away
+                else -> throw VmExecutionException("unsupported prefix operator "+expr.operator)
+            }
+        }
+        is BinaryExpression -> {
+            val left = evaluate(expr.left, ctx) as RuntimeValueNumeric
+            val right = evaluate(expr.right, ctx) as RuntimeValueNumeric
+            return when(expr.operator) {
+                "<" -> RuntimeValueNumeric(DataType.UBYTE, if (left < right) 1 else 0)
+                "<=" -> RuntimeValueNumeric(DataType.UBYTE, if (left <= right) 1 else 0)
+                ">" -> RuntimeValueNumeric(DataType.UBYTE, if (left > right) 1 else 0)
+                ">=" -> RuntimeValueNumeric(DataType.UBYTE, if (left >= right) 1 else 0)
+                "==" -> RuntimeValueNumeric(DataType.UBYTE, if (left == right) 1 else 0)
+                "!=" -> RuntimeValueNumeric(DataType.UBYTE, if (left != right) 1 else 0)
+                "+" -> left.add(right)
+                "-" -> left.sub(right)
+                "*" -> left.mul(right)
+                "/" -> left.div(right)
+                "**" -> left.pow(right)
+                "<<" -> {
+                    var result = left
+                    repeat(right.integerValue()) {result = result.shl()}
+                    result
+                }
+                ">>" -> {
+                    var result = left
+                    repeat(right.integerValue()) {result = result.shr()}
+                    result
+                }
+                "%" -> left.remainder(right)
+                "|" -> left.bitor(right)
+                "&" -> left.bitand(right)
+                "^" -> left.bitxor(right)
+                "and" -> left.and(right)
+                "or" -> left.or(right)
+                "xor" -> left.xor(right)
+                else -> throw VmExecutionException("unsupported operator "+expr.operator)
+            }
+        }
+        is ArrayIndexedExpression -> {
+            val array = evaluate(expr.identifier, ctx)
+            val index = evaluate(expr.arrayspec.index, ctx) as RuntimeValueNumeric
+            return when (array) {
+                is RuntimeValueString -> {
+                    val value = array.str[index.integerValue()]
+                    RuntimeValueNumeric(ArrayElementTypes.getValue(array.type), value.toShort())
+                }
+                is RuntimeValueArray -> {
+                    val value = array.array[index.integerValue()]
+                    RuntimeValueNumeric(ArrayElementTypes.getValue(array.type), value)
+                }
+                else -> throw VmExecutionException("weird type")
+            }
+        }
+        is TypecastExpression -> {
+            return (evaluate(expr.expression, ctx) as RuntimeValueNumeric).cast(expr.type)
+        }
+        is AddressOf -> {
+            // we support: address of heap var -> the heap id
+            return try {
+                val heapId = expr.identifier.heapId(ctx.program.namespace)
+                RuntimeValueNumeric(DataType.UWORD, heapId)
+            } catch( f: FatalAstException) {
+                // fallback: use the hash of the name, so we have at least *a* value...
+                val address = expr.identifier.hashCode() and 65535
+                RuntimeValueNumeric(DataType.UWORD, address)
+            }
+        }
+        is DirectMemoryRead -> {
+            val address = (evaluate(expr.addressExpression, ctx) as RuntimeValueNumeric).wordval!!
+            return RuntimeValueNumeric(DataType.UBYTE, ctx.mem.getUByte(address))
+        }
+        is RegisterExpr -> return ctx.runtimeVars.get(ctx.program.namespace, expr.register.name)
+        is IdentifierReference -> {
+            val scope = expr.definingScope()
+            val variable = scope.lookup(expr.nameInSource, expr)
+            if(variable is VarDecl) {
+                when {
+                    variable.type==VarDeclType.VAR -> return ctx.runtimeVars.get(variable.definingScope(), variable.name)
+                    variable.datatype==DataType.STRUCT -> throw VmExecutionException("cannot process structs by-value.  at ${expr.position}")
+                    else -> {
+                        val address = ctx.runtimeVars.getMemoryAddress(variable.definingScope(), variable.name)
+                        return when(variable.datatype) {
+                            DataType.UBYTE -> RuntimeValueNumeric(DataType.UBYTE, ctx.mem.getUByte(address))
+                            DataType.BYTE -> RuntimeValueNumeric(DataType.BYTE, ctx.mem.getSByte(address))
+                            DataType.UWORD -> RuntimeValueNumeric(DataType.UWORD, ctx.mem.getUWord(address))
+                            DataType.WORD -> RuntimeValueNumeric(DataType.WORD, ctx.mem.getSWord(address))
+                            DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, ctx.mem.getFloat(address))
+                            DataType.STR -> RuntimeValueString(ctx.mem.getString(address), null)
+                            else -> throw VmExecutionException("unexpected datatype $variable")
+                        }
+                    }
+                }
+            } else
+                throw VmExecutionException("weird identifier reference $variable")
+        }
+        is FunctionCall -> {
+            val sub = expr.target.targetStatement(ctx.program.namespace)
+            val args = expr.args.map { evaluate(it, ctx) as RuntimeValueNumeric }
+            return when(sub) {
+                is Subroutine -> {
+                    val result = ctx.executeSubroutine(sub, args, null)
+                            ?: throw VmExecutionException("expected a result from functioncall $expr")
+                    result
+                }
+                is BuiltinFunctionStatementPlaceholder -> {
+                    val result = ctx.performBuiltinFunction(sub.name, args, ctx.statusflags)
+                            ?: throw VmExecutionException("expected 1 result from functioncall $expr")
+                    result
+                }
+                else -> {
+                    throw VmExecutionException("unimplemented function call target $sub")
+                }
+            }
+        }
+        is RangeExpr -> {
+            val cRange = expr.toConstantIntegerRange()
+            if(cRange!=null) {
+                val dt = expr.inferType(ctx.program)
+                if(dt.isKnown)
+                    return RuntimeValueRange(dt.typeOrElse(DataType.UBYTE), cRange)
+                else
+                    throw VmExecutionException("couldn't determine datatype")
+            }
+            val fromVal = (evaluate(expr.from, ctx) as RuntimeValueNumeric).integerValue()
+            val toVal = (evaluate(expr.to, ctx) as RuntimeValueNumeric).integerValue()
+            val stepVal = (evaluate(expr.step, ctx) as RuntimeValueNumeric).integerValue()
+            val range = makeRange(fromVal, toVal, stepVal)
+            val dt = expr.inferType(ctx.program)
+            if(dt.isKnown)
+                return RuntimeValueRange(dt.typeOrElse(DataType.UBYTE), range)
+            else
+                throw VmExecutionException("couldn't determine datatype")
+        }
+        else -> {
+            throw VmExecutionException("unimplemented expression node $expr")
+        }
+    }
+}

compiler/src/prog8/vm/astvm/Memory.kt

@@ -0,0 +1,122 @@
+package prog8.vm.astvm
+
+import prog8.compiler.target.CompilationTarget
+import prog8.compiler.target.c64.C64MachineDefinition
+import kotlin.math.abs
+
+class Memory(private val readObserver: (address: Int, value: Short) -> Short,
+             private val writeObserver: (address: Int, value: Short) -> Short)
+{
+
+    private val mem = ShortArray(65536)         // shorts because byte is signed and we store values 0..255
+    private val observed = BooleanArray(65536)     // what addresses are observed
+
+
+    fun observe(vararg address: Int) {
+        address.forEach { observed[it]=true }
+    }
+
+    fun getUByte(address: Int): Short {
+        return if(observed[address]) readObserver(address, mem[address])
+        else mem[address]
+    }
+
+    fun getUByteDirectly(address: Int): Short {
+        return mem[address]
+    }
+
+    fun getSByte(address: Int): Short {
+        val ubyte = getUByte(address)
+        return if(ubyte <= 127) ubyte
+        else (-((ubyte.toInt() xor 255)+1)).toShort()   // 2's complement
+    }
+
+    fun setUByte(address: Int, value: Short) {
+        if(value !in 0..255)
+            throw VmExecutionException("ubyte value out of range $value")
+        mem[address] =
+                if(observed[address]) writeObserver(address, value)
+                else value
+    }
+
+    fun setUByteDirectly(address: Int, value: Short) {
+        if(value !in 0..255)
+            throw VmExecutionException("ubyte value out of range $value")
+        mem[address] = value
+    }
+
+    fun setSByte(address: Int, value: Short) {
+        if(value !in -128..127) throw VmExecutionException("byte value out of range $value")
+        val ubyte =
+                if(value>=0) value
+                else ((abs(value.toInt()) xor 255)+1).toShort()        // 2's complement
+        setUByte(address, ubyte)
+    }
+
+    fun getUWord(address: Int): Int {
+        return getUByte(address) + 256*getUByte(address+1)
+    }
+
+    fun getSWord(address: Int): Int {
+        val uword = getUWord(address)
+        if(uword <= 32767)
+            return uword
+        return -((uword xor 65535)+1)   // 2's complement
+    }
+
+    fun setUWord(address: Int, value: Int) {
+        if(value !in 0..65535)
+            throw VmExecutionException("uword value out of range $value")
+        setUByte(address, value.and(255).toShort())
+        setUByte(address+1, (value / 256).toShort())
+    }
+
+    fun setSWord(address: Int, value: Int) {
+        if(value !in -32768..32767) throw VmExecutionException("word value out of range $value")
+        if(value>=0)
+            setUWord(address, value)
+        else
+            setUWord(address, (abs(value) xor 65535)+1)        // 2's complement
+    }
+
+    fun setFloat(address: Int, value: Double) {
+        val mflpt5 = C64MachineDefinition.Mflpt5.fromNumber(value)
+        setUByte(address, mflpt5.b0)
+        setUByte(address+1, mflpt5.b1)
+        setUByte(address+2, mflpt5.b2)
+        setUByte(address+3, mflpt5.b3)
+        setUByte(address+4, mflpt5.b4)
+    }
+
+    fun getFloat(address: Int): Double {
+        return C64MachineDefinition.Mflpt5(getUByte(address), getUByte(address + 1), getUByte(address + 2),
+                getUByte(address + 3), getUByte(address + 4)).toDouble()
+    }
+
+    fun setString(address: Int, str: String) {
+        val encoded = CompilationTarget.encodeString(str)
+        var addr = address
+        for (c in encoded) setUByte(addr++, c)
+        setUByte(addr, 0)
+    }
+
+    fun getString(strAddress: Int): String {
+        val encoded = mutableListOf<Short>()
+        var addr = strAddress
+        while(true) {
+            val byte = getUByte(addr++)
+            if(byte==0.toShort()) break
+            encoded.add(byte)
+        }
+        return CompilationTarget.decodeString(encoded)
+    }
+
+    fun clear() {
+        for(i in 0..65535) setUByte(i, 0)
+    }
+
+    fun copy(from: Int, to: Int, numbytes: Int) {
+        for(i in 0 until numbytes)
+            setUByte(to+i, getUByte(from+i))
+    }
+}

compiler/src/prog8/vm/astvm/ScreenDialog.kt

@@ -1,12 +1,12 @@
-package prog8.astvm
+package prog8.vm.astvm
 
-import prog8.compiler.target.c64.Charset
-import prog8.compiler.target.c64.Colors
+import prog8.compiler.target.c64.C64MachineDefinition
 import prog8.compiler.target.c64.Petscii
 import java.awt.*
 import java.awt.event.KeyEvent
 import java.awt.event.KeyListener
 import java.awt.image.BufferedImage
+import java.util.ArrayDeque
 import javax.swing.JFrame
 import javax.swing.JPanel
 import javax.swing.Timer
@@ -18,6 +18,7 @@ class BitmapScreenPanel : KeyListener, JPanel() {
     private val g2d = image.graphics as Graphics2D
     private var cursorX: Int=0
     private var cursorY: Int=0
+    val keyboardBuffer = ArrayDeque<Char>()
 
     init {
         val size = Dimension(image.width * SCALING, image.height * SCALING)
@@ -30,14 +31,14 @@ class BitmapScreenPanel : KeyListener, JPanel() {
         addKeyListener(this)
     }
 
