avoid possible crash

In certain cases you will need to use string.copy() explicitly to overwrite strings with new strings.

.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

@@ -1,5 +1,6 @@
 .idea/workspace.xml
 .idea/discord.xml
+.idea/developer-tools.xml
 build/
 dist/
 output/
@@ -15,6 +16,7 @@ out/
 parser/**/*.interp
 parser/**/*.tokens
 parser/**/*.java
+compiler/src/prog8/buildversion/*
 *.py[cod]
 *.egg
 *.egg-info
@@ -26,6 +28,10 @@ parser.out
 parsetab.py
 .pytest_cache/
 .attach_pid*
+compiler/lib/
 
 .gradle
 /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_4_8_complete.xml

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

.idea/libraries/antlr_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/antlr_runtime_4_8.xml

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

.idea/libraries/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_framework_datatest.xml

@@ -0,0 +1,23 @@
+<component name="libraryTable">
+  <library name="io.kotest.framework.datatest" type="repository">
+    <properties maven-id="io.kotest:kotest-framework-datatest:5.9.1" />
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-datatest/5.9.1/kotest-framework-datatest-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-datatest-jvm/5.9.1/kotest-framework-datatest-jvm-5.9.1.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-core-jvm/1.8.0/kotlinx-coroutines-core-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://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.9.23/kotlin-reflect-1.9.23.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/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-jdk8/1.8.0/kotlinx-coroutines-jdk8-1.8.0.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/kotlinx/kotlinx-coroutines-test-jvm/1.8.0/kotlinx-coroutines-test-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 +1,20 @@
+<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>
+      <root url="jar://$MAVEN_REPOSITORY$/com/michael-bull/kotlin-result/kotlin-result-jvm/2.0.0/kotlin-result-jvm-2.0.0-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.9.22/kotlin-stdlib-1.9.22-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0-javadoc.jar!/" />
+    </JAVADOC>
+    <SOURCES>
+      <root url="jar://$MAVEN_REPOSITORY$/com/michael-bull/kotlin-result/kotlin-result-jvm/2.0.0/kotlin-result-jvm-2.0.0-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.9.22/kotlin-stdlib-1.9.22-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0-sources.jar!/" />
+    </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/misc.xml

@@ -4,7 +4,7 @@
     <option name="perGrammarGenerationSettings">
       <list>
         <PerGrammarGenerationSettings>
-          <option name="fileName" value="$PROJECT_DIR$/parser/antlr/prog8.g4" />
+          <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="" />
@@ -16,7 +16,13 @@
       </list>
     </option>
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="false" project-jdk-name="Kotlin SDK" project-jdk-type="KotlinSDK">
+  <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

@@ -2,10 +2,20 @@
 <project version="4">
   <component name="ProjectModuleManager">
     <modules>
+      <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://$PROJECT_DIR$/benchmark-program/benchmark-program.iml" filepath="$PROJECT_DIR$/benchmark-program/benchmark-program.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>
+</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:
-  - ./gradlew 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"
+

README.md

@@ -1,5 +1,4 @@
-[![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 6502/65c02 microprocessors
@@ -7,37 +6,71 @@ 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 6502/6510/65c02 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).
 
+**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).
+    Note that if you are not using *gradle* to build it, you might have to perform some manual
+    tasks once to make it compile fully. These are explained in the linked instructions. 
+- 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?
 ------------------------
 
-- big reduction of source code length over raw assembly
-- modularity, symbol scoping, subroutines
+- all advantages of a higher level language over having to write assembly code manually
+- programs run very fast because it's compiled 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. No need for forward declarations.
 - 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 an input- and output parameter signature
-- no stack frame allocations because parameters and local variables are automatically allocated statically
-- constant folding in expressions and other high-level program optimizations
-- conditional branches
-- floating point operations  (requires the C64 Basic ROM routines for this)
-- 'when' statement to provide a concise jump table alternative to if/elseif chains
-- many built-in functions such as ``sin``, ``cos``, ``rnd``, ``abs``, ``min``, ``max``, ``sqrt``, ``msb``, ``rol``, ``ror``, ``swap``, ``memset``, ``memcopy``, ``sort`` and ``reverse``
-- structs to group together sets of variables and manipulate them at once
-- convenience abstractions for low level aspects such as ZeroPage handling, program startup, explicit memory addresses
-- fast execution speed due to compilation to native assembly code
+- floating point math is supported on certain targets
+- 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
+- high-level program optimizations
+- programs can be run multiple times without reloading because of automatic variable (re)initializations.
+- conditional branches that map 1:1 to cpu status flags
+- ``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  
 - inline assembly allows you to have full control when every cycle or byte matters
+- supports the sixteen 'virtual' 16-bit registers R0 - R15 from the Commander X16 (also available on other targets)
+- encode strings and characters into petscii or screencodes or even other encodings
 
 *Rapid edit-compile-run-debug cycle:*
 
@@ -46,11 +79,14 @@ What does Prog8 provide?
 - 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
 
-*Two supported compiler targets* (contributions to improve these or to add support for other machines are welcome!):
+*Multiple supported compiler targets* (contributions to improve these or to add support for other machines are welcome!):
 
-- "c64": Commodore-64  (6510 CPU = almost a 6502), the main target.
-- "cx16": [CommanderX16](https://www.commanderx16.com)  (65c02 CPU) .
-- If you only use standard kernel and prog8 library routines, it is possible to compile the *exact same program* for both machines (just change the compiler target flag)!
+- "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)
 
 
 
@@ -67,7 +103,12 @@ IntelliJ IDEA with the Kotlin plugin).
 
 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 the [x16emu emulator](https://github.com/commanderx16/x16-emulator) for the CommanderX16 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
@@ -77,16 +118,13 @@ This code calculates prime numbers using the Sieve of Eratosthenes algorithm::
 
     %import textio
     %zeropage basicsafe
-    
+
     main {
-    
-        ubyte[256] sieve
+        bool[256] sieve
         ubyte candidate_prime = 2       ; is increased in the loop
     
         sub start() {
-            ; clear the sieve, to reset starting situation on subsequent runs
-            memset(sieve, 256, false)   
-            ; calculate primes
+            sys.memset(sieve, 256, 0)   ; clear the sieve
             txt.print("prime numbers up to 255:\n\n")
             ubyte amount=0
             repeat {
@@ -97,17 +135,17 @@ This code calculates prime numbers using the Sieve of Eratosthenes algorithm::
                 txt.print(", ")
                 amount++
             }
-            txt.chrout('\n')
+            txt.nl()
             txt.print("number of primes (expected 54): ")
             txt.print_ub(amount)
-            txt.chrout('\n')
+            txt.nl()
         }
     
         sub find_next_prime() -> ubyte {
             while sieve[candidate_prime] {
                 candidate_prime++
                 if candidate_prime==0
-                    return 0        ; we wrapped; no more primes available in the sieve
+                    return 0        ; we wrapped; no more primes
             }
     
             ; found next one, mark the multiples and return it.
@@ -122,8 +160,6 @@ 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)
@@ -140,7 +176,8 @@ If you want to play a video game, a fully working Tetris clone is included in th
 
 ![tehtriz_screen](docs/source/_static/tehtriz.png)
 
-The CommanderX16 compiler target is quite capable already too, here's a well known space ship 
-animated in 3D with hidden line removal, in the CommanderX16 emulator:
+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)

benchmark-program/Makefile

@@ -0,0 +1,12 @@
+.PHONY:  all clean emu
+
+all:  benchmark.prg
+
+clean:
+	rm -f *.prg *.PRG *.asm *.vice-* *.BIN *.PAL *.zip *.7z
+
+emu:  benchmark.prg
+	x16emu -run -prg $< -warp
+
+benchmark.prg: benchmark.p8 b_3d.p8 b_adpcm.p8 b_circles.p8 b_life.p8 b_mandelbrot.p8 b_maze.p8 b_queens.p8 b_textelite.p8
+	p8compile $< -target cx16 

benchmark-program/b_3d.p8

@@ -0,0 +1,109 @@
+%import textio
+%import math
+
+rotate3d {
+    const ubyte WIDTH = 40
+    const ubyte HEIGHT = 30
+
+    sub benchmark(uword max_time) -> uword {
+
+        uword anglex
+        uword angley
+        uword anglez
+        uword frames
+
+        txt.nl()
+        cbm.SETTIM(0,0,0)
+
+        while cbm.RDTIM16()<max_time {
+            matrix_math.rotate_vertices(msb(anglex), msb(angley), msb(anglez))
+            draw_edges()   ; doesn't really draw anything in the benchmark, but does do the screen calculations
+            anglex+=500
+            angley+=215
+            anglez+=453
+            frames++
+        }
+
+        return frames
+    }
+
+    sub draw_edges() {
+
+        ; plot the points of the 3d cube
+        ; first the points on the back, then the points on the front (painter algorithm)
+
+        ubyte @zp i
+        word @zp rz
+        word @zp persp
+        byte @shared sx
+        byte @shared sy
+
+        for i in 0 to len(matrix_math.xcoor)-1 {
+            rz = matrix_math.rotatedz[i]
+            if rz >= 10 {
+                persp = 600 + rz/64
+                sx = matrix_math.rotatedx[i] / persp as byte + WIDTH/2
+                sy = matrix_math.rotatedy[i] / persp as byte + HEIGHT/2
+                ;; txt.setcc(sx as ubyte, sy as ubyte, 46, 7)
+            }
+        }
+
+        for i in 0 to len(matrix_math.xcoor)-1 {
+            rz = matrix_math.rotatedz[i]
+            if rz < 10 {
+                persp = 600 + rz/64
+                sx = matrix_math.rotatedx[i] / persp as byte + WIDTH/2
+                sy = matrix_math.rotatedy[i] / persp as byte + HEIGHT/2
+                ;; txt.setcc(sx as ubyte, sy as ubyte, 81, 7)
+            }
+        }
+
+        txt.chrout('.')
+    }
+}
+
+matrix_math {
+    ; vertices
+    word[] @split xcoor = [ -40, -40, -40, -40,  40,  40,  40, 40 ]
+    word[] @split ycoor = [ -40, -40,  40,  40, -40, -40,  40, 40 ]
+    word[] @split zcoor = [ -40,  40, -40,  40, -40,  40, -40, 40 ]
+
+    ; storage for rotated coordinates
+    word[len(xcoor)] @split rotatedx
+    word[len(ycoor)] @split rotatedy
+    word[len(zcoor)] @split rotatedz
+
+    sub rotate_vertices(ubyte ax, ubyte ay, ubyte az) {
+        ; rotate around origin (0,0,0)
+
+        ; set up the 3d rotation matrix values
+        word wcosa = math.cos8(ax)
+        word wsina = math.sin8(ax)
+        word wcosb = math.cos8(ay)
+        word wsinb = math.sin8(ay)
+        word wcosc = math.cos8(az)
+        word wsinc = math.sin8(az)
+
+        word wcosa_sinb = wcosa*wsinb / 128
+        word wsina_sinb = wsina*wsinb / 128
+
+        word Axx = wcosa*wcosb / 128
+        word Axy = (wcosa_sinb*wsinc - wsina*wcosc) / 128
+        word Axz = (wcosa_sinb*wcosc + wsina*wsinc) / 128
+        word Ayx = wsina*wcosb / 128
+        word Ayy = (wsina_sinb*wsinc + wcosa*wcosc) / 128
+        word Ayz = (wsina_sinb*wcosc - wcosa*wsinc) / 128
+        word Azx = -wsinb
+        word Azy = wcosb*wsinc / 128
+        word Azz = wcosb*wcosc / 128
+
+        ubyte @zp i
+        for i in 0 to len(xcoor)-1 {
+            ; don't normalize by dividing by 128, instead keep some precision for perspective calc later
+            rotatedx[i] = Axx*xcoor[i] + Axy*ycoor[i] + Axz*zcoor[i]
+            rotatedy[i] = Ayx*xcoor[i] + Ayy*ycoor[i] + Ayz*zcoor[i]
+            rotatedz[i] = Azx*xcoor[i] + Azy*ycoor[i] + Azz*zcoor[i]
+        }
+    }
+
+}

