version 8.0

was caused by a change in 7.8; 8ae3bad6f7 "fix rts in empty asmsub"

.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

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="CompilerConfiguration">
-    <option name="BUILD_PROCESS_HEAP_SIZE" value="1200" />
+    <option name="BUILD_PROCESS_HEAP_SIZE" value="3000" />
     <bytecodeTargetLevel target="11" />
   </component>
-</project>
+</project>

.idea/inspectionProfiles/Project_Default.xml

@@ -7,6 +7,7 @@
         <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="SpellCheckingInspection" enabled="true" level="TYPO" enabled_by_default="true">
       <option name="processCode" value="false" />

.idea/libraries/antlr_antlr4.xml

@@ -1,15 +1,15 @@
 <component name="libraryTable">
   <library name="antlr.antlr4" type="repository">
-    <properties maven-id="org.antlr:antlr4:4.9.2">
+    <properties maven-id="org.antlr:antlr4:4.9.3">
       <exclude>
         <dependency maven-id="com.ibm.icu:icu4j" />
       </exclude>
     </properties>
     <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4/4.9.2/antlr4-4.9.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4-runtime/4.9.2/antlr4-runtime-4.9.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4/4.9.3/antlr4-4.9.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4-runtime/4.9.3/antlr4-runtime-4.9.3.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr-runtime/3.5.2/antlr-runtime-3.5.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/ST4/4.3/ST4-4.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/ST4/4.3.1/ST4-4.3.1.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/org/abego/treelayout/org.abego.treelayout.core/1.0.3/org.abego.treelayout.core-1.0.3.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/org/glassfish/javax.json/1.0.4/javax.json-1.0.4.jar!/" />
     </CLASSES>

.idea/libraries/hamcrest.xml

@@ -1,10 +0,0 @@
-<component name="libraryTable">
-  <library name="hamcrest" type="repository">
-    <properties maven-id="org.hamcrest:hamcrest:2.2" />
-    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/hamcrest/hamcrest/2.2/hamcrest-2.2.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>

.idea/libraries/io_kotest_assertions_core_jvm.xml

@@ -0,0 +1,23 @@
+<component name="libraryTable">
+  <library name="io.kotest.assertions.core.jvm" type="repository">
+    <properties maven-id="io.kotest:kotest-assertions-core-jvm:5.1.0" />
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.1.0/kotest-assertions-core-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.6.10/kotlin-stdlib-jdk8-1.6.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.6.10/kotlin-stdlib-1.6.10.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-jdk7/1.6.10/kotlin-stdlib-jdk7-1.6.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.1.0/kotest-assertions-shared-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/github/java-diff-utils/java-diff-utils/4.11/java-diff-utils-4.11.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.6.0/kotlinx-coroutines-jdk8-1.6.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.6.10/kotlin-reflect-1.6.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.0/kotlinx-coroutines-core-jvm-1.6.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.6.0/kotlin-stdlib-common-1.6.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.1.0/kotest-common-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.1.0/kotest-assertions-api-jvm-5.1.0.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>

.idea/libraries/io_kotest_property_jvm.xml

@@ -0,0 +1,24 @@
+<component name="libraryTable">
+  <library name="io.kotest.property.jvm" type="repository">
+    <properties maven-id="io.kotest:kotest-property-jvm:5.1.0" />
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-property-jvm/5.1.0/kotest-property-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.1.0/kotest-common-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.1.0/kotest-assertions-shared-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.1.0/kotest-assertions-api-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.6.0/kotlinx-coroutines-jdk8-1.6.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.6.10/kotlin-stdlib-jdk8-1.6.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.6.10/kotlin-stdlib-1.6.10.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-jdk7/1.6.10/kotlin-stdlib-jdk7-1.6.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.6.10/kotlin-reflect-1.6.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.0/kotlinx-coroutines-core-jvm-1.6.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.6.0/kotlin-stdlib-common-1.6.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/github/java-diff-utils/java-diff-utils/4.11/java-diff-utils-4.11.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/com/github/curious-odd-man/rgxgen/1.3/rgxgen-1.3.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>

.idea/libraries/io_kotest_runner_junit5_jvm.xml

@@ -0,0 +1,53 @@
+<component name="libraryTable">
+  <library name="io.kotest.runner.junit5.jvm" type="repository">
+    <properties maven-id="io.kotest:kotest-runner-junit5-jvm:5.1.0" />
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-runner-junit5-jvm/5.1.0/kotest-runner-junit5-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-api-jvm/5.1.0/kotest-framework-api-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-test-jvm/1.6.0/kotlinx-coroutines-test-jvm-1.6.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.1.0/kotest-assertions-shared-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/github/java-diff-utils/java-diff-utils/4.11/java-diff-utils-4.11.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.1.0/kotest-common-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-engine-jvm/5.1.0/kotest-framework-engine-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/github/classgraph/classgraph/4.8.138/classgraph-4.8.138.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/jetbrains/kotlinx/kotlinx-coroutines-debug/1.6.0/kotlinx-coroutines-debug-1.6.0.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://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-discovery-jvm/5.1.0/kotest-framework-discovery-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.1.0/kotest-assertions-core-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.6.0/kotlinx-coroutines-jdk8-1.6.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.1.0/kotest-assertions-api-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-extensions-jvm/5.1.0/kotest-extensions-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/commons-io/commons-io/2.11.0/commons-io-2.11.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk/1.12.2/mockk-1.12.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-dsl-jvm/1.12.2/mockk-dsl-jvm-1.12.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-dsl/1.12.2/mockk-dsl-1.12.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-common/1.12.2/mockk-common-1.12.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-agent-jvm/1.12.2/mockk-agent-jvm-1.12.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-agent-api/1.12.2/mockk-agent-api-1.12.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-agent-common/1.12.2/mockk-agent-common-1.12.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/objenesis/objenesis/3.1/objenesis-3.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/net/bytebuddy/byte-buddy/1.12.5/byte-buddy-1.12.5.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/net/bytebuddy/byte-buddy-agent/1.12.5/byte-buddy-agent-1.12.5.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-concurrency-jvm/5.1.0/kotest-framework-concurrency-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.0/kotlinx-coroutines-core-jvm-1.6.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.6.0/kotlin-stdlib-common-1.6.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-engine/1.7.2/junit-platform-engine-1.7.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/apiguardian/apiguardian-api/1.1.0/apiguardian-api-1.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-commons/1.7.2/junit-platform-commons-1.7.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-suite-api/1.7.2/junit-platform-suite-api-1.7.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-launcher/1.7.2/junit-platform-launcher-1.7.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-api/5.7.2/junit-jupiter-api-5.7.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.6.10/kotlin-stdlib-jdk8-1.6.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.6.10/kotlin-stdlib-1.6.10.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-jdk7/1.6.10/kotlin-stdlib-jdk7-1.6.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.6.10/kotlin-reflect-1.6.10.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>

.idea/libraries/jetbrains_kotlinx_cli_jvm.xml

@@ -1,8 +1,8 @@
 <component name="libraryTable">
   <library name="jetbrains.kotlinx.cli.jvm" type="repository">
-    <properties include-transitive-deps="false" maven-id="org.jetbrains.kotlinx:kotlinx-cli-jvm:0.3.3" />
+    <properties include-transitive-deps="false" maven-id="org.jetbrains.kotlinx:kotlinx-cli-jvm:0.3.4" />
     <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-cli-jvm/0.3.3/kotlinx-cli-jvm-0.3.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-cli-jvm/0.3.4/kotlinx-cli-jvm-0.3.4.jar!/" />
     </CLASSES>
     <JAVADOC />
     <SOURCES />

.idea/libraries/junit_jupiter.xml

@@ -1,17 +0,0 @@
-<component name="libraryTable">
-  <library name="junit.jupiter" type="repository">
-    <properties maven-id="org.junit.jupiter:junit-jupiter:5.7.2" />
-    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter/5.7.2/junit-jupiter-5.7.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-api/5.7.2/junit-jupiter-api-5.7.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/apiguardian/apiguardian-api/1.1.0/apiguardian-api-1.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-commons/1.7.2/junit-platform-commons-1.7.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-params/5.7.2/junit-jupiter-params-5.7.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-engine/5.7.2/junit-jupiter-engine-5.7.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-engine/1.7.2/junit-platform-engine-1.7.2.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>

.idea/libraries/michael_bull_kotlin_result_jvm.xml

@@ -1,13 +1,13 @@
 <component name="libraryTable">
   <library name="michael.bull.kotlin.result.jvm" type="repository">
-    <properties maven-id="com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.12" />
+    <properties maven-id="com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.14" />
     <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/com/michael-bull/kotlin-result/kotlin-result-jvm/1.1.12/kotlin-result-jvm-1.1.12.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.5.10/kotlin-stdlib-jdk8-1.5.10.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.5.10/kotlin-stdlib-1.5.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/com/michael-bull/kotlin-result/kotlin-result-jvm/1.1.14/kotlin-result-jvm-1.1.14.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.6.10/kotlin-stdlib-jdk8-1.6.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.6.10/kotlin-stdlib-1.6.10.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-jdk7/1.5.10/kotlin-stdlib-jdk7-1.5.10.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.5.10/kotlin-stdlib-common-1.5.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.6.10/kotlin-stdlib-jdk7-1.6.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.6.10/kotlin-stdlib-common-1.6.10.jar!/" />
     </CLASSES>
     <JAVADOC />
     <SOURCES />

.idea/libraries/slf4j_simple.xml

@@ -1,9 +1,9 @@
 <component name="libraryTable">
   <library name="slf4j.simple" type="repository">
-    <properties maven-id="org.slf4j:slf4j-simple:1.7.30" />
+    <properties maven-id="org.slf4j:slf4j-simple:1.7.36" />
     <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/slf4j/slf4j-simple/1.7.30/slf4j-simple-1.7.30.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/slf4j/slf4j-api/1.7.30/slf4j-api-1.7.30.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/slf4j/slf4j-simple/1.7.36/slf4j-simple-1.7.36.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/slf4j/slf4j-api/1.7.36/slf4j-api-1.7.36.jar!/" />
     </CLASSES>
     <JAVADOC />
     <SOURCES />

.idea/misc.xml

@@ -16,7 +16,10 @@
       </list>
     </option>
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" project-jdk-name="Kotlin SDK" project-jdk-type="KotlinSDK">
+  <component name="FrameworkDetectionExcludesConfiguration">
+    <type id="Python" />
+  </component>
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" project-jdk-name="11" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
-</project>
+</project>

.idea/modules.xml

@@ -2,16 +2,20 @@
 <project version="4">
   <component name="ProjectModuleManager">
     <modules>
-      <module fileurl="file://$PROJECT_DIR$/codeGeneration/codeGeneration.iml" filepath="$PROJECT_DIR$/codeGeneration/codeGeneration.iml" />
+      <module fileurl="file://$PROJECT_DIR$/codeAst/codeAst.iml" filepath="$PROJECT_DIR$/codeAst/codeAst.iml" />
+      <module fileurl="file://$PROJECT_DIR$/codeCore/codeCore.iml" filepath="$PROJECT_DIR$/codeCore/codeCore.iml" />
+      <module fileurl="file://$PROJECT_DIR$/codeGenCpu6502/codeGenCpu6502.iml" filepath="$PROJECT_DIR$/codeGenCpu6502/codeGenCpu6502.iml" />
+      <module fileurl="file://$PROJECT_DIR$/codeGenExperimental/codeGenExperimental.iml" filepath="$PROJECT_DIR$/codeGenExperimental/codeGenExperimental.iml" />
+      <module fileurl="file://$PROJECT_DIR$/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://$PROJECT_DIR$/compilerInterfaces/compilerInterfaces.iml" filepath="$PROJECT_DIR$/compilerInterfaces/compilerInterfaces.iml" />
       <module fileurl="file://$PROJECT_DIR$/dbusCompilerService/dbusCompilerService.iml" filepath="$PROJECT_DIR$/dbusCompilerService/dbusCompilerService.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://$PROJECT_DIR$/httpCompilerService/httpCompilerService.iml" filepath="$PROJECT_DIR$/httpCompilerService/httpCompilerService.iml" />
       <module fileurl="file://$PROJECT_DIR$/parser/parser.iml" filepath="$PROJECT_DIR$/parser/parser.iml" />
+      <module fileurl="file://$PROJECT_DIR$/virtualmachine/virtualmachine.iml" filepath="$PROJECT_DIR$/virtualmachine/virtualmachine.iml" />
     </modules>
   </component>
 </project>

.idea/vcs.xml

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

CompilerDevelopment.md

@@ -12,6 +12,9 @@
 * The same argument applies to `IMemSizer`, and - not entirely sure about that - `IBuiltinFunctions`.
 
 #### Steps to take, in conceptual (!) order:
+
+(note: all these steps have been implemented, rejected or otherwise solved now.)
+
 1. introduce an abstraction `SourceCode` that encapsulates the origin and actual loading of Prog8 source code
    - from the local file system (use case: user programs)
    - from resources (prog8lib)

README.md

@@ -37,7 +37,8 @@ What does Prog8 provide?
 - small program boilerplate/compilersupport overhead
 - programs can be run multiple times without reloading because of automatic variable (re)initializations.
 - conditional branches
-- 'when' statement to provide a concise jump table alternative to if/elseif chains
+- ``when`` statement to provide a concise jump table alternative to if/elseif chains
+- ``in`` expression for concise and efficient multi-value/containment check 
 - many built-in functions such as ``sin``, ``cos``, ``rnd``, ``abs``, ``min``, ``max``, ``sqrt``, ``msb``, ``rol``, ``ror``, ``swap``, ``sort`` and ``reverse``
 - various powerful built-in libraries to do I/O, number conversions, graphics and more  
 - convenience abstractions for low level aspects such as ZeroPage handling, program startup, explicit memory addresses
@@ -52,11 +53,12 @@ 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)
+- "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)
-- If you only use standard kernal and prog8 library routines, it is possible to compile the *exact same program* for both machines (just change the compiler target flag)!
+- 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)
 
 
 

codeAst/build.gradle

@@ -0,0 +1,42 @@
+
+plugins {
+    id 'java'
+    id 'application'
+    id "org.jetbrains.kotlin.jvm"
+}
+
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(javaVersion)
+    }
+}
+
+compileKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+compileTestKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+dependencies {
+    implementation project(':codeCore')
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
+}
+
+sourceSets {
+    main {
+        java {
+            srcDirs = ["${project.projectDir}/src"]
+        }
+        resources {
+            srcDirs = ["${project.projectDir}/res"]
+        }
+    }
+}
+
+// note: there are no unit tests in this module!