-    override fun keyTyped(p0: KeyEvent?) {}
+    override fun keyTyped(p0: KeyEvent) {
+        keyboardBuffer.add(p0.keyChar)
+    }
 
-    override fun keyPressed(p0: KeyEvent?) {
-        println("pressed: $p0.k")
+    override fun keyPressed(p0: KeyEvent) {
     }
 
     override fun keyReleased(p0: KeyEvent?) {
-        println("released: $p0")
     }
 
     override fun paint(graphics: Graphics?) {
@@ -49,61 +50,57 @@ class BitmapScreenPanel : KeyListener, JPanel() {
     }
 
     fun clearScreen(color: Short) {
-        g2d.background = Colors.palette[color % Colors.palette.size]
+        g2d.background = C64MachineDefinition.colorPalette[color % C64MachineDefinition.colorPalette.size]
         g2d.clearRect(0, 0, SCREENWIDTH, SCREENHEIGHT)
         cursorX = 0
         cursorY = 0
     }
     fun setPixel(x: Int, y: Int, color: Short) {
-        image.setRGB(x, y, Colors.palette[color % Colors.palette.size].rgb)
+        image.setRGB(x, y, C64MachineDefinition.colorPalette[color % C64MachineDefinition.colorPalette.size].rgb)
     }
     fun drawLine(x1: Int, y1: Int, x2: Int, y2: Int, color: Short) {
-        g2d.color = Colors.palette[color % Colors.palette.size]
+        g2d.color = C64MachineDefinition.colorPalette[color % C64MachineDefinition.colorPalette.size]
         g2d.drawLine(x1, y1, x2, y2)
     }
-    fun printText(text: String, color: Short, lowercase: Boolean) {
+
+    fun printAsciiText(text: String) {
         val t2 = text.substringBefore(0.toChar())
-        val lines = t2.split('\n')
-        for(line in lines.withIndex()) {
-            printTextSingleLine(line.value, color, lowercase)
-            if(line.index<lines.size-1) {
-                cursorX=0
-                cursorY++
-            }
-        }
-    }
-    private fun printTextSingleLine(text: String, color: Short, lowercase: Boolean) {
-        for(clearx in cursorX until cursorX+text.length) {
-            g2d.clearRect(8*clearx, 8*y, 8, 8)
-        }
-        for(sc in Petscii.encodeScreencode(text, lowercase)) {
-            setChar(cursorX, cursorY, sc, color)
-            cursorX++
-            if(cursorX>=(SCREENWIDTH/8)) {
-                cursorY++
-                cursorX=0
-            }
-        }
+        val petscii = Petscii.encodePetscii(t2, true)
+        petscii.forEach { printPetsciiChar(it) }
     }
 
-    fun printChar(char: Short) {
-        if(char==13.toShort() || char==141.toShort()) {
+    fun printPetsciiChar(petscii: Short) {
+        if(petscii in listOf(0x0d.toShort(), 0x8d.toShort())) {
+            // Return and shift-Return
             cursorX=0
             cursorY++
         } else {
-            setChar(cursorX, cursorY, char, 1)
+            val scr = Petscii.petscii2scr(petscii, false)
+            setScreenChar(cursorX, cursorY, scr, 1)
             cursorX++
             if (cursorX >= (SCREENWIDTH / 8)) {
                 cursorY++
                 cursorX = 0
             }
         }
+        while(cursorY>=(SCREENHEIGHT/8)) {
+            // scroll the screen up because the cursor went past the last line
+            Thread.sleep(10)
+            val screen = image.copy()
+            val graphics = image.graphics as Graphics2D
+            graphics.drawImage(screen, 0, -8, null)
+            val color = graphics.color
+            graphics.color = C64MachineDefinition.colorPalette[6]
+            graphics.fillRect(0, 24*8, SCREENWIDTH, 25*8)
+            graphics.color=color
+            cursorY--
+        }
     }
 
-    fun setChar(x: Int, y: Int, screenCode: Short, color: Short) {
+    fun setScreenChar(x: Int, y: Int, screencode: Short, color: Short) {
         g2d.clearRect(8*x, 8*y, 8, 8)
-        val colorIdx = (color % Colors.palette.size).toShort()
-        val coloredImage = Charset.getColoredChar(screenCode, colorIdx)
+        val colorIdx = (color % C64MachineDefinition.colorPalette.size).toShort()
+        val coloredImage = C64MachineDefinition.Charset.getColoredChar(screencode, colorIdx)
         g2d.drawImage(coloredImage, 8*x, 8*y , null)
     }
 
@@ -116,20 +113,6 @@ class BitmapScreenPanel : KeyListener, JPanel() {
         return Pair(cursorX, cursorY)
     }
 
-    fun writeText(x: Int, y: Int, text: String, color: Short, lowercase: Boolean) {
-        val colorIdx = (color % Colors.palette.size).toShort()
-        var xx=x
-        for(clearx in xx until xx+text.length) {
-            g2d.clearRect(8*clearx, 8*y, 8, 8)
-        }
-        for(sc in Petscii.encodeScreencode(text, lowercase)) {
-            if(sc==0.toShort())
-                break
-            setChar(xx++, y, sc, colorIdx)
-        }
-    }
-
-
     companion object {
         const val SCREENWIDTH = 320
         const val SCREENHEIGHT = 200
@@ -138,32 +121,32 @@ class BitmapScreenPanel : KeyListener, JPanel() {
 }
 
 
-class ScreenDialog : JFrame() {
+class ScreenDialog(title: String) : JFrame(title) {
     val canvas = BitmapScreenPanel()
+    val keyboardBuffer = canvas.keyboardBuffer
 
     init {
         val borderWidth = 16
-        title = "AstVm graphics. Text I/O goes to console."
         layout = GridBagLayout()
-        defaultCloseOperation = JFrame.EXIT_ON_CLOSE
+        defaultCloseOperation = EXIT_ON_CLOSE
         isResizable = false
 
         // the borders (top, left, right, bottom)
         val borderTop = JPanel().apply {
-            preferredSize = Dimension(BitmapScreenPanel.SCALING * (BitmapScreenPanel.SCREENWIDTH+2*borderWidth), BitmapScreenPanel.SCALING * borderWidth)
-            background = Colors.palette[14]
+            preferredSize = Dimension(BitmapScreenPanel.SCALING * (BitmapScreenPanel.SCREENWIDTH +2*borderWidth), BitmapScreenPanel.SCALING * borderWidth)
+            background = C64MachineDefinition.colorPalette[14]
         }
         val borderBottom = JPanel().apply {
-            preferredSize =Dimension(BitmapScreenPanel.SCALING * (BitmapScreenPanel.SCREENWIDTH+2*borderWidth), BitmapScreenPanel.SCALING * borderWidth)
-            background = Colors.palette[14]
+            preferredSize =Dimension(BitmapScreenPanel.SCALING * (BitmapScreenPanel.SCREENWIDTH +2*borderWidth), BitmapScreenPanel.SCALING * borderWidth)
+            background = C64MachineDefinition.colorPalette[14]
         }
         val borderLeft = JPanel().apply {
             preferredSize =Dimension(BitmapScreenPanel.SCALING * borderWidth, BitmapScreenPanel.SCALING * BitmapScreenPanel.SCREENHEIGHT)
-            background = Colors.palette[14]
+            background = C64MachineDefinition.colorPalette[14]
         }
         val borderRight = JPanel().apply {
             preferredSize =Dimension(BitmapScreenPanel.SCALING * borderWidth, BitmapScreenPanel.SCALING * BitmapScreenPanel.SCREENHEIGHT)
-            background = Colors.palette[14]
+            background = C64MachineDefinition.colorPalette[14]
         }
         var c = GridBagConstraints()
         c.gridx=0; c.gridy=1; c.gridwidth=3
@@ -190,3 +173,12 @@ class ScreenDialog : JFrame() {
         repaintTimer.start()
     }
 }
+
+
+private fun BufferedImage.copy(): BufferedImage {
+    val bcopy = BufferedImage(this.width, this.height, this.type)
+    val g = bcopy.graphics
+    g.drawImage(this, 0, 0, null)
+    g.dispose()
+    return bcopy
+}