benchmark-program/b_adpcm.p8

@@ -0,0 +1,89 @@
+adpcm {
+
+    sub decode_benchmark(uword max_time) -> uword {
+        uword num_blocks
+        txt.nl()
+        cbm.SETTIM(0,0,0)
+
+        while cbm.RDTIM16()<max_time {
+            adpcm.init(0,0)
+            uword @requirezp nibbles_ptr = $a000 ; for benchmark purposes, the exact nibbles don't really matter, so we just take the basic ROM as input
+            repeat 252/2 {
+                unroll 2 {
+                    ubyte @zp nibble = @(nibbles_ptr)
+                    adpcm.decode_nibble(nibble & 15)     ; first word  (note: upper nibble needs to be zero!)
+                    adpcm.decode_nibble(nibble>>4)       ; second word  (note: upper nibble is zero, after the shifts.)
+                    nibbles_ptr++
+                }
+            }
+            num_blocks++
+            txt.chrout('.')
+        }
+
+        return num_blocks
+    }
+
+    ; IMA ADPCM decoder.  Supports mono and stereo streams.
+
+    ubyte[] t_index = [ -1, -1, -1, -1, 2, 4, 6, 8, -1, -1, -1, -1, 2, 4, 6, 8]
+    uword[] @split t_step = [
+            7, 8, 9, 10, 11, 12, 13, 14,
+            16, 17, 19, 21, 23, 25, 28, 31,
+            34, 37, 41, 45, 50, 55, 60, 66,
+            73, 80, 88, 97, 107, 118, 130, 143,
+            157, 173, 190, 209, 230, 253, 279, 307,
+            337, 371, 408, 449, 494, 544, 598, 658,
+            724, 796, 876, 963, 1060, 1166, 1282, 1411,
+            1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024,
+            3327, 3660, 4026, 4428, 4871, 5358, 5894, 6484,
+            7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
+            15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794,
+            32767]
+
+    uword @requirezp predict       ; decoded 16 bit pcm sample for first channel.
+    ubyte @requirezp index
+    uword @requirezp pstep
+
+    sub init(uword startPredict, ubyte startIndex) {
+        ; initialize first decoding channel.
+        predict = startPredict
+        index = startIndex
+        pstep = t_step[index]
+    }
+
+    sub decode_nibble(ubyte @zp nibble) {
+        ; Decoder for a single nibble for the first channel. (value of 'nibble' needs to be strictly 0-15 !)
+        ; This is the hotspot of the decoder algorithm!
+        ; Note that the generated assembly from this is pretty efficient,
+        ; rewriting it by hand in asm seems to improve it only ~10%.
+        cx16.r0s = 0                ; difference
+        if nibble & %0100 !=0
+            cx16.r0s += pstep
+        pstep >>= 1
+        if nibble & %0010 !=0
+            cx16.r0s += pstep
+        pstep >>= 1
+        if nibble & %0001 !=0
+            cx16.r0s += pstep
+        pstep >>= 1
+        cx16.r0s += pstep
+        if nibble & %1000 !=0
+            predict -= cx16.r0
+        else
+            predict += cx16.r0
+
+        ; NOTE: the original C/Python code uses a 32 bits prediction value and clips it to a 16 bit word
+        ;       but for speed reasons we only work with 16 bit words here all the time (with possible clipping error)
+        ; if predicted > 32767:
+        ;    predicted = 32767
+        ; elif predicted < -32767:
+        ;    predicted = - 32767
+
+        index += t_index[nibble]
+        if_neg
+            index = 0
+        else if index >= len(t_step)-1
+            index = len(t_step)-1
+        pstep = t_step[index]
+    }
+}

benchmark-program/b_circles.p8

@@ -0,0 +1,111 @@
+%import gfx2
+%import math
+
+circles {
+    const ubyte MAX_NUM_CIRCLES = 80
+    const ubyte GROWTH_RATE = 4
+    uword[MAX_NUM_CIRCLES] @split circle_x
+    uword[MAX_NUM_CIRCLES] @split circle_y
+    ubyte[MAX_NUM_CIRCLES] circle_radius
+    ubyte color
+    uword total_num_circles
+
+    sub draw(bool use_kernal, uword max_time) -> uword {
+        if use_kernal
+            void cx16.set_screen_mode(128)
+        else
+            gfx2.screen_mode(1)
+
+        math.rndseed(12345,6789)
+        cbm.SETTIM(0,0,0)
+
+        total_num_circles = 0
+        color = 16
+
+        while cbm.RDTIM16()<max_time {
+            if use_kernal {
+                cx16.GRAPH_set_colors(0,0,0)
+                cx16.GRAPH_clear()
+            }
+            else
+                gfx2.clear_screen(0)
+            total_num_circles += draw_circles(use_kernal, max_time)
+        }
+
+        if use_kernal
+            void cx16.set_screen_mode(3)
+        else {
+            gfx2.screen_mode(0)
+        }
+
+        return total_num_circles
+    }
+
+    sub draw_circles(bool use_kernal, uword max_time) -> uword {
+        uword @zp x
+        uword @zp y
+        ubyte @zp radius
+
+        ubyte num_circles
+
+        while num_circles<MAX_NUM_CIRCLES and cbm.RDTIM16()<max_time {
+            x = math.rndw() % 320
+            y = math.rndw() % 240
+            radius = GROWTH_RATE
+            if not_colliding() {
+                while not_edge() and not_colliding() {
+                    radius += GROWTH_RATE
+                }
+                radius -= GROWTH_RATE
+                if radius>0 {
+                    color++
+                    if color==0
+                        color=16
+                    if use_kernal {
+                        cx16.GRAPH_set_colors(color, 255-color, 0)
+                        cx16.GRAPH_draw_oval(x-radius, y-radius, radius*2, radius*2, true)
+                    }
+                    else
+                        gfx2.disc(x, y as ubyte, radius, color)
+                    circle_x[num_circles] = x
+                    circle_y[num_circles] = y
+                    circle_radius[num_circles] = radius
+                    num_circles++
+                }
+            }
+        }
+
+        return num_circles
+
+        sub not_colliding() -> bool {
+            if num_circles==0
+                return true
+            ubyte @zp c
+            for c in 0 to num_circles-1 {
+                if distance(c) < (radius as uword) + circle_radius[c]
+                    return false
+            }
+            return true
+        }
+
+        sub distance(ubyte cix) -> uword {
+            word dx = x as word - circle_x[cix]
+            word dy = y as word - circle_y[cix]
+            uword sqx = dx*dx as uword
+            uword sqy = dy*dy as uword
+            return sqrt(sqx + sqy)
+        }
+
+        sub not_edge() -> bool {
+            if x as word - radius < 0
+                return false
+            if x + radius >= 320
+                return false
+            if y as word - radius < 0
+                return false
+            if y + radius >= 240
+                return false
+            return true
+        }
+    }
+}

benchmark-program/b_life.p8

@@ -0,0 +1,123 @@
+; conway's game of life.
+
+%import math
+%import textio
+
+life {
+    const ubyte WIDTH = 40
+    const ubyte HEIGHT = 30
+    const uword STRIDE = $0002+WIDTH
+    uword world1 = memory("world1", (WIDTH+2)*(HEIGHT+2), 0)
+    uword world2 = memory("world2", (WIDTH+2)*(HEIGHT+2), 0)
+    uword @requirezp active_world = world1
+
+   sub benchmark(uword max_time) -> uword {
+        txt.clear_screen()
+        sys.memset(world1, (WIDTH+2)*(HEIGHT+2), 0)
+        sys.memset(world2, (WIDTH+2)*(HEIGHT+2), 0)
+
+        set_start_gen()
+
+        uword gen
+        cbm.SETTIM(0,0,0)
+
+        while cbm.RDTIM16()<max_time {
+            next_gen()
+            gen++
+        }
+
+        return gen
+    }
+
+    sub set_start_gen() {
+
+; some way to set a custom start generation:
+;        str start_gen = "                " +
+;                        "                " +
+;                        "                " +
+;                        "          **    " +
+;                        "        *    *  " +
+;                        "       *        " +
+;                        "       *     *  " +
+;                        "       ******   " +
+;                        "                " +
+;                        "                " +
+;                        "                " +
+;                        "                " +
+;                        "                " +
+;                        "                " +
+;                        "                " +
+;                        "               "
+;
+;        for y in 0 to 15 {
+;            for x in 0 to 15 {
+;                if start_gen[y*16 + x]=='*'
+;                    active_world[offset + x] = 1
+;            }
+;            offset += STRIDE
+;        }
+
+        ; randomize whole world
+        math.rndseed(12345,9999)
+        uword offset = STRIDE+1
+        ubyte x
+        ubyte y
+        for y in 0 to HEIGHT-1 {
+            for x in 0 to WIDTH-1 {
+                active_world[offset+x] = math.rnd() & 1
+            }
+            offset += STRIDE
+        }
+    }
+
+    sub next_gen() {
+        const ubyte DXOFFSET = 0
+        const ubyte DYOFFSET = 0
+        ubyte[2] cell_chars = [sc:' ', sc:'●']
+
+        uword @requirezp new_world = world1
+        if active_world == world1
+            new_world = world2
+
+        ; To avoid re-calculating word index lookups into the new- and active world arrays,
+        ; we calculate the required pointer values upfront.
+        ; Inside the loop we can use ptr+x just fine (results in efficient LDA (ptr),Y instruction because x is a byte type),
+        ; and for each row we simply add the stride to the pointer.
+        ; It's more readable to use active_world[offset] etc, but offset is a word value, and this produces
+        ; inefficient assembly code because we can't use a register indexed mode in this case. Costly inside a loop.
+
+        uword @requirezp new_world_ptr = new_world + STRIDE+1-DXOFFSET
+        uword @requirezp active_world_ptr = active_world + STRIDE+1-DXOFFSET
+
+        ubyte x
+        ubyte y
+        for y in DYOFFSET to HEIGHT+DYOFFSET-1 {
+
+            cx16.vaddr_autoincr(1, $b000 + 256*y, 0, 2)     ;  allows us to use simple Vera data byte assigns later instead of setchr() calls
+
+            for x in DXOFFSET to WIDTH+DXOFFSET-1 {
+                ; count the living neighbors
+                ubyte cell = @(active_world_ptr + x)
+                uword @requirezp ptr = active_world_ptr + x - STRIDE - 1
+                ubyte neighbors = @(ptr) + @(ptr+1) + @(ptr+2) +
+                                  @(ptr+STRIDE) + cell + @(ptr+STRIDE+2) +
+                                  @(ptr+STRIDE*2) + @(ptr+STRIDE*2+1) + @(ptr+STRIDE*2+2)
+
+                ; apply game of life rules
+                if neighbors==3
+                    cell=1
+                else if neighbors!=4
+                    cell=0
+                @(new_world_ptr + x) = cell
+
+                ; draw new cell
+                ; txt.setchr(x,y,cell_chars[cell])
+                cx16.VERA_DATA0 = cell_chars[cell]
+            }
+            active_world_ptr += STRIDE
+            new_world_ptr += STRIDE
+        }
+
+        active_world = new_world
+    }
+}

benchmark-program/b_mandelbrot.p8

@@ -0,0 +1,54 @@
+%import textio
+%import floats
+
+mandelbrot {
+    const ubyte width = 39
+    const ubyte height = 29
+    const ubyte max_iter = 15
+
+    sub calc(uword max_time) -> uword  {
+        uword num_pixels
+        ubyte pixelx
+        ubyte pixely
+
+        txt.home()
+        cbm.SETTIM(0,0,0)
+
+        while cbm.RDTIM16() < max_time {
+            for pixely in 0 to height-1 {
+                float yy = (pixely as float)/0.40/height - 1.3
+
+                for pixelx in 0 to width-1 {
+                    float xx = (pixelx as float)/0.32/width - 2.2
+
+                    float xsquared = 0.0
+                    float ysquared = 0.0
+                    float x = 0.0
+                    float y = 0.0
+                    ubyte iter = 0
+
+                    while iter<max_iter and xsquared+ysquared<4.0 {
+                        y = x*y*2.0 + yy
+                        x = xsquared - ysquared + xx
+                        xsquared = x*x
+                        ysquared = y*y
+                        iter++
+                    }
+                    txt.color2(1, max_iter-iter)
+                    txt.spc()
+                    num_pixels++
+
+                    if cbm.RDTIM16()>=max_time
+                        goto finished
+                }
+                txt.nl()
+            }
+
+            txt.clear_screen()
+        }
+
+finished:
+        txt.color2(1, 6)
+        return num_pixels
+    }
+}

benchmark-program/b_maze.p8

@@ -0,0 +1,343 @@
+%import textio
+%import math
+
+; Even though prog8 only has support for extremely limited recursion,
+; you can write recursive algorithms with a bit of extra work by building your own explicit stack structure.
+; This program shows a depth-first maze generation algorithm (1 possible path from start to finish),
+; and a depth-first maze solver algorithm, both using a stack to store the path taken.
+
+; Note: this program can be compiled for multiple target systems.
+
+maze {
+    uword score
+
+    sub bench(uword max_time) -> uword {
+        txt.nl()
+        score=0
+        math.rndseed(2345,44332)
+        cbm.SETTIM(0,0,0)
+        while cbm.RDTIM16()<max_time {
+            maze.initialize()
+            maze.drawStartFinish()
+            if maze.generate(max_time) {
+                maze.openpassages()
+                maze.drawStartFinish()
+                if maze.solve(max_time) {
+                    maze.drawStartFinish()
+                } else break
+            } else break
+        }
+
+        return score
+    }
+
+    const uword screenwidth = 40
+    const uword screenheight = 30
+
+    const ubyte numCellsHoriz = (screenwidth-1) / 2
+    const ubyte numCellsVert = (screenheight-1) / 2
+
+    ; maze start and finish cells
+    const ubyte startCx = 0
+    const ubyte startCy = 0
+    const ubyte finishCx = numCellsHoriz-1
+    const ubyte finishCy = numCellsVert-1
+
+    ; cell properties
+    const ubyte STONE = 128
+    const ubyte WALKED = 64
+    const ubyte BACKTRACKED = 32
+    const ubyte UP = 1
+    const ubyte RIGHT = 2
+    const ubyte DOWN = 4
+    const ubyte LEFT = 8
+    const ubyte WALLCOLOR = 12
+    const ubyte EMPTYCOLOR = 0
+
+    ; unfortunately on larger screens (cx16), the number of cells exceeds 256 and doesn't fit in a regular array anymore.
+    uword cells = memory("cells", numCellsHoriz*numCellsVert, 0)
+
+    ubyte[256] cx_stack
+    ubyte[256] cy_stack
+    ubyte stackptr
+
+    ubyte[4] directionflags = [LEFT,RIGHT,UP,DOWN]
+
+    sub generate(uword max_time) -> bool {
+        ubyte cx = startCx
+        ubyte cy = startCy
+
+        stackptr = 0
+        @(celladdr(cx,cy)) &= ~STONE
+        drawCell(cx, cy)
+        uword cells_to_carve = numCellsHoriz * numCellsVert - 1
+
+        while cbm.RDTIM16()<max_time {
+carve_restart_after_repath:
+            ubyte direction = choose_uncarved_direction()
+            if direction==0 {
+                ;backtrack
+                stackptr--
+                if stackptr==255 {
+                    ; stack empty.
+                    ; repath if we are not done yet. (this is a workaround for the prog8 256 array lenght limit)
+                    if cells_to_carve!=0 {
+                        if repath()
+                            goto carve_restart_after_repath
+                    }
+                    return true
+                }
+                cx = cx_stack[stackptr]
+                cy = cy_stack[stackptr]
+            } else {
+                cx_stack[stackptr] = cx
+                cy_stack[stackptr] = cy
+                stackptr++
+                if stackptr==0 {
+                    ; stack overflow, we can't track our path any longer.
+                    ; repath if we are not done yet. (this is a workaround for the prog8 256 array lenght limit)
+                    if cells_to_carve!=0 {
+                        if repath()
+                            goto carve_restart_after_repath
+                    }
+                    return true
+                }
+                @(celladdr(cx,cy)) |= direction
+                when direction {
+                    UP -> {
+                        cy--
+                        @(celladdr(cx,cy)) |= DOWN
+                    }
+                    RIGHT -> {
+                        cx++
+                        @(celladdr(cx,cy)) |= LEFT
+
+                        score++
+                    }
+                    DOWN -> {
+                        cy++
+                        @(celladdr(cx,cy)) |= UP
+                    }
+                    LEFT -> {
+                        cx--
+                        @(celladdr(cx,cy)) |= RIGHT
+                    }
+                }
+                @(celladdr(cx,cy)) &= ~STONE
+                cells_to_carve--
+                drawCell(cx, cy)
+            }
+        }
+        return false
+
+        sub repath() -> bool {
+            ; repath: try to find a new start cell with possible directions.
+            ; we limit our number of searches so that the algorith doesn't get stuck
+            ; for too long on bad rng... just accept a few unused cells in that case.
+            repeat 255 {
+                do {
+                    cx = math.rnd() % numCellsHoriz
+                    cy = math.rnd() % numCellsVert
+                } until @(celladdr(cx, cy)) & STONE ==0
+                if available_uncarved()!=0
+                    return true
+            }
+            return false
+        }
+
+        sub available_uncarved() -> ubyte {
+            ubyte candidates = 0
+            if cx>0 and @(celladdr(cx-1, cy)) & STONE !=0
+                candidates |= LEFT
+            if cx<numCellsHoriz-1 and @(celladdr(cx+1, cy)) & STONE !=0
+                candidates |= RIGHT
+            if cy>0 and @(celladdr(cx, cy-1)) & STONE !=0
+                candidates |= UP
+            if cy<numCellsVert-1 and @(celladdr(cx, cy+1)) & STONE !=0
+                candidates |= DOWN
+            return candidates
+        }
+
+        sub choose_uncarved_direction() -> ubyte {
+            ubyte candidates =  available_uncarved()
+            if candidates==0
+                return 0
+
+            repeat {
+                ubyte choice = candidates & directionflags[math.rnd() & 3]
+                if choice!=0
+                    return choice
+            }
+        }
+    }
+
+    sub openpassages() {
+        ; open just a few extra passages, so that multiple routes are possible in theory.
+        ubyte numpassages
+        ubyte cx
+        ubyte cy
+        do {
+            do {
+                cx = math.rnd() % (numCellsHoriz-2) + 1
+                cy = math.rnd() % (numCellsVert-2) + 1
+            } until @(celladdr(cx, cy)) & STONE ==0
+            ubyte direction = directionflags[math.rnd() & 3]
+            if @(celladdr(cx, cy)) & direction == 0 {
+                when direction {
+                    LEFT -> {
+                        if @(celladdr(cx-1,cy)) & STONE == 0 {
+                            @(celladdr(cx,cy)) |= LEFT
+                            drawCell(cx,cy)
+                            numpassages++
+                        }
+                    }
+                    RIGHT -> {
+                        if @(celladdr(cx+1,cy)) & STONE == 0 {
+                            @(celladdr(cx,cy)) |= RIGHT
+                            drawCell(cx,cy)
+                            numpassages++
+                        }
+                    }
+                    UP -> {
+                        if @(celladdr(cx,cy-1)) & STONE == 0 {
+                            @(celladdr(cx,cy)) |= UP
+                            drawCell(cx,cy)
+                            numpassages++
+                        }
+                    }
+                    DOWN -> {
+                        if @(celladdr(cx,cy+1)) & STONE == 0 {
+                            @(celladdr(cx,cy)) |= DOWN
+                            drawCell(cx,cy)
+                            numpassages++
+                        }
+                    }
+                }
+            }
+        } until numpassages==10
+    }
+
+    sub solve(uword max_time) -> bool {
+        ubyte cx = startCx
+        ubyte cy = startCy
+        const uword max_path_length = 1024
+
+        ; the path through the maze can be longer than 256 so doesn't fit in a regular array.... :(
+        uword pathstack = memory("pathstack", max_path_length, 0)
+        uword pathstackptr = 0
+
+        @(celladdr(cx,cy)) |= WALKED
+        ; txt.setcc(cx*2+1, cy*2+1, 81, 1)
+
+        while cbm.RDTIM16()<max_time {
+solve_loop:
+            if cx==finishCx and cy==finishCy {
+                ;txt.home()
+                txt.print("found! path length: ")
+                txt.print_uw(pathstackptr)
+                txt.nl()
+                return true
+            }
+
+            ubyte cell = @(celladdr(cx,cy))
+            if cell & UP!=0 and @(celladdr(cx,cy-1)) & (WALKED|BACKTRACKED) ==0 {
+                @(pathstack + pathstackptr) = UP
+                ;txt.setcc(cx*2+1, cy*2, 81, 3)
+                cy--
+            }
+            else if cell & DOWN !=0 and @(celladdr(cx,cy+1)) & (WALKED|BACKTRACKED) ==0 {
+                @(pathstack + pathstackptr) = DOWN
+                ;txt.setcc(cx*2+1, cy*2+2, 81, 3)
+                cy++
+            }
+            else if cell & LEFT !=0 and @(celladdr(cx-1,cy)) & (WALKED|BACKTRACKED) ==0 {
+                @(pathstack + pathstackptr) = LEFT
+                ;txt.setcc(cx*2, cy*2+1, 81, 3)
+                cx--
+            }
+            else if cell & RIGHT !=0 and @(celladdr(cx+1,cy)) & (WALKED|BACKTRACKED) ==0 {
+                @(pathstack + pathstackptr) = RIGHT
+                ;txt.setcc(cx*2+2, cy*2+1, 81, 3)
+                cx++
+            }
+            else {
+                ; dead end, pop stack
+                pathstackptr--
+                if pathstackptr==65535 {
+                    txt.print("no solution?!\n")
+                    return true
+                }
+                @(celladdr(cx,cy)) |= BACKTRACKED
+                ;txt.setcc(cx*2+1, cy*2+1, 81, 2)
+                when @(pathstack + pathstackptr) {
+                    UP -> {
+                        ;txt.setcc(cx*2+1, cy*2+2, 81, 9)
+                        cy++
+                    }
+                    DOWN -> {
+                        ;txt.setcc(cx*2+1, cy*2, 81, 9)
+                        cy--
+                    }
+                    LEFT -> {
+                        ;txt.setcc(cx*2+2, cy*2+1, 81, 9)
+                        cx++
+                    }
+                    RIGHT -> {
+                        ;txt.setcc(cx*2, cy*2+1, 81, 9)
+                        cx--
+
+                        score++
+                    }
+                }
+                goto solve_loop
+            }
+            pathstackptr++
+            if pathstackptr==max_path_length {
+                txt.print("stack overflow, path too long\n")
+                return true
+            }
+            @(celladdr(cx,cy)) |= WALKED
+            ;txt.setcc(cx*2+1, cy*2+1, 81, 1)
+        }
+        return false
+    }
+
+    sub celladdr(ubyte cx, ubyte cy) -> uword {
+        return cells+(numCellsHoriz as uword)*cy+cx
+    }
+
+    sub drawCell(ubyte cx, ubyte cy) {
+        return
+;        ubyte x = cx * 2 + 1
+;        ubyte y = cy * 2 + 1
+;        ubyte doors = @(celladdr(cx,cy))
+;        if doors & UP !=0
+;            txt.setcc(x, y-1, ' ', EMPTYCOLOR)
+;        if doors & RIGHT !=0
+;            txt.setcc(x+1, y, ' ', EMPTYCOLOR)
+;        if doors & DOWN !=0
+;            txt.setcc(x, y+1, ' ', EMPTYCOLOR)
+;        if doors & LEFT !=0
+;            txt.setcc(x-1, y, ' ', EMPTYCOLOR)
+;        if doors & STONE !=0
+;            txt.setcc(x, y, 160, WALLCOLOR)
+;        else
+;            txt.setcc(x, y, 32, EMPTYCOLOR)
+;
+;        if doors & WALKED !=0
+;            txt.setcc(x, y, 81, 1)
+;        if doors & BACKTRACKED !=0
+;            txt.setcc(x, y, 81, 2)
+    }
+
+    sub initialize() {
+        sys.memset(cells, numCellsHoriz*numCellsVert, STONE)
+        ; txt.fill_screen(160, WALLCOLOR)
+        drawStartFinish()
+    }
+
+    sub drawStartFinish() {
+        ; txt.setcc(startCx*2+1,startCy*2+1,sc:'s',5)
+        ; txt.setcc(finishCx*2+1, finishCy*2+1, sc:'f', 13)
+    }
+}

benchmark-program/b_queens.p8

@@ -0,0 +1,63 @@
+%import textio
+
+; Recursive N-Queens solver.
+; The problem is: find all possible ways to place 8 Queen chess pieces on a chess board, so that none of them attacks any other.
+; (this program prints all solutions without taking mirroring and flipping the chess board into account)
+; Note: this program can be compiled for multiple target systems.
+
+queens {
+    const ubyte NUMQUEENS=8
+    ubyte[NUMQUEENS] board
+
+    sub could_place(ubyte row, ubyte col) -> bool {
+        if row==0
+            return true
+        ubyte i
+        for i in 0 to row-1 {
+            if board[i]==col or board[i]-i==col-row or board[i]+i==col+row
+                return false
+        }
+        return true
+    }
+
+    uword solution_count
+    uword maximum_duration
+
+    sub place_queen(ubyte row) -> bool {
+        if row == NUMQUEENS {
+            solution_count++
+            txt.chrout('.')
+            return cbm.RDTIM16()<maximum_duration
+        }
+        bool continue_running=true
+        ubyte col
+        for col in 0 to NUMQUEENS-1 {
+            if could_place(row, col) {
+                board[row] = col
+                ; we need to save the local variables row and col.
+                sys.push(row)
+                sys.push(col)
+                continue_running = place_queen(row + 1)
+                ; restore the local variables after the recursive call.
+                col = sys.pop()
+                row = sys.pop()
+                board[row] = 0
+
+                if not continue_running
+                    break
+            }
+        }
+        return continue_running
+    }
+
+    sub bench(uword max_time) -> uword {
+        solution_count = 0
+        maximum_duration = max_time
+        txt.nl()
+        cbm.SETTIM(0,0,0)
+        while cbm.RDTIM16() < maximum_duration {
+            void place_queen(0)
+        }
+        return solution_count
+    }
+}

benchmark-program/b_textelite.p8

@@ -0,0 +1,990 @@
+%import textio
+%import conv
+%import string
+%import string
+
+
+textelite {
+
+    const ubyte numforLave = 7      ;  Lave is 7th generated planet in galaxy one
+    const ubyte numforZaonce = 129
+    const ubyte numforDiso = 147
+    const ubyte numforRiedquat = 46
+    uword num_commands
+
+    sub bench(uword max_time) -> uword {
+        num_commands = 0
+        txt.lowercase()
+        cbm.SETTIM(0,0,0)
+        while cbm.RDTIM16()<max_time {
+            reinit()
+            run_commands(max_time)
+        }
+        return num_commands
+    }
+
+    sub reinit() {
+        ;txt.clear_screen()
+        ;txt.print("\n --- TextElite v1.3 ---\n")
+        txt.print("\nnew game\n")
+        elite_planet.set_seed(0, 0)
+        elite_galaxy.travel_to(1, numforLave)
+        elite_market.init(0)  ;  Lave's market is seeded with 0
+        elite_ship.init()
+        elite_planet.display(false, 0)
+        input_index = 0
+    }
+
+    sub run_commands(uword max_time) {
+        while cbm.RDTIM16() < max_time {
+            str input = "????????"
+            ;txt.print("\nCash: ")
+            ;elite_util.print_10s(elite_ship.cash)
+            ;txt.print("\nCommand (?=help): ")
+            ubyte num_chars = next_input(input)
+            ;txt.nl()
+            if num_chars!=0 {
+                when input[0] {
+                    'q' -> {
+                        bool has_error = false
+                        if elite_galaxy.number != 2 {
+                            txt.print("\nERROR: galaxy is not 2: ")
+                            txt.print_ub(elite_galaxy.number)
+                            txt.nl()
+                            has_error=true
+                        }
+                        if elite_planet.number != 164 {
+                            txt.print("\nERROR: planet is not 164: ")
+                            txt.print_ub(elite_planet.number)
+                            txt.nl()
+                            has_error=true
+                        }
+                        if elite_planet.x != 116 {
+                            txt.print("\nERROR: planet.x is not 116: ")
+                            txt.print_ub(elite_planet.x)
+                            txt.nl()
+                            has_error=true
+                        }
+                        if elite_planet.y != 201 {
+                            txt.print("\nERROR: planet.y is not 201: ")
+                            txt.print_ub(elite_planet.y)
+                            txt.nl()
+                            has_error=true
+                        }
+                        if "ribeen" != elite_planet.name {
+                            txt.print("\nERROR: planet.name is not 'ribeen': ")
+                            txt.print(elite_planet.name)
+                            txt.nl()
+                            has_error=true
+                        }
+                        if elite_ship.cash != 1212 {
+                            txt.print("\nERROR: cash is not 1212: ")
+                            txt.print_uw(elite_ship.cash)
+                            txt.nl()
+                            has_error=true
+                        }
+                        if elite_ship.fuel != 50 {
+                            txt.print("\nERROR: fuel is not 50:")
+                            txt.print_ub(elite_ship.fuel)
+                            txt.nl()
+                            has_error=true
+                        }
+                        if elite_ship.cargohold[0] != 3 {
+                            txt.print("\nERROR: food is not 3:")
+                            txt.print_ub(elite_ship.cargohold[0])
+                            txt.nl()
+                            has_error=true
+                        }
+                        if elite_ship.cargohold[1] != 0 {
+                            txt.print("\nERROR: textiles is not 0:")
+                            txt.print_ub(elite_ship.cargohold[1])
+                            txt.nl()
+                            has_error=true
+                        }
+                        if has_error
+                            sys.exit(1)
+                        return
+                    }
+                    'b' -> elite_trader.do_buy()
+                    's' -> elite_trader.do_sell()
+                    'f' -> elite_trader.do_fuel()
+                    'j' -> elite_trader.do_jump()
+                    't' -> elite_trader.do_teleport()
+                    'g' -> elite_trader.do_next_galaxy()
+                    'i' -> elite_trader.do_info()
+                    'm' -> {
+                        if input[1]=='a' and input[2]=='p'
+                            elite_trader.do_map()
+                        else
+                            elite_trader.do_show_market()
+                    }
+                    'l' -> elite_trader.do_local()
+                    'c' -> elite_trader.do_cash()
+                    'h' -> elite_trader.do_hold()
+                }
+                num_commands++
+            }
+        }
+    }
+
+    str[] inputs = [
+        "i",
+        "diso",
+        "i",
+        "lave",
+        "m",
+        "b",
+        "food",
+        "15",
+        "map",
+        "g",
+        "map",
+        "l",
+        "j",
+        "zao",
+        "s",
+        "food",
+        "12",
+        "tele",
+        "quti",
+        "tele",
+        "aro",
+        "i",
+        "diso",
+        "i",
+        "lave",
+        "i",
+        "zao",
+        "galhyp",
+        "fuel",
+        "20",
+        "j",
+        "rib",
+        "i",
+        "rib",
+        "i",
+        "tiri",
+        "q",
+        0
+    ]
+
+    ubyte input_index
+
+    sub next_input(str buffer) -> ubyte {
+        input_index++
+        return string.copy(inputs[input_index], buffer)
+    }
+}
+
+elite_trader {
+    str input = "??????????"
+    ubyte num_chars
+
+    sub do_jump() {
+        ;txt.print("\nJump to what system? ")
+        jump_to_system()
+    }
+
+    sub do_teleport() {
+        ;txt.print("\nCheat! Teleport to what system? ")
+        ubyte fuel = elite_ship.fuel
+        elite_ship.fuel = 255
+        jump_to_system()
+        elite_ship.fuel = fuel
+    }
+
+    sub jump_to_system() {
+        void textelite.next_input(input)
+        ubyte current_planet = elite_planet.number
+        ubyte x = elite_planet.x
+        ubyte y = elite_planet.y
+        if elite_galaxy.search_closest_planet(input) {
+            ubyte distance = elite_planet.distance(x, y)
+            if distance <= elite_ship.fuel {
+                elite_galaxy.init_market_for_planet()
+                elite_ship.fuel -= distance
+                ;txt.print("\n\nHyperspace jump! Arrived at:\n")
+                elite_planet.display(true,0 )
+                return
+            }
+            ;txt.print("\nInsufficient fuel\n")
+        } else {
+            ;txt.print(" Not found!\n")
+        }
+        elite_galaxy.travel_to(elite_galaxy.number, current_planet)
+    }
+
+    sub do_buy() {
+        ;txt.print("\nBuy what commodity? ")
+        str commodity = "???????????????"
+        void textelite.next_input(commodity)
+        ubyte ci = elite_market.match(commodity)
+        if ci & 128 !=0 {
+            txt.print("Unknown\n")
+        } else {
+            ;txt.print("\nHow much? ")
+            void textelite.next_input(input)
+            ubyte amount = conv.str2ubyte(input)
+            if elite_market.current_quantity[ci] < amount {
+                txt.print(" Insufficient supply!\n")
+            } else {
+                uword price = elite_market.current_price[ci] * amount
+                ;txt.print(" Total price: ")
+                ;elite_util.print_10s(price)
+                if price > elite_ship.cash {
+                    txt.print(" Not enough cash!\n")
+                } else {
+                    elite_ship.cash -= price
+                    elite_ship.cargohold[ci] += amount
+                    elite_market.current_quantity[ci] -= amount
+                }
+            }
+        }
+    }
+
+    sub do_sell() {
+        ;txt.print("\nSell what commodity? ")
+        str commodity = "???????????????"
+        void textelite.next_input(commodity)
+        ubyte ci = elite_market.match(commodity)
+        if ci & 128 !=0 {
+            txt.print("Unknown\n")
+        } else {
+            ;txt.print("\nHow much? ")
+            void textelite.next_input(input)
+            ubyte amount = conv.str2ubyte(input)
+            if elite_ship.cargohold[ci] < amount {
+                txt.print(" Insufficient supply!\n")
+            } else {
+                uword price = elite_market.current_price[ci] * amount
+                ;txt.print(" Total price: ")
+                ;elite_util.print_10s(price)
+                elite_ship.cash += price
+                elite_ship.cargohold[ci] -= amount
+                elite_market.current_quantity[ci] += amount
+            }
+        }
+    }
+
+    sub do_fuel() {
+        ;txt.print("\nBuy fuel. Amount? ")
+        void textelite.next_input(input)
+        ubyte buy_fuel = 10*conv.str2ubyte(input)
+        ubyte max_fuel = elite_ship.Max_fuel - elite_ship.fuel
+        if buy_fuel > max_fuel
+            buy_fuel = max_fuel
+        uword price = buy_fuel as uword * elite_ship.Fuel_cost
+        if price > elite_ship.cash {
+            txt.print("Not enough cash!\n")
+        } else {
+            elite_ship.cash -= price
+            elite_ship.fuel += buy_fuel
+        }
+    }
+
+    sub do_cash() {
+        ;txt.print("\nCheat! Set cash amount: ")
+        void textelite.next_input(input)
+        elite_ship.cash = conv.str2uword(input)
+    }
+
+    sub do_hold() {
+        ;txt.print("\nCheat! Set cargohold size: ")
+        void textelite.next_input(input)
+        elite_ship.Max_cargo = conv.str2ubyte(input)
+    }
+
+    sub do_next_galaxy() {
+        txt.print("\n>>>>> Galaxy Hyperjump!\n")
+        elite_galaxy.travel_to(elite_galaxy.number+1, elite_planet.number)
+        elite_planet.display(false, 0)
+    }
+
+    sub do_info() {
+        ;txt.print("\nSystem name (empty=current): ")
+        num_chars = textelite.next_input(input)
+        if num_chars!=0 {
+            ubyte current_planet = elite_planet.number
+            ubyte x = elite_planet.x
+            ubyte y = elite_planet.y
+            if elite_galaxy.search_closest_planet(input) {
+                ubyte distance = elite_planet.distance(x, y)
+                elite_planet.display(false, distance)
+            } else {
+                ;txt.print(" Not found!")
+            }
+            elite_galaxy.travel_to(elite_galaxy.number, current_planet)
+        } else {
+            elite_planet.display(false, 0)
+        }
+    }
+
+    sub do_local() {
+        elite_galaxy.local_area()
+    }
+
+    sub do_map() {
+        ;txt.print("\n(l)ocal or (g)alaxy starmap? ")
+        num_chars = textelite.next_input(input)
+        if num_chars!=0 {
+            elite_galaxy.starmap(input[0]=='l')
+        }
+    }
+
+    sub do_show_market() {
+        elite_market.display()
+        ;txt.print("\nFuel: ")
+        ;elite_util.print_10s(elite_ship.fuel)
+        ;txt.print("   Cargohold space: ")
+        ;txt.print_ub(elite_ship.cargo_free())
+        ;txt.print("t\n")
+    }
+}
+
+elite_ship {
+    const ubyte Max_fuel = 70
+    const ubyte Fuel_cost = 2
+    ubyte Max_cargo = 20
+
+    ubyte fuel
+    uword cash
+    ubyte[17] cargohold
+
+    sub init() {
+        sys.memset(cargohold, len(cargohold), 0)
+        fuel = Max_fuel
+        cash = 1000
+    }
+}
+
+elite_market {
+    ubyte[17] baseprices = [$13, $14, $41, $28, $53, $C4, $EB, $9A, $75, $4E, $7C, $B0, $20, $61, $AB, $2D, $35]
+    byte[17] gradients = [-$02, -$01, -$03, -$05, -$05, $08, $1D, $0E, $06, $01, $0d, -$09, -$01, -$01, -$02, -$01, $0F]
+    ubyte[17] basequants = [$06, $0A, $02, $E2, $FB, $36, $08, $38, $28, $11, $1D, $DC, $35, $42, $37, $FA, $C0]
+    ubyte[17] maskbytes = [$01, $03, $07, $1F, $0F, $03, $78, $03, $07, $1F, $07, $3F, $03, $07, $1F, $0F, $07]
+    str[17] names = ["Food", "Textiles", "Radioactives", "Slaves", "Liquor/Wines", "Luxuries", "Narcotics", "Computers",
+                     "Machinery", "Alloys", "Firearms", "Furs", "Minerals", "Gold", "Platinum", "Gem-Stones", "Alien Items"]
+
+    ubyte[17] current_quantity
+    uword[17] current_price
+
+    sub init(ubyte fluct) {
+        ; Prices and availabilities are influenced by the planet's economy type
+        ; (0-7) and a random "fluctuation" byte that was kept within the saved
+        ; commander position to keep the market prices constant over gamesaves.
+        ; Availabilities must be saved with the game since the player alters them
+        ; by buying (and selling(?))
+        ;
+        ; Almost all commands are one byte only and overflow "errors" are
+        ; extremely frequent and exploited.
+        ;
+        ; Trade Item prices are held internally in a single byte=true value/4.
+        ; The decimal point in prices is introduced only when printing them.
+        ; Internally, all prices are integers.
+        ; The player's cash is held in four bytes.
+        ubyte ci
+        for ci in 0 to len(names)-1 {
+            word product
+            byte changing
+            product = elite_planet.economy as word * gradients[ci]
+            changing = fluct & maskbytes[ci]  as byte
+            ubyte q = (basequants[ci] as word + changing - product) as ubyte
+            if q & $80 !=0
+                q = 0  ; clip to positive 8-bit
+            current_quantity[ci] = q & $3f
+            q = (baseprices[ci] + changing + product) as ubyte
+            current_price[ci] = q * $0004
+        }
+        current_quantity[16] = 0        ; force nonavailability of Alien Items
+    }
+
+    sub display() {
+        return
+;        ubyte ci
+;        txt.nl()
+;        elite_planet.print_name_uppercase()
+;        txt.print(" trade market:\n    COMMODITY / PRICE / AVAIL / IN HOLD\n")
+;        for ci in 0 to len(names)-1 {
+;            elite_util.print_right(13, names[ci])
+;            txt.print("   ")
+;            elite_util.print_10s(current_price[ci])
+;            txt.column(24)
+;            txt.print_ub(current_quantity[ci])
+;            txt.chrout(' ')
+;            when units[ci] {
+;                0 -> txt.chrout('t')
+;                1 -> txt.print("kg")
+;                2 -> txt.chrout('g')
+;            }
+;            txt.column(32)
+;            txt.print_ub(elite_ship.cargohold[ci])
+;            txt.nl()
+;        }
+    }
+
+    sub match(uword nameptr) -> ubyte {
+        ubyte ci
+        for ci in 0 to len(names)-1 {
+            if elite_util.prefix_matches(nameptr, names[ci])
+                return ci
+        }
+        return 255
+    }
+}
+
+elite_galaxy {
+    const uword GALSIZE = 256
+    const uword base0 = $5A4A       ; seeds for the first galaxy
+    const uword base1 = $0248
+    const uword base2 = $B753
+
+    str pn_pairs = "..lexegezacebisousesarmaindirea.eratenberalavetiedorquanteisrion"
+
+    ubyte number
+
+    uword[3] seed
+
+    sub init(ubyte galaxynum) {
+        number = 1
+        elite_planet.number = 255
+        seed[0] = base0
+        seed[1] = base1
+        seed[2] = base2
+        repeat galaxynum-1 {
+            nextgalaxy()
+        }
+    }
+
+    sub nextgalaxy() {
+        textelite.num_commands++
+
+        seed[0] = twist(seed[0])
+        seed[1] = twist(seed[1])
+        seed[2] = twist(seed[2])
+        number++
+        if number==9
+            number = 1
+    }
+
+    sub travel_to(ubyte galaxynum, ubyte system) {
+        init(galaxynum)
+        generate_next_planet()   ; always at least planet 0  (separate to avoid repeat ubyte overflow)
+        repeat system {
+            generate_next_planet()
+            textelite.num_commands++
+        }
+        elite_planet.name = make_current_planet_name()
+        init_market_for_planet()
+    }
+
+    sub init_market_for_planet() {
+        elite_market.init(lsb(seed[0])+msb(seed[2]))
+    }
+
+    sub search_closest_planet(uword nameptr) -> bool {
+        textelite.num_commands++
+
+        ubyte x = elite_planet.x
+        ubyte y = elite_planet.y
+        ubyte current_planet_num = elite_planet.number
+
+        init(number)
+        bool found = false
+        ubyte current_closest_pi
+        ubyte current_distance = 127
+        ubyte pi
+        for pi in 0 to 255 {
+            generate_next_planet()
+            elite_planet.name = make_current_planet_name()
+            if elite_util.prefix_matches(nameptr, elite_planet.name) {
+                ubyte distance = elite_planet.distance(x, y)
+                if distance < current_distance {
+                    current_distance = distance
+                    current_closest_pi = pi
+                    found = true
+                }
+            }
+        }
+
+        if found
+            travel_to(number, current_closest_pi)
+        else
+            travel_to(number, current_planet_num)
+
+        return found
+    }
+
+    sub local_area() {
+        ubyte current_planet = elite_planet.number
+        ubyte px = elite_planet.x
+        ubyte py = elite_planet.y
+        ubyte pn = 0
+
+        init(number)
+;        txt.print("\nGalaxy #")
+;        txt.print_ub(number)
+;        txt.print(" - systems in vicinity:\n")
+        do {
+            generate_next_planet()
+            ubyte distance = elite_planet.distance(px, py)
+            if distance <= elite_ship.Max_fuel {
+;                if distance <= elite_ship.fuel
+;                    txt.chrout('*')
+;                else
+;                    txt.chrout('-')
+;                txt.spc()
+                elite_planet.name = make_current_planet_name()
+                elite_planet.display(true, distance)
+            }
+            pn++
+        } until pn==0
+
+        travel_to(number, current_planet)
+    }
+
+    sub starmap(bool local) {
+        ubyte current_planet = elite_planet.number
+        ubyte px = elite_planet.x
+        ubyte py = elite_planet.y
+        str current_name = "        "       ; 8 max
+        ubyte pn = 0
+
+        current_name = elite_planet.name
+        init(number)
+;        txt.clear_screen()
+;        txt.print("Galaxy #")
+;        txt.print_ub(number)
+;        if local
+;            txt.print(" - local systems")
+;        else
+;            txt.print(" - galaxy")
+;        txt.print(" starmap:\n")
+        ubyte max_distance = 255
+        if local
+            max_distance = elite_ship.Max_fuel
+        ubyte home_sx
+        ubyte home_sy
+        ubyte home_distance
+
+        do {
+            generate_next_planet()
+            ubyte distance = elite_planet.distance(px, py)
+            if distance <= max_distance {
+                elite_planet.name = make_current_planet_name()
+                elite_planet.name[0] = string.upperchar(elite_planet.name[0])
+                uword tx = elite_planet.x
+                uword ty = elite_planet.y
+                if local {
+                    tx = tx + 24 - px
+                    ty = ty + 24 - py
+                }
+                ubyte sx = display_scale_x(tx)
+                ubyte sy = display_scale_y(ty)
+                ubyte char = '*'
+                if elite_planet.number==current_planet
+                    char = '%'
+                if local {
+                    print_planet_details(elite_planet.name, sx, sy, distance)
+                } else if elite_planet.number==current_planet {
+                    home_distance = distance
+                    home_sx = sx
+                    home_sy = sy
+                }
+                ; txt.setchr(2+sx, 2+sy, char)
+            }
+            pn++
+        } until pn==0
+
+        if not local
+            print_planet_details(current_name, home_sx, home_sy, home_distance)
+
+;        if local
+;            txt.plot(0, display_scale_y(64) + 4)
+;        else
+;            txt.plot(0, display_scale_y(256) + 4 as ubyte)
+        travel_to(number, current_planet)
+
+        sub print_planet_details(str name, ubyte screenx, ubyte screeny, ubyte d) {
+            return
+;            txt.plot(2+screenx-2, 2+screeny+1)
+;            txt.print(name)
+;            if d!=0 {
+;                txt.plot(2+screenx-2, 2+screeny+2)
+;                elite_util.print_10s(d)
+;                txt.print(" LY")
+;            }
+        }
+
+        sub display_scale_x(uword x) -> ubyte {
+            if local
+                return x/2 as ubyte
+            return x/8 as ubyte
+        }
+
+        sub display_scale_y(uword y) -> ubyte {
+            if local
+                return y/4 as ubyte
+            return y/16 as ubyte
+        }
+    }
+
+    ubyte pn_pair1
+    ubyte pn_pair2
+    ubyte pn_pair3
+    ubyte pn_pair4
+    bool longname
+
+    sub generate_next_planet() {
+        determine_planet_properties()
+        longname = lsb(seed[0]) & 64 !=0
+
+        ; Always four iterations of random number
+        pn_pair1 = (msb(seed[2]) & 31) * 2
+        tweakseed()
+        pn_pair2 = (msb(seed[2]) & 31) * 2
+        tweakseed()
+        pn_pair3 = (msb(seed[2]) & 31) * 2
+        tweakseed()
+        pn_pair4 = (msb(seed[2]) & 31) * 2
+        tweakseed()
+    }
+
+    sub make_current_planet_name() -> str {
+        ubyte ni = 0
+        str name = "         "    ; max 8
+
+        if pn_pairs[pn_pair1] != '.' {
+            name[ni] = pn_pairs[pn_pair1]
+            ni++
+        }
+        if pn_pairs[pn_pair1+1] != '.' {
+            name[ni] = pn_pairs[pn_pair1+1]
+            ni++
+        }
+        if pn_pairs[pn_pair2] != '.' {
+            name[ni] = pn_pairs[pn_pair2]
+            ni++
+        }
+        if pn_pairs[pn_pair2+1] != '.' {
+            name[ni] = pn_pairs[pn_pair2+1]
+            ni++
+        }
+        if pn_pairs[pn_pair3] != '.' {
+            name[ni] = pn_pairs[pn_pair3]
+            ni++
+        }
+        if pn_pairs[pn_pair3+1] != '.' {
+            name[ni] = pn_pairs[pn_pair3+1]
+            ni++
+        }
+
+        if longname {
+            if pn_pairs[pn_pair4] != '.' {
+                name[ni] = pn_pairs[pn_pair4]
+                ni++
+            }
+            if pn_pairs[pn_pair4+1] != '.' {
+                name[ni] = pn_pairs[pn_pair4+1]
+                ni++
+            }
+        }
+
+        name[ni] = 0
+        return name
+    }
+
+    sub determine_planet_properties() {
+        ; create the planet's characteristics
+        elite_planet.number++
+        elite_planet.x = msb(seed[1])
+        elite_planet.y = msb(seed[0])
+        elite_planet.govtype = lsb(seed[1]) >> 3 & 7  ; bits 3,4 &5 of w1
+        elite_planet.economy = msb(seed[0]) & 7  ; bits 8,9 &A of w0
+        if elite_planet.govtype <= 1
+            elite_planet.economy = (elite_planet.economy | 2)
+        elite_planet.techlevel = (msb(seed[1]) & 3) + (elite_planet.economy ^ 7)
+        elite_planet.techlevel += elite_planet.govtype >> 1
+        if elite_planet.govtype & 1 !=0
+            elite_planet.techlevel++
+        elite_planet.population = 4 * elite_planet.techlevel + elite_planet.economy
+        elite_planet.population += elite_planet.govtype + 1
+        elite_planet.productivity = ((elite_planet.economy ^ 7) + 3) * (elite_planet.govtype + 4)
+        elite_planet.productivity *= elite_planet.population * 8
+        ubyte seed2_msb = msb(seed[2])
+        elite_planet.radius = mkword((seed2_msb & 15) + 11, elite_planet.x)
+        elite_planet.species_is_alien = lsb(seed[2]) & 128 !=0      ; bit 7 of w2_lo
+        if elite_planet.species_is_alien {
+            elite_planet.species_size = (seed2_msb >> 2) & 7      ; bits 2-4 of w2_hi
+            elite_planet.species_color = seed2_msb >> 5           ; bits 5-7 of w2_hi
+            elite_planet.species_look = (seed2_msb ^ msb(seed[1])) & 7   ;bits 0-2 of (w0_hi EOR w1_hi)
+            elite_planet.species_kind = (elite_planet.species_look + (seed2_msb & 3)) & 7      ;Add bits 0-1 of w2_hi to A from previous step, and take bits 0-2 of the result
+        }
+
+        elite_planet.goatsoup_seed[0] = lsb(seed[1])
+        elite_planet.goatsoup_seed[1] = msb(seed[1])
+        elite_planet.goatsoup_seed[2] = lsb(seed[2])
+        elite_planet.goatsoup_seed[3] = seed2_msb
+    }
+
+    sub tweakseed() {
+        uword temp = seed[0] + seed[1] + seed[2]
+        seed[0] = seed[1]
+        seed[1] = seed[2]
+        seed[2] = temp
+    }
+
+    sub twist(uword x) -> uword {
+        ubyte xh = msb(x)
+        ubyte xl = lsb(x)
+        xh <<= 1        ; make sure carry flag is not used on first shift!
+        rol(xl)
+        return mkword(xh, xl)
+    }
+}
+
+elite_planet {
+    str[] words81 = ["fabled", "notable", "well known", "famous", "noted"]
+    str[] words82 = ["very", "mildly", "most", "reasonably", ""]
+    str[] words83 = ["ancient", "\x95", "great", "vast", "pink"]
+    str[] words84 = ["\x9E \x9D plantations", "mountains", "\x9C", "\x94 forests", "oceans"]
+    str[] words85 = ["shyness", "silliness", "mating traditions", "loathing of \x86", "love for \x86"]
+    str[] words86 = ["food blenders", "tourists", "poetry", "discos", "\x8E"]
+    str[] words87 = ["talking tree", "crab", "bat", "lobst", "\xB2"]
+    str[] words88 = ["beset", "plagued", "ravaged", "cursed", "scourged"]
+    str[] words89 = ["\x96 civil war", "\x9B \x98 \x99s", "a \x9B disease", "\x96 earthquakes", "\x96 solar activity"]
+    str[] words8A = ["its \x83 \x84", "the \xB1 \x98 \x99", "its inhabitants' \x9A \x85", "\xA1", "its \x8D \x8E"]
+    str[] words8B = ["juice", "brandy", "water", "brew", "gargle blasters"]
+    str[] words8C = ["\xB2", "\xB1 \x99", "\xB1 \xB2", "\xB1 \x9B", "\x9B \xB2"]
+    str[] words8D = ["fabulous", "exotic", "hoopy", "unusual", "exciting"]
+    str[] words8E = ["cuisine", "night life", "casinos", "sit coms", " \xA1 "]
+    str[] words8F = ["\xB0", "The planet \xB0", "The world \xB0", "This planet", "This world"]
+    str[] words90 = ["n unremarkable", " boring", " dull", " tedious", " revolting"]
+    str[] words91 = ["planet", "world", "place", "little planet", "dump"]
+    str[] words92 = ["wasp", "moth", "grub", "ant", "\xB2"]
+    str[] words93 = ["poet", "arts graduate", "yak", "snail", "slug"]
+    str[] words94 = ["tropical", "dense", "rain", "impenetrable", "exuberant"]
+    str[] words95 = ["funny", "wierd", "unusual", "strange", "peculiar"]
+    str[] words96 = ["frequent", "occasional", "unpredictable", "dreadful", "deadly"]
+    str[] words97 = ["\x82 \x81 for \x8A", "\x82 \x81 for \x8A and \x8A", "\x88 by \x89", "\x82 \x81 for \x8A but \x88 by \x89", "a\x90 \x91"]
+    str[] words98 = ["\x9B", "mountain", "edible", "tree", "spotted"]
+    str[] words99 = ["\x9F", "\xA0", "\x87oid", "\x93", "\x92"]
+    str[] words9A = ["ancient", "exceptional", "eccentric", "ingrained", "\x95"]
+    str[] words9B = ["killer", "deadly", "evil", "lethal", "vicious"]
+    str[] words9C = ["parking meters", "dust clouds", "ice bergs", "rock formations", "volcanoes"]
+    str[] words9D = ["plant", "tulip", "banana", "corn", "\xB2weed"]
+    str[] words9E = ["\xB2", "\xB1 \xB2", "\xB1 \x9B", "inhabitant", "\xB1 \xB2"]
+    str[] words9F = ["shrew", "beast", "bison", "snake", "wolf"]
+    str[] wordsA0 = ["leopard", "cat", "monkey", "goat", "fish"]
+    str[] wordsA1 = ["\x8C \x8B", "\xB1 \x9F \xA2", "its \x8D \xA0 \xA2", "\xA3 \xA4", "\x8C \x8B"]
+    str[] wordsA2 = ["meat", "cutlet", "steak", "burgers", "soup"]
+    str[] wordsA3 = ["ice", "mud", "Zero-G", "vacuum", "\xB1 ultra"]
+    str[] wordsA4 = ["hockey", "cricket", "karate", "polo", "tennis"]
+
+    uword[] @shared wordlists = [
+        words81, words82, words83, words84, words85, words86, words87, words88,
+        words89, words8A, words8B, words8C, words8D, words8E, words8F, words90,
+        words91, words92, words93, words94, words95, words96, words97, words98,
+        words99, words9A, words9B, words9C, words9D, words9E, words9F, wordsA0,
+        wordsA1, wordsA2, wordsA3, wordsA4]
+
+    str pairs0 = "abouseitiletstonlonuthnoallexegezacebisousesarmaindirea.eratenbe"
+
+    ubyte[4] goatsoup_rnd = [0, 0, 0, 0]
+    ubyte[4] goatsoup_seed = [0, 0, 0, 0]
+
+    str name = "        "       ; 8 max
+    ubyte number                ; starts at 0 in new galaxy, then increases by 1 for each generated planet
+    ubyte x
+    ubyte y
+    ubyte economy
+    ubyte govtype
+    ubyte techlevel
+    ubyte population
+    uword productivity
+    uword radius
+    bool species_is_alien      ; otherwise "Human Colonials"
+    ubyte species_size
+    ubyte species_color
+    ubyte species_look
+    ubyte species_kind
+
+    sub set_seed(uword s1, uword s2) {
+        goatsoup_seed[0] = lsb(s1)
+        goatsoup_seed[1] = msb(s1)
+        goatsoup_seed[2] = lsb(s2)
+        goatsoup_seed[3] = msb(s2)
+        reset_rnd()
+    }
+
+    sub reset_rnd() {
+        goatsoup_rnd[0] = goatsoup_seed[0]
+        goatsoup_rnd[1] = goatsoup_seed[1]
+        goatsoup_rnd[2] = goatsoup_seed[2]
+        goatsoup_rnd[3] = goatsoup_seed[3]
+    }
+
+    sub random_name() -> str {
+        ubyte ii
+        str randname = "        "       ; 8 chars max
+        ubyte nx = 0
+        for ii in 0 to goatsoup_rnd_number() & 3 {
+            ubyte xx = goatsoup_rnd_number() & $3e
+            if pairs0[xx] != '.' {
+                randname[nx] = pairs0[xx]
+                nx++
+            }
+            xx++
+            if pairs0[xx] != '.' {
+                randname[nx] = pairs0[xx]
+                nx++
+            }
+        }
+        randname[nx] = 0
+        randname[0] = string.upperchar(randname[0])
+        return randname
+    }
+
+    sub goatsoup_rnd_number() -> ubyte {
+        ubyte xx = goatsoup_rnd[0] * 2
+        uword a = xx as uword + goatsoup_rnd[2]
+        if goatsoup_rnd[0] > 127
+            a ++
+        goatsoup_rnd[0] = lsb(a)
+        goatsoup_rnd[2] = xx
+        xx = goatsoup_rnd[1]
+        ubyte ac = xx + goatsoup_rnd[3] + msb(a)
+        goatsoup_rnd[1] = ac
+        goatsoup_rnd[3] = xx
+        return ac
+    }
+
+    sub distance(ubyte px, ubyte py) -> ubyte {
+        uword ax
+        uword ay
+        if px>x
+            ax=px-x
+        else
+            ax=x-px
+        if py>y
+            ay=py-y
+        else
+            ay=y-py
+        ay /= 2
+        ubyte d = sqrt(ax*ax + ay*ay)
+        if d>63
+            return 255
+        return d*4
+    }
+
+    sub soup() -> str {
+        str planet_result = " " * 160
+        uword[6] source_stack
+        ubyte stack_ptr = 0
+        str start_source = "\x8F is \x97."
+        uword source_ptr = &start_source
+        uword result_ptr = &planet_result
+
+        reset_rnd()
+        recursive_soup()
+        return planet_result
+
+        sub recursive_soup() {
+            repeat {
+                ubyte c = @(source_ptr)
+                source_ptr++
+                if c == $00 {
+                    @(result_ptr) = 0
+                    return
+                }
+                else if c <= $80 {
+                    @(result_ptr) = c
+                    result_ptr++
+                }
+                else {
+                    if c <= $a4 {
+                        ubyte rnr = goatsoup_rnd_number()
+                        ubyte wordNr = ((rnr >= $33) as ubyte) + ((rnr >= $66) as ubyte) + ((rnr >= $99) as ubyte) + ((rnr >= $CC) as ubyte)
+                        source_stack[stack_ptr] = source_ptr
+                        stack_ptr++
+                        source_ptr = getword(c, wordNr)
+                        recursive_soup()    ; RECURSIVE CALL - ignore the warning message from the compiler; we don't use local variables or parameters so we're safe in this case
+                        stack_ptr--
+                        source_ptr = source_stack[stack_ptr]
+                    } else {
+                        if c == $b0 {
+                            @(result_ptr) = string.upperchar(name[0])
+                            result_ptr++
+                            concat_string(&name + 1)
+                        }
+                        else if c == $b1 {
+                            @(result_ptr) = string.upperchar(name[0])
+                            result_ptr++
+                            ubyte ni
+                            for ni in 1 to len(name) {
+                                ubyte cc = name[ni]
+                                if cc in ['e', 'o', 0]
+                                    break
+                                else {
+                                    @(result_ptr) = cc
+                                    result_ptr++
+                                }
+                            }
+                            @(result_ptr) = 'i'
+                            result_ptr++
+                            @(result_ptr) = 'a'
+                            result_ptr++
+                            @(result_ptr) = 'n'
+                            result_ptr++
+                        }
+                        else if c == $b2 {
+                            concat_string(random_name())
+                        }
+                        else {
+                            @(result_ptr) = c
+                            result_ptr++
+                        }
+                    }
+                }
+            }
+        }
+
+        sub concat_string(uword str_ptr) {
+            repeat {
+                ubyte c = @(str_ptr)
+                if c==0
+                    break
+                else {
+                    @(result_ptr) = c
+                    str_ptr++
+                    result_ptr++
+                }
+            }
+        }
+    }
+
+    sub display(bool compressed, ubyte distance) {
+        txt.print(soup())
+        txt.nl()
+    }
+
+    sub getword(ubyte listnum, ubyte wordidx) -> uword {
+        uword list = wordlists[listnum-$81]
+        return peekw(list + wordidx*2)
+    }
+}
+
+elite_util {
+    sub prefix_matches(uword prefixptr, uword stringptr) -> bool {
+        repeat {
+            ubyte pc = @(prefixptr)
+            ubyte sc = @(stringptr)
+            if pc == 0
+                return true
+            ; to lowercase for case insensitive compare:
+            if string.lowerchar(pc)!=string.lowerchar(sc)
+                return false
+            prefixptr++
+            stringptr++
+        }
+    }
+}

benchmark-program/benchmark-program.iml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="WEB_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <excludeFolder url="file://$MODULE_DIR$/compiled" />
+    </content>
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

benchmark-program/benchmark.p8

@@ -0,0 +1,112 @@
+
+;  This benchmark program is meant to check for regressions in the
+;  Prog8 compiler's code-generator (performance wise).
+;
+;  As the X16 computer is a more or less fixed system, it's not very useful
+;  to benchmark the computer itself with.
+
+
+%import textio
+%import b_adpcm
+%import b_circles
+%import b_3d
+%import b_life
+%import b_mandelbrot
+%import b_queens
+%import b_textelite
+%import b_maze
+
+%zeropage basicsafe
+%option no_sysinit
+
+
+main {
+
+    str[20] benchmark_names
+    uword[20] benchmark_score
+
+
+    sub start() {
+        ubyte benchmark_number
+
+        void cx16.set_screen_mode(3)
+        txt.color2(1, 6)
+        txt.clear_screen()
+
+        txt.print("\n\n\n  prog8 compiler benchmark tests.\n")
+        sys.wait(60)
+
+        benchmark_number = 0
+
+        announce_benchmark("maze solver")
+        benchmark_score[benchmark_number]  = maze.bench(300)
+        benchmark_number++
+
+        announce_benchmark("n-queens")
+        benchmark_score[benchmark_number]  = queens.bench(300)
+        benchmark_number++
+
+        announce_benchmark("mandelbrot (floating point)")
+        benchmark_score[benchmark_number]  = mandelbrot.calc(400)
+        benchmark_number++
+
+        announce_benchmark("game of life")
+        benchmark_score[benchmark_number]  = life.benchmark(300)
+        benchmark_number++
+
+        announce_benchmark("3d model rotation")
+        benchmark_score[benchmark_number]  = rotate3d.benchmark(300)
+        benchmark_number++
+
+        announce_benchmark("adpcm audio decoding")
+        benchmark_score[benchmark_number]  = adpcm.decode_benchmark(300)
+        benchmark_number++
+
+        announce_benchmark("circles with gfx2")
+        benchmark_score[benchmark_number]  = circles.draw(false, 300)
+        benchmark_number++
+
+;        announce_benchmark("circles with kernal")
+;        benchmark_score[benchmark_number]  = circles.draw(true, 300)
+;        benchmark_number++
+
+        announce_benchmark("text-elite")
+        benchmark_score[benchmark_number]  = textelite.bench(120)
+        benchmark_number++
+
+        benchmark_names[benchmark_number] = 0
+        benchmark_score[benchmark_number] = 0
+
+        void cx16.set_screen_mode(3)
+        txt.uppercase()
+        txt.color2(1, 6)
+        uword final_score
+        benchmark_number = 0
+        txt.print("\nscore benchmark\n\n")
+        do {
+            txt.spc()
+            txt.print_uw(benchmark_score[benchmark_number])
+            txt.column(6)
+            txt.print(benchmark_names[benchmark_number])
+            final_score += benchmark_score[benchmark_number]
+            txt.nl()
+            benchmark_number++
+        } until benchmark_names[benchmark_number]==0
+
+        txt.print("\n\nfinal score : ")
+        txt.print_uw(final_score)
+        txt.nl()
+
+        sub announce_benchmark(str name) {
+            benchmark_names[benchmark_number] = name
+            void cx16.set_screen_mode(3)
+            txt.uppercase()
+            txt.color2(1, 6)
+            txt.clear_screen()
+            txt.plot(4, 6)
+            txt.print(benchmark_names[benchmark_number])
+            txt.nl()
+            sys.wait(60)
+        }
+    }
+}

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 +1,208 @@
+package prog8.code
+
+import prog8.code.ast.*
+import prog8.code.core.*
+import prog8.code.target.VMTarget
+import kotlin.collections.ArrayDeque
+
+
+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 = ArrayDeque<StNode>()
+        scopestack.add(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: ArrayDeque<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.first().add(StMemorySlab("prog8_memoryslab_$slabname", size, align, node))
+                }
+                null
+            }
+            else -> null // node is not present in the ST
+        }
+
+        if(stNode!=null) {
+            scope.last().add(stNode)
+            scope.add(stNode)
+        }
+        node.children.forEach {
+            addToSt(it, scope)
+        }
+        if(stNode!=null)
+            scope.removeLast()
+    }
+
+    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 +1,365 @@
+package prog8.code.ast
+
+import prog8.code.core.*
+import java.util.Objects
+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 -> {
+                if(other !is PtContainmentCheck || other.type != type || !(other.needle isSameAs needle))
+                    false
+                else {
+                    if(haystackHeapVar!=null)
+                        other.haystackHeapVar!=null && other.haystackHeapVar!! isSameAs haystackHeapVar!!
+                    else if(haystackValues!=null)
+                        other.haystackValues!=null && other.haystackValues!! isSameAs haystackValues!!
+                    else
+                        false
+                }
+            }
+            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 $operator"}
+    }
+}
+
+
+class PtContainmentCheck(position: Position): PtExpression(DataType.BOOL, position) {
+    val needle: PtExpression
+        get() = children[0] as PtExpression
+    val haystackHeapVar: PtIdentifier?
+        get() = children[1] as? PtIdentifier
+    val haystackValues: PtArray?
+        get() = children[1] as? PtArray
+
+    companion object {
+        val MAX_SIZE_FOR_INLINE_CHECKS_BYTE = 5
+        val MAX_SIZE_FOR_INLINE_CHECKS_WORD = 4
+    }
+}
+
+
+class PtFunctionCall(val name: String,
+                     val void: Boolean,
+                     type: DataType,
+                     position: Position) : PtExpression(type, position) {
+    val args: List<PtExpression>
+        get() = children.map { it as PtExpression }
+}
+
+
+class PtIdentifier(val name: String, type: DataType, position: Position) : PtExpression(type, position) {
+    override fun toString(): String {
+        return "[PtIdentifier:$name $type $position]"
+    }
+
+    fun copy() = PtIdentifier(name, type, position)
+}
+
+
+class PtMemoryByte(position: Position) : PtExpression(DataType.UBYTE, position) {
+    val address: PtExpression
+        get() = children.single() as PtExpression
+}
+
+
+class PtBool(val value: Boolean, position: Position) : PtExpression(DataType.BOOL, position) {
+    override fun hashCode(): Int = Objects.hash(type, value)
+
+    override fun equals(other: Any?): Boolean {
+        if(other==null || other !is PtBool)
+            return false
+        return value==other.value
+    }
+
+    override fun toString() = "PtBool:$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 -> fromVal .. toVal
+                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 +1,190 @@
+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 -> {
+                val valuelist = node.children.map {
+                    when (it) {
+                        is PtNumber -> it.number.toString()
+                        is PtIdentifier -> it.name
+                        else -> "?"
+                    }
+                }.joinToString(", ")
+                "array len=${node.children.size} ${type(node.type)} [ $valuelist ]"
+            }
+            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 +1,181 @@
+package prog8.code.ast
+
+import prog8.code.core.*
+
+
+sealed interface IPtSubroutine {
+    val name: String
+    val scopedName: 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 +1,139 @@
+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),
+    "callfar2"  to FSignature(false, listOf(FParam("bank", arrayOf(DataType.UBYTE)), FParam("address", arrayOf(DataType.UWORD)), FParam("argA", arrayOf(DataType.UBYTE)), FParam("argX", arrayOf(DataType.UBYTE)), FParam("argY", arrayOf(DataType.UBYTE)), FParam("argC", arrayOf(DataType.BOOL))), 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 +1,41 @@
+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 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 +1,145 @@
+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() &&
+            (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 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
+}

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 +1,63 @@
+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 'io.kotest:kotest-framework-datatest: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 +1,19 @@
+<?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" />
+    <orderEntry type="library" name="io.kotest.framework.datatest" level="project" />
+  </component>
+</module>

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

@@ -0,0 +1,749 @@
+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(!haslabel(second)) {
+            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 ((" 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")
+    }
+}