codeAst/codeAst.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="module" module-name="codeCore" />
+  </component>
+</module>

codeAst/src/prog8/code/SymbolTable.kt

@@ -0,0 +1,217 @@
+package prog8.code
+
+import prog8.code.core.*
+
+
+/**
+ * Tree structure containing all symbol definitions in the program
+ * (blocks, subroutines, variables (all types) and labels).
+ */
+class SymbolTable : StNode("", StNodeType.GLOBAL, Position.DUMMY) {
+    fun print() = printIndented(0)
+
+    override fun printProperties() { }
+
+    /**
+     * The table as a flat mapping of scoped names to the StNode.
+     * This gives the fastest lookup possible (no need to traverse tree nodes)
+     */
+    val flat: Map<List<String>, StNode> by lazy {
+        val result = mutableMapOf<List<String>, StNode>()
+        fun flatten(node: StNode) {
+            result[node.scopedName] = node
+            node.children.values.forEach { flatten(it) }
+        }
+        children.values.forEach { flatten(it) }
+        result
+    }
+
+    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
+    }
+
+    override fun lookup(scopedName: List<String>) = flat[scopedName]
+}
+
+
+enum class StNodeType {
+    GLOBAL,
+    // MODULE,     // not used with current scoping rules
+    BLOCK,
+    SUBROUTINE,
+    ROMSUB,
+    LABEL,
+    STATICVAR,
+    MEMVAR,
+    CONSTANT,
+    BUILTINFUNC
+}
+
+
+open class StNode(val name: String,
+                  val type: StNodeType,
+                  val position: Position,
+                  val children: MutableMap<String, StNode> = mutableMapOf()
+) {
+
+    lateinit var parent: StNode
+
+    val scopedName: List<String> by lazy {
+        if(type== StNodeType.GLOBAL)
+            emptyList()
+        else
+            parent.scopedName + name
+    }
+
+    fun lookup(name: String) =
+        lookupUnqualified(name)
+    open fun lookup(scopedName: List<String>) =
+        if(scopedName.size>1) lookupQualified(scopedName) else lookupUnqualified(scopedName[0])
+    fun lookupOrElse(name: String, default: () -> StNode) =
+        lookupUnqualified(name) ?: default()
+    fun lookupOrElse(scopedName: List<String>, default: () -> StNode) =
+        lookup(scopedName) ?: default()
+
+    private fun lookupQualified(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
+    }
+
+    private fun lookupUnqualified(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 printIndented(indent: Int) {
+        print("    ".repeat(indent))
+        when(type) {
+            StNodeType.GLOBAL -> print("SYMBOL-TABLE:")
+            StNodeType.BLOCK -> print("(B) ")
+            StNodeType.SUBROUTINE -> print("(S) ")
+            StNodeType.LABEL -> print("(L) ")
+            StNodeType.STATICVAR -> print("(V) ")
+            StNodeType.MEMVAR -> print("(M) ")
+            StNodeType.CONSTANT -> print("(C) ")
+            StNodeType.BUILTINFUNC -> print("(F) ")
+            StNodeType.ROMSUB -> print("(R) ")
+        }
+        printProperties()
+        println()
+        children.forEach { (_, node) -> node.printIndented(indent+1) }
+    }
+
+    open fun printProperties() {
+        print("$name  ")
+    }
+
+    fun add(child: StNode) {
+        children[child.name] = child
+        child.parent = this
+    }
+}
+
+class StStaticVariable(name: String,
+                       val dt: DataType,
+                       val initialNumericValue: Double?,
+                       val initialStringValue: StString?,
+                       val initialArrayValue: StArray?,
+                       val length: Int?,             // for arrays: the number of elements, for strings: number of characters *including* the terminating 0-byte
+                       val zpwish: ZeropageWish,
+                       position: Position) : StNode(name, StNodeType.STATICVAR, position) {
+
+    init {
+        if(length!=null) {
+            require(initialNumericValue == null)
+            if(initialArrayValue!=null)
+                require(length == initialArrayValue.size)
+        }
+        if(initialNumericValue!=null)
+            require(dt in NumericDatatypes)
+        if(initialArrayValue!=null)
+            require(dt in ArrayDatatypes)
+        if(initialStringValue!=null) {
+            require(dt == DataType.STR)
+            require(length == initialStringValue.first.length+1)
+        }
+    }
+
+    override fun printProperties() {
+        print("$name  dt=$dt  zpw=$zpwish")
+    }
+}
+
+
+class StConstant(name: String, val dt: DataType, val value: Double, position: Position) :
+    StNode(name, StNodeType.CONSTANT, position) {
+    override fun printProperties() {
+        print("$name  dt=$dt value=$value")
+    }
+}
+
+
+class StMemVar(name: String, val dt: DataType, val address: UInt, position: Position) :
+    StNode(name, StNodeType.MEMVAR, position) {
+    override fun printProperties() {
+        print("$name  dt=$dt address=${address.toHex()}")
+    }
+}
+
+
+class StSub(name: String, val parameters: List<StSubroutineParameter>, position: Position) :
+        StNode(name, StNodeType.SUBROUTINE, position) {
+    override fun printProperties() {
+        print(name)
+    }
+}
+
+
+class StRomSub(name: String, val address: UInt, parameters: List<StSubroutineParameter>, position: Position) :
+    StNode(name, StNodeType.ROMSUB, position) {
+    override fun printProperties() {
+        print("$name  address=${address.toHex()}")
+    }
+}
+
+
+class StSubroutineParameter(val name: String, val type: DataType)
+class StArrayElement(val number: Double?, val addressOf: List<String>?)
+
+typealias StString = Pair<String, Encoding>
+typealias StArray = List<StArrayElement>

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

@@ -0,0 +1,118 @@
+package prog8.code.ast
+
+import prog8.code.core.*
+import java.nio.file.Path
+
+// New (work-in-progress) simplified AST for the code generator.
+
+
+sealed class PtNode(val position: Position) {
+
+    val children = mutableListOf<PtNode>()
+    lateinit var parent: PtNode
+
+    fun printIndented(indent: Int) {
+        print("    ".repeat(indent))
+        print("${this.javaClass.simpleName}  ")
+        printProperties()
+        println()
+        children.forEach { it.printIndented(indent+1) }
+    }
+
+    abstract fun printProperties()
+
+    fun add(child: PtNode) {
+        children.add(child)
+        child.parent = this
+    }
+
+    fun add(index: Int, child: PtNode) {
+        children.add(index, child)
+        child.parent = this
+    }
+}
+
+
+class PtNodeGroup : PtNode(Position.DUMMY) {
+    override fun printProperties() {}
+}
+
+
+abstract class PtNamedNode(val name: String, position: Position): PtNode(position) {
+    val scopedName: List<String> by lazy {
+        var namedParent: PtNode = this.parent
+        if(namedParent is PtProgram)
+            listOf(name)
+        else {
+            while (namedParent !is PtNamedNode)
+                namedParent = namedParent.parent
+            namedParent.scopedName + name
+        }
+    }
+}
+
+
+class PtProgram(
+    val name: String,
+    val memsizer: IMemSizer,
+    val encoding: IStringEncoding
+) : PtNode(Position.DUMMY) {
+    fun print() = printIndented(0)
+    override fun printProperties() {
+        print("'$name'")
+    }
+
+//    fun allModuleDirectives(): Sequence<PtDirective> =
+//        children.asSequence().flatMap { it.children }.filterIsInstance<PtDirective>().distinct()
+
+    fun allBlocks(): Sequence<PtBlock> =
+        children.asSequence().filterIsInstance<PtBlock>()
+
+    fun entrypoint(): PtSub? =
+        allBlocks().firstOrNull { it.name == "main" }?.children?.firstOrNull { it is PtSub && it.name == "start" } as PtSub?
+}
+
+
+class PtBlock(name: String,
+              val address: UInt?,
+              val library: Boolean,
+              position: Position
+) : PtNamedNode(name, position) {
+    override fun printProperties() {
+        print("$name  addr=$address  library=$library")
+    }
+}
+
+
+class PtInlineAssembly(val assembly: String, position: Position) : PtNode(position) {
+    override fun printProperties() {}
+}
+
+
+class PtLabel(name: String, position: Position) : PtNamedNode(name, position) {
+    override fun printProperties() {
+        print(name)
+    }
+}
+
+
+class PtBreakpoint(position: Position): PtNode(position) {
+    override fun printProperties() {}
+}
+
+
+class PtIncludeBinary(val file: Path, val offset: UInt?, val length: UInt?, position: Position) : PtNode(position) {
+    override fun printProperties() {
+        print("filename=$file  offset=$offset  length=$length")
+    }
+}
+
+
+class PtNop(position: Position): PtNode(position) {
+    override fun printProperties() {}
+}
+
+
+class PtScopeVarsDecls(position: Position): PtNode(position) {
+    override fun printProperties() {}
+}

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

@@ -0,0 +1,146 @@
+package prog8.code.ast
+
+import prog8.code.core.DataType
+import prog8.code.core.Encoding
+import prog8.code.core.Position
+
+
+sealed class PtExpression(val type: DataType, position: Position) : PtNode(position) {
+    override fun printProperties() {
+        print(type)
+    }
+}
+
+
+class PtAddressOf(position: Position) : PtExpression(DataType.UWORD, position) {
+    val identifier: PtIdentifier
+        get() = children.single() as PtIdentifier
+}
+
+
+class PtArrayIndexer(type: DataType, position: Position): PtExpression(type, position) {
+    val variable: PtIdentifier
+        get() = children[0] as PtIdentifier
+    val index: PtExpression
+        get() = children[1] as PtExpression
+}
+
+
+class PtArray(type: DataType, position: Position): PtExpression(type, position)
+
+
+class PtBuiltinFunctionCall(val name: String, val void: 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 }
+    override fun printProperties() {
+        print("$name void=$void")
+    }
+}
+
+
+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
+
+    override fun printProperties() {
+        print("$operator -> $type")
+    }
+}
+
+
+class PtContainmentCheck(position: Position): PtExpression(DataType.UBYTE, position) {
+    val element: PtExpression
+        get() = children[0] as PtExpression
+    val iterable: PtIdentifier
+        get() = children[1] as PtIdentifier
+}
+
+
+class PtFunctionCall(val functionName: List<String>,
+                     val void: Boolean,
+                     type: DataType,
+                     position: Position) : PtExpression(type, position) {
+    init {
+        if(!void)
+            require(type!=DataType.UNDEFINED)
+    }
+
+    val args: List<PtExpression>
+        get() = children.map { it as PtExpression }
+    override fun printProperties() {
+        print("${functionName.joinToString(".")} void=$void")
+    }
+}
+
+
+class PtIdentifier(val ref: List<String>, val targetName: List<String>, type: DataType, position: Position) : PtExpression(type, position) {
+    override fun printProperties() {
+        print("$ref --> $targetName  $type")
+    }
+}
+
+
+class PtMemoryByte(position: Position) : PtExpression(DataType.UBYTE, position) {
+    val address: PtExpression
+        get() = children.single() as PtExpression
+    override fun printProperties() {}
+}
+
+
+class PtNumber(type: DataType, val number: Double, position: Position) : PtExpression(type, position) {
+    override fun printProperties() {
+        print("$number ($type)")
+    }
+}
+
+
+class PtPipe(type: DataType, val void: Boolean, position: Position) : PtExpression(type, position) {
+    init {
+        if(!void)
+            require(type!=DataType.UNDEFINED)
+    }
+
+    override fun printProperties() {}
+}
+
+
+class PtPrefix(val operator: String, type: DataType, position: Position): PtExpression(type, position) {
+    val value: PtExpression
+        get() = children.single() as PtExpression
+
+    override fun printProperties() {
+        print(operator)
+    }
+}
+
+
+class PtRange(type: DataType, position: Position) : PtExpression(type, position) {
+    val from: PtExpression
+        get() = children[0] as PtExpression
+    val to: PtExpression
+        get() = children[1] as PtExpression
+    val step: PtNumber
+        get() = children[2] as PtNumber
+
+    override fun printProperties() {}
+}
+
+
+class PtString(val value: String, val encoding: Encoding, position: Position) : PtExpression(DataType.STR, position) {
+    override fun printProperties() {
+        print("$encoding:\"$value\"")
+    }
+}
+
+
+class PtTypeCast(type: DataType, position: Position) : PtExpression(type, position) {
+    val value: PtExpression
+        get() = children.single() as PtExpression
+}

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

@@ -0,0 +1,194 @@
+package prog8.code.ast
+
+import prog8.code.core.*
+
+
+class PtAsmSub(
+    name: String,
+    val address: UInt?,
+    val clobbers: Set<CpuRegister>,
+    val parameters: List<Pair<PtSubroutineParameter, RegisterOrStatusflag>>,
+    val retvalRegisters: List<RegisterOrStatusflag>,
+    val inline: Boolean,
+    position: Position
+) : PtNamedNode(name, position) {
+    override fun printProperties() {
+        print("$name  inline=$inline")
+    }
+}
+
+
+class PtSub(
+    name: String,
+    val parameters: List<PtSubroutineParameter>,
+    val returntype: DataType?,
+    val inline: Boolean,
+    position: Position
+) : PtNamedNode(name, position) {
+    override fun printProperties() {
+        print(name)
+    }
+}
+
+
+class PtSubroutineParameter(val name: String, val type: DataType, position: Position): PtNode(position) {
+    override fun printProperties() {
+        print("$type $name")
+    }
+}
+
+
+class PtAssignment(val augmentable: Boolean, position: Position) : PtNode(position) {
+    val target: PtAssignTarget
+        get() = children[0] as PtAssignTarget
+    val value: PtExpression
+        get() = children[1] as PtExpression
+
+    override fun printProperties() {
+        print("aug=$augmentable")
+    }
+}
+
+
+class PtAssignTarget(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       // TODO array to elt type?
+                is PtMemoryByte -> tgt.type
+                else -> throw AssemblyError("weird dt")
+            }
+        }
+
+    override fun printProperties() {}
+}
+
+
+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
+
+    override fun printProperties() {
+        print(condition)
+    }
+}
+
+
+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
+
+    override fun printProperties() {}
+}
+
+
+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
+
+    override fun printProperties() {}
+}
+
+
+class PtJump(val identifier: PtIdentifier?,
+             val address: UInt?,
+             val generatedLabel: String?,
+             position: Position) : PtNode(position) {
+    override fun printProperties() {
+        identifier?.printProperties()
+        if(address!=null) print(address.toHex())
+        if(generatedLabel!=null) print(generatedLabel)
+    }
+}
+
+
+class PtPostIncrDecr(val operator: String, position: Position) : PtNode(position) {
+    val target: PtAssignTarget
+        get() = children.single() as PtAssignTarget
+
+    override fun printProperties() {
+        print(operator)
+    }
+}
+
+
+class PtRepeatLoop(position: Position) : PtNode(position) {
+    val count: PtExpression
+        get() = children[0] as PtExpression
+    val statements: PtNodeGroup
+        get() = children[1] as PtNodeGroup
+
+    override fun printProperties() {}
+}
+
+
+class PtReturn(position: Position) : PtNode(position) {
+    val hasValue = children.any()
+    val value: PtExpression?
+        get() {
+            return if(children.any())
+                children.single() as PtExpression
+            else
+                null
+        }
+
+    override fun printProperties() {}
+}
+
+
+class PtVariable(name: String, val type: DataType, var value: PtExpression?, var arraySize: UInt?, position: Position) : PtNamedNode(name, position) {
+    override fun printProperties() {
+        print("$type  $name")
+    }
+}
+
+
+class PtConstant(name: String, val type: DataType, val value: Double, position: Position) : PtNamedNode(name, position) {
+    override fun printProperties() {
+        print("$type $name = $value")
+    }
+}
+
+
+class PtMemMapped(name: String, val type: DataType, val address: UInt, position: Position) : PtNamedNode(name, position) {
+    override fun printProperties() {
+        print("&$type $name = ${address.toHex()}")
+    }
+}
+
+
+class PtWhen(position: Position) : PtNode(position) {
+    val value: PtExpression
+        get() = children[0] as PtExpression
+    val choices: PtNodeGroup
+        get() = children[1] as PtNodeGroup
+
+    override fun printProperties() {}
+}
+
+
+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
+    override fun printProperties() {}
+}

codeCore/build.gradle

@@ -0,0 +1,43 @@
+
+plugins {
+    id 'java'
+    id 'application'
+    id "org.jetbrains.kotlin.jvm"
+}
+
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(javaVersion)
+    }
+}
+
+compileKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+compileTestKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+dependencies {
+    implementation project(':virtualmachine')
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
+    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.14"
+}
+
+sourceSets {
+    main {
+        java {
+            srcDirs = ["${project.projectDir}/src"]
+        }
+        resources {
+            srcDirs = ["${project.projectDir}/res"]
+        }
+    }
+}
+
+// note: there are no unit tests in this module!

codeCore/codeCore.iml

@@ -0,0 +1,15 @@
+<?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" />
+    <orderEntry type="module" module-name="virtualmachine" />
+  </component>
+</module>

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

@@ -0,0 +1,24 @@
+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 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 slowCodegenWarnings: Boolean = false,
+                         var optimize: Boolean = false,
+                         var optimizeFloatExpressions: Boolean = false,
+                         var dontReinitGlobals: Boolean = false,
+                         var asmQuiet: Boolean = false,
+                         var asmListfile: Boolean = false,
+                         var experimentalCodegen: Boolean = false,
+                         var outputDir: Path = Path("")
+)

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

@@ -1,9 +1,4 @@
-package prog8.ast.base
-
-import prog8.ast.Node
-
-
-/**************************** AST Data classes ****************************/
+package prog8.code.core
 
 enum class DataType {
     UBYTE,              // pass by value
@@ -23,39 +18,36 @@ enum class DataType {
      * is the type assignable to the given other type (perhaps via a typecast) without loss of precision?
      */
     infix fun isAssignableTo(targetType: DataType) =
-            when(this) {
-                UBYTE -> targetType.oneOf(UBYTE, WORD, UWORD, FLOAT)
-                BYTE -> targetType.oneOf(BYTE, WORD, FLOAT)
-                UWORD -> targetType.oneOf(UWORD, FLOAT)
-                WORD -> targetType.oneOf(WORD, FLOAT)
-                FLOAT -> targetType == FLOAT
-                STR -> targetType == STR
-                in ArrayDatatypes -> targetType == this
-                else -> false
-            }
+        when(this) {
+            UBYTE -> targetType.oneOf(UBYTE, WORD, UWORD, FLOAT)
+            BYTE -> targetType.oneOf(BYTE, WORD, FLOAT)
+            UWORD -> targetType.oneOf(UWORD, FLOAT)
+            WORD -> targetType.oneOf(WORD, FLOAT)
+            FLOAT -> targetType == FLOAT
+            STR -> targetType.oneOf(STR, UWORD)
+            in ArrayDatatypes -> targetType == this
+            else -> false
+        }
 
     fun oneOf(vararg types: DataType) = this in types
-    infix fun isAssignableTo(targetTypes: Set<DataType>) = targetTypes.any { this isAssignableTo it }
-    infix fun isNotAssignableTo(targetType: DataType) = !this.isAssignableTo(targetType)
-    infix fun isNotAssignableTo(targetTypes: Set<DataType>) = !this.isAssignableTo(targetTypes)
 
     infix fun largerThan(other: DataType) =
-            when {
-                this == other -> false
-                this in ByteDatatypes -> false
-                this in WordDatatypes -> other in ByteDatatypes
-                this== STR && other== UWORD || this== UWORD && other== STR -> false
-                else -> true
-            }
+        when {
+            this == other -> false
+            this in ByteDatatypes -> false
+            this in WordDatatypes -> other in ByteDatatypes
+            this== STR && other== UWORD || this== UWORD && other== STR -> false
+            else -> true
+        }
 
     infix fun equalsSize(other: DataType) =
-            when {
-                this == other -> true
-                this in ByteDatatypes -> other in ByteDatatypes
-                this in WordDatatypes -> other in WordDatatypes
-                this== STR && other== UWORD || this== UWORD && other== STR -> true
-                else -> false
-            }
+        when {
+            this == other -> true
+            this in ByteDatatypes -> other in ByteDatatypes
+            this in WordDatatypes -> other in WordDatatypes
+            this== STR && other== UWORD || this== UWORD && other== STR -> true
+            else -> false
+        }
 }
 
 enum class CpuRegister {
@@ -122,16 +114,12 @@ enum class BranchCondition {
     POS
 }
 
-enum class VarDeclType {
-    VAR,
-    CONST,
-    MEMORY
-}
 
 val ByteDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE)
 val WordDatatypes = arrayOf(DataType.UWORD, DataType.WORD)
 val IntegerDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD)
 val NumericDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD, DataType.FLOAT)
+val SignedDatatypes =  arrayOf(DataType.BYTE, DataType.WORD, DataType.FLOAT)
 val ArrayDatatypes = arrayOf(DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W, DataType.ARRAY_F)
 val StringlyDatatypes = arrayOf(DataType.STR, DataType.ARRAY_UB, DataType.ARRAY_B, DataType.UWORD)
 val IterableDatatypes = arrayOf(
@@ -143,19 +131,19 @@ val IterableDatatypes = arrayOf(
 val PassByValueDatatypes = NumericDatatypes
 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_F to DataType.FLOAT
+    DataType.STR to DataType.UBYTE,
+    DataType.ARRAY_B to DataType.BYTE,
+    DataType.ARRAY_UB to DataType.UBYTE,
+    DataType.ARRAY_W to DataType.WORD,
+    DataType.ARRAY_UW to DataType.UWORD,
+    DataType.ARRAY_F to DataType.FLOAT
 )
 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.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
 )
 val Cx16VirtualRegisters = arrayOf(
     RegisterOrPair.R0, RegisterOrPair.R1, RegisterOrPair.R2, RegisterOrPair.R3,
@@ -165,32 +153,29 @@ val Cx16VirtualRegisters = arrayOf(
 )
 
 
-// find the parent node of a specific type or interface
-// (useful to figure out in what namespace/block something is defined, etc.)
-inline fun <reified T> findParentNode(node: Node): T? {
-    var candidate = node.parent
-    while(candidate !is T && candidate !is ParentSentinel)
-        candidate = candidate.parent
-    return if(candidate is ParentSentinel)
-        null
-    else
-        candidate as T
+
+enum class OutputType {
+    RAW,
+    PRG,
+    XEX
 }
 
-object ParentSentinel : Node {
-    override val position = Position("<<sentinel>>", 0, 0, 0)
-    override var parent: Node = this
-    override fun linkParents(parent: Node) {}
-    override fun replaceChildNode(node: Node, replacement: Node) {
-        replacement.parent = this
-    }
+enum class CbmPrgLauncherType {
+    BASIC,
+    NONE
 }
 
-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 = "$file:$line:$startCol:"
-
-    companion object {
-        val DUMMY = Position("<dummy>", 0, 0, 0)
-    }
+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/IAssemblyGenerator.kt

@@ -0,0 +1,12 @@
+package prog8.code.core
+
+interface IAssemblyGenerator {
+    fun compileToAssembly(): IAssemblyProgram?
+}
+
+interface IAssemblyProgram {
+    val name: String
+    fun assemble(options: CompilationOptions): Boolean
+}
+
+fun viceMonListName(baseFilename: String) = "$baseFilename.vice-mon-list"

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

@@ -0,0 +1,11 @@
+package prog8.code.core
+
+interface ICompilationTarget: IStringEncoding, IMemSizer {
+    val name: String
+    val machine: IMachineDefinition
+    val supportedEncodings: Set<Encoding>
+    val defaultEncoding: Encoding
+
+    override fun encodeString(str: String, encoding: Encoding): List<UByte>
+    override fun decodeString(bytes: List<UByte>, encoding: Encoding): String
+}

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

@@ -1,7 +1,4 @@
-package prog8.compilerinterface
-
-import prog8.ast.base.Position
-
+package prog8.code.core
 
 interface IErrorReporter {
     fun err(msg: String, position: Position)
@@ -10,7 +7,6 @@ interface IErrorReporter {
     fun report()
     fun finalizeNumErrors(numErrors: Int, numWarnings: Int) {
         if(numErrors>0)
-            throw AbortCompilation("There are $numErrors errors and $numWarnings warnings.")
+            throw ErrorsReportedException("There are $numErrors errors and $numWarnings warnings.")
     }
 }
-

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

@@ -1,4 +1,4 @@
-package prog8.compilerinterface
+package prog8.code.core
 
 import java.nio.file.Path
 
@@ -10,18 +10,17 @@ interface IMachineFloat {
 
 enum class CpuType {
     CPU6502,
-    CPU65c02
+    CPU65c02,
+    VIRTUAL
 }
 
 interface IMachineDefinition {
     val FLOAT_MAX_NEGATIVE: Double
     val FLOAT_MAX_POSITIVE: Double
     val FLOAT_MEM_SIZE: Int
-    val POINTER_MEM_SIZE: Int
-    val ESTACK_LO: Int
-    val ESTACK_HI: Int
-    val BASIC_LOAD_ADDRESS : Int
-    val RAW_LOAD_ADDRESS : Int
+    val ESTACK_LO: UInt
+    val ESTACK_HI: UInt
+    val PROGRAM_LOAD_ADDRESS : UInt
 
     val opcodeNames: Set<String>
     var zeropage: Zeropage
@@ -32,5 +31,5 @@ interface IMachineDefinition {
 
     fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String>
     fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path)
-    fun isRegularRAMaddress(address: Int): Boolean
+    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 +1,14 @@
+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
+}
+
+interface IStringEncoding {
+    fun encodeString(str: String, encoding: Encoding): List<UByte>
+    fun decodeString(bytes: List<UByte>, encoding: Encoding): String
+}

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

@@ -0,0 +1,16 @@
+package prog8.code.core
+
+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 {
+        val path = Path(file).absolute().normalize()
+        return "file://$path:$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

@@ -1,27 +1,20 @@
-package prog8.parser
+package prog8.code.core
 
-import org.antlr.v4.runtime.CharStream
-import org.antlr.v4.runtime.CharStreams
 import java.io.File
 import java.io.IOException
-import java.nio.channels.Channels
-import java.nio.charset.CodingErrorAction
-import java.nio.charset.StandardCharsets
 import java.nio.file.Path
-import kotlin.io.path.*
+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].
+ * Encapsulates - and ties together - actual source code (=text) and its [origin].
  */
 sealed class SourceCode {
 
-    /**
-     * To be used *only* by the parser (as input to a TokenStream).
-     * DO NOT mess around with!
-     */
-    internal abstract fun getCharStream(): CharStream
-
     /**
      * Whether this [SourceCode] instance was created as a [Resource]
      */
@@ -32,6 +25,11 @@ sealed class SourceCode {
      */
     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:
@@ -44,11 +42,10 @@ sealed class SourceCode {
     /**
      * The source code as plain string.
      */
-    abstract fun readText(): String
+    abstract val text: String
 
     /**
-     * Deliberately does NOT return the actual text.
-     * For this - if at all - use [getCharStream].
+     * Printable representation, deliberately does NOT return the actual text.
      */
     final override fun toString() = "${this.javaClass.name}[${this.origin}]"
 
@@ -69,43 +66,40 @@ sealed class SourceCode {
      * Turn a plain String into a [SourceCode] object.
      * [origin] will be something like `$stringSourcePrefix44c56085>`.
      */
-    class Text(val text: String): SourceCode() {
+    class Text(override val text: String): SourceCode() {
         override val isFromResources = false
         override val isFromFilesystem = false
         override val origin = "$stringSourcePrefix${System.identityHashCode(text).toString(16)}>"
-        override fun getCharStream(): CharStream = CharStreams.fromString(text, origin)
-        override fun readText() = text
+        override val name = "<unnamed-text>"
     }
 
     /**
      * Get [SourceCode] from the file represented by the specified Path.
-     * This does not actually *access* the file, but it does check
-     * whether it
-     * * exists
-     * * is a regular file (ie: not a directory)
-     * * and is actually readable
+     * 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 AccessDeniedException if the given path points to a directory or the file is non-readable for some other reason
+     * @throws FileSystemException if the file cannot be read
      */
     class File(path: Path): SourceCode() {
-        private val normalized = path.normalize()
-        init {
-            val file = normalized.toFile()
-            if (!path.exists())
-                throw NoSuchFileException(file)
-            if (path.isDirectory())
-                throw AccessDeniedException(file, reason = "Not a file but a directory")
-            if (!path.isReadable())
-                throw AccessDeniedException(file, reason = "Is not readable")
-        }
-
+        override val text: String
+        override val origin: String
+        override val name: String
         override val isFromResources = false
         override val isFromFilesystem = true
-        override val origin = relative(normalized).toString()
-        override fun getCharStream(): CharStream = CharStreams.fromPath(normalized)
-        override fun readText() = normalized.readText()
+
+        init {
+            val normalized = path.normalize()
+            origin = relative(normalized).toString()
+            try {
+                text = normalized.readText()
+                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) }
+            }
+        }
     }
 
     /**
@@ -114,6 +108,12 @@ sealed class SourceCode {
     class Resource(pathString: String): SourceCode() {
         private val normalized = "/" + Path.of(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) {
@@ -123,32 +123,19 @@ sealed class SourceCode {
                     reason = "looked in resources rooted at $rscRoot"
                 )
             }
-        }
-
-        override val isFromResources = true
-        override val isFromFilesystem = false
-        override val origin = "$libraryFilePrefix$normalized"
-        public override fun getCharStream(): CharStream {
-            val inpStr = object {}.javaClass.getResourceAsStream(normalized)!!
-            // CharStreams.fromStream() doesn't allow us to set the stream name properly, so we use a lower level api
-            val channel = Channels.newChannel(inpStr)
-            return CharStreams.fromChannel(channel, StandardCharsets.UTF_8, 4096, CodingErrorAction.REPLACE, origin, -1);
-        }
-
-        override fun readText(): String {
             val stream = object {}.javaClass.getResourceAsStream(normalized)
-            return stream!!.bufferedReader().use { r -> r.readText() }
+            text = stream!!.reader().use { it.readText() }
+            name = Path.of(pathString).toFile().nameWithoutExtension
         }
     }
 
     /**
      * SourceCode for internally generated nodes (usually Modules)
      */
-    class Generated(name: String) : SourceCode() {
-        override fun getCharStream(): CharStream = throw IOException("generated code nodes doesn't have a stream to read")
+    class Generated(override val name: String) : SourceCode() {
         override val isFromResources: Boolean = false
         override val isFromFilesystem: Boolean = false
         override val origin: String = name
-        override fun readText() = throw IOException("generated code nodes don't have a text representation")
+        override val text: String = "<generated code node, no text representation>"
     }
 }

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

@@ -0,0 +1,31 @@
+package prog8.code.core
+
+import kotlin.math.abs
+
+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")
+    }
+}

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

@@ -0,0 +1,120 @@
+package prog8.code.core
+
+import com.github.michaelbull.result.Err
+import com.github.michaelbull.result.Ok
+import com.github.michaelbull.result.Result
+
+
+class ZeropageAllocationError(message: String) : Exception(message)
+
+
+abstract class Zeropage(protected val options: CompilationOptions) {
+
+    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
+
+    data class ZpAllocation(val address: UInt, val dt: DataType, val size: Int)
+
+    // the variables allocated into Zeropage.
+    // name (scoped) ==> pair of address to (Datatype + bytesize)
+    val allocatedVariables = mutableMapOf<List<String>, ZpAllocation>()
+
+    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 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 }
+    }
+
+    fun allocate(name: List<String>,
+                 datatype: DataType,
+                 numElements: Int?,
+                 position: Position?,
+                 errors: IErrorReporter
+    ): Result<Pair<UInt, Int>, ZeropageAllocationError> {
+
+        require(name.isEmpty() || name !in allocatedVariables) {"name can't be allocated twice"}
+
+        if(options.zeropage== ZeropageType.DONTUSE)
+            return Err(ZeropageAllocationError("zero page usage has been disabled"))
+
+        val size: Int =
+                when (datatype) {
+                    in IntegerDatatypes -> 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(ZeropageAllocationError("floating point option not enabled"))
+                    }
+                    else -> return Err(ZeropageAllocationError("cannot put datatype $datatype in zeropage"))
+                }
+
+        synchronized(this) {
+            if(free.size > 0) {
+                if(size==1) {
+                    for(candidate in free.minOrNull()!! .. free.maxOrNull()!!+1u) {
+                        if(oneSeparateByteFree(candidate))
+                            return Ok(Pair(makeAllocation(candidate, 1, datatype, name), 1))
+                    }
+                    return Ok(Pair(makeAllocation(free[0], 1, datatype, name), 1))
+                }
+                for(candidate in free.minOrNull()!! .. free.maxOrNull()!!+1u) {
+                    if (sequentialFree(candidate, size))
+                        return Ok(Pair(makeAllocation(candidate, size, datatype, name), size))
+                }
+            }
+        }
+
+        return Err(ZeropageAllocationError("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: List<String>): UInt {
+        require(size>=0)
+        free.removeAll(address until address+size.toUInt())
+        if(name.isNotEmpty()) {
+            allocatedVariables[name] = when(datatype) {
+                in NumericDatatypes -> ZpAllocation(address, datatype, size)        // numerical variables in zeropage never have an initial value here because they are set in separate initializer assignments
+                DataType.STR -> ZpAllocation(address, datatype, size)
+                in ArrayDatatypes -> ZpAllocation(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())
+    }
+}

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

@@ -0,0 +1,28 @@
+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 supportedEncodings = setOf(Encoding.ATASCII)
+    override val defaultEncoding = Encoding.ATASCII
+
+    companion object {
+        const val NAME = "atari"
+    }
+
+    override fun memorySize(dt: DataType): Int {
+        return when(dt) {
+            in ByteDatatypes -> 1
+            in WordDatatypes, in PassByReferenceDatatypes -> 2
+            DataType.FLOAT -> machine.FLOAT_MEM_SIZE
+            else -> Int.MIN_VALUE
+        }
+    }
+
+    override fun memorySize(arrayDt: DataType, numElements: Int) =
+        memorySize(ArrayToElementTypes.getValue(arrayDt)) * numElements
+}

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

@@ -0,0 +1,20 @@
+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 supportedEncodings = setOf(Encoding.PETSCII, Encoding.SCREENCODES)
+    override val defaultEncoding = Encoding.PETSCII
+
+    companion object {
+        const val NAME = "c128"
+    }
+}

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

@@ -0,0 +1,20 @@
+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 supportedEncodings = setOf(Encoding.PETSCII, Encoding.SCREENCODES)
+    override val defaultEncoding = Encoding.PETSCII
+
+    companion object {
+        const val NAME = "c64"
+    }
+}

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

@@ -0,0 +1,20 @@
+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 supportedEncodings = setOf(Encoding.PETSCII, Encoding.SCREENCODES, Encoding.ISO)
+    override val defaultEncoding = Encoding.PETSCII
+
+    companion object {
+        const val NAME = "cx16"
+    }
+}

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

@@ -0,0 +1,39 @@
+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.cbm.AtasciiEncoding
+import prog8.code.target.cbm.IsoEncoding
+import prog8.code.target.cbm.PetsciiEncoding
+
+
+object Encoder: IStringEncoding {
+    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)
+            else -> throw InternalCompilerException("unsupported encoding $encoding")
+        }
+        return coded.fold(
+            failure = { throw it },
+            success = { it }
+        )
+    }
+    override fun decodeString(bytes: List<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)
+            else -> throw InternalCompilerException("unsupported encoding $encoding")
+        }
+        return decoded.fold(
+            failure = { throw it },
+            success = { it }
+        )
+    }
+}

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

@@ -0,0 +1,27 @@
+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 supportedEncodings = setOf(Encoding.ISO)
+    override val defaultEncoding = Encoding.ISO
+
+    companion object {
+        const val NAME = "virtual"
+    }
+
+    override fun memorySize(dt: DataType): Int {
+        return when(dt) {
+            in ByteDatatypes -> 1
+            in WordDatatypes, in PassByReferenceDatatypes -> 2
+            DataType.FLOAT -> machine.FLOAT_MEM_SIZE
+            else -> Int.MIN_VALUE
+        }
+    }
+
+    override fun memorySize(arrayDt: DataType, numElements: Int) =
+        memorySize(ArrayToElementTypes.getValue(arrayDt)) * numElements
+}

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

@@ -0,0 +1,65 @@
+package prog8.code.target.atari
+
+import prog8.code.core.*
+import prog8.code.target.c64.normal6502instructions
+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
+
+    // the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
+    override val ESTACK_LO = 0x1a00u     //  $1a00-$1aff inclusive      // TODO
+    override val ESTACK_HI = 0x1b00u     //  $1b00-$1bff inclusive      // TODO
+
+    override lateinit var zeropage: Zeropage
+
+    override fun getFloat(num: Number) = TODO("float from number")
+
+    override fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
+        return if (compilerOptions.output == OutputType.XEX)
+            listOf("syslib")
+        else
+            emptyList()
+    }
+
+    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
+        val emulatorName: String
+        val cmdline: List<String>
+        when(selectedEmulator) {
+            1 -> {
+                emulatorName = "atari800"
+                cmdline = listOf(emulatorName, "-xl", "-xl-rev", "2", "-nobasic", "-run", "${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 initializeZeropage(compilerOptions: CompilationOptions) {
+        zeropage = AtariZeropage(compilerOptions)
+    }
+
+    override val opcodeNames = normal6502instructions
+}

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

@@ -0,0 +1,45 @@
+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 && 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
+            }
+        }
+
+        removeReservedFromFreePool()
+    }
+}

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

@@ -0,0 +1,55 @@
+package prog8.code.target.c128
+
+import prog8.code.core.*
+import prog8.code.target.c64.normal6502instructions
+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
+
+    // the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
+    override val ESTACK_LO = 0x1a00u     //  $1a00-$1aff inclusive
+    override val ESTACK_HI = 0x1b00u     //  $1b00-$1bff inclusive
+
+    override lateinit var zeropage: Zeropage
+
+    override fun getFloat(num: Number) = Mflpt5.fromNumber(num)
+
+    override fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
+        return if (compilerOptions.launcher == CbmPrgLauncherType.BASIC || compilerOptions.output == OutputType.PRG)
+            listOf("syslib")
+        else
+            emptyList()
+    }
+
+    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
+        if(selectedEmulator!=1) {
+            System.err.println("The c128 target only supports the main emulator (Vice).")
+            return
+        }
+
+        println("\nStarting C-128 emulator x128...")
+        val viceMonlist = viceMonListName(programNameWithPath.toString())
+        val cmdline = listOf("x128", "-silent", "-moncommands", viceMonlist,
+                "-autostartprgmode", "1", "-autostart-warp", "-autostart", "${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 initializeZeropage(compilerOptions: CompilationOptions) {
+        zeropage = C128Zeropage(compilerOptions)
+    }
+
+    override val opcodeNames = normal6502instructions
+}

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

@@ -0,0 +1,43 @@
+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
+
+
+class C128Zeropage(options: CompilationOptions) : Zeropage(options) {
+
+    override val SCRATCH_B1 = 0x9bu      // temp storage for a single byte
+    override val SCRATCH_REG = 0x9cu     // 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'")
+
+        when (options.zeropage) {
+            ZeropageType.FULL -> {
+                // TODO all c128 usable zero page locations, except the ones used by the system's IRQ routine
+                free.addAll(0x0au..0xffu)       // TODO c128 what about $02-$09?
+                // TODO c128  free.removeAll(setOf(0xa0u, 0xa1u, 0xa2u, 0x91u, 0xc0u, 0xc5u, 0xcbu, 0xf5u, 0xf6u))        // these are updated by IRQ
+            }
+            ZeropageType.KERNALSAFE,
+            ZeropageType.FLOATSAFE,
+            ZeropageType.BASICSAFE -> {
+                free.clear()   // TODO c128 usable zero page addresses
+            }
+            ZeropageType.DONTUSE -> {
+                free.clear()  // don't use zeropage at all
+            }
+        }
+
+        removeReservedFromFreePool()
+    }
+}

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

@@ -0,0 +1,76 @@
+package prog8.code.target.c64
+
+import prog8.code.core.*
+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
+
+    // the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
+    override val ESTACK_LO = 0xce00u     //  $ce00-$ceff inclusive
+    override val ESTACK_HI = 0xcf00u     //  $ce00-$ceff inclusive
+
+    override lateinit var zeropage: Zeropage
+
+    override fun getFloat(num: Number) = Mflpt5.fromNumber(num)
+
+    override fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
+        return if (compilerOptions.launcher == CbmPrgLauncherType.BASIC || compilerOptions.output == OutputType.PRG)
+            listOf("syslib")
+        else
+            emptyList()
+    }
+
+    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 $emulator...")
+            val viceMonlist = viceMonListName(programNameWithPath.toString())
+            val cmdline = listOf(emulator, "-silent", "-moncommands", viceMonlist,
+                    "-autostartprgmode", "1", "-autostart-warp", "-autostart", "${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 initializeZeropage(compilerOptions: CompilationOptions) {
+        zeropage = C64Zeropage(compilerOptions)
+    }
+
+    override val opcodeNames = normal6502instructions
+}
+
+
+// 6502 opcodes (including aliases and illegal opcodes), these cannot be used as variable or label names
+internal val normal6502instructions = setOf(
+    "adc", "ahx", "alr", "anc", "and", "ane", "arr", "asl", "asr", "axs", "bcc", "bcs",
+    "beq", "bge", "bit", "blt", "bmi", "bne", "bpl", "brk", "bvc", "bvs", "clc",
+    "cld", "cli", "clv", "cmp", "cpx", "cpy", "dcm", "dcp", "dec", "dex", "dey",
+    "eor", "gcc", "gcs", "geq", "gge", "glt", "gmi", "gne", "gpl", "gvc", "gvs",
+    "inc", "ins", "inx", "iny", "isb", "isc", "jam", "jmp", "jsr", "lae", "las",
+    "lax", "lda", "lds", "ldx", "ldy", "lsr", "lxa", "nop", "ora", "pha", "php",
+    "pla", "plp", "rla", "rol", "ror", "rra", "rti", "rts", "sax", "sbc", "sbx",
+    "sec", "sed", "sei", "sha", "shl", "shr", "shs", "shx", "shy", "slo", "sre",
+    "sta", "stx", "sty", "tas", "tax", "tay", "tsx", "txa", "txs", "tya", "xaa")

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

@@ -0,0 +1,74 @@
+package prog8.code.target.c64
+
+import prog8.code.core.CompilationOptions
+import prog8.code.core.InternalCompilerException
+import prog8.code.core.Zeropage
+import prog8.code.core.ZeropageType
+
+
+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(
+                        0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
+                        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(
+                        0x22, 0x23, 0x24, 0x25,
+                        0x10, 0x11, 0x12, 0x26, 0x27, 0x28, 0x29, 0x2a,
+                        0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
+                        0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+                        0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72,
+                        0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 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(0x04, 0x05, 0x06, 0x0a, 0x0e,
+                        0x92, 0x96, 0x9b, 0x9c, 0x9e, 0x9f, 0xa5, 0xa6,
+                        0xb0, 0xb1, 0xbe, 0xbf, 0xf9).map{it.toUInt()})
+            } else {
+                // don't use the zeropage at all
+                free.clear()
+            }
+        }
+
+        removeReservedFromFreePool()
+    }
+}

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

@@ -0,0 +1,214 @@
+package prog8.code.target.cbm
+
+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: List<UByte>): Result<String, CharConversionException> {
+        return Ok(bytes.map { decodeTable[it.toInt()] }.joinToString(""))
+    }
+}

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

@@ -0,0 +1,18 @@
+package prog8.code.target.cbm
+
+import prog8.code.core.*
+
+
+internal object CbmMemorySizer: IMemSizer {
+    override fun memorySize(dt: DataType): Int {
+        return when(dt) {
+            in ByteDatatypes -> 1
+            in WordDatatypes, in PassByReferenceDatatypes -> 2
+            DataType.FLOAT -> Mflpt5.FLOAT_MEM_SIZE
+            else -> Int.MIN_VALUE
+        }
+    }
+
+    override fun memorySize(arrayDt: DataType, numElements: Int) =
+        memorySize(ArrayToElementTypes.getValue(arrayDt)) * numElements
+}

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

@@ -0,0 +1,37 @@
+package prog8.code.target.cbm
+
+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 IsoEncoding {
+    val charset: Charset = Charset.forName("ISO-8859-15")
+
+    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: List<UByte>): Result<String, CharConversionException> {
+        return try {
+            Ok(String(bytes.map { it.toByte() }.toByteArray(), charset))
+        } catch (ce: CharConversionException) {
+            Err(ce)
+        }
+    }
+}

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

@@ -0,0 +1,78 @@
+package prog8.code.target.cbm
+
+import prog8.code.core.IMachineFloat
+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): IMachineFloat {
+
+    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: $this")
+                exponent == 0 -> zero
+                else -> {
+                    val mantLong = mantissa.toLong()
+                    Mflpt5(
+                        exponent.toUByte(),
+                        (mantLong.and(0x7f000000L) ushr 24).or(sign).toUByte(),
+                        (mantLong.and(0x00ff0000L) ushr 16).toUByte(),
+                        (mantLong.and(0x0000ff00L) ushr 8).toUByte(),
+                        (mantLong.and(0x000000ffL)).toUByte()
+                    )
+                }
+            }
+        }
+    }
+
+    override fun toDouble(): Double {
+        if (this == zero) return 0.0
+        val exp = b0.toInt() - 128
+        val sign = (b1.toInt() and 0x80) > 0
+        val number = 0x80000000L.or(b1.toLong() shl 24).or(b2.toLong() shl 16).or(b3.toLong() shl 8).or(b4.toLong())
+        val result = number.toDouble() * (2.0).pow(exp) / 0x100000000
+        return if (sign) -result else result
+    }
+
+    override fun makeFloatFillAsm(): String {
+        val b0 = "$" + 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/cbm/PetsciiEncoding.kt

@@ -1,15 +1,14 @@
-package prog8.compiler.target.cbm
+package prog8.code.target.cbm
 
 import com.github.michaelbull.result.Err
 import com.github.michaelbull.result.Ok
 import com.github.michaelbull.result.Result
-import prog8.ast.antlr.escape
 import java.io.CharConversionException
 
-object Petscii {
+object PetsciiEncoding {
 
     // decoding:  from Petscii/Screencodes (0-255) to unicode
-    // character tables used from https://github.com/dj51d/cbmcodecs
+    // character tables used from https://github.com/irmen/cbmcodecs2
 
     private val decodingPetsciiLowercase = charArrayOf(
         '\u0000',    //       0x00 -> \u0000
@@ -159,7 +158,7 @@ object Petscii {
         '\uf105',    //       0x90 -> BLACK COLOR SWITCH (CUS)
         '\uf11e',    //      0x91 -> CURSOR UP (CUS)
         '\uf11b',    //      0x92 -> REVERSE VIDEO OFF (CUS)
-        '\u000c',    //       0x93 -> FORM FEED
+        '\u000c',    //       0x93 -> FORM FEED (CLEAR SCREEN)
         '\uf121',    //      0x94 -> INSERT (CUS)
         '\uf106',    //       0x95 -> BROWN COLOR SWITCH (CUS)
         '\uf107',    //       0x96 -> LIGHT RED COLOR SWITCH (CUS)
@@ -195,7 +194,7 @@ object Petscii {
         '\u258e',    //  ▎    0xB4 -> LEFT ONE QUARTER BLOCK
         '\u258d',    //  ▍    0xB5 -> LEFT THREE EIGTHS BLOCK
         '\uf131',    //      0xB6 -> RIGHT THREE EIGHTHS BLOCK (CUS)
-        '\uf132',    //      0xB7 -> UPPER ONE QUARTER BLOCK (CUS)
+        '\uf132',    //  🮂    0xB7 -> UPPER ONE QUARTER BLOCK (CUS)
         '\uf133',    //      0xB8 -> UPPER THREE EIGHTS BLOCK (CUS)
         '\u2583',    //  ▃    0xB9 -> LOWER THREE EIGHTHS BLOCK
         '\u2713',    //  ✓    0xBA -> CHECK MARK
@@ -246,7 +245,7 @@ object Petscii {
         '\u2595',    //  ▕    0xE7 -> RIGHT ONE EIGHTH BLOCK
         '\uf12f',    //      0xE8 -> LOWER HALF BLOCK MEDIUM SHADE (CUS)
         '\uf13a',    //      0xE9 -> MEDIUM SHADE SLASHED RIGHT (CUS)
-        '\uf130',    //      0xEA -> RIGHT ONE QUARTER BLOCK (CUS)
+        '\uf130',    //  🮇    0xEA -> RIGHT ONE QUARTER BLOCK (CUS)
         '\u251c',    //  ├    0xEB -> BOX DRAWINGS LIGHT VERTICAL AND RIGHT
         '\u2597',    //  ▗    0xEC -> QUADRANT LOWER RIGHT
         '\u2514',    //  └    0xED -> BOX DRAWINGS LIGHT UP AND RIGHT
@@ -418,7 +417,7 @@ object Petscii {
         '\uf105',    //       0x90 -> BLACK COLOR SWITCH (CUS)
         '\uf11e',    //       0x91 -> CURSOR UP (CUS)
         '\uf11b',    //       0x92 -> REVERSE VIDEO OFF (CUS)
-        '\u000c',    //       0x93 -> FORM FEED
+        '\u000c',    //       0x93 -> FORM FEED (CLEAR SCREEN)
         '\uf121',    //       0x94 -> INSERT (CUS)
         '\uf106',    //       0x95 -> BROWN COLOR SWITCH (CUS)
         '\uf107',    //       0x96 -> LIGHT RED COLOR SWITCH (CUS)
@@ -1065,19 +1064,19 @@ object Petscii {
             else -> chr
         }
 
-    fun encodePetscii(text: String, lowercase: Boolean = false): Result<List<Short>, CharConversionException> {
-        fun encodeChar(chr3: Char, lowercase: Boolean): Short {
+    fun encodePetscii(text: String, lowercase: Boolean = false): Result<List<UByte>, CharConversionException> {
+        fun encodeChar(chr3: Char, lowercase: Boolean): UByte {
             val chr = replaceSpecial(chr3)
             val screencode = if(lowercase) encodingPetsciiLowercase[chr] else encodingPetsciiUppercase[chr]
-            return screencode?.toShort() ?: when (chr) {
-                '\u0000' -> 0.toShort()
+            return screencode?.toUByte() ?: when (chr) {
+                '\u0000' -> 0u
                 in '\u8000'..'\u80ff' -> {
                     // special case: take the lower 8 bit hex value directly
-                    (chr.code - 0x8000).toShort()
+                    (chr.code - 0x8000).toUByte()
                 }
                 else -> {
                     val case = if (lowercase) "lower" else "upper"
-                    throw CharConversionException("no ${case}Petscii character for '${escape(chr.toString())}' (${chr.code})")
+                    throw CharConversionException("no ${case}Petscii character for '${chr}' (${chr.code})")
                 }
             }
         }
@@ -1095,28 +1094,32 @@ object Petscii {
         }
     }
 
-    fun decodePetscii(petscii: Iterable<Short>, lowercase: Boolean = false): String {
-        return petscii.map {
-            val code = it.toInt()
-            if(code<0 || code>= decodingPetsciiLowercase.size)
-                throw CharConversionException("petscii $code out of range 0..${decodingPetsciiLowercase.size-1}")
-            if(lowercase) decodingPetsciiLowercase[code] else decodingPetsciiUppercase[code]
-        }.joinToString("")
+    fun decodePetscii(petscii: Iterable<UByte>, lowercase: Boolean = false): Result<String, CharConversionException> {
+        return try {
+            Ok(petscii.map {
+                val code = it.toInt()
+                if(code<0 || code>= decodingPetsciiLowercase.size)
+                    throw CharConversionException("petscii $code out of range 0..${decodingPetsciiLowercase.size-1}")
+                if(lowercase) decodingPetsciiLowercase[code] else decodingPetsciiUppercase[code]
+            }.joinToString(""))
+        } catch(ce: CharConversionException) {
+            return Err(ce)
+        }
     }
 
-    fun encodeScreencode(text: String, lowercase: Boolean = false): Result<List<Short>, CharConversionException> {
-        fun encodeChar(chr3: Char, lowercase: Boolean): Short {
+    fun encodeScreencode(text: String, lowercase: Boolean = false): Result<List<UByte>, CharConversionException> {
+        fun encodeChar(chr3: Char, lowercase: Boolean): UByte {
             val chr = replaceSpecial(chr3)
             val screencode = if(lowercase) encodingScreencodeLowercase[chr] else encodingScreencodeUppercase[chr]
-            return screencode?.toShort() ?: when (chr) {
-                '\u0000' -> 0.toShort()
+            return screencode?.toUByte() ?: when (chr) {
+                '\u0000' -> 0u
                 in '\u8000'..'\u80ff' -> {
                     // special case: take the lower 8 bit hex value directly
-                    (chr.code - 0x8000).toShort()
+                    (chr.code - 0x8000).toUByte()
                 }
                 else -> {
                     val case = if (lowercase) "lower" else "upper"
-                    throw CharConversionException("no ${case}Screencode character for '${escape(chr.toString())}' (${chr.code})")
+                    throw CharConversionException("no ${case}Screencode character for '${chr}' (${chr.code})")
                 }
             }
         }
@@ -1134,47 +1137,50 @@ object Petscii {
         }
     }
 
-    fun decodeScreencode(screencode: Iterable<Short>, lowercase: Boolean = false): String {
-        return screencode.map {
-            val code = it.toInt()
-            if(code<0 || code>= decodingScreencodeLowercase.size)
-                throw CharConversionException("screencode $code out of range 0..${decodingScreencodeLowercase.size-1}")
-            if (lowercase) decodingScreencodeLowercase[code] else decodingScreencodeUppercase[code]
-        }.joinToString("")
+    fun decodeScreencode(screencode: Iterable<UByte>, lowercase: Boolean = false): Result<String, CharConversionException> {
+        return try {
+            Ok(screencode.map {
+                val code = it.toInt()
+                if(code<0 || code>= decodingScreencodeLowercase.size)
+                    throw CharConversionException("screencode $code out of range 0..${decodingScreencodeLowercase.size-1}")
+                if (lowercase) decodingScreencodeLowercase[code] else decodingScreencodeUppercase[code]
+            }.joinToString(""))
+        } catch(ce: CharConversionException) {
+            Err(ce)
+        }
     }
 
-    fun petscii2scr(petscii_code: Short, inverseVideo: Boolean): Result<Short, CharConversionException> {
-        val code = when {
-            petscii_code < 0 -> return Err(CharConversionException("petscii code out of range"))
-            petscii_code <= 0x1f -> petscii_code + 128
-            petscii_code <= 0x3f -> petscii_code.toInt()
-            petscii_code <= 0x5f -> petscii_code - 64
-            petscii_code <= 0x7f -> petscii_code - 32
-            petscii_code <= 0x9f -> petscii_code + 64
-            petscii_code <= 0xbf -> petscii_code - 64
-            petscii_code <= 0xfe -> petscii_code - 128
-            petscii_code == 255.toShort() -> 95
+    fun petscii2scr(petscii_code: UByte, inverseVideo: Boolean): Result<UByte, CharConversionException> {
+        val code: UInt = when {
+            petscii_code <= 0x1fu -> petscii_code + 128u
+            petscii_code <= 0x3fu -> petscii_code.toUInt()
+            petscii_code <= 0x5fu -> petscii_code - 64u
+            petscii_code <= 0x7fu -> petscii_code - 32u
+            petscii_code <= 0x9fu -> petscii_code + 64u
+            petscii_code <= 0xbfu -> petscii_code - 64u
+            petscii_code <= 0xfeu -> petscii_code - 128u
+            petscii_code == 255.toUByte() -> 95u
             else -> return Err(CharConversionException("petscii code out of range"))
         }
-        if(inverseVideo)
-            return Ok((code or 0x80).toShort())
-        return Ok(code.toShort())
+        if(inverseVideo) {
+            return Ok((code or 0x80u).toUByte())
+        }
+        return Ok(code.toUByte())
     }
 
-    fun scr2petscii(screencode: Short): Result<Short, CharConversionException> {
-        val petscii = when {
-            screencode < 0 -> return Err(CharConversionException("screencode out of range"))
-            screencode <= 0x1f -> screencode + 64
-            screencode <= 0x3f -> screencode.toInt()
-            screencode <= 0x5d -> screencode +123
-            screencode == 0x5e.toShort() -> 255
-            screencode == 0x5f.toShort() -> 223
-            screencode <= 0x7f -> screencode + 64
-            screencode <= 0xbf -> screencode - 128
-            screencode <= 0xfe -> screencode - 64
-            screencode == 255.toShort() -> 191
+    fun scr2petscii(screencode: UByte): Result<UByte, CharConversionException> {
+        val petscii: UInt = when {
+            screencode <= 0x1fu -> screencode + 64u
+            screencode <= 0x3fu -> screencode.toUInt()
+            screencode <= 0x5du -> screencode +123u
+            screencode == 0x5e.toUByte() -> 255u
+            screencode == 0x5f.toUByte() -> 223u
+            screencode <= 0x7fu -> screencode + 64u
+            screencode <= 0xbfu -> screencode - 128u
+            screencode <= 0xfeu -> screencode - 64u
+            screencode == 255.toUByte() -> 191u
             else -> return Err(CharConversionException("screencode out of range"))
         }
-        return Ok(petscii.toShort())
+        return Ok(petscii.toUByte())
     }
 }

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

@@ -0,0 +1,77 @@
+package prog8.code.target.cx16
+
+import prog8.code.core.*
+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
+
+    // the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
+    override val ESTACK_LO = 0x0400u        //  $0400-$04ff inclusive
+    override val ESTACK_HI = 0x0500u        //  $0500-$05ff inclusive
+
+    override lateinit var zeropage: Zeropage
+
+    override fun getFloat(num: Number) = Mflpt5.fromNumber(num)
+    override fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
+        return if (compilerOptions.launcher == CbmPrgLauncherType.BASIC || compilerOptions.output == OutputType.PRG)
+            listOf("syslib")
+        else
+            emptyList()
+    }
+
+    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
+        val emulator: String
+        val extraArgs: List<String>
+
+        when(selectedEmulator) {
+            1 -> {
+                emulator = "x16emu"
+                extraArgs = emptyList()
+            }
+            2 -> {
+                emulator = "box16"
+                extraArgs = listOf("-sym", viceMonListName(programNameWithPath.toString()))
+            }
+            else -> {
+                System.err.println("Cx16 target only supports x16emu and box16 emulators.")
+                return
+            }
+        }
+
+        println("\nStarting Commander X16 emulator $emulator...")
+        val cmdline = listOf(emulator, "-scale", "2", "-run", "-prg", "${programNameWithPath}.prg") + extraArgs
+        val processb = ProcessBuilder(cmdline).inheritIO()
+        val process: Process = processb.start()
+        process.waitFor()
+    }
+
+    override fun isIOAddress(address: UInt): Boolean = address==0u || address==1u || address in 0x9f00u..0x9fffu
+
+    override fun initializeZeropage(compilerOptions: CompilationOptions) {
+        zeropage = CX16Zeropage(compilerOptions)
+    }
+
+    // 65c02 opcodes, these cannot be used as variable or label names
+    override val opcodeNames = setOf("adc", "and", "asl", "bcc", "bcs",
+            "beq", "bge", "bit", "blt", "bmi", "bne", "bpl", "brk", "bvc", "bvs", "clc",
+            "cld", "cli", "clv", "cmp", "cpx", "cpy", "dec", "dex", "dey",
+            "eor", "gcc", "gcs", "geq", "gge", "glt", "gmi", "gne", "gpl", "gvc", "gvs",
+            "inc", "inx", "iny", "jmp", "jsr",
+            "lda", "ldx", "ldy", "lsr", "nop", "ora", "pha", "php",
+            "pla", "plp", "rol", "ror", "rti", "rts", "sbc",
+            "sec", "sed", "sei",
+            "sta", "stx", "sty", "tax", "tay", "tsx", "txa", "txs", "tya",
+            "bra", "phx", "phy", "plx", "ply", "stz", "trb", "tsb", "bbr", "bbs",
+            "rmb", "smb", "stp", "wai")
+
+
+}

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

@@ -0,0 +1,60 @@
+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
+                }
+                else -> throw InternalCompilerException("for this machine target, zero page type 'floatsafe' is not available. ${options.zeropage}")
+            }
+
+            removeReservedFromFreePool()
+
+            // note: the 16 virtual registers R0-R15 are not regular allocated variables, they're *memory mapped* elsewhere to fixed addresses.
+            // however, to be able for the compiler to "see" them as zero page variables, we have to register them here as well.
+            for(reg in 0..15) {
+                allocatedVariables[listOf("cx16", "r${reg}")]   = ZpAllocation((2+reg*2).toUInt(), DataType.UWORD, 2)        // cx16.r0 .. cx16.r15
+                allocatedVariables[listOf("cx16", "r${reg}s")]  = ZpAllocation((2+reg*2).toUInt(), DataType.WORD, 2)        // cx16.r0s .. cx16.r15s
+                allocatedVariables[listOf("cx16", "r${reg}L")]  = ZpAllocation((2+reg*2).toUInt(), DataType.UBYTE, 1)       // cx16.r0L .. cx16.r15L
+                allocatedVariables[listOf("cx16", "r${reg}H")]  = ZpAllocation((3+reg*2).toUInt(), DataType.UBYTE, 1)       // cx16.r0H .. cx16.r15H
+                allocatedVariables[listOf("cx16", "r${reg}sL")] = ZpAllocation((2+reg*2).toUInt(), DataType.BYTE, 1)       // cx16.r0sL .. cx16.r15sL
+                allocatedVariables[listOf("cx16", "r${reg}sH")] = ZpAllocation((3+reg*2).toUInt(), DataType.BYTE, 1)       // cx16.r0sH .. cx16.r15sH
+            }
+        }
+    }
+}

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

@@ -0,0 +1,51 @@
+package prog8.code.target.virtual
+
+import prog8.code.core.CompilationOptions
+import prog8.code.core.CpuType
+import prog8.code.core.IMachineDefinition
+import prog8.code.core.Zeropage
+import prog8.vm.Assembler
+import prog8.vm.Memory
+import prog8.vm.VirtualMachine
+import java.io.File
+import java.nio.file.Path
+
+
+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 = 4
+    override val PROGRAM_LOAD_ADDRESS = 0u      // not actually used
+
+    override val ESTACK_LO = 0u                 // not actually used
+    override val ESTACK_HI = 0u                 // not actually used
+
+    override lateinit var zeropage: Zeropage     // not actually used
+
+    override fun getFloat(num: Number) = TODO("float from number")
+
+    override fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
+        return listOf("syslib")
+    }
+
+    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
+        println("\nStarting Virtual Machine...")
+        val source = File("$programNameWithPath.p8virt").readText()
+        val (memsrc, programsrc) = source.split("------PROGRAM------".toRegex(), 2)
+        val memory = Memory()
+        val assembler = Assembler()
+        assembler.initializeMemory(memsrc, memory)
+        val program = assembler.assembleProgram(programsrc)
+        val vm = VirtualMachine(memory, program)
+        vm.run(throttle = true)
+    }
+
+    override fun isIOAddress(address: UInt): Boolean = false
+
+    override fun initializeZeropage(compilerOptions: CompilationOptions) {}
+
+    override val opcodeNames = emptySet<String>()
+}

codeGenCpu6502/build.gradle

@@ -11,17 +11,25 @@ java {
     }
 }
 
+compileKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+compileTestKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
 dependencies {
-    implementation project(':compilerInterfaces')
+    implementation project(':codeAst')
+    implementation project(':codeCore')
     implementation project(':compilerAst')
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
     // implementation "org.jetbrains.kotlin:kotlin-reflect"
-    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.12"
-
-    testImplementation "org.jetbrains.kotlin:kotlin-test-junit5"
-    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.7.2'
-    testImplementation 'org.hamcrest:hamcrest:2.2'
-    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.7.2'
+    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.14"
 
 }
 
@@ -34,23 +42,6 @@ sourceSets {
             srcDirs = ["${project.projectDir}/res"]
         }
     }
-    test {
-        java {
-            srcDirs = ["${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"
-    }
-}
+// note: there are no unit tests in this module!

codeGenCpu6502/codeGenCpu6502.iml

@@ -4,16 +4,14 @@
     <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="jdk" jdkName="openjdk-11" jdkType="JavaSDK" />
+    <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" />
-    <orderEntry type="module" module-name="compilerInterfaces" />
+    <orderEntry type="module" module-name="codeAst" />
+    <orderEntry type="module" module-name="codeCore" />
     <orderEntry type="module" module-name="compilerAst" />
-    <orderEntry type="library" scope="TEST" name="hamcrest" level="project" />
-    <orderEntry type="library" name="junit.jupiter" level="project" />
+    <orderEntry type="library" name="michael.bull.kotlin.result.jvm" level="project" />
   </component>
 </module>

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

@@ -0,0 +1,452 @@
+package prog8.codegen.cpu6502
+
+import prog8.ast.Program
+import prog8.ast.expressions.NumericLiteral
+import prog8.ast.statements.VarDecl
+import prog8.ast.statements.VarDeclType
+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, program: Program): Int {
+
+    var numberOfOptimizations = 0
+
+    var linesByFour = getLinesBy(lines, 4)
+
+    var mods = optimizeUselessStackByteWrites(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    mods = optimizeIncDec(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    mods = optimizeCmpSequence(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    mods = optimizeStoreLoadSame(linesByFour, machine, program)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    mods= optimizeJsrRts(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    var linesByFourteen = getLinesBy(lines, 14)
+    mods = optimizeSameAssignments(linesByFourteen, machine, program)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFourteen = getLinesBy(lines, 14)
+        numberOfOptimizations++
+    }
+
+    // TODO more assembly optimizations
+
+    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?)
+
+private fun apply(modifications: List<Modification>, lines: MutableList<String>) {
+    for (modification in modifications.sortedBy { it.lineIndex }.reversed()) {
+        if(modification.remove)
+            lines.removeAt(modification.lineIndex)
+        else
+            lines[modification.lineIndex] = modification.replacement!!
+    }
+}
+
+private fun getLinesBy(lines: MutableList<String>, windowSize: Int) =
+// all lines (that aren't empty or comments) in sliding windows of certain size
+        lines.withIndex().filter { it.value.isNotBlank() && !it.value.trimStart().startsWith(';') }.windowed(windowSize, partialWindows = false)
+
+private fun optimizeCmpSequence(linesByFour: List<List<IndexedValue<String>>>): List<Modification> {
+    // when statement (on bytes) generates a sequence of:
+    //	 lda  $ce01,x
+    //	 cmp  #$20
+    //	 beq  check_prog8_s72choice_32
+    //	 lda  $ce01,x
+    //	 cmp  #$21
+    //	 beq  check_prog8_s73choice_33
+    // the repeated lda can be removed
+    val mods = mutableListOf<Modification>()
+    for(lines in linesByFour) {
+        if(lines[0].value.trim()=="lda  P8ESTACK_LO+1,x" &&
+                lines[1].value.trim().startsWith("cmp ") &&
+                lines[2].value.trim().startsWith("beq ") &&
+                lines[3].value.trim()=="lda  P8ESTACK_LO+1,x") {
+            mods.add(Modification(lines[3].index, true, null)) // remove the second lda
+        }
+    }
+    return mods
+}
+
+private fun optimizeUselessStackByteWrites(linesByFour: List<List<IndexedValue<String>>>): List<Modification> {
+    // sta on stack, dex, inx, lda from stack -> eliminate this useless stack byte write
+    // this is a lot harder for word values because the instruction sequence varies.
+    val mods = mutableListOf<Modification>()
+    for(lines in linesByFour) {
+        if(lines[0].value.trim()=="sta  P8ESTACK_LO,x" &&
+                lines[1].value.trim()=="dex" &&
+                lines[2].value.trim()=="inx" &&
+                lines[3].value.trim()=="lda  P8ESTACK_LO,x") {
+            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 optimizeSameAssignments(linesByFourteen: List<List<IndexedValue<String>>>, machine: IMachineDefinition, program: Program): 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, program)
+                val address2 = getAddressArg(second, program)
+                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, program)
+                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, program)
+                    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, program)
+                    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, program)
+                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
+         */
+        if(!overlappingMods && first.isStoreRegOrZero() && second.isStoreRegOrZero()) {
+            if(first[2]==second[2]) {
+                val firstvalue = first.substring(4)
+                val secondvalue = second.substring(4)
+                if(firstvalue==secondvalue) {
+                    val address = getAddressArg(first, program)
+                    if(address==null || !machine.isIOAddress(address)) {
+                        overlappingMods = true
+                        mods.add(Modification(lines[0].index, true, null))
+                    }
+                }
+            }
+        }
+    }
+
+    return mods
+}
+
+private fun optimizeStoreLoadSame(linesByFour: List<List<IndexedValue<String>>>, machine: IMachineDefinition, program: Program): List<Modification> {
+    // sta X + lda X,  sty X + ldy X,   stx X + ldx X  -> the second instruction can OFTEN be eliminated
+    val mods = mutableListOf<Modification>()
+    for (lines in linesByFour) {
+        val first = lines[1].value.trimStart()
+        val second = lines[2].value.trimStart()
+
+        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 ")) ||
+                (first.startsWith("sta ") && second.startsWith("lda ")) ||
+                (first.startsWith("sty ") && second.startsWith("ldy ")) ||
+                (first.startsWith("stx ") && second.startsWith("ldx "))
+        ) {
+            val third = lines[3].value.trimStart()
+            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, program)
+                    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=="phx" && second=="ply") {
+            mods.add(Modification(lines[1].index, true, null))
+            mods.add(Modification(lines[2].index, false, "  txy"))
+        } else if(first=="phy" && second=="pla") {
+            mods.add(Modification(lines[1].index, true, null))
+            mods.add(Modification(lines[2].index, false, "  tya"))
+        } else if(first=="phy" && second=="plx") {
+            mods.add(Modification(lines[1].index, true, null))
+            mods.add(Modification(lines[2].index, false, "  tyx"))
+        }
+    }
+    return mods
+}
+
+private val identifierRegex = Regex("""^([a-zA-Z_$][a-zA-Z\d_\.$]*)""")
+
+private fun getAddressArg(line: String, program: Program): UInt? {
+    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
+                val decl = program.toplevelModule.lookup(identifier.split(".")) as? VarDecl
+                if(decl!=null) {
+                    when(decl.type){
+                        VarDeclType.VAR -> null
+                        VarDeclType.CONST,
+                        VarDeclType.MEMORY -> (decl.value as NumericLiteral).number.toUInt()
+                    }
+                }
+                else null
+            } else null
+        }
+        else -> loadArg.substring(1).toUIntOrNull()
+    }
+}
+
+private fun optimizeIncDec(linesByFour: List<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 optimizeJsrRts(linesByFour: List<List<IndexedValue<String>>>): List<Modification> {
+    // jsr Sub + rts -> jmp Sub
+    val mods = mutableListOf<Modification>()
+    for (lines in linesByFour) {
+        val first = lines[0].value
+        val second = lines[1].value
+        if ((" jsr" in first || "\tjsr" in first ) && (" rts" in second || "\trts" in second)) {
+            mods += Modification(lines[0].index, false, lines[0].value.replace("jsr", "jmp"))
+            mods += Modification(lines[1].index, true, null)
+        }
+    }
+    return mods
+}

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

@@ -0,0 +1,61 @@
+package prog8.codegen.cpu6502
+
+import prog8.ast.expressions.ArrayIndexedExpression
+import prog8.ast.expressions.BuiltinFunctionCall
+import prog8.ast.expressions.Expression
+import prog8.ast.statements.Subroutine
+import prog8.code.core.Cx16VirtualRegisters
+import prog8.code.core.RegisterOrPair
+import prog8.code.core.RegisterOrStatusflag
+
+
+fun asmsub6502ArgsEvalOrder(sub: Subroutine): List<Int> {
+    val order = mutableListOf<Int>()
+    // order is:
+    //  1) cx16 virtual word registers,
+    //  2) paired CPU registers,
+    //  3) single CPU registers (X last), except A,
+    //  4) CPU Carry status flag
+    //  5) the A register itself last   (so everything before it can use the accumulator without having to save its value)
+    val args = sub.parameters.zip(sub.asmParameterRegisters).withIndex()
+    val (cx16regs, args2) = args.partition { it.value.second.registerOrPair in Cx16VirtualRegisters }
+    val pairedRegisters = arrayOf(RegisterOrPair.AX, RegisterOrPair.AY, RegisterOrPair.XY)
+    val (pairedRegs , args3) = args2.partition { it.value.second.registerOrPair in pairedRegisters }
+    val (regsWithoutA, args4) = args3.partition { it.value.second.registerOrPair != RegisterOrPair.A }
+    val (regA, rest) = args4.partition { it.value.second.registerOrPair != null }
+
+    cx16regs.forEach { order += it.index }
+    pairedRegs.forEach { order += it.index }
+    regsWithoutA.forEach {
+        if(it.value.second.registerOrPair != RegisterOrPair.X)
+            order += it.index
+    }
+    regsWithoutA.firstOrNull { it.value.second.registerOrPair==RegisterOrPair.X } ?.let { order += it.index}
+    rest.forEach { order += it.index }
+    regA.forEach { order += it.index }
+    require(order.size==sub.parameters.size)
+    return order
+}
+
+fun asmsub6502ArgsHaveRegisterClobberRisk(args: List<Expression>,
+                                                   paramRegisters: List<RegisterOrStatusflag>): Boolean {
+    fun isClobberRisk(expr: Expression): Boolean {
+        when (expr) {
+            is ArrayIndexedExpression -> {
+                return paramRegisters.any {
+                    it.registerOrPair in listOf(RegisterOrPair.Y, RegisterOrPair.AY, RegisterOrPair.XY)
+                }
+            }
+            is BuiltinFunctionCall -> {
+                if (expr.name == "lsb" || expr.name == "msb")
+                    return isClobberRisk(expr.args[0])
+                if (expr.name == "mkword")
+                    return isClobberRisk(expr.args[0]) && isClobberRisk(expr.args[1])
+                return !expr.isSimple
+            }
+            else -> return !expr.isSimple
+        }
+    }
+
+    return args.size>1 && args.any { isClobberRisk(it) }
+}

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

@@ -0,0 +1,147 @@
+package prog8.codegen.cpu6502
+
+import com.github.michaelbull.result.Ok
+import com.github.michaelbull.result.Result
+import com.github.michaelbull.result.mapError
+import prog8.code.core.*
+import prog8.code.core.SourceCode
+import java.io.File
+import java.nio.file.Path
+import kotlin.io.path.Path
+import kotlin.io.path.isRegularFile
+
+
+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(viceMonListName(name))
+    private val listFile = outputDir.resolve("$name.list")
+
+    override fun assemble(options: CompilationOptions): Boolean {
+
+        val assemblerCommand: List<String>
+
+        when (compTarget.name) {
+            in setOf("c64", "c128", "cx16") -> {
+                // CBM machines .prg generation.
+
+                // add "-Wlong-branch"  to see warnings about conversion of branch instructions to jumps (default = do this silently)
+                val command = mutableListOf("64tass", "--ascii", "--case-sensitive", "--long-branch",
+                    "-Wall", "-Wno-strict-bool", "-Wno-shadow", // "-Werror",
+                    "--dump-labels", "--vice-labels", "--labels=$viceMonListFile", "--no-monitor"
+                )
+
+                if(options.asmQuiet)
+                    command.add("--quiet")
+
+                if(options.asmListfile)
+                    command.add("--list=$listFile")
+
+                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 ${compTarget.name}.")
+                        binFile
+                    }
+                    else -> throw AssemblyError("invalid output type")
+                }
+                command.addAll(listOf("--output", outFile.toString(), assemblyFile.toString()))
+                assemblerCommand = command
+
+            }
+            "atari" -> {
+                // Atari800XL .xex generation.
+
+                // TODO are these options okay?
+                val command = mutableListOf("64tass", "--ascii", "--case-sensitive", "--long-branch",
+                    "-Wall", "-Wno-strict-bool", "-Wno-shadow", // "-Werror",
+                    "--no-monitor"
+                )
+
+                if(options.asmQuiet)
+                    command.add("--quiet")
+
+                if(options.asmListfile)
+                    command.add("--list=$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 ${compTarget.name}.")
+                        binFile
+                    }
+                    else -> throw AssemblyError("invalid output type")
+                }
+                command.addAll(listOf("--output", outFile.toString(), assemblyFile.toString()))
+                assemblerCommand = command
+            }
+            else -> throw AssemblyError("invalid compilation target")
+        }
+
+        val proc = ProcessBuilder(assemblerCommand).inheritIO().start()
+        val result = proc.waitFor()
+        if (result == 0 && compTarget.name!="atari") {
+            removeGeneratedLabelsFromMonlist()
+            generateBreakpointList()
+        }
+        return result==0
+    }
+
+    private fun removeGeneratedLabelsFromMonlist() {
+        val pattern = Regex("""al (\w+) \S+${generatedLabelPrefix}.+?""")
+        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, "; vice monitor breakpoint list now follows")
+        breakpoints.add(1, "; $num breakpoints have been defined")
+        breakpoints.add(2, "del")
+        viceMonListFile.toFile().appendText(breakpoints.joinToString("\n") + "\n")
+    }
+}
+
+
+internal fun loadAsmIncludeFile(filename: String, source: SourceCode): Result<String, NoSuchFileException> {
+    return if (filename.startsWith(SourceCode.libraryFilePrefix)) {
+        return com.github.michaelbull.result.runCatching {
+            SourceCode.Resource("/prog8lib/${filename.substring(SourceCode.libraryFilePrefix.length)}").text
+        }.mapError { NoSuchFileException(File(filename)) }
+    } else {
+        val sib = Path(source.origin).resolveSibling(filename)
+        if (sib.isRegularFile())
+            Ok(SourceCode.File(sib).text)
+        else
+            Ok(SourceCode.File(Path(filename)).text)
+    }
+}

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

@@ -1,32 +1,72 @@
-package prog8.compiler.target.cpu6502.codegen
+package prog8.codegen.cpu6502
 
 import prog8.ast.IFunctionCall
 import prog8.ast.Node
 import prog8.ast.Program
-import prog8.ast.base.*
 import prog8.ast.expressions.*
 import prog8.ast.statements.ArrayIndex
+import prog8.ast.statements.BuiltinFunctionCallStatement
 import prog8.ast.statements.DirectMemoryWrite
-import prog8.ast.statements.FunctionCallStatement
 import prog8.ast.statements.Subroutine
-import prog8.ast.toHex
-import prog8.compiler.target.AssemblyError
-import prog8.compiler.target.Cx16Target
-import prog8.compiler.target.cpu6502.codegen.assignment.*
-import prog8.compilerinterface.CpuType
-import prog8.compilerinterface.FSignature
-import prog8.compilerinterface.subroutineFloatEvalResultVar2
+import prog8.code.core.*
+import prog8.codegen.cpu6502.assignment.*
+import prog8.compiler.BuiltinFunctions
+import prog8.compiler.FSignature
+import prog8.compiler.builtinFunctionReturnType
 
-internal class BuiltinFunctionsAsmGen(private val program: Program, private val asmgen: AsmGen, private val assignAsmGen: AssignmentAsmGen) {
 
-    internal fun translateFunctioncallExpression(fcall: FunctionCall, func: FSignature, resultToStack: Boolean, resultRegister: RegisterOrPair?) {
+internal class BuiltinFunctionsAsmGen(private val program: Program,
+                                      private val asmgen: AsmGen,
+                                      private val assignAsmGen: AssignmentAsmGen,
+                                      private val allocations: VariableAllocator) {
+
+    internal fun translateFunctioncallExpression(fcall: BuiltinFunctionCall, resultToStack: Boolean, resultRegister: RegisterOrPair?) {
+        val func = BuiltinFunctions.getValue(fcall.target.nameInSource.single())
         translateFunctioncall(fcall, func, discardResult = false, resultToStack = resultToStack, resultRegister = resultRegister)
     }
 
-    internal fun translateFunctioncallStatement(fcall: FunctionCallStatement, func: FSignature) {
+    internal fun translateFunctioncallStatement(fcall: BuiltinFunctionCallStatement) {
+        val func = BuiltinFunctions.getValue(fcall.name)
         translateFunctioncall(fcall, func, discardResult = true, resultToStack = false, resultRegister = null)
     }
 
+    internal fun translateUnaryFunctioncall(name: String, singleArg: AsmAssignSource, isStatement: Boolean, scope: Subroutine): DataType {
+        val func = BuiltinFunctions.getValue(name)
+        val argExpression =
+            when(singleArg.kind) {
+                SourceStorageKind.LITERALNUMBER -> singleArg.number!!
+                SourceStorageKind.EXPRESSION -> singleArg.expression!!
+                SourceStorageKind.ARRAY -> singleArg.array!!
+                else -> {
+                    // TODO make it so that we can assign efficiently from something else as an expression....namely: register(s)
+                    //      this is useful in pipe expressions for instance, to skip the use of a temporary variable
+                    //      but for now, just assign it to a temporary variable and use that as a source
+                    //      Idea: to do this without having to rewrite every single function in translateFunctioncall(),
+                    //            hack a special IdentifierReference like "!6502.A/X/Y/AX/AY/XY" to reference a cpu register
+                    val tempvar = asmgen.getTempVarName(singleArg.datatype)
+                    val assignTempvar = AsmAssignment(
+                        singleArg,
+                        AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, singleArg.datatype, scope, variableAsmName = asmgen.asmVariableName(tempvar)),
+                        false, program.memsizer, Position.DUMMY
+                    )
+                    assignAsmGen.translateNormalAssignment(assignTempvar)
+                    // now use an expression to assign this tempvar
+                    val ident = IdentifierReference(tempvar, Position.DUMMY)
+                    ident.linkParents(scope)
+                    ident
+                }
+            }
+        val argExpressions = mutableListOf(argExpression);
+        val fcall = BuiltinFunctionCall(IdentifierReference(listOf(name), Position.DUMMY), argExpressions, Position.DUMMY)
+        fcall.linkParents(scope)
+        translateFunctioncall(fcall, func, discardResult = false, resultToStack = false, null)
+        return if(isStatement) {
+            DataType.UNDEFINED
+        } else {
+            builtinFunctionReturnType(func.name, argExpressions, program).getOrElse { throw AssemblyError("unknown dt") }
+        }
+    }
+
     private fun translateFunctioncall(fcall: IFunctionCall, func: FSignature, discardResult: Boolean, resultToStack: Boolean, resultRegister: RegisterOrPair?) {
         if (discardResult && func.pure)
             return  // can just ignore the whole function call altogether
@@ -46,7 +86,9 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
             "sum" -> funcSum(fcall, resultToStack, resultRegister, sscope)
             "any", "all" -> funcAnyAll(fcall, func, resultToStack, resultRegister, sscope)
             "sin8", "sin8u", "sin16", "sin16u",
-            "cos8", "cos8u", "cos16", "cos16u" -> funcSinCosInt(fcall, func, resultToStack, resultRegister, sscope)
+            "sinr8", "sinr8u", "sinr16", "sinr16u",
+            "cos8", "cos8u", "cos16", "cos16u",
+            "cosr8", "cosr8u", "cosr16", "cosr16u" -> funcSinCosInt(fcall, func, resultToStack, resultRegister, sscope)
             "sgn" -> funcSgn(fcall, func, resultToStack, resultRegister, sscope)
             "sin", "cos", "tan", "atan",
             "ln", "log2", "sqrt", "rad",
@@ -64,16 +106,87 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
             "peekw" -> funcPeekW(fcall, resultToStack, resultRegister)
             "peek" -> throw AssemblyError("peek() should have been replaced by @()")
             "pokew" -> funcPokeW(fcall)
+            "pokemon" -> { /* meme function */ }
             "poke" -> throw AssemblyError("poke() should have been replaced by @()")
+            "push" -> asmgen.pushCpuStack(DataType.UBYTE, fcall.args[0])
+            "pushw" -> asmgen.pushCpuStack(DataType.UWORD, fcall.args[0])
+            "pop" -> {
+                require(fcall.args[0] is IdentifierReference) {
+                    "attempt to pop a value into a differently typed variable, or in something else that isn't supported ${(fcall as Node).position}"
+                }
+                asmgen.popCpuStack(DataType.UBYTE, (fcall.args[0] as IdentifierReference).targetVarDecl(program)!!, (fcall as Node).definingSubroutine)
+            }
+            "popw" -> {
+                require(fcall.args[0] is IdentifierReference) {
+                    "attempt to pop a value into a differently typed variable, or in something else that isn't supported ${(fcall as Node).position}"
+                }
+                asmgen.popCpuStack(DataType.UWORD, (fcall.args[0] as IdentifierReference).targetVarDecl(program)!!, (fcall as Node).definingSubroutine)
+            }
+            "rsave" -> funcRsave()
+            "rsavex" -> funcRsaveX()
+            "rrestore" -> funcRrestore()
+            "rrestorex" -> funcRrestoreX()
             "cmp" -> funcCmp(fcall)
             "callfar" -> funcCallFar(fcall)
             "callrom" -> funcCallRom(fcall)
+            "syscall", "syscall1", "syscall2", "syscall3" -> throw AssemblyError("6502 assembly target doesn't use syscall function interface")
             else -> throw AssemblyError("missing asmgen for builtin func ${func.name}")
         }
     }
 
+    private fun funcRsave() {
+        if (asmgen.isTargetCpu(CpuType.CPU65c02))
+            asmgen.out("""
+                php
+                pha
+                phy
+                phx""")
+        else
+            // see http://6502.org/tutorials/register_preservation.html
+            asmgen.out("""
+                php
+                sta  P8ZP_SCRATCH_REG
+                pha
+                txa
+                pha
+                tya
+                pha
+                lda  P8ZP_SCRATCH_REG""")
+    }
+
+    private fun funcRsaveX() {
+        if (asmgen.isTargetCpu(CpuType.CPU65c02))
+            asmgen.out("  phx")
+        else
+            asmgen.out("  txa |  pha")
+    }
+
+    private fun funcRrestore() {
+        if (asmgen.isTargetCpu(CpuType.CPU65c02))
+            asmgen.out("""
+                plx
+                ply
+                pla
+                plp""")
+        else
+            asmgen.out("""
+                pla
+                tay
+                pla
+                tax
+                pla
+                plp""")
+    }
+
+    private fun funcRrestoreX() {
+        if (asmgen.isTargetCpu(CpuType.CPU65c02))
+            asmgen.out("  plx")
+        else
+            asmgen.out("  sta  P8ZP_SCRATCH_B1 |  pla |  tax |  lda  P8ZP_SCRATCH_B1")
+    }
+
     private fun funcCallFar(fcall: IFunctionCall) {
-        if(asmgen.options.compTarget !is Cx16Target)
+        if(asmgen.options.compTarget.name != "cx16")
             throw AssemblyError("callfar only works on cx16 target at this time")
 
         val bank = fcall.args[0].constValue(program)?.number?.toInt()
@@ -87,7 +200,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
             throw AssemblyError("callfar done on bank 0 which is reserved for the kernal")
 
         val argAddrArg = fcall.args[2]
-        if(argAddrArg.constValue(program)?.number == 0) {
+        if(argAddrArg.constValue(program)?.number == 0.0) {
             asmgen.out("""
                 jsr  cx16.jsrfar
                 .word  ${address.toHex()}
@@ -104,7 +217,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                         .byte  ${bank.toHex()}
                         sta  ${asmgen.asmVariableName(argAddrArg.identifier)}""")
                 }
-                is NumericLiteralValue -> {
+                is NumericLiteral -> {
                     asmgen.out("""
                         lda  ${argAddrArg.number.toHex()}
                         jsr  cx16.jsrfar
@@ -118,7 +231,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
     }
 
     private fun funcCallRom(fcall: IFunctionCall) {
-        if(asmgen.options.compTarget !is Cx16Target)
+        if(asmgen.options.compTarget.name != "cx16")
             throw AssemblyError("callrom only works on cx16 target at this time")
 
         val bank = fcall.args[0].constValue(program)?.number?.toInt()
@@ -132,7 +245,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
             throw AssemblyError("callrom bank must be <32")
 
         val argAddrArg = fcall.args[2]
-        if(argAddrArg.constValue(program)?.number == 0) {
+        if(argAddrArg.constValue(program)?.number == 0.0) {
             asmgen.out("""
                 lda  $01
                 pha
@@ -157,7 +270,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                         pla
                         sta  $01""")
                 }
-                is NumericLiteralValue -> {
+                is NumericLiteral -> {
                     asmgen.out("""
                         lda  $01
                         pha
@@ -177,8 +290,8 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
     private fun funcCmp(fcall: IFunctionCall) {
         val arg1 = fcall.args[0]
         val arg2 = fcall.args[1]
-        val dt1 = arg1.inferType(program).getOr(DataType.UNDEFINED)
-        val dt2 = arg2.inferType(program).getOr(DataType.UNDEFINED)
+        val dt1 = arg1.inferType(program).getOrElse { throw AssemblyError("unknown dt") }
+        val dt2 = arg2.inferType(program).getOrElse { throw AssemblyError("unknown dt") }
         if(dt1 in ByteDatatypes) {
             if(dt2 in ByteDatatypes) {
                 when (arg2) {
@@ -186,12 +299,12 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                         asmgen.assignExpressionToRegister(arg1, RegisterOrPair.A)
                         asmgen.out("  cmp  ${asmgen.asmVariableName(arg2)}")
                     }
-                    is NumericLiteralValue -> {
+                    is NumericLiteral -> {
                         asmgen.assignExpressionToRegister(arg1, RegisterOrPair.A)
-                        asmgen.out("  cmp  #${arg2.number}")
+                        asmgen.out("  cmp  #${arg2.number.toInt()}")
                     }
                     is DirectMemoryRead -> {
-                        if(arg2.addressExpression is NumericLiteralValue) {
+                        if(arg2.addressExpression is NumericLiteral) {
                             asmgen.assignExpressionToRegister(arg1, RegisterOrPair.A)
                             asmgen.out("  cmp  ${arg2.addressExpression.constValue(program)!!.number.toHex()}")
                         } else {
@@ -220,12 +333,12 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                             cmp  ${asmgen.asmVariableName(arg2)}
 +""")
                     }
-                    is NumericLiteralValue -> {
+                    is NumericLiteral -> {
                         asmgen.assignExpressionToRegister(arg1, RegisterOrPair.AY)
                         asmgen.out("""
-                            cpy  #>${arg2.number}
+                            cpy  #>${arg2.number.toInt()}
                             bne  +
-                            cmp  #<${arg2.number}
+                            cmp  #<${arg2.number.toInt()}
 +""")
                     }
                     else -> {
@@ -244,15 +357,16 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
     }
 
     private fun funcMemory(fcall: IFunctionCall, discardResult: Boolean, resultToStack: Boolean, resultRegister: RegisterOrPair?) {
-        if(discardResult || fcall !is FunctionCall)
+        if(discardResult || fcall !is BuiltinFunctionCall)
             throw AssemblyError("should not discard result of memory allocation at $fcall")
-        val nameRef = fcall.args[0] as IdentifierReference
-        val name = (nameRef.targetVarDecl(program)!!.value as StringLiteralValue).value
-        val size = (fcall.args[1] as NumericLiteralValue).number.toInt()
+        val name = (fcall.args[0] as StringLiteral).value
+        require(name.all { it.isLetterOrDigit() || it=='_' }) {"memory name should be a valid symbol name"}
+        val size = (fcall.args[1] as NumericLiteral).number.toUInt()
+        val align = (fcall.args[2] as NumericLiteral).number.toUInt()
 
-        val existingSize = asmgen.slabs[name]
-        if(existingSize!=null && existingSize!=size)
-            throw AssemblyError("memory slab '$name' already exists with a different size ($size) at ${fcall.position}")
+        val existing = allocations.getMemorySlab(name)
+        if(existing!=null && (existing.first!=size || existing.second!=align))
+            throw AssemblyError("memory slab '$name' already exists with a different size or alignment at ${fcall.position}")
 
         val slabname = IdentifierReference(listOf("prog8_slabs", name), fcall.position)
         slabname.linkParents(fcall)
@@ -264,7 +378,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                 AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.AY, false, null, program, asmgen)
         val assign = AsmAssignment(src, target, false, program.memsizer, fcall.position)
         asmgen.translateNormalAssignment(assign)
-        asmgen.slabs[name] = size
+        allocations.allocateMemorySlab(name, size, align)
     }
 
     private fun funcSqrt16(fcall: IFunctionCall, func: FSignature, resultToStack: Boolean, resultRegister: RegisterOrPair?, scope: Subroutine?) {
@@ -283,11 +397,11 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
             asmgen.out("  jsr  prog8_lib.func_${func.name}_stack")
         else
             when(func.name) {
-                "sin8", "sin8u", "cos8", "cos8u" -> {
+                "sin8", "sin8u", "sinr8", "sinr8u", "cos8", "cos8u", "cosr8", "cosr8u" -> {
                     asmgen.out("  jsr  prog8_lib.func_${func.name}_into_A")
                     assignAsmGen.assignRegisterByte(AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.A, false, scope, program, asmgen), CpuRegister.A)
                 }
-                "sin16", "sin16u", "cos16", "cos16u" -> {
+                "sin16", "sin16u", "sinr16", "sinr16u", "cos16", "cos16u", "cosr16", "cosr16u" -> {
                     asmgen.out("  jsr  prog8_lib.func_${func.name}_into_AY")
                     assignAsmGen.assignRegisterpairWord(AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.AY, false, scope, program, asmgen), RegisterOrPair.AY)
                 }
@@ -376,8 +490,8 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                         asmgen.out("  jsr  prog8_lib.ror2_array_ub")
                     }
                     is DirectMemoryRead -> {
-                        if (what.addressExpression is NumericLiteralValue) {
-                            val number = (what.addressExpression as NumericLiteralValue).number
+                        if (what.addressExpression is NumericLiteral) {
+                            val number = (what.addressExpression as NumericLiteral).number
                             asmgen.out("  lda  ${number.toHex()} |  lsr  a |  bcc  + |  ora  #\$80 |+  |  sta  ${number.toHex()}")
                         } else {
                             asmgen.assignExpressionToRegister(what.addressExpression, RegisterOrPair.AY)
@@ -419,14 +533,14 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                         asmgen.out("  jsr  prog8_lib.ror_array_ub")
                     }
                     is DirectMemoryRead -> {
-                        if (what.addressExpression is NumericLiteralValue) {
-                            val number = (what.addressExpression as NumericLiteralValue).number
+                        if (what.addressExpression is NumericLiteral) {
+                            val number = (what.addressExpression as NumericLiteral).number
                             asmgen.out("  ror  ${number.toHex()}")
                         } else {
                             val ptrAndIndex = asmgen.pointerViaIndexRegisterPossible(what.addressExpression)
                             if(ptrAndIndex!=null) {
                                 asmgen.assignExpressionToRegister(ptrAndIndex.second, RegisterOrPair.X)
-                                asmgen.saveRegisterLocal(CpuRegister.X, (fcall as FunctionCallStatement).definingSubroutine!!)
+                                asmgen.saveRegisterLocal(CpuRegister.X, (fcall as Node).definingSubroutine!!)
                                 asmgen.assignExpressionToRegister(ptrAndIndex.first, RegisterOrPair.AY)
                                 asmgen.restoreRegisterLocal(CpuRegister.X)
                                 asmgen.out("""
@@ -477,8 +591,8 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                         asmgen.out("  jsr  prog8_lib.rol2_array_ub")
                     }
                     is DirectMemoryRead -> {
-                        if (what.addressExpression is NumericLiteralValue) {
-                            val number = (what.addressExpression as NumericLiteralValue).number
+                        if (what.addressExpression is NumericLiteral) {
+                            val number = (what.addressExpression as NumericLiteral).number
                             asmgen.out("  lda  ${number.toHex()} |  cmp  #\$80 |  rol  a |  sta  ${number.toHex()}")
                         } else {
                             asmgen.assignExpressionToRegister(what.addressExpression, RegisterOrPair.AY)
@@ -520,14 +634,14 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                         asmgen.out("  jsr  prog8_lib.rol_array_ub")
                     }
                     is DirectMemoryRead -> {
-                        if (what.addressExpression is NumericLiteralValue) {
-                            val number = (what.addressExpression as NumericLiteralValue).number
+                        if (what.addressExpression is NumericLiteral) {
+                            val number = (what.addressExpression as NumericLiteral).number
                             asmgen.out("  rol  ${number.toHex()}")
                         } else {
                             val ptrAndIndex = asmgen.pointerViaIndexRegisterPossible(what.addressExpression)
                             if(ptrAndIndex!=null) {
                                 asmgen.assignExpressionToRegister(ptrAndIndex.second, RegisterOrPair.X)
-                                asmgen.saveRegisterLocal(CpuRegister.X, (fcall as FunctionCallStatement).definingSubroutine!!)
+                                asmgen.saveRegisterLocal(CpuRegister.X, (fcall as Node).definingSubroutine!!)
                                 asmgen.assignExpressionToRegister(ptrAndIndex.first, RegisterOrPair.AY)
                                 asmgen.restoreRegisterLocal(CpuRegister.X)
                                 asmgen.out("""
@@ -750,8 +864,8 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
 
         // optimized simple case: swap two memory locations
         if(first is DirectMemoryRead && second is DirectMemoryRead) {
-            val addr1 = (first.addressExpression as? NumericLiteralValue)?.number?.toHex()
-            val addr2 = (second.addressExpression as? NumericLiteralValue)?.number?.toHex()
+            val addr1 = (first.addressExpression as? NumericLiteral)?.number?.toHex()
+            val addr2 = (second.addressExpression as? NumericLiteral)?.number?.toHex()
             val name1 = if(first.addressExpression is IdentifierReference) asmgen.asmVariableName(first.addressExpression as IdentifierReference) else null
             val name2 = if(second.addressExpression is IdentifierReference) asmgen.asmVariableName(second.addressExpression as IdentifierReference) else null
 
@@ -782,10 +896,10 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                         if(pointerVariable != null
                             && pointerVariable isSameAs secondExpr.left
                             && firstExpr.operator == "+" && secondExpr.operator == "+"
-                            && (firstOffset is NumericLiteralValue || firstOffset is IdentifierReference || firstOffset is TypecastExpression)
-                            && (secondOffset is NumericLiteralValue || secondOffset is IdentifierReference || secondOffset is TypecastExpression)
+                            && (firstOffset is NumericLiteral || firstOffset is IdentifierReference || firstOffset is TypecastExpression)
+                            && (secondOffset is NumericLiteral || secondOffset is IdentifierReference || secondOffset is TypecastExpression)
                         ) {
-                            if(firstOffset is NumericLiteralValue && secondOffset is NumericLiteralValue) {
+                            if(firstOffset is NumericLiteral && secondOffset is NumericLiteral) {
                                 if(firstOffset!=secondOffset) {
                                     swapArrayValues(
                                         DataType.UBYTE,
@@ -822,13 +936,11 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
             val arrayVarName1 = asmgen.asmVariableName(first.arrayvar)
             val arrayVarName2 = asmgen.asmVariableName(second.arrayvar)
             val elementIDt = first.inferType(program)
-            if(!elementIDt.isKnown)
-                throw AssemblyError("unknown dt")
-            val elementDt = elementIDt.getOr(DataType.UNDEFINED)
+            val elementDt = elementIDt.getOrElse { throw AssemblyError("unknown dt") }
 
-            val firstNum = first.indexer.indexExpr as? NumericLiteralValue
+            val firstNum = first.indexer.indexExpr as? NumericLiteral
             val firstVar = first.indexer.indexExpr as? IdentifierReference
-            val secondNum = second.indexer.indexExpr as? NumericLiteralValue
+            val secondNum = second.indexer.indexExpr as? NumericLiteral
             val secondVar = second.indexer.indexExpr as? IdentifierReference
 
             if(firstNum!=null && secondNum!=null) {
@@ -897,7 +1009,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
         }
     }
 
-    private fun swapArrayValues(elementDt: DataType, arrayVarName1: String, indexValue1: NumericLiteralValue, arrayVarName2: String, indexValue2: NumericLiteralValue) {
+    private fun swapArrayValues(elementDt: DataType, arrayVarName1: String, indexValue1: NumericLiteral, arrayVarName2: String, indexValue2: NumericLiteral) {
         val index1 = indexValue1.number.toInt() * program.memsizer.memorySize(elementDt)
         val index2 = indexValue2.number.toInt() * program.memsizer.memorySize(elementDt)
         when(elementDt) {
@@ -1011,7 +1123,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
         }
     }
 
-    private fun swapArrayValues(elementDt: DataType, arrayVarName1: String, indexValue1: NumericLiteralValue, arrayVarName2: String, indexName2: IdentifierReference) {
+    private fun swapArrayValues(elementDt: DataType, arrayVarName1: String, indexValue1: NumericLiteral, arrayVarName2: String, indexName2: IdentifierReference) {
         val index1 = indexValue1.number.toInt() * program.memsizer.memorySize(elementDt)
         val idxAsmName2 = asmgen.asmVariableName(indexName2)
         when(elementDt) {
@@ -1069,7 +1181,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
         }
     }
 
-    private fun swapArrayValues(elementDt: DataType, arrayVarName1: String, indexName1: IdentifierReference, arrayVarName2: String, indexValue2: NumericLiteralValue) {
+    private fun swapArrayValues(elementDt: DataType, arrayVarName1: String, indexName1: IdentifierReference, arrayVarName2: String, indexValue2: NumericLiteral) {
         val idxAsmName1 = asmgen.asmVariableName(indexName1)
         val index2 = indexValue2.number.toInt() * program.memsizer.memorySize(elementDt)
         when(elementDt) {
@@ -1180,7 +1292,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
 
     private fun funcPokeW(fcall: IFunctionCall) {
         when(val addrExpr = fcall.args[0]) {
-            is NumericLiteralValue -> {
+            is NumericLiteral -> {
                 asmgen.assignExpressionToRegister(fcall.args[1], RegisterOrPair.AY)
                 val addr = addrExpr.number.toHex()
                 asmgen.out("  sta  $addr |  sty  ${addr}+1")
@@ -1211,13 +1323,13 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                 }
             }
             is BinaryExpression -> {
-                if(addrExpr.operator=="+" && addrExpr.left is IdentifierReference && addrExpr.right is NumericLiteralValue) {
+                if(addrExpr.operator=="+" && addrExpr.left is IdentifierReference && addrExpr.right is NumericLiteral) {
                     val varname = asmgen.asmVariableName(addrExpr.left as IdentifierReference)
                     if(asmgen.isZpVar(addrExpr.left as IdentifierReference)) {
                         // pointervar is already in the zero page, no need to copy
                         asmgen.saveRegisterLocal(CpuRegister.X, (fcall as Node).definingSubroutine!!)
                         asmgen.assignExpressionToRegister(fcall.args[1], RegisterOrPair.AX)
-                        val index = (addrExpr.right as NumericLiteralValue).number.toHex()
+                        val index = (addrExpr.right as NumericLiteral).number.toHex()
                         asmgen.out("""
                             ldy  #$index
                             sta  ($varname),y
@@ -1229,6 +1341,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                     }
                 }
             }
+            else -> throw AssemblyError("wrong pokew arg type")
         }
 
         asmgen.assignExpressionToVariable(fcall.args[0], "P8ZP_SCRATCH_W1", DataType.UWORD, null)
@@ -1238,7 +1351,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
 
     private fun funcPeekW(fcall: IFunctionCall, resultToStack: Boolean, resultRegister: RegisterOrPair?) {
         when(val addrExpr = fcall.args[0]) {
-            is NumericLiteralValue -> {
+            is NumericLiteral -> {
                 val addr = addrExpr.number.toHex()
                 asmgen.out("  lda  $addr |  ldy  ${addr}+1")
             }
@@ -1268,11 +1381,11 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                 }
             }
             is BinaryExpression -> {
-                if(addrExpr.operator=="+" && addrExpr.left is IdentifierReference && addrExpr.right is NumericLiteralValue) {
+                if(addrExpr.operator=="+" && addrExpr.left is IdentifierReference && addrExpr.right is NumericLiteral) {
                     val varname = asmgen.asmVariableName(addrExpr.left as IdentifierReference)
                     if(asmgen.isZpVar(addrExpr.left as IdentifierReference)) {
                         // pointervar is already in the zero page, no need to copy
-                        val index = (addrExpr.right as NumericLiteralValue).number.toHex()
+                        val index = (addrExpr.right as NumericLiteral).number.toHex()
                         asmgen.out("""
                             ldy  #$index
                             lda  ($varname),y
@@ -1319,14 +1432,14 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
             asmgen.out("  sta  P8ESTACK_LO,x |  tya |  sta  P8ESTACK_HI,x |  dex")
         } else {
             val reg = resultRegister ?: RegisterOrPair.AY
-            var needAsave = !(fcall.args[0] is DirectMemoryRead || fcall.args[0] is NumericLiteralValue || fcall.args[0] is IdentifierReference)
+            var needAsave = !(fcall.args[0] is DirectMemoryRead || fcall.args[0] is NumericLiteral || fcall.args[0] is IdentifierReference)
             if(!needAsave) {
                 val mr0 = fcall.args[0] as? DirectMemoryRead
                 val mr1 = fcall.args[1] as? DirectMemoryRead
                 if (mr0 != null)
-                    needAsave = mr0.addressExpression !is NumericLiteralValue && mr0.addressExpression !is IdentifierReference
+                    needAsave = mr0.addressExpression !is NumericLiteral && mr0.addressExpression !is IdentifierReference
                 if (mr1 != null)
-                    needAsave = needAsave or (mr1.addressExpression !is NumericLiteralValue && mr1.addressExpression !is IdentifierReference)
+                    needAsave = needAsave or (mr1.addressExpression !is NumericLiteral && mr1.addressExpression !is IdentifierReference)
             }
             when(reg) {
                 RegisterOrPair.AX -> {
@@ -1369,7 +1482,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
         val arg = fcall.args.single()
         if (!arg.inferType(program).isWords)
             throw AssemblyError("msb required word argument")
-        if (arg is NumericLiteralValue)
+        if (arg is NumericLiteral)
             throw AssemblyError("msb(const) should have been const-folded away")
         if (arg is IdentifierReference) {
             val sourceName = asmgen.asmVariableName(arg)
@@ -1380,6 +1493,16 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                     null, RegisterOrPair.A -> asmgen.out("  lda  $sourceName+1")
                     RegisterOrPair.X -> asmgen.out("  ldx  $sourceName+1")
                     RegisterOrPair.Y -> asmgen.out("  ldy  $sourceName+1")
+                    RegisterOrPair.AX -> asmgen.out("  lda  $sourceName+1 |  ldx  #0")
+                    RegisterOrPair.AY -> asmgen.out("  lda  $sourceName+1 |  ldy  #0")
+                    RegisterOrPair.XY -> asmgen.out("  ldx  $sourceName+1 |  ldy  #0")
+                    in Cx16VirtualRegisters -> {
+                        val regname = resultRegister.name.lowercase()
+                        if(asmgen.isTargetCpu(CpuType.CPU65c02))
+                            asmgen.out("  lda  $sourceName+1 |  sta  cx16.$regname |  stz  cx16.$regname+1")
+                        else
+                            asmgen.out("  lda  $sourceName+1 |  sta  cx16.$regname |  lda  #0 |  sta  cx16.$regname+1")
+                    }
                     else -> throw AssemblyError("invalid reg")
                 }
             }
@@ -1413,7 +1536,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
         val arg = fcall.args.single()
         if (!arg.inferType(program).isWords)
             throw AssemblyError("lsb required word argument")
-        if (arg is NumericLiteralValue)
+        if (arg is NumericLiteral)
             throw AssemblyError("lsb(const) should have been const-folded away")
 
         if (arg is IdentifierReference) {
@@ -1425,6 +1548,16 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                     null, RegisterOrPair.A -> asmgen.out("  lda  $sourceName")
                     RegisterOrPair.X -> asmgen.out("  ldx  $sourceName")
                     RegisterOrPair.Y -> asmgen.out("  ldy  $sourceName")
+                    RegisterOrPair.AX -> asmgen.out("  lda  $sourceName |  ldx  #0")
+                    RegisterOrPair.AY -> asmgen.out("  lda  $sourceName |  ldy  #0")
+                    RegisterOrPair.XY -> asmgen.out("  ldx  $sourceName |  ldy  #0")
+                    in Cx16VirtualRegisters -> {
+                        val regname = resultRegister.name.lowercase()
+                        if(asmgen.isTargetCpu(CpuType.CPU65c02))
+                            asmgen.out("  lda  $sourceName |  sta  cx16.$regname |  stz  cx16.$regname+1")
+                        else
+                            asmgen.out("  lda  $sourceName |  sta  cx16.$regname |  lda  #0 |  sta  cx16.$regname+1")
+                    }
                     else -> throw AssemblyError("invalid reg")
                 }
             }
@@ -1475,7 +1608,9 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
     }
 
     private fun translateArguments(args: MutableList<Expression>, signature: FSignature, scope: Subroutine?) {
-        val callConv = signature.callConvention(args.map { it.inferType(program).getOr(DataType.UNDEFINED) })
+        val callConv = signature.callConvention(args.map {
+            it.inferType(program).getOrElse { throw AssemblyError("unknown dt") }
+        })
 
         fun getSourceForFloat(value: Expression): AsmAssignSource {
             return when (value) {
@@ -1483,14 +1618,14 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                     val addr = AddressOf(value, value.position)
                     AsmAssignSource.fromAstSource(addr, program, asmgen)
                 }
-                is NumericLiteralValue -> {
+                is NumericLiteral -> {
                     throw AssemblyError("float literals should have been converted into autovar")
                 }
                 else -> {
                     if(scope==null)
                         throw AssemblyError("cannot use float arguments outside of a subroutine scope")
 
-                    scope.asmGenInfo.usedFloatEvalResultVar2 = true
+                    asmgen.subroutineExtra(scope).usedFloatEvalResultVar2 = true
                     val variable = IdentifierReference(listOf(subroutineFloatEvalResultVar2), value.position)
                     val addr = AddressOf(variable, value.position)
                     addr.linkParents(value)

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

@@ -0,0 +1,862 @@
+package prog8.codegen.cpu6502
+
+import prog8.ast.Program
+import prog8.ast.expressions.*
+import prog8.code.core.*
+import kotlin.math.absoluteValue
+
+internal class ExpressionsAsmGen(private val program: Program,
+                                 private val asmgen: AsmGen,
+                                 private val allocator: VariableAllocator) {
+
+    @Deprecated("avoid calling this as it generates slow evalstack based code")
+    internal fun translateExpression(expression:Expression) {
+        if (this.asmgen.options.slowCodegenWarnings) {
+            asmgen.errors.warn("slow stack evaluation used for expression $expression", expression.position)
+        }
+        translateExpressionInternal(expression)
+    }
+
+
+    // the rest of the methods are all PRIVATE
+
+
+    private fun translateExpressionInternal(expression: Expression) {
+
+        when(expression) {
+            is PrefixExpression -> translateExpression(expression)
+            is BinaryExpression -> translateExpression(expression)
+            is ArrayIndexedExpression -> translateExpression(expression)
+            is TypecastExpression -> translateExpression(expression)
+            is AddressOf -> translateExpression(expression)
+            is DirectMemoryRead -> asmgen.translateDirectMemReadExpressionToRegAorStack(expression, true)
+            is NumericLiteral -> translateExpression(expression)
+            is IdentifierReference -> translateExpression(expression)
+            is FunctionCallExpression -> translateFunctionCallResultOntoStack(expression)
+            is BuiltinFunctionCall -> asmgen.translateBuiltinFunctionCallExpression(expression, true, null)
+            is PipeExpression -> asmgen.translatePipeExpression(expression.source, expression.segments,
+                                                                expression, isStatement = false, pushResultOnEstack = true )
+            is ContainmentCheck -> throw AssemblyError("containment check as complex expression value is not supported")
+            is ArrayLiteral, is StringLiteral -> throw AssemblyError("no asm gen for string/array literal value assignment - should have been replaced by a variable")
+            is RangeExpression -> throw AssemblyError("range expression should have been changed into array values")
+            is CharLiteral -> throw AssemblyError("charliteral should have been replaced by ubyte using certain encoding")
+            else -> TODO("missing expression asmgen for $expression")
+        }
+    }
+
+    private fun translateFunctionCallResultOntoStack(call: FunctionCallExpression) {
+        // only for use in nested expression evaluation
+
+        val sub = call.target.targetSubroutine(program)!!
+        asmgen.saveXbeforeCall(call)
+        asmgen.translateFunctionCall(call, true)
+        if(sub.regXasResult()) {
+            // store the return value in X somewhere that we can access again below
+            asmgen.out("  stx  P8ZP_SCRATCH_REG")
+        }
+        asmgen.restoreXafterCall(call)
+
+        val returns = sub.returntypes.zip(sub.asmReturnvaluesRegisters)
+        for ((_, reg) in returns) {
+            // result value is in cpu or status registers, put it on the stack instead (as we're evaluating an expression tree)
+            if (reg.registerOrPair != null) {
+                when (reg.registerOrPair!!) {
+                    RegisterOrPair.A -> asmgen.out("  sta  P8ESTACK_LO,x |  dex")
+                    RegisterOrPair.Y -> asmgen.out("  tya |  sta  P8ESTACK_LO,x |  dex")
+                    RegisterOrPair.AY -> asmgen.out("  sta  P8ESTACK_LO,x |  tya |  sta  P8ESTACK_HI,x |  dex")
+                    RegisterOrPair.X -> asmgen.out("  lda  P8ZP_SCRATCH_REG |  sta  P8ESTACK_LO,x |  dex")
+                    RegisterOrPair.AX -> asmgen.out("  sta  P8ESTACK_LO,x |  lda  P8ZP_SCRATCH_REG |  sta  P8ESTACK_HI,x |  dex")
+                    RegisterOrPair.XY -> asmgen.out("  tya |  sta  P8ESTACK_HI,x |  lda  P8ZP_SCRATCH_REG |  sta  P8ESTACK_LO,x |  dex")
+                    RegisterOrPair.FAC1 -> asmgen.out("  jsr  floats.push_fac1")
+                    RegisterOrPair.FAC2 -> asmgen.out("  jsr  floats.push_fac2")
+                    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 -> {
+                        asmgen.out(
+                            """
+                            lda  cx16.${reg.registