regenerate skeletons and set version 10.4

This makes the naming consistent with the other cbm-like targets (c64, pet, c128). Only the x16 specific ones remain in the cx16 namespace, such as cx16.KEYHDL

Probably the most impactful is the move of cx16.CINV to cbm.CINV

.github/FUNDING.yml

@@ -0,0 +1,13 @@
+# These are supported funding model platforms
+
+#github: # Replace with up to 4 GitHub Sponsors-enabled usernames e.g., [user1, user2]
+#patreon: # Replace with a single Patreon username
+open_collective: # Replace with a single Open Collective username
+ko_fi: irmen
+#tidelift: # Replace with a single Tidelift platform-name/package-name e.g., npm/babel
+#community_bridge: # Replace with a single Community Bridge project-name e.g., cloud-foundry
+#liberapay: # Replace with a single Liberapay username
+#issuehunt: # Replace with a single IssueHunt username
+#otechie: # Replace with a single Otechie username
+#lfx_crowdfunding: # Replace with a single LFX Crowdfunding project-name e.g., cloud-foundry
+#custom: # Replace with up to 4 custom sponsorship URLs e.g., ['link1', 'link2']

.github/workflows/all-ci.yml

@@ -0,0 +1,41 @@
+name: Build and Test the Prog8 compiler
+
+on:
+  push:
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: build and install recent 64tass
+        run: |
+          sudo apt-get install -y make build-essential
+          git clone --depth=1 https://github.com/irmen/64tass
+          cd 64tass
+          make -j4
+          sudo make install          
+
+      - name: Set up JDK 11
+        uses: actions/setup-java@v4
+        with:
+          java-version: 11
+          distribution: temurin
+
+      - name: Build and test with Gradle
+        run: |
+          ./gradlew build shadowJar --no-daemon
+          sha256sum -b compiler/build/libs/*-all.jar > compiler/build/libs/hash.txt
+        
+      - name: Create compiler shadowJar artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: prog8-compiler-jar-zipped
+          path: |
+            compiler/build/libs/*-all.jar
+            compiler/build/libs/hash.txt
+

.gitignore

@@ -1,8 +1,8 @@
 .idea/workspace.xml
 .idea/discord.xml
-/build/
-/dist/
-/output/
+build/
+dist/
+output/
 .*cache/
 *.directory
 *.prg
@@ -12,9 +12,10 @@
 *.vice-mon-list
 docs/build
 out/
-**/*.interp
-**/*.tokens
-
+parser/**/*.interp
+parser/**/*.tokens
+parser/**/*.java
+compiler/src/prog8/buildversion/*
 *.py[cod]
 *.egg
 *.egg-info
@@ -26,7 +27,10 @@ parser.out
 parsetab.py
 .pytest_cache/
 .attach_pid*
+compiler/lib/
 
 .gradle
-build/
 /prog8compiler.jar
+sd*.img
+*.d64
+

.idea/codeInsightSettings.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="JavaProjectCodeInsightSettings">
+    <excluded-names>
+      <name>kotlin.Result</name>
+    </excluded-names>
+  </component>
+</project>

.idea/codeStyles/Project.xml

@@ -0,0 +1,10 @@
+<component name="ProjectCodeStyleConfiguration">
+  <code_scheme name="Project" version="173">
+    <JetCodeStyleSettings>
+      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
+    </JetCodeStyleSettings>
+    <codeStyleSettings language="kotlin">
+      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
+    </codeStyleSettings>
+  </code_scheme>
+</component>

.idea/codeStyles/codeStyleConfig.xml

@@ -0,0 +1,5 @@
+<component name="ProjectCodeStyleConfiguration">
+  <state>
+    <option name="USE_PER_PROJECT_SETTINGS" value="true" />
+  </state>
+</component>

.idea/compiler.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="CompilerConfiguration">
+    <option name="BUILD_PROCESS_HEAP_SIZE" value="3000" />
+    <bytecodeTargetLevel target="11" />
+  </component>
+</project>

.idea/inspectionProfiles/Project_Default.xml

@@ -3,14 +3,21 @@
     <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" />
+        <language isEnabled="false" name="Groovy" />
       </Languages>
     </inspection_tool>
+    <inspection_tool class="IncompleteDestructuring" enabled="true" level="WARNING" enabled_by_default="true" />
+    <inspection_tool class="PyInterpreterInspection" enabled="false" level="WARNING" enabled_by_default="false" />
+    <inspection_tool class="PyPackageRequirementsInspection" enabled="true" level="WARNING" enabled_by_default="true">
+      <option name="ignoredPackages">
+        <value>
+          <list size="1">
+            <item index="0" class="java.lang.String" itemvalue="sphinx_rtd_theme" />
+          </list>
+        </value>
+      </option>
+    </inspection_tool>
     <inspection_tool class="SpellCheckingInspection" enabled="true" level="TYPO" enabled_by_default="true">
       <option name="processCode" value="false" />
       <option name="processLiterals" value="true" />

.idea/kotlinc.xml

@@ -1,6 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="Kotlin2JvmCompilerArguments">
-    <option name="jvmTarget" value="1.8" />
+    <option name="jvmTarget" value="11" />
   </component>
-</project>
+  <component name="KotlinJpsPluginSettings">
+    <option name="version" value="1.9.24" />
+  </component>
+</project>

.idea/libraries/KotlinJavaRuntime.xml

@@ -1,19 +1,23 @@
 <component name="libraryTable">
-  <library name="KotlinJavaRuntime">
+  <library name="KotlinJavaRuntime" type="repository">
+    <properties maven-id="org.jetbrains.kotlin:kotlin-stdlib-jdk8:2.0.20" />
     <CLASSES>
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-stdlib.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-reflect.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-test.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-stdlib-jdk7.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-stdlib-jdk8.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/2.0.20/kotlin-stdlib-jdk8-2.0.20.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/2.0.20/kotlin-stdlib-2.0.20.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/2.0.20/kotlin-stdlib-jdk7-2.0.20.jar!/" />
     </CLASSES>
-    <JAVADOC />
+    <JAVADOC>
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/2.0.20/kotlin-stdlib-jdk8-2.0.20-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/2.0.20/kotlin-stdlib-2.0.20-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/2.0.20/kotlin-stdlib-jdk7-2.0.20-javadoc.jar!/" />
+    </JAVADOC>
     <SOURCES>
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-stdlib-sources.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-reflect-sources.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-test-sources.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-stdlib-jdk7-sources.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-stdlib-jdk8-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/2.0.20/kotlin-stdlib-jdk8-2.0.20-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/2.0.20/kotlin-stdlib-2.0.20-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/2.0.20/kotlin-stdlib-jdk7-2.0.20-sources.jar!/" />
     </SOURCES>
   </library>
 </component>

.idea/libraries/antlr_4_7_2_complete.xml

@@ -1,9 +0,0 @@
-<component name="libraryTable">
-  <library name="antlr-4.7.2-complete">
-    <CLASSES>
-      <root url="jar://$PROJECT_DIR$/parser/antlr/lib/antlr-4.7.2-complete.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>

.idea/libraries/antlr_antlr4.xml

@@ -0,0 +1,18 @@
+<component name="libraryTable">
+  <library name="antlr.antlr4" type="repository">
+    <properties maven-id="org.antlr:antlr4:4.13.2">
+      <exclude>
+        <dependency maven-id="com.ibm.icu:icu4j" />
+      </exclude>
+    </properties>
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4/4.13.2/antlr4-4.13.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4-runtime/4.13.2/antlr4-runtime-4.13.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr-runtime/3.5.3/antlr-runtime-3.5.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/ST4/4.3.4/ST4-4.3.4.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/abego/treelayout/org.abego.treelayout.core/1.0.3/org.abego.treelayout.core-1.0.3.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>

.idea/libraries/antlr_runtime_4_7_2.xml

@@ -1,9 +0,0 @@
-<component name="libraryTable">
-  <library name="antlr-runtime-4.7.2">
-    <CLASSES>
-      <root url="jar://$PROJECT_DIR$/parser/antlr/lib/antlr-runtime-4.7.2.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>

.idea/libraries/io_kotest_assertions_core_jvm.xml

@@ -0,0 +1,20 @@
+<component name="libraryTable">
+  <library name="io.kotest.assertions.core.jvm" type="repository">
+    <properties maven-id="io.kotest:kotest-assertions-core-jvm:5.9.1" />
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.9.1/kotest-assertions-core-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.9.1/kotest-assertions-shared-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/github/java-diff-utils/java-diff-utils/4.12/java-diff-utils-4.12.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.3.0/opentest4j-1.3.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.9.23/kotlin-stdlib-1.9.23.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.8.0/kotlinx-coroutines-jdk8-1.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.9.23/kotlin-reflect-1.9.23.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.9.1/kotest-common-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.9.1/kotest-assertions-api-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.8.0/kotlinx-coroutines-core-jvm-1.8.0.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>

.idea/libraries/io_kotest_runner_junit5_jvm.xml

@@ -0,0 +1,41 @@
+<component name="libraryTable">
+  <library name="io.kotest.runner.junit5.jvm" type="repository">
+    <properties maven-id="io.kotest:kotest-runner-junit5-jvm:5.9.1" />
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-runner-junit5-jvm/5.9.1/kotest-runner-junit5-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-api-jvm/5.9.1/kotest-framework-api-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.9.1/kotest-assertions-shared-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/github/java-diff-utils/java-diff-utils/4.12/java-diff-utils-4.12.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-test-jvm/1.8.0/kotlinx-coroutines-test-jvm-1.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.9.1/kotest-common-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-engine-jvm/5.9.1/kotest-framework-engine-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/github/classgraph/classgraph/4.8.172/classgraph-4.8.172.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/com/github/ajalt/mordant/1.2.1/mordant-1.2.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/com/github/ajalt/colormath/1.2.0/colormath-1.2.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.3.0/opentest4j-1.3.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-debug/1.8.0/kotlinx-coroutines-debug-1.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/net/java/dev/jna/jna/5.9.0/jna-5.9.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/net/java/dev/jna/jna-platform/5.9.0/jna-platform-5.9.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/net/bytebuddy/byte-buddy/1.10.9/byte-buddy-1.10.9.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/net/bytebuddy/byte-buddy-agent/1.10.9/byte-buddy-agent-1.10.9.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-discovery-jvm/5.9.1/kotest-framework-discovery-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.9.1/kotest-assertions-core-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.8.0/kotlinx-coroutines-jdk8-1.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.9.1/kotest-assertions-api-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-extensions-jvm/5.9.1/kotest-extensions-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-concurrency-jvm/5.9.1/kotest-framework-concurrency-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.8.0/kotlinx-coroutines-core-jvm-1.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/23.0.0/annotations-23.0.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-engine/1.8.2/junit-platform-engine-1.8.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-commons/1.8.2/junit-platform-commons-1.8.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/apiguardian/apiguardian-api/1.1.2/apiguardian-api-1.1.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-suite-api/1.8.2/junit-platform-suite-api-1.8.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-launcher/1.8.2/junit-platform-launcher-1.8.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-api/5.8.2/junit-jupiter-api-5.8.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.9.23/kotlin-stdlib-1.9.23.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.9.23/kotlin-reflect-1.9.23.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>

.idea/libraries/jetbrains_kotlinx_cli_jvm.xml

@@ -0,0 +1,10 @@
+<component name="libraryTable">
+  <library name="jetbrains.kotlinx.cli.jvm" type="repository">
+    <properties include-transitive-deps="false" maven-id="org.jetbrains.kotlinx:kotlinx-cli-jvm:0.3.6" />
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-cli-jvm/0.3.6/kotlinx-cli-jvm-0.3.6.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>

.idea/libraries/kotlinx_cli_jvm_0_1_0_dev_5.xml

@@ -1,9 +0,0 @@
-<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/libraries/michael_bull_kotlin_result_jvm.xml

@@ -0,0 +1,12 @@
+<component name="libraryTable">
+  <library name="michael.bull.kotlin.result.jvm" type="repository">
+    <properties maven-id="com.michael-bull.kotlin-result:kotlin-result-jvm:2.0.0" />
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/com/michael-bull/kotlin-result/kotlin-result-jvm/2.0.0/kotlin-result-jvm-2.0.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.9.22/kotlin-stdlib-1.9.22.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>

.idea/libraries/unittest_libs.xml

@@ -1,10 +0,0 @@
-<component name="libraryTable">
-  <library name="unittest-libs">
-    <CLASSES>
-      <root url="file://$PROJECT_DIR$/compiler/lib" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-    <jarDirectory url="file://$PROJECT_DIR$/compiler/lib" recursive="false" />
-  </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

@@ -1,6 +1,28 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="false" project-jdk-name="Kotlin SDK" project-jdk-type="KotlinSDK">
+  <component name="ANTLRGenerationPreferences">
+    <option name="perGrammarGenerationSettings">
+      <list>
+        <PerGrammarGenerationSettings>
+          <option name="fileName" value="$PROJECT_DIR$/parser/antlr/Prog8ANTLR.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="Black">
+    <option name="sdkName" value="Python 3.11" />
+  </component>
+  <component name="FrameworkDetectionExcludesConfiguration">
+    <type id="Python" />
+  </component>
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="openjdk-17" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>

.idea/modules.xml

@@ -2,11 +2,19 @@
 <project version="4">
   <component name="ProjectModuleManager">
     <modules>
-      <module fileurl="file://$PROJECT_DIR$/OldCodeGen/OldCodeGen.iml" filepath="$PROJECT_DIR$/OldCodeGen/OldCodeGen.iml" />
+      <module fileurl="file://$PROJECT_DIR$/codeCore/codeCore.iml" filepath="$PROJECT_DIR$/codeCore/codeCore.iml" />
+      <module fileurl="file://$PROJECT_DIR$/codeGenCpu6502/codeGenCpu6502.iml" filepath="$PROJECT_DIR$/codeGenCpu6502/codeGenCpu6502.iml" />
+      <module fileurl="file://$PROJECT_DIR$/codeGenExperimental/codeGenExperimental.iml" filepath="$PROJECT_DIR$/codeGenExperimental/codeGenExperimental.iml" />
+      <module fileurl="file://$PROJECT_DIR$/codeGenIntermediate/codeGenIntermediate.iml" filepath="$PROJECT_DIR$/codeGenIntermediate/codeGenIntermediate.iml" />
+      <module fileurl="file://$PROJECT_DIR$/codeGenVirtual/codeGenVirtual.iml" filepath="$PROJECT_DIR$/codeGenVirtual/codeGenVirtual.iml" />
+      <module fileurl="file://$PROJECT_DIR$/codeOptimizers/codeOptimizers.iml" filepath="$PROJECT_DIR$/codeOptimizers/codeOptimizers.iml" />
       <module fileurl="file://$PROJECT_DIR$/compiler/compiler.iml" filepath="$PROJECT_DIR$/compiler/compiler.iml" />
+      <module fileurl="file://$PROJECT_DIR$/compilerAst/compilerAst.iml" filepath="$PROJECT_DIR$/compilerAst/compilerAst.iml" />
       <module fileurl="file://$PROJECT_DIR$/docs/docs.iml" filepath="$PROJECT_DIR$/docs/docs.iml" />
       <module fileurl="file://$PROJECT_DIR$/examples/examples.iml" filepath="$PROJECT_DIR$/examples/examples.iml" />
+      <module fileurl="file://$PROJECT_DIR$/intermediate/intermediate.iml" filepath="$PROJECT_DIR$/intermediate/intermediate.iml" />
       <module fileurl="file://$PROJECT_DIR$/parser/parser.iml" filepath="$PROJECT_DIR$/parser/parser.iml" />
+      <module fileurl="file://$PROJECT_DIR$/virtualmachine/virtualmachine.iml" filepath="$PROJECT_DIR$/virtualmachine/virtualmachine.iml" />
     </modules>
   </component>
 </project>

.idea/vcs.xml

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

.readthedocs.yaml

@@ -0,0 +1,27 @@
+# .readthedocs.yaml
+# Read the Docs configuration file
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+
+# Required
+version: 2
+
+# Set the version of Python and other tools you might need
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.12"
+
+# Optionally declare the Python requirements required to build your docs
+python:
+  install:
+    - requirements: docs/requirements.txt
+
+# Build documentation in the docs/ directory with Sphinx
+sphinx:
+  configuration: docs/source/conf.py
+  fail_on_warning: true
+
+# If using Sphinx, optionally build your docs in additional formats such as PDF
+formats:
+  - pdf
+  - epub

.travis.yml

@@ -1,11 +0,0 @@
-language: java
-sudo: false
-# jdk: openjdk8
-# dist: xenial
-
-before_install:
-  - chmod +x gradlew
-
-script:
-  - gradle test
-

LICENSE

@@ -1,3 +1,13 @@
+
+This sofware license is for Prog8 the compiler + associated library files.
+
+Exception: All output files generated by the compiler (intermediary files
+and compiled binary programs) are excluded from this; you can do with those
+whatever you want.
+
+
+
+
                     GNU GENERAL PUBLIC LICENSE
                        Version 3, 29 June 2007
 

Makefile

@@ -0,0 +1,12 @@
+# super simple Makefile to lauch the main gradle targets to build and/or test the prog8 compiler
+
+.PHONY: all test
+
+all:
+	gradle installdist installshadowdist
+	@echo "compiler launch script can be found here: compiler/build/install/compiler-shadow/bin/p8compile"
+
+test:
+	gradle build
+	@echo "compiler launch script can be found here: compiler/build/install/compiler-shadow/bin/p8compile"
+

OldCodeGen/src/oldcodegen/AsmGen.kt

@@ -1,762 +0,0 @@
-package oldcodegen
-
-/** OLD STACK-VM CODE GEN -- NO LONGER USED **/
-
-// note: to put stuff on the stack, we use Absolute,X  addressing mode which is 3 bytes / 4 cycles
-// possible space optimization is to use zeropage (indirect),Y  which is 2 bytes, but 5 cycles
-
-import prog8.ast.antlr.escape
-import prog8.ast.base.DataType
-import prog8.ast.base.initvarsSubName
-import prog8.ast.statements.ZeropageWish
-import prog8.compiler.*
-import prog8.compiler.intermediate.Instruction
-import prog8.compiler.intermediate.IntermediateProgram
-import prog8.compiler.intermediate.LabelInstr
-import prog8.compiler.intermediate.Opcode
-import prog8.compiler.target.c64.AssemblyProgram
-import prog8.compiler.target.c64.MachineDefinition
-import prog8.compiler.target.c64.Petscii
-import prog8.vm.RuntimeValue
-import java.io.File
-import kotlin.math.abs
-
-
-class AssemblyError(msg: String) : RuntimeException(msg)
-
-
-
-internal fun intVal(valueInstr: Instruction) = valueInstr.arg!!.integerValue()
-internal fun hexVal(valueInstr: Instruction) = valueInstr.arg!!.integerValue().toHex()
-internal fun hexValPlusOne(valueInstr: Instruction) = (valueInstr.arg!!.integerValue()+1).toHex()
-internal fun getFloatConst(value: RuntimeValue): String =
-        globalFloatConsts[value.numericValue().toDouble()]
-                ?: throw AssemblyError("should have a global float const for number $value")
-
-internal val globalFloatConsts = mutableMapOf<Double, String>()
-
-internal fun signExtendA(into: String) =
-        """
-        ora  #$7f
-        bmi  +
-        lda  #0
-+       sta  $into
-        """
-
-class AsmGen(private val options: CompilationOptions, private val program: IntermediateProgram,
-             private val heap: HeapValues, private val zeropage: Zeropage) {
-    private val assemblyLines = mutableListOf<String>()
-    private lateinit var block: IntermediateProgram.ProgramBlock
-
-    init {
-        // Convert invalid label names (such as "<anon-1>") to something that's allowed.
-        val newblocks = mutableListOf<IntermediateProgram.ProgramBlock>()
-        for(block in program.blocks) {
-            val newvars = block.variables.map { IntermediateProgram.Variable(symname(it.scopedname, block), it.value, it.params) }.toMutableList()
-            val newlabels = block.labels.map { symname(it.key, block) to it.value}.toMap().toMutableMap()
-            val newinstructions = block.instructions.asSequence().map {
-                when {
-                    it is LabelInstr -> LabelInstr(symname(it.name, block), it.asmProc)
-                    it.opcode == Opcode.INLINE_ASSEMBLY -> it
-                    else ->
-                        Instruction(it.opcode, it.arg, it.arg2,
-                            callLabel = if (it.callLabel != null) symname(it.callLabel, block) else null,
-                            callLabel2 = if (it.callLabel2 != null) symname(it.callLabel2, block) else null)
-                }
-            }.toMutableList()
-            val newMempointers = block.memoryPointers.map { symname(it.key, block) to it.value }.toMap().toMutableMap()
-            val newblock = IntermediateProgram.ProgramBlock(
-                    block.name,
-                    block.address,
-                    newinstructions,
-                    newvars,
-                    newMempointers,
-                    newlabels,
-                    force_output = block.force_output)
-            newblocks.add(newblock)
-        }
-        program.blocks.clear()
-        program.blocks.addAll(newblocks)
-
-        val newAllocatedZp = program.allocatedZeropageVariables.map { symname(it.key, null) to it.value}
-        program.allocatedZeropageVariables.clear()
-        program.allocatedZeropageVariables.putAll(newAllocatedZp)
-
-        // make a list of all const floats that are used
-        for(block in program.blocks) {
-            for(ins in block.instructions.filter{it.arg?.type== DataType.FLOAT}) {
-                val float = ins.arg!!.numericValue().toDouble()
-                if(float !in globalFloatConsts)
-                    globalFloatConsts[float] = "prog8_const_float_${globalFloatConsts.size}"
-            }
-        }
-    }
-
-    fun compileToAssembly(optimize: Boolean): AssemblyProgram {
-        println("Generating assembly code from intermediate code... ")
-
-        assemblyLines.clear()
-        header()
-        for(b in program.blocks)
-            block2asm(b)
-
-        if(optimize) {
-            var optimizationsDone = 1
-            while (optimizationsDone > 0) {
-                optimizationsDone = optimizeAssembly(assemblyLines)
-            }
-        }
-
-        File("${program.name}.asm").printWriter().use {
-            for (line in assemblyLines) { it.println(line) }
-        }
-
-        return AssemblyProgram(program.name)
-    }
-
-    private fun out(str: String, splitlines: Boolean=true) {
-        if(splitlines) {
-            for (line in str.split('\n')) {
-                val trimmed = if (line.startsWith(' ')) "\t" + line.trim() else line.trim()
-                // trimmed = trimmed.replace(Regex("^\\+\\s+"), "+\t")  // sanitize local label indentation
-                assemblyLines.add(trimmed)
-            }
-        } else assemblyLines.add(str)
-    }
-
-
-    // convert a fully scoped name (defined in the given block) to a valid assembly symbol name
-    private fun symname(scoped: String, block: IntermediateProgram.ProgramBlock?): String {
-        if(' ' in scoped)
-            return scoped
-        val blockLocal: Boolean
-        var name = if (block!=null && scoped.startsWith("${block.name}.")) {
-            blockLocal = true
-            scoped.substring(block.name.length+1)
-        }
-        else {
-            blockLocal = false
-            scoped
-        }
-        name = name.replace("<", "prog8_").replace(">", "")     // take care of the autogenerated invalid (anon) label names
-        if(name=="-")
-            return "-"
-        if(blockLocal)
-            name = name.replace(".", "_")
-        else {
-            val parts = name.split(".", limit=2)
-            if(parts.size>1)
-                name = "${parts[0]}.${parts[1].replace(".", "_")}"
-        }
-        return name.replace("-", "")
-    }
-
-    private fun makeFloatFill(flt: MachineDefinition.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, $b4"
-    }
-
-    private fun header() {
-        val ourName = this.javaClass.name
-        out("; 6502 assembly code for '${program.name}'")
-        out("; generated by $ourName on ${Date()}")
-        out("; assembler syntax is for the 64tasm cross-assembler")
-        out("; output options: output=${options.output} launcher=${options.launcher} zp=${options.zeropage}")
-        out("\n.cpu  '6502'\n.enc  'none'\n")
-
-        if(program.loadAddress==0)   // fix load address
-            program.loadAddress = if(options.launcher==LauncherType.BASIC)
-                MachineDefinition.BASIC_LOAD_ADDRESS else MachineDefinition.RAW_LOAD_ADDRESS
-
-        when {
-            options.launcher == LauncherType.BASIC -> {
-                if (program.loadAddress != 0x0801)
-                    throw AssemblyError("BASIC output must have load address $0801")
-                out("; ---- basic program with sys call ----")
-                out("* = ${program.loadAddress.toHex()}")
-                val year = Calendar.getInstance().get(Calendar.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.loadAddress.toHex()}\n")
-                out("  jsr  prog8_lib.init_system")
-            }
-            options.output == OutputType.RAW -> {
-                out("; ---- raw assembler program ----")
-                out("* = ${program.loadAddress.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.blocks) {
-            val initVarsLabel = block.instructions.firstOrNull { it is LabelInstr && it.name== initvarsSubName } as? LabelInstr
-            if(initVarsLabel!=null)
-                out("  jsr  ${block.name}.${initVarsLabel.name}")
-        }
-        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("")
-
-        // the global list of all floating point constants for the whole program
-        for(flt in globalFloatConsts) {
-            val floatFill = makeFloatFill(MachineDefinition.Mflpt5.fromNumber(flt.key))
-            out("${flt.value}\t.byte  $floatFill  ; float ${flt.key}")
-        }
-    }
-
-    private fun block2asm(blk: IntermediateProgram.ProgramBlock) {
-        block = blk
-        out("\n\n; ---- block: '${block.name}' ----")
-        if(!blk.force_output)
-            out("${block.name}\t.proc\n")
-        if(block.address!=null) {
-            out(".cerror * > ${block.address?.toHex()}, 'block address overlaps by ', *-${block.address?.toHex()},' bytes'")
-            out("* = ${block.address?.toHex()}")
-        }
-
-        // deal with zeropage variables
-        for(variable in blk.variables) {
-            val sym = symname(blk.name+"."+variable.scopedname, null)
-            val zpVar = program.allocatedZeropageVariables[sym]
-            if(zpVar==null) {
-                // This var is not on the ZP yet. Attempt to move it there (if it's not a float, those take up too much space)
-                if(variable.params.zp != ZeropageWish.NOT_IN_ZEROPAGE &&
-                        variable.value.type in zeropage.allowedDatatypes
-                        && variable.value.type != DataType.FLOAT) {
-                    try {
-                        val address = zeropage.allocate(sym, variable.value.type, null)
-                        out("${variable.scopedname} = $address\t; auto zp ${variable.value.type}")
-                        // make sure we add the var to the set of zpvars for this block
-                        program.allocatedZeropageVariables[sym] = Pair(address, variable.value.type)
-                    } catch (x: ZeropageDepletedError) {
-                        // leave it as it is.
-                    }
-                }
-            }
-            else {
-                // it was already allocated on the zp
-                out("${variable.scopedname} = ${zpVar.first}\t; zp ${zpVar.second}")
-            }
-        }
-
-        out("\n; memdefs and kernel subroutines")
-        memdefs2asm(block)
-        out("\n; non-zeropage variables")
-        vardecls2asm(block)
-        out("")
-
-        val instructionPatternWindowSize = 8        // increase once patterns occur longer than this.
-        var processed = 0
-
-        for (ins in block.instructions.windowed(instructionPatternWindowSize, partialWindows = true)) {
-            if (processed == 0) {
-                processed = instr2asm(ins)
-                if (processed == 0) {
-                    // the instructions are not recognised yet and can't be translated into assembly
-                    throw CompilerException("no asm translation found for instruction pattern: $ins")
-                }
-            }
-            processed--
-        }
-        if(!blk.force_output)
-            out("\n\t.pend\n")
-    }
-
-    private fun memdefs2asm(block: IntermediateProgram.ProgramBlock) {
-        for(m in block.memoryPointers) {
-            out("  ${m.key} = ${m.value.first.toHex()}")
-        }
-    }
-
-    private fun vardecls2asm(block: IntermediateProgram.ProgramBlock) {
-        val uniqueNames = block.variables.map { it.scopedname }.toSet()
-        if (uniqueNames.size != block.variables.size)
-            throw AssemblyError("not all variables have unique names")
-
-        // these are the non-zeropage variables.
-        // first get all the flattened struct members, they MUST remain in order
-        out(";  flattened struct members")
-        val (structMembers, normalVars) = block.variables.partition { it.params.memberOfStruct!=null }
-        structMembers.forEach { vardecl2asm(it.scopedname, it.value, it.params) }
-
-        // sort the other variables by type
-        out(";  other variables sorted by type")
-        val sortedVars = normalVars.sortedBy { it.value.type }
-        for (variable in sortedVars) {
-            val sym = symname(block.name + "." + variable.scopedname, null)
-            if(sym in program.allocatedZeropageVariables)
-                continue  // skip the ones that already belong in the zero page
-            vardecl2asm(variable.scopedname, variable.value, variable.params)
-        }
-    }
-
-    private fun vardecl2asm(varname: String, value: RuntimeValue, parameters: IntermediateProgram.VariableParameters) {
-        when (value.type) {
-            DataType.UBYTE -> out("$varname\t.byte  0")
-            DataType.BYTE -> out("$varname\t.char  0")
-            DataType.UWORD -> out("$varname\t.word  0")
-            DataType.WORD -> out("$varname\t.sint  0")
-            DataType.FLOAT -> out("$varname\t.byte  0,0,0,0,0  ; float")
-            DataType.STR, DataType.STR_S -> {
-                val rawStr = heap.get(value.heapId!!).str!!
-                val bytes = encodeStr(rawStr, value.type).map { "$" + it.toString(16).padStart(2, '0') }
-                out("$varname\t; ${value.type} \"${escape(rawStr).replace("\u0000", "<NULL>")}\"")
-                for (chunk in bytes.chunked(16))
-                    out("  .byte  " + chunk.joinToString())
-            }
-            DataType.ARRAY_UB -> {
-                // unsigned integer byte arraysize
-                val data = makeArrayFillDataUnsigned(value)
-                if (data.size <= 16)
-                    out("$varname\t.byte  ${data.joinToString()}")
-                else {
-                    out(varname)
-                    for (chunk in data.chunked(16))
-                        out("  .byte  " + chunk.joinToString())
-                }
-            }
-            DataType.ARRAY_B -> {
-                // signed integer byte arraysize
-                val data = makeArrayFillDataSigned(value)
-                if (data.size <= 16)
-                    out("$varname\t.char  ${data.joinToString()}")
-                else {
-                    out(varname)
-                    for (chunk in data.chunked(16))
-                        out("  .char  " + chunk.joinToString())
-                }
-            }
-            DataType.ARRAY_UW -> {
-                // unsigned word arraysize
-                val data = makeArrayFillDataUnsigned(value)
-                if (data.size <= 16)
-                    out("$varname\t.word  ${data.joinToString()}")
-                else {
-                    out(varname)
-                    for (chunk in data.chunked(16))
-                        out("  .word  " + chunk.joinToString())
-                }
-            }
-            DataType.ARRAY_W -> {
-                // signed word arraysize
-                val data = makeArrayFillDataSigned(value)
-                if (data.size <= 16)
-                    out("$varname\t.sint  ${data.joinToString()}")
-                else {
-                    out(varname)
-                    for (chunk in data.chunked(16))
-                        out("  .sint  " + chunk.joinToString())
-                }
-            }
-            DataType.ARRAY_F -> {
-                // float arraysize
-                val array = heap.get(value.heapId!!).doubleArray!!
-                val floatFills = array.map { makeFloatFill(MachineDefinition.Mflpt5.fromNumber(it)) }
-                out(varname)
-                for (f in array.zip(floatFills))
-                    out("  .byte  ${f.second}  ; float ${f.first}")
-            }
-            DataType.STRUCT -> throw AssemblyError("vars of type STRUCT should have been removed because flattened")
-        }
-    }
-
-
-    private fun encodeStr(str: String, dt: DataType): List<Short> {
-        return when(dt) {
-            DataType.STR -> {
-                val bytes = Petscii.encodePetscii(str, true)
-                bytes.plus(0)
-            }
-            DataType.STR_S -> {
-                val bytes = Petscii.encodeScreencode(str, true)
-                bytes.plus(0)
-            }
-            else -> throw AssemblyError("invalid str type")
-        }
-    }
-
-    private fun makeArrayFillDataUnsigned(value: RuntimeValue): List<String> {
-        val array = heap.get(value.heapId!!).array!!
-        return when {
-            value.type== DataType.ARRAY_UB ->
-                // byte array can never contain pointer-to types, so treat values as all integers
-                array.map { "$"+it.integer!!.toString(16).padStart(2, '0') }
-            value.type== DataType.ARRAY_UW -> array.map {
-                when {
-                    it.integer!=null -> "$"+it.integer.toString(16).padStart(2, '0')
-                    it.addressOf!=null -> symname(it.addressOf.scopedname!!, block)
-                    else -> throw AssemblyError("weird type in array")
-                }
-            }
-            else -> throw AssemblyError("invalid arraysize type")
-        }
-    }
-
-    private fun makeArrayFillDataSigned(value: RuntimeValue): List<String> {
-        val array = heap.get(value.heapId!!).array!!
-        // note: array of signed value can never contain pointer-to type, so simply accept values as being all integers
-        return if (value.type == DataType.ARRAY_B || value.type == DataType.ARRAY_W) {
-            array.map {
-                if(it.integer!!>=0)
-                    "$"+it.integer.toString(16).padStart(2, '0')
-                else
-                    "-$"+abs(it.integer).toString(16).padStart(2, '0')
-            }
-        }
-        else throw AssemblyError("invalid arraysize type")
-    }
-
-    private fun instr2asm(ins: List<Instruction>): Int {
-        // find best patterns (matching the most of the lines, then with the smallest weight)
-        val fragments = findPatterns(ins).sortedByDescending { it.segmentSize }
-        if(fragments.isEmpty()) {
-            // we didn't find any matching patterns (complex multi-instruction fragments), try simple ones
-            val firstIns = ins[0]
-            val singleAsm = simpleInstr2Asm(firstIns, block)
-            if(singleAsm != null) {
-                outputAsmFragment(singleAsm)
-                return 1
-            }
-            return 0
-        }
-        val best = fragments[0]
-        outputAsmFragment(best.asm)
-        return best.segmentSize
-    }
-
-    private fun outputAsmFragment(singleAsm: String) {
-        if (singleAsm.isNotEmpty()) {
-            if(singleAsm.startsWith("@inline@"))
-                out(singleAsm.substring(8), false)
-            else {
-                val withNewlines = singleAsm.replace('|', '\n')
-                out(withNewlines)
-            }
-        }
-    }
-
-    private fun findPatterns(segment: List<Instruction>): List<AsmFragment> {
-        val opcodes = segment.map { it.opcode }
-        val result = mutableListOf<AsmFragment>()
-
-        // check for operations that modify a single value, by putting it on the stack (and popping it afterwards)
-        if((opcodes[0]==Opcode.PUSH_VAR_BYTE && opcodes[2]==Opcode.POP_VAR_BYTE) ||
-                (opcodes[0]==Opcode.PUSH_VAR_WORD && opcodes[2]==Opcode.POP_VAR_WORD) ||
-                (opcodes[0]==Opcode.PUSH_VAR_FLOAT && opcodes[2]==Opcode.POP_VAR_FLOAT)) {
-            if (segment[0].callLabel == segment[2].callLabel) {
-                val fragment = sameVarOperation(segment[0].callLabel!!, segment[1])
-                if (fragment != null) {
-                    fragment.segmentSize = 3
-                    result.add(fragment)
-                }
-            }
-        }
-        else if((opcodes[0]==Opcode.PUSH_BYTE && opcodes[1] in setOf(Opcode.INC_INDEXED_VAR_B, Opcode.INC_INDEXED_VAR_UB,
-                        Opcode.INC_INDEXED_VAR_UW, Opcode.INC_INDEXED_VAR_W, Opcode.INC_INDEXED_VAR_FLOAT,
-                        Opcode.DEC_INDEXED_VAR_B, Opcode.DEC_INDEXED_VAR_UB, Opcode.DEC_INDEXED_VAR_W,
-                        Opcode.DEC_INDEXED_VAR_UW, Opcode.DEC_INDEXED_VAR_FLOAT))) {
-            val fragment = sameConstantIndexedVarOperation(segment[1].callLabel!!, segment[0].arg!!.integerValue(), segment[1])
-            if(fragment!=null) {
-                fragment.segmentSize=2
-                result.add(fragment)
-            }
-        }
-        else if((opcodes[0]==Opcode.PUSH_VAR_BYTE && opcodes[1] in setOf(Opcode.INC_INDEXED_VAR_B, Opcode.INC_INDEXED_VAR_UB,
-                        Opcode.INC_INDEXED_VAR_UW, Opcode.INC_INDEXED_VAR_W, Opcode.INC_INDEXED_VAR_FLOAT,
-                        Opcode.DEC_INDEXED_VAR_B, Opcode.DEC_INDEXED_VAR_UB, Opcode.DEC_INDEXED_VAR_W,
-                        Opcode.DEC_INDEXED_VAR_UW, Opcode.DEC_INDEXED_VAR_FLOAT))) {
-            val fragment = sameIndexedVarOperation(segment[1].callLabel!!, segment[0].callLabel!!, segment[1])
-            if(fragment!=null) {
-                fragment.segmentSize=2
-                result.add(fragment)
-            }
-        }
-        else if((opcodes[0]==Opcode.PUSH_MEM_UB && opcodes[2]==Opcode.POP_MEM_BYTE) ||
-                (opcodes[0]==Opcode.PUSH_MEM_B && opcodes[2]==Opcode.POP_MEM_BYTE) ||
-                (opcodes[0]==Opcode.PUSH_MEM_UW && opcodes[2]==Opcode.POP_MEM_WORD) ||
-                (opcodes[0]==Opcode.PUSH_MEM_W && opcodes[2]==Opcode.POP_MEM_WORD) ||
-                (opcodes[0]==Opcode.PUSH_MEM_FLOAT && opcodes[2]==Opcode.POP_MEM_FLOAT)) {
-            if(segment[0].arg==segment[2].arg) {
-                val fragment = sameMemOperation(segment[0].arg!!.integerValue(), segment[1])
-                if(fragment!=null) {
-                    fragment.segmentSize = 3
-                    result.add(fragment)
-                }
-            }
-        }
-        else if((opcodes[0]==Opcode.PUSH_BYTE && opcodes[1]==Opcode.READ_INDEXED_VAR_BYTE &&
-                        opcodes[3]==Opcode.PUSH_BYTE && opcodes[4]==Opcode.WRITE_INDEXED_VAR_BYTE) ||
-                (opcodes[0]==Opcode.PUSH_BYTE && opcodes[1]==Opcode.READ_INDEXED_VAR_WORD &&
-                        opcodes[3]==Opcode.PUSH_BYTE && opcodes[4]==Opcode.WRITE_INDEXED_VAR_WORD)) {
-            if(segment[0].arg==segment[3].arg && segment[1].callLabel==segment[4].callLabel) {
-                val fragment = sameConstantIndexedVarOperation(segment[1].callLabel!!, segment[0].arg!!.integerValue(), segment[2])
-                if(fragment!=null){
-                    fragment.segmentSize = 5
-                    result.add(fragment)
-                }
-            }
-        }
-        else if((opcodes[0]==Opcode.PUSH_VAR_BYTE && opcodes[1]==Opcode.READ_INDEXED_VAR_BYTE &&
-                        opcodes[3]==Opcode.PUSH_VAR_BYTE && opcodes[4]==Opcode.WRITE_INDEXED_VAR_BYTE) ||
-                (opcodes[0]==Opcode.PUSH_VAR_BYTE && opcodes[1]==Opcode.READ_INDEXED_VAR_WORD &&
-                        opcodes[3]==Opcode.PUSH_VAR_BYTE && opcodes[4]==Opcode.WRITE_INDEXED_VAR_WORD)) {
-            if(segment[0].callLabel==segment[3].callLabel && segment[1].callLabel==segment[4].callLabel) {
-                val fragment = sameIndexedVarOperation(segment[1].callLabel!!, segment[0].callLabel!!, segment[2])
-                if(fragment!=null){
-                    fragment.segmentSize = 5
-                    result.add(fragment)
-                }
-            }
-        }
-
-        // add any matching patterns from the big list
-        for(pattern in Patterns.patterns) {
-            if(pattern.sequence.size > segment.size || (pattern.altSequence!=null && pattern.altSequence.size > segment.size))
-                continue        //  don't accept patterns that don't fit
-            val opcodesList = opcodes.subList(0, pattern.sequence.size)
-            if(pattern.sequence == opcodesList) {
-                val asm = pattern.asm(segment)
-                if(asm!=null)
-                    result.add(AsmFragment(asm, pattern.sequence.size))
-            } else if(pattern.altSequence!=null) {
-                val opcodesListAlt = opcodes.subList(0, pattern.altSequence.size)
-                if(pattern.altSequence == opcodesListAlt) {
-                    val asm = pattern.asm(segment)
-                    if (asm != null)
-                        result.add(AsmFragment(asm, pattern.sequence.size))
-                }
-            }
-        }
-
-        return result
-    }
-
-    private fun sameConstantIndexedVarOperation(variable: String, index: Int, ins: Instruction): AsmFragment? {
-        // an in place operation that consists of a push-value / op / push-index-value / pop-into-indexed-var
-        return when(ins.opcode) {
-            Opcode.SHL_BYTE -> AsmFragment(" asl  $variable+$index", 8)
-            Opcode.SHR_UBYTE -> AsmFragment(" lsr  $variable+$index", 8)
-            Opcode.SHR_SBYTE -> AsmFragment(" lda  $variable+$index |  asl  a |  ror  $variable+$index")
-            Opcode.SHL_WORD -> AsmFragment(" asl  $variable+${index * 2 + 1} |  rol  $variable+${index * 2}", 8)
-            Opcode.SHR_UWORD -> AsmFragment(" lsr  $variable+${index * 2 + 1} |  ror  $variable+${index * 2}", 8)
-            Opcode.SHR_SWORD -> AsmFragment(" lda  $variable+${index * 2 + 1} |  asl  a |  ror  $variable+${index * 2 + 1} |  ror  $variable+${index * 2}", 8)
-            Opcode.ROL_BYTE -> AsmFragment(" rol  $variable+$index", 8)
-            Opcode.ROR_BYTE -> AsmFragment(" ror  $variable+$index", 8)
-            Opcode.ROL_WORD -> AsmFragment(" rol  $variable+${index * 2 + 1} |  rol  $variable+${index * 2}", 8)
-            Opcode.ROR_WORD -> AsmFragment(" ror  $variable+${index * 2 + 1} |  ror  $variable+${index * 2}", 8)
-            Opcode.ROL2_BYTE -> AsmFragment(" lda  $variable+$index |  cmp  #\$80 |  rol  $variable+$index", 8)
-            Opcode.ROR2_BYTE -> AsmFragment(" lda  $variable+$index |  lsr  a |  bcc  + |  ora  #\$80 |+ |  sta  $variable+$index", 10)
-            Opcode.ROL2_WORD -> AsmFragment(" asl  $variable+${index * 2 + 1} |  rol  $variable+${index * 2} |  bcc  + |  inc  $variable+${index * 2 + 1} |+", 20)
-            Opcode.ROR2_WORD -> AsmFragment(" lsr  $variable+${index * 2 + 1} |  ror  $variable+${index * 2} |  bcc  + |  lda  $variable+${index * 2 + 1} |  ora  #\$80 |  sta  $variable+${index * 2 + 1} |+", 30)
-            Opcode.INC_INDEXED_VAR_B, Opcode.INC_INDEXED_VAR_UB -> AsmFragment(" inc  $variable+$index", 2)
-            Opcode.DEC_INDEXED_VAR_B, Opcode.DEC_INDEXED_VAR_UB -> AsmFragment(" dec  $variable+$index", 5)
-            Opcode.INC_INDEXED_VAR_W, Opcode.INC_INDEXED_VAR_UW -> AsmFragment(" inc  $variable+${index * 2} |  bne  + |  inc  $variable+${index * 2 + 1} |+")
-            Opcode.DEC_INDEXED_VAR_W, Opcode.DEC_INDEXED_VAR_UW -> AsmFragment(" lda  $variable+${index * 2} |  bne  + |  dec  $variable+${index * 2 + 1} |+ |  dec  $variable+${index * 2}")
-            Opcode.INC_INDEXED_VAR_FLOAT -> AsmFragment(
-                    """
-                lda  #<($variable+${index * MachineDefinition.Mflpt5.MemorySize})
-                ldy  #>($variable+${index * MachineDefinition.Mflpt5.MemorySize})
-                jsr  c64flt.inc_var_f
-                """)
-            Opcode.DEC_INDEXED_VAR_FLOAT -> AsmFragment(
-                    """
-                lda  #<($variable+${index * MachineDefinition.Mflpt5.MemorySize})
-                ldy  #>($variable+${index * MachineDefinition.Mflpt5.MemorySize})
-                jsr  c64flt.dec_var_f
-                """)
-
-            else -> null
-        }
-    }
-
-    private fun sameIndexedVarOperation(variable: String, indexVar: String, ins: Instruction): AsmFragment? {
-        // an in place operation that consists of a push-value / op / push-index-var / pop-into-indexed-var
-        val saveX = " stx  ${MachineDefinition.C64Zeropage.SCRATCH_B1} |"
-        val restoreX = " | ldx  ${MachineDefinition.C64Zeropage.SCRATCH_B1}"
-        val loadXWord: String
-        val loadX: String
-
-        when(indexVar) {
-            "X" -> {
-                loadX = ""
-                loadXWord = " txa |  asl  a |  tax |"
-            }
-            "Y" -> {
-                loadX = " tya |  tax |"
-                loadXWord = " tya |  asl  a |  tax |"
-            }
-            "A" -> {
-                loadX = " tax |"
-                loadXWord = " asl  a |  tax |"
-            }
-            else -> {
-                // the indexvar is a real variable, not a register
-                loadX = " ldx  $indexVar |"
-                loadXWord = " lda  $indexVar |  asl  a |  tax |"
-            }
-        }
-
-        return when (ins.opcode) {
-            Opcode.SHL_BYTE -> AsmFragment(" txa |  $loadX  asl  $variable,x |  tax", 10)
-            Opcode.SHR_UBYTE -> AsmFragment(" txa |  $loadX  lsr  $variable,x |  tax", 10)
-            Opcode.SHR_SBYTE -> AsmFragment("$saveX  $loadX  lda  $variable,x |  asl a |  ror  $variable,x  $restoreX", 10)
-            Opcode.SHL_WORD -> AsmFragment("$saveX $loadXWord  asl  $variable,x |  rol  $variable+1,x  $restoreX", 10)
-            Opcode.SHR_UWORD -> AsmFragment("$saveX $loadXWord  lsr  $variable+1,x |  ror  $variable,x  $restoreX", 10)
-            Opcode.SHR_SWORD -> AsmFragment("$saveX $loadXWord  lda  $variable+1,x |  asl a |  ror  $variable+1,x |  ror  $variable,x  $restoreX", 10)
-            Opcode.ROL_BYTE -> AsmFragment(" txa |  $loadX  rol  $variable,x |  tax", 10)
-            Opcode.ROR_BYTE -> AsmFragment(" txa |  $loadX  ror  $variable,x |  tax", 10)
-            Opcode.ROL_WORD -> AsmFragment("$saveX $loadXWord  rol  $variable,x |  rol  $variable+1,x  $restoreX", 10)
-            Opcode.ROR_WORD -> AsmFragment("$saveX $loadXWord  ror  $variable+1,x |  ror  $variable,x  $restoreX", 10)
-            Opcode.ROL2_BYTE -> AsmFragment("$saveX $loadX  lda  $variable,x |  cmp  #\$80 |  rol  $variable,x  $restoreX", 10)
-            Opcode.ROR2_BYTE -> AsmFragment("$saveX $loadX  lda  $variable,x |  lsr  a |  bcc  + |  ora  #\$80 |+ |  sta  $variable,x  $restoreX", 10)
-            Opcode.ROL2_WORD -> AsmFragment(" txa |  $loadXWord  asl  $variable,x |  rol  $variable+1,x |  bcc  + |  inc  $variable,x  |+  |  tax", 30)
-            Opcode.ROR2_WORD -> AsmFragment("$saveX $loadXWord  lsr  $variable+1,x |  ror  $variable,x |  bcc  + |  lda  $variable+1,x |  ora  #\$80 |  sta  $variable+1,x |+  $restoreX", 30)
-            Opcode.INC_INDEXED_VAR_B, Opcode.INC_INDEXED_VAR_UB -> AsmFragment(" txa |  $loadX  inc  $variable,x |  tax", 10)
-            Opcode.DEC_INDEXED_VAR_B, Opcode.DEC_INDEXED_VAR_UB -> AsmFragment(" txa |  $loadX  dec  $variable,x |  tax", 10)
-            Opcode.INC_INDEXED_VAR_W, Opcode.INC_INDEXED_VAR_UW -> AsmFragment("$saveX $loadXWord  inc  $variable,x |  bne  + |  inc  $variable+1,x  |+  $restoreX", 10)
-            Opcode.DEC_INDEXED_VAR_W, Opcode.DEC_INDEXED_VAR_UW -> AsmFragment("$saveX $loadXWord  lda  $variable,x |  bne  + |  dec  $variable+1,x |+ |  dec  $variable,x  $restoreX", 10)
-            Opcode.INC_INDEXED_VAR_FLOAT -> AsmFragment(" lda  #<$variable |  ldy  #>$variable |  $saveX   $loadX   jsr  c64flt.inc_indexed_var_f  $restoreX")
-            Opcode.DEC_INDEXED_VAR_FLOAT -> AsmFragment(" lda  #<$variable |  ldy  #>$variable |  $saveX   $loadX   jsr  c64flt.dec_indexed_var_f  $restoreX")
-
-            else -> null
-        }
-    }
-
-    private fun sameMemOperation(address: Int, ins: Instruction): AsmFragment? {
-        // an in place operation that consists of  push-mem / op / pop-mem
-        val addr = address.toHex()
-        val addrHi = (address+1).toHex()
-        return when(ins.opcode) {
-            Opcode.SHL_BYTE -> AsmFragment(" asl  $addr", 10)
-            Opcode.SHR_UBYTE -> AsmFragment(" lsr  $addr", 10)
-            Opcode.SHR_SBYTE -> AsmFragment(" lda  $addr |  asl  a |  ror  $addr", 10)
-            Opcode.SHL_WORD -> AsmFragment(" asl  $addr |  rol  $addrHi", 10)
-            Opcode.SHR_UWORD -> AsmFragment(" lsr  $addrHi |  ror  $addr", 10)
-            Opcode.SHR_SWORD -> AsmFragment(" lda  $addrHi |  asl a |  ror  $addrHi |  ror  $addr", 10)
-            Opcode.ROL_BYTE -> AsmFragment(" rol  $addr", 10)
-            Opcode.ROR_BYTE -> AsmFragment(" ror  $addr", 10)
-            Opcode.ROL_WORD -> AsmFragment(" rol  $addr |  rol  $addrHi", 10)
-            Opcode.ROR_WORD -> AsmFragment(" ror  $addrHi |  ror  $addr", 10)
-            Opcode.ROL2_BYTE -> AsmFragment(" lda  $addr |  cmp  #\$80 |  rol  $addr", 10)
-            Opcode.ROR2_BYTE -> AsmFragment(" lda  $addr |  lsr  a |  bcc  + |  ora  #\$80 |+ |  sta  $addr", 10)
-            Opcode.ROL2_WORD -> AsmFragment(" lda  $addr |  cmp #\$80 |  rol  $addr |  rol  $addrHi", 10)
-            Opcode.ROR2_WORD -> AsmFragment(" lsr  $addrHi |  ror  $addr |  bcc  + |  lda  $addrHi |  ora  #$80 |  sta  $addrHi |+", 20)
-            else -> null
-        }
-    }
-
-    private fun sameVarOperation(variable: String, ins: Instruction): AsmFragment? {
-        // an in place operation that consists of a push-var / op / pop-var
-        return when(ins.opcode) {
-            Opcode.SHL_BYTE -> {
-                when (variable) {
-                    "A" -> AsmFragment(" asl  a", 10)
-                    "X" -> AsmFragment(" txa |  asl  a |  tax", 10)
-                    "Y" -> AsmFragment(" tya |  asl  a |  tay", 10)
-                    else -> AsmFragment(" asl  $variable", 10)
-                }
-            }
-            Opcode.SHR_UBYTE -> {
-                when (variable) {
-                    "A" -> AsmFragment(" lsr  a", 10)
-                    "X" -> AsmFragment(" txa |  lsr  a |  tax", 10)
-                    "Y" -> AsmFragment(" tya |  lsr  a |  tay", 10)
-                    else -> AsmFragment(" lsr  $variable", 10)
-                }
-            }
-            Opcode.SHR_SBYTE -> {
-                // arithmetic shift right (keep sign bit)
-                when (variable) {
-                    "A" -> AsmFragment(" cmp  #$80 |  ror  a", 10)
-                    "X" -> AsmFragment(" txa |  cmp  #$80 |  ror  a |  tax", 10)
-                    "Y" -> AsmFragment(" tya |  cmp  #$80 |  ror  a |  tay", 10)
-                    else -> AsmFragment(" lda  $variable |  asl  a  | ror  $variable", 10)
-                }
-            }
-            Opcode.SHL_WORD -> {
-                AsmFragment(" asl  $variable |  rol  $variable+1", 10)
-            }
-            Opcode.SHR_UWORD -> {
-                AsmFragment(" lsr  $variable+1 |  ror  $variable", 10)
-            }
-            Opcode.SHR_SWORD -> {
-                // arithmetic shift right (keep sign bit)
-                AsmFragment(" lda  $variable+1 |  asl  a |  ror  $variable+1 |  ror  $variable", 10)
-            }
-            Opcode.ROL_BYTE -> {
-                when (variable) {
-                    "A" -> AsmFragment(" rol  a", 10)
-                    "X" -> AsmFragment(" txa |  rol  a |  tax", 10)
-                    "Y" -> AsmFragment(" tya |  rol  a |  tay", 10)
-                    else -> AsmFragment(" rol  $variable", 10)
-                }
-            }
-            Opcode.ROR_BYTE -> {
-                when (variable) {
-                    "A" -> AsmFragment(" ror  a", 10)
-                    "X" -> AsmFragment(" txa |  ror  a |  tax", 10)
-                    "Y" -> AsmFragment(" tya |  ror  a |  tay", 10)
-                    else -> AsmFragment(" ror  $variable", 10)
-                }
-            }
-            Opcode.ROL_WORD -> {
-                AsmFragment(" rol  $variable |  rol  $variable+1", 10)
-            }
-            Opcode.ROR_WORD -> {
-                AsmFragment(" ror  $variable+1 |  ror  $variable", 10)
-            }
-            Opcode.ROL2_BYTE -> {       // 8-bit rol
-                when (variable) {
-                    "A" -> AsmFragment(" cmp  #\$80 |  rol  a", 10)
-                    "X" -> AsmFragment(" txa |  cmp  #\$80 |  rol  a |  tax", 10)
-                    "Y" -> AsmFragment(" tya |  cmp  #\$80 |  rol  a |  tay", 10)
-                    else -> AsmFragment(" lda  $variable |  cmp  #\$80  | rol  $variable", 10)
-                }
-            }
-            Opcode.ROR2_BYTE -> {       // 8-bit ror
-                when (variable) {
-                    "A" -> AsmFragment(" lsr  a | bcc  + |  ora  #\$80  |+", 10)
-                    "X" -> AsmFragment(" txa |  lsr  a |  bcc  + |  ora  #\$80  |+ |  tax", 10)
-                    "Y" -> AsmFragment(" tya |  lsr  a |  bcc  + |  ora  #\$80  |+ |  tay", 10)
-                    else -> AsmFragment(" lda  $variable |  lsr  a |  bcc  + |  ora  #\$80 |+ |  sta  $variable", 10)
-                }
-            }
-            Opcode.ROL2_WORD -> {
-                AsmFragment(" lda  $variable |  cmp #\$80 |  rol  $variable |  rol  $variable+1", 10)
-            }
-            Opcode.ROR2_WORD -> {
-                AsmFragment(" lsr  $variable+1 |  ror  $variable |  bcc  + |  lda  $variable+1 |  ora  #\$80 |  sta  $variable+1 |+", 30)
-            }
-            else -> null
-        }
-    }
-
-    private class AsmFragment(val asm: String, var segmentSize: Int=0)
-}

OldCodeGen/src/oldcodegen/SimpleAsm.kt

@@ -1,562 +0,0 @@
-package oldcodegen
-
-/** OLD STACK-VM CODE GEN -- NO LONGER USED **/
-
-
-import prog8.compiler.CompilerException
-import prog8.compiler.intermediate.Instruction
-import prog8.compiler.intermediate.IntermediateProgram
-import prog8.compiler.intermediate.LabelInstr
-import prog8.compiler.intermediate.Opcode
-import prog8.compiler.target.c64.MachineDefinition.C64Zeropage
-import prog8.compiler.target.c64.MachineDefinition.ESTACK_HI_HEX
-import prog8.compiler.target.c64.MachineDefinition.ESTACK_HI_PLUS1_HEX
-import prog8.compiler.target.c64.MachineDefinition.ESTACK_LO_HEX
-import prog8.compiler.target.c64.MachineDefinition.ESTACK_LO_PLUS1_HEX
-import prog8.compiler.target.c64.MachineDefinition.ESTACK_LO_PLUS2_HEX
-import prog8.compiler.toHex
-import prog8.vm.stackvm.Syscall
-import prog8.vm.stackvm.syscallsForStackVm
-
-
-// note: see https://wiki.nesdev.com/w/index.php/6502_assembly_optimisations
-
-
-private var breakpointCounter = 0
-
-internal fun simpleInstr2Asm(ins: Instruction, block: IntermediateProgram.ProgramBlock): String? {
-    // a label 'instruction' is simply translated into a asm label
-    if(ins is LabelInstr) {
-        val labelresult =
-                if(ins.name.startsWith("${block.name}."))
-                    ins.name.substring(block.name.length+1)
-                else
-                    ins.name
-        return if(ins.asmProc) labelresult+"\t\t.proc" else labelresult
-    }
-
-    // simple opcodes that are translated directly into one or a few asm instructions
-    return when(ins.opcode) {
-        Opcode.LINE -> " ;\tsrc line: ${ins.callLabel}"
-        Opcode.NOP -> " nop"      // shouldn't be present anymore though
-        Opcode.START_PROCDEF -> ""  // is done as part of a label
-        Opcode.END_PROCDEF -> " .pend"
-        Opcode.TERMINATE -> " brk"
-        Opcode.SEC -> " sec"
-        Opcode.CLC -> " clc"
-        Opcode.SEI -> " sei"
-        Opcode.CLI -> " cli"
-        Opcode.CARRY_TO_A -> " lda  #0 |  adc  #0"
-        Opcode.JUMP -> {
-            if(ins.callLabel!=null)
-                " jmp  ${ins.callLabel}"
-            else
-                " jmp  ${hexVal(ins)}"
-        }
-        Opcode.CALL -> {
-            if(ins.callLabel!=null)
-                " jsr  ${ins.callLabel}"
-            else
-                " jsr  ${hexVal(ins)}"
-        }
-        Opcode.RETURN -> " rts"
-        Opcode.RSAVE -> {
-            // save cpu status flag and all registers A, X, Y.
-            // see http://6502.org/tutorials/register_preservation.html
-            " php |  sta  ${C64Zeropage.SCRATCH_REG} | pha  | txa  | pha  | tya  | pha  | lda  ${C64Zeropage.SCRATCH_REG}"
-        }
-        Opcode.RRESTORE -> {
-            // restore all registers and cpu status flag
-            " pla |  tay |  pla |  tax |  pla |  plp"
-        }
-        Opcode.RSAVEX -> " sta  ${C64Zeropage.SCRATCH_REG} |  txa |  pha |  lda  ${C64Zeropage.SCRATCH_REG}"
-        Opcode.RRESTOREX -> " sta  ${C64Zeropage.SCRATCH_REG} |  pla |  tax |  lda  ${C64Zeropage.SCRATCH_REG}"
-        Opcode.DISCARD_BYTE -> " inx"
-        Opcode.DISCARD_WORD -> " inx"
-        Opcode.DISCARD_FLOAT -> " inx |  inx |  inx"
-        Opcode.DUP_B -> {
-            " lda $ESTACK_LO_PLUS1_HEX,x | sta $ESTACK_LO_HEX,x | dex | ;DUP_B "
-        }
-        Opcode.DUP_W -> {
-            " lda $ESTACK_LO_PLUS1_HEX,x | sta $ESTACK_LO_HEX,x | lda $ESTACK_HI_PLUS1_HEX,x | sta $ESTACK_HI_HEX,x | dex "
-        }
-
-        Opcode.CMP_B, Opcode.CMP_UB -> {
-            " inx | lda $ESTACK_LO_HEX,x | cmp #${ins.arg!!.integerValue().toHex()} | ;CMP_B "
-        }
-
-        Opcode.CMP_W, Opcode.CMP_UW -> {
-            """
-            inx
-            lda   $ESTACK_HI_HEX,x
-            cmp   #>${ins.arg!!.integerValue().toHex()}
-            bne   +
-            lda   $ESTACK_LO_HEX,x
-            cmp   #<${ins.arg.integerValue().toHex()}
-            ; bne   +    not necessary?
-            ; lda   #0   not necessary?
-+                           
-            """
-        }
-
-        Opcode.INLINE_ASSEMBLY ->  "@inline@" + (ins.callLabel2 ?: "")      // All of the inline assembly is stored in the calllabel2 property. the '@inline@' is a special marker to accept it.
-        Opcode.INCLUDE_FILE -> {
-            val offset = if(ins.arg==null) "" else ", ${ins.arg.integerValue()}"
-            val length = if(ins.arg2==null) "" else ", ${ins.arg2.integerValue()}"
-            " .binary  \"${ins.callLabel}\" $offset $length"
-        }
-        Opcode.SYSCALL -> {
-            if (ins.arg!!.numericValue() in syscallsForStackVm.map { it.callNr })
-                throw CompilerException("cannot translate vm syscalls to real assembly calls - use *real* subroutine calls instead. Syscall ${ins.arg.numericValue()}")
-            val call = Syscall.values().find { it.callNr==ins.arg.numericValue() }
-            when(call) {
-                Syscall.FUNC_SIN,
-                Syscall.FUNC_COS,
-                Syscall.FUNC_ABS,
-                Syscall.FUNC_TAN,
-                Syscall.FUNC_ATAN,
-                Syscall.FUNC_LN,
-                Syscall.FUNC_LOG2,
-                Syscall.FUNC_SQRT,
-                Syscall.FUNC_RAD,
-                Syscall.FUNC_DEG,
-                Syscall.FUNC_ROUND,
-                Syscall.FUNC_FLOOR,
-                Syscall.FUNC_CEIL,
-                Syscall.FUNC_RNDF,
-                Syscall.FUNC_ANY_F,
-                Syscall.FUNC_ALL_F,
-                Syscall.FUNC_MAX_F,
-                Syscall.FUNC_MIN_F,
-                Syscall.FUNC_SUM_F -> " jsr  c64flt.${call.name.toLowerCase()}"
-                null -> ""
-                else -> " jsr  prog8_lib.${call.name.toLowerCase()}"
-            }
-        }
-        Opcode.BREAKPOINT -> {
-            breakpointCounter++
-            "_prog8_breakpoint_$breakpointCounter\tnop"
-        }
-
-        Opcode.PUSH_BYTE -> {
-            " lda  #${hexVal(ins)} |  sta  $ESTACK_LO_HEX,x |  dex"
-        }
-        Opcode.PUSH_WORD -> {
-            val value = hexVal(ins)
-            " lda  #<$value |  sta  $ESTACK_LO_HEX,x |  lda  #>$value |  sta  $ESTACK_HI_HEX,x |  dex"
-        }
-        Opcode.PUSH_FLOAT -> {
-            val floatConst = getFloatConst(ins.arg!!)
-            " lda  #<$floatConst |  ldy  #>$floatConst |  jsr  c64flt.push_float"
-        }
-        Opcode.PUSH_VAR_BYTE -> {
-            when(ins.callLabel) {
-                "X" -> throw CompilerException("makes no sense to push X, it's used as a stack pointer itself. You should probably not use the X register (or only in trivial assignments)")
-                "A" -> " sta  $ESTACK_LO_HEX,x |  dex"
-                "Y" -> " tya |  sta  $ESTACK_LO_HEX,x |  dex"
-                else -> " lda  ${ins.callLabel} |  sta  $ESTACK_LO_HEX,x |  dex"
-            }
-        }
-        Opcode.PUSH_VAR_WORD -> {
-            " lda  ${ins.callLabel} |  sta  $ESTACK_LO_HEX,x |  lda  ${ins.callLabel}+1 |    sta  $ESTACK_HI_HEX,x |  dex"
-        }
-        Opcode.PUSH_VAR_FLOAT -> " lda  #<${ins.callLabel} |  ldy  #>${ins.callLabel}|  jsr  c64flt.push_float"
-        Opcode.PUSH_MEM_B, Opcode.PUSH_MEM_UB -> {
-            """
-                lda  ${hexVal(ins)}
-                sta  $ESTACK_LO_HEX,x
-                dex
-                """
-        }
-        Opcode.PUSH_MEM_W, Opcode.PUSH_MEM_UW -> {
-            """
-                lda  ${hexVal(ins)}
-                sta  $ESTACK_LO_HEX,x
-                lda  ${hexValPlusOne(ins)}
-                sta  $ESTACK_HI_HEX,x
-                dex
-                """
-        }
-        Opcode.PUSH_MEM_FLOAT -> {
-            " lda  #<${hexVal(ins)} |  ldy  #>${hexVal(ins)}|  jsr  c64flt.push_float"
-        }
-        Opcode.PUSH_MEMREAD -> {
-            """
-                lda  $ESTACK_LO_PLUS1_HEX,x
-                sta  (+) +1
-                lda  $ESTACK_HI_PLUS1_HEX,x
-                sta  (+) +2
-+               lda  65535    ; modified
-                sta  $ESTACK_LO_PLUS1_HEX,x
-                """
-        }
-
-        Opcode.PUSH_REGAY_WORD -> {
-            " sta  $ESTACK_LO_HEX,x |  tya |  sta  $ESTACK_HI_HEX,x |  dex "
-        }
-        Opcode.PUSH_ADDR_HEAPVAR -> {
-            " lda  #<${ins.callLabel} |  sta  $ESTACK_LO_HEX,x |  lda  #>${ins.callLabel}  |  sta  $ESTACK_HI_HEX,x |  dex"
-        }
-        Opcode.POP_REGAX_WORD -> throw AssemblyError("cannot load X register from stack because it's used as the stack pointer itself")
-        Opcode.POP_REGXY_WORD -> throw AssemblyError("cannot load X register from stack because it's used as the stack pointer itself")
-        Opcode.POP_REGAY_WORD -> {
-            " inx |  lda  $ESTACK_LO_HEX,x |  ldy  $ESTACK_HI_HEX,x "
-        }
-
-        Opcode.READ_INDEXED_VAR_BYTE -> {
-            """
-                ldy  $ESTACK_LO_PLUS1_HEX,x
-                lda  ${ins.callLabel},y
-                sta  $ESTACK_LO_PLUS1_HEX,x
-                """
-        }
-        Opcode.READ_INDEXED_VAR_WORD -> {
-            """
-                lda  $ESTACK_LO_PLUS1_HEX,x
-                asl  a
-                tay
-                lda  ${ins.callLabel},y
-                sta  $ESTACK_LO_PLUS1_HEX,x
-                lda  ${ins.callLabel}+1,y
-                sta  $ESTACK_HI_PLUS1_HEX,x
-                """
-        }
-        Opcode.READ_INDEXED_VAR_FLOAT -> {
-            """
-                lda  #<${ins.callLabel}
-                ldy  #>${ins.callLabel}
-                jsr  c64flt.push_float_from_indexed_var
-                """
-        }
-        Opcode.WRITE_INDEXED_VAR_BYTE -> {
-            """
-                inx
-                ldy  $ESTACK_LO_HEX,x
-                inx
-                lda  $ESTACK_LO_HEX,x
-                sta  ${ins.callLabel},y
-                """
-        }
-        Opcode.WRITE_INDEXED_VAR_WORD -> {
-            """
-                inx
-                lda  $ESTACK_LO_HEX,x
-                asl  a
-                tay
-                inx
-                lda  $ESTACK_LO_HEX,x
-                sta  ${ins.callLabel},y
-                lda  $ESTACK_HI_HEX,x
-                sta  ${ins.callLabel}+1,y
-                """
-        }
-        Opcode.WRITE_INDEXED_VAR_FLOAT -> {
-            """
-                lda  #<${ins.callLabel}
-                ldy  #>${ins.callLabel}
-                jsr  c64flt.pop_float_to_indexed_var
-                """
-        }
-        Opcode.POP_MEM_BYTE -> {
-            """
-                inx
-                lda  $ESTACK_LO_HEX,x
-                sta  ${hexVal(ins)}
-                """
-        }
-        Opcode.POP_MEM_WORD -> {
-            """
-                inx
-                lda  $ESTACK_LO_HEX,x
-                sta  ${hexVal(ins)}
-                lda  $ESTACK_HI_HEX,x
-                sta  ${hexValPlusOne(ins)}
-                """
-        }
-        Opcode.POP_MEM_FLOAT -> {
-            " lda  ${hexVal(ins)} |  ldy  ${hexValPlusOne(ins)} |  jsr  c64flt.pop_float"
-        }
-        Opcode.POP_MEMWRITE -> {
-            """
-                inx
-                lda  $ESTACK_LO_HEX,x
-                sta  (+) +1
-                lda  $ESTACK_HI_HEX,x
-                sta  (+) +2
-                inx
-                lda  $ESTACK_LO_HEX,x
-+               sta  65535       ; modified
-                """
-        }
-
-        Opcode.POP_VAR_BYTE -> {
-            when (ins.callLabel) {
-                "X" -> throw CompilerException("makes no sense to pop X, it's used as a stack pointer itself")
-                "A" -> " inx |  lda  $ESTACK_LO_HEX,x"
-                "Y" -> " inx |  ldy  $ESTACK_LO_HEX,x"
-                else -> " inx |  lda  $ESTACK_LO_HEX,x |  sta  ${ins.callLabel}"
-            }
-        }
-        Opcode.POP_VAR_WORD -> {
-            " inx |  lda  $ESTACK_LO_HEX,x |  ldy  $ESTACK_HI_HEX,x |  sta  ${ins.callLabel} |  sty  ${ins.callLabel}+1"
-        }
-        Opcode.POP_VAR_FLOAT -> {
-            " lda  #<${ins.callLabel} |  ldy  #>${ins.callLabel} |  jsr  c64flt.pop_float"
-        }
-
-        Opcode.INC_VAR_UB, Opcode.INC_VAR_B -> {
-            when (ins.callLabel) {
-                "A" -> " clc |  adc  #1"
-                "X" -> " inx"
-                "Y" -> " iny"
-                else -> " inc  ${ins.callLabel}"
-            }
-        }
-        Opcode.INC_VAR_UW, Opcode.INC_VAR_W -> {
-            " inc  ${ins.callLabel} |  bne  + |  inc  ${ins.callLabel}+1 |+"
-        }
-        Opcode.INC_VAR_F -> {
-            """
-                lda  #<${ins.callLabel}
-                ldy  #>${ins.callLabel}
-                jsr  c64flt.inc_var_f
-                """
-        }
-        Opcode.POP_INC_MEMORY -> {
-            """
-                inx
-                lda  $ESTACK_LO_HEX,x
-                sta  (+) +1
-                lda  $ESTACK_HI_HEX,x
-                sta  (+) +2
-+               inc  65535     ; modified
-                """
-        }
-        Opcode.POP_DEC_MEMORY -> {
-            """
-                inx
-                lda  $ESTACK_LO_HEX,x
-                sta  (+) +1
-                lda  $ESTACK_HI_HEX,x
-                sta  (+) +2
-+               dec  65535     ; modified
-                """
-        }
-        Opcode.DEC_VAR_UB, Opcode.DEC_VAR_B -> {
-            when (ins.callLabel) {
-                "A" -> " sec |  sbc  #1"
-                "X" -> " dex"
-                "Y" -> " dey"
-                else -> " dec  ${ins.callLabel}"
-            }
-        }
-        Opcode.DEC_VAR_UW, Opcode.DEC_VAR_W -> {
-            " lda  ${ins.callLabel} |  bne  + |  dec  ${ins.callLabel}+1 |+ |  dec  ${ins.callLabel}"
-        }
-        Opcode.DEC_VAR_F -> {
-            """
-                lda  #<${ins.callLabel}
-                ldy  #>${ins.callLabel}
-                jsr  c64flt.dec_var_f
-                """
-        }
-        Opcode.INC_MEMORY -> " inc  ${hexVal(ins)}"
-        Opcode.DEC_MEMORY -> " dec  ${hexVal(ins)}"
-        Opcode.INC_INDEXED_VAR_B, Opcode.INC_INDEXED_VAR_UB -> " inx |  txa |  pha |  lda  $ESTACK_LO_HEX,x |  tax |  inc  ${ins.callLabel},x |  pla |  tax"
-        Opcode.DEC_INDEXED_VAR_B, Opcode.DEC_INDEXED_VAR_UB -> " inx |  txa |  pha |  lda  $ESTACK_LO_HEX,x |  tax |  dec  ${ins.callLabel},x |  pla |  tax"
-
-        Opcode.NEG_B -> " jsr  prog8_lib.neg_b"
-        Opcode.NEG_W -> " jsr  prog8_lib.neg_w"
-        Opcode.NEG_F -> " jsr  c64flt.neg_f"
-        Opcode.ABS_B -> " jsr  prog8_lib.abs_b"
-        Opcode.ABS_W -> " jsr  prog8_lib.abs_w"
-        Opcode.ABS_F -> " jsr  c64flt.abs_f"
-        Opcode.POW_F -> " jsr  c64flt.pow_f"
-        Opcode.INV_BYTE -> {
-            """
-                lda  $ESTACK_LO_PLUS1_HEX,x
-                eor  #255
-                sta  $ESTACK_LO_PLUS1_HEX,x
-                """
-        }
-        Opcode.INV_WORD -> " jsr  prog8_lib.inv_word"
-        Opcode.NOT_BYTE -> " jsr  prog8_lib.not_byte"
-        Opcode.NOT_WORD -> " jsr  prog8_lib.not_word"
-        Opcode.BCS -> {
-            val label = ins.callLabel ?: hexVal(ins)
-            " bcs  $label"
-        }
-        Opcode.BCC -> {
-            val label = ins.callLabel ?: hexVal(ins)
-            " bcc  $label"
-        }
-        Opcode.BNEG -> {
-            val label = ins.callLabel ?: hexVal(ins)
-            " bmi  $label"
-        }
-        Opcode.BPOS -> {
-            val label = ins.callLabel ?: hexVal(ins)
-            " bpl  $label"
-        }
-        Opcode.BVC -> {
-            val label = ins.callLabel ?: hexVal(ins)
-            " bvc  $label"
-        }
-        Opcode.BVS -> {
-            val label = ins.callLabel ?: hexVal(ins)
-            " bvs  $label"
-        }
-        Opcode.BZ -> {
-            val label = ins.callLabel ?: hexVal(ins)
-            " beq  $label"
-        }
-        Opcode.BNZ -> {
-            val label = ins.callLabel ?: hexVal(ins)
-            " bne  $label"
-        }
-        Opcode.JZ -> {
-            val label = ins.callLabel ?: hexVal(ins)
-            """
-                inx
-                lda  $ESTACK_LO_HEX,x
-                beq  $label
-                """
-        }
-        Opcode.JZW -> {
-            val label = ins.callLabel ?: hexVal(ins)
-            """
-                inx
-                lda  $ESTACK_LO_HEX,x
-                beq  $label
-                lda  $ESTACK_HI_HEX,x
-                beq  $label
-                """
-        }
-        Opcode.JNZ -> {
-            val label = ins.callLabel ?: hexVal(ins)
-            """
-                inx
-                lda  $ESTACK_LO_HEX,x
-                bne  $label
-                """
-        }
-        Opcode.JNZW -> {
-            val label = ins.callLabel ?: hexVal(ins)
-            """
-                inx
-                lda  $ESTACK_LO_HEX,x
-                bne  $label
-                lda  $ESTACK_HI_HEX,x
-                bne  $label
-                """
-        }
-        Opcode.CAST_B_TO_UB -> ""  // is a no-op, just carry on with the byte as-is
-        Opcode.CAST_UB_TO_B -> ""  // is a no-op, just carry on with the byte as-is
-        Opcode.CAST_W_TO_UW -> ""  // is a no-op, just carry on with the word as-is
-        Opcode.CAST_UW_TO_W -> ""  // is a no-op, just carry on with the word as-is
-        Opcode.CAST_W_TO_UB -> ""  // is a no-op, just carry on with the lsb of the word as-is
-        Opcode.CAST_W_TO_B -> ""  // is a no-op, just carry on with the lsb of the word as-is
-        Opcode.CAST_UW_TO_UB -> ""  // is a no-op, just carry on with the lsb of the uword as-is
-        Opcode.CAST_UW_TO_B -> ""  // is a no-op, just carry on with the lsb of the uword as-is
-        Opcode.CAST_UB_TO_F -> " jsr  c64flt.stack_ub2float"
-        Opcode.CAST_B_TO_F -> " jsr  c64flt.stack_b2float"
-        Opcode.CAST_UW_TO_F -> " jsr  c64flt.stack_uw2float"
-        Opcode.CAST_W_TO_F -> " jsr  c64flt.stack_w2float"
-        Opcode.CAST_F_TO_UB -> " jsr  c64flt.stack_float2ub"
-        Opcode.CAST_F_TO_B -> " jsr  c64flt.stack_float2b"
-        Opcode.CAST_F_TO_UW -> " jsr  c64flt.stack_float2uw"
-        Opcode.CAST_F_TO_W -> " jsr  c64flt.stack_float2w"
-        Opcode.CAST_UB_TO_UW, Opcode.CAST_UB_TO_W -> " lda  #0 |  sta  $ESTACK_HI_PLUS1_HEX,x"     // clear the msb
-        Opcode.CAST_B_TO_UW, Opcode.CAST_B_TO_W -> " lda  $ESTACK_LO_PLUS1_HEX,x |  ${signExtendA("$ESTACK_HI_PLUS1_HEX,x")}"     // sign extend the lsb
-        Opcode.MSB -> " lda  $ESTACK_HI_PLUS1_HEX,x |  sta  $ESTACK_LO_PLUS1_HEX,x"
-        Opcode.MKWORD -> " inx |  lda  $ESTACK_LO_HEX,x |  sta  $ESTACK_HI_PLUS1_HEX,x "
-
-        Opcode.ADD_UB, Opcode.ADD_B -> {        // TODO inline better (pattern with more opcodes)
-            """
-                lda  $ESTACK_LO_PLUS2_HEX,x
-                clc
-                adc  $ESTACK_LO_PLUS1_HEX,x
-                inx
-                sta  $ESTACK_LO_PLUS1_HEX,x
-                """
-        }
-        Opcode.SUB_UB, Opcode.SUB_B -> {        // TODO inline better (pattern with more opcodes)
-            """
-                lda  $ESTACK_LO_PLUS2_HEX,x
-                sec
-                sbc  $ESTACK_LO_PLUS1_HEX,x
-                inx
-                sta  $ESTACK_LO_PLUS1_HEX,x
-                """
-        }
-        Opcode.ADD_W, Opcode.ADD_UW -> "  jsr  prog8_lib.add_w"
-        Opcode.SUB_W, Opcode.SUB_UW -> "  jsr  prog8_lib.sub_w"
-        Opcode.MUL_B, Opcode.MUL_UB -> "  jsr  prog8_lib.mul_byte"
-        Opcode.MUL_W, Opcode.MUL_UW -> "  jsr  prog8_lib.mul_word"
-        Opcode.MUL_F -> "  jsr  c64flt.mul_f"
-        Opcode.ADD_F -> "  jsr  c64flt.add_f"
-        Opcode.SUB_F -> "  jsr  c64flt.sub_f"
-        Opcode.DIV_F -> "  jsr  c64flt.div_f"
-        Opcode.IDIV_UB -> "  jsr  prog8_lib.idiv_ub"
-        Opcode.IDIV_B -> "  jsr  prog8_lib.idiv_b"
-        Opcode.IDIV_W -> "  jsr  prog8_lib.idiv_w"
-        Opcode.IDIV_UW -> "  jsr  prog8_lib.idiv_uw"
-
-        Opcode.AND_BYTE -> "  jsr  prog8_lib.and_b"
-        Opcode.OR_BYTE -> "  jsr  prog8_lib.or_b"
-        Opcode.XOR_BYTE -> "  jsr  prog8_lib.xor_b"
-        Opcode.AND_WORD -> "  jsr  prog8_lib.and_w"
-        Opcode.OR_WORD -> "  jsr  prog8_lib.or_w"
-        Opcode.XOR_WORD -> "  jsr  prog8_lib.xor_w"
-
-        Opcode.BITAND_BYTE -> "  jsr  prog8_lib.bitand_b"
-        Opcode.BITOR_BYTE -> "  jsr  prog8_lib.bitor_b"
-        Opcode.BITXOR_BYTE -> "  jsr  prog8_lib.bitxor_b"
-        Opcode.BITAND_WORD -> "  jsr  prog8_lib.bitand_w"
-        Opcode.BITOR_WORD -> "  jsr  prog8_lib.bitor_w"
-        Opcode.BITXOR_WORD -> "  jsr  prog8_lib.bitxor_w"
-
-        Opcode.REMAINDER_UB -> "  jsr  prog8_lib.remainder_ub"
-        Opcode.REMAINDER_UW -> "  jsr  prog8_lib.remainder_uw"
-
-        Opcode.GREATER_B -> "  jsr  prog8_lib.greater_b"
-        Opcode.GREATER_UB -> "  jsr  prog8_lib.greater_ub"
-        Opcode.GREATER_W -> "  jsr  prog8_lib.greater_w"
-        Opcode.GREATER_UW -> "  jsr  prog8_lib.greater_uw"
-        Opcode.GREATER_F -> "  jsr  c64flt.greater_f"
-
-        Opcode.GREATEREQ_B -> "  jsr  prog8_lib.greatereq_b"
-        Opcode.GREATEREQ_UB -> "  jsr  prog8_lib.greatereq_ub"
-        Opcode.GREATEREQ_W -> "  jsr  prog8_lib.greatereq_w"
-        Opcode.GREATEREQ_UW -> "  jsr  prog8_lib.greatereq_uw"
-        Opcode.GREATEREQ_F -> "  jsr  c64flt.greatereq_f"
-
-        Opcode.EQUAL_BYTE -> "  jsr  prog8_lib.equal_b"
-        Opcode.EQUAL_WORD -> "  jsr  prog8_lib.equal_w"
-        Opcode.EQUAL_F -> "  jsr  c64flt.equal_f"
-        Opcode.NOTEQUAL_BYTE -> "  jsr prog8_lib.notequal_b"
-        Opcode.NOTEQUAL_WORD -> "  jsr prog8_lib.notequal_w"
-        Opcode.NOTEQUAL_F -> "  jsr  c64flt.notequal_f"
-
-        Opcode.LESS_UB -> "  jsr  prog8_lib.less_ub"
-        Opcode.LESS_B -> "  jsr  prog8_lib.less_b"
-        Opcode.LESS_UW -> "  jsr  prog8_lib.less_uw"
-        Opcode.LESS_W -> "  jsr  prog8_lib.less_w"
-        Opcode.LESS_F -> "  jsr  c64flt.less_f"
-
-        Opcode.LESSEQ_UB -> "  jsr  prog8_lib.lesseq_ub"
-        Opcode.LESSEQ_B -> "  jsr  prog8_lib.lesseq_b"
-        Opcode.LESSEQ_UW -> "  jsr  prog8_lib.lesseq_uw"
-        Opcode.LESSEQ_W -> "  jsr  prog8_lib.lesseq_w"
-        Opcode.LESSEQ_F -> "  jsr  c64flt.lesseq_f"
-
-        Opcode.SHIFTEDL_BYTE -> "  asl  $ESTACK_LO_PLUS1_HEX,x"
-        Opcode.SHIFTEDL_WORD -> "  asl  $ESTACK_LO_PLUS1_HEX,x |  rol  $ESTACK_HI_PLUS1_HEX,x"
-        Opcode.SHIFTEDR_SBYTE -> "  lda  $ESTACK_LO_PLUS1_HEX,x |  asl  a |  ror  $ESTACK_LO_PLUS1_HEX,x"
-        Opcode.SHIFTEDR_UBYTE -> "  lsr  $ESTACK_LO_PLUS1_HEX,x"
-        Opcode.SHIFTEDR_SWORD -> "  lda  $ESTACK_HI_PLUS1_HEX,x |  asl a  |  ror  $ESTACK_HI_PLUS1_HEX,x |  ror  $ESTACK_LO_PLUS1_HEX,x"
-        Opcode.SHIFTEDR_UWORD -> "  lsr  $ESTACK_HI_PLUS1_HEX,x |  ror  $ESTACK_LO_PLUS1_HEX,x"
-
-        else -> null
-    }
-}

README.md

@@ -1,64 +1,116 @@
-[![saythanks](https://img.shields.io/badge/say-thanks-ff69b4.svg)](https://saythanks.io/to/irmen)
-[![Build Status](https://travis-ci.org/irmen/prog8.svg?branch=master)](https://travis-ci.org/irmen/prog8)
+[![ko-fi](https://ko-fi.com/img/githubbutton_sm.svg)](https://ko-fi.com/H2H6S0FFF)
+[![Documentation](https://readthedocs.org/projects/prog8/badge/?version=latest)](https://prog8.readthedocs.io/)
 
-Prog8 - Structured Programming Language for 8-bit 6502/6510 microprocessors
-===========================================================================
+Prog8 - Structured Programming Language for 8-bit 6502/65c02 microprocessors
+============================================================================
 
 *Written by Irmen de Jong (irmen@razorvine.net)*
 
-*Software license: GNU GPL 3.0, see file LICENSE*
-
-
-This is a structured programming language for the 8-bit 6502/6510 microprocessor from the late 1970's and 1980's
+This is a structured programming language for the 8-bit 6502/6510/65c02 microprocessor from the late 1970's and 1980's
 as used in many home computers from that era. It is a medium to low level programming language,
-which aims to provide many conveniences over raw assembly code (even when using a macro assembler):
+which aims to provide many conveniences over raw assembly code (even when using a macro assembler).
 
-- reduction of source code length
+**Want to buy me a coffee or a pizza perhaps?**
+
+This project was created over the last couple of years by dedicating thousands of hours of my free time to it, to make it the best I possibly can.
+If you like Prog8, and think it's worth a nice cup of hot coffee or a delicious pizza, 
+you can help me out a little bit over at [ko-fi.com/irmen](https://ko-fi.com/irmen). 
+
+
+Documentation
+-------------
+Full documentation (syntax reference, how to use the language and the compiler, etc.) can be found at:
+https://prog8.readthedocs.io/
+
+How to get it/build it
+----------------------
+
+- Download the latest [official release](https://github.com/irmen/prog8/releases) from github.
+- Or, if you want/need a bleeding edge development version, you can:
+  - download a build artifact zipfile from a recent [github action build](https://github.com/irmen/prog8/actions).
+  - you can also compile it yourself from source. [Instructions here](https://prog8.readthedocs.io/en/latest/compiling.html).
+- Alternatively, you can also install the compiler as a package on some linux distros:
+  - Arch (via AUR): [`prog8`](https://aur.archlinux.org/packages/prog8)
+
+Community
+---------
+Most of the development on Prog8 and the use of it is currently centered around 
+the [Commander X16](https://www.commanderx16.com/) retro computer. Their [discord server](https://discord.gg/nS2PqEC) contains a small channel
+dedicated to Prog8. Other than that, use the issue tracker on github.
+
+
+Software license
+----------------
+GNU GPL 3.0 (see file LICENSE), with exception for generated code:
+
+- The compiler and its libraries are free to use according to the terms of the GNU GPL 3.0
+- *exception:* the resulting files (intermediate source codes and resulting binary program) created by the compiler
+  are excluded from the GPL and are free to use in whatever way desired, commercially or not.
+
+
+What does Prog8 provide?
+------------------------
+
+- all advantages of a higher level language over having to write assembly code manually
+- programs run very fast because compilation to native machine code
+- code often is smaller and faster than equivalent C code compiled with CC65 or even LLVM-MOS
 - modularity, symbol scoping, subroutines
 - 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
+- floating point math is supported if the target system provides floating point library routines (C64 and Cx16 both do)
+- strings can contain escaped characters but also many symbols directly if they have a petscii equivalent, such as "♠♥♣♦π▚●○╳". Characters like ^, _, \, {, } and | are also accepted and converted to the closest petscii equivalents.
+- automatic static variable allocations, automatic string and array variables and string sharing
+- subroutines with input parameters and result values
+- high-level program optimizations
+- no need for forward declarations
+- small program boilerplate/compilersupport overhead
+- programs can be run multiple times without reloading because of automatic variable (re)initializations.
 - conditional branches
-- '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...)
+- ``when`` statement to provide a concise jump table alternative to if/elseif chains
+- ``in`` expression for concise and efficient multi-value/containment check 
+- several specialized built-in functions such as ``lsb``, ``msb``, ``min``, ``max``, ``rol``, ``ror``
+- various powerful built-in libraries to do I/O, number conversions, graphics and more  
+- convenience abstractions for low level aspects such as ZeroPage handling, program startup, explicit memory addresses
 - 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``
+- supports the sixteen 'virtual' 16-bit registers R0 - R15 from the Commander X16, and provides them also on the C64.
+- encode strings and characters into petscii or screencodes or even other encodings, as desired (C64/Cx16)
 
-Rapid edit-compile-run-debug cycle:
+*Rapid edit-compile-run-debug cycle:*
 
-- use modern PC to work on 
-- quick compilation times (seconds)
-- option to automatically run the program in the Vice emulator  
+- use a modern PC to do the work on, use nice editors and enjoy quick compilation times
+- can automatically run the program in the Vice emulator after succesful compilation
 - 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.
+*Multiple supported compiler targets* (contributions to improve these or to add support for other machines are welcome!):
 
-Documentation/manual
---------------------
-See https://prog8.readthedocs.io/
+- "c64": Commodore-64  (6502 like CPU)
+- "c128": Commodore-128  (6502 like CPU - the Z80 cpu mode is not supported)
+- "cx16": [CommanderX16](https://www.commanderx16.com)  (65c02 CPU)
+- "pet32": Commodore PET (experimental)
+- "atari": Atari 8 bit such as 800XL (experimental)
+- If you only use standard kernal and prog8 library routines, it is possible to compile the *exact same program* for different machines (just change the compiler target flag)
 
 
-Required tools
---------------
+
+Additional 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.
 For other platforms it is very easy to compile it yourself (make ; make install).
 
-A **Java runtime (jre or jdk), version 8 or newer**  is required to run a prepackaged version of the compiler.
+A **Java runtime (jre or jdk), version 11 or newer**  is required to run a prepackaged version of the compiler.
 If you want to build it from source, you'll need a Java SDK + Kotlin 1.3.x SDK (or for instance,
 IntelliJ IDEA with the Kotlin plugin).
 
-It's handy to have a C-64 emulator or a real C-64 to run the programs on. The compiler assumes the presence
-of the [Vice emulator](http://vice-emu.sourceforge.net/)
+It's handy to have an emulator (or a real machine perhaps!) to run the programs on. The compiler assumes the presence
+of the [Vice emulator](http://vice-emu.sourceforge.net/)  for the C64 target,
+and a recent emulator version (R42 or newer) for the CommanderX16, such as [x16emu](https://cx16forum.com/forum/viewforum.php?f=30) 
+(preferred, this is the official emulator. If required, source code is [here](https://github.com/X16Community/x16-emulator/)).
+There is also [Box16](https://github.com/indigodarkwolf/box16) which has powerful debugging features.
+
+**Syntax highlighting:** for a few different editors, syntax highlighting definition files are provided.
+Look in the [syntax-files](https://github.com/irmen/prog8/tree/master/syntax-files) directory in the github repository to find them.
 
 
 Example code
@@ -66,44 +118,42 @@ Example code
 
 This code calculates prime numbers using the Sieve of Eratosthenes algorithm::
 
-    %import c64utils
+    %import textio
     %zeropage basicsafe
 
     main {
-
-        ubyte[256] sieve
-        ubyte candidate_prime = 2
-
+        bool[256] sieve
+        ubyte candidate_prime = 2       ; is increased in the loop
+    
         sub start() {
-            memset(sieve, 256, false)
-
-            c64scr.print("prime numbers up to 255:\n\n")
+            sys.memset(sieve, 256, 0)   ; clear the sieve
+            txt.print("prime numbers up to 255:\n\n")
             ubyte amount=0
-            while true {
+            repeat {
                 ubyte prime = find_next_prime()
                 if prime==0
                     break
-                c64scr.print_ub(prime)
-                c64scr.print(", ")
+                txt.print_ub(prime)
+                txt.print(", ")
                 amount++
             }
-            c64.CHROUT('\n')
-            c64scr.print("number of primes (expected 54): ")
-            c64scr.print_ub(amount)
-            c64.CHROUT('\n')
+            txt.nl()
+            txt.print("number of primes (expected 54): ")
+            txt.print_ub(amount)
+            txt.nl()
         }
-
-
+    
         sub find_next_prime() -> ubyte {
-
             while sieve[candidate_prime] {
                 candidate_prime++
                 if candidate_prime==0
-                    return 0
+                    return 0        ; we wrapped; no more primes
             }
-
+    
+            ; found next one, mark the multiples and return it.
             sieve[candidate_prime] = true
             uword multiple = candidate_prime
+    
             while multiple < len(sieve) {
                 sieve[lsb(multiple)] = true
                 multiple += candidate_prime
@@ -112,12 +162,10 @@ This code calculates prime numbers using the Sieve of Eratosthenes algorithm::
         }
     }
 
-
 when compiled an ran on a C-64 you'll get:
 
 ![c64 screen](docs/source/_static/primes_example.png)
 
-
 One of the included examples (wizzine.p8) animates a bunch of sprite balloons and looks like this:
 
 ![wizzine screen](docs/source/_static/wizzine.png)
@@ -129,3 +177,9 @@ Another example (cube3d-sprites.p8) draws the vertices of a rotating 3d cube:
 If you want to play a video game, a fully working Tetris clone is included in the examples:
 
 ![tehtriz_screen](docs/source/_static/tehtriz.png)
+
+There are a couple of examples specially made for the CommanderX16 compiler target.
+For instance here's a well known space ship animated in 3D with hidden line removal,
+in the CommanderX16 emulator:
+
+![cobra3d](docs/source/_static/cobra3d.png)

build.gradle

@@ -0,0 +1,10 @@
+plugins {
+    id "org.jetbrains.kotlin.jvm" version "$kotlinVersion" apply false
+}
+
+allprojects {
+    repositories {
+        mavenLocal()
+        mavenCentral()
+    }
+}

codeCore/build.gradle

@@ -0,0 +1,42 @@
+
+plugins {
+    id 'java'
+    id 'application'
+    id "org.jetbrains.kotlin.jvm"
+}
+
+java {
+    targetCompatibility = JavaLanguageVersion.of(javaVersion)
+    sourceCompatibility = JavaLanguageVersion.of(javaVersion)
+}
+
+compileKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+compileTestKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+dependencies {
+    // should have no dependencies to other modules
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
+    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:2.0.0"
+}
+
+sourceSets {
+    main {
+        java {
+            srcDir "${project.projectDir}/src"
+        }
+        resources {
+            srcDir "${project.projectDir}/res"
+        }
+    }
+}
+
+// note: there are no unit tests in this module!

codeCore/codeCore.iml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+      <excludeFolder url="file://$MODULE_DIR$/build" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="KotlinJavaRuntime" level="project" />
+    <orderEntry type="library" name="michael.bull.kotlin.result.jvm" level="project" />
+  </component>
+</module>

codeCore/src/prog8/code/Either.kt

@@ -0,0 +1,24 @@
+package prog8.code
+
+/**
+ * By convention, the right side of an `Either` is used to hold successful values.
+ */
+sealed class Either<out L, out R> {
+
+    data class Left<out L>(val value: L) : Either<L, Nothing>()
+
+    data class Right<out R>(val value: R) : Either<Nothing, R>()
+
+    fun isRight() = this is Right<R>
+
+    fun isLeft() = this is Left<L>
+
+    inline fun <C> fold(ifLeft: (L) -> C, ifRight: (R) -> C): C = when (this) {
+        is Right -> ifRight(value)
+        is Left -> ifLeft(value)
+    }
+
+}
+
+fun <L> left(a: L) = Either.Left(a)
+fun <R> right(b: R) = Either.Right(b)

codeCore/src/prog8/code/SymbolTable.kt

@@ -0,0 +1,256 @@
+package prog8.code
+
+import prog8.code.ast.PtNode
+import prog8.code.ast.PtProgram
+import prog8.code.core.*
+
+
+/**
+ * Tree structure containing all symbol definitions in the program
+ * (blocks, subroutines, variables (all types), memoryslabs, and labels).
+ */
+class SymbolTable(astProgram: PtProgram) : StNode(astProgram.name, StNodeType.GLOBAL, astProgram) {
+    /**
+     * The table as a flat mapping of scoped names to the StNode.
+     * This gives the fastest lookup possible (no need to traverse tree nodes)
+     */
+
+    private var cachedFlat: Map<String, StNode>? = null
+
+    val flat: Map<String, StNode> get()  {
+        if(cachedFlat!=null)
+            return cachedFlat!!
+
+        val result = mutableMapOf<String, StNode>()
+        fun collect(node: StNode) {
+            for(child in node.children) {
+                result[child.value.scopedName] = child.value
+                collect(child.value)
+            }
+        }
+        collect(this)
+        cachedFlat = result
+        return result
+    }
+
+    fun resetCachedFlat() {
+        cachedFlat = null
+    }
+
+    val allVariables: Collection<StStaticVariable> by lazy {
+        val vars = mutableListOf<StStaticVariable>()
+        fun collect(node: StNode) {
+            for(child in node.children) {
+                if(child.value.type== StNodeType.STATICVAR)
+                    vars.add(child.value as StStaticVariable)
+                else
+                    collect(child.value)
+            }
+        }
+        collect(this)
+        vars
+    }
+
+    val allMemMappedVariables: Collection<StMemVar> by lazy {
+        val vars = mutableListOf<StMemVar>()
+        fun collect(node: StNode) {
+            for(child in node.children) {
+                if(child.value.type== StNodeType.MEMVAR)
+                    vars.add(child.value as StMemVar)
+                else
+                    collect(child.value)
+            }
+        }
+        collect(this)
+        vars
+    }
+
+    val allMemorySlabs: Collection<StMemorySlab> by lazy {
+        val vars = mutableListOf<StMemorySlab>()
+        fun collect(node: StNode) {
+            for(child in node.children) {
+                if(child.value.type== StNodeType.MEMORYSLAB)
+                    vars.add(child.value as StMemorySlab)
+                else
+                    collect(child.value)
+            }
+        }
+        collect(this)
+        vars
+    }
+
+    override fun lookup(scopedName: String) = flat[scopedName]
+
+    fun getLength(name: String): Int? {
+        return when(val node = flat[name]) {
+            is StMemVar -> node.length
+            is StMemorySlab -> node.size.toInt()
+            is StStaticVariable -> node.length
+            else -> null
+        }
+    }
+}
+
+
+enum class StNodeType {
+    GLOBAL,
+    // MODULE,     // not used with current scoping rules
+    BLOCK,
+    SUBROUTINE,
+    ROMSUB,
+    LABEL,
+    STATICVAR,
+    MEMVAR,
+    CONSTANT,
+    BUILTINFUNC,
+    MEMORYSLAB
+}
+
+
+open class StNode(val name: String,
+                  val type: StNodeType,
+                  val astNode: PtNode,
+                  val children: MutableMap<String, StNode> = mutableMapOf()
+) {
+
+    lateinit var parent: StNode
+
+    val scopedName: String by lazy { scopedNameList.joinToString(".") }
+
+    open fun lookup(scopedName: String) =
+        lookup(scopedName.split('.'))
+
+    fun lookupUnscopedOrElse(name: String, default: () -> StNode) =
+        lookupUnscoped(name) ?: default()
+
+    fun lookupOrElse(scopedName: String, default: () -> StNode): StNode =
+        lookup(scopedName.split('.')) ?: default()
+
+    fun lookupUnscoped(name: String): StNode? {
+        // first consider the builtin functions
+        var globalscope = this
+        while(globalscope.type!= StNodeType.GLOBAL)
+            globalscope = globalscope.parent
+        val globalNode = globalscope.children[name]
+        if(globalNode!=null && globalNode.type== StNodeType.BUILTINFUNC)
+            return globalNode
+
+        // search for the unqualified name in the current scope or its parent scopes
+        var scope=this
+        while(true) {
+            val node = scope.children[name]
+            if(node!=null)
+                return node
+            if(scope.type== StNodeType.GLOBAL)
+                return null
+            else
+                scope = scope.parent
+        }
+    }
+
+    fun add(child: StNode) {
+        children[child.name] = child
+        child.parent = this
+    }
+
+    private val scopedNameList: List<String> by lazy {
+        if(type==StNodeType.GLOBAL)
+            emptyList()
+        else
+            parent.scopedNameList + name
+    }
+
+    private fun lookup(scopedName: List<String>): StNode? {
+        // a scoped name refers to a name in another namespace, and always stars from the root.
+        var node = this
+        while(node.type!=StNodeType.GLOBAL)
+            node = node.parent
+
+        for(name in scopedName) {
+            if(name in node.children)
+                node = node.children.getValue(name)
+            else
+                return null
+        }
+        return node
+    }
+}
+
+class StStaticVariable(name: String,
+                       val dt: DataType,
+                       val onetimeInitializationNumericValue: Double?,      // regular (every-run-time) initialization is done via regular assignments
+                       val onetimeInitializationStringValue: StString?,
+                       val onetimeInitializationArrayValue: StArray?,
+                       val length: Int?,            // for arrays: the number of elements, for strings: number of characters *including* the terminating 0-byte
+                       val zpwish: ZeropageWish,    // used in the variable allocator
+                       astNode: PtNode) : StNode(name, StNodeType.STATICVAR, astNode) {
+
+    val uninitialized = onetimeInitializationArrayValue==null && onetimeInitializationStringValue==null && onetimeInitializationNumericValue==null
+
+    init {
+        if(length!=null) {
+            require(onetimeInitializationNumericValue == null)
+            if(onetimeInitializationArrayValue!=null)
+                require(onetimeInitializationArrayValue.isEmpty() ||onetimeInitializationArrayValue.size==length)
+        }
+        if(onetimeInitializationNumericValue!=null) {
+            require(dt in NumericDatatypes || dt==DataType.BOOL)
+        }
+        if(onetimeInitializationArrayValue!=null) {
+            require(dt in ArrayDatatypes)
+            require(length==onetimeInitializationArrayValue.size)
+        }
+        if(onetimeInitializationStringValue!=null) {
+            require(dt == DataType.STR)
+            require(length == onetimeInitializationStringValue.first.length+1)
+        }
+    }
+}
+
+
+class StConstant(name: String, val dt: DataType, val value: Double, astNode: PtNode) :
+    StNode(name, StNodeType.CONSTANT, astNode)
+
+
+class StMemVar(name: String,
+               val dt: DataType,
+               val address: UInt,
+               val length: Int?,             // for arrays: the number of elements, for strings: number of characters *including* the terminating 0-byte
+               astNode: PtNode) :
+    StNode(name, StNodeType.MEMVAR, astNode) {
+
+    init{
+        require(dt!=DataType.BOOL && dt!=DataType.ARRAY_BOOL)
+        if(dt in ArrayDatatypes || dt == DataType.STR)
+            requireNotNull(length)
+    }
+}
+
+class StMemorySlab(
+    name: String,
+    val size: UInt,
+    val align: UInt,
+    astNode: PtNode
+):
+    StNode(name, StNodeType.MEMORYSLAB, astNode)
+
+
+class StSub(name: String, val parameters: List<StSubroutineParameter>, val returnType: DataType?, astNode: PtNode) :
+        StNode(name, StNodeType.SUBROUTINE, astNode)
+
+
+class StRomSub(name: String,
+               val address: UInt?,      // null in case of asmsub, specified in case of romsub
+               val parameters: List<StRomSubParameter>,
+               val returns: List<StRomSubParameter>,
+               astNode: PtNode) :
+    StNode(name, StNodeType.ROMSUB, astNode)
+
+
+
+class StSubroutineParameter(val name: String, val type: DataType)
+class StRomSubParameter(val register: RegisterOrStatusflag, val type: DataType)
+class StArrayElement(val number: Double?, val addressOfSymbol: String?, val boolean: Boolean?)
+
+typealias StString = Pair<String, Encoding>
+typealias StArray = List<StArrayElement>

codeCore/src/prog8/code/SymbolTableMaker.kt

@@ -0,0 +1,207 @@
+package prog8.code
+
+import prog8.code.ast.*
+import prog8.code.core.*
+import prog8.code.target.VMTarget
+import java.util.*
+
+class SymbolTableMaker(private val program: PtProgram, private val options: CompilationOptions) {
+    fun make(): SymbolTable {
+        val st = SymbolTable(program)
+
+        BuiltinFunctions.forEach {
+            st.add(StNode(it.key, StNodeType.BUILTINFUNC, PtIdentifier(it.key, it.value.returnType ?: DataType.UNDEFINED, Position.DUMMY)))
+        }
+
+        val scopestack = Stack<StNode>()
+        scopestack.push(st)
+        program.children.forEach {
+            addToSt(it, scopestack)
+        }
+        require(scopestack.size==1)
+
+        if(options.compTarget.name != VMTarget.NAME) {
+            listOf(
+                PtMemMapped("P8ZP_SCRATCH_B1", DataType.UBYTE, options.compTarget.machine.zeropage.SCRATCH_B1, null, Position.DUMMY),
+                PtMemMapped("P8ZP_SCRATCH_REG", DataType.UBYTE, options.compTarget.machine.zeropage.SCRATCH_REG, null, Position.DUMMY),
+                PtMemMapped("P8ZP_SCRATCH_W1", DataType.UWORD, options.compTarget.machine.zeropage.SCRATCH_W1, null, Position.DUMMY),
+                PtMemMapped("P8ZP_SCRATCH_W2", DataType.UWORD, options.compTarget.machine.zeropage.SCRATCH_W2, null, Position.DUMMY),
+            ).forEach {
+                it.parent = program
+                st.add(StMemVar(it.name, it.type, it.address, it.arraySize?.toInt(), it))
+            }
+        }
+
+        return st
+    }
+
+    private fun addToSt(node: PtNode, scope: Stack<StNode>) {
+        val stNode = when(node) {
+            is PtAsmSub -> {
+                val parameters = node.parameters.map { StRomSubParameter(it.first, it.second.type) }
+                val returns = node.returns.map { StRomSubParameter(it.first, it.second) }
+                StRomSub(node.name, node.address, parameters, returns, node)
+            }
+            is PtBlock -> {
+                StNode(node.name, StNodeType.BLOCK, node)
+            }
+            is PtConstant -> {
+                StConstant(node.name, node.type, node.value, node)
+            }
+            is PtLabel -> {
+                StNode(node.name, StNodeType.LABEL, node)
+            }
+            is PtMemMapped -> {
+                StMemVar(node.name, node.type, node.address, node.arraySize?.toInt(), node)
+            }
+            is PtSub -> {
+                val params = node.parameters.map {StSubroutineParameter(it.name, it.type) }
+                StSub(node.name, params, node.returntype, node)
+            }
+            is PtVariable -> {
+                val initialNumeric: Double?
+                val initialString: StString?
+                val initialArray: StArray?
+                val numElements: Int?
+                val value = node.value
+                if(value!=null) {
+                    val number = (value as? PtNumber)?.number
+                    initialNumeric = if(number==0.0) null else number       // 0 as init value -> just uninitialized
+                    when (value) {
+                        is PtString -> {
+                            initialString = StString(value.value, value.encoding)
+                            initialArray = null
+                            numElements = value.value.length + 1   // include the terminating 0-byte
+                        }
+                        is PtArray -> {
+                            initialArray = makeInitialArray(value)
+                            initialString = null
+                            numElements = initialArray.size
+                            require(node.arraySize?.toInt()==numElements)
+                        }
+                        else -> {
+                            initialString = null
+                            initialArray = null
+                            numElements = node.arraySize?.toInt()
+                        }
+                    }
+                } else {
+                    initialNumeric = null
+                    initialArray = null
+                    initialString = null
+                    numElements = node.arraySize?.toInt()
+                }
+//                if(node.type in SplitWordArrayTypes) {
+//                    ... split array also add _lsb and _msb to symboltable?
+//                }
+                StStaticVariable(node.name, node.type, initialNumeric, initialString, initialArray, numElements, node.zeropage, node)
+            }
+            is PtBuiltinFunctionCall -> {
+                if(node.name=="memory") {
+                    // memory slab allocations are a builtin functioncall in the program, but end up named as well in the symboltable
+                    require(node.name.all { it.isLetterOrDigit() || it=='_' }) {"memory name should be a valid symbol name"}
+                    val slabname = (node.args[0] as PtString).value
+                    val size = (node.args[1] as PtNumber).number.toUInt()
+                    val align = (node.args[2] as PtNumber).number.toUInt()
+                    // don't add memory slabs in nested scope, just put them in the top level of the ST
+                    scope.firstElement().add(StMemorySlab("prog8_memoryslab_$slabname", size, align, node))
+                }
+                null
+            }
+            else -> null // node is not present in the ST
+        }
+
+        if(stNode!=null) {
+            scope.peek().add(stNode)
+            scope.push(stNode)
+        }
+        node.children.forEach {
+            addToSt(it, scope)
+        }
+        if(stNode!=null)
+            scope.pop()
+    }
+
+    private fun makeInitialArray(value: PtArray): List<StArrayElement> {
+        return value.children.map {
+            when(it) {
+                is PtAddressOf -> {
+                    if(it.isFromArrayElement)
+                        TODO("address-of array element $it in initial array value")
+                    StArrayElement(null, it.identifier.name, null)
+                }
+                is PtIdentifier -> StArrayElement(null, it.name, null)
+                is PtNumber -> StArrayElement(it.number, null, null)
+                is PtBool -> StArrayElement(null, null, it.value)
+                else -> throw AssemblyError("invalid array element $it")
+            }
+        }
+    }
+
+}
+
+//    override fun visit(decl: VarDecl) {
+//        val node =
+//            when(decl.type) {
+//                VarDeclType.VAR -> {
+//                    var initialNumeric = (decl.value as? NumericLiteral)?.number
+//                    if(initialNumeric==0.0)
+//                        initialNumeric=null     // variable will go into BSS and this will be set to 0
+//                    val initialStringLit = decl.value as? StringLiteral
+//                    val initialString = if(initialStringLit==null) null else Pair(initialStringLit.value, initialStringLit.encoding)
+//                    val initialArrayLit = decl.value as? ArrayLiteral
+//                    val initialArray = makeInitialArray(initialArrayLit)
+//                    if(decl.isArray && decl.datatype !in ArrayDatatypes)
+//                        throw FatalAstException("array vardecl has mismatched dt ${decl.datatype}")
+//                    val numElements =
+//                        if(decl.isArray)
+//                            decl.arraysize!!.constIndex()
+//                        else if(initialStringLit!=null)
+//                            initialStringLit.value.length+1  // include the terminating 0-byte
+//                        else
+//                            null
+//                    val bss = if(decl.datatype==DataType.STR)
+//                        false
+//                    else if(decl.isArray)
+//                        initialArray.isNullOrEmpty()
+//                    else
+//                        initialNumeric == null
+//                    val astNode = PtVariable(decl.name, decl.datatype, null, null, decl.position)
+//                    StStaticVariable(decl.name, decl.datatype, bss, initialNumeric, initialString, initialArray, numElements, decl.zeropage, astNode, decl.position)
+//                }
+//                VarDeclType.CONST -> {
+//                    val astNode = PtVariable(decl.name, decl.datatype, null, null, decl.position)
+//                    StConstant(decl.name, decl.datatype, (decl.value as NumericLiteral).number, astNode, decl.position)
+//                }
+//                VarDeclType.MEMORY -> {
+//                    val numElements =
+//                        if(decl.isArray)
+//                            decl.arraysize!!.constIndex()
+//                        else null
+//                    val astNode = PtVariable(decl.name, decl.datatype, null, null, decl.position)
+//                    StMemVar(decl.name, decl.datatype, (decl.value as NumericLiteral).number.toUInt(), numElements, astNode, decl.position)
+//                }
+//            }
+//        scopestack.peek().add(node)
+//        // st.origAstLinks[decl] = node
+//    }
+//
+//    private fun makeInitialArray(arrayLit: ArrayLiteral?): StArray? {
+//        if(arrayLit==null)
+//            return null
+//        return arrayLit.value.map {
+//            when(it){
+//                is AddressOf -> {
+//                    val scopedName = it.identifier.targetNameAndType(program).first
+//                    StArrayElement(null, scopedName)
+//                }
+//                is IdentifierReference -> {
+//                    val scopedName = it.targetNameAndType(program).first
+//                    StArrayElement(null, scopedName)
+//                }
+//                is NumericLiteral -> StArrayElement(it.number, null)
+//                else -> throw FatalAstException("weird element dt in array literal")
+//            }
+//        }.toList()
+//    }
+//

codeCore/src/prog8/code/ast/AstBase.kt

@@ -0,0 +1,128 @@
+package prog8.code.ast
+
+import prog8.code.core.IMemSizer
+import prog8.code.core.IStringEncoding
+import prog8.code.core.Position
+import prog8.code.core.SourceCode
+import java.nio.file.Path
+
+// New simplified AST for the code generator.
+
+
+sealed class PtNode(val position: Position) {
+
+    val children = mutableListOf<PtNode>()
+    lateinit var parent: PtNode
+
+    fun add(child: PtNode) {
+        children.add(child)
+        child.parent = this
+    }
+
+    fun add(index: Int, child: PtNode) {
+        children.add(index, child)
+        child.parent = this
+    }
+
+    fun definingBlock() = findParentNode<PtBlock>(this)
+    fun definingSub() = findParentNode<PtSub>(this)
+    fun definingAsmSub() = findParentNode<PtAsmSub>(this)
+    fun definingISub() = findParentNode<IPtSubroutine>(this)
+}
+
+
+sealed interface IPtStatementContainer
+
+
+class PtNodeGroup : PtNode(Position.DUMMY), IPtStatementContainer
+
+
+sealed class PtNamedNode(var name: String, position: Position): PtNode(position) {
+    // Note that as an exception, the 'name' is not read-only
+    // but a var. This is to allow for cheap node renames.
+    val scopedName: String
+        get() {
+            var namedParent: PtNode = this.parent
+            return if(namedParent is PtProgram)
+                name
+            else {
+                while (namedParent !is PtNamedNode)
+                    namedParent = namedParent.parent
+                namedParent.scopedName + "." + name
+            }
+        }
+}
+
+
+class PtProgram(
+    val name: String,
+    val memsizer: IMemSizer,
+    val encoding: IStringEncoding
+) : PtNode(Position.DUMMY) {
+
+//    fun allModuleDirectives(): Sequence<PtDirective> =
+//        children.asSequence().flatMap { it.children }.filterIsInstance<PtDirective>().distinct()
+
+    fun allBlocks(): Sequence<PtBlock> =
+        children.asSequence().filterIsInstance<PtBlock>()
+
+    fun entrypoint(): PtSub? =
+        // returns the main.start subroutine if it exists
+        allBlocks().firstOrNull { it.name == "main" || it.name=="p8b_main" }
+            ?.children
+            ?.firstOrNull { it is PtSub && (it.name == "start" || it.name=="main.start" || it.name=="p8s_start" || it.name=="p8b_main.p8s_start") } as PtSub?
+}
+
+
+class PtBlock(name: String,
+              val library: Boolean,
+              val source: SourceCode,       // taken from the module the block is defined in.
+              val options: Options,
+              position: Position
+) : PtNamedNode(name, position), IPtStatementContainer {
+    enum class BlockAlignment {
+        NONE,
+        WORD,
+        PAGE
+    }
+
+    class Options(val address: UInt? = null,
+                  val forceOutput: Boolean = false,
+                  val noSymbolPrefixing: Boolean = false,
+                  val veraFxMuls: Boolean = false,
+                  val ignoreUnused: Boolean = false,
+                  val alignment: BlockAlignment = BlockAlignment.NONE)
+}
+
+
+class PtInlineAssembly(val assembly: String, val isIR: Boolean, position: Position) : PtNode(position) {
+    init {
+        require(!assembly.startsWith('\n') && !assembly.startsWith('\r')) { "inline assembly should be trimmed" }
+        require(!assembly.endsWith('\n') && !assembly.endsWith('\r')) { "inline assembly should be trimmed" }
+    }
+}
+
+
+class PtLabel(name: String, position: Position) : PtNamedNode(name, position)
+
+
+class PtBreakpoint(position: Position): PtNode(position)
+
+
+class PtIncludeBinary(val file: Path, val offset: UInt?, val length: UInt?, position: Position) : PtNode(position)
+
+
+class PtNop(position: Position): PtNode(position)
+
+
+// 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: PtNode): T? {
+    var candidate = node.parent
+    while(candidate !is T && candidate !is PtProgram)
+        candidate = candidate.parent
+    return if(candidate is PtProgram)
+        null
+    else
+        candidate as T
+}

codeCore/src/prog8/code/ast/AstExpressions.kt

@@ -0,0 +1,352 @@
+package prog8.code.ast
+
+import prog8.code.core.*
+import java.util.*
+import kotlin.math.abs
+import kotlin.math.truncate
+
+
+sealed class PtExpression(val type: DataType, position: Position) : PtNode(position) {
+
+    init {
+        if(type==DataType.UNDEFINED) {
+            @Suppress("LeakingThis")
+            when(this) {
+                is PtBuiltinFunctionCall -> { /* void function call */ }
+                is PtFunctionCall -> { /* void function call */ }
+                is PtIdentifier -> { /* non-variable identifier */ }
+                else -> throw IllegalArgumentException("type should be known @$position")
+            }
+        }
+    }
+
+    infix fun isSameAs(other: PtExpression): Boolean {
+        return when(this) {
+            is PtAddressOf -> {
+                if(other !is PtAddressOf)
+                    return false
+                if (other.type!==type || !(other.identifier isSameAs identifier))
+                    return false
+                if(other.children.size!=children.size)
+                    return false
+                if(children.size==1)
+                    return true
+                return arrayIndexExpr!! isSameAs other.arrayIndexExpr!!
+            }
+            is PtArrayIndexer -> other is PtArrayIndexer && other.type==type && other.variable isSameAs variable && other.index isSameAs index && other.splitWords==splitWords
+            is PtBinaryExpression -> {
+                if(other !is PtBinaryExpression || other.operator!=operator)
+                    false
+                else if(operator in AssociativeOperators)
+                    (other.left isSameAs left && other.right isSameAs right) || (other.left isSameAs right && other.right isSameAs left)
+                else
+                    other.left isSameAs left && other.right isSameAs right
+            }
+            is PtContainmentCheck -> other is PtContainmentCheck && other.type==type && other.element isSameAs element && other.iterable isSameAs iterable
+            is PtIdentifier -> other is PtIdentifier && other.type==type && other.name==name
+            is PtIrRegister -> other is PtIrRegister && other.type==type && other.register==register
+            is PtMemoryByte -> other is PtMemoryByte && other.address isSameAs address
+            is PtNumber -> other is PtNumber && other.type==type && other.number==number
+            is PtBool -> other is PtBool && other.value==value
+            is PtPrefix -> other is PtPrefix && other.type==type && other.operator==operator && other.value isSameAs value
+            is PtRange -> other is PtRange && other.type==type && other.from==from && other.to==to && other.step==step
+            is PtTypeCast -> other is PtTypeCast && other.type==type && other.value isSameAs value
+            else -> false
+        }
+    }
+
+    infix fun isSameAs(target: PtAssignTarget): Boolean {
+        return when {
+            target.memory != null && this is PtMemoryByte-> {
+                target.memory!!.address isSameAs this.address
+            }
+            target.identifier != null && this is PtIdentifier -> {
+                this.name == target.identifier!!.name
+            }
+            target.array != null && this is PtArrayIndexer -> {
+                this.variable.name == target.array!!.variable.name && this.index isSameAs target.array!!.index && this.splitWords==target.array!!.splitWords
+            }
+            else -> false
+        }
+    }
+
+    fun asConstInteger(): Int? = (this as? PtNumber)?.number?.toInt() ?: (this as? PtBool)?.asInt()
+
+    fun isSimple(): Boolean {
+        return when(this) {
+            is PtAddressOf -> true
+            is PtArray -> true
+            is PtArrayIndexer -> index is PtNumber || index is PtIdentifier
+            is PtBinaryExpression -> false
+            is PtBuiltinFunctionCall -> {
+                when (name) {
+                    in arrayOf("msb", "lsb", "mkword", "set_carry", "set_irqd", "clear_carry", "clear_irqd") -> this.args.all { it.isSimple() }
+                    else -> false
+                }
+            }
+            is PtContainmentCheck -> false
+            is PtFunctionCall -> false
+            is PtIdentifier -> true
+            is PtIrRegister -> true
+            is PtMemoryByte -> address is PtNumber || address is PtIdentifier
+            is PtBool -> true
+            is PtNumber -> true
+            is PtPrefix -> value.isSimple()
+            is PtRange -> true
+            is PtString -> true
+            is PtTypeCast -> value.isSimple()
+        }
+    }
+
+    /*
+    fun clone(): PtExpression {
+        fun withClonedChildrenFrom(orig: PtExpression, clone: PtExpression): PtExpression {
+            orig.children.forEach { clone.add((it as PtExpression).clone()) }
+            return clone
+        }
+        when(this) {
+            is PtAddressOf -> return withClonedChildrenFrom(this, PtAddressOf(position))
+            is PtArray -> return withClonedChildrenFrom(this, PtArray(type, position))
+            is PtArrayIndexer -> return withClonedChildrenFrom(this, PtArrayIndexer(type, position))
+            is PtBinaryExpression -> return withClonedChildrenFrom(this, PtBinaryExpression(operator, type, position))
+            is PtBuiltinFunctionCall -> return withClonedChildrenFrom(this, PtBuiltinFunctionCall(name, void, hasNoSideEffects, type, position))
+            is PtContainmentCheck -> return withClonedChildrenFrom(this, PtContainmentCheck(position))
+            is PtFunctionCall -> return withClonedChildrenFrom(this, PtFunctionCall(name, void, type, position))
+            is PtIdentifier -> return withClonedChildrenFrom(this, PtIdentifier(name, type, position))
+            is PtMachineRegister -> return withClonedChildrenFrom(this, PtMachineRegister(register, type, position))
+            is PtMemoryByte -> return withClonedChildrenFrom(this, PtMemoryByte(position))
+            is PtNumber -> return withClonedChildrenFrom(this, PtNumber(type, number, position))
+            is PtBool -> return withClonedChildrenFrom(this, PtBool(value, position))
+            is PtPrefix -> return withClonedChildrenFrom(this, PtPrefix(operator, type, position))
+            is PtRange -> return withClonedChildrenFrom(this, PtRange(type, position))
+            is PtString -> return withClonedChildrenFrom(this, PtString(value, encoding, position))
+            is PtTypeCast -> return withClonedChildrenFrom(this, PtTypeCast(type, position))
+        }
+    }
+    */
+}
+
+class PtAddressOf(position: Position) : PtExpression(DataType.UWORD, position) {
+    val identifier: PtIdentifier
+        get() = children[0] as PtIdentifier
+    val arrayIndexExpr: PtExpression?
+        get() = if(children.size==2) children[1] as PtExpression else null
+
+    val isFromArrayElement: Boolean
+        get() = children.size==2
+}
+
+
+class PtArrayIndexer(elementType: DataType, position: Position): PtExpression(elementType, position) {
+    val variable: PtIdentifier
+        get() = children[0] as PtIdentifier
+    val index: PtExpression
+        get() = children[1] as PtExpression
+    val splitWords: Boolean
+        get() = variable.type in SplitWordArrayTypes
+
+    init {
+        require(elementType in NumericDatatypesWithBoolean)
+    }
+}
+
+
+class PtArray(type: DataType, position: Position): PtExpression(type, position) {
+    override fun hashCode(): Int = Objects.hash(children, type)
+    override fun equals(other: Any?): Boolean {
+        if(other==null || other !is PtArray)
+            return false
+        return type==other.type && children == other.children
+    }
+
+    val size: Int
+        get() = children.size
+}
+
+
+class PtBuiltinFunctionCall(val name: String,
+                            val void: Boolean,
+                            val hasNoSideEffects: Boolean,
+                            type: DataType,
+                            position: Position) : PtExpression(type, position) {
+    init {
+        if(!void)
+            require(type!=DataType.UNDEFINED)
+    }
+
+    val args: List<PtExpression>
+        get() = children.map { it as PtExpression }
+}
+
+
+class PtBinaryExpression(val operator: String, type: DataType, position: Position): PtExpression(type, position) {
+    val left: PtExpression
+        get() = children[0] as PtExpression
+    val right: PtExpression
+        get() = children[1] as PtExpression
+
+    init {
+        if(operator in ComparisonOperators + LogicalOperators)
+            require(type==DataType.BOOL)
+        else
+            require(type!=DataType.BOOL) { "no bool allowed for this operator $operator"}
+    }
+}
+
+
+class PtContainmentCheck(position: Position): PtExpression(DataType.BOOL, position) {
+    val element: PtExpression
+        get() = children[0] as PtExpression
+    val iterable: PtIdentifier
+        get() = children[1] as PtIdentifier
+}
+
+
+class PtFunctionCall(val name: String,
+                     val void: Boolean,
+                     type: DataType,
+                     position: Position) : PtExpression(type, position) {
+    val args: List<PtExpression>
+        get() = children.map { it as PtExpression }
+}
+
+
+class PtIdentifier(val name: String, type: DataType, position: Position) : PtExpression(type, position) {
+    override fun toString(): String {
+        return "[PtIdentifier:$name $type $position]"
+    }
+
+    fun copy() = PtIdentifier(name, type, position)
+}
+
+
+class PtMemoryByte(position: Position) : PtExpression(DataType.UBYTE, position) {
+    val address: PtExpression
+        get() = children.single() as PtExpression
+}
+
+
+class PtBool(val value: Boolean, position: Position) : PtExpression(DataType.BOOL, position) {
+
+    companion object {
+        fun fromNumber(number: Number, position: Position): PtBool =
+            PtBool(number != 0.0, position)
+    }
+
+    override fun hashCode(): Int = Objects.hash(type, value)
+
+    override fun equals(other: Any?): Boolean {
+        if(other==null || other !is PtBool)
+            return false
+        return value==other.value
+    }
+
+    override fun toString() = "PtBool:$value"
+
+    fun asInt(): Int = if(value) 1 else 0
+}
+
+
+class PtNumber(type: DataType, val number: Double, position: Position) : PtExpression(type, position) {
+
+    companion object {
+        fun fromBoolean(bool: Boolean, position: Position): PtNumber =
+            PtNumber(DataType.UBYTE, if(bool) 1.0 else 0.0, position)
+    }
+
+    init {
+        if(type==DataType.BOOL)
+            throw IllegalArgumentException("use PtBool instead")
+        if(type!=DataType.FLOAT) {
+            val trunc = truncate(number)
+            if (trunc != number)
+                throw IllegalArgumentException("refused truncating of float to avoid loss of precision @$position")
+        }
+    }
+
+    override fun hashCode(): Int = Objects.hash(type, number)
+
+    override fun equals(other: Any?): Boolean {
+        return if(other==null || other !is PtNumber)
+            false
+        else if(type!=DataType.BOOL && other.type!=DataType.BOOL)
+            number==other.number
+        else
+            type==other.type && number==other.number
+    }
+
+    operator fun compareTo(other: PtNumber): Int = number.compareTo(other.number)
+
+    override fun toString() = "PtNumber:$type:$number"
+}
+
+
+class PtPrefix(val operator: String, type: DataType, position: Position): PtExpression(type, position) {
+    val value: PtExpression
+        get() = children.single() as PtExpression
+
+    init {
+        require(operator in setOf("+", "-", "~", "not")) { "invalid prefix operator: $operator" }
+    }
+}
+
+
+class PtRange(type: DataType, position: Position) : PtExpression(type, position) {
+    val from: PtExpression
+        get() = children[0] as PtExpression
+    val to: PtExpression
+        get() = children[1] as PtExpression
+    val step: PtNumber
+        get() = children[2] as PtNumber
+
+    fun toConstantIntegerRange(): IntProgression? {
+        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)
+                }
+            }
+        }
+
+        val fromLv = from as? PtNumber
+        val toLv = to as? PtNumber
+        val stepLv = step as? PtNumber
+        if(fromLv==null || toLv==null || stepLv==null)
+            return null
+        val fromVal = fromLv.number.toInt()
+        val toVal = toLv.number.toInt()
+        val stepVal = stepLv.number.toInt()
+        return makeRange(fromVal, toVal, stepVal)
+    }
+}
+
+
+class PtString(val value: String, val encoding: Encoding, position: Position) : PtExpression(DataType.STR, position) {
+    override fun hashCode(): Int = Objects.hash(value, encoding)
+    override fun equals(other: Any?): Boolean {
+        if(other==null || other !is PtString)
+            return false
+        return value==other.value && encoding == other.encoding
+    }
+}
+
+
+class PtTypeCast(type: DataType, position: Position) : PtExpression(type, position) {
+    val value: PtExpression
+        get() = children.single() as PtExpression
+}
+
+
+// special node that isn't created from compiling user code, but used internally in the Intermediate Code
+class PtIrRegister(val register: Int, type: DataType, position: Position) : PtExpression(type, position)
+
+
+fun constValue(expr: PtExpression): Double? = if(expr is PtNumber) expr.number else if(expr is PtBool) expr.asInt().toDouble() else null
+fun constIntValue(expr: PtExpression): Int? = if(expr is PtNumber) expr.number.toInt() else if(expr is PtBool) expr.asInt() else null

codeCore/src/prog8/code/ast/AstPrinter.kt

@@ -0,0 +1,181 @@
+package prog8.code.ast
+
+import prog8.code.core.*
+
+/**
+ * Produces readable text from a [PtNode] (AST node, usually starting with PtProgram as root),
+ * passing it as a String to the specified receiver function.
+ */
+fun printAst(root: PtNode, skipLibraries: Boolean, output: (text: String) -> Unit) {
+    fun type(dt: DataType) = "!${dt.name.lowercase()}!"
+    fun txt(node: PtNode): String {
+        return when(node) {
+            is PtAssignTarget -> if(node.void) "<void>" else "<target>"
+            is PtAssignment -> "<assign>"
+            is PtAugmentedAssign -> "<inplace-assign> ${node.operator}"
+            is PtBreakpoint -> "%breakpoint"
+            is PtConditionalBranch -> "if_${node.condition.name.lowercase()}"
+            is PtAddressOf -> {
+                if(node.isFromArrayElement)
+                    "& array-element"
+                else
+                    "&"
+            }
+            is PtArray -> "array len=${node.children.size} ${type(node.type)}"
+            is PtArrayIndexer -> "<arrayindexer> ${type(node.type)} ${if(node.splitWords) "[splitwords]" else ""}"
+            is PtBinaryExpression -> "<expr> ${node.operator} ${type(node.type)}"
+            is PtBuiltinFunctionCall -> {
+                val str = if(node.void) "void " else ""
+                str + node.name + "()"
+            }
+            is PtContainmentCheck -> "in"
+            is PtFunctionCall -> {
+                val str = if(node.void) "void " else ""
+                str + node.name + "()"
+            }
+            is PtIdentifier -> "${node.name} ${type(node.type)}"
+            is PtIrRegister -> "IRREG#${node.register} ${type(node.type)}"
+            is PtMemoryByte -> "@()"
+            is PtNumber -> {
+                val numstr = if(node.type == DataType.FLOAT) node.number.toString() else node.number.toHex()
+                "$numstr ${type(node.type)}"
+            }
+            is PtBool -> node.value.toString()
+            is PtPrefix -> node.operator
+            is PtRange -> "<range>"
+            is PtString -> "\"${node.value.escape()}\""
+            is PtTypeCast -> "as ${node.type.name.lowercase()}"
+            is PtForLoop -> "for"
+            is PtIfElse -> "ifelse"
+            is PtIncludeBinary -> "%incbin '${node.file}', ${node.offset}, ${node.length}"
+            is PtInlineAssembly -> {
+                if(node.isIR)
+                    "%ir {{ ...${node.assembly.length} characters... }}"
+                else
+                    "%asm {{ ...${node.assembly.length} characters... }}"
+            }
+            is PtJump -> {
+                if(node.identifier!=null)
+                    "goto ${node.identifier.name}"
+                else if(node.address!=null)
+                    "goto ${node.address.toHex()}"
+                else
+                    "???"
+            }
+            is PtAsmSub -> {
+                val params = node.parameters.joinToString(", ") {
+                    val register = it.first.registerOrPair
+                    val statusflag = it.first.statusflag
+                    "${it.second.type} ${it.second.name} @${register ?: statusflag}"
+                }
+                val clobbers = if (node.clobbers.isEmpty()) "" else "clobbers ${node.clobbers}"
+                val returns = if (node.returns.isEmpty()) "" else {
+                    "-> ${node.returns.joinToString(", ") {
+                            val register = it.first.registerOrPair
+                            val statusflag = it.first.statusflag
+                            "${it.second} @${register ?: statusflag}"
+                        }
+                    }"
+                }
+                val str = if (node.inline) "inline " else ""
+                if(node.address==null) {
+                    str + "asmsub ${node.name}($params) $clobbers $returns"
+                } else {
+                    str + "romsub ${node.address.toHex()} = ${node.name}($params) $clobbers $returns"
+                }
+            }
+            is PtBlock -> {
+                val addr = if(node.options.address==null) "" else "@${node.options.address.toHex()}"
+                val align = if(node.options.alignment==PtBlock.BlockAlignment.NONE) "" else "align=${node.options.alignment}"
+                "\nblock '${node.name}' $addr $align"
+            }
+            is PtConstant -> {
+                val value = when(node.type) {
+                    DataType.BOOL -> if(node.value==0.0) "false" else "true"
+                    in IntegerDatatypes -> node.value.toInt().toString()
+                    else -> node.value.toString()
+                }
+                "const ${node.type.name.lowercase()} ${node.name} = $value"
+            }
+            is PtLabel -> "${node.name}:"
+            is PtMemMapped -> {
+                if(node.type in ArrayDatatypes) {
+                    val arraysize = if(node.arraySize==null) "" else node.arraySize.toString()
+                    val eltType = ArrayToElementTypes.getValue(node.type)
+                    "&${eltType.name.lowercase()}[$arraysize] ${node.name} = ${node.address.toHex()}"
+                } else {
+                    "&${node.type.name.lowercase()} ${node.name} = ${node.address.toHex()}"
+                }
+            }
+            is PtSub -> {
+                val params = node.parameters.joinToString(", ") { "${it.type} ${it.name}" }
+                var str = "sub ${node.name}($params) "
+                if(node.returntype!=null)
+                    str += "-> ${node.returntype.name.lowercase()}"
+                str
+            }
+            is PtVariable -> {
+                val split = if(node.type in SplitWordArrayTypes) "@split" else ""
+                val str = if(node.arraySize!=null) {
+                    val eltType = ArrayToElementTypes.getValue(node.type)
+                    "${eltType.name.lowercase()}[${node.arraySize}] $split ${node.name}"
+                }
+                else if(node.type in ArrayDatatypes) {
+                    val eltType = ArrayToElementTypes.getValue(node.type)
+                    "${eltType.name.lowercase()}[] $split ${node.name}"
+                }
+                else
+                    "${node.type.name.lowercase()} ${node.name}"
+                if(node.value!=null)
+                    str + " = " + txt(node.value)
+                else
+                    str
+            }
+            is PtNodeGroup -> if(node.children.isNotEmpty()) "<group>" else ""
+            is PtNop -> "nop"
+            is PtProgram -> "PROGRAM ${node.name}"
+            is PtRepeatLoop -> "repeat"
+            is PtReturn -> "return"
+            is PtSubroutineParameter -> "${node.type.name.lowercase()} ${node.name}"
+            is PtWhen -> "when"
+            is PtWhenChoice -> {
+                if(node.isElse)
+                    "else"
+                else
+                    "->"
+            }
+        }
+    }
+
+    if(root is PtProgram) {
+        output(txt(root))
+        root.children.forEach {
+            walkAst(it) { node, depth ->
+                val txt = txt(node)
+                val library = if(node is PtBlock) node.library else node.definingBlock()?.library==true
+                if(!library || !skipLibraries) {
+                    if (txt.isNotEmpty())
+                        output("    ".repeat(depth) + txt(node))
+                }
+            }
+        }
+        println()
+    } else {
+        walkAst(root) { node, depth ->
+            val txt = txt(node)
+            val library = if(node is PtBlock) node.library else node.definingBlock()?.library==true
+            if(!library || !skipLibraries) {
+                if (txt.isNotEmpty())
+                    output("    ".repeat(depth) + txt(node))
+            }
+        }
+    }
+}
+
+fun walkAst(root: PtNode, act: (node: PtNode, depth: Int) -> Unit) {
+    fun recurse(node: PtNode, depth: Int) {
+        act(node, depth)
+        node.children.forEach { recurse(it, depth+1) }
+    }
+    recurse(root, 0)
+}

codeCore/src/prog8/code/ast/AstStatements.kt

@@ -0,0 +1,180 @@
+package prog8.code.ast
+
+import prog8.code.core.*
+
+
+sealed interface IPtSubroutine {
+    val name: String
+}
+
+class PtAsmSub(
+    name: String,
+    val address: UInt?,
+    val clobbers: Set<CpuRegister>,
+    val parameters: List<Pair<RegisterOrStatusflag, PtSubroutineParameter>>,
+    val returns: List<Pair<RegisterOrStatusflag, DataType>>,
+    val inline: Boolean,
+    position: Position
+) : PtNamedNode(name, position), IPtSubroutine
+
+
+class PtSub(
+    name: String,
+    val parameters: List<PtSubroutineParameter>,
+    val returntype: DataType?,
+    position: Position
+) : PtNamedNode(name, position), IPtSubroutine, IPtStatementContainer {
+    init {
+        // params and return value should not be str
+        if(parameters.any{ it.type !in NumericDatatypes && it.type!=DataType.BOOL })
+            throw AssemblyError("non-numeric/non-bool parameter")
+        if(returntype!=null && returntype !in NumericDatatypes && returntype!=DataType.BOOL)
+            throw AssemblyError("non-numeric/non-bool returntype $returntype")
+        parameters.forEach { it.parent=this }
+    }
+}
+
+
+class PtSubroutineParameter(name: String, val type: DataType, position: Position): PtNamedNode(name, position)
+
+
+sealed interface IPtAssignment {
+    val children: MutableList<PtNode>
+    val target: PtAssignTarget
+        get() {
+            if(children.size==2)
+                return children[0] as PtAssignTarget
+            else if(children.size<2)
+                throw AssemblyError("incomplete node")
+            else
+                throw AssemblyError("no singular target")
+        }
+    val value: PtExpression
+        get() = children.last() as PtExpression
+    val multiTarget: Boolean
+        get() = children.size>2
+}
+
+class PtAssignment(position: Position) : PtNode(position), IPtAssignment
+
+class PtAugmentedAssign(val operator: String, position: Position) : PtNode(position), IPtAssignment
+
+
+class PtAssignTarget(val void: Boolean, position: Position) : PtNode(position) {
+    val identifier: PtIdentifier?
+        get() = children.single() as? PtIdentifier
+    val array: PtArrayIndexer?
+        get() = children.single() as? PtArrayIndexer
+    val memory: PtMemoryByte?
+        get() = children.single() as? PtMemoryByte
+
+    val type: DataType
+        get() {
+            return when(val tgt = children.single()) {
+                is PtIdentifier -> tgt.type
+                is PtArrayIndexer -> tgt.type
+                is PtMemoryByte -> tgt.type
+                else -> throw AssemblyError("weird target $tgt")
+            }
+        }
+
+    infix fun isSameAs(expression: PtExpression): Boolean = !void && expression.isSameAs(this)
+}
+
+
+class PtConditionalBranch(val condition: BranchCondition, position: Position) : PtNode(position) {
+    val trueScope: PtNodeGroup
+        get() = children[0] as PtNodeGroup
+    val falseScope: PtNodeGroup
+        get() = children[1] as PtNodeGroup
+}
+
+
+class PtForLoop(position: Position) : PtNode(position) {
+    val variable: PtIdentifier
+        get() = children[0] as PtIdentifier
+    val iterable: PtExpression
+        get() = children[1] as PtExpression
+    val statements: PtNodeGroup
+        get() = children[2] as PtNodeGroup
+}
+
+
+class PtIfElse(position: Position) : PtNode(position) {
+    val condition: PtExpression
+        get() = children[0] as PtExpression
+    val ifScope: PtNodeGroup
+        get() = children[1] as PtNodeGroup
+    val elseScope: PtNodeGroup
+        get() = children[2] as PtNodeGroup
+
+    fun hasElse(): Boolean = children.size==3 && elseScope.children.isNotEmpty()
+}
+
+
+class PtJump(val identifier: PtIdentifier?,     // note: even ad-hoc labels are wrapped as an Identifier to simplify code. Just use dummy type and position.
+             val address: UInt?,
+             position: Position) : PtNode(position) {
+    init {
+        identifier?.let {it.parent = this }
+    }
+}
+
+
+class PtRepeatLoop(position: Position) : PtNode(position) {
+    val count: PtExpression
+        get() = children[0] as PtExpression
+    val statements: PtNodeGroup
+        get() = children[1] as PtNodeGroup
+}
+
+
+class PtReturn(position: Position) : PtNode(position) {
+    val hasValue = children.any()
+    val value: PtExpression?
+        get() {
+            return if(children.any())
+                children.single() as PtExpression
+            else
+                null
+        }
+}
+
+
+sealed interface IPtVariable {
+    val name: String
+    val type: DataType
+}
+
+
+class PtVariable(name: String, override val type: DataType, val zeropage: ZeropageWish, val value: PtExpression?, val arraySize: UInt?, position: Position) : PtNamedNode(name, position), IPtVariable {
+    init {
+        value?.let {it.parent=this}
+    }
+}
+
+
+class PtConstant(name: String, override val type: DataType, val value: Double, position: Position) : PtNamedNode(name, position), IPtVariable
+
+
+class PtMemMapped(name: String, override val type: DataType, val address: UInt, val arraySize: UInt?, position: Position) : PtNamedNode(name, position), IPtVariable {
+    init {
+        require(type!=DataType.BOOL && type!=DataType.ARRAY_BOOL)
+    }
+}
+
+
+class PtWhen(position: Position) : PtNode(position) {
+    val value: PtExpression
+        get() = children[0] as PtExpression
+    val choices: PtNodeGroup
+        get() = children[1] as PtNodeGroup
+}
+
+
+class PtWhenChoice(val isElse: Boolean, position: Position) : PtNode(position) {
+    val values: PtNodeGroup
+        get() = children[0] as PtNodeGroup
+    val statements: PtNodeGroup
+        get() = children[1] as PtNodeGroup
+}

codeCore/src/prog8/code/core/BuiltinFunctions.kt

@@ -0,0 +1,138 @@
+package prog8.code.core
+
+class ReturnConvention(val dt: DataType?, val reg: RegisterOrPair?, val floatFac1: Boolean)
+class ParamConvention(val dt: DataType, val reg: RegisterOrPair?, val variable: Boolean)
+class CallConvention(val params: List<ParamConvention>, val returns: ReturnConvention) {
+    override fun toString(): String {
+        val paramConvs =  params.mapIndexed { index, it ->
+            when {
+                it.reg!=null -> "$index:${it.reg}"
+                it.variable -> "$index:variable"
+                else -> "$index:???"
+            }
+        }
+        val returnConv =
+            when {
+                returns.reg!=null -> returns.reg.toString()
+                returns.floatFac1 -> "floatFAC1"
+                else -> "<no returnvalue>"
+            }
+        return "CallConvention[" + paramConvs.joinToString() + " ; returns: $returnConv]"
+    }
+}
+
+class FParam(val name: String, val possibleDatatypes: Array<DataType>)
+
+class FSignature(val pure: Boolean,      // does it have side effects?
+                      val parameters: List<FParam>,
+                      val returnType: DataType?) {
+
+    fun callConvention(actualParamTypes: List<DataType>): CallConvention {
+        val returns: ReturnConvention = when (returnType) {
+            DataType.UBYTE, DataType.BYTE -> ReturnConvention(returnType, RegisterOrPair.A, false)
+            DataType.UWORD, DataType.WORD -> ReturnConvention(returnType, RegisterOrPair.AY, false)
+            DataType.FLOAT -> ReturnConvention(returnType, null, true)
+            in PassByReferenceDatatypes -> ReturnConvention(returnType!!, RegisterOrPair.AY, false)
+            null -> ReturnConvention(null, null, false)
+            else -> {
+                // return type depends on arg type
+                when (val paramType = actualParamTypes.first()) {
+                    DataType.UBYTE, DataType.BYTE -> ReturnConvention(paramType, RegisterOrPair.A, false)
+                    DataType.UWORD, DataType.WORD -> ReturnConvention(paramType, RegisterOrPair.AY, false)
+                    DataType.FLOAT -> ReturnConvention(paramType, null, true)
+                    in PassByReferenceDatatypes -> ReturnConvention(paramType, RegisterOrPair.AY, false)
+                    else -> ReturnConvention(paramType, null, false)
+                }
+            }
+        }
+
+        return when {
+            actualParamTypes.isEmpty() -> CallConvention(emptyList(), returns)
+            actualParamTypes.size==1 -> {
+                // one parameter goes via register/registerpair
+                val paramConv = when(val paramType = actualParamTypes[0]) {
+                    DataType.UBYTE, DataType.BYTE -> ParamConvention(paramType, RegisterOrPair.A, false)
+                    DataType.UWORD, DataType.WORD -> ParamConvention(paramType, RegisterOrPair.AY, false)
+                    DataType.FLOAT -> ParamConvention(paramType, RegisterOrPair.AY, false)
+                    in PassByReferenceDatatypes -> ParamConvention(paramType, RegisterOrPair.AY, false)
+                    else -> ParamConvention(paramType, null, false)
+                }
+                CallConvention(listOf(paramConv), returns)
+            }
+            else -> {
+                // multiple parameters go via variables
+                val paramConvs = actualParamTypes.map { ParamConvention(it, null, true) }
+                CallConvention(paramConvs, returns)
+            }
+        }
+    }
+}
+
+val BuiltinFunctions: Map<String, FSignature> = mapOf(
+    // this set of function have no return value and operate in-place:
+    "setlsb"    to FSignature(false, listOf(FParam("variable", arrayOf(DataType.WORD, DataType.UWORD)), FParam("value", arrayOf(DataType.BYTE, DataType.UBYTE))), null),
+    "setmsb"    to FSignature(false, listOf(FParam("variable", arrayOf(DataType.WORD, DataType.UWORD)), FParam("value", arrayOf(DataType.BYTE, DataType.UBYTE))), null),
+    "rol"       to FSignature(false, listOf(FParam("item", arrayOf(DataType.UBYTE, DataType.UWORD))), null),
+    "ror"       to FSignature(false, listOf(FParam("item", arrayOf(DataType.UBYTE, DataType.UWORD))), null),
+    "rol2"      to FSignature(false, listOf(FParam("item", arrayOf(DataType.UBYTE, DataType.UWORD))), null),
+    "ror2"      to FSignature(false, listOf(FParam("item", arrayOf(DataType.UBYTE, DataType.UWORD))), null),
+    // cmp returns a status in the carry flag, but not a proper return value
+    "cmp"       to FSignature(false, listOf(FParam("value1", IntegerDatatypes), FParam("value2", NumericDatatypes)), null),
+    "prog8_lib_stringcompare"     to FSignature(true, listOf(FParam("str1", arrayOf(DataType.STR)), FParam("str2", arrayOf(DataType.STR))), DataType.BYTE),
+    "prog8_lib_arraycopy"         to FSignature(false, listOf(FParam("source", ArrayDatatypes), FParam("target", ArrayDatatypes)), null),
+    "prog8_lib_square_byte"       to FSignature(true, listOf(FParam("value", arrayOf(DataType.BYTE, DataType.UBYTE))), DataType.UBYTE),
+    "prog8_lib_square_word"       to FSignature(true, listOf(FParam("value", arrayOf(DataType.WORD, DataType.UWORD))), DataType.UWORD),
+    "prog8_ifelse_bittest_set"    to FSignature(true, listOf(FParam("variable", ByteDatatypes), FParam("bitnumber", arrayOf(DataType.UBYTE))), DataType.BOOL),
+    "prog8_ifelse_bittest_notset" to FSignature(true, listOf(FParam("variable", ByteDatatypes), FParam("bitnumber", arrayOf(DataType.UBYTE))), DataType.BOOL),
+    "abs"       to FSignature(true, listOf(FParam("value", NumericDatatypes)), null),
+    "abs__byte"  to FSignature(true, listOf(FParam("value", arrayOf(DataType.BYTE))), DataType.BYTE),
+    "abs__word"  to FSignature(true, listOf(FParam("value", arrayOf(DataType.WORD))), DataType.WORD),
+    "abs__float" to FSignature(true, listOf(FParam("value", arrayOf(DataType.FLOAT))), DataType.FLOAT),
+    "len"       to FSignature(true, listOf(FParam("values", IterableDatatypes)), DataType.UWORD),
+    // normal functions follow:
+    "sizeof"    to FSignature(true, listOf(FParam("object", DataType.entries.toTypedArray())), DataType.UBYTE),
+    "sgn"       to FSignature(true, listOf(FParam("value", NumericDatatypes)), DataType.BYTE),
+    "sqrt"        to FSignature(true, listOf(FParam("value", NumericDatatypes)), null),
+    "sqrt__ubyte" to FSignature(true, listOf(FParam("value", arrayOf(DataType.UBYTE))), DataType.UBYTE),
+    "sqrt__uword" to FSignature(true, listOf(FParam("value", arrayOf(DataType.UWORD))), DataType.UBYTE),
+    "sqrt__float" to FSignature(true, listOf(FParam("value", arrayOf(DataType.FLOAT))), DataType.FLOAT),
+    "divmod"           to FSignature(false, listOf(FParam("dividend", arrayOf(DataType.UBYTE, DataType.UWORD)), FParam("divisor", arrayOf(DataType.UBYTE, DataType.UWORD)), FParam("quotient", arrayOf(DataType.UBYTE, DataType.UWORD)), FParam("remainder", arrayOf(DataType.UBYTE, DataType.UWORD))), null),
+    "divmod__ubyte"    to FSignature(false, listOf(FParam("dividend", arrayOf(DataType.UBYTE)), FParam("divisor", arrayOf(DataType.UBYTE)), FParam("quotient", arrayOf(DataType.UBYTE)), FParam("remainder", arrayOf(DataType.UBYTE))), null),
+    "divmod__uword"    to FSignature(false, listOf(FParam("dividend", arrayOf(DataType.UWORD)), FParam("divisor", arrayOf(DataType.UWORD)), FParam("quotient", arrayOf(DataType.UWORD)), FParam("remainder", arrayOf(DataType.UWORD))), null),
+    "lsb"       to FSignature(true, listOf(FParam("value", arrayOf(DataType.UWORD, DataType.WORD))), DataType.UBYTE),
+    "msb"       to FSignature(true, listOf(FParam("value", arrayOf(DataType.UWORD, DataType.WORD))), DataType.UBYTE),
+    "mkword"    to FSignature(true, listOf(FParam("msb", arrayOf(DataType.UBYTE)), FParam("lsb", arrayOf(DataType.UBYTE))), DataType.UWORD),
+    "clamp"     to FSignature(true, listOf(FParam("value", arrayOf(DataType.BYTE)), FParam("minimum", arrayOf(DataType.BYTE)), FParam("maximum", arrayOf(DataType.BYTE))), null),
+    "clamp__byte"  to FSignature(true, listOf(FParam("value", arrayOf(DataType.BYTE)), FParam("minimum", arrayOf(DataType.BYTE)), FParam("maximum", arrayOf(DataType.BYTE))), DataType.BYTE),
+    "clamp__ubyte" to FSignature(true, listOf(FParam("value", arrayOf(DataType.UBYTE)), FParam("minimum", arrayOf(DataType.UBYTE)), FParam("maximum", arrayOf(DataType.UBYTE))), DataType.UBYTE),
+    "clamp__word"  to FSignature(true, listOf(FParam("value", arrayOf(DataType.WORD)), FParam("minimum", arrayOf(DataType.WORD)), FParam("maximum", arrayOf(DataType.WORD))), DataType.WORD),
+    "clamp__uword" to FSignature(true, listOf(FParam("value", arrayOf(DataType.UWORD)), FParam("minimum", arrayOf(DataType.UWORD)), FParam("maximum", arrayOf(DataType.UWORD))), DataType.UWORD),
+    "min"        to FSignature(true, listOf(FParam("val1", arrayOf(DataType.BYTE)), FParam("val2", arrayOf(DataType.BYTE))), null),
+    "min__byte"  to FSignature(true, listOf(FParam("val1", arrayOf(DataType.BYTE)), FParam("val2", arrayOf(DataType.BYTE))), DataType.BYTE),
+    "min__ubyte" to FSignature(true, listOf(FParam("val1", arrayOf(DataType.UBYTE)), FParam("val2", arrayOf(DataType.UBYTE))), DataType.UBYTE),
+    "min__word"  to FSignature(true, listOf(FParam("val1", arrayOf(DataType.WORD)), FParam("val2", arrayOf(DataType.WORD))), DataType.WORD),
+    "min__uword" to FSignature(true, listOf(FParam("val1", arrayOf(DataType.UWORD)), FParam("val2", arrayOf(DataType.UWORD))), DataType.UWORD),
+    "max"        to FSignature(true, listOf(FParam("val1", arrayOf(DataType.BYTE)), FParam("val2", arrayOf(DataType.BYTE))), null),
+    "max__byte"  to FSignature(true, listOf(FParam("val1", arrayOf(DataType.BYTE)), FParam("val2", arrayOf(DataType.BYTE))), DataType.BYTE),
+    "max__ubyte" to FSignature(true, listOf(FParam("val1", arrayOf(DataType.UBYTE)), FParam("val2", arrayOf(DataType.UBYTE))), DataType.UBYTE),
+    "max__word"  to FSignature(true, listOf(FParam("val1", arrayOf(DataType.WORD)), FParam("val2", arrayOf(DataType.WORD))), DataType.WORD),
+    "max__uword" to FSignature(true, listOf(FParam("val1", arrayOf(DataType.UWORD)), FParam("val2", arrayOf(DataType.UWORD))), DataType.UWORD),
+    "peek"      to FSignature(true, listOf(FParam("address", arrayOf(DataType.UWORD))), DataType.UBYTE),
+    "peekw"     to FSignature(true, listOf(FParam("address", arrayOf(DataType.UWORD))), DataType.UWORD),
+    "peekf"     to FSignature(true, listOf(FParam("address", arrayOf(DataType.UWORD))), DataType.FLOAT),
+    "poke"      to FSignature(false, listOf(FParam("address", arrayOf(DataType.UWORD)), FParam("value", arrayOf(DataType.UBYTE))), null),
+    "pokew"     to FSignature(false, listOf(FParam("address", arrayOf(DataType.UWORD)), FParam("value", arrayOf(DataType.UWORD))), null),
+    "pokef"     to FSignature(false, listOf(FParam("address", arrayOf(DataType.UWORD)), FParam("value", arrayOf(DataType.FLOAT))), null),
+    "pokemon"   to FSignature(false, listOf(FParam("address", arrayOf(DataType.UWORD)), FParam("value", arrayOf(DataType.UBYTE))), DataType.UBYTE),
+    "rsave"     to FSignature(false, emptyList(), null),
+    "rrestore"  to FSignature(false, emptyList(), null),
+    "memory"    to FSignature(true, listOf(FParam("name", arrayOf(DataType.STR)), FParam("size", arrayOf(DataType.UWORD)), FParam("alignment", arrayOf(DataType.UWORD))), DataType.UWORD),
+    "callfar"   to FSignature(false, listOf(FParam("bank", arrayOf(DataType.UBYTE)), FParam("address", arrayOf(DataType.UWORD)), FParam("arg", arrayOf(DataType.UWORD))), DataType.UWORD),
+    "call"      to FSignature(false, listOf(FParam("address", arrayOf(DataType.UWORD))), DataType.UWORD),
+)
+
+val InplaceModifyingBuiltinFunctions = setOf(
+    "setlsb", "setmsb",
+    "rol", "ror", "rol2", "ror2",
+    "divmod", "divmod__ubyte", "divmod__uword"
+)

codeCore/src/prog8/code/core/CompilationOptions.kt

@@ -0,0 +1,42 @@
+package prog8.code.core
+
+import java.nio.file.Path
+import kotlin.io.path.Path
+
+
+class CompilationOptions(val output: OutputType,
+                         val launcher: CbmPrgLauncherType,
+                         val zeropage: ZeropageType,
+                         val zpReserved: List<UIntRange>,
+                         val zpAllowed: List<UIntRange>,
+                         val floats: Boolean,
+                         val noSysInit: Boolean,
+                         val compTarget: ICompilationTarget,
+                         // these are set later, based on command line arguments or options in the source code:
+                         var loadAddress: UInt,
+                         var warnSymbolShadowing: Boolean = false,
+                         var optimize: Boolean = false,
+                         var asmQuiet: Boolean = false,
+                         var asmListfile: Boolean = false,
+                         var includeSourcelines: Boolean = false,
+                         var dumpVariables: Boolean = false,
+                         var dumpSymbols: Boolean = false,
+                         var experimentalCodegen: Boolean = false,
+                         var varsHighBank: Int? = null,
+                         var varsGolden: Boolean = false,
+                         var slabsHighBank: Int? = null,
+                         var slabsGolden: Boolean = false,
+                         var splitWordArrays: Boolean = false,
+                         var strictBool: Boolean = true,
+                         var breakpointCpuInstruction: String? = null,
+                         var outputDir: Path = Path(""),
+                         var symbolDefs: Map<String, String> = emptyMap()
+) {
+    init {
+        compTarget.machine.initializeMemoryAreas(this)
+    }
+
+    companion object {
+        val AllZeropageAllowed: List<UIntRange> = listOf(0u..255u)
+    }
+}

codeCore/src/prog8/code/core/Conversions.kt

@@ -0,0 +1,95 @@
+package prog8.code.core
+
+import kotlin.math.abs
+import kotlin.math.pow
+
+val powersOfTwoFloat = (0..16).map { (2.0).pow(it) }.toTypedArray()
+val negativePowersOfTwoFloat = powersOfTwoFloat.map { -it }.toTypedArray()
+val powersOfTwoInt = (0..16).map { 2.0.pow(it).toInt() }.toTypedArray()
+
+fun Number.toHex(): String {
+    //  0..15 -> "0".."15"
+    //  16..255 -> "$10".."$ff"
+    //  256..65536 -> "$0100".."$ffff"
+    // negative values are prefixed with '-'.
+    val integer = this.toInt()
+    if(integer<0)
+        return '-' + abs(integer).toHex()
+    return when (integer) {
+        in 0 until 16 -> integer.toString()
+        in 0 until 0x100 -> "$"+integer.toString(16).padStart(2,'0')
+        in 0 until 0x10000 -> "$"+integer.toString(16).padStart(4,'0')
+        else -> throw IllegalArgumentException("number too large for 16 bits $this")
+    }
+}
+
+fun UInt.toHex(): String {
+    //  0..15 -> "0".."15"
+    //  16..255 -> "$10".."$ff"
+    //  256..65536 -> "$0100".."$ffff"
+    return when (this) {
+        in 0u until 16u -> this.toString()
+        in 0u until 0x100u -> "$"+this.toString(16).padStart(2,'0')
+        in 0u until 0x10000u -> "$"+this.toString(16).padStart(4,'0')
+        else -> throw IllegalArgumentException("number too large for 16 bits $this")
+    }
+}
+
+fun Char.escape(): Char = this.toString().escape()[0]
+
+fun String.escape(): String {
+    val es = this.map {
+        when(it) {
+            '\t' -> "\\t"
+            '\n' -> "\\n"
+            '\r' -> "\\r"
+            '"' -> "\\\""
+            in '\u8000'..'\u80ff' -> "\\x" + (it.code - 0x8000).toString(16).padStart(2, '0')       // 'ugly' passthrough hack
+            in '\u0000'..'\u00ff' -> it.toString()
+            else -> "\\u" + it.code.toString(16).padStart(4, '0')
+        }
+    }
+    return es.joinToString("")
+}
+
+fun String.unescape(): String {
+    val result = mutableListOf<Char>()
+    val iter = this.iterator()
+    while(iter.hasNext()) {
+        val c = iter.nextChar()
+        if(c=='\\') {
+            val ec = iter.nextChar()
+            result.add(when(ec) {
+                '\\' -> '\\'
+                'n' -> '\n'
+                'r' -> '\r'
+                't' -> '\t'
+                '"' -> '"'
+                '\'' -> '\''
+                'u' -> {
+                    try {
+                        "${iter.nextChar()}${iter.nextChar()}${iter.nextChar()}${iter.nextChar()}".toInt(16).toChar()
+                    } catch (sb: StringIndexOutOfBoundsException) {
+                        throw IllegalArgumentException("invalid \\u escape sequence")
+                    } catch (nf: NumberFormatException) {
+                        throw IllegalArgumentException("invalid \\u escape sequence")
+                    }
+                }
+                'x' -> {
+                    try {
+                        val hex = ("" + iter.nextChar() + iter.nextChar()).toInt(16)
+                        (0x8000 + hex).toChar()         // 'ugly' pass-through hack
+                    } catch (sb: StringIndexOutOfBoundsException) {
+                        throw IllegalArgumentException("invalid \\x escape sequence")
+                    } catch (nf: NumberFormatException) {
+                        throw IllegalArgumentException("invalid \\x escape sequence")
+                    }
+                }
+                else -> throw IllegalArgumentException("invalid escape char in string: \\$ec")
+            })
+        } else {
+            result.add(c)
+        }
+    }
+    return result.joinToString("")
+}

codeCore/src/prog8/code/core/Enumerations.kt

@@ -0,0 +1,205 @@
+package prog8.code.core
+
+enum class DataType {
+    UBYTE,              // pass by value            8 bits unsigned
+    BYTE,               // pass by value            8 bits signed
+    UWORD,              // pass by value            16 bits unsigned
+    WORD,               // pass by value            16 bits signed
+    LONG,               // pass by value            32 bits signed
+    FLOAT,              // pass by value            machine dependent
+    BOOL,               // pass by value            bit 0 of a 8 bit byte
+    STR,                // pass by reference
+    ARRAY_UB,           // pass by reference
+    ARRAY_B,            // pass by reference
+    ARRAY_UW,           // pass by reference
+    ARRAY_UW_SPLIT,     // pass by reference, lo/hi byte split
+    ARRAY_W,            // pass by reference
+    ARRAY_W_SPLIT,      // pass by reference, lo/hi byte split
+    ARRAY_F,            // pass by reference
+    ARRAY_BOOL,         // pass by reference
+    UNDEFINED;
+
+    /**
+     * is the type assignable to the given other type (perhaps via a typecast) without loss of precision?
+     */
+    infix fun isAssignableTo(targetType: DataType) =
+        when(this) {
+            BOOL -> targetType == BOOL
+            UBYTE -> targetType.oneOf(UBYTE, WORD, UWORD, LONG, FLOAT)
+            BYTE -> targetType.oneOf(BYTE, WORD, LONG, FLOAT)
+            UWORD -> targetType.oneOf(UWORD, LONG, FLOAT)
+            WORD -> targetType.oneOf(WORD, LONG, FLOAT)
+            LONG -> targetType.oneOf(LONG, FLOAT)
+            FLOAT -> targetType.oneOf(FLOAT)
+            STR -> targetType.oneOf(STR, UWORD)
+            in ArrayDatatypes -> targetType == this
+            else -> false
+        }
+
+    fun oneOf(vararg types: DataType) = this in types
+
+    infix fun largerThan(other: DataType) =
+        when {
+            this == other -> false
+            this in ByteDatatypesWithBoolean -> false
+            this in WordDatatypes -> other in ByteDatatypesWithBoolean
+            this == LONG -> other in ByteDatatypesWithBoolean+WordDatatypes
+            this == STR && other == UWORD || this == UWORD && other == STR -> false
+            else -> true
+        }
+
+    infix fun equalsSize(other: DataType) =
+        when {
+            this == other -> true
+            this in ByteDatatypesWithBoolean -> other in ByteDatatypesWithBoolean
+            this in WordDatatypes -> other in WordDatatypes
+            this== STR && other== UWORD || this== UWORD && other== STR -> true
+            else -> false
+        }
+}
+
+enum class CpuRegister {
+    A,
+    X,
+    Y
+}
+
+enum class RegisterOrPair {
+    A,
+    X,
+    Y,
+    AX,
+    AY,
+    XY,
+    FAC1,
+    FAC2,
+    // cx16 virtual registers:
+    R0, R1, R2, R3, R4, R5, R6, R7,
+    R8, R9, R10, R11, R12, R13, R14, R15;
+
+    companion object {
+        val names by lazy { entries.map { it.toString()} }
+        fun fromCpuRegister(cpu: CpuRegister): RegisterOrPair {
+            return when(cpu) {
+                CpuRegister.A -> A
+                CpuRegister.X -> X
+                CpuRegister.Y -> Y
+            }
+        }
+    }
+
+    fun asCpuRegister(): CpuRegister = when(this) {
+        A -> CpuRegister.A
+        X -> CpuRegister.X
+        Y -> CpuRegister.Y
+        else -> throw IllegalArgumentException("no cpu hardware register for $this")
+    }
+
+}       // only used in parameter and return value specs in asm subroutines
+
+enum class Statusflag {
+    Pc,
+    Pz,     // don't use
+    Pv,
+    Pn;     // don't use
+
+    companion object {
+        val names by lazy { entries.map { it.toString()} }
+    }
+}
+
+enum class BranchCondition {
+    CS,
+    CC,
+    EQ,     // EQ == Z
+    Z,
+    NE,     // NE == NZ
+    NZ,
+    MI,     // MI == NEG
+    NEG,
+    PL,     // PL == POS
+    POS,
+    VS,
+    VC
+}
+
+
+val ByteDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE)
+val ByteDatatypesWithBoolean = ByteDatatypes + DataType.BOOL
+val WordDatatypes = arrayOf(DataType.UWORD, DataType.WORD)
+val IntegerDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD, DataType.LONG)
+val IntegerDatatypesWithBoolean = IntegerDatatypes + DataType.BOOL
+val NumericDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD, DataType.LONG, DataType.FLOAT)
+val NumericDatatypesWithBoolean = NumericDatatypes + DataType.BOOL
+val SignedDatatypes =  arrayOf(DataType.BYTE, DataType.WORD, DataType.LONG, DataType.FLOAT)
+val ArrayDatatypes = arrayOf(DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_UW_SPLIT, DataType.ARRAY_W, DataType.ARRAY_W_SPLIT, DataType.ARRAY_F, DataType.ARRAY_BOOL)
+val StringlyDatatypes = arrayOf(DataType.STR, DataType.ARRAY_UB, DataType.ARRAY_B, DataType.UWORD)
+val SplitWordArrayTypes = arrayOf(DataType.ARRAY_UW_SPLIT, DataType.ARRAY_W_SPLIT)
+val IterableDatatypes = arrayOf(
+    DataType.STR,
+    DataType.ARRAY_UB, DataType.ARRAY_B,
+    DataType.ARRAY_UW, DataType.ARRAY_W,
+    DataType.ARRAY_UW_SPLIT, DataType.ARRAY_W_SPLIT,
+    DataType.ARRAY_F, DataType.ARRAY_BOOL
+)
+val PassByValueDatatypes = NumericDatatypesWithBoolean
+val PassByReferenceDatatypes = IterableDatatypes
+val ArrayToElementTypes = 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_W_SPLIT to DataType.WORD,
+    DataType.ARRAY_UW_SPLIT to DataType.UWORD,
+    DataType.ARRAY_F to DataType.FLOAT,
+    DataType.ARRAY_BOOL to DataType.BOOL
+)
+val ElementToArrayTypes = mapOf(
+    DataType.BYTE to DataType.ARRAY_B,
+    DataType.UBYTE to DataType.ARRAY_UB,
+    DataType.WORD to DataType.ARRAY_W,
+    DataType.UWORD to DataType.ARRAY_UW,
+    DataType.FLOAT to DataType.ARRAY_F,
+    DataType.BOOL to DataType.ARRAY_BOOL,
+    DataType.STR to DataType.ARRAY_UW          // array of str is just an array of pointers
+)
+
+val Cx16VirtualRegisters = arrayOf(
+    RegisterOrPair.R0, RegisterOrPair.R1, RegisterOrPair.R2, RegisterOrPair.R3,
+    RegisterOrPair.R4, RegisterOrPair.R5, RegisterOrPair.R6, RegisterOrPair.R7,
+    RegisterOrPair.R8, RegisterOrPair.R9, RegisterOrPair.R10, RegisterOrPair.R11,
+    RegisterOrPair.R12, RegisterOrPair.R13, RegisterOrPair.R14, RegisterOrPair.R15
+)
+
+val CpuRegisters = setOf(
+    RegisterOrPair.A, RegisterOrPair.X, RegisterOrPair.Y,
+    RegisterOrPair.AX, RegisterOrPair.AY, RegisterOrPair.XY
+)
+
+
+enum class OutputType {
+    RAW,
+    PRG,
+    XEX
+}
+
+enum class CbmPrgLauncherType {
+    BASIC,
+    NONE
+}
+
+enum class ZeropageType {
+    BASICSAFE,
+    FLOATSAFE,
+    KERNALSAFE,
+    FULL,
+    DONTUSE
+}
+
+enum class ZeropageWish {
+    REQUIRE_ZEROPAGE,
+    PREFER_ZEROPAGE,
+    DONTCARE,
+    NOT_IN_ZEROPAGE
+}

codeCore/src/prog8/code/core/Exceptions.kt

@@ -0,0 +1,7 @@
+package prog8.code.core
+
+class InternalCompilerException(message: String?) : Exception(message)
+
+class AssemblyError(msg: String) : RuntimeException(msg)
+
+class ErrorsReportedException(message: String?) : Exception(message)

codeCore/src/prog8/code/core/ICodeGeneratorBackend.kt

@@ -0,0 +1,17 @@
+package prog8.code.core
+
+import prog8.code.SymbolTable
+import prog8.code.ast.PtProgram
+
+interface ICodeGeneratorBackend {
+    fun generate(program: PtProgram,
+                 symbolTable: SymbolTable,
+                 options: CompilationOptions,
+                 errors: IErrorReporter): IAssemblyProgram?
+}
+
+
+interface IAssemblyProgram {
+    val name: String
+    fun assemble(options: CompilationOptions, errors: IErrorReporter): Boolean
+}

codeCore/src/prog8/code/core/ICompilationTarget.kt

@@ -0,0 +1,9 @@
+package prog8.code.core
+
+interface ICompilationTarget: IStringEncoding, IMemSizer {
+    val name: String
+    val machine: IMachineDefinition
+
+    override fun encodeString(str: String, encoding: Encoding): List<UByte>
+    override fun decodeString(bytes: Iterable<UByte>, encoding: Encoding): String
+}

codeCore/src/prog8/code/core/IErrorReporter.kt

@@ -0,0 +1,16 @@
+package prog8.code.core
+
+interface IErrorReporter {
+    fun err(msg: String, position: Position)
+    fun warn(msg: String, position: Position)
+    fun info(msg: String, position: Position)
+    fun undefined(symbol: List<String>, position: Position)
+    fun noErrors(): Boolean
+    fun report()
+    fun finalizeNumErrors(numErrors: Int, numWarnings: Int, numInfos: Int) {
+        if(numErrors>0)
+            throw ErrorsReportedException("There are $numErrors errors, $numWarnings warnings, and $numInfos infos.")
+    }
+
+    fun noErrorForLine(position: Position): Boolean
+}

codeCore/src/prog8/code/core/IMachineDefinition.kt

@@ -0,0 +1,34 @@
+package prog8.code.core
+
+import java.nio.file.Path
+
+
+enum class CpuType {
+    CPU6502,
+    CPU65c02,
+    VIRTUAL
+}
+
+interface IMachineDefinition {
+    val FLOAT_MAX_NEGATIVE: Double
+    val FLOAT_MAX_POSITIVE: Double
+    val FLOAT_MEM_SIZE: Int
+    val PROGRAM_LOAD_ADDRESS : UInt
+    val BSSHIGHRAM_START: UInt
+    val BSSHIGHRAM_END: UInt
+    val BSSGOLDENRAM_START: UInt
+    val BSSGOLDENRAM_END: UInt
+
+    val cpu: CpuType
+    var zeropage: Zeropage
+    var golden: GoldenRam
+
+    fun initializeMemoryAreas(compilerOptions: CompilationOptions)
+    fun getFloatAsmBytes(num: Number): String
+
+    fun convertFloatToBytes(num: Double): List<UByte>
+    fun convertBytesToFloat(bytes: List<UByte>): Double
+
+    fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path)
+    fun isIOAddress(address: UInt): Boolean
+}

codeCore/src/prog8/code/core/IMemSizer.kt

@@ -0,0 +1,6 @@
+package prog8.code.core
+
+interface IMemSizer {
+    fun memorySize(dt: DataType): Int
+    fun memorySize(arrayDt: DataType, numElements: Int): Int
+}

codeCore/src/prog8/code/core/IStringEncoding.kt

@@ -0,0 +1,20 @@
+package prog8.code.core
+
+enum class Encoding(val prefix: String) {
+    DEFAULT("default"),         // depends on compilation target
+    PETSCII("petscii"),         // c64/c128/cx16
+    SCREENCODES("sc"),          // c64/c128/cx16
+    ATASCII("atascii"),         // atari
+    ISO("iso"),                 // cx16  (iso-8859-15)
+    ISO5("iso5"),               // cx16  (iso-8859-5, cyrillic)
+    ISO16("iso16"),             // cx16  (iso-8859-16, eastern european)
+    CP437("cp437"),             // cx16  (ibm pc, codepage 437)
+    KATAKANA("kata")                 // cx16  (katakana)
+}
+
+interface IStringEncoding {
+    val defaultEncoding: Encoding
+
+    fun encodeString(str: String, encoding: Encoding): List<UByte>
+    fun decodeString(bytes: Iterable<UByte>, encoding: Encoding): String
+}

codeCore/src/prog8/code/core/MemoryRegions.kt

@@ -0,0 +1,173 @@
+package prog8.code.core
+
+import com.github.michaelbull.result.Err
+import com.github.michaelbull.result.Ok
+import com.github.michaelbull.result.Result
+
+
+class MemAllocationError(message: String) : Exception(message)
+
+
+abstract class MemoryAllocator(protected val options: CompilationOptions) {
+    data class VarAllocation(val address: UInt, val dt: DataType, val size: Int)
+
+    abstract fun allocate(name: String,
+                          datatype: DataType,
+                          numElements: Int?,
+                          position: Position?,
+                          errors: IErrorReporter): Result<VarAllocation, MemAllocationError>
+}
+
+
+abstract class Zeropage(options: CompilationOptions): MemoryAllocator(options) {
+
+    abstract val SCRATCH_B1 : UInt      // temp storage for a single byte
+    abstract val SCRATCH_REG : UInt     // temp storage for a register, must be B1+1
+    abstract val SCRATCH_W1 : UInt      // temp storage 1 for a word  $fb+$fc
+    abstract val SCRATCH_W2 : UInt      // temp storage 2 for a word  $fb+$fc
+
+
+    // the variables allocated into Zeropage.
+    // name (scoped) ==> pair of address to (Datatype + bytesize)
+    val allocatedVariables = mutableMapOf<String, VarAllocation>()
+
+    val free = mutableListOf<UInt>()     // subclasses must set this to the appropriate free locations.
+
+    fun removeReservedFromFreePool() {
+        synchronized(this) {
+            for (reserved in options.zpReserved)
+                reserve(reserved)
+
+            free.removeAll(setOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_W1, SCRATCH_W1 + 1u, SCRATCH_W2, SCRATCH_W2 + 1u))
+        }
+    }
+
+    fun retainAllowed() {
+        synchronized(this) {
+            for(allowed in options.zpAllowed)
+                free.retainAll { it in allowed }
+        }
+    }
+
+    fun availableBytes() = if(options.zeropage== ZeropageType.DONTUSE) 0 else free.size
+    fun hasByteAvailable() = if(options.zeropage== ZeropageType.DONTUSE) false else free.isNotEmpty()
+    fun hasWordAvailable(): Boolean {
+        if(options.zeropage== ZeropageType.DONTUSE)
+            return false
+
+        return free.windowed(2).any { it[0] == it[1] - 1u }
+    }
+
+    override fun allocate(name: String,
+                          datatype: DataType,
+                          numElements: Int?,
+                          position: Position?,
+                          errors: IErrorReporter): Result<VarAllocation, MemAllocationError> {
+
+        require(name.isEmpty() || name !in allocatedVariables) {"name can't be allocated twice"}
+
+        if(options.zeropage== ZeropageType.DONTUSE)
+            return Err(MemAllocationError("zero page usage has been disabled"))
+
+        val size: Int =
+                when (datatype) {
+                    in IntegerDatatypesWithBoolean -> options.compTarget.memorySize(datatype)
+                    DataType.STR, in ArrayDatatypes  -> {
+                        val memsize = options.compTarget.memorySize(datatype, numElements!!)
+                        if(position!=null)
+                            errors.warn("allocating a large value in zeropage; str/array $memsize bytes", position)
+                        else
+                            errors.warn("$name: allocating a large value in zeropage; str/array $memsize bytes", Position.DUMMY)
+                        memsize
+                    }
+                    DataType.FLOAT -> {
+                        if (options.floats) {
+                            val memsize = options.compTarget.memorySize(DataType.FLOAT)
+                            if(position!=null)
+                                errors.warn("allocating a large value in zeropage; float $memsize bytes", position)
+                            else
+                                errors.warn("$name: allocating a large value in zeropage; float $memsize bytes", Position.DUMMY)
+                            memsize
+                        } else return Err(MemAllocationError("floating point option not enabled"))
+                    }
+                    else -> throw MemAllocationError("weird dt")
+                }
+
+        synchronized(this) {
+            if(free.size > 0) {
+                if(size==1) {
+                    for(candidate in free.minOrNull()!! .. free.maxOrNull()!!+1u) {
+                        if(oneSeparateByteFree(candidate))
+                            return Ok(VarAllocation(makeAllocation(candidate, 1, datatype, name), datatype,1))
+                    }
+                    return Ok(VarAllocation(makeAllocation(free[0], 1, datatype, name), datatype,1))
+                }
+                for(candidate in free.minOrNull()!! .. free.maxOrNull()!!+1u) {
+                    if (sequentialFree(candidate, size))
+                        return Ok(VarAllocation(makeAllocation(candidate, size, datatype, name), datatype, size))
+                }
+            }
+        }
+
+        return Err(MemAllocationError("no more free space in ZP to allocate $size sequential bytes"))
+    }
+
+    private fun reserve(range: UIntRange) = free.removeAll(range)
+
+    private fun makeAllocation(address: UInt, size: Int, datatype: DataType, name: String): UInt {
+        require(size>=0)
+        free.removeAll(address until address+size.toUInt())
+        if(name.isNotEmpty()) {
+            allocatedVariables[name] = when(datatype) {
+                in NumericDatatypes, DataType.BOOL -> VarAllocation(address, datatype, size)        // numerical variables in zeropage never have an initial value here because they are set in separate initializer assignments
+                DataType.STR -> VarAllocation(address, datatype, size)
+                in ArrayDatatypes -> VarAllocation(address, datatype, size)
+                else -> throw AssemblyError("invalid dt")
+            }
+        }
+        return address
+    }
+
+    private fun oneSeparateByteFree(address: UInt) = address in free && address-1u !in free && address+1u !in free
+    private fun sequentialFree(address: UInt, size: Int): Boolean {
+        require(size>0)
+        return free.containsAll((address until address+size.toUInt()).toList())
+    }
+
+    abstract fun allocateCx16VirtualRegisters()
+}
+
+
+// TODO: this class is not yet used
+class GoldenRam(options: CompilationOptions, val region: UIntRange): MemoryAllocator(options) {
+    private var nextLocation: UInt = region.first
+
+    override fun allocate(
+        name: String,
+        datatype: DataType,
+        numElements: Int?,
+        position: Position?,
+        errors: IErrorReporter): Result<VarAllocation, MemAllocationError> {
+
+        val size: Int =
+            when (datatype) {
+                in IntegerDatatypesWithBoolean -> options.compTarget.memorySize(datatype)
+                DataType.STR, in ArrayDatatypes  -> {
+                    options.compTarget.memorySize(datatype, numElements!!)
+                }
+                DataType.FLOAT -> {
+                    if (options.floats) {
+                        options.compTarget.memorySize(DataType.FLOAT)
+                    } else return Err(MemAllocationError("floating point option not enabled"))
+                }
+                else -> throw MemAllocationError("weird dt")
+            }
+
+        return if(nextLocation<=region.last && (region.last + 1u - nextLocation) >= size.toUInt()) {
+            val result = Ok(VarAllocation(nextLocation, datatype, size))
+            nextLocation += size.toUInt()
+            result
+        } else
+            Err(MemAllocationError("no more free space in Golden RAM to allocate $size sequential bytes"))
+    }
+}

codeCore/src/prog8/code/core/Operators.kt

@@ -0,0 +1,18 @@
+package prog8.code.core
+
+val AssociativeOperators = setOf("+", "*", "&", "|", "^", "==", "!=", "xor")       // note: and,or are no longer associative because of Shortcircuit/McCarthy evaluation
+val ComparisonOperators = setOf("==", "!=", "<", ">", "<=", ">=")
+val LogicalOperators = setOf("and", "or", "xor", "not", "in")
+val BitwiseOperators = setOf("&", "|", "^", "~")
+val PrefixOperators = setOf("+", "-", "~", "not")
+
+fun invertedComparisonOperator(operator: String) =
+    when (operator) {
+        "==" -> "!="
+        "!=" -> "=="
+        "<" -> ">="
+        ">" -> "<="
+        "<=" -> ">"
+        ">=" -> "<"
+        else -> null
+    }

codeCore/src/prog8/code/core/Position.kt

@@ -0,0 +1,27 @@
+package prog8.code.core
+
+import prog8.code.core.SourceCode.Companion.LIBRARYFILEPREFIX
+import java.nio.file.InvalidPathException
+import kotlin.io.path.Path
+import kotlin.io.path.absolute
+
+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}]"
+    fun toClickableStr(): String {
+        if(this===DUMMY)
+            return ""
+        if(file.startsWith(LIBRARYFILEPREFIX))
+            return "$file:$line:$startCol:"
+        return try {
+            val path = Path(file).absolute().normalize().toString()
+            "file://$path:$line:$startCol:"
+        } catch(x: InvalidPathException) {
+            // this can occur on Windows when the source origin contains "invalid" characters such as ':'
+            "file://$file:$line:$startCol:"
+        }
+    }
+
+    companion object {
+        val DUMMY = Position("~dummy~", 0, 0, 0)
+    }
+}

codeCore/src/prog8/code/core/RegisterOrStatusflag.kt

@@ -0,0 +1,3 @@
+package prog8.code.core
+
+data class RegisterOrStatusflag(val registerOrPair: RegisterOrPair?, val statusflag: Statusflag?)

codeCore/src/prog8/code/core/SourceCode.kt

@@ -0,0 +1,177 @@
+package prog8.code.core
+
+import java.io.File
+import java.io.IOException
+import java.nio.file.Path
+import java.text.Normalizer
+import kotlin.io.path.Path
+import kotlin.io.path.readText
+
+
+const val internedStringsModuleName = "prog8_interned_strings"
+
+
+/**
+ * Encapsulates - and ties together - actual source code (=text) and its [origin].
+ */
+sealed class SourceCode {
+
+    /**
+     * Whether this [SourceCode] instance was created as a [Resource]
+     */
+    abstract val isFromResources: Boolean
+
+    /**
+     * Whether this [SourceCode] instance was created as a [File]
+     */
+    abstract val isFromFilesystem: Boolean
+
+    /**
+     * The logical name of the source code unit. Usually the module's name.
+     */
+    abstract val name: String
+
+    /**
+     * Where this [SourceCode] instance came from.
+     * This can be one of the following:
+     * * a normal string representation of a [java.nio.file.Path], if it originates from a file (see [File])
+     * * `string:44c56085` if was created via [String]
+     * * `library:/x/y/z.ext` if it is a library file that was loaded from resources (see [Resource])
+     */
+    abstract val origin: String
+
+    /**
+     * The source code as plain string.
+     */
+    abstract val text: String
+
+    /**
+     * Printable representation, deliberately does NOT return the actual text.
+     */
+    final override fun toString() = "${this.javaClass.name}[${this.origin}]"
+
+    companion object {
+
+        /**
+         * filename prefix to designate library files that will be retreived from internal resources rather than disk
+         */
+        const val LIBRARYFILEPREFIX = "library:"
+        const val STRINGSOURCEPREFIX = "string:"
+        val curdir: Path = Path(".").toAbsolutePath()
+        fun relative(path: Path): Path = curdir.relativize(path.toAbsolutePath())
+        fun isRegularFilesystemPath(pathString: String) =
+            !(pathString.startsWith(LIBRARYFILEPREFIX) || pathString.startsWith(STRINGSOURCEPREFIX))
+
+        fun isLibraryResource(path: String) = path.startsWith(LIBRARYFILEPREFIX)
+    }
+
+    /**
+     * Turn a plain String into a [SourceCode] object.
+     * [origin] will be something like `string:44c56085`.
+     */
+    class Text(origText: String): SourceCode() {
+        override val text = origText.replace("\\R".toRegex(), "\n")      // normalize line endings
+        override val isFromResources = false
+        override val isFromFilesystem = false
+        override val origin = "$STRINGSOURCEPREFIX${System.identityHashCode(text).toString(16)}"
+        override val name = "<unnamed-text>"
+    }
+
+    /**
+     * Get [SourceCode] from the file represented by the specified Path.
+     * This immediately reads the file fully into memory.
+     *
+     * [origin] will be the given path in absolute and normalized form.
+     * @throws NoSuchFileException if the file does not exist
+     * @throws FileSystemException if the file cannot be read
+     */
+    class File(path: Path): SourceCode() {
+        override val text: String
+        override val origin: String
+        override val name: String
+        override val isFromResources = false
+        override val isFromFilesystem = true
+
+        init {
+            val normalized = path.normalize()
+            origin = relative(normalized).toString()
+            try {
+                val contents = Normalizer.normalize(normalized.readText(), Normalizer.Form.NFC)
+                text = contents.replace("\\R".toRegex(), "\n")      // normalize line endings
+                name = normalized.toFile().nameWithoutExtension
+            } catch (nfx: java.nio.file.NoSuchFileException) {
+                throw NoSuchFileException(normalized.toFile()).also { it.initCause(nfx) }
+            } catch (iox: IOException) {
+                throw FileSystemException(normalized.toFile()).also { it.initCause(iox) }
+            }
+        }
+    }
+
+    /**
+     * [origin]: `library:/x/y/z.p8` for a given `pathString` of "x/y/z.p8"
+     */
+    class Resource(pathString: String): SourceCode() {
+        private val normalized = "/" + Path(pathString).normalize().toMutableList().joinToString("/")
+
+        override val isFromResources = true
+        override val isFromFilesystem = false
+        override val origin = "$LIBRARYFILEPREFIX$normalized"
+        override val text: String
+        override val name: String
+
+        init {
+            val rscURL = object {}.javaClass.getResource(normalized)
+            if (rscURL == null) {
+                val rscRoot = object {}.javaClass.getResource("/")
+                throw NoSuchFileException(
+                    File(normalized),
+                    reason = "looked in resources rooted at $rscRoot"
+                )
+            }
+            val stream = object {}.javaClass.getResourceAsStream(normalized)
+            val contents = stream!!.reader().use { Normalizer.normalize(it.readText(), Normalizer.Form.NFC) }
+            text = contents.replace("\\R".toRegex(), "\n")      // normalize line endings
+            name = Path(pathString).toFile().nameWithoutExtension
+        }
+    }
+
+    /**
+     * SourceCode for internally generated nodes (usually Modules)
+     */
+    class Generated(override val name: String) : SourceCode() {
+        override val isFromResources: Boolean = false
+        override val isFromFilesystem: Boolean = false
+        override val origin: String = name
+        override val text: String = "<generated code node, no text representation>"
+    }
+}
+
+
+object SourceLineCache {
+    private val cache = mutableMapOf<String, List<String>>()
+
+    private fun getCachedFile(file: String): List<String> {
+        val existing = cache[file]
+        if(existing!=null)
+            return existing
+        if (SourceCode.isRegularFilesystemPath(file)) {
+            val source = SourceCode.File(Path(file))
+            cache[file] = source.text.split('\n', '\r').map { it.trim() }
+            return cache.getValue(file)
+        } else if(file.startsWith(SourceCode.LIBRARYFILEPREFIX)) {
+            val source = SourceCode.Resource(file.drop(SourceCode.LIBRARYFILEPREFIX.length))
+            cache[file] = source.text.split('\n', '\r').map { it.trim()}
+            return cache.getValue(file)
+        }
+        return emptyList()
+    }
+
+    fun retrieveLine(position: Position): String? {
+        if (position.line>0) {
+            val lines = getCachedFile(position.file)
+            if(lines.isNotEmpty())
+                return lines[position.line-1]
+        }
+        return null
+    }
+}

codeCore/src/prog8/code/optimize/Optimizer.kt

@@ -0,0 +1,258 @@
+package prog8.code.optimize
+
+import prog8.code.StRomSub
+import prog8.code.SymbolTable
+import prog8.code.ast.*
+import prog8.code.core.*
+
+
+fun optimizeIntermediateAst(program: PtProgram, options: CompilationOptions, st: SymbolTable, errors: IErrorReporter) {
+    if (!options.optimize)
+        return
+    while (errors.noErrors() &&
+        (optimizeCommonSubExpressions(program, errors)
+                + optimizeBitTest(program, options)
+                + optimizeAssignTargets(program, st, errors)) > 0
+    ) {
+        // keep rolling
+    }
+}
+
+
+private fun walkAst(root: PtNode, act: (node: PtNode, depth: Int) -> Boolean) {
+    fun recurse(node: PtNode, depth: Int) {
+        if(act(node, depth))
+            node.children.forEach { recurse(it, depth+1) }
+    }
+    recurse(root, 0)
+}
+
+
+private var tempVarCounter = 0
+
+private fun optimizeCommonSubExpressions(program: PtProgram, errors: IErrorReporter): Int {
+
+    fun extractableSubExpr(expr: PtExpression): Boolean {
+        if(expr is PtArrayIndexer && expr.index.isSimple())
+            return false
+        if (expr is PtMemoryByte && expr.address.isSimple())
+            return false
+
+        val result = if(expr is PtBinaryExpression)
+            expr.type !in ByteDatatypes ||
+            !(expr.left.isSimple() && expr.right.isSimple()) ||
+            (expr.operator !in LogicalOperators && expr.operator !in BitwiseOperators)
+        else if (expr is PtArrayIndexer && expr.type !in ByteDatatypes)
+            true
+        else
+            !expr.isSimple()
+        return result
+    }
+
+    // for each Binaryexpression, recurse to find a common subexpression pair therein.
+    val commons = mutableMapOf<PtBinaryExpression, Pair<PtExpression, PtExpression>>()
+    walkAst(program) { node: PtNode, depth: Int ->
+        if(node is PtBinaryExpression) {
+            val subExpressions = mutableListOf<PtExpression>()
+            walkAst(node.left) { subNode: PtNode, subDepth: Int ->
+                if (subNode is PtExpression) {
+                    if(extractableSubExpr(subNode)) subExpressions.add(subNode)
+                    true
+                } else false
+            }
+            walkAst(node.right) { subNode: PtNode, subDepth: Int ->
+                if (subNode is PtExpression) {
+                    if(extractableSubExpr(subNode)) subExpressions.add(subNode)
+                    true
+                } else false
+            }
+
+            outer@for (first in subExpressions) {
+                for (second in subExpressions) {
+                    if (first!==second && first isSameAs second) {
+                        commons[node] = first to second
+                        break@outer     // do only 1 replacement at a time per binaryexpression
+                    }
+                }
+            }
+            false
+        } else true
+    }
+
+    // replace common subexpressions by a temp variable that is assigned only once.
+    // TODO: check for commonalities across multiple separate expressions in the current scope, not only inside a single line
+    commons.forEach { binexpr, (occurrence1, occurrence2) ->
+        val (stmtContainer, stmt) = findContainingStatements(binexpr)
+        val occurrence1idx = occurrence1.parent.children.indexOf(occurrence1)
+        val occurrence2idx = occurrence2.parent.children.indexOf(occurrence2)
+        val containerScopedName = findScopeName(stmtContainer)
+        tempVarCounter++
+        val tempvarName = "prog8_subexprvar_$tempVarCounter"
+        // TODO: some tempvars could be reused, if they are from different lines
+
+        val datatype = occurrence1.type
+        val singleReplacement1 = PtIdentifier("$containerScopedName.$tempvarName", datatype, occurrence1.position)
+        val singleReplacement2 = PtIdentifier("$containerScopedName.$tempvarName", datatype, occurrence2.position)
+        occurrence1.parent.children[occurrence1idx] = singleReplacement1
+        singleReplacement1.parent = occurrence1.parent
+        occurrence2.parent.children[occurrence2idx] = singleReplacement2
+        singleReplacement2.parent = occurrence2.parent
+
+        val tempassign = PtAssignment(binexpr.position).also { assign ->
+            assign.add(PtAssignTarget(false, binexpr.position).also { tgt->
+                tgt.add(PtIdentifier("$containerScopedName.$tempvarName", datatype, binexpr.position))
+            })
+            assign.add(occurrence1)
+            occurrence1.parent = assign
+        }
+        stmtContainer.children.add(stmtContainer.children.indexOf(stmt), tempassign)
+        tempassign.parent = stmtContainer
+
+        val tempvar = PtVariable(tempvarName, datatype, ZeropageWish.NOT_IN_ZEROPAGE, null, null, binexpr.position)
+        stmtContainer.add(0, tempvar)
+        tempvar.parent = stmtContainer
+
+        // errors.info("common subexpressions replaced by a tempvar, maybe simplify the expression manually", binexpr.position)
+    }
+
+    return commons.size
+}
+
+
+private fun optimizeAssignTargets(program: PtProgram, st: SymbolTable, errors: IErrorReporter): Int {
+    var changes = 0
+    walkAst(program) { node: PtNode, depth: Int ->
+        if(node is PtAssignment) {
+            val value = node.value
+            val functionName = when(value) {
+                is PtBuiltinFunctionCall -> value.name
+                is PtFunctionCall -> value.name
+                else -> null
+            }
+            if(functionName!=null) {
+                val stNode = st.lookup(functionName)
+                if (stNode is StRomSub) {
+                    require(node.children.size==stNode.returns.size+1) {
+                        "number of targets must match return values"
+                    }
+                    node.children.zip(stNode.returns).withIndex().forEach { (index, xx) ->
+                        val target = xx.first as PtAssignTarget
+                        val returnedRegister = xx.second.register.registerOrPair
+                        if(returnedRegister!=null && !target.void && target.identifier!=null) {
+                            if(isSame(target.identifier!!, xx.second.type, returnedRegister)) {
+                                // output register is already identical to target register, so it can become void
+                                val voidTarget = PtAssignTarget(true, target.position)
+                                node.children[index] = voidTarget
+                                voidTarget.parent = node
+                                changes++
+                            }
+                        }
+                    }
+                }
+                if(node.children.dropLast(1).all { (it as PtAssignTarget).void }) {
+                    // all targets are now void, the whole assignment can be discarded and replaced by just a (void) call to the subroutine
+                    val index = node.parent.children.indexOf(node)
+                    val voidCall = PtFunctionCall(functionName, true, value.type, value.position)
+                    value.children.forEach { voidCall.add(it) }
+                    node.parent.children[index] = voidCall
+                    voidCall.parent = node.parent
+                    changes++
+                }
+            }
+        }
+        true
+    }
+    return changes
+}
+
+
+private fun optimizeBitTest(program: PtProgram, options: CompilationOptions): Int {
+    if(options.compTarget.machine.cpu == CpuType.VIRTUAL)
+        return 0        // the special bittest optimization is not yet valid for the IR
+
+    var changes = 0
+    var recurse = true
+    walkAst(program) { node: PtNode, depth: Int ->
+        if(node is PtIfElse) {
+            val condition = node.condition as? PtBinaryExpression
+            if(condition!=null && (condition.operator=="==" || condition.operator=="!=")) {
+                if(condition.right.asConstInteger()==0) {
+                    val and = condition.left as? PtBinaryExpression
+                    if(and != null && and.operator=="&" && and.type == DataType.UBYTE) {
+                        val variable = and.left as? PtIdentifier
+                        val bitmask = and.right.asConstInteger()
+                        if(variable!=null && variable.type in ByteDatatypes && (bitmask==128 || bitmask==64)) {
+                            val setOrNot = if(condition.operator=="!=") "set" else "notset"
+                            val index = node.parent.children.indexOf(node)
+                            val bittestCall = PtBuiltinFunctionCall("prog8_ifelse_bittest_$setOrNot", false, true, DataType.BOOL, node.condition.position)
+                            bittestCall.add(variable)
+                            if(bitmask==128)
+                                bittestCall.add(PtNumber(DataType.UBYTE, 7.0, and.right.position))
+                            else
+                                bittestCall.add(PtNumber(DataType.UBYTE, 6.0, and.right.position))
+                            val ifElse = PtIfElse(node.position)
+                            ifElse.add(bittestCall)
+                            ifElse.add(node.ifScope)
+                            if(node.hasElse())
+                                ifElse.add(node.elseScope)
+                            node.parent.children[index] = ifElse
+                            ifElse.parent = node.parent
+                            changes++
+                            recurse = false
+                        }
+                    }
+                }
+            }
+        }
+        recurse
+    }
+    return changes
+}
+
+
+internal fun isSame(identifier: PtIdentifier, type: DataType, returnedRegister: RegisterOrPair): Boolean {
+    if(returnedRegister in Cx16VirtualRegisters) {
+        val regname = returnedRegister.name.lowercase()
+        val identifierRegName = identifier.name.substringAfterLast('.')
+        /*
+            cx16.r?    UWORD
+            cx16.r?s   WORD
+            cx16.r?L   UBYTE
+            cx16.r?H   UBYTE
+            cx16.r?sL  BYTE
+            cx16.r?sH  BYTE
+         */
+        if(identifier.type in ByteDatatypes && type in ByteDatatypes) {
+            if(identifier.name.startsWith("cx16.$regname") && identifierRegName.startsWith(regname)) {
+                return identifierRegName.substring(2) in arrayOf("", "L", "sL")     // note: not the -H (msb) variants!
+            }
+        }
+        else if(identifier.type in WordDatatypes && type in WordDatatypes) {
+            if(identifier.name.startsWith("cx16.$regname") && identifierRegName.startsWith(regname)) {
+                return identifierRegName.substring(2) in arrayOf("", "s")
+            }
+        }
+    }
+    return false   // there are no identifiers directly corresponding to cpu registers
+}
+
+
+internal fun findScopeName(node: PtNode): String {
+    var parent=node
+    while(parent !is PtNamedNode)
+        parent = parent.parent
+    return parent.scopedName
+}
+
+
+internal fun findContainingStatements(node: PtNode): Pair<PtNode, PtNode> {      // returns (parentstatementcontainer, childstatement)
+    var parent = node.parent
+    var child = node
+    while(true) {
+        if(parent is IPtStatementContainer) {
+            return parent to child
+        }
+        child=parent
+        parent=parent.parent
+    }
+}

codeCore/src/prog8/code/target/AtariTarget.kt

@@ -0,0 +1,31 @@
+package prog8.code.target
+
+import prog8.code.core.*
+import prog8.code.target.atari.AtariMachineDefinition
+
+
+class AtariTarget: ICompilationTarget, IStringEncoding by Encoder, IMemSizer {
+    override val name = NAME
+    override val machine = AtariMachineDefinition()
+    override val defaultEncoding = Encoding.ATASCII
+
+    companion object {
+        const val NAME = "atari"
+    }
+
+    override fun memorySize(dt: DataType): Int {
+        return when(dt) {
+            in ByteDatatypesWithBoolean -> 1
+            in WordDatatypes, in PassByReferenceDatatypes -> 2
+            DataType.FLOAT -> machine.FLOAT_MEM_SIZE
+            else -> throw IllegalArgumentException("invalid datatype")
+        }
+    }
+
+    override fun memorySize(arrayDt: DataType, numElements: Int) =
+        if(arrayDt==DataType.UWORD)
+            numElements    // pointer to bytes.
+        else
+            memorySize(ArrayToElementTypes.getValue(arrayDt)) * numElements
+
+}

codeCore/src/prog8/code/target/C128Target.kt

@@ -0,0 +1,19 @@
+package prog8.code.target
+
+import prog8.code.core.Encoding
+import prog8.code.core.ICompilationTarget
+import prog8.code.core.IMemSizer
+import prog8.code.core.IStringEncoding
+import prog8.code.target.c128.C128MachineDefinition
+import prog8.code.target.cbm.CbmMemorySizer
+
+
+class C128Target: ICompilationTarget, IStringEncoding by Encoder, IMemSizer by CbmMemorySizer {
+    override val name = NAME
+    override val machine = C128MachineDefinition()
+    override val defaultEncoding = Encoding.PETSCII
+
+    companion object {
+        const val NAME = "c128"
+    }
+}

codeCore/src/prog8/code/target/C64Target.kt

@@ -0,0 +1,41 @@
+package prog8.code.target
+
+import prog8.code.core.Encoding
+import prog8.code.core.ICompilationTarget
+import prog8.code.core.IMemSizer
+import prog8.code.core.IStringEncoding
+import prog8.code.target.c64.C64MachineDefinition
+import prog8.code.target.cbm.CbmMemorySizer
+
+
+class C64Target: ICompilationTarget, IStringEncoding by Encoder, IMemSizer by CbmMemorySizer {
+    override val name = NAME
+    override val machine = C64MachineDefinition()
+    override val defaultEncoding = Encoding.PETSCII
+
+    companion object {
+        const val NAME = "c64"
+
+        fun viceMonListName(baseFilename: String) = "$baseFilename.vice-mon-list"
+    }
+}
+
+
+val CompilationTargets = listOf(
+    C64Target.NAME,
+    C128Target.NAME,
+    Cx16Target.NAME,
+    PETTarget.NAME,
+    AtariTarget.NAME,
+    VMTarget.NAME
+)
+
+fun getCompilationTargetByName(name: String) = when(name.lowercase()) {
+    C64Target.NAME -> C64Target()
+    C128Target.NAME -> C128Target()
+    Cx16Target.NAME -> Cx16Target()
+    PETTarget.NAME -> PETTarget()
+    AtariTarget.NAME -> AtariTarget()
+    VMTarget.NAME -> VMTarget()
+    else -> throw IllegalArgumentException("invalid compilation target")
+}

codeCore/src/prog8/code/target/Cx16Target.kt

@@ -0,0 +1,19 @@
+package prog8.code.target
+
+import prog8.code.core.Encoding
+import prog8.code.core.ICompilationTarget
+import prog8.code.core.IMemSizer
+import prog8.code.core.IStringEncoding
+import prog8.code.target.cbm.CbmMemorySizer
+import prog8.code.target.cx16.CX16MachineDefinition
+
+
+class Cx16Target: ICompilationTarget, IStringEncoding by Encoder, IMemSizer by CbmMemorySizer {
+    override val name = NAME
+    override val machine = CX16MachineDefinition()
+    override val defaultEncoding = Encoding.PETSCII
+
+    companion object {
+        const val NAME = "cx16"
+    }
+}

codeCore/src/prog8/code/target/Encoder.kt

@@ -0,0 +1,47 @@
+package prog8.code.target
+
+import com.github.michaelbull.result.fold
+import prog8.code.core.Encoding
+import prog8.code.core.IStringEncoding
+import prog8.code.core.InternalCompilerException
+import prog8.code.target.encodings.*
+
+
+object Encoder: IStringEncoding {
+    override val defaultEncoding: Encoding = Encoding.ISO
+
+    override fun encodeString(str: String, encoding: Encoding): List<UByte> {
+        val coded = when(encoding) {
+            Encoding.PETSCII -> PetsciiEncoding.encodePetscii(str, true)
+            Encoding.SCREENCODES -> PetsciiEncoding.encodeScreencode(str, true)
+            Encoding.ISO -> IsoEncoding.encode(str)
+            Encoding.ATASCII -> AtasciiEncoding.encode(str)
+            Encoding.ISO5 -> IsoCyrillicEncoding.encode(str)
+            Encoding.ISO16 -> IsoEasternEncoding.encode(str)
+            Encoding.CP437 -> Cp437Encoding.encode(str)
+            Encoding.KATAKANA -> KatakanaEncoding.encode(str)
+            else -> throw InternalCompilerException("unsupported encoding $encoding")
+        }
+        return coded.fold(
+            failure = { throw it },
+            success = { it }
+        )
+    }
+    override fun decodeString(bytes: Iterable<UByte>, encoding: Encoding): String {
+        val decoded = when(encoding) {
+            Encoding.PETSCII -> PetsciiEncoding.decodePetscii(bytes, true)
+            Encoding.SCREENCODES -> PetsciiEncoding.decodeScreencode(bytes, true)
+            Encoding.ISO -> IsoEncoding.decode(bytes)
+            Encoding.ATASCII -> AtasciiEncoding.decode(bytes)
+            Encoding.ISO5 -> IsoCyrillicEncoding.decode(bytes)
+            Encoding.ISO16 -> IsoEasternEncoding.decode(bytes)
+            Encoding.CP437 -> Cp437Encoding.decode(bytes)
+            Encoding.KATAKANA -> KatakanaEncoding.decode(bytes)
+            else -> throw InternalCompilerException("unsupported encoding $encoding")
+        }
+        return decoded.fold(
+            failure = { throw it },
+            success = { it }
+        )
+    }
+}

codeCore/src/prog8/code/target/PETTarget.kt

@@ -0,0 +1,19 @@
+package prog8.code.target
+
+import prog8.code.core.Encoding
+import prog8.code.core.ICompilationTarget
+import prog8.code.core.IMemSizer
+import prog8.code.core.IStringEncoding
+import prog8.code.target.cbm.CbmMemorySizer
+import prog8.code.target.pet.PETMachineDefinition
+
+
+class PETTarget: ICompilationTarget, IStringEncoding by Encoder, IMemSizer by CbmMemorySizer {
+    override val name = NAME
+    override val machine = PETMachineDefinition()
+    override val defaultEncoding = Encoding.PETSCII
+
+    companion object {
+        const val NAME = "pet32"
+    }
+}

codeCore/src/prog8/code/target/VMTarget.kt

@@ -0,0 +1,29 @@
+package prog8.code.target
+
+import prog8.code.core.*
+import prog8.code.target.virtual.VirtualMachineDefinition
+
+class VMTarget: ICompilationTarget, IStringEncoding by Encoder, IMemSizer {
+    override val name = NAME
+    override val machine = VirtualMachineDefinition()
+    override val defaultEncoding = Encoding.ISO
+
+    companion object {
+        const val NAME = "virtual"
+    }
+
+    override fun memorySize(dt: DataType): Int {
+        return when(dt) {
+            in ByteDatatypesWithBoolean -> 1
+            in WordDatatypes, in PassByReferenceDatatypes -> 2
+            DataType.FLOAT -> machine.FLOAT_MEM_SIZE
+            else -> throw IllegalArgumentException("invalid datatype")
+        }
+    }
+
+    override fun memorySize(arrayDt: DataType, numElements: Int) =
+        if(arrayDt==DataType.UWORD)
+            numElements    // pointer to bytes.
+        else
+            memorySize(ArrayToElementTypes.getValue(arrayDt)) * numElements
+}

codeCore/src/prog8/code/target/atari/AtariMachineDefinition.kt

@@ -0,0 +1,60 @@
+package prog8.code.target.atari
+
+import prog8.code.core.*
+import java.nio.file.Path
+
+
+class AtariMachineDefinition: IMachineDefinition {
+
+    override val cpu = CpuType.CPU6502
+
+    override val FLOAT_MAX_POSITIVE = 9.999999999e97
+    override val FLOAT_MAX_NEGATIVE = -9.999999999e97
+    override val FLOAT_MEM_SIZE = 6
+    override val PROGRAM_LOAD_ADDRESS = 0x2000u
+
+    override val BSSHIGHRAM_START = 0u    // TODO
+    override val BSSHIGHRAM_END = 0u      // TODO
+    override val BSSGOLDENRAM_START = 0u  // TODO
+    override val BSSGOLDENRAM_END = 0u    // TODO
+
+    override lateinit var zeropage: Zeropage
+    override lateinit var golden: GoldenRam
+
+    override fun getFloatAsmBytes(num: Number) = TODO("atari float asm bytes from number")
+    override fun convertFloatToBytes(num: Double): List<UByte> = TODO("atari float to bytes")
+    override fun convertBytesToFloat(bytes: List<UByte>): Double = TODO("atari bytes to float")
+
+    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
+        val emulatorName: String
+        val cmdline: List<String>
+        when(selectedEmulator) {
+            1 -> {
+                emulatorName = "atari800"
+                cmdline = listOf(emulatorName, "-xl", "-xl-rev", "2", "-nobasic", "-run", "${programNameWithPath}.xex")
+            }
+            2 -> {
+                emulatorName = "altirra"
+                cmdline = listOf("Altirra64.exe", "${programNameWithPath.normalize()}.xex")
+            }
+            else -> {
+                System.err.println("Atari target only supports atari800 and altirra emulators.")
+                return
+            }
+        }
+
+        // TODO monlist?
+
+        println("\nStarting Atari800XL emulator $emulatorName...")
+        val processb = ProcessBuilder(cmdline).inheritIO()
+        val process: Process = processb.start()
+        process.waitFor()
+    }
+
+    override fun isIOAddress(address: UInt): Boolean = address==0u || address==1u || address in 0xd000u..0xdfffu        // TODO
+
+    override fun initializeMemoryAreas(compilerOptions: CompilationOptions) {
+        zeropage = AtariZeropage(compilerOptions)
+        golden = GoldenRam(compilerOptions, UIntRange.EMPTY)
+    }
+}

codeCore/src/prog8/code/target/atari/AtariZeropage.kt

@@ -0,0 +1,57 @@
+package prog8.code.target.atari
+
+import prog8.code.core.CompilationOptions
+import prog8.code.core.InternalCompilerException
+import prog8.code.core.Zeropage
+import prog8.code.core.ZeropageType
+
+class AtariZeropage(options: CompilationOptions) : Zeropage(options) {
+
+    override val SCRATCH_B1 = 0xcbu      // temp storage for a single byte
+    override val SCRATCH_REG = 0xccu     // temp storage for a register, must be B1+1
+    override val SCRATCH_W1 = 0xcdu      // temp storage 1 for a word  $cd+$ce
+    override val SCRATCH_W2 = 0xcfu      // temp storage 2 for a word  $cf+$d0        TODO is $d0 okay to use?
+
+    init {
+        if (options.floats) {
+            throw InternalCompilerException("Atari target doesn't yet support floating point routines")
+        }
+
+        if (options.floats && options.zeropage !in arrayOf(
+                ZeropageType.FLOATSAFE,
+                ZeropageType.BASICSAFE,
+                ZeropageType.DONTUSE
+            ))
+            throw InternalCompilerException("when floats are enabled, zero page type should be 'floatsafe' or 'basicsafe' or 'dontuse'")
+
+        when (options.zeropage) {
+            ZeropageType.FULL -> {
+                // TODO all atari usable zero page locations, except the ones used by the system's IRQ routine
+                free.addAll(0x00u..0xffu)
+                // TODO atari  free.removeAll(setOf(0xa0u, 0xa1u, 0xa2u, 0x91u, 0xc0u, 0xc5u, 0xcbu, 0xf5u, 0xf6u))        // these are updated by IRQ
+            }
+            ZeropageType.KERNALSAFE -> {
+                free.addAll(0x80u..0xffu)       // TODO
+            }
+            ZeropageType.BASICSAFE,
+            ZeropageType.FLOATSAFE -> {
+                free.addAll(0x80u..0xffu)       // TODO
+                free.removeAll(0xd4u .. 0xefu)      // floating point storage
+            }
+            ZeropageType.DONTUSE -> {
+                free.clear()  // don't use zeropage at all
+            }
+        }
+
+        val distinctFree = free.distinct()
+        free.clear()
+        free.addAll(distinctFree)
+
+        removeReservedFromFreePool()
+        retainAllowed()
+    }
+
+    override fun allocateCx16VirtualRegisters() {
+        TODO("Not known if atari can put the virtual regs in ZP")
+    }
+}

codeCore/src/prog8/code/target/c128/C128MachineDefinition.kt

@@ -0,0 +1,60 @@
+package prog8.code.target.c128
+
+import prog8.code.core.*
+import prog8.code.target.C64Target
+import prog8.code.target.cbm.Mflpt5
+import java.nio.file.Path
+
+
+class C128MachineDefinition: IMachineDefinition {
+
+    override val cpu = CpuType.CPU6502
+
+    override val FLOAT_MAX_POSITIVE = Mflpt5.FLOAT_MAX_POSITIVE
+    override val FLOAT_MAX_NEGATIVE = Mflpt5.FLOAT_MAX_NEGATIVE
+    override val FLOAT_MEM_SIZE = Mflpt5.FLOAT_MEM_SIZE
+    override val PROGRAM_LOAD_ADDRESS = 0x1c01u
+
+    override val BSSHIGHRAM_START = 0u    // TODO
+    override val BSSHIGHRAM_END = 0u      // TODO
+    override val BSSGOLDENRAM_START = 0u  // TODO
+    override val BSSGOLDENRAM_END = 0u    // TODO
+
+    override lateinit var zeropage: Zeropage
+    override lateinit var golden: GoldenRam
+
+    override fun getFloatAsmBytes(num: Number) = Mflpt5.fromNumber(num).makeFloatFillAsm()
+
+    override fun convertFloatToBytes(num: Double): List<UByte> {
+        val m5 = Mflpt5.fromNumber(num)
+        return listOf(m5.b0, m5.b1, m5.b2, m5.b3, m5.b4)
+    }
+
+    override fun convertBytesToFloat(bytes: List<UByte>): Double {
+        require(bytes.size==5) { "need 5 bytes" }
+        val m5 = Mflpt5(bytes[0], bytes[1], bytes[2], bytes[3], bytes[4])
+        return m5.toDouble()
+    }
+
+    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
+        if(selectedEmulator!=1) {
+            System.err.println("The c128 target only supports the main emulator (Vice).")
+            return
+        }
+
+        println("\nStarting C-128 emulator x128...")
+        val viceMonlist = C64Target.viceMonListName(programNameWithPath.toString())
+        val cmdline = listOf("x128", "-silent", "-moncommands", viceMonlist,
+                "-autostartprgmode", "1", "-autostart-warp", "-autostart", "${programNameWithPath}.prg")
+        val processb = ProcessBuilder(cmdline).inheritIO()
+        val process: Process = processb.start()
+        process.waitFor()
+    }
+
+    override fun isIOAddress(address: UInt): Boolean = address==0u || address==1u || address in 0xd000u..0xdfffu
+
+    override fun initializeMemoryAreas(compilerOptions: CompilationOptions) {
+        zeropage = C128Zeropage(compilerOptions)
+        golden = GoldenRam(compilerOptions, UIntRange.EMPTY)    // TODO does the c128 have some of this somewhere?
+    }
+}

codeCore/src/prog8/code/target/c128/C128Zeropage.kt

@@ -0,0 +1,78 @@
+package prog8.code.target.c128
+
+import prog8.code.core.CompilationOptions
+import prog8.code.core.InternalCompilerException
+import prog8.code.core.Zeropage
+import prog8.code.core.ZeropageType
+
+
+// reference: "Mapping the C128" zero page chapter.
+
+class C128Zeropage(options: CompilationOptions) : Zeropage(options) {
+
+    override val SCRATCH_B1 = 0x74u      // temp storage for a single byte
+    override val SCRATCH_REG = 0x75u     // temp storage for a register, must be B1+1
+    override val SCRATCH_W1 = 0xfbu      // temp storage 1 for a word  $fb+$fc
+    override val SCRATCH_W2 = 0xfdu      // temp storage 2 for a word  $fd+$fe
+
+    init {
+        if (options.floats) {
+            throw InternalCompilerException("C128 target doesn't yet support floating point routines")
+            // note: in git commit labeled 'c128: remove floats module' the floats.p8 and floats.asm files are removed,
+            //       they could be retrieved again at a later time if the compiler somehow *does* store the fp variables in bank1.
+        }
+
+        if (options.floats && options.zeropage !in arrayOf(
+                ZeropageType.FLOATSAFE,
+                ZeropageType.BASICSAFE,
+                ZeropageType.DONTUSE
+            ))
+            throw InternalCompilerException("when floats are enabled, zero page type should be 'floatsafe' or 'basicsafe' or 'dontuse'")
+
+        when (options.zeropage) {
+            ZeropageType.FULL -> {
+                // $00/$01 are data port IO registers, // $02-$09 are storage locations for JSRFAR and such
+                free.addAll(0x0au..0xffu)
+                free.removeAll(listOf(0x90u, 0x91u, 0xa0u, 0xa1u, 0xa2u, 0xc0u, 0xccu, 0xcdu, 0xd0u, 0xd1u, 0xd2u, 0xd3u, 0xd4u, 0xd5u, 0xf7u))        // these are updated/used by IRQ
+            }
+            ZeropageType.KERNALSAFE -> {
+                free.addAll(0x0au..0x8fu)       // BASIC variables
+                free.addAll(listOf(0x92u, 0x96u, 0x9bu, 0x9cu, 0x9eu, 0x9fu, 0xa4u, 0xa7u, 0xa8u, 0xa9u, 0xaau, 0xabu,
+                    0xb0u, 0xb1u, 0xb4u, 0xb5u, 0xb6u))
+            }
+            ZeropageType.FLOATSAFE,
+            ZeropageType.BASICSAFE -> {
+                free.addAll(listOf(0x0bu, 0x0cu, 0x0du, 0x0eu, 0x0fu, 0x10u, 0x11u, 0x12u, 0x16u, 0x17u, 0x18u, 0x19u, 0x1au))
+                free.addAll(0x1bu..0x23u)
+                free.addAll(listOf(0x3fu, 0x40u, 0x41u, 0x42u, 0x43u, 0x44u, 0x47u, 0x48u, 0x49u, 0x4au, 0x4bu, 0x4cu, 0x4fu,
+                    0x55u, 0x56u, 0x57u, 0x58u,
+                    0x74u, 0x75u, 0x78u, 0x80u, 0x83u, 0x87u, 0x88u, 0x89u, 0x8au, 0x8bu, 0x8cu, 0x8du, 0x8eu, 0x8fu,
+                    0x92u, 0x96u, 0x9bu, 0x9cu, 0x9eu, 0x9fu, 0xa4u, 0xa7u, 0xa8u, 0xa9u, 0xaau, 0xabu,
+                    0xb0u, 0xb1u, 0xb4u, 0xb5u, 0xb6u
+                ))
+
+                // if(options.zeropage==ZeropageType.BASICSAFE) {
+                    // can also clobber the FP locations (unconditionally, because the C128 target doesn't support floating point calculations in prog8 at this time0
+                    free.addAll(listOf(0x14u, 0x28u, 0x29u, 0x2au, 0x2bu, 0x2cu,
+                        0x50u, 0x51u, 0x52u, 0x53u, 0x54u, 0x59u, 0x5au, 0x5bu, 0x5cu, 0x5du, 0x5eu, 0x5fu, 0x60u, 0x61u, 0x62u,
+                        0x63u, 0x64u, 0x65u, 0x66u, 0x67u, 0x68u,
+                        0x6au, 0x6bu, 0x6cu, 0x6du, 0x6eu, 0x6fu, 0x71u))
+                // }
+            }
+            ZeropageType.DONTUSE -> {
+                free.clear()  // don't use zeropage at all
+            }
+        }
+
+        val distinctFree = free.distinct()
+        free.clear()
+        free.addAll(distinctFree)
+
+        removeReservedFromFreePool()
+        retainAllowed()
+    }
+
+    override fun allocateCx16VirtualRegisters() {
+        TODO("Not known if C128 can put the virtual regs in ZP")
+    }
+}

codeCore/src/prog8/code/target/c64/C64MachineDefinition.kt

@@ -0,0 +1,70 @@
+package prog8.code.target.c64
+
+import prog8.code.core.*
+import prog8.code.target.C64Target
+import prog8.code.target.cbm.Mflpt5
+import java.io.IOException
+import java.nio.file.Path
+
+
+class C64MachineDefinition: IMachineDefinition {
+
+    override val cpu = CpuType.CPU6502
+
+    override val FLOAT_MAX_POSITIVE = Mflpt5.FLOAT_MAX_POSITIVE
+    override val FLOAT_MAX_NEGATIVE = Mflpt5.FLOAT_MAX_NEGATIVE
+    override val FLOAT_MEM_SIZE = Mflpt5.FLOAT_MEM_SIZE
+    override val PROGRAM_LOAD_ADDRESS = 0x0801u
+
+    override val BSSHIGHRAM_START = 0xc000u
+    override val BSSHIGHRAM_END = 0xcfffu
+    override val BSSGOLDENRAM_START = 0u
+    override val BSSGOLDENRAM_END = 0u
+
+    override lateinit var zeropage: Zeropage
+    override lateinit var golden: GoldenRam
+
+    override fun getFloatAsmBytes(num: Number) = Mflpt5.fromNumber(num).makeFloatFillAsm()
+
+    override fun convertFloatToBytes(num: Double): List<UByte> {
+        val m5 = Mflpt5.fromNumber(num)
+        return listOf(m5.b0, m5.b1, m5.b2, m5.b3, m5.b4)
+    }
+
+    override fun convertBytesToFloat(bytes: List<UByte>): Double {
+        require(bytes.size==5) { "need 5 bytes" }
+        val m5 = Mflpt5(bytes[0], bytes[1], bytes[2], bytes[3], bytes[4])
+        return m5.toDouble()
+    }
+
+    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
+        if(selectedEmulator!=1) {
+            System.err.println("The c64 target only supports the main emulator (Vice).")
+            return
+        }
+
+        for(emulator in listOf("x64sc", "x64")) {
+            println("\nStarting C-64 emulator $emulator...")
+            val viceMonlist = C64Target.viceMonListName(programNameWithPath.toString())
+            val cmdline = listOf(emulator, "-silent", "-moncommands", viceMonlist,
+                    "-autostartprgmode", "1", "-autostart-warp", "-autostart", "${programNameWithPath}.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
+        }
+    }
+
+    override fun isIOAddress(address: UInt): Boolean = address==0u || address==1u || address in 0xd000u..0xdfffu
+
+    override fun initializeMemoryAreas(compilerOptions: CompilationOptions) {
+        zeropage = C64Zeropage(compilerOptions)
+        golden = GoldenRam(compilerOptions, 0xc000u until 0xd000u)
+    }
+
+}

codeCore/src/prog8/code/target/c64/C64Zeropage.kt

@@ -0,0 +1,98 @@
+package prog8.code.target.c64
+
+import prog8.code.core.*
+
+
+class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
+
+    override val SCRATCH_B1 = 0x02u      // temp storage for a single byte
+    override val SCRATCH_REG = 0x03u     // temp storage for a register, must be B1+1
+    override val SCRATCH_W1 = 0xfbu      // temp storage 1 for a word  $fb+$fc
+    override val SCRATCH_W2 = 0xfdu      // temp storage 2 for a word  $fd+$fe
+
+
+    init {
+        if (options.floats && options.zeropage !in arrayOf(
+                ZeropageType.FLOATSAFE,
+                ZeropageType.BASICSAFE,
+                ZeropageType.DONTUSE
+            ))
+            throw InternalCompilerException("when floats are enabled, zero page type should be 'floatsafe' or 'basicsafe' or 'dontuse'")
+
+        if (options.zeropage == ZeropageType.FULL) {
+            free.addAll(0x02u..0xffu)
+            free.removeAll(setOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_W1, SCRATCH_W1+1u, SCRATCH_W2, SCRATCH_W2+1u))
+            free.removeAll(setOf(0xa0u, 0xa1u, 0xa2u, 0x91u, 0xc0u, 0xc5u, 0xcbu, 0xf5u, 0xf6u))        // these are updated by IRQ
+        } else {
+            if (options.zeropage == ZeropageType.KERNALSAFE || options.zeropage == ZeropageType.FLOATSAFE) {
+                free.addAll(listOf(
+                        0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+                        0x10, 0x11, 0x12, 0x13, 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 'kernal work storage area'
+                ).map{it.toUInt()})
+            }
+
+            if (options.zeropage == ZeropageType.FLOATSAFE) {
+                // remove the zeropage locations used for floating point operations from the free list
+                free.removeAll(listOf(
+                        0x03, 0x04, 0x05, 0x06, 0x10, 0x11, 0x12,
+                        0x22, 0x23, 0x24, 0x25, 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, 0xff
+                ).map{it.toUInt()})
+            }
+
+            if(options.zeropage != ZeropageType.DONTUSE) {
+                // add the free Zp addresses
+                // these are valid for the C-64 but allow BASIC to keep running fully *as long as you don't use tape I/O*
+                free.addAll(listOf(0x02, 0x03, 0x04, 0x05, 0x06, 0x0a, 0x0e,
+                        0x92, 0x96, 0x9b, 0x9c, 0x9e, 0x9f, 0xa6,
+                        0xb0, 0xb1, 0xbe, 0xbf, 0xf9).map{it.toUInt()})
+            } else {
+                // don't use the zeropage at all
+                free.clear()
+            }
+        }
+
+        val distinctFree = free.distinct()
+        free.clear()
+        free.addAll(distinctFree)
+
+        removeReservedFromFreePool()
+
+        if(options.zeropage==ZeropageType.FULL || options.zeropage==ZeropageType.KERNALSAFE) {
+            // in these cases there is enough space on the zero page to stick the cx16 virtual registers in there as well.
+            allocateCx16VirtualRegisters()
+        }
+
+        retainAllowed()
+    }
+
+    override fun allocateCx16VirtualRegisters() {
+        // Note: the 16 virtual registers R0-R15 are not regular allocated variables, they're *memory mapped* elsewhere to fixed addresses.
+        // However, to be able for the compiler to "see" them as zero page variables, we have to register them here as well.
+        // This is important because the compiler sometimes treats ZP variables more efficiently (for example if it's a pointer)
+        // The base addres is $04.  Unfortunately it cannot be the same as on the Commander X16 ($02).
+        for(reg in 0..15) {
+            allocatedVariables["cx16.r${reg}"]   = VarAllocation((4+reg*2).toUInt(), DataType.UWORD, 2)       // cx16.r0 .. cx16.r15
+            allocatedVariables["cx16.r${reg}s"]  = VarAllocation((4+reg*2).toUInt(), DataType.WORD, 2)        // cx16.r0s .. cx16.r15s
+            allocatedVariables["cx16.r${reg}L"]  = VarAllocation((4+reg*2).toUInt(), DataType.UBYTE, 1)       // cx16.r0L .. cx16.r15L
+            allocatedVariables["cx16.r${reg}H"]  = VarAllocation((5+reg*2).toUInt(), DataType.UBYTE, 1)       // cx16.r0H .. cx16.r15H
+            allocatedVariables["cx16.r${reg}sL"] = VarAllocation((4+reg*2).toUInt(), DataType.BYTE, 1)        // cx16.r0sL .. cx16.r15sL
+            allocatedVariables["cx16.r${reg}sH"] = VarAllocation((5+reg*2).toUInt(), DataType.BYTE, 1)        // cx16.r0sH .. cx16.r15sH
+            free.remove((4+reg*2).toUInt())
+            free.remove((5+reg*2).toUInt())
+        }
+    }
+}

codeCore/src/prog8/code/target/cbm/CbmMemorySizer.kt

@@ -0,0 +1,21 @@
+package prog8.code.target.cbm
+
+import prog8.code.core.*
+
+
+internal object CbmMemorySizer: IMemSizer {
+    override fun memorySize(dt: DataType): Int {
+        return when(dt) {
+            in ByteDatatypesWithBoolean -> 1
+            in WordDatatypes, in PassByReferenceDatatypes -> 2
+            DataType.FLOAT -> Mflpt5.FLOAT_MEM_SIZE
+            else -> throw IllegalArgumentException("invalid datatype")
+        }
+    }
+
+    override fun memorySize(arrayDt: DataType, numElements: Int) =
+        if(arrayDt==DataType.UWORD)
+            numElements    // pointer to bytes.
+        else
+            memorySize(ArrayToElementTypes.getValue(arrayDt)) * numElements
+}

codeCore/src/prog8/code/target/cbm/Mflpt5.kt

@@ -0,0 +1,77 @@
+package prog8.code.target.cbm
+
+import prog8.code.core.InternalCompilerException
+import kotlin.math.absoluteValue
+import kotlin.math.pow
+
+
+data class Mflpt5(val b0: UByte, val b1: UByte, val b2: UByte, val b3: UByte, val b4: UByte) {
+
+    companion object {
+        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 FLOAT_MEM_SIZE = 5
+
+        val zero = Mflpt5(0u, 0u, 0u, 0u, 0u)
+        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 InternalCompilerException("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 InternalCompilerException("floating point overflow: $this")
+                exponent == 0 -> zero
+                else -> {
+                    val mantLong = mantissa.toLong()
+                    Mflpt5(
+                        exponent.toUByte(),
+                        (mantLong.and(0x7f000000L) ushr 24).or(sign).toUByte(),
+                        (mantLong.and(0x00ff0000L) ushr 16).toUByte(),
+                        (mantLong.and(0x0000ff00L) ushr 8).toUByte(),
+                        (mantLong.and(0x000000ffL)).toUByte()
+                    )
+                }
+            }
+        }
+    }
+
+    fun toDouble(): Double {
+        if (this == zero) return 0.0
+        val exp = b0.toInt() - 128
+        val sign = (b1.toInt() and 0x80) > 0
+        val number = 0x80000000L.or(b1.toLong() shl 24).or(b2.toLong() shl 16).or(b3.toLong() shl 8).or(b4.toLong())
+        val result = number.toDouble() * (2.0).pow(exp) / 0x100000000
+        return if (sign) -result else result
+    }
+
+    fun makeFloatFillAsm(): String {
+        val b0 = "$" + b0.toString(16).padStart(2, '0')
+        val b1 = "$" + b1.toString(16).padStart(2, '0')
+        val b2 = "$" + b2.toString(16).padStart(2, '0')
+        val b3 = "$" + b3.toString(16).padStart(2, '0')
+        val b4 = "$" + b4.toString(16).padStart(2, '0')
+        return "$b0, $b1, $b2, $b3, $b4"
+    }
+}

codeCore/src/prog8/code/target/cx16/CX16MachineDefinition.kt

@@ -0,0 +1,73 @@
+package prog8.code.target.cx16
+
+import prog8.code.core.*
+import prog8.code.target.C64Target
+import prog8.code.target.cbm.Mflpt5
+import java.nio.file.Path
+
+
+class CX16MachineDefinition: IMachineDefinition {
+
+    override val cpu = CpuType.CPU65c02
+
+    override val FLOAT_MAX_POSITIVE = Mflpt5.FLOAT_MAX_POSITIVE
+    override val FLOAT_MAX_NEGATIVE = Mflpt5.FLOAT_MAX_NEGATIVE
+    override val FLOAT_MEM_SIZE = Mflpt5.FLOAT_MEM_SIZE
+    override val PROGRAM_LOAD_ADDRESS = 0x0801u
+
+    override val BSSHIGHRAM_START = 0xa000u     // hiram bank 1, 8Kb, assumed to be active
+    override val BSSHIGHRAM_END = 0xbfffu       // Rom starts at $c000
+    override val BSSGOLDENRAM_START = 0x0400u
+    override val BSSGOLDENRAM_END = 0x07ffu
+
+    override lateinit var zeropage: Zeropage
+    override lateinit var golden: GoldenRam
+
+    override fun getFloatAsmBytes(num: Number) = Mflpt5.fromNumber(num).makeFloatFillAsm()
+
+    override fun convertFloatToBytes(num: Double): List<UByte> {
+        val m5 = Mflpt5.fromNumber(num)
+        return listOf(m5.b0, m5.b1, m5.b2, m5.b3, m5.b4)
+    }
+
+    override fun convertBytesToFloat(bytes: List<UByte>): Double {
+        require(bytes.size==5) { "need 5 bytes" }
+        val m5 = Mflpt5(bytes[0], bytes[1], bytes[2], bytes[3], bytes[4])
+        return m5.toDouble()
+    }
+
+    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
+        val emulator: String
+        val extraArgs: List<String>
+
+        when(selectedEmulator) {
+            1 -> {
+                emulator = "x16emu"
+                extraArgs = listOf("-debug")
+            }
+            2 -> {
+                emulator = "box16"
+                extraArgs = listOf("-sym", C64Target.viceMonListName(programNameWithPath.toString()))
+            }
+            else -> {
+                System.err.println("Cx16 target only supports x16emu and box16 emulators.")
+                return
+            }
+        }
+
+        println("\nStarting Commander X16 emulator $emulator...")
+        val cmdline = listOf(emulator, "-scale", "2", "-rtc", "-run", "-prg", "${programNameWithPath}.prg") + extraArgs
+        val processb = ProcessBuilder(cmdline).inheritIO()
+        processb.environment()["PULSE_LATENCY_MSEC"] = "10"
+        val process: Process = processb.start()
+        process.waitFor()
+    }
+
+    override fun isIOAddress(address: UInt): Boolean = address==0u || address==1u || address in 0x9f00u..0x9fffu
+
+    override fun initializeMemoryAreas(compilerOptions: CompilationOptions) {
+        zeropage = CX16Zeropage(compilerOptions)
+        golden = GoldenRam(compilerOptions, 0x0400u until 0x0800u)
+    }
+
+}

codeCore/src/prog8/code/target/cx16/CX16Zeropage.kt

@@ -0,0 +1,68 @@
+package prog8.code.target.cx16
+
+import prog8.code.core.*
+
+
+class CX16Zeropage(options: CompilationOptions) : Zeropage(options) {
+
+    override val SCRATCH_B1 = 0x7au      // temp storage for a single byte
+    override val SCRATCH_REG = 0x7bu     // temp storage for a register, must be B1+1
+    override val SCRATCH_W1 = 0x7cu      // temp storage 1 for a word  $7c+$7d
+    override val SCRATCH_W2 = 0x7eu      // temp storage 2 for a word  $7e+$7f
+
+
+    init {
+        if (options.floats && options.zeropage !in arrayOf(
+                ZeropageType.FLOATSAFE,
+                ZeropageType.BASICSAFE,
+                ZeropageType.DONTUSE
+            ))
+            throw InternalCompilerException("when floats are enabled, zero page type should be 'floatsafe' or 'basicsafe' or 'dontuse'")
+
+        // the addresses 0x02 to 0x21 (inclusive) are taken for sixteen virtual 16-bit api registers.
+
+        synchronized(this) {
+            when (options.zeropage) {
+                ZeropageType.FULL -> {
+                    free.addAll(0x22u..0xffu)
+                }
+                ZeropageType.KERNALSAFE -> {
+                    free.addAll(0x22u..0x7fu)
+                    free.addAll(0xa9u..0xffu)
+                }
+                ZeropageType.FLOATSAFE -> {
+                    free.addAll(0x22u..0x7fu)
+                    free.addAll(0xd4u..0xffu)
+                }
+                ZeropageType.BASICSAFE -> {
+                    free.addAll(0x22u..0x7fu)
+                }
+                ZeropageType.DONTUSE -> {
+                    free.clear() // don't use zeropage at all
+                }
+            }
+
+            val distinctFree = free.distinct()
+            free.clear()
+            free.addAll(distinctFree)
+
+            removeReservedFromFreePool()
+            allocateCx16VirtualRegisters()
+            retainAllowed()
+        }
+    }
+
+    override fun allocateCx16VirtualRegisters() {
+        // Note: the 16 virtual registers R0-R15 are not regular allocated variables, they're *memory mapped* elsewhere to fixed addresses.
+        // However, to be able for the compiler to "see" them as zero page variables, we have to register them here as well.
+        // This is important because the compiler sometimes treats ZP variables more efficiently (for example if it's a pointer)
+        for(reg in 0..15) {
+            allocatedVariables["cx16.r${reg}"]   = VarAllocation((2+reg*2).toUInt(), DataType.UWORD, 2)       // cx16.r0 .. cx16.r15
+            allocatedVariables["cx16.r${reg}s"]  = VarAllocation((2+reg*2).toUInt(), DataType.WORD, 2)        // cx16.r0s .. cx16.r15s
+            allocatedVariables["cx16.r${reg}L"]  = VarAllocation((2+reg*2).toUInt(), DataType.UBYTE, 1)       // cx16.r0L .. cx16.r15L
+            allocatedVariables["cx16.r${reg}H"]  = VarAllocation((3+reg*2).toUInt(), DataType.UBYTE, 1)       // cx16.r0H .. cx16.r15H
+            allocatedVariables["cx16.r${reg}sL"] = VarAllocation((2+reg*2).toUInt(), DataType.BYTE, 1)        // cx16.r0sL .. cx16.r15sL
+            allocatedVariables["cx16.r${reg}sH"] = VarAllocation((3+reg*2).toUInt(), DataType.BYTE, 1)        // cx16.r0sH .. cx16.r15sH
+        }
+    }
+}

codeCore/src/prog8/code/target/encodings/AtasciiEncoding.kt

@@ -0,0 +1,214 @@
+package prog8.code.target.encodings
+
+import com.github.michaelbull.result.Ok
+import com.github.michaelbull.result.Result
+import java.io.CharConversionException
+
+object AtasciiEncoding {
+
+    private val decodeTable: CharArray = charArrayOf(
+        // $00
+        '♥',
+        '├',
+        '\uf130',    //  🮇    0x02 -> RIGHT ONE QUARTER BLOCK (CUS)
+        '┘',
+        '┤',
+        '┐',
+        '╱',
+        '╲',
+        '◢',
+        '▗',
+        '◣',
+        '▝',
+        '▘',
+        '\uf132',    //  🮂    0x1d -> UPPER ONE QUARTER BLOCK (CUS)
+        '▂',
+        '▖',
+
+        // $10
+     	'♣',
+        '┌',
+        '─',
+        '┼',
+        '•',
+        '▄',
+        '▎',
+        '┬',
+        '┴',
+        '▌',
+        '└',
+        '\u001b',           // $1b = escape
+        '\ufffe',           // UNDEFINED CHAR.   $1c = cursor up
+        '\ufffe',           // UNDEFINED CHAR.   $1d = cursor down
+        '\ufffe',           // UNDEFINED CHAR.   $1e = cursor left
+        '\ufffe',           // UNDEFINED CHAR.   $1f = cursor right
+
+        // $20
+        ' ',
+        '!',
+        '"',
+        '#',
+        '$',
+        '%',
+        '&',
+        '\'',
+        '(',
+        ')',
+        '*',
+        '+',
+        ',',
+        '-',
+        '.',
+        '/',
+
+        // $30
+     	'0',
+        '1',
+        '2',
+        '3',
+        '4',
+        '5',
+        '6',
+        '7',
+        '8',
+        '9',
+        ':',
+        ';',
+        '<',
+        '=',
+        '>',
+        '?',
+
+        // $40
+     	'@',
+        'A',
+        'B',
+        'C',
+        'D',
+        'E',
+        'F',
+        'G',
+        'H',
+        'I',
+        'J',
+        'K',
+        'L',
+        'M',
+        'N',
+        'O',
+
+        // $50
+        'P',
+        'Q',
+        'R',
+        'S',
+        'T',
+        'U',
+        'V',
+        'W',
+        'X',
+        'Y',
+        'Z',
+        '[',
+        '\\',
+        ']',
+        '^',
+        '_',
+
+        // $60
+        '♦',
+        'a',
+        'b',
+        'c',
+        'd',
+        'e',
+        'f',
+        'g',
+        'h',
+        'i',
+        'j',
+        'k',
+        'l',
+        'm',
+        'n',
+        'o',
+
+        // $70
+        'p',
+        'q',
+        'r',
+        's',
+        't',
+        'u',
+        'v',
+        'w',
+        'x',
+        'y',
+        'z',
+        '♠',
+        '|',
+        '\u000c',    //       $7d -> FORM FEED (CLEAR SCREEN)
+        '\u0008',    //       $7e -> BACKSPACE
+        '\u0009',    //       $7f -> TAB
+
+        // $80-$ff are reversed video characters + various special characters.
+        '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe',
+        '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe',
+        // $90
+        '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe',
+        '\ufffe',
+        '\ufffe',
+        '\ufffe',
+        '\n',               // $9b -> EOL/RETURN
+        '\ufffe',           // UNDEFINED   $9c = DELETE LINE
+        '\ufffe',           // UNDEFINED   $9d = INSERT LINE
+        '\ufffe',           // UNDEFINED   $9e = CLEAR TAB STOP
+        '\ufffe',           // UNDEFINED   $9f = SET TAB STOP
+        // $a0
+        '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe',
+        '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe',
+        // $b0
+        '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe',
+        '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe',
+        // $c0
+        '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe',
+        '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe',
+        // $d0
+        '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe',
+        '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe',
+        // $e0
+        '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe',
+        '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe',
+        // $f0
+        '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe', '\ufffe',
+        '\ufffe',
+        '\ufffe',
+        '\ufffe',
+        '\ufffe',
+        '\ufffe',
+        '\u0007',           // $fd = bell/beep
+        '\u007f',           // $fe = DELETE
+        '\ufffe'            // UNDEFINED     $ff = INSERT
+    )
+
+    private val encodeTable = decodeTable.withIndex().associate{it.value to it.index}
+
+
+    fun encode(str: String): Result<List<UByte>, CharConversionException> {
+        val mapped = str.map { chr ->
+            when (chr) {
+                '\u0000' -> 0u
+                in '\u8000'..'\u80ff' -> {
+                    // special case: take the lower 8 bit hex value directly
+                    (chr.code - 0x8000).toUByte()
+                }
+                else -> encodeTable.getValue(chr).toUByte()
+            }
+        }
+        return Ok(mapped)
+    }
+
+    fun decode(bytes: Iterable<UByte>): Result<String, CharConversionException> {
+        return Ok(bytes.map { decodeTable[it.toInt()] }.joinToString(""))
+    }
+}

codeCore/src/prog8/code/target/encodings/Cp437Encoding.kt

@@ -0,0 +1,69 @@
+package prog8.code.target.encodings
+
+import com.github.michaelbull.result.Err
+import com.github.michaelbull.result.Ok
+import com.github.michaelbull.result.Result
+import java.io.CharConversionException
+import java.nio.charset.Charset
+
+object Cp437Encoding {
+    val charset: Charset = Charset.forName("IBM437")
+
+    fun encode(str: String): Result<List<UByte>, CharConversionException> {
+        return try {
+            val mapped = str.map { chr ->
+                when (chr) {
+                    '\u0000' -> 0u
+                    '\u00a0' -> 255u
+                    '☺' -> 1u
+                    '☻' -> 2u
+                    '♥' -> 3u
+                    '♦' -> 4u
+                    '♣' -> 5u
+                    '♠' -> 6u
+                    '•' -> 7u
+                    '◘' -> 8u
+                    '○' -> 9u
+                    '◙' -> 10u
+                    '♂' -> 11u
+                    '♀' -> 12u
+                    '♪' -> 13u
+                    '♫' -> 14u
+                    '☼' -> 15u
+                    '►' -> 16u
+                    '◄' -> 17u
+                    '↕' -> 18u
+                    '‼' -> 19u
+                    '¶' -> 20u
+                    '§' -> 21u
+                    '▬' -> 22u
+                    '↨' -> 23u
+                    '↑' -> 24u
+                    '↓' -> 25u
+                    '→' -> 26u
+                    '←' -> 27u
+                    '∟' -> 28u
+                    '↔' -> 29u
+                    '▲' -> 30u
+                    '▼' -> 31u
+                    in '\u8000'..'\u80ff' -> {
+                        // special case: take the lower 8 bit hex value directly
+                        (chr.code - 0x8000).toUByte()
+                    }
+                    else -> charset.encode(chr.toString())[0].toUByte()
+                }
+            }
+            Ok(mapped)
+        } catch (ce: CharConversionException) {
+            Err(ce)
+        }
+    }
+
+    fun decode(bytes: Iterable<UByte>): Result<String, CharConversionException> {
+        return try {
+            Ok(String(bytes.map { it.toByte() }.toByteArray(), charset))
+        } catch (ce: CharConversionException) {
+            Err(ce)
+        }
+    }
+}

codeCore/src/prog8/code/target/encodings/IsoEncoding.kt

@@ -0,0 +1,42 @@
+package prog8.code.target.encodings
+
+import com.github.michaelbull.result.Err
+import com.github.michaelbull.result.Ok
+import com.github.michaelbull.result.Result
+import java.io.CharConversionException
+import java.nio.charset.Charset
+
+open class IsoEncodingBase(charsetName: String) {
+    val charset: Charset = Charset.forName(charsetName)
+
+    fun encode(str: String): Result<List<UByte>, CharConversionException> {
+        return try {
+            val mapped = str.map { chr ->
+                when (chr) {
+                    '\u0000' -> 0u
+                    in '\u8000'..'\u80ff' -> {
+                        // special case: take the lower 8 bit hex value directly
+                        (chr.code - 0x8000).toUByte()
+                    }
+                    else -> charset.encode(chr.toString())[0].toUByte()
+                }
+            }
+            Ok(mapped)
+        } catch (ce: CharConversionException) {
+            Err(ce)
+        }
+    }
+
+    fun decode(bytes: Iterable<UByte>): Result<String, CharConversionException> {
+        return try {
+            Ok(String(bytes.map { it.toByte() }.toByteArray(), charset))
+        } catch (ce: CharConversionException) {
+            Err(ce)
+        }
+    }
+}
+
+
+object IsoEncoding: IsoEncodingBase("ISO-8859-15")
+object IsoCyrillicEncoding: IsoEncodingBase("ISO-8859-5")
+object IsoEasternEncoding: IsoEncodingBase("ISO-8859-16")

codeCore/src/prog8/code/target/encodings/KatakanaEncoding.kt

@@ -0,0 +1,122 @@
+package prog8.code.target.encodings
+
+import com.github.michaelbull.result.Err
+import com.github.michaelbull.result.Ok
+import com.github.michaelbull.result.Result
+import java.io.CharConversionException
+import java.nio.charset.Charset
+
+
+object JapaneseCharacterConverter {
+    // adapted from https://github.com/raminduw/Japanese-Character-Converter
+
+    private val ZENKAKU_KATAKANA = charArrayOf(
+        'ァ', 'ア', 'ィ', 'イ', 'ゥ',
+        'ウ', 'ェ', 'エ', 'ォ', 'オ', 'カ', 'ガ', 'キ', 'ギ', 'ク', 'グ', 'ケ', 'ゲ',
+        'コ', 'ゴ', 'サ', 'ザ', 'シ', 'ジ', 'ス', 'ズ', 'セ', 'ゼ', 'ソ', 'ゾ', 'タ',
+        'ダ', 'チ', 'ヂ', 'ッ', 'ツ', 'ヅ', 'テ', 'デ', 'ト', 'ド', 'ナ', 'ニ', 'ヌ',
+        'ネ', 'ノ', 'ハ', 'バ', 'パ', 'ヒ', 'ビ', 'ピ', 'フ', 'ブ', 'プ', 'ヘ', 'ベ',
+        'ペ', 'ホ', 'ボ', 'ポ', 'マ', 'ミ', 'ム', 'メ', 'モ', 'ャ', 'ヤ', 'ュ', 'ユ',
+        'ョ', 'ヨ', 'ラ', 'リ', 'ル', 'レ', 'ロ', 'ヮ', 'ワ', 'ヰ', 'ヱ', 'ヲ', 'ン',
+        'ヴ', 'ヵ', 'ヶ'
+    )
+
+    private val HANKAKU_HIRAGANA = charArrayOf(
+        'ぁ', 'あ', 'ぃ', 'い', 'ぅ', 'う', 'ぇ', 'え',
+        'ぉ', 'お', 'か', 'が', 'き', 'ぎ', 'く', 'ぐ',
+        'け', 'げ', 'こ', 'ご', 'さ', 'ざ', 'し', 'じ',
+        'す', 'ず', 'せ', 'ぜ', 'そ', 'ぞ', 'た', 'だ',
+        'ち', 'ぢ', 'っ', 'つ', 'づ', 'て', 'で', 'と',
+        'ど', 'な', 'に', 'ぬ', 'ね', 'の', 'は', 'ば',
+        'ぱ', 'ひ', 'び', 'ぴ', 'ふ', 'ぶ', 'ぷ', 'へ',
+        'べ', 'ぺ', 'ほ', 'ぼ', 'ぽ', 'ま', 'み', 'む',
+        'め', 'も', 'ゃ', 'や', 'ゅ', 'ゆ', 'ょ', 'よ',
+        'ら', 'り', 'る', 'れ', 'ろ', 'ゎ', 'わ', 'ゐ',
+        'ゑ', 'を', 'ん', 'ゔ', 'ゕ', 'ゖ'
+    )
+
+    private val HANKAKU_KATAKANA = arrayOf(
+        "ｧ", "ｱ", "ｨ", "ｲ", "ｩ",
+        "ｳ", "ｪ", "ｴ", "ｫ", "ｵ", "ｶ", "ｶﾞ", "ｷ", "ｷﾞ", "ｸ", "ｸﾞ", "ｹ",
+        "ｹﾞ", "ｺ", "ｺﾞ", "ｻ", "ｻﾞ", "ｼ", "ｼﾞ", "ｽ", "ｽﾞ", "ｾ", "ｾﾞ", "ｿ",
+        "ｿﾞ", "ﾀ", "ﾀﾞ", "ﾁ", "ﾁﾞ", "ｯ", "ﾂ", "ﾂﾞ", "ﾃ", "ﾃﾞ", "ﾄ", "ﾄﾞ",
+        "ﾅ", "ﾆ", "ﾇ", "ﾈ", "ﾉ", "ﾊ", "ﾊﾞ", "ﾊﾟ", "ﾋ", "ﾋﾞ", "ﾋﾟ", "ﾌ",
+        "ﾌﾞ", "ﾌﾟ", "ﾍ", "ﾍﾞ", "ﾍﾟ", "ﾎ", "ﾎﾞ", "ﾎﾟ", "ﾏ", "ﾐ", "ﾑ", "ﾒ",
+        "ﾓ", "ｬ", "ﾔ", "ｭ", "ﾕ", "ｮ", "ﾖ", "ﾗ", "ﾘ", "ﾙ", "ﾚ", "ﾛ", "ﾜ",
+        "ﾜ", "ｲ", "ｴ", "ｦ", "ﾝ", "ｳﾞ", "ｶ", "ｹ"
+    )
+
+    private val ZENKAKU_KATAKANA_FIRST_CHAR_CODE = ZENKAKU_KATAKANA.first().code
+    private val HANKAKU_HIRAGANA_FIRST_CHAR_CODE = HANKAKU_HIRAGANA.first().code
+
+    private fun zenkakuKatakanaToHankakuKatakana(c: Char): String = if (c in ZENKAKU_KATAKANA) HANKAKU_KATAKANA[c.code - ZENKAKU_KATAKANA_FIRST_CHAR_CODE] else c.toString()
+    private fun hankakuKatakanaToZenkakuKatakana(c: Char): Char = if (c in HANKAKU_HIRAGANA) ZENKAKU_KATAKANA[c.code - HANKAKU_HIRAGANA_FIRST_CHAR_CODE] else c
+
+    fun zenkakuKatakanaToHankakuKatakana(s: String): String = buildString {
+        for (element in s) {
+            val converted = hankakuKatakanaToZenkakuKatakana(element)
+            val convertedChar = zenkakuKatakanaToHankakuKatakana(converted)
+            append(convertedChar)
+        }
+    }
+}
+
+object KatakanaEncoding {
+    val charset: Charset = Charset.forName("JIS_X0201")
+
+    fun encode(str: String): Result<List<UByte>, CharConversionException> {
+        return try {
+            val mapped = str.map { chr ->
+                when (chr) {
+
+                    '\u0000' -> 0u
+                    '\u00a0' -> 0xa0u // $a0 isn't technically a part of JIS X 0201 spec, and so we need to handle this ourselves
+
+                    '♥' -> 0xe3u
+                    '♦' -> 0xe4u
+                    '♣' -> 0xe5u
+                    '♠' -> 0xe6u
+
+                    '大' -> 0xeau
+                    '中' -> 0xebu
+                    '小' -> 0xecu
+                    '百' -> 0xedu
+                    '千' -> 0xeeu
+                    '万' -> 0xefu
+                    '♪' -> 0xf0u
+                    '土' -> 0xf1u
+                    '金' -> 0xf2u
+                    '木' -> 0xf3u
+                    '水' -> 0xf4u
+                    '火' -> 0xf5u
+                    '月' -> 0xf6u
+                    '日' -> 0xf7u
+                    '時' -> 0xf8u
+                    '分' -> 0xf9u
+                    '秒' -> 0xfau
+                    '年' -> 0xfbu
+                    '円' -> 0xfcu
+                    '人' -> 0xfdu
+                    '生' -> 0xfeu
+                    '〒' -> 0xffu
+                    in '\u8000'..'\u80ff' -> {
+                        // special case: take the lower 8 bit hex value directly
+                        (chr.code - 0x8000).toUByte()
+                    }
+                    else -> charset.encode(chr.toString())[0].toUByte()
+                }
+            }
+            Ok(mapped)
+        } catch (ce: CharConversionException) {
+            Err(ce)
+        }
+    }
+
+    fun decode(bytes: Iterable<UByte>): Result<String, CharConversionException> {
+        return try {
+            Ok(String(bytes.map { it.toByte() }.toByteArray(), charset))
+        } catch (ce: CharConversionException) {
+            Err(ce)
+        }
+    }
+}

codeCore/src/prog8/code/target/pet/PETMachineDefinition.kt

@@ -0,0 +1,61 @@
+package prog8.code.target.pet
+
+import prog8.code.core.*
+import prog8.code.target.C64Target
+import prog8.code.target.cbm.Mflpt5
+import java.nio.file.Path
+
+
+class PETMachineDefinition: IMachineDefinition {
+
+    override val cpu = CpuType.CPU6502
+
+    override val FLOAT_MAX_POSITIVE = Mflpt5.FLOAT_MAX_POSITIVE
+    override val FLOAT_MAX_NEGATIVE = Mflpt5.FLOAT_MAX_NEGATIVE
+    override val FLOAT_MEM_SIZE = Mflpt5.FLOAT_MEM_SIZE
+    override val PROGRAM_LOAD_ADDRESS = 0x0401u
+
+    override val BSSHIGHRAM_START = 0u
+    override val BSSHIGHRAM_END = 0u
+    override val BSSGOLDENRAM_START = 0u
+    override val BSSGOLDENRAM_END = 0u
+
+    override lateinit var zeropage: Zeropage
+    override lateinit var golden: GoldenRam
+
+    override fun getFloatAsmBytes(num: Number) = Mflpt5.fromNumber(num).makeFloatFillAsm()
+
+    override fun convertFloatToBytes(num: Double): List<UByte> {
+        val m5 = Mflpt5.fromNumber(num)
+        return listOf(m5.b0, m5.b1, m5.b2, m5.b3, m5.b4)
+    }
+
+    override fun convertBytesToFloat(bytes: List<UByte>): Double {
+        require(bytes.size==5) { "need 5 bytes" }
+        val m5 = Mflpt5(bytes[0], bytes[1], bytes[2], bytes[3], bytes[4])
+        return m5.toDouble()
+    }
+
+    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
+        if(selectedEmulator!=1) {
+            System.err.println("The pet target only supports the main emulator (Vice).")
+            return
+        }
+
+        println("\nStarting PET emulator...")
+        val viceMonlist = C64Target.viceMonListName(programNameWithPath.toString())
+        val cmdline = listOf("xpet", "-model", "4032", "-ramsize", "32", "-videosize", "40", "-silent", "-moncommands", viceMonlist,
+                "-autostartprgmode", "1", "-autostart-warp", "-autostart", "${programNameWithPath}.prg")
+        val processb = ProcessBuilder(cmdline).inheritIO()
+        val process=processb.start()
+        process.waitFor()
+    }
+
+    override fun isIOAddress(address: UInt): Boolean = address in 0xe800u..0xe8ffu
+
+    override fun initializeMemoryAreas(compilerOptions: CompilationOptions) {
+        zeropage = PETZeropage(compilerOptions)
+        // there's no golden ram.
+    }
+
+}

codeCore/src/prog8/code/target/pet/PETZeropage.kt

@@ -0,0 +1,59 @@
+package prog8.code.target.pet
+
+import prog8.code.core.CompilationOptions
+import prog8.code.core.InternalCompilerException
+import prog8.code.core.Zeropage
+import prog8.code.core.ZeropageType
+
+
+// reference: http://www.zimmers.net/cbmpics/cbm/PETx/petmem.txt
+
+class PETZeropage(options: CompilationOptions) : Zeropage(options) {
+
+    override val SCRATCH_B1 = 0xb3u      // temp storage for a single byte
+    override val SCRATCH_REG = 0xb4u     // temp storage for a register, must be B1+1
+    override val SCRATCH_W1 = 0xb6u      // temp storage 1 for a word
+    override val SCRATCH_W2 = 0xb8u      // temp storage 2 for a word
+
+    init {
+        if (options.floats) {
+            throw InternalCompilerException("PET target doesn't yet support floating point routines")
+        }
+
+        if (options.floats && options.zeropage !in arrayOf(
+                ZeropageType.FLOATSAFE,
+                ZeropageType.BASICSAFE,
+                ZeropageType.DONTUSE
+            ))
+            throw InternalCompilerException("when floats are enabled, zero page type should be 'floatsafe' or 'basicsafe' or 'dontuse'")
+
+        when (options.zeropage) {
+            ZeropageType.FULL -> {
+                free.addAll(0x00u..0xffu)
+                free.removeAll(listOf(0x8du, 0x8eu, 0x8fu, 0x97u, 0x98u, 0x99u, 0x9au, 0x9bu, 0x9eu, 0xa7u, 0xa8u, 0xa9u, 0xaau))        // these are updated/used by IRQ
+            }
+            ZeropageType.KERNALSAFE -> {
+                free.addAll(0x00u..0xffu)
+                free.removeAll(listOf(0x8du, 0x8eu, 0x8fu, 0x97u, 0x98u, 0x99u, 0x9au, 0x9bu, 0x9eu, 0xa7u, 0xa8u, 0xa9u, 0xaau))        // these are updated/used by IRQ
+            }
+            ZeropageType.FLOATSAFE,
+            ZeropageType.BASICSAFE -> {
+                free.addAll(0xb3u..0xbau)       // TODO more?
+            }
+            ZeropageType.DONTUSE -> {
+                free.clear()  // don't use zeropage at all
+            }
+        }
+
+        val distinctFree = free.distinct()
+        free.clear()
+        free.addAll(distinctFree)
+
+        removeReservedFromFreePool()
+        retainAllowed()
+    }
+
+    override fun allocateCx16VirtualRegisters() {
+        TODO("Not known if PET can put the virtual regs in ZP")
+    }
+}

codeCore/src/prog8/code/target/virtual/VirtualMachineDefinition.kt

@@ -0,0 +1,91 @@
+package prog8.code.target.virtual
+
+import prog8.code.core.*
+import java.nio.file.Path
+import kotlin.io.path.isReadable
+import kotlin.io.path.name
+import kotlin.io.path.readText
+
+class VirtualMachineDefinition: IMachineDefinition {
+
+    override val cpu = CpuType.VIRTUAL
+
+    override val FLOAT_MAX_POSITIVE = Float.MAX_VALUE.toDouble()
+    override val FLOAT_MAX_NEGATIVE = -Float.MAX_VALUE.toDouble()
+    override val FLOAT_MEM_SIZE = 8             // 64-bits double
+    override val PROGRAM_LOAD_ADDRESS = 0u      // not actually used
+
+    override val BSSHIGHRAM_START = 0u          // not actually used
+    override val BSSHIGHRAM_END = 0u            // not actually used
+    override val BSSGOLDENRAM_START = 0u        // not actually used
+    override val BSSGOLDENRAM_END = 0u          // not actually used
+    override lateinit var zeropage: Zeropage    // not actually used
+    override lateinit var golden: GoldenRam     // not actually used
+
+    override fun getFloatAsmBytes(num: Number): String {
+        // little endian binary representation
+        val bits = num.toDouble().toBits().toULong()
+        val hexStr = bits.toString(16).padStart(16, '0')
+        val parts = hexStr.chunked(2).map { "\$" + it }
+        return parts.joinToString(", ")
+    }
+
+    override fun convertFloatToBytes(num: Double): List<UByte> {
+        val bits = num.toBits().toULong()
+        val hexStr = bits.toString(16).padStart(16, '0')
+        val parts = hexStr.chunked(2).map { it.toInt(16).toUByte() }
+        return parts
+    }
+
+    override fun convertBytesToFloat(bytes: List<UByte>): Double {
+        require(bytes.size==8) { "need 8 bytes" }
+        val b0 = bytes[0].toLong() shl (8*7)
+        val b1 = bytes[1].toLong() shl (8*6)
+        val b2 = bytes[2].toLong() shl (8*5)
+        val b3 = bytes[3].toLong() shl (8*4)
+        val b4 = bytes[4].toLong() shl (8*3)
+        val b5 = bytes[5].toLong() shl (8*2)
+        val b6 = bytes[6].toLong() shl (8*1)
+        val b7 = bytes[7].toLong() shl (8*0)
+        return Double.fromBits(b0 or b1 or b2 or b3 or b4 or b5 or b6 or b7)
+    }
+
+    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
+        println("\nStarting Virtual Machine...")
+        // to not have external module dependencies in our own module, we launch the virtual machine via reflection
+        val vm = Class.forName("prog8.vm.VmRunner").getDeclaredConstructor().newInstance() as IVirtualMachineRunner
+        val filename = programNameWithPath.name
+        if(programNameWithPath.isReadable()) {
+            vm.runProgram(programNameWithPath.readText())
+        } else {
+            val withExt = programNameWithPath.resolveSibling("$filename.p8ir")
+            if(withExt.isReadable())
+                vm.runProgram(withExt.readText())
+            else
+                throw NoSuchFileException(withExt.toFile(), reason="not a .p8ir file")
+        }
+    }
+
+    override fun isIOAddress(address: UInt): Boolean = false
+
+    override fun initializeMemoryAreas(compilerOptions: CompilationOptions) {
+        zeropage = VirtualZeropage(compilerOptions)
+    }
+}
+
+interface IVirtualMachineRunner {
+    fun runProgram(irSource: String)
+}
+
+private class VirtualZeropage(options: CompilationOptions): Zeropage(options) {
+    override val SCRATCH_B1: UInt
+        get() = throw IllegalStateException("virtual shouldn't use this zeropage variable")
+    override val SCRATCH_REG: UInt
+        get() = throw IllegalStateException("virtual shouldn't use this zeropage variable")
+    override val SCRATCH_W1: UInt
+        get() = throw IllegalStateException("virtual shouldn't use this zeropage variable")
+    override val SCRATCH_W2: UInt
+        get() = throw IllegalStateException("virtual shouldn't use this zeropage variable")
+
+    override fun allocateCx16VirtualRegisters() { /* there is no actual zero page in this target to allocate thing in */ }
+}

codeGenCpu6502/build.gradle

@@ -0,0 +1,62 @@
+plugins {
+    id 'java'
+    id 'application'
+    id "org.jetbrains.kotlin.jvm"
+}
+
+java {
+    targetCompatibility = JavaLanguageVersion.of(javaVersion)
+    sourceCompatibility = JavaLanguageVersion.of(javaVersion)
+}
+
+compileKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+compileTestKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+dependencies {
+    implementation project(':codeCore')
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
+    // implementation "org.jetbrains.kotlin:kotlin-reflect"
+    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:2.0.0"
+
+    testImplementation 'io.kotest:kotest-runner-junit5-jvm:5.9.1'
+    testImplementation 'org.junit.jupiter:junit-jupiter:5.9.2'
+    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
+}
+
+sourceSets {
+    main {
+        java {
+            srcDir "${project.projectDir}/src"
+        }
+        resources {
+            srcDir "${project.projectDir}/res"
+        }
+    }
+    test {
+        java {
+            srcDir "${project.projectDir}/test"
+        }
+    }
+}
+
+test {
+    // Enable JUnit 5 (Gradle 4.6+).
+    useJUnitPlatform()
+
+    // Always run tests, even when nothing changed.
+    dependsOn 'cleanTest'
+
+    // Show test results.
+    testLogging {
+        events "skipped", "failed"
+    }
+}

codeGenCpu6502/codeGenCpu6502.iml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/test" isTestSource="true" />
+      <excludeFolder url="file://$MODULE_DIR$/build" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="KotlinJavaRuntime" level="project" />
+    <orderEntry type="module" module-name="codeCore" />
+    <orderEntry type="library" name="michael.bull.kotlin.result.jvm" level="project" />
+    <orderEntry type="library" name="io.kotest.assertions.core.jvm" level="project" />
+    <orderEntry type="library" name="io.kotest.runner.junit5.jvm" level="project" />
+  </component>
+</module>

codeGenCpu6502/src/prog8/codegen/cpu6502/AsmOptimizer.kt

@@ -0,0 +1,748 @@
+package prog8.codegen.cpu6502
+
+import prog8.code.StConstant
+import prog8.code.StMemVar
+import prog8.code.SymbolTable
+import prog8.code.core.IMachineDefinition
+
+
+// note: see https://wiki.nesdev.org/w/index.php/6502_assembly_optimisations
+
+
+internal fun optimizeAssembly(lines: MutableList<String>, machine: IMachineDefinition, symbolTable: SymbolTable): Int {
+
+    var numberOfOptimizations = 0
+
+    var linesByFour = getLinesBy(lines, 4)
+
+    var mods = optimizeIncDec(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    mods = optimizeStoreLoadSame(linesByFour, machine, symbolTable)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    mods = optimizeJsrRtsAndOtherCombinations(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    mods = optimizeUselessPushPopStack(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    mods = optimizeUnneededTempvarInAdd(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    mods = optimizeTSBtoRegularOr(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    var linesByFourteen = getLinesBy(lines, 14)
+    mods = optimizeSameAssignments(linesByFourteen, machine, symbolTable)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFourteen = getLinesBy(lines, 14)
+        numberOfOptimizations++
+    }
+
+    mods = optimizeSamePointerIndexingAndUselessBeq(linesByFourteen)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFourteen = getLinesBy(lines, 14)
+        numberOfOptimizations++
+    }
+
+    return numberOfOptimizations
+}
+
+private fun String.isBranch() = this.startsWith("b")
+private fun String.isStoreReg() = this.startsWith("sta") || this.startsWith("sty") || this.startsWith("stx")
+private fun String.isStoreRegOrZero() = this.isStoreReg() || this.startsWith("stz")
+private fun String.isLoadReg() = this.startsWith("lda") || this.startsWith("ldy") || this.startsWith("ldx")
+
+private class Modification(val lineIndex: Int, val remove: Boolean, val replacement: String?, val removeLabel: Boolean=false)
+
+private fun apply(modifications: List<Modification>, lines: MutableList<String>) {
+    for (modification in modifications.sortedBy { it.lineIndex }.reversed()) {
+        if(modification.remove) {
+            if(modification.removeLabel)
+                lines.removeAt(modification.lineIndex)
+            else {
+                val line = lines[modification.lineIndex]
+                if (line.length < 2 || line[0] == ';' || line.trimStart()[0] == ';')
+                    lines.removeAt(modification.lineIndex)
+                else if (haslabel(line)) {
+                    val label = keeplabel(line)
+                    if (label.isNotEmpty())
+                        lines[modification.lineIndex] = label
+                    else
+                        lines.removeAt(modification.lineIndex)
+                } else lines.removeAt(modification.lineIndex)
+            }
+        }
+        else
+            lines[modification.lineIndex] = modification.replacement!!
+    }
+}
+
+private fun haslabel(line: String): Boolean {
+    return line.length>1 && line[0]!=';' && (!line[0].isWhitespace() || ':' in line)
+}
+
+private fun keeplabel(line: String): String {
+    if(':' in line)
+        return line.substringBefore(':') + ':'
+    val splits = line.split('\t', ' ', limit=2)
+    return if(splits.size>1) splits[0] + ':' else ""
+}
+
+private fun getLinesBy(lines: MutableList<String>, windowSize: Int) =
+// all lines (that aren't empty or comments) in sliding windows of certain size
+        lines.asSequence().withIndex().filter { it.value.isNotBlank() && !it.value.trimStart().startsWith(';') }.windowed(windowSize, partialWindows = false)
+
+private fun optimizeSameAssignments(
+    linesByFourteen: Sequence<List<IndexedValue<String>>>,
+    machine: IMachineDefinition,
+    symbolTable: SymbolTable
+): List<Modification> {
+
+    // Optimize sequential assignments of the same value to various targets (bytes, words, floats)
+    // the float one is the one that requires 2*7=14 lines of code to check...
+    // The better place to do this is in the Compiler instead and never create these types of assembly, but hey
+
+    val mods = mutableListOf<Modification>()
+    for (lines in linesByFourteen) {
+        val first = lines[0].value.trimStart()
+        val second = lines[1].value.trimStart()
+        val third = lines[2].value.trimStart()
+        val fourth = lines[3].value.trimStart()
+        val fifth = lines[4].value.trimStart()
+        val sixth = lines[5].value.trimStart()
+        val seventh = lines[6].value.trimStart()
+        val eighth = lines[7].value.trimStart()
+
+        if(first.startsWith("lda") && second.startsWith("ldy") && third.startsWith("sta") && fourth.startsWith("sty") &&
+                fifth.startsWith("lda") && sixth.startsWith("ldy") && seventh.startsWith("sta") && eighth.startsWith("sty")) {
+            val firstvalue = first.substring(4)
+            val secondvalue = second.substring(4)
+            val thirdvalue = fifth.substring(4)
+            val fourthvalue = sixth.substring(4)
+            if(firstvalue==thirdvalue && secondvalue==fourthvalue) {
+                // lda/ldy   sta/sty   twice the same word -->  remove second lda/ldy pair (fifth and sixth lines)
+                val address1 = getAddressArg(first, symbolTable)
+                val address2 = getAddressArg(second, symbolTable)
+                if(address1==null || address2==null || (!machine.isIOAddress(address1) && !machine.isIOAddress(address2))) {
+                    mods.add(Modification(lines[4].index, true, null))
+                    mods.add(Modification(lines[5].index, true, null))
+                }
+            }
+        }
+
+        if(first.startsWith("lda") && second.startsWith("sta") && third.startsWith("lda") && fourth.startsWith("sta")) {
+            val firstvalue = first.substring(4)
+            val secondvalue = third.substring(4)
+            if(firstvalue==secondvalue) {
+                // lda value / sta ? / lda same-value / sta ?  -> remove second lda (third line)
+                val address = getAddressArg(first, symbolTable)
+                if(address==null || !machine.isIOAddress(address))
+                    mods.add(Modification(lines[2].index, true, null))
+            }
+        }
+
+        if(first.startsWith("lda") && second.startsWith("ldy") && third.startsWith("sta") && fourth.startsWith("sty") &&
+                fifth.startsWith("lda") && sixth.startsWith("ldy") &&
+                (seventh.startsWith("jsr  floats.copy_float") || seventh.startsWith("jsr  cx16flt.copy_float"))) {
+
+            val nineth = lines[8].value.trimStart()
+            val tenth = lines[9].value.trimStart()
+            val eleventh = lines[10].value.trimStart()
+            val twelveth = lines[11].value.trimStart()
+            val thirteenth = lines[12].value.trimStart()
+            val fourteenth = lines[13].value.trimStart()
+
+            if(eighth.startsWith("lda") && nineth.startsWith("ldy") && tenth.startsWith("sta") && eleventh.startsWith("sty") &&
+                    twelveth.startsWith("lda") && thirteenth.startsWith("ldy") &&
+                    (fourteenth.startsWith("jsr  floats.copy_float") || fourteenth.startsWith("jsr  cx16flt.copy_float"))) {
+
+                if(first.substring(4) == eighth.substring(4) && second.substring(4)==nineth.substring(4)) {
+                    // identical float init
+                    mods.add(Modification(lines[7].index, true, null))
+                    mods.add(Modification(lines[8].index, true, null))
+                    mods.add(Modification(lines[9].index, true, null))
+                    mods.add(Modification(lines[10].index, true, null))
+                }
+            }
+        }
+
+        var overlappingMods = false
+        /*
+        sta  prog8_lib.retval_intermX      ; remove
+        sty  prog8_lib.retval_intermY      ; remove
+        lda  prog8_lib.retval_intermX      ; remove
+        ldy  prog8_lib.retval_intermY      ; remove
+        sta  A1
+        sty  A2
+         */
+        if(first.isStoreReg() && second.isStoreReg()
+            && third.isLoadReg() && fourth.isLoadReg()
+            && fifth.isStoreReg() && sixth.isStoreReg()) {
+            val reg1 = first[2]
+            val reg2 = second[2]
+            val reg3 = third[2]
+            val reg4 = fourth[2]
+            val reg5 = fifth[2]
+            val reg6 = sixth[2]
+            if (reg1 == reg3 && reg1 == reg5 && reg2 == reg4 && reg2 == reg6) {
+                val firstvalue = first.substring(4)
+                val secondvalue = second.substring(4)
+                val thirdvalue = third.substring(4)
+                val fourthvalue = fourth.substring(4)
+                if(firstvalue.contains("prog8_lib.retval_interm") && secondvalue.contains("prog8_lib.retval_interm")
+                    && firstvalue==thirdvalue && secondvalue==fourthvalue) {
+                    mods.add(Modification(lines[0].index, true, null))
+                    mods.add(Modification(lines[1].index, true, null))
+                    mods.add(Modification(lines[2].index, true, null))
+                    mods.add(Modification(lines[3].index, true, null))
+                    overlappingMods = true
+                }
+            }
+        }
+
+        /*
+        sta  A1
+        sty  A2
+        lda  A1     ; can be removed
+        ldy  A2     ; can be removed if not followed by a branch instuction
+         */
+        if(!overlappingMods && first.isStoreReg() && second.isStoreReg()
+            && third.isLoadReg() && fourth.isLoadReg()) {
+            val reg1 = first[2]
+            val reg2 = second[2]
+            val reg3 = third[2]
+            val reg4 = fourth[2]
+            if(reg1==reg3 && reg2==reg4) {
+                val firstvalue = first.substring(4)
+                val secondvalue = second.substring(4)
+                val thirdvalue = third.substring(4)
+                val fourthvalue = fourth.substring(4)
+                if(firstvalue==thirdvalue && secondvalue == fourthvalue) {
+                    val address = getAddressArg(first, symbolTable)
+                    if(address==null || !machine.isIOAddress(address)) {
+                        overlappingMods = true
+                        mods.add(Modification(lines[2].index, true, null))
+                        if (!fifth.startsWith('b'))
+                            mods.add(Modification(lines[3].index, true, null))
+                    }
+                }
+            }
+        }
+
+        /*
+        sta  A1
+        sty  A2     ; ... or stz
+        lda  A1     ; can be removed if not followed by a branch instruction
+         */
+        if(!overlappingMods && first.isStoreReg() && second.isStoreRegOrZero()
+            && third.isLoadReg() && !fourth.isBranch()) {
+            val reg1 = first[2]
+            val reg3 = third[2]
+            if(reg1==reg3) {
+                val firstvalue = first.substring(4)
+                val thirdvalue = third.substring(4)
+                if(firstvalue==thirdvalue) {
+                    val address = getAddressArg(first, symbolTable)
+                    if(address==null || !machine.isIOAddress(address)) {
+                        overlappingMods = true
+                        mods.add(Modification(lines[2].index, true, null))
+                    }
+                }
+            }
+        }
+
+        /*
+        sta  A1
+        ldy  A1     ; make tay
+        sta  A1     ; remove
+         */
+        if(!overlappingMods && first.startsWith("sta") && second.isLoadReg()
+            && third.startsWith("sta") && second.length>4) {
+            val firstvalue = first.substring(4)
+            val secondvalue = second.substring(4)
+            val thirdvalue = third.substring(4)
+            if(firstvalue==secondvalue && firstvalue==thirdvalue) {
+                val address = getAddressArg(first, symbolTable)
+                if(address==null || !machine.isIOAddress(address)) {
+                    overlappingMods = true
+                    val reg2 = second[2]
+                    mods.add(Modification(lines[1].index, false, "  ta$reg2"))
+                    mods.add(Modification(lines[2].index, true, null))
+                }
+            }
+        }
+
+        /*
+        sta  A   ; or stz     double store, remove this first one
+        sta  A   ; or stz
+        However, this cannot be done relyably because 'A' could be a constant symbol referring to an I/O address.
+        We can't see that here and would otherwise delete valid double stores.
+        */
+    }
+
+    return mods
+}
+
+private fun optimizeSamePointerIndexingAndUselessBeq(linesByFourteen: Sequence<List<IndexedValue<String>>>): List<Modification> {
+
+    // Optimize same pointer indexing where for instance we load and store to the same ptr index in Y
+    // if Y isn't modified in between we can omit the second LDY:
+    //    ldy  #0
+    //    lda  (ptr),y
+    //    ora  #3       ; <-- instruction(s) that don't modify Y
+    //    ldy  #0       ; <-- can be removed
+    //    sta  (ptr),y
+
+    val mods = mutableListOf<Modification>()
+    for (lines in linesByFourteen) {
+        val first = lines[0].value.trimStart()
+        val second = lines[1].value.trimStart()
+        val third = lines[2].value.trimStart()
+        val fourth = lines[3].value.trimStart()
+        val fifth = lines[4].value.trimStart()
+        val sixth = lines[5].value.trimStart()
+
+        if(first.startsWith("ldy") && second.startsWith("lda") && fourth.startsWith("ldy") && fifth.startsWith("sta")) {
+            val firstvalue = first.substring(4)
+            val secondvalue = second.substring(4)
+            val fourthvalue = fourth.substring(4)
+            val fifthvalue = fifth.substring(4)
+            if("y" !in third && firstvalue==fourthvalue && secondvalue==fifthvalue && secondvalue.endsWith(",y") && fifthvalue.endsWith(",y")) {
+                mods.add(Modification(lines[3].index, true, null))
+            }
+        }
+        if(first.startsWith("ldy") && second.startsWith("lda") && fifth.startsWith("ldy") && sixth.startsWith("sta")) {
+            val firstvalue = first.substring(4)
+            val secondvalue = second.substring(4)
+            val fifthvalue = fifth.substring(4)
+            val sixthvalue = sixth.substring(4)
+            if("y" !in third && "y" !in fourth && firstvalue==fifthvalue && secondvalue==sixthvalue && secondvalue.endsWith(",y") && sixthvalue.endsWith(",y")) {
+                mods.add(Modification(lines[4].index, true, null))
+            }
+        }
+
+
+        /*
+    beq  +
+    lda  #1
++
+[ optional:  label_xxxx_shortcut   line here]
+    beq  label_xxxx_shortcut   /  bne label_xxxx_shortcut
+or *_afterif labels.
+
+This gets generated after certain if conditions, and only the branch instruction is needed in these cases.
+         */
+
+        if(first=="beq  +" && second=="lda  #1" && third=="+") {
+            if((fourth.startsWith("beq  label_") || fourth.startsWith("bne  label_")) &&
+                (fourth.endsWith("_shortcut") || fourth.endsWith("_afterif") || fourth.endsWith("_shortcut:") || fourth.endsWith("_afterif:"))) {
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, true, null))
+                mods.add(Modification(lines[2].index, true, null))
+            }
+            else if(fourth.startsWith("label_") && (fourth.endsWith("_shortcut") || fourth.endsWith("_shortcut:"))) {
+                if((fifth.startsWith("beq  label_") || fifth.startsWith("bne  label_")) &&
+                    (fifth.endsWith("_shortcut") || fifth.endsWith("_afterif") || fifth.endsWith("_shortcut:") || fifth.endsWith("_afterif:"))) {
+                    mods.add(Modification(lines[0].index, true, null))
+                    mods.add(Modification(lines[1].index, true, null))
+                    mods.add(Modification(lines[2].index, true, null))
+                }
+            }
+        }
+    }
+
+    return mods
+}
+
+private fun optimizeStoreLoadSame(
+    linesByFour: Sequence<List<IndexedValue<String>>>,
+    machine: IMachineDefinition,
+    symbolTable: SymbolTable
+): List<Modification> {
+    val mods = mutableListOf<Modification>()
+    for (lines in linesByFour) {
+        val first = lines[1].value.trimStart()
+        val second = lines[2].value.trimStart()
+        val third = lines[3].value.trimStart()
+
+        // sta X + lda X,  sty X + ldy X,   stx X + ldx X  -> the second instruction can OFTEN be eliminated
+        if ((first.startsWith("sta ") && second.startsWith("lda ")) ||
+                (first.startsWith("stx ") && second.startsWith("ldx ")) ||
+                (first.startsWith("sty ") && second.startsWith("ldy ")) ||
+                (first.startsWith("lda ") && second.startsWith("lda ")) ||
+                (first.startsWith("ldy ") && second.startsWith("ldy ")) ||
+                (first.startsWith("ldx ") && second.startsWith("ldx "))
+        ) {
+            val attemptRemove =
+                if(third.isBranch()) {
+                    // a branch instruction follows, we can only remove the load instruction if
+                    // another load instruction of the same register precedes the store instruction
+                    // (otherwise wrong cpu flags are used)
+                    val loadinstruction = second.substring(0, 3)
+                    lines[0].value.trimStart().startsWith(loadinstruction)
+                }
+                else {
+                    // no branch instruction follows, we can remove the load instruction
+                    val address = getAddressArg(lines[2].value, symbolTable)
+                    address==null || !machine.isIOAddress(address)
+                }
+
+            if(attemptRemove) {
+                val firstLoc = first.substring(4).trimStart()
+                val secondLoc = second.substring(4).trimStart()
+                if (firstLoc == secondLoc)
+                    mods.add(Modification(lines[2].index, true, null))
+            }
+        }
+        else if(first=="pha" && second=="pla" ||
+            first=="phx" && second=="plx" ||
+            first=="phy" && second=="ply" ||
+            first=="php" && second=="plp") {
+            mods.add(Modification(lines[1].index, true, null))
+            mods.add(Modification(lines[2].index, true, null))
+        } else if(first=="pha" && second=="plx") {
+            mods.add(Modification(lines[1].index, true, null))
+            mods.add(Modification(lines[2].index, false, "  tax"))
+        } else if(first=="pha" && second=="ply") {
+            mods.add(Modification(lines[1].index, true, null))
+            mods.add(Modification(lines[2].index, false, "  tay"))
+        } else if(first=="phx" && second=="pla") {
+            mods.add(Modification(lines[1].index, true, null))
+            mods.add(Modification(lines[2].index, false, "  txa"))
+        } else if(first=="phy" && second=="pla") {
+            mods.add(Modification(lines[1].index, true, null))
+            mods.add(Modification(lines[2].index, false, "  tya"))
+        }
+
+
+        // lda X + sta X,  ldy X + sty X,   ldx X + stx X  -> the second instruction can be eliminated
+        if ((first.startsWith("lda ") && second.startsWith("sta ")) ||
+            (first.startsWith("ldx ") && second.startsWith("stx ")) ||
+            (first.startsWith("ldy ") && second.startsWith("sty "))
+        ) {
+            val firstLoc = first.substring(4).trimStart()
+            val secondLoc = second.substring(4).trimStart()
+            if (firstLoc == secondLoc)
+                mods.add(Modification(lines[2].index, true, null))
+        }
+    }
+    return mods
+}
+
+private val identifierRegex = Regex("""^([a-zA-Z_$][a-zA-Z\d_\.$]*)""")
+
+private fun getAddressArg(line: String, symbolTable: SymbolTable): UInt? {
+    // try to get the constant value address, could return null if it's a symbol instead
+    val loadArg = line.trimStart().substring(3).trim()
+    return when {
+        loadArg.startsWith('$') -> loadArg.substring(1).toUIntOrNull(16)
+        loadArg.startsWith('%') -> loadArg.substring(1).toUIntOrNull(2)
+        loadArg.startsWith('#') -> null
+        loadArg.startsWith('(') -> null
+        loadArg[0].isLetter() -> {
+            val identMatch = identifierRegex.find(loadArg)
+            if(identMatch!=null) {
+                val identifier = identMatch.value
+                when (val symbol = symbolTable.flat[identifier]) {
+                    is StConstant -> symbol.value.toUInt()
+                    is StMemVar -> symbol.address
+                    else -> null
+                }
+            } else null
+        }
+        else -> loadArg.substring(1).toUIntOrNull()
+    }
+}
+
+private fun optimizeIncDec(linesByFour: Sequence<List<IndexedValue<String>>>): List<Modification> {
+    // sometimes, iny+dey / inx+dex / dey+iny / dex+inx sequences are generated, these can be eliminated.
+    val mods = mutableListOf<Modification>()
+    for (lines in linesByFour) {
+        val first = lines[0].value
+        val second = lines[1].value
+        if ((" iny" in first || "\tiny" in first) && (" dey" in second || "\tdey" in second)
+                || (" inx" in first || "\tinx" in first) && (" dex" in second || "\tdex" in second)
+                || (" ina" in first || "\tina" in first) && (" dea" in second || "\tdea" in second)
+                || (" inc  a" in first || "\tinc  a" in first) && (" dec  a" in second || "\tdec  a" in second)
+                || (" dey" in first || "\tdey" in first) && (" iny" in second || "\tiny" in second)
+                || (" dex" in first || "\tdex" in first) && (" inx" in second || "\tinx" in second)
+                || (" dea" in first || "\tdea" in first) && (" ina" in second || "\tina" in second)
+                || (" dec  a" in first || "\tdec  a" in first) && (" inc  a" in second || "\tinc  a" in second)) {
+            mods.add(Modification(lines[0].index, true, null))
+            mods.add(Modification(lines[1].index, true, null))
+        }
+
+    }
+    return mods
+}
+
+private fun optimizeJsrRtsAndOtherCombinations(linesByFour: Sequence<List<IndexedValue<String>>>): List<Modification> {
+    // jsr Sub + rts -> jmp Sub
+    // rts + jmp -> remove jmp
+    // rts + bxx -> remove bxx
+    // lda  + cmp #0 -> remove cmp,  same for cpy and cpx.
+    // and some other optimizations.
+
+    val mods = mutableListOf<Modification>()
+    for (lines in linesByFour) {
+        val first = lines[0].value
+        val second = lines[1].value
+        val third = lines[2].value
+        if ((" jsr" in first || "\tjsr" in first ) && (" rts" in second || "\trts" in second)) {
+            mods += Modification(lines[0].index, false, lines[0].value.replace("jsr", "jmp"))
+            mods += Modification(lines[1].index, true, null)
+        }
+        else if (" rts" in first || "\trts" in first) {
+            if (" jmp" in second || "\tjmp" in second)
+                mods += Modification(lines[1].index, true, null)
+            else if (" bra" in second || "\tbra" in second)
+                mods += Modification(lines[1].index, true, null)
+            else if (" bcc" in second || "\tbcc" in second)
+                mods += Modification(lines[1].index, true, null)
+            else if (" bcs" in second || "\tbcs" in second)
+                mods += Modification(lines[1].index, true, null)
+            else if (" beq" in second || "\tbeq" in second)
+                mods += Modification(lines[1].index, true, null)
+            else if (" bne" in second || "\tbne" in second)
+                mods += Modification(lines[1].index, true, null)
+            else if (" bmi" in second || "\tbmi" in second)
+                mods += Modification(lines[1].index, true, null)
+            else if (" bpl" in second || "\tbpl" in second)
+                mods += Modification(lines[1].index, true, null)
+            else if (" bvs" in second || "\tbvs" in second)
+                mods += Modification(lines[1].index, true, null)
+            else if (" bvc" in second || "\tbvc" in second)
+                mods += Modification(lines[1].index, true, null)
+        }
+
+        if (!haslabel(second)) {
+            if ((" lda" in first || "\tlda" in first) && (" cmp  #0" in second || "\tcmp  #0" in second) ||
+                (" ldx" in first || "\tldx" in first) && (" cpx  #0" in second || "\tcpx  #0" in second) ||
+                (" ldy" in first || "\tldy" in first) && (" cpy  #0" in second || "\tcpy  #0" in second)
+            ) {
+                mods.add(Modification(lines[1].index, true, null))
+            }
+            else if(" cmp  #0" in second || "\tcmp  #0" in second) {
+                // there are many instructions that modify A and set the bits...
+                for(instr in arrayOf("lda", "ora", "and", "eor", "adc", "sbc", "asl", "cmp", "inc  a", "lsr", "pla", "rol", "ror", "txa", "tya")) {
+                    if(" $instr" in first || "\t$instr" in first) {
+                        mods.add(Modification(lines[1].index, true, null))
+                    }
+                }
+            }
+        }
+
+        /*
+    LDA NUM1
+    CMP NUM2
+    BCC LABEL
+    BEQ LABEL
+
+(or something similar) which branches to LABEL when NUM1 <= NUM2. (In this case NUM1 and NUM2 are unsigned numbers.) However, consider the following sequence:
+
+    LDA NUM2
+    CMP NUM1
+    BCS LABEL
+         */
+        val tfirst = first.trimStart()
+        val tsecond = second.trimStart()
+        val tthird = lines[2].value.trimStart()
+        val tfourth = lines[3].value.trimStart()
+        if(tfirst.startsWith("lda") && tsecond.startsWith("cmp") && tthird.startsWith("bcc") && tfourth.startsWith("beq")) {
+            val label = tthird.substring(4)
+            if(label==tfourth.substring(4)) {
+                mods += Modification(lines[0].index, false, "  lda  ${tsecond.substring(4)}")
+                mods += Modification(lines[1].index, false, "  cmp  ${tfirst.substring(4)}")
+                mods += Modification(lines[2].index, false, "  bcs  $label")
+                mods += Modification(lines[3].index, true, null)
+            }
+        }
+
+
+        fun sameLabel(branchInstr: String, jumpInstr: String, labelInstr: String): Boolean {
+            if('(' in jumpInstr) return false       // indirect jump cannot be replaced
+            val label = labelInstr.trimEnd().substringBefore(':').substringBefore(' ').substringBefore('\t')
+            val branchLabel = branchInstr.trimStart().substring(3).trim()
+            return label==branchLabel
+        }
+
+        // beq Label + jmp Addr + Label  -> bne Addr
+        if((" jmp" in second || "\tjmp " in second) && haslabel(third)) {
+            if((" beq " in first || "\tbeq " in first) && sameLabel(first, second, third)) {
+                val branch = second.replace("jmp", "bne")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+            else if((" bne " in first || "\tbne " in first) && sameLabel(first, second, third)) {
+                val branch = second.replace("jmp", "beq")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+            else if((" bcc " in first || "\tbcc " in first) && sameLabel(first, second, third)){
+                val branch = second.replace("jmp", "bcs")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+            else if((" bcs " in first || "\tbcs " in first) && sameLabel(first, second, third)) {
+                val branch = second.replace("jmp", "bcc")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+            else if((" bpl " in first || "\tbpl " in first) && sameLabel(first, second, third)) {
+                val branch = second.replace("jmp", "bmi")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+            else if((" bmi " in first || "\tbmi " in first) && sameLabel(first, second, third)) {
+                val branch = second.replace("jmp", "bpl")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+            else if((" bvc " in first || "\tbvc " in first) && sameLabel(first, second, third)) {
+                val branch = second.replace("jmp", "bvs")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+            else if((" bvs " in first || "\tbvs " in first) && sameLabel(first, second, third)) {
+                val branch = second.replace("jmp", "bvc")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+        }
+    }
+    return mods
+}
+
+private fun optimizeUselessPushPopStack(linesByFour: Sequence<List<IndexedValue<String>>>): List<Modification> {
+    val mods = mutableListOf<Modification>()
+
+    fun optimize(register: Char, lines: List<IndexedValue<String>>) {
+        if(lines[0].value.trimStart().startsWith("ph$register")) {
+            if(lines[2].value.trimStart().startsWith("pl$register")) {
+                val second = lines[1].value.trimStart().take(6).lowercase()
+                if(register!in second
+                    && !second.startsWith("jsr")
+                    && !second.startsWith("pl")
+                    && !second.startsWith("ph")) {
+                    mods.add(Modification(lines[0].index, true, null))
+                    mods.add(Modification(lines[2].index, true, null))
+                }
+            }
+            else if (lines[3].value.trimStart().startsWith("pl$register")) {
+                val second = lines[1].value.trimStart().take(6).lowercase()
+                val third = lines[2].value.trimStart().take(6).lowercase()
+                if(register !in second && register !in third
+                    && !second.startsWith("jsr") && !third.startsWith("jsr")
+                    && !second.startsWith("pl") && !third.startsWith("pl")
+                    && !second.startsWith("ph") && !third.startsWith("ph")) {
+                    mods.add(Modification(lines[0].index, true, null))
+                    mods.add(Modification(lines[3].index, true, null))
+                }
+            }
+        }
+    }
+
+    for (lines in linesByFour) {
+        optimize('a', lines)
+        optimize('x', lines)
+        optimize('y', lines)
+
+        val first = lines[1].value.trimStart()
+        val second = lines[2].value.trimStart()
+        val third = lines[3].value.trimStart()
+
+        // phy + ldy + pla -> tya + ldy
+        // phx + ldx + pla -> txa + ldx
+        // pha + lda + pla -> nop
+        if(first=="phy" && second.startsWith("ldy ") && third=="pla") {
+            mods.add(Modification(lines[3].index, true, null))
+            mods.add(Modification(lines[1].index, false, "  tya"))
+        }
+        else if(first=="phx" && second.startsWith("ldx ") && third=="pla") {
+            mods.add(Modification(lines[3].index, true, null))
+            mods.add(Modification(lines[1].index, false, "  txa"))
+        }
+        else if(first=="pha" && second.startsWith("lda ") && third=="pla") {
+            mods.add(Modification(lines[1].index, true, null))
+            mods.add(Modification(lines[2].index, true, null))
+            mods.add(Modification(lines[3].index, true, null))
+        }
+    }
+
+
+    return mods
+}
+
+
+private fun optimizeTSBtoRegularOr(linesByFour: Sequence<List<IndexedValue<String>>>): List<Modification> {
+    // Asm peephole:   lda var2 / tsb var1 / lda var1  Replace this with this to save 1 cycle:   lda var1 / ora var2 / sta var1
+    val mods = mutableListOf<Modification>()
+
+    for(lines in linesByFour) {
+        val first = lines[0].value.trimStart()
+        val second = lines[1].value.trimStart()
+        val third = lines[2].value.trimStart()
+        if(first.startsWith("lda") && second.startsWith("tsb") && third.startsWith("lda")) {
+            val operand1 = first.substring(3)
+            val operand2 = second.substring(3)
+            val operand3 = third.substring(3)
+            if(operand1!=operand2 && operand2==operand3) {
+                mods.add(Modification(lines[0].index, false, "  lda  $operand2"))
+                mods.add(Modification(lines[1].index, false, "  ora  $operand1"))
+                mods.add(Modification(lines[2].index, false, "  sta  $operand2"))
+            }
+        }
+    }
+    return mods
+}
+
+private fun optimizeUnneededTempvarInAdd(linesByFour: Sequence<List<IndexedValue<String>>>): List<Modification> {
+    // sequence:  sta  P8ZP_SCRATCH_XX  / lda  something / clc / adc  P8ZP_SCRATCH_XX
+    // this can be performed without the scratch variable:  clc  /  adc  something
+    val mods = mutableListOf<Modification>()
+
+    for(lines in linesByFour) {
+        val first = lines[0].value.trimStart()
+        val second = lines[1].value.trimStart()
+        val third = lines[2].value.trimStart()
+        val fourth = lines[3].value.trimStart()
+        if(first.startsWith("sta  P8ZP_SCRATCH_") && second.startsWith("lda") && third.startsWith("clc") && fourth.startsWith("adc  P8ZP_SCRATCH_") ) {
+            if(fourth.substring(4)==first.substring(4)) {
+                mods.add(Modification(lines[0].index, false, "  clc"))
+                mods.add(Modification(lines[1].index, false, "  adc  ${second.substring(3).trimStart()}"))
+                mods.add(Modification(lines[2].index, true, null))
+                mods.add(Modification(lines[3].index, true, null))
+            }
+        }
+    }
+
+    return mods
+}

codeGenCpu6502/src/prog8/codegen/cpu6502/AsmsubHelpers.kt

@@ -0,0 +1,28 @@
+package prog8.codegen.cpu6502
+
+import prog8.code.ast.PtAsmSub
+import prog8.code.core.Cx16VirtualRegisters
+import prog8.code.core.RegisterOrPair
+
+
+fun asmsub6502ArgsEvalOrder(sub: PtAsmSub): List<Int> {
+    val order = mutableListOf<Int>()
+    // order is:
+    //  1) cx16 virtual word registers,
+    //  2) paired CPU registers,
+    //  3) single CPU registers (order Y,X,A),
+    //  4) CPU Carry status flag
+    val args = sub.parameters.withIndex()
+    val (cx16regs, args2) = args.partition { it.value.first.registerOrPair in Cx16VirtualRegisters }
+    val pairedRegisters = arrayOf(RegisterOrPair.AX, RegisterOrPair.AY, RegisterOrPair.XY)
+    val (pairedRegs , args3) = args2.partition { it.value.first.registerOrPair in pairedRegisters }
+    val (singleRegs, rest) = args3.partition { it.value.first.registerOrPair != null }
+
+    cx16regs.forEach { order += it.index }
+    pairedRegs.forEach { order += it.index }
+    singleRegs.sortedBy { it.value.first.registerOrPair!!.asCpuRegister() }.asReversed().forEach { order += it.index }
+    require(rest.all { it.value.first.registerOrPair==null && it.value.first.statusflag!=null})
+    rest.forEach { order += it.index }
+    require(order.size==sub.parameters.size)
+    return order
+}

codeGenCpu6502/src/prog8/codegen/cpu6502/AssemblyProgram.kt

@@ -0,0 +1,137 @@
+package prog8.codegen.cpu6502
+
+import prog8.code.core.*
+import prog8.code.target.C64Target
+import java.nio.file.Path
+
+
+internal class AssemblyProgram(
+        override val name: String,
+        outputDir: Path,
+        private val compTarget: ICompilationTarget) : IAssemblyProgram {
+
+    private val assemblyFile = outputDir.resolve("$name.asm")
+    private val prgFile = outputDir.resolve("$name.prg")        // CBM prg executable program
+    private val xexFile = outputDir.resolve("$name.xex")        // Atari xex executable program
+    private val binFile = outputDir.resolve("$name.bin")
+    private val viceMonListFile = outputDir.resolve(C64Target.viceMonListName(name))
+    private val listFile = outputDir.resolve("$name.list")
+
+    override fun assemble(options: CompilationOptions, errors: IErrorReporter): Boolean {
+
+        val assemblerCommand: List<String>
+
+        when (compTarget.name) {
+            in setOf("c64", "c128", "cx16", "pet32") -> {
+                // CBM machines .prg generation.
+
+                // add "-Wlong-branch"  to see warnings about conversion of branch instructions to jumps (default = do this silently)
+                val command = mutableListOf("64tass", "--ascii", "--case-sensitive", "--long-branch",
+                    "-Wall", // "-Wno-strict-bool", "-Werror",
+                    "--dump-labels", "--vice-labels", "--labels=$viceMonListFile"
+                )
+
+                if(options.warnSymbolShadowing)
+                    command.add("-Wshadow")
+                else
+                    command.add("-Wno-shadow")
+
+                if(options.asmQuiet)
+                    command.add("--quiet")
+
+                if(options.asmListfile) {
+                    command.addAll(listOf("--list=$listFile", "--no-monitor"))
+                }
+
+                val outFile = when (options.output) {
+                    OutputType.PRG -> {
+                        command.add("--cbm-prg")
+                        println("\nCreating prg for target ${compTarget.name}.")
+                        prgFile
+                    }
+                    OutputType.RAW -> {
+                        command.add("--nostart")
+                        println("\nCreating raw binary for target ${compTarget.name}.")
+                        binFile
+                    }
+                    else -> throw AssemblyError("invalid output type")
+                }
+                command.addAll(listOf("--output", outFile.toString(), assemblyFile.toString()))
+                assemblerCommand = command
+
+            }
+            "atari" -> {
+                // Atari800XL .xex generation.
+
+                // TODO are these options okay for atari?
+                val command = mutableListOf("64tass", "--ascii", "--case-sensitive", "--long-branch",
+                    "-Wall", // "-Werror", "-Wno-strict-bool"
+                    "--no-monitor"
+                )
+
+                if(options.warnSymbolShadowing)
+                    command.add("-Wshadow")
+                else
+                    command.add("-Wno-shadow")
+
+                if(options.asmQuiet)
+                    command.add("--quiet")
+
+                if(options.asmListfile)
+                    command.add("--list=$listFile")
+
+                val outFile = when (options.output) {
+                    OutputType.XEX -> {
+                        command.add("--atari-xex")
+                        println("\nCreating xex for target ${compTarget.name}.")
+                        xexFile
+                    }
+                    OutputType.RAW -> {
+                        command.add("--nostart")
+                        println("\nCreating raw binary for target ${compTarget.name}.")
+                        binFile
+                    }
+                    else -> throw AssemblyError("invalid output type")
+                }
+                command.addAll(listOf("--output", outFile.toString(), assemblyFile.toString()))
+                assemblerCommand = command
+            }
+            else -> throw AssemblyError("invalid compilation target")
+        }
+
+        val proc = ProcessBuilder(assemblerCommand).inheritIO().start()
+        val result = proc.waitFor()
+        if (result == 0 && compTarget.name!="atari") {
+            removeGeneratedLabelsFromMonlist()
+            generateBreakpointList()
+        }
+        return result==0
+    }
+
+    private fun removeGeneratedLabelsFromMonlist() {
+        val pattern = Regex("""al (\w+) \S+prog8_label_.+?""")
+        val lines = viceMonListFile.toFile().readLines()
+        viceMonListFile.toFile().outputStream().bufferedWriter().use {
+            for (line in lines) {
+                if(pattern.matchEntire(line)==null)
+                    it.write(line+"\n")
+            }
+        }
+    }
+
+    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 viceMonListFile.toFile().readLines()) {
+            val match = pattern.matchEntire(line)
+            if (match != null)
+                breakpoints.add("break \$" + match.groupValues[1])
+        }
+        val num = breakpoints.size
+        breakpoints.add(0, "; breakpoint list now follows")
+        breakpoints.add(1, "; $num breakpoints have been defined")
+        breakpoints.add(2, "del")
+        viceMonListFile.toFile().appendText(breakpoints.joinToString("\n") + "\n")
+    }
+}

codeGenCpu6502/src/prog8/codegen/cpu6502/Extensions.kt

@@ -0,0 +1,40 @@
+package prog8.codegen.cpu6502
+
+import prog8.code.ast.IPtSubroutine
+import prog8.code.ast.PtAsmSub
+import prog8.code.ast.PtSub
+import prog8.code.core.*
+
+
+internal fun IPtSubroutine.returnsWhatWhere(): List<Pair<RegisterOrStatusflag, DataType>> {
+    when(this) {
+        is PtAsmSub -> {
+            return returns
+        }
+        is PtSub -> {
+            // for non-asm subroutines, determine the return registers based on the type of the return value
+            return if(returntype==null)
+                emptyList()
+            else {
+                val register = when (returntype!!) {
+                    in ByteDatatypesWithBoolean -> RegisterOrStatusflag(RegisterOrPair.A, null)
+                    in WordDatatypes -> RegisterOrStatusflag(RegisterOrPair.AY, null)
+                    DataType.FLOAT -> RegisterOrStatusflag(RegisterOrPair.FAC1, null)
+                    else -> RegisterOrStatusflag(RegisterOrPair.AY, null)
+                }
+                listOf(Pair(register, returntype!!))
+            }
+        }
+    }
+}
+
+
+internal fun PtSub.returnRegister(): RegisterOrStatusflag? {
+    return when(returntype) {
+        in ByteDatatypesWithBoolean -> RegisterOrStatusflag(RegisterOrPair.A, null)
+        in WordDatatypes -> RegisterOrStatusflag(RegisterOrPair.AY, null)
+        DataType.FLOAT -> RegisterOrStatusflag(RegisterOrPair.FAC1, null)
+        null -> null
+        else -> RegisterOrStatusflag(RegisterOrPair.AY, null)
+    }
+}

codeGenCpu6502/src/prog8/codegen/cpu6502/ForLoopsAsmGen.kt

@@ -0,0 +1,730 @@
+package prog8.codegen.cpu6502
+
+import com.github.michaelbull.result.fold
+import prog8.code.StMemVar
+import prog8.code.StStaticVariable
+import prog8.code.ast.PtForLoop
+import prog8.code.ast.PtIdentifier
+import prog8.code.ast.PtRange
+import prog8.code.core.*
+import kotlin.math.absoluteValue
+
+internal class ForLoopsAsmGen(
+    private val asmgen: AsmGen6502Internal,
+    private val zeropage: Zeropage
+) {
+
+    internal fun translate(stmt: PtForLoop) {
+        val iterableDt = stmt.iterable.type
+        when(stmt.iterable) {
+            is PtRange -> {
+                val range = (stmt.iterable as PtRange).toConstantIntegerRange()
+                if(range==null) {
+                    translateForOverNonconstRange(stmt, iterableDt, stmt.iterable as PtRange)
+                } else {
+                    translateForOverConstRange(stmt, iterableDt, range)
+                }
+            }
+            is PtIdentifier -> {
+                translateForOverIterableVar(stmt, iterableDt, stmt.iterable as PtIdentifier)
+            }
+            else -> throw AssemblyError("can't iterate over ${stmt.iterable.javaClass} - should have been replaced by a variable")
+        }
+    }
+
+    private fun translateForOverNonconstRange(stmt: PtForLoop, iterableDt: DataType, range: PtRange) {
+        val loopLabel = asmgen.makeLabel("for_loop")
+        val endLabel = asmgen.makeLabel("for_end")
+        val modifiedLabel = asmgen.makeLabel("for_modified")
+        val modifiedLabel2 = asmgen.makeLabel("for_modifiedb")
+        asmgen.loopEndLabels.push(endLabel)
+        val stepsize=range.step.asConstInteger()!!
+
+        if(stepsize < -1) {
+            val limit = range.to.asConstInteger()
+            if(limit==0)
+                throw AssemblyError("for unsigned loop variable it's not possible to count down with step != -1 from a non-const value to exactly zero due to value wrapping")
+        }
+
+        when(iterableDt) {
+            DataType.ARRAY_B, DataType.ARRAY_UB -> {
+                if (stepsize==1 || stepsize==-1) {
+
+                    // bytes array, step 1 or -1
+
+                    val incdec = if(stepsize==1) "inc" else "dec"
+                    // loop over byte range via loopvar
+                    val varname = asmgen.asmVariableName(stmt.variable)
+                    asmgen.assignExpressionToVariable(range.from, varname, ArrayToElementTypes.getValue(iterableDt))
+                    asmgen.assignExpressionToRegister(range.to, RegisterOrPair.A, false)
+                    // pre-check for end already reached
+                    if(iterableDt==DataType.ARRAY_B) {
+                        asmgen.out("  sta  $modifiedLabel+1")
+                        if(stepsize<0)
+                            asmgen.out("""
+                                clc
+                                sbc  $varname
+                                bvc  +
+                                eor  #${'$'}80
++                               bpl  $endLabel""")
+                        else
+                            asmgen.out("""
+                                sec
+                                sbc  $varname
+                                bvc  +
+                                eor  #${'$'}80
++                               bmi  $endLabel""")
+                    } else {
+                        if(stepsize<0)
+                            asmgen.out("""
+                                cmp  $varname
+                                beq  +
+                                bcs  $endLabel
++""")
+                        else
+                            asmgen.out("  cmp  $varname  |  bcc  $endLabel")
+                        asmgen.out("  sta  $modifiedLabel+1")
+                    }
+                    asmgen.out(loopLabel)
+                    asmgen.translate(stmt.statements)
+                    asmgen.out("""
+                        lda  $varname
+$modifiedLabel          cmp  #0         ; modified 
+                        beq  $endLabel
+                        $incdec  $varname""")
+                    asmgen.jmp(loopLabel)
+                    asmgen.out(endLabel)
+
+                } else {
+
+                    // bytes, step >= 2 or <= -2
+
+                    // loop over byte range via loopvar
+                    val varname = asmgen.asmVariableName(stmt.variable)
+                    asmgen.assignExpressionToVariable(range.from, varname, ArrayToElementTypes.getValue(iterableDt))
+                    asmgen.assignExpressionToRegister(range.to, RegisterOrPair.A, false)
+                    // pre-check for end already reached
+                    if(iterableDt==DataType.ARRAY_B) {
+                        asmgen.out("  sta  $modifiedLabel+1")
+                        if(stepsize<0)
+                            asmgen.out("""
+                                clc
+                                sbc  $varname
+                                bvc  +
+                                eor  #${'$'}80
++                               bpl  $endLabel""")
+                        else
+                            asmgen.out("""
+                                sec
+                                sbc  $varname
+                                bvc  +
+                                eor  #${'$'}80
++                               bmi  $endLabel""")
+                    } else {
+                        if(stepsize<0)
+                            asmgen.out("""
+                                cmp  $varname
+                                beq  +
+                                bcs  $endLabel
++""")
+                        else
+                            asmgen.out("  cmp  $varname  |  bcc  $endLabel")
+                        asmgen.out("  sta  $modifiedLabel+1")
+                    }
+                    asmgen.out(loopLabel)
+                    asmgen.translate(stmt.statements)
+                    if(stepsize>0) {
+                        asmgen.out("""
+                            lda  $varname
+                            clc
+                            adc  #$stepsize
+                            sta  $varname
+$modifiedLabel              cmp  #0    ; modified
+                            bmi  $loopLabel
+                            beq  $loopLabel""")
+                    } else {
+                        asmgen.out("""
+                            lda  $varname
+                            sec
+                            sbc  #${stepsize.absoluteValue}
+                            sta  $varname
+$modifiedLabel              cmp  #0     ; modified
+                            bpl  $loopLabel""")
+                    }
+                    asmgen.out(endLabel)
+                }
+            }
+            DataType.ARRAY_W, DataType.ARRAY_UW -> {
+                when {
+
+                    // words, step 1 or -1
+
+                    stepsize == 1 || stepsize == -1 -> {
+                        val varname = asmgen.asmVariableName(stmt.variable)
+                        assignLoopvarWord(stmt, range)
+                        asmgen.assignExpressionToRegister(range.to, RegisterOrPair.AY)
+                        precheckFromToWord(iterableDt, stepsize, varname, endLabel)
+                        asmgen.out("""
+                            sty  $modifiedLabel+1
+                            sta  $modifiedLabel2+1
+$loopLabel""")
+                        asmgen.translate(stmt.statements)
+                        asmgen.out("""
+                lda  $varname+1
+$modifiedLabel  cmp  #0    ; modified 
+                bne  +
+                lda  $varname
+$modifiedLabel2 cmp  #0    ; modified 
+                beq  $endLabel""")
+                        if(stepsize==1) {
+                            asmgen.out("""
++               inc  $varname
+                bne  $loopLabel
+                inc  $varname+1""")
+                            asmgen.jmp(loopLabel)
+                        } else {
+                            asmgen.out("""
++               lda  $varname
+                bne  +
+                dec  $varname+1
++               dec  $varname""")
+                            asmgen.jmp(loopLabel)
+                        }
+                        asmgen.out(endLabel)
+                    }
+                    stepsize > 0 -> {
+
+                        // (u)words, step >= 2
+                        val varname = asmgen.asmVariableName(stmt.variable)
+                        assignLoopvarWord(stmt, range)
+                        asmgen.assignExpressionToRegister(range.to, RegisterOrPair.AY)
+                        precheckFromToWord(iterableDt, stepsize, varname, endLabel)
+                        asmgen.out("""
+                            sty  $modifiedLabel+1
+                            sta  $modifiedLabel2+1
+$loopLabel""")
+                        asmgen.translate(stmt.statements)
+
+                        if (iterableDt == DataType.ARRAY_UW) {
+                            asmgen.out("""
+                lda  $varname
+                clc
+                adc  #<$stepsize
+                sta  $varname
+                lda  $varname+1
+                adc  #>$stepsize
+                sta  $varname+1
+$modifiedLabel  cmp  #0     ; modified
+                bcc  $loopLabel
+                bne  $endLabel
+$modifiedLabel2 lda  #0     ; modified
+                cmp  $varname
+                bcc  $endLabel
+                bcs  $loopLabel
+$endLabel""")
+                        } else {
+                            asmgen.out("""
+                lda  $varname
+                clc
+                adc  #<$stepsize
+                sta  $varname
+                lda  $varname+1
+                adc  #>$stepsize
+                sta  $varname+1
+$modifiedLabel2 lda  #0   ; modified
+                cmp  $varname
+$modifiedLabel  lda  #0   ; modified
+                sbc  $varname+1
+                bvc  +
+                eor  #$80
++               bpl  $loopLabel                
+$endLabel""")
+                        }
+                    }
+                    else -> {
+
+                        // (u)words, step <= -2
+                        val varname = asmgen.asmVariableName(stmt.variable)
+                        assignLoopvarWord(stmt, range)
+                        asmgen.assignExpressionToRegister(range.to, RegisterOrPair.AY)
+                        precheckFromToWord(iterableDt, stepsize, varname, endLabel)
+                        asmgen.out("""
+                            sty  $modifiedLabel+1
+                            sta  $modifiedLabel2+1
+$loopLabel""")
+                        asmgen.translate(stmt.statements)
+
+                            asmgen.out("""
+                lda  $varname
+                sec
+                sbc  #<${stepsize.absoluteValue}
+                sta  $varname
+                tax
+                lda  $varname+1
+                sbc  #>${stepsize.absoluteValue}
+                sta  $varname+1
+                txa
+$modifiedLabel2 cmp  #0    ; modified 
+                lda  $varname+1
+$modifiedLabel  sbc  #0    ; modified
+                bvc  +
+                eor  #$80
++               bpl  $loopLabel                
+$endLabel""")
+                    }
+                }
+            }
+            else -> throw AssemblyError("range expression can only be byte or word")
+        }
+
+        asmgen.loopEndLabels.pop()
+    }
+
+    private fun precheckFromToWord(iterableDt: DataType, stepsize: Int, fromVar: String, endLabel: String) {
+        // pre-check for end already reached.
+        // 'to' is in AY, do NOT clobber this!
+        if(iterableDt==DataType.ARRAY_W) {
+            if(stepsize<0)
+                asmgen.out("""
+                    sta  P8ZP_SCRATCH_W2        ; to
+                    sty  P8ZP_SCRATCH_W2+1      ; to
+                    lda  $fromVar
+	                cmp  P8ZP_SCRATCH_W2
+                    lda  $fromVar+1
+	                sbc  P8ZP_SCRATCH_W2+1
+	                bvc  +
+	                eor  #${'$'}80
++           		bmi  $endLabel
+                    lda  P8ZP_SCRATCH_W2
+                    ldy  P8ZP_SCRATCH_W2+1""")
+            else
+                asmgen.out("""
+                    sta  P8ZP_SCRATCH_REG
+	                cmp  $fromVar
+	                tya
+	                sbc  $fromVar+1
+	                bvc  +
+	                eor  #${'$'}80
++           		bmi  $endLabel
+                    lda  P8ZP_SCRATCH_REG""")
+        } else {
+            if(stepsize<0)
+                asmgen.out("""
+                    cpy  $fromVar+1
+                    beq  +
+                    bcc  ++
+                    bcs  $endLabel
++                   cmp  $fromVar
+                    bcc  +
+                    beq  +
+                    bne  $endLabel
++""")
+            else
+                asmgen.out("""
+                	cpy  $fromVar+1
+	                bcc  $endLabel
+	                bne  +
+	                cmp  $fromVar
+	                bcc  $endLabel
++""")
+        }
+    }
+
+    private fun translateForOverIterableVar(stmt: PtForLoop, iterableDt: DataType, ident: PtIdentifier) {
+        val loopLabel = asmgen.makeLabel("for_loop")
+        val endLabel = asmgen.makeLabel("for_end")
+        asmgen.loopEndLabels.push(endLabel)
+        val iterableName = asmgen.asmVariableName(ident)
+        val numElements = when(val symbol = asmgen.symbolTable.lookup(ident.name)) {
+            is StStaticVariable -> symbol.length!!
+            is StMemVar -> symbol.length!!
+            else -> 0
+        }
+        when(iterableDt) {
+            DataType.STR -> {
+                asmgen.out("""
+                    lda  #<$iterableName
+                    ldy  #>$iterableName
+                    sta  $loopLabel+1
+                    sty  $loopLabel+2
+$loopLabel          lda  ${65535.toHex()}       ; modified
+                    beq  $endLabel
+                    sta  ${asmgen.asmVariableName(stmt.variable)}""")
+                asmgen.translate(stmt.statements)
+                asmgen.out("""
+                    inc  $loopLabel+1
+                    bne  $loopLabel
+                    inc  $loopLabel+2
+                    bne  $loopLabel
+$endLabel""")
+            }
+            DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_BOOL -> {
+                val indexVar = asmgen.makeLabel("for_index")
+                asmgen.out("""
+                    ldy  #0
+$loopLabel          sty  $indexVar
+                    lda  $iterableName,y
+                    sta  ${asmgen.asmVariableName(stmt.variable)}""")
+                asmgen.translate(stmt.statements)
+                if(numElements<=255) {
+                    asmgen.out("""
+                        ldy  $indexVar
+                        iny
+                        cpy  #$numElements
+                        beq  $endLabel
+                        bne  $loopLabel""")
+                } else {
+                    // length is 256
+                    asmgen.out("""
+                        ldy  $indexVar
+                        iny
+                        bne  $loopLabel
+                        beq  $endLabel""")
+                }
+                if(numElements>=16) {
+                    // allocate index var on ZP if possible
+                    val result = zeropage.allocate(indexVar, DataType.UBYTE, null, stmt.position, asmgen.errors)
+                    result.fold(
+                        success = { (address, _, _)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
+                        failure = { asmgen.out("$indexVar    .byte  0") }
+                    )
+                } else {
+                    asmgen.out("$indexVar    .byte  0")
+                }
+                asmgen.out(endLabel)
+            }
+            DataType.ARRAY_W, DataType.ARRAY_UW -> {
+                val length = numElements * 2
+                val indexVar = asmgen.makeLabel("for_index")
+                val loopvarName = asmgen.asmVariableName(stmt.variable)
+                asmgen.out("""
+                    ldy  #0
+$loopLabel          sty  $indexVar
+                    lda  $iterableName,y
+                    sta  $loopvarName
+                    lda  $iterableName+1,y
+                    sta  $loopvarName+1""")
+                asmgen.translate(stmt.statements)
+                if(length<=127) {
+                    asmgen.out("""
+                        ldy  $indexVar
+                        iny
+                        iny
+                        cpy  #$length
+                        beq  $endLabel
+                        bne  $loopLabel""")
+                } else {
+                    // length is 128 words, 256 bytes
+                    asmgen.out("""
+                        ldy  $indexVar
+                        iny
+                        iny
+                        bne  $loopLabel
+                        beq  $endLabel""")
+                }
+                if(length>=16) {
+                    // allocate index var on ZP if possible
+                    val result = zeropage.allocate(indexVar, DataType.UBYTE, null, stmt.position, asmgen.errors)
+                    result.fold(
+                        success = { (address,_,_)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
+                        failure = { asmgen.out("$indexVar    .byte  0") }
+                    )
+                } else {
+                    asmgen.out("$indexVar    .byte  0")
+                }
+                asmgen.out(endLabel)
+            }
+            DataType.ARRAY_UW_SPLIT, DataType.ARRAY_W_SPLIT -> {
+                val indexVar = asmgen.makeLabel("for_index")
+                val loopvarName = asmgen.asmVariableName(stmt.variable)
+                asmgen.out("""
+                    ldy  #0
+$loopLabel          sty  $indexVar
+                    lda  ${iterableName}_lsb,y
+                    sta  $loopvarName
+                    lda  ${iterableName}_msb,y
+                    sta  $loopvarName+1""")
+                asmgen.translate(stmt.statements)
+                if(numElements<=255) {
+                    asmgen.out("""
+                        ldy  $indexVar
+                        iny
+                        cpy  #$numElements
+                        beq  $endLabel
+                        bne  $loopLabel""")
+                } else {
+                    // length is 256
+                    asmgen.out("""
+                        ldy  $indexVar
+                        iny
+                        bne  $loopLabel
+                        beq  $endLabel""")
+                }
+                if(numElements>=16) {
+                    // allocate index var on ZP if possible
+                    val result = zeropage.allocate(indexVar, DataType.UBYTE, null, stmt.position, asmgen.errors)
+                    result.fold(
+                        success = { (address,_,_)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
+                        failure = { asmgen.out("$indexVar    .byte  0") }
+                    )
+                } else {
+                    asmgen.out("$indexVar    .byte  0")
+                }
+                asmgen.out(endLabel)
+            }
+            DataType.ARRAY_F -> {
+                throw AssemblyError("for loop with floating point variables is not supported")
+            }
+            else -> throw AssemblyError("can't iterate over $iterableDt")
+        }
+        asmgen.loopEndLabels.pop()
+    }
+
+    private fun translateForOverConstRange(stmt: PtForLoop, iterableDt: DataType, range: IntProgression) {
+        if (range.isEmpty() || range.step==0)
+            throw AssemblyError("empty range or step 0")
+        if(iterableDt==DataType.ARRAY_B || iterableDt==DataType.ARRAY_UB) {
+            if(range.step==1 && range.last>range.first) return translateForSimpleByteRangeAsc(stmt, range)
+            if(range.step==-1 && range.last<range.first) return translateForSimpleByteRangeDesc(stmt, range)
+        }
+        else if(iterableDt==DataType.ARRAY_W || iterableDt==DataType.ARRAY_UW) {
+            if(range.step==1 && range.last>range.first) return translateForSimpleWordRangeAsc(stmt, range)
+            if(range.step==-1 && range.last<range.first) return translateForSimpleWordRangeDesc(stmt, range)
+        }
+
+        // not one of the easy cases, generate more complex code...
+        val loopLabel = asmgen.makeLabel("for_loop")
+        val endLabel = asmgen.makeLabel("for_end")
+        asmgen.loopEndLabels.push(endLabel)
+        when(iterableDt) {
+            DataType.ARRAY_B, DataType.ARRAY_UB -> {
+                // loop over byte range via loopvar, step >= 2 or <= -2
+                val varname = asmgen.asmVariableName(stmt.variable)
+                asmgen.out("""
+                            lda  #${range.first}
+                            sta  $varname
+$loopLabel""")
+                asmgen.translate(stmt.statements)
+                when (range.step) {
+                    0, 1, -1 -> {
+                        throw AssemblyError("step 0, 1 and -1 should have been handled specifically  $stmt")
+                    }
+                    2 -> {
+                        if(range.last==255 || range.last==254) {
+                            asmgen.out("""
+                                inc  $varname
+                                beq  $endLabel
+                                inc  $varname
+                                bne  $loopLabel""")
+                        } else {
+                            asmgen.out("""
+                                inc  $varname
+                                inc  $varname
+                                lda  $varname
+                                cmp  #${range.last+2}
+                                bne  $loopLabel""")
+                        }
+                    }
+                    -2 -> {
+                        when (range.last) {
+                            0 -> {
+                                asmgen.out("""
+                                    lda  $varname
+                                    beq  $endLabel
+                                    dec  $varname
+                                    dec  $varname""")
+                                asmgen.jmp(loopLabel)
+                            }
+                            1 -> asmgen.out("""
+                                    dec  $varname
+                                    beq  $endLabel
+                                    dec  $varname
+                                    bne  $loopLabel""")
+                            else -> asmgen.out("""
+                                    dec  $varname
+                                    dec  $varname
+                                    lda  $varname
+                                    cmp  #${range.last-2}
+                                    bne  $loopLabel""")
+                        }
+                    }
+                    else -> {
+                        // step <= -3 or >= 3
+                        asmgen.out("""
+                            lda  $varname
+                            cmp  #${range.last}
+                            beq  $endLabel
+                            clc
+                            adc  #${range.step}
+                            sta  $varname""")
+                        asmgen.jmp(loopLabel)
+                    }
+                }
+                asmgen.out(endLabel)
+            }
+            DataType.ARRAY_W, DataType.ARRAY_UW -> {
+                // loop over word range via loopvar, step >= 2 or <= -2
+                val varname = asmgen.asmVariableName(stmt.variable)
+                when (range.step) {
+                    0, 1, -1 -> {
+                        throw AssemblyError("step 0, 1 and -1 should have been handled specifically  $stmt")
+                    }
+                    else -> {
+                        // word, step >= 2 or <= -2
+                        // note: range.last has already been adjusted by kotlin itself to actually be the last value of the sequence
+                        asmgen.out("""
+                            lda  #<${range.first}
+                            ldy  #>${range.first}
+                            sta  $varname
+                            sty  $varname+1
+$loopLabel""")
+                        asmgen.translate(stmt.statements)
+                        asmgen.out("""
+                            lda  $varname
+                            cmp  #<${range.last}
+                            bne  +
+                            lda  $varname+1
+                            cmp  #>${range.last}
+                            bne  +
+                            beq  $endLabel
++                           lda  $varname
+                            clc
+                            adc  #<${range.step}
+                            sta  $varname
+                            lda  $varname+1
+                            adc  #>${range.step}
+                            sta  $varname+1""")
+                        asmgen.jmp(loopLabel)
+                        asmgen.out(endLabel)
+                    }
+                }
+            }
+            else -> throw AssemblyError("range expression can only be byte or word")
+        }
+        asmgen.loopEndLabels.pop()
+    }
+
+    private fun translateForSimpleByteRangeAsc(stmt: PtForLoop, range: IntProgression) {
+        val loopLabel = asmgen.makeLabel("for_loop")
+        val endLabel = asmgen.makeLabel("for_end")
+        asmgen.loopEndLabels.push(endLabel)
+        val varname = asmgen.asmVariableName(stmt.variable)
+        asmgen.out("""
+                lda  #${range.first}
+                sta  $varname
+$loopLabel""")
+        asmgen.translate(stmt.statements)
+        if (range.last == 255) {
+            asmgen.out("""
+                inc  $varname
+                bne  $loopLabel
+$endLabel""")
+        } else {
+            asmgen.out("""
+                inc  $varname
+                lda  $varname
+                cmp  #${range.last+1}
+                bne  $loopLabel
+$endLabel""")
+        }
+        asmgen.loopEndLabels.pop()
+    }
+
+    private fun translateForSimpleByteRangeDesc(stmt: PtForLoop, range: IntProgression) {
+        val loopLabel = asmgen.makeLabel("for_loop")
+        val endLabel = asmgen.makeLabel("for_end")
+        asmgen.loopEndLabels.push(endLabel)
+        val varname = asmgen.asmVariableName(stmt.variable)
+        asmgen.out("""
+                    lda  #${range.first}
+                    sta  $varname
+$loopLabel""")
+        asmgen.translate(stmt.statements)
+        when (range.last) {
+            0 -> {
+                asmgen.out("""
+                    lda  $varname
+                    beq  $endLabel
+                    dec  $varname""")
+                asmgen.jmp(loopLabel)
+                asmgen.out(endLabel)
+            }
+            1 -> {
+                asmgen.out("""
+                    dec  $varname
+                    bne  $loopLabel
+$endLabel""")
+            }
+            else -> {
+                asmgen.out("""
+                    dec  $varname
+                    lda  $varname
+                    cmp  #${range.last-1}
+                    bne  $loopLabel
+$endLabel""")
+            }
+        }
+        asmgen.loopEndLabels.pop()
+    }
+
+    private fun translateForSimpleWordRangeAsc(stmt: PtForLoop, range: IntProgression) {
+        val loopLabel = asmgen.makeLabel("for_loop")
+        val endLabel = asmgen.makeLabel("for_end")
+        asmgen.loopEndLabels.push(endLabel)
+        val varname = asmgen.asmVariableName(stmt.variable)
+        asmgen.out("""
+            lda  #<${range.first}
+            ldy  #>${range.first}
+            sta  $varname
+            sty  $varname+1
+$loopLabel""")
+        asmgen.translate(stmt.statements)
+        asmgen.out("""
+            lda  $varname
+            cmp  #<${range.last}
+            bne  +
+            lda  $varname+1
+            cmp  #>${range.last}
+            beq  $endLabel
++           inc  $varname
+            bne  $loopLabel
+            inc  $varname+1""")
+        asmgen.jmp(loopLabel)
+        asmgen.out(endLabel)
+        asmgen.loopEndLabels.pop()
+    }
+
+    private fun translateForSimpleWordRangeDesc(stmt: PtForLoop, range: IntProgression) {
+        val loopLabel = asmgen.makeLabel("for_loop")
+        val endLabel = asmgen.makeLabel("for_end")
+        asmgen.loopEndLabels.push(endLabel)
+        val varname = asmgen.asmVariableName(stmt.variable)
+        asmgen.out("""
+            lda  #<${range.first}
+            ldy  #>${range.first}
+            sta  $varname
+            sty  $varname+1
+$loopLabel""")
+        asmgen.translate(stmt.statements)
+        asmgen.out("""
+            lda  $varname
+            cmp  #<${range.last}
+            bne  +
+            lda  $varname+1
+            cmp  #>${range.last}
+            beq  $endLabel
++           lda  $varname
+            bne  +
+            dec  $varname+1
++           dec  $varname""")
+        asmgen.jmp(loopLabel)
+        asmgen.out(endLabel)
+        asmgen.loopEndLabels.pop()
+    }
+
+    private fun assignLoopvarWord(stmt: PtForLoop, range: PtRange) =
+        asmgen.assignExpressionToVariable(
+            range.from,
+            asmgen.asmVariableName(stmt.variable),
+            stmt.variable.type)
+}

codeGenCpu6502/src/prog8/codegen/cpu6502/FunctionCallAsmGen.kt

@@ -0,0 +1,243 @@
+package prog8.codegen.cpu6502
+
+import prog8.code.ast.*
+import prog8.code.core.*
+import prog8.codegen.cpu6502.assignment.AsmAssignSource
+import prog8.codegen.cpu6502.assignment.AsmAssignTarget
+import prog8.codegen.cpu6502.assignment.AsmAssignment
+import prog8.codegen.cpu6502.assignment.TargetStorageKind
+
+
+internal class FunctionCallAsmGen(private val program: PtProgram, private val asmgen: AsmGen6502Internal) {
+
+    internal fun translateFunctionCallStatement(stmt: PtFunctionCall) {
+        translateFunctionCall(stmt)
+        // just ignore any result values from the function call.
+    }
+
+    internal fun optimizeIntArgsViaRegisters(sub: PtSub) =
+        (sub.parameters.size==1 && sub.parameters[0].type in IntegerDatatypesWithBoolean)
+                || (sub.parameters.size==2 && sub.parameters[0].type in ByteDatatypesWithBoolean && sub.parameters[1].type in ByteDatatypesWithBoolean)
+
+    internal fun translateFunctionCall(call: PtFunctionCall) {
+        // Output only the code to set up the parameters and perform the actual call
+        // NOTE: does NOT output the code to deal with the result values!
+        // NOTE: does NOT output code to save/restore the X register for this call! Every caller should deal with this in their own way!!
+        //       (you can use subroutine.shouldSaveX() and saveX()/restoreX() routines as a help for this)
+
+        val symbol = asmgen.symbolTable.lookup(call.name)
+        val sub = symbol?.astNode as IPtSubroutine
+        val subAsmName = asmgen.asmSymbolName(call.name)
+
+        if(sub is PtAsmSub) {
+            argumentsViaRegisters(sub, call)
+            if (sub.inline) {
+                // inline the subroutine. (regardless of optimization settings!)
+                // we do this by copying the subroutine's statements at the call site.
+                // NOTE: *if* there is a return statement, it will be the only one, and the very last statement of the subroutine
+                // (this condition has been enforced by an ast check earlier)
+                asmgen.out("  \t; inlined routine follows: ${sub.name}")
+                sub.children.forEach { asmgen.translate(it as PtInlineAssembly) }
+                asmgen.out("  \t; inlined routine end: ${sub.name}")
+            } else {
+                asmgen.out("  jsr  $subAsmName")
+            }
+        }
+        else if(sub is PtSub) {
+            if(optimizeIntArgsViaRegisters(sub)) {
+                if(sub.parameters.size==1) {
+                    val register = if (sub.parameters[0].type in ByteDatatypesWithBoolean) RegisterOrPair.A else RegisterOrPair.AY
+                    argumentViaRegister(sub, IndexedValue(0, sub.parameters[0]), call.args[0], register)
+                } else {
+                    // 2 byte params, second in Y, first in A
+                    argumentViaRegister(sub, IndexedValue(0, sub.parameters[0]), call.args[0], RegisterOrPair.A)
+                    if(asmgen.needAsaveForExpr(call.args[1]))
+                        asmgen.out("  pha")
+                    argumentViaRegister(sub, IndexedValue(1, sub.parameters[1]), call.args[1], RegisterOrPair.Y)
+                    if(asmgen.needAsaveForExpr(call.args[1]))
+                        asmgen.out("  pla")
+                }
+            } else {
+                // arguments via variables
+                for(arg in sub.parameters.withIndex().zip(call.args))
+                    argumentViaVariable(sub, arg.first.value, arg.second)
+            }
+            asmgen.out("  jsr  $subAsmName")
+        }
+        else throw AssemblyError("invalid sub type")
+
+        // remember: dealing with the X register and/or dealing with return values is the responsibility of the caller
+    }
+
+
+    private fun usesOtherRegistersWhileEvaluating(arg: PtExpression): Boolean {
+        return when(arg) {
+            is PtBuiltinFunctionCall -> {
+                if (arg.name == "lsb" || arg.name == "msb")
+                    return usesOtherRegistersWhileEvaluating(arg.args[0])
+                if (arg.name == "mkword")
+                    return usesOtherRegistersWhileEvaluating(arg.args[0]) || usesOtherRegistersWhileEvaluating(arg.args[1])
+                return !arg.isSimple()
+            }
+            is PtAddressOf -> false
+            is PtIdentifier -> false
+            is PtIrRegister -> false
+            is PtMemoryByte -> true     // TODO might not actually need extra registers if the value has to end up in A
+            is PtNumber -> false
+            is PtBool -> false
+            else -> true
+        }
+    }
+
+    private fun argumentsViaRegisters(sub: PtAsmSub, call: PtFunctionCall) {
+        val registersUsed = mutableListOf<RegisterOrStatusflag>()
+
+        fun usedA() = registersUsed.any {it.registerOrPair==RegisterOrPair.A || it.registerOrPair==RegisterOrPair.AX || it.registerOrPair==RegisterOrPair.AY}
+        fun usedX() = registersUsed.any {it.registerOrPair==RegisterOrPair.X || it.registerOrPair==RegisterOrPair.AX || it.registerOrPair==RegisterOrPair.XY}
+        fun usedY() = registersUsed.any {it.registerOrPair==RegisterOrPair.Y || it.registerOrPair==RegisterOrPair.AY || it.registerOrPair==RegisterOrPair.XY}
+
+        if(sub.parameters.size==1) {
+            argumentViaRegister(sub, IndexedValue(0, sub.parameters.single().second), call.args[0])
+        } else {
+            val optimalEvalOrder = asmsub6502ArgsEvalOrder(sub)
+            optimalEvalOrder.forEach {
+                val param = sub.parameters[it]
+                val arg = call.args[it]
+                registersUsed += if(usesOtherRegistersWhileEvaluating(arg)) {
+                    if(!registersUsed.any{it.statusflag!=null || it.registerOrPair in CpuRegisters})
+                        argumentViaRegister(sub, IndexedValue(it, param.second), arg)
+                    else if(registersUsed.any {it.statusflag!=null}) {
+                        throw AssemblyError("call argument evaluation problem: can't save cpu statusregister parameter ${call.position}")
+                    }
+                    else {
+                        if(usedX()) asmgen.saveRegisterStack(CpuRegister.X, usedA())
+                        if(usedY()) asmgen.saveRegisterStack(CpuRegister.Y, usedA())
+                        if(usedA()) asmgen.saveRegisterStack(CpuRegister.A, usedA())
+                        val used = argumentViaRegister(sub, IndexedValue(it, param.second), arg)
+                        if(usedA()) asmgen.restoreRegisterStack(CpuRegister.A, false)
+                        if(usedY()) asmgen.restoreRegisterStack(CpuRegister.Y, true)
+                        if(usedX()) asmgen.restoreRegisterStack(CpuRegister.X, true)
+                        used
+                    }
+                } else {
+                    argumentViaRegister(sub, IndexedValue(it, param.second), arg)
+                }
+            }
+        }
+    }
+
+    private fun argumentViaVariable(sub: PtSub, parameter: PtSubroutineParameter, value: PtExpression) {
+        // pass parameter via a regular variable (not via registers)
+        if(!isArgumentTypeCompatible(value.type, parameter.type))
+            throw AssemblyError("argument type incompatible")
+
+        val varName = asmgen.asmVariableName(sub.scopedName + "." + parameter.name)
+        asmgen.assignExpressionToVariable(value, varName, parameter.type)
+    }
+
+    private fun argumentViaRegister(sub: IPtSubroutine, parameter: IndexedValue<PtSubroutineParameter>, value: PtExpression, registerOverride: RegisterOrPair? = null): RegisterOrStatusflag {
+        // pass argument via a register parameter
+        if(!isArgumentTypeCompatible(value.type, parameter.value.type))
+            throw AssemblyError("argument type incompatible")
+
+        val paramRegister: RegisterOrStatusflag = when(sub) {
+            is PtAsmSub -> if(registerOverride==null) sub.parameters[parameter.index].first else RegisterOrStatusflag(registerOverride, null)
+            is PtSub -> RegisterOrStatusflag(registerOverride!!, null)
+        }
+        val statusflag = paramRegister.statusflag
+        val register = paramRegister.registerOrPair
+        val requiredDt = parameter.value.type
+        if(requiredDt!=value.type) {
+            if(value.type largerThan requiredDt)
+                throw AssemblyError("can only convert byte values to word param types")
+        }
+        if (statusflag!=null) {
+            if(requiredDt!=value.type)
+                throw AssemblyError("for statusflag, byte or bool value is required")
+            if (statusflag == Statusflag.Pc) {
+                // this boolean 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 PtNumber -> {
+                        val carrySet = value.number.toInt() != 0
+                        asmgen.out(if(carrySet) "  sec" else "  clc")
+                    }
+                    is PtBool -> {
+                        asmgen.out(if(value.value) "  sec" else "  clc")
+                    }
+                    is PtIdentifier -> {
+                        val sourceName = asmgen.asmVariableName(value)
+                        // note: cannot use X register here to store A because it might be used for other arguments
+                        asmgen.out("""
+                            pha
+                            clc
+                            lda  $sourceName
+                            beq  +
+                            sec  
++                           pla""")
+                    }
+                    else -> {
+                        asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
+                        asmgen.out("  ror  a")
+                    }
+                }
+            } else throw AssemblyError("can only use Carry as status flag parameter")
+            return RegisterOrStatusflag(null, statusflag)
+        }
+        else {
+            // via register or register pair
+            register!!
+            if(requiredDt largerThan value.type) {
+                // we need to sign extend the source, do this via temporary word variable
+                asmgen.assignExpressionToVariable(value, "P8ZP_SCRATCH_W1", DataType.UBYTE)
+                asmgen.signExtendVariableLsb("P8ZP_SCRATCH_W1", value.type)
+                asmgen.assignVariableToRegister("P8ZP_SCRATCH_W1", register, null, Position.DUMMY)
+            } else {
+                val scope = value.definingISub()
+                val target: AsmAssignTarget =
+                    if(parameter.value.type in ByteDatatypes && (register==RegisterOrPair.AX || register == RegisterOrPair.AY || register==RegisterOrPair.XY || register in Cx16VirtualRegisters))
+                        AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, parameter.value.type, scope, value.position, register = register)
+                    else {
+                        val signed = parameter.value.type == DataType.BYTE || parameter.value.type == DataType.WORD
+                        AsmAssignTarget.fromRegisters(register, signed, value.position, scope, asmgen)
+                    }
+                val src = if(value.type in PassByReferenceDatatypes) {
+                    if(value is PtIdentifier) {
+                        val addr = PtAddressOf(Position.DUMMY)
+                        addr.add(value)
+                        addr.parent = sub as PtNode
+                        AsmAssignSource.fromAstSource(addr, program, asmgen).adjustSignedUnsigned(target)
+                    } else {
+                        AsmAssignSource.fromAstSource(value, program, asmgen).adjustSignedUnsigned(target)
+                    }
+                } else {
+                    AsmAssignSource.fromAstSource(value, program, asmgen).adjustSignedUnsigned(target)
+                }
+                asmgen.translateNormalAssignment(AsmAssignment(src, target, program.memsizer, Position.DUMMY), scope)
+            }
+            return RegisterOrStatusflag(register, null)
+        }
+    }
+
+    private fun isArgumentTypeCompatible(argType: DataType, paramType: DataType): Boolean {
+        if(argType isAssignableTo paramType)
+            return true
+        if(argType==DataType.BOOL && paramType==DataType.BOOL)
+            return true
+        if(argType in ByteDatatypes && paramType in ByteDatatypes)
+            return true
+        if(argType in WordDatatypes && paramType in WordDatatypes)
+            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
+    }
+}
+
+

codeGenCpu6502/src/prog8/codegen/cpu6502/ProgramAndVarsGen.kt

@@ -0,0 +1,831 @@
+package prog8.codegen.cpu6502
+
+import prog8.code.*
+import prog8.code.ast.*
+import prog8.code.core.*
+import prog8.codegen.cpu6502.assignment.AsmAssignTarget
+import prog8.codegen.cpu6502.assignment.TargetStorageKind
+import java.time.LocalDate
+import java.time.LocalDateTime
+import kotlin.math.absoluteValue
+
+/**
+ * Generates the main parts of the program:
+ *  - entry/exit code
+ *  - initialization routines
+ *  - blocks
+ *  - subroutines
+ *  - all variables (note: VarDecl ast nodes are *NOT* used anymore for this! now uses IVariablesAndConsts data tables!)
+ */
+internal class ProgramAndVarsGen(
+    val program: PtProgram,
+    val options: CompilationOptions,
+    val errors: IErrorReporter,
+    private val symboltable: SymbolTable,
+    private val functioncallAsmGen: FunctionCallAsmGen,
+    private val asmgen: AsmGen6502Internal,
+    private val allocator: VariableAllocator,
+    private val zeropage: Zeropage
+) {
+    private val compTarget = options.compTarget
+    private val blockVariableInitializers = program.allBlocks().associateWith { it.children.filterIsInstance<PtAssignment>() }
+
+    internal fun generate() {
+        header()
+        val allBlocks = program.allBlocks()
+
+        if(allBlocks.first().name != "p8b_main" && allBlocks.first().name != "main")
+            throw AssemblyError("first block should be 'main' or 'p8b_main'")
+
+        if(errors.noErrors())  {
+            program.allBlocks().forEach { block2asm(it) }
+
+            // the global list of all floating point constants for the whole program
+            asmgen.out("; global float constants")
+            for (flt in allocator.globalFloatConsts) {
+                val floatFill = compTarget.machine.getFloatAsmBytes(flt.key)
+                val floatvalue = flt.key
+                asmgen.out("${flt.value}\t.byte  $floatFill  ; float $floatvalue")
+            }
+
+            memorySlabs()
+            tempVars()
+            footer()
+        }
+    }
+
+    private fun header() {
+        val ourName = this.javaClass.name
+        val cpu = when(compTarget.machine.cpu) {
+            CpuType.CPU6502 -> "6502"
+            CpuType.CPU65c02 -> "w65c02"
+            else -> "unsupported"
+        }
+
+        asmgen.out("; $cpu assembly code for '${program.name}'")
+        asmgen.out("; generated by $ourName on ${LocalDateTime.now().withNano(0)}")
+        asmgen.out("; assembler syntax is for the 64tasm cross-assembler")
+        asmgen.out("; output options: output=${options.output} launcher=${options.launcher} zp=${options.zeropage}")
+        asmgen.out("")
+        asmgen.out(".cpu  '$cpu'\n.enc  'none'")
+
+        // the global prog8 variables needed
+        val zp = zeropage
+        asmgen.out("P8ZP_SCRATCH_B1 = ${zp.SCRATCH_B1}")
+        asmgen.out("P8ZP_SCRATCH_REG = ${zp.SCRATCH_REG}")
+        asmgen.out("P8ZP_SCRATCH_W1 = ${zp.SCRATCH_W1}    ; word")
+        asmgen.out("P8ZP_SCRATCH_W2 = ${zp.SCRATCH_W2}    ; word")
+        asmgen.out(".weak")   // hack to allow user to override the following two with command line redefinition (however, just use '-esa' command line option instead!)
+        asmgen.out(".endweak")
+
+        if(options.symbolDefs.isNotEmpty()) {
+            asmgen.out("; -- user supplied symbols on the command line")
+            for((name, value) in options.symbolDefs) {
+                asmgen.out("$name = $value")
+            }
+        }
+
+        when(options.output) {
+            OutputType.RAW -> {
+                asmgen.out("; ---- raw assembler program ----")
+                asmgen.out("* = ${options.loadAddress.toHex()}")
+            }
+            OutputType.PRG -> {
+                when(options.launcher) {
+                    CbmPrgLauncherType.BASIC -> {
+                        if (options.loadAddress != options.compTarget.machine.PROGRAM_LOAD_ADDRESS) {
+                            errors.err("BASIC output must have load address ${options.compTarget.machine.PROGRAM_LOAD_ADDRESS.toHex()}", program.position)
+                        }
+                        asmgen.out("; ---- basic program with sys call ----")
+                        asmgen.out("* = ${options.loadAddress.toHex()}")
+                        val year = LocalDate.now().year
+                        asmgen.out("  .word  (+), $year")
+                        asmgen.out("  .null  $9e, format(' %d ', prog8_entrypoint), $3a, $8f, ' prog8'")
+                        asmgen.out("+\t.word  0")
+                        asmgen.out("prog8_entrypoint\t; assembly code starts here")
+                        if(!options.noSysInit)
+                            asmgen.out("  jsr  sys.init_system")
+                        asmgen.out("  jsr  sys.init_system_phase2")
+                    }
+                    CbmPrgLauncherType.NONE -> {
+                        asmgen.out("; ---- program without basic sys call ----")
+                        asmgen.out("* = ${options.loadAddress.toHex()}")
+                        if(!options.noSysInit)
+                            asmgen.out("  jsr  sys.init_system")
+                        asmgen.out("  jsr  sys.init_system_phase2")
+                    }
+                }
+            }
+            OutputType.XEX -> {
+                asmgen.out("; ---- atari xex program ----")
+                asmgen.out("* = ${options.loadAddress.toHex()}")
+                if(!options.noSysInit)
+                    asmgen.out("  jsr  sys.init_system")
+                asmgen.out("  jsr  sys.init_system_phase2")
+            }
+        }
+
+        if(options.zeropage !in arrayOf(ZeropageType.BASICSAFE, ZeropageType.DONTUSE)) {
+            asmgen.out("""
+                ; zeropage is clobbered so we need to reset the machine at exit
+                lda  #>sys.reset_system
+                pha
+                lda  #<sys.reset_system
+                pha""")
+        }
+
+        when(compTarget.name) {
+            "cx16" -> {
+                if(options.floats)
+                    asmgen.out("  lda  #4 |  sta  $01")    // to use floats, make sure Basic rom is banked in
+                asmgen.out("  jsr  p8b_main.p8s_start")
+                asmgen.out("  jmp  sys.cleanup_at_exit")
+            }
+            "c64" -> {
+                asmgen.out("  jsr  p8b_main.p8s_start |  lda  #31 |  sta  $01")
+                asmgen.out("  jmp  sys.cleanup_at_exit")
+            }
+            "c128" -> {
+                asmgen.out("  jsr  p8b_main.p8s_start |  lda  #0 |  sta ${"$"}ff00")
+                asmgen.out("  jmp  sys.cleanup_at_exit")
+            }
+            else -> asmgen.jmp("p8b_main.p8s_start")
+        }
+    }
+
+    private fun memorySlabs() {
+        if(symboltable.allMemorySlabs.isNotEmpty()) {
+            asmgen.out("; memory slabs\n  .section slabs_BSS")
+            asmgen.out("prog8_slabs\t.block")
+            for (slab in symboltable.allMemorySlabs) {
+                if (slab.align > 1u)
+                    asmgen.out("\t.align  ${slab.align.toHex()}")
+                asmgen.out("${slab.name}\t.fill  ${slab.size}")
+            }
+            asmgen.out("\t.bend\n  .send slabs_BSS")
+        }
+    }
+
+    private fun tempVars() {
+        asmgen.out("; expression temp vars\n  .section BSS")
+        for((dt, count) in asmgen.tempVarsCounters) {
+            if(count>0) {
+                for(num in 1..count) {
+                    val name = asmgen.buildTempVarName(dt, num)
+                    when (dt) {
+                        DataType.BOOL  -> asmgen.out("$name    .byte  ?")
+                        DataType.BYTE  -> asmgen.out("$name    .char  ?")
+                        DataType.UBYTE -> asmgen.out("$name    .byte  ?")
+                        DataType.WORD  -> asmgen.out("$name    .sint  ?")
+                        DataType.UWORD -> asmgen.out("$name    .word  ?")
+                        DataType.FLOAT -> asmgen.out("$name    .fill  ${options.compTarget.machine.FLOAT_MEM_SIZE}")
+                        else -> throw AssemblyError("weird dt for extravar $dt")
+                    }
+                }
+            }
+        }
+        asmgen.out("  .send BSS")
+    }
+
+    private fun footer() {
+        var relocateBssVars = false
+        var relocateBssSlabs = false
+        var relocatedBssStart = 0u
+        var relocatedBssEnd = 0u
+
+        if(options.varsGolden) {
+            if(options.compTarget.machine.BSSGOLDENRAM_START == 0u ||
+                options.compTarget.machine.BSSGOLDENRAM_END == 0u ||
+                options.compTarget.machine.BSSGOLDENRAM_END <= options.compTarget.machine.BSSGOLDENRAM_START) {
+                throw AssemblyError("current compilation target hasn't got the golden ram area properly defined or it is simply not available")
+            }
+            relocateBssVars = true
+            relocatedBssStart = options.compTarget.machine.BSSGOLDENRAM_START
+            relocatedBssEnd = options.compTarget.machine.BSSGOLDENRAM_END
+        }
+        else if(options.varsHighBank!=null) {
+            if(options.compTarget.machine.BSSHIGHRAM_START == 0u ||
+                options.compTarget.machine.BSSHIGHRAM_END == 0u ||
+                options.compTarget.machine.BSSHIGHRAM_END <= options.compTarget.machine.BSSHIGHRAM_START) {
+                throw AssemblyError("current compilation target hasn't got the high ram area properly defined or it is simply not available")
+            }
+            if(options.slabsHighBank!=null && options.varsHighBank!=options.slabsHighBank)
+                throw AssemblyError("slabs and vars high bank must be the same")
+            relocateBssVars = true
+            relocatedBssStart = options.compTarget.machine.BSSHIGHRAM_START
+            relocatedBssEnd = options.compTarget.machine.BSSHIGHRAM_END
+        }
+
+        if(options.slabsGolden) {
+            if(options.compTarget.machine.BSSGOLDENRAM_START == 0u ||
+                options.compTarget.machine.BSSGOLDENRAM_END == 0u ||
+                options.compTarget.machine.BSSGOLDENRAM_END <= options.compTarget.machine.BSSGOLDENRAM_START) {
+                throw AssemblyError("current compilation target hasn't got the golden ram area properly defined or it is simply not available")
+            }
+            relocateBssSlabs = true
+            relocatedBssStart = options.compTarget.machine.BSSGOLDENRAM_START
+            relocatedBssEnd = options.compTarget.machine.BSSGOLDENRAM_END
+        }
+        else if(options.slabsHighBank!=null) {
+            if(options.compTarget.machine.BSSHIGHRAM_START == 0u ||
+                options.compTarget.machine.BSSHIGHRAM_END == 0u ||
+                options.compTarget.machine.BSSHIGHRAM_END <= options.compTarget.machine.BSSHIGHRAM_START) {
+                throw AssemblyError("current compilation target hasn't got the high ram area properly defined or it is simply not available")
+            }
+            if(options.varsHighBank!=null && options.varsHighBank!=options.slabsHighBank)
+                throw AssemblyError("slabs and vars high bank must be the same")
+            relocateBssSlabs = true
+            relocatedBssStart = options.compTarget.machine.BSSHIGHRAM_START
+            relocatedBssEnd = options.compTarget.machine.BSSHIGHRAM_END
+        }
+
+        asmgen.out("; bss sections")
+        asmgen.out("PROG8_VARSHIGH_RAMBANK = ${options.varsHighBank ?: 1}")
+        if(relocateBssVars) {
+            if(!relocateBssSlabs)
+                asmgen.out("  .dsection slabs_BSS")
+            asmgen.out("prog8_program_end\t; end of program label for progend()")
+            asmgen.out("  * = ${relocatedBssStart.toHex()}")
+            asmgen.out("prog8_bss_section_start")
+            asmgen.out("  .dsection BSS")
+            if(relocateBssSlabs)
+                asmgen.out("  .dsection slabs_BSS")
+            asmgen.out("  .cerror * > ${relocatedBssEnd.toHex()}, \"too many variables/data for BSS section\"")
+            asmgen.out("prog8_bss_section_size = * - prog8_bss_section_start")
+        } else {
+            asmgen.out("prog8_bss_section_start")
+            asmgen.out("  .dsection BSS")
+            asmgen.out("prog8_bss_section_size = * - prog8_bss_section_start")
+            if(!relocateBssSlabs)
+                asmgen.out("  .dsection slabs_BSS")
+            asmgen.out("prog8_program_end\t; end of program label for progend()")
+            if(relocateBssSlabs) {
+                asmgen.out("  * = ${relocatedBssStart.toHex()}")
+                asmgen.out("  .dsection slabs_BSS")
+                asmgen.out("  .cerror * > ${relocatedBssEnd.toHex()}, \"too many data for slabs_BSS section\"")
+            }
+        }
+    }
+
+    private fun block2asm(block: PtBlock) {
+        asmgen.out("")
+        asmgen.out("; ---- block: '${block.name}' ----")
+        if(block.options.address!=null)
+            asmgen.out("* = ${block.options.address!!.toHex()}")
+        else {
+            if(block.options.alignment==PtBlock.BlockAlignment.WORD)
+                asmgen.out("\t.align 2")
+            else if(block.options.alignment==PtBlock.BlockAlignment.PAGE)
+                asmgen.out("\t.align $100")
+        }
+
+        asmgen.out("${block.name}\t" + (if(block.options.forceOutput) ".block" else ".proc"))
+        asmgen.outputSourceLine(block)
+
+        createBlockVariables(block)
+        asmsubs2asm(block.children)
+
+        asmgen.out("")
+
+        val initializers = blockVariableInitializers.getValue(block)
+        val notInitializers = block.children.filterNot { it in initializers }
+        notInitializers.forEach { asmgen.translate(it) }
+
+        // generate subroutine to initialize block-level (global) variables
+        if (initializers.isNotEmpty()) {
+            asmgen.out("prog8_init_vars\t.block")
+            initializers.forEach { assign ->
+                if((assign.value as? PtNumber)?.number != 0.0 || allocator.isZpVar(assign.target.identifier!!.name))
+                    asmgen.translate(assign)
+                // the other variables that should be set to zero are done so as part of the BSS section.
+            }
+            asmgen.out("  rts\n  .bend")
+        }
+
+        asmgen.out(if(block.options.forceOutput) "\n\t.bend" else "\n\t.pend")
+    }
+
+    private fun getVars(scope: StNode): Map<String, StNode> =
+        scope.children.filter { it.value.type in arrayOf(StNodeType.STATICVAR, StNodeType.CONSTANT, StNodeType.MEMVAR) }
+
+    private fun createBlockVariables(block: PtBlock) {
+        val scope = symboltable.lookupUnscopedOrElse(block.name) { throw AssemblyError("lookup") }
+        require(scope.type==StNodeType.BLOCK)
+        val varsInBlock = getVars(scope)
+
+        // Zeropage Variables
+        val varnames = varsInBlock.filter { it.value.type==StNodeType.STATICVAR }.map { it.value.scopedName }.toSet()
+        zeropagevars2asm(varnames)
+
+        // MemDefs and Consts
+        val mvs = varsInBlock
+            .filter { it.value.type==StNodeType.MEMVAR }
+            .map { it.value as StMemVar }
+        val consts = varsInBlock
+            .filter { it.value.type==StNodeType.CONSTANT }
+            .map { it.value as StConstant }
+        memdefsAndConsts2asm(mvs, consts)
+
+        // normal statically allocated variables
+        val variables = varsInBlock
+            .filter { it.value.type==StNodeType.STATICVAR && !allocator.isZpVar(it.value.scopedName) }
+            .map { it.value as StStaticVariable }
+        nonZpVariables2asm(variables)
+    }
+
+    internal fun translateAsmSubroutine(sub: PtAsmSub) {
+        if(sub.inline) {
+            return      // subroutine gets inlined at call site.
+        }
+
+        asmgen.out("")
+
+        val asmStartScope: String
+        val asmEndScope: String
+        if(sub.definingBlock()!!.options.forceOutput) {
+            asmStartScope = ".block"
+            asmEndScope = ".bend"
+        } else {
+            asmStartScope = ".proc"
+            asmEndScope = ".pend"
+        }
+
+        if(sub.address!=null)
+            return  // already done at the memvars section
+
+        // asmsub with most likely just an inline asm in it
+        asmgen.out("${sub.name}\t$asmStartScope")
+        sub.children.forEach { asmgen.translate(it) }
+        asmgen.out("  $asmEndScope")
+    }
+
+
+    internal fun translateSubroutine(sub: PtSub) {
+        asmgen.out("")
+
+        val asmStartScope: String
+        val asmEndScope: String
+        if(sub.definingBlock()!!.options.forceOutput) {
+            asmStartScope = ".block"
+            asmEndScope = ".bend"
+        } else {
+            asmStartScope = ".proc"
+            asmEndScope = ".pend"
+        }
+
+        asmgen.out("${sub.name}\t$asmStartScope")
+
+        val scope = symboltable.lookupOrElse(sub.scopedName) {
+            throw AssemblyError("lookup ${sub.scopedName}")
+        }
+        require(scope.type==StNodeType.SUBROUTINE)
+        val varsInSubroutine = getVars(scope)
+
+        // Zeropage Variables
+        val varnames = varsInSubroutine.filter { it.value.type==StNodeType.STATICVAR }.map { it.value.scopedName }.toSet()
+        zeropagevars2asm(varnames)
+
+        // MemDefs and Consts
+        val mvs = varsInSubroutine
+            .filter { it.value.type==StNodeType.MEMVAR }
+            .map { it.value as StMemVar }
+        val consts = varsInSubroutine
+            .filter { it.value.type==StNodeType.CONSTANT }
+            .map { it.value as StConstant }
+        memdefsAndConsts2asm(mvs, consts)
+
+        asmsubs2asm(sub.children)
+
+        // the main.start subroutine is the program's entrypoint and should perform some initialization logic
+        if((sub.name=="start" || sub.name=="p8s_start") && (sub.definingBlock()!!.name=="main" || sub.definingBlock()!!.name=="p8b_main"))
+            entrypointInitialization()
+
+        if(functioncallAsmGen.optimizeIntArgsViaRegisters(sub)) {
+            asmgen.out("; simple int arg(s) passed via register(s)")
+            if(sub.parameters.size==1) {
+                val dt = sub.parameters[0].type
+                val target = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, dt, sub, sub.parameters[0].position, variableAsmName = sub.parameters[0].name)
+                if(dt in ByteDatatypesWithBoolean)
+                    asmgen.assignRegister(RegisterOrPair.A, target)
+                else
+                    asmgen.assignRegister(RegisterOrPair.AY, target)
+            } else {
+                require(sub.parameters.size==2)
+                // 2 simple byte args, first in A, second in Y
+                val target1 = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, sub.parameters[0].type, sub, sub.parameters[0].position, variableAsmName = sub.parameters[0].name)
+                val target2 = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, sub.parameters[1].type, sub, sub.parameters[1].position, variableAsmName = sub.parameters[1].name)
+                asmgen.assignRegister(RegisterOrPair.A, target1)
+                asmgen.assignRegister(RegisterOrPair.Y, target2)
+            }
+        }
+
+        asmgen.out("; statements")
+        sub.children.forEach { asmgen.translate(it) }
+
+        asmgen.out("; variables")
+        asmgen.out("    .section BSS")
+        val asmGenInfo = asmgen.subroutineExtra(sub)
+        for((dt, name, addr) in asmGenInfo.extraVars) {
+            if(addr!=null)
+                asmgen.out("$name = $addr")
+            else when(dt) {
+                DataType.UBYTE -> asmgen.out("$name    .byte  ?")
+                DataType.UWORD -> asmgen.out("$name    .word  ?")
+                DataType.FLOAT -> asmgen.out("$name    .fill  ${options.compTarget.machine.FLOAT_MEM_SIZE}")
+                else -> throw AssemblyError("weird dt for extravar $dt")
+            }
+        }
+        if(asmGenInfo.usedFloatEvalResultVar1)
+            asmgen.out("$subroutineFloatEvalResultVar1    .fill  ${options.compTarget.machine.FLOAT_MEM_SIZE}")
+        if(asmGenInfo.usedFloatEvalResultVar2)
+            asmgen.out("$subroutineFloatEvalResultVar2    .fill  ${options.compTarget.machine.FLOAT_MEM_SIZE}")
+        asmgen.out("  .send BSS")
+
+        // normal statically allocated variables
+        val variables = varsInSubroutine
+            .filter { it.value.type==StNodeType.STATICVAR && !allocator.isZpVar(it.value.scopedName) }
+            .map { it.value as StStaticVariable }
+        nonZpVariables2asm(variables)
+
+        asmgen.out("  $asmEndScope")
+    }
+
+    private fun entrypointInitialization() {
+        asmgen.out("; program startup initialization")
+        asmgen.out("  cld |  tsx |  stx  prog8_lib.orig_stackpointer    ; required for sys.exit()")
+        // set full BSS area to zero
+        asmgen.out("""
+    .if  prog8_bss_section_size>0
+    ; reset all variables in BSS section to zero
+	lda  #<prog8_bss_section_start
+	ldy  #>prog8_bss_section_start
+	sta  P8ZP_SCRATCH_W1
+	sty  P8ZP_SCRATCH_W1+1
+	ldx  #<prog8_bss_section_size
+	ldy  #>prog8_bss_section_size
+	lda  #0
+	jsr  prog8_lib.memset
+    .endif""")
+
+        blockVariableInitializers.forEach {
+            if (it.value.isNotEmpty())
+                asmgen.out("  jsr  ${it.key.name}.prog8_init_vars")
+        }
+
+        // string and array variables in zeropage that have initializer value, should be initialized
+        val stringVarsWithInitInZp = getZpStringVarsWithInitvalue()
+        val arrayVarsWithInitInZp = getZpArrayVarsWithInitvalue()
+        if(stringVarsWithInitInZp.isNotEmpty() || arrayVarsWithInitInZp.isNotEmpty()) {
+            asmgen.out("; zp str and array initializations")
+            stringVarsWithInitInZp.forEach {
+                val name = asmgen.asmVariableName(it.name)
+                asmgen.out("""
+                    lda  #<${name}
+                    ldy  #>${name}
+                    sta  P8ZP_SCRATCH_W1
+                    sty  P8ZP_SCRATCH_W1+1
+                    lda  #<${name}_init_value
+                    ldy  #>${name}_init_value
+                    jsr  prog8_lib.strcpy""")
+            }
+            arrayVarsWithInitInZp.forEach {
+                val size = it.alloc.size
+                val name = asmgen.asmVariableName(it.name)
+                asmgen.out("""
+                    lda  #<${name}_init_value
+                    ldy  #>${name}_init_value
+                    sta  cx16.r0
+                    sty  cx16.r0+1
+                    lda  #<${name}
+                    ldy  #>${name}
+                    sta  cx16.r1
+                    sty  cx16.r1+1
+                    lda  #<$size
+                    ldy  #>$size
+                    jsr  sys.memcopy""")
+            }
+            asmgen.out("  jmp  +")
+        }
+
+        stringVarsWithInitInZp.forEach {
+            val varname = asmgen.asmVariableName(it.name)+"_init_value"
+            outputStringvar(varname, it.value.second, it.value.first)
+        }
+
+        arrayVarsWithInitInZp.forEach {
+            val varname = asmgen.asmVariableName(it.name)+"_init_value"
+            arrayVariable2asm(varname, it.alloc.dt, it.value, null)
+        }
+
+        asmgen.out("""+        
+                    clv
+                    clc""")
+    }
+
+    private class ZpStringWithInitial(
+        val name: String,
+        val alloc: MemoryAllocator.VarAllocation,
+        val value: Pair<String, Encoding>
+    )
+
+    private class ZpArrayWithInitial(
+        val name: String,
+        val alloc: MemoryAllocator.VarAllocation,
+        val value: StArray
+    )
+
+    private fun getZpStringVarsWithInitvalue(): Collection<ZpStringWithInitial> {
+        val result = mutableListOf<ZpStringWithInitial>()
+        val vars = allocator.zeropageVars.filter { it.value.dt==DataType.STR }
+        for (variable in vars) {
+            val scopedName = variable.key
+            val svar = symboltable.lookup(scopedName) as? StStaticVariable
+            if(svar?.onetimeInitializationStringValue!=null)
+                result.add(ZpStringWithInitial(scopedName, variable.value, svar.onetimeInitializationStringValue!!))
+        }
+        return result
+    }
+
+    private fun getZpArrayVarsWithInitvalue(): Collection<ZpArrayWithInitial> {
+        val result = mutableListOf<ZpArrayWithInitial>()
+        val vars = allocator.zeropageVars.filter { it.value.dt in ArrayDatatypes }
+        for (variable in vars) {
+            val scopedName = variable.key
+            val svar = symboltable.lookup(scopedName) as? StStaticVariable
+            if(svar?.onetimeInitializationArrayValue!=null)
+                result.add(ZpArrayWithInitial(scopedName, variable.value, svar.onetimeInitializationArrayValue!!))
+        }
+        return result
+    }
+
+    private fun zeropagevars2asm(varNames: Set<String>) {
+        val zpVariables = allocator.zeropageVars.filter { it.key in varNames }.toList().sortedBy { it.second.address }
+        for ((scopedName, zpvar) in zpVariables) {
+            if (scopedName.startsWith("cx16.r"))
+                continue        // The 16 virtual registers of the cx16 are not actual variables in zp, they're memory mapped
+            val variable = symboltable.flat.getValue(scopedName) as StStaticVariable
+            if(variable.dt in SplitWordArrayTypes) {
+                val lsbAddr = zpvar.address
+                val msbAddr = zpvar.address + (zpvar.size/2).toUInt()
+                asmgen.out("${scopedName.substringAfterLast('.')}_lsb \t= $lsbAddr \t; zp ${zpvar.dt} (lsbs)")
+                asmgen.out("${scopedName.substringAfterLast('.')}_msb \t= $msbAddr \t; zp ${zpvar.dt} (msbs)")
+            } else {
+                asmgen.out("${scopedName.substringAfterLast('.')} \t= ${zpvar.address} \t; zp ${zpvar.dt}")
+            }
+        }
+    }
+
+    private fun nonZpVariables2asm(variables: List<StStaticVariable>) {
+        asmgen.out("")
+        val (varsNoInit, varsWithInit) = variables.partition { it.uninitialized }
+        if(varsNoInit.isNotEmpty()) {
+            asmgen.out("; non-zeropage variables without initialization value")
+            asmgen.out("  .section BSS")
+            varsNoInit.sortedWith(compareBy<StStaticVariable> { it.name }.thenBy { it.dt }).forEach {
+                uninitializedVariable2asm(it)
+            }
+            asmgen.out("  .send BSS")
+        }
+
+        if(varsWithInit.isNotEmpty()) {
+            asmgen.out("; non-zeropage variables")
+            val (stringvars, othervars) = varsWithInit.sortedBy { it.name }.partition { it.dt == DataType.STR }
+            stringvars.forEach {
+                outputStringvar(
+                    it.name,
+                    it.onetimeInitializationStringValue!!.second,
+                    it.onetimeInitializationStringValue!!.first
+                )
+            }
+            othervars.sortedBy { it.type }.forEach {
+                staticVariable2asm(it)
+            }
+        }
+    }
+
+    private fun uninitializedVariable2asm(variable: StStaticVariable) {
+        when (variable.dt) {
+            DataType.BOOL, DataType.UBYTE -> asmgen.out("${variable.name}\t.byte  ?")
+            DataType.BYTE -> asmgen.out("${variable.name}\t.char  ?")
+            DataType.UWORD -> asmgen.out("${variable.name}\t.word  ?")
+            DataType.WORD -> asmgen.out("${variable.name}\t.sint  ?")
+            DataType.FLOAT -> asmgen.out("${variable.name}\t.fill  ${compTarget.machine.FLOAT_MEM_SIZE}")
+            in SplitWordArrayTypes -> {
+                val numbytesPerHalf = compTarget.memorySize(variable.dt, variable.length!!) / 2
+                asmgen.out("${variable.name}_lsb\t.fill  $numbytesPerHalf")
+                asmgen.out("${variable.name}_msb\t.fill  $numbytesPerHalf")
+            }
+            in ArrayDatatypes -> {
+                val numbytes = compTarget.memorySize(variable.dt, variable.length!!)
+                asmgen.out("${variable.name}\t.fill  $numbytes")
+            }
+            else -> {
+                throw AssemblyError("weird dt")
+            }
+        }
+    }
+
+    private fun staticVariable2asm(variable: StStaticVariable) {
+        val initialValue: Number =
+            if(variable.onetimeInitializationNumericValue!=null) {
+                if(variable.dt== DataType.FLOAT)
+                    variable.onetimeInitializationNumericValue!!
+                else
+                    variable.onetimeInitializationNumericValue!!.toInt()
+            } else 0
+
+        when (variable.dt) {
+            DataType.BOOL, DataType.UBYTE -> asmgen.out("${variable.name}\t.byte  ${initialValue.toHex()}")
+            DataType.BYTE -> asmgen.out("${variable.name}\t.char  $initialValue")
+            DataType.UWORD -> asmgen.out("${variable.name}\t.word  ${initialValue.toHex()}")
+            DataType.WORD -> asmgen.out("${variable.name}\t.sint  $initialValue")
+            DataType.FLOAT -> {
+                if(initialValue==0) {
+                    asmgen.out("${variable.name}\t.byte  0,0,0,0,0  ; float")
+                } else {
+                    val floatFill = compTarget.machine.getFloatAsmBytes(initialValue)
+                    asmgen.out("${variable.name}\t.byte  $floatFill  ; float $initialValue")
+                }
+            }
+            DataType.STR -> {
+                throw AssemblyError("all string vars should have been interned into prog")
+            }
+            in ArrayDatatypes -> arrayVariable2asm(variable.name, variable.dt, variable.onetimeInitializationArrayValue, variable.length)
+            else -> {
+                throw AssemblyError("weird dt")
+            }
+        }
+    }
+
+    private fun arrayVariable2asm(varname: String, dt: DataType, value: StArray?, orNumberOfZeros: Int?) {
+        when(dt) {
+            DataType.ARRAY_UB, DataType.ARRAY_BOOL -> {
+                val data = makeArrayFillDataUnsigned(dt, value, orNumberOfZeros)
+                if (data.size <= 16)
+                    asmgen.out("$varname\t.byte  ${data.joinToString()}")
+                else {
+                    asmgen.out(varname)
+                    for (chunk in data.chunked(16))
+                        asmgen.out("  .byte  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_B -> {
+                val data = makeArrayFillDataSigned(dt, value, orNumberOfZeros)
+                if (data.size <= 16)
+                    asmgen.out("$varname\t.char  ${data.joinToString()}")
+                else {
+                    asmgen.out(varname)
+                    for (chunk in data.chunked(16))
+                        asmgen.out("  .char  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_UW -> {
+                val data = makeArrayFillDataUnsigned(dt, value, orNumberOfZeros)
+                if (data.size <= 16)
+                    asmgen.out("$varname\t.word  ${data.joinToString()}")
+                else {
+                    asmgen.out(varname)
+                    for (chunk in data.chunked(16))
+                        asmgen.out("  .word  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_W -> {
+                val data = makeArrayFillDataSigned(dt, value, orNumberOfZeros)
+                if (data.size <= 16)
+                    asmgen.out("$varname\t.sint  ${data.joinToString()}")
+                else {
+                    asmgen.out(varname)
+                    for (chunk in data.chunked(16))
+                        asmgen.out("  .sint  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_UW_SPLIT -> {
+                val data = makeArrayFillDataUnsigned(dt, value, orNumberOfZeros)
+                asmgen.out("_array_$varname := ${data.joinToString()}")
+                asmgen.out("${varname}_lsb\t.byte <_array_$varname")
+                asmgen.out("${varname}_msb\t.byte >_array_$varname")
+            }
+            DataType.ARRAY_W_SPLIT -> {
+                val data = makeArrayFillDataSigned(dt, value, orNumberOfZeros)
+                asmgen.out("_array_$varname := ${data.joinToString()}")
+                asmgen.out("${varname}_lsb\t.byte <_array_$varname")
+                asmgen.out("${varname}_msb\t.byte >_array_$varname")
+            }
+            DataType.ARRAY_F -> {
+                val array = value ?: zeroFilledArray(orNumberOfZeros!!)
+                val floatFills = array.map {
+                    compTarget.machine.getFloatAsmBytes(it.number!!)
+                }
+                asmgen.out(varname)
+                for (f in array.zip(floatFills))
+                    asmgen.out("  .byte  ${f.second}  ; float ${f.first}")
+            }
+            else -> throw AssemblyError("require array dt")
+        }
+    }
+
+    private fun zeroFilledArray(numElts: Int): StArray {
+        val values = mutableListOf<StArrayElement>()
+        repeat(numElts) {
+            values.add(StArrayElement(0.0, null, null))
+        }
+        return values
+    }
+
+    private fun memdefsAndConsts2asm(memvars: Collection<StMemVar>, consts: Collection<StConstant>) {
+        memvars.sortedBy { it.address }.forEach {
+            asmgen.out("  ${it.name} = ${it.address.toHex()}")
+        }
+        consts.sortedBy { it.name }.forEach {
+            if(it.dt==DataType.FLOAT)
+                asmgen.out("  ${it.name} = ${it.value}")
+            else
+                asmgen.out("  ${it.name} = ${it.value.toHex()}")
+        }
+    }
+
+    private fun asmsubs2asm(statements: List<PtNode>) {
+        statements
+            .filter { it is PtAsmSub && it.address!=null }
+            .forEach { asmsub ->
+                asmsub as PtAsmSub
+                asmgen.out("  ${asmsub.name} = ${asmsub.address!!.toHex()}")
+            }
+    }
+
+    private fun outputStringvar(varname: String, encoding: Encoding, value: String) {
+        asmgen.out("$varname\t; $encoding:\"${value.escape().replace("\u0000", "<NULL>")}\"", false)
+        val bytes = compTarget.encodeString(value, encoding).plus(0.toUByte())
+        val outputBytes = bytes.map { "$" + it.toString(16).padStart(2, '0') }
+        for (chunk in outputBytes.chunked(16))
+            asmgen.out("  .byte  " + chunk.joinToString())
+    }
+
+    private fun makeArrayFillDataUnsigned(dt: DataType, value: StArray?, orNumberOfZeros: Int?): List<String> {
+        val array = value ?: zeroFilledArray(orNumberOfZeros!!)
+        return when (dt) {
+            DataType.ARRAY_BOOL ->
+                // byte array can never contain pointer-to types, so treat values as all integers
+                array.map {
+                    if(it.boolean!=null)
+                        if(it.boolean==true) "1" else "0"
+                    else {
+                        val number = it.number!!
+                        if(number==0.0) "0" else "1"
+                    }
+                }
+            DataType.ARRAY_UB ->
+                // byte array can never contain pointer-to types, so treat values as all integers
+                array.map {
+                    val number = it.number!!.toInt()
+                    "$"+number.toString(16).padStart(2, '0')
+                }
+            DataType.ARRAY_UW, DataType.ARRAY_UW_SPLIT -> array.map {
+                if(it.number!=null) {
+                    "$" + it.number!!.toInt().toString(16).padStart(4, '0')
+                }
+                else if(it.addressOfSymbol!=null) {
+                    asmgen.asmSymbolName(it.addressOfSymbol!!)
+                }
+                else
+                    throw AssemblyError("weird array elt")
+            }
+            else -> throw AssemblyError("invalid dt")
+        }
+    }
+
+    private fun makeArrayFillDataSigned(dt: DataType, value: StArray?, orNumberOfZeros: Int?): List<String> {
+        val array = value ?: zeroFilledArray(orNumberOfZeros!!)
+        return when (dt) {
+            // byte array can never contain pointer-to types, so treat values as all integers
+            DataType.ARRAY_UB ->
+                array.map {
+                    val number = it.number!!.toInt()
+                    "$"+number.toString(16).padStart(2, '0')
+                }
+            DataType.ARRAY_B ->
+                array.map {
+                    val number = it.number!!.toInt()
+                    val hexnum = number.absoluteValue.toString(16).padStart(2, '0')
+                    if(number>=0)
+                        "$$hexnum"
+                    else
+                        "-$$hexnum"
+                }
+            DataType.ARRAY_UW, DataType.ARRAY_UW_SPLIT -> array.map {
+                val number = it.number!!.toInt()
+                "$" + number.toString(16).padStart(4, '0')
+            }
+            DataType.ARRAY_W, DataType.ARRAY_W_SPLIT -> array.map {
+                val number = it.number!!.toInt()
+                val hexnum = number.absoluteValue.toString(16).padStart(4, '0')
+                if(number>=0)
+                    "$$hexnum"
+                else
+                    "-$$hexnum"
+            }
+            else -> throw AssemblyError("invalid dt")
+        }
+    }
+
+}

codeGenCpu6502/src/prog8/codegen/cpu6502/VariableAllocator.kt

@@ -0,0 +1,129 @@
+package prog8.codegen.cpu6502
+
+import com.github.michaelbull.result.fold
+import com.github.michaelbull.result.onSuccess
+import prog8.code.StNode
+import prog8.code.StNodeType
+import prog8.code.StStaticVariable
+import prog8.code.SymbolTable
+import prog8.code.core.*
+
+
+internal class VariableAllocator(private val symboltable: SymbolTable,
+                                 private val options: CompilationOptions,
+                                 private val errors: IErrorReporter
+) {
+
+    private val zeropage = options.compTarget.machine.zeropage
+    internal val globalFloatConsts = mutableMapOf<Double, String>()     // all float values in the entire program (value -> varname)
+    internal val zeropageVars: Map<String, MemoryAllocator.VarAllocation>
+
+    init {
+        allocateZeropageVariables()
+        zeropageVars = zeropage.allocatedVariables
+    }
+
+    internal fun isZpVar(scopedName: String) = scopedName in zeropageVars
+
+    internal fun getFloatAsmConst(number: Double): String {
+        val asmName = globalFloatConsts[number]
+        if(asmName!=null)
+            return asmName
+
+        val newName = "prog8_float_const_${globalFloatConsts.size}"
+        globalFloatConsts[number] = newName
+        return newName
+    }
+
+    /**
+     * Allocate variables into the Zeropage.
+     * The result should be retrieved from the current machine's zeropage object!
+     */
+    private fun allocateZeropageVariables() {
+        if(options.zeropage== ZeropageType.DONTUSE)
+            return
+
+        val allVariables = collectAllVariables(symboltable)
+
+        val numberOfAllocatableVariables = allVariables.size
+        val varsRequiringZp = allVariables.filter { it.zpwish == ZeropageWish.REQUIRE_ZEROPAGE }
+        val varsPreferringZp = allVariables.filter { it.zpwish == ZeropageWish.PREFER_ZEROPAGE }
+        val varsNotZp = allVariables.filter { it.zpwish == ZeropageWish.NOT_IN_ZEROPAGE }
+        val varsDontCare = allVariables.filter { it.zpwish == ZeropageWish.DONTCARE }
+        require(varsDontCare.size + varsRequiringZp.size + varsPreferringZp.size + varsNotZp.size == numberOfAllocatableVariables)
+
+        var numVariablesAllocatedInZP = 0
+        var numberOfNonIntegerVariables = 0
+
+        varsRequiringZp.forEach { variable ->
+            val result = zeropage.allocate(
+                variable.scopedName,
+                variable.dt,
+                variable.length,
+                variable.astNode.position,
+                errors
+            )
+            result.fold(
+                success = {
+                    numVariablesAllocatedInZP++
+                },
+                failure = {
+                    errors.err(it.message!!, variable.astNode.position)
+                }
+            )
+        }
+
+        if(errors.noErrors()) {
+            varsPreferringZp.forEach { variable ->
+                val result = zeropage.allocate(
+                    variable.scopedName,
+                    variable.dt,
+                    variable.length,
+                    variable.astNode.position,
+                    errors
+                )
+                result.onSuccess { numVariablesAllocatedInZP++ }
+                //  no need to check for allocation error, if there is one, just allocate in normal system ram.
+            }
+
+            // try to allocate the "don't care" interger variables into the zeropage until it is full.
+            // TODO some form of intelligent priorization? most often used variables first? loopcounter vars first? ...?
+            if(errors.noErrors()) {
+                val sortedList = varsDontCare.sortedByDescending { it.scopedName }
+                for (variable in sortedList) {
+                    if(variable.dt in IntegerDatatypesWithBoolean) {
+                        if(zeropage.free.isEmpty()) {
+                            break
+                        } else {
+                            val result = zeropage.allocate(
+                                variable.scopedName,
+                                variable.dt,
+                                variable.length,
+                                variable.astNode.position,
+                                errors
+                            )
+                            result.onSuccess { numVariablesAllocatedInZP++ }
+                        }
+                    } else
+                        numberOfNonIntegerVariables++
+                }
+            }
+        }
+
+        // note: no zeropage allocation is done at all for the @nozp variables. This means they will always end up outside the zeropage.
+    }
+
+    private fun collectAllVariables(st: SymbolTable): Collection<StStaticVariable> {
+        val vars = mutableListOf<StStaticVariable>()
+        fun collect(node: StNode) {
+            for(child in node.children) {
+                if(child.value.type == StNodeType.STATICVAR)
+                    vars.add(child.value as StStaticVariable)
+                else
+                    collect(child.value)
+            }
+        }
+        collect(st)
+        return vars.sortedBy { it.dt }
+    }
+}

codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/AnyExprAsmGen.kt

@@ -0,0 +1,207 @@
+package prog8.codegen.cpu6502.assignment
+
+import prog8.code.ast.PtBinaryExpression
+import prog8.code.ast.PtExpression
+import prog8.code.core.*
+import prog8.code.target.C64Target
+import prog8.code.target.Cx16Target
+import prog8.codegen.cpu6502.AsmGen6502Internal
+
+//
+// This contains codegen for stack-based evaluation of binary expressions.
+// It uses the CPU stack so depth is limited.
+// It is called "as a last resort" if the optimized codegen path is unable
+// to come up with a special case of the expression.
+//
+internal class AnyExprAsmGen(
+    private val asmgen: AsmGen6502Internal
+) {
+    fun assignAnyExpressionUsingStack(expr: PtBinaryExpression, assign: AsmAssignment): Boolean {
+        when(expr.type) {
+            in ByteDatatypesWithBoolean -> {
+                if(expr.left.type in ByteDatatypesWithBoolean && expr.right.type in ByteDatatypesWithBoolean)
+                    return assignByteBinExpr(expr, assign)
+                if (expr.left.type in WordDatatypes && expr.right.type in WordDatatypes) {
+                    require(expr.operator in ComparisonOperators)
+                    throw AssemblyError("words operands comparison -> byte, should have been handled elsewhere")
+                }
+                if (expr.left.type==DataType.FLOAT && expr.right.type==DataType.FLOAT) {
+                    require(expr.operator in ComparisonOperators)
+                    return assignFloatBinExpr(expr, assign)
+                }
+                throw AssemblyError("weird expr operand types: ${expr.left.type} and ${expr.right.type}")
+            }
+            in WordDatatypes -> {
+                require(expr.left.type in WordDatatypes && expr.right.type in WordDatatypes) {
+                    "both operands must be words"
+                }
+                throw AssemblyError("expression should have been handled otherwise: word ${expr.operator} at ${expr.position}")
+            }
+            DataType.FLOAT -> {
+                require(expr.left.type==DataType.FLOAT && expr.right.type==DataType.FLOAT) {
+                    "both operands must be floats"
+                }
+                return assignFloatBinExpr(expr, assign)
+            }
+            else -> throw AssemblyError("weird expression type in assignment")
+        }
+    }
+
+    private fun assignByteBinExpr(expr: PtBinaryExpression, assign: AsmAssignment): Boolean {
+        when(expr.operator) {
+            "+" -> {
+                asmgen.assignExpressionToRegister(expr.left, RegisterOrPair.A, false)
+                asmgen.out("  pha")
+                asmgen.assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_B1", DataType.UBYTE)
+                asmgen.out("  pla |  clc |  adc  P8ZP_SCRATCH_B1")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "-" -> {
+                asmgen.assignExpressionToRegister(expr.left, RegisterOrPair.A, false)
+                asmgen.out("  pha")
+                asmgen.assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_B1", DataType.UBYTE)
+                asmgen.out("  pla |  sec |  sbc  P8ZP_SCRATCH_B1")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "*" -> TODO("byte * at ${expr.position}")
+            "/" -> TODO("byte / at ${expr.position}")
+            "<<" -> TODO("byte << at ${expr.position}")
+            ">>" -> TODO("byte >> at ${expr.position}")
+            "%" -> TODO("byte % at ${expr.position}")
+            "and" -> TODO("logical and (with optional shortcircuit) ${expr.position}")
+            "or" -> TODO("logical or (with optional shortcircuit) ${expr.position}")
+            "&" -> {
+                asmgen.assignExpressionToRegister(expr.left, RegisterOrPair.A, false)
+                asmgen.out("  pha")
+                asmgen.assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_B1", DataType.UBYTE)
+                asmgen.out("  pla |  and  P8ZP_SCRATCH_B1")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "|" -> {
+                asmgen.assignExpressionToRegister(expr.left, RegisterOrPair.A, false)
+                asmgen.out("  pha")
+                asmgen.assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_B1", DataType.UBYTE)
+                asmgen.out("  pla |  ora  P8ZP_SCRATCH_B1")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "^", "xor" -> {
+                asmgen.assignExpressionToRegister(expr.left, RegisterOrPair.A, false)
+                asmgen.out("  pha")
+                asmgen.assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_B1", DataType.UBYTE)
+                asmgen.out("  pla |  eor  P8ZP_SCRATCH_B1")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "==" -> TODO("byte == at ${expr.position}")
+            "!=" -> TODO("byte != at ${expr.position}")
+            "<" -> TODO("byte < at ${expr.position}")
+            "<=" -> TODO("byte <= at ${expr.position}")
+            ">" -> TODO("byte > at ${expr.position}")
+            ">=" -> TODO("byte >= at ${expr.position}")
+            else -> return false
+        }
+    }
+
+    private fun assignFloatBinExpr(expr: PtBinaryExpression, assign: AsmAssignment): Boolean {
+        when(expr.operator) {
+            "+" -> {
+                assignFloatOperandsToFACandARG(expr.left, expr.right)
+                asmgen.out("  jsr  floats.FADDT")
+                asmgen.assignRegister(RegisterOrPair.FAC1, assign.target)
+                return true
+            }
+            "-" -> {
+                assignFloatOperandsToFACandARG(expr.right, expr.left)
+                asmgen.out("  jsr  floats.FSUBT")
+                asmgen.assignRegister(RegisterOrPair.FAC1, assign.target)
+                return true
+            }
+            "*" -> {
+                assignFloatOperandsToFACandARG(expr.left, expr.right)
+                asmgen.out("  jsr  floats.FMULTT")
+                asmgen.assignRegister(RegisterOrPair.FAC1, assign.target)
+                return true
+            }
+            "/" -> {
+                assignFloatOperandsToFACandARG(expr.right, expr.left)
+                asmgen.out("  jsr  floats.FDIVT")
+                asmgen.assignRegister(RegisterOrPair.FAC1, assign.target)
+                return true
+            }
+            "==" -> {
+                setupFloatComparisonFAC1vsVarAY(expr)
+                asmgen.out("  jsr  floats.var_fac1_equal_f")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "!=" -> {
+                setupFloatComparisonFAC1vsVarAY(expr)
+                asmgen.out("  jsr  floats.var_fac1_notequal_f")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "<" -> {
+                setupFloatComparisonFAC1vsVarAY(expr)
+                asmgen.out("  jsr  floats.var_fac1_less_f")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            ">" -> {
+                setupFloatComparisonFAC1vsVarAY(expr)
+                asmgen.out("  jsr  floats.var_fac1_greater_f")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "<=" -> {
+                setupFloatComparisonFAC1vsVarAY(expr)
+                asmgen.out("  jsr  floats.var_fac1_lesseq_f")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            ">=" -> {
+                setupFloatComparisonFAC1vsVarAY(expr)
+                asmgen.out("  jsr  floats.var_fac1_greatereq_f")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            else -> TODO("float expression operator ${expr.operator}")
+        }
+    }
+
+    private fun assignFloatOperandsToFACandARG(left: PtExpression, right: PtExpression) {
+        when(asmgen.options.compTarget.name) {
+            C64Target.NAME -> {
+                // c64 has a quirk: always make sure FAC2 is loaded last (done using CONUPK)  otherwise the result will be corrupt on C64
+                // this requires some more forced copying around of float values in certain cases
+                if (right.isSimple()) {
+                    asmgen.assignExpressionToRegister(left, RegisterOrPair.FAC1, true)
+                    asmgen.assignExpressionToRegister(right, RegisterOrPair.FAC2, true)
+                } else {
+                    asmgen.assignExpressionToRegister(right, RegisterOrPair.FAC1, true)
+                    asmgen.pushFAC1()
+                    asmgen.assignExpressionToRegister(left, RegisterOrPair.FAC1, true)
+                    asmgen.popFAC2()
+                }
+            }
+            Cx16Target.NAME -> {
+                asmgen.assignExpressionToRegister(left, RegisterOrPair.FAC1, true)
+                if (!right.isSimple()) asmgen.pushFAC1()
+                asmgen.assignExpressionToRegister(right, RegisterOrPair.FAC2, true)
+                if (!right.isSimple()) asmgen.popFAC1()
+            }
+            else -> TODO("don't know how to evaluate float expression for selected compilation target")
+        }
+    }
+
+    private fun setupFloatComparisonFAC1vsVarAY(expr: PtBinaryExpression) {
+        asmgen.assignExpressionToRegister(expr.left, RegisterOrPair.FAC1, true)
+        if(!expr.right.isSimple()) asmgen.pushFAC1()
+        asmgen.assignExpressionToVariable(expr.right, "floats.floats_temp_var", DataType.FLOAT)
+        if(!expr.right.isSimple()) asmgen.popFAC1()
+        asmgen.out("  lda  #<floats.floats_temp_var |  ldy  #>floats.floats_temp_var")
+    }
+}

codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/AsmAssignment.kt

@@ -0,0 +1,240 @@
+package prog8.codegen.cpu6502.assignment
+
+import prog8.code.ast.*
+import prog8.code.core.*
+import prog8.codegen.cpu6502.AsmGen6502Internal
+import prog8.codegen.cpu6502.returnsWhatWhere
+
+
+internal enum class TargetStorageKind {
+    VARIABLE,
+    ARRAY,
+    MEMORY,
+    REGISTER
+}
+
+internal enum class SourceStorageKind {
+    LITERALBOOLEAN,
+    LITERALNUMBER,
+    VARIABLE,
+    ARRAY,
+    MEMORY,
+    REGISTER,
+    EXPRESSION,         // expression in ast-form, still to be evaluated
+}
+
+internal class AsmAssignTarget(val kind: TargetStorageKind,
+                               private val asmgen: AsmGen6502Internal,
+                               val datatype: DataType,
+                               val scope: IPtSubroutine?,
+                               val position: Position,
+                               private val variableAsmName: String? = null,
+                               val array: PtArrayIndexer? = null,
+                               val memory: PtMemoryByte? = null,
+                               val register: RegisterOrPair? = null,
+                               val origAstTarget: PtAssignTarget? = null
+                               )
+{
+    val constArrayIndexValue by lazy { array?.index?.asConstInteger()?.toUInt() }
+    val asmVarname: String by lazy {
+        if (array == null)
+            variableAsmName!!
+        else
+            asmgen.asmVariableName(array.variable)
+    }
+
+    init {
+        if(register!=null && datatype !in NumericDatatypesWithBoolean)
+            throw AssemblyError("must be numeric type")
+    }
+
+    companion object {
+        fun fromAstAssignment(target: PtAssignTarget, definingSub: IPtSubroutine?, asmgen: AsmGen6502Internal): AsmAssignTarget {
+            with(target) {
+                when {
+                    identifier != null -> {
+                        val parameter = asmgen.findSubroutineParameter(identifier!!.name, asmgen)
+                        if (parameter!=null) {
+                            val sub = parameter.definingAsmSub()
+                            if (sub!=null) {
+                                val reg = sub.parameters.single { it.second===parameter }.first
+                                if(reg.statusflag!=null)
+                                    throw AssemblyError("can't assign value to processor statusflag directly")
+                                else
+                                    return AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, type, definingSub, target.position, register=reg.registerOrPair, origAstTarget = this)
+                            }
+                        }
+                        return AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, type, definingSub, target.position, variableAsmName = asmgen.asmVariableName(identifier!!), origAstTarget =  this)
+                    }
+                    array != null -> return AsmAssignTarget(TargetStorageKind.ARRAY, asmgen, type, definingSub, target.position, array = array, origAstTarget =  this)
+                    memory != null -> return AsmAssignTarget(TargetStorageKind.MEMORY, asmgen, type, definingSub, target.position, memory =  memory, origAstTarget =  this)
+                    else -> throw AssemblyError("weird target")
+                }
+            }
+        }
+
+        fun fromRegisters(registers: RegisterOrPair, signed: Boolean, pos: Position, scope: IPtSubroutine?, asmgen: AsmGen6502Internal): AsmAssignTarget =
+                when(registers) {
+                    RegisterOrPair.A,
+                    RegisterOrPair.X,
+                    RegisterOrPair.Y -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, if(signed) DataType.BYTE else DataType.UBYTE, scope, pos, register = registers)
+                    RegisterOrPair.AX,
+                    RegisterOrPair.AY,
+                    RegisterOrPair.XY -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, if(signed) DataType.WORD else DataType.UWORD, scope, pos, register = registers)
+                    RegisterOrPair.FAC1,
+                    RegisterOrPair.FAC2 -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, DataType.FLOAT, scope, pos, register = registers)
+                    RegisterOrPair.R0,
+                    RegisterOrPair.R1,
+                    RegisterOrPair.R2,
+                    RegisterOrPair.R3,
+                    RegisterOrPair.R4,
+                    RegisterOrPair.R5,
+                    RegisterOrPair.R6,
+                    RegisterOrPair.R7,
+                    RegisterOrPair.R8,
+                    RegisterOrPair.R9,
+                    RegisterOrPair.R10,
+                    RegisterOrPair.R11,
+                    RegisterOrPair.R12,
+                    RegisterOrPair.R13,
+                    RegisterOrPair.R14,
+                    RegisterOrPair.R15 -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, if(signed) DataType.WORD else DataType.UWORD, scope, pos, register = registers)
+                }
+    }
+
+    fun isSameAs(left: PtExpression): Boolean =
+        when(kind) {
+            TargetStorageKind.VARIABLE -> {
+                val scopedName: String = if('.' in asmVarname)
+                    asmVarname
+                else {
+                    val scopeName = (scope as? PtNamedNode)?.scopedName
+                    if (scopeName == null) asmVarname else "$scopeName.$asmVarname"
+                }
+                left is PtIdentifier && left.name==scopedName
+            }
+            TargetStorageKind.ARRAY -> {
+                left is PtArrayIndexer && left isSameAs array!! && left.splitWords==array.splitWords
+            }
+            TargetStorageKind.MEMORY -> {
+                left isSameAs memory!!
+            }
+            TargetStorageKind.REGISTER -> {
+                false
+            }
+        }
+}
+
+internal class AsmAssignSource(val kind: SourceStorageKind,
+                               private val program: PtProgram,
+                               private val asmgen: AsmGen6502Internal,
+                               val datatype: DataType,
+                               private val variableAsmName: String? = null,
+                               val array: PtArrayIndexer? = null,
+                               val memory: PtMemoryByte? = null,
+                               val register: RegisterOrPair? = null,
+                               val number: PtNumber? = null,
+                               val boolean: PtBool? = null,
+                               val expression: PtExpression? = null
+)
+{
+    val asmVarname: String
+        get() = if(array==null)
+            variableAsmName!!
+        else
+            asmgen.asmVariableName(array.variable)
+
+    companion object {
+        fun fromAstSource(value: PtExpression, program: PtProgram, asmgen: AsmGen6502Internal): AsmAssignSource {
+            val cv = value as? PtNumber
+            if(cv!=null)
+                return AsmAssignSource(SourceStorageKind.LITERALNUMBER, program, asmgen, cv.type, number = cv)
+            val bv = value as? PtBool
+            if(bv!=null)
+                return AsmAssignSource(SourceStorageKind.LITERALBOOLEAN, program, asmgen, DataType.BOOL, boolean = bv)
+
+            return when(value) {
+                // checked above:   is PtNumber -> throw AssemblyError("should have been constant value")
+                is PtString -> throw AssemblyError("string literal value should not occur anymore for asm generation")
+                is PtArray -> throw AssemblyError("array literal value should not occur anymore for asm generation")
+                is PtIdentifier -> {
+                    val parameter = asmgen.findSubroutineParameter(value.name, asmgen)
+                    if(parameter?.definingAsmSub() != null)
+                        throw AssemblyError("can't assign from a asmsub register parameter $value ${value.position}")
+                    val varName=asmgen.asmVariableName(value)
+                    // special case: "cx16.r[0-15]" are 16-bits virtual registers of the commander X16 system
+                    if(value.type == DataType.UWORD && varName.lowercase().startsWith("cx16.r")) {
+                        val regStr = varName.lowercase().substring(5)
+                        val reg = RegisterOrPair.valueOf(regStr.uppercase())
+                        AsmAssignSource(SourceStorageKind.REGISTER, program, asmgen, value.type, register = reg)
+                    } else {
+                        AsmAssignSource(SourceStorageKind.VARIABLE, program, asmgen, value.type, variableAsmName = varName)
+                    }
+                }
+                is PtMemoryByte -> {
+                    AsmAssignSource(SourceStorageKind.MEMORY, program, asmgen, DataType.UBYTE, memory = value)
+                }
+                is PtArrayIndexer -> {
+                    AsmAssignSource(SourceStorageKind.ARRAY, program, asmgen, value.type, array = value)
+                }
+                is PtBuiltinFunctionCall -> {
+                    AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, value.type, expression = value)
+                }
+                is PtFunctionCall -> {
+                    val symbol = asmgen.symbolTable.lookup(value.name) ?: throw AssemblyError("lookup error ${value.name}")
+                    val sub = symbol.astNode as IPtSubroutine
+                    val returnType = sub.returnsWhatWhere().firstOrNull { rr -> rr.first.registerOrPair != null || rr.first.statusflag!=null }?.second
+                            ?: throw AssemblyError("can't translate zero return values in assignment")
+
+                    AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, returnType, expression = value)
+                }
+                else -> {
+                    AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, value.type, expression = value)
+                }
+            }
+        }
+    }
+
+    fun adjustSignedUnsigned(target: AsmAssignTarget): AsmAssignSource {
+        // allow some signed/unsigned relaxations
+
+        fun withAdjustedDt(newType: DataType) =
+                AsmAssignSource(kind, program, asmgen, newType, variableAsmName, array, memory, register, number, boolean, expression)
+
+        if(target.datatype!=datatype) {
+            if(target.datatype in ByteDatatypes && datatype in ByteDatatypes) {
+                return withAdjustedDt(target.datatype)
+            } else if(target.datatype in WordDatatypes && datatype in WordDatatypes) {
+                return withAdjustedDt(target.datatype)
+            }
+        }
+        return this
+    }
+
+}
+
+
+internal sealed class AsmAssignmentBase(val source: AsmAssignSource,
+                                        val target: AsmAssignTarget,
+                                        val memsizer: IMemSizer,
+                                        val position: Position) {
+    init {
+        if(target.register !in arrayOf(RegisterOrPair.XY, RegisterOrPair.AX, RegisterOrPair.AY))
+            require(source.datatype != DataType.UNDEFINED) { "must not be placeholder/undefined datatype at $position" }
+            require(memsizer.memorySize(source.datatype) <= memsizer.memorySize(target.datatype)) {
+                "source dt size must be less or equal to target dt size at $position srcdt=${source.datatype} targetdt=${target.datatype}"
+            }
+    }
+}
+
+internal class AsmAssignment(source: AsmAssignSource,
+                             target: AsmAssignTarget,
+                             memsizer: IMemSizer,
+                             position: Position): AsmAssignmentBase(source, target, memsizer, position)
+
+internal class AsmAugmentedAssignment(source: AsmAssignSource,
+                                      val operator: String,
+                                      target: AsmAssignTarget,
+                                      memsizer: IMemSizer,
+                                      position: Position): AsmAssignmentBase(source, target, memsizer, position)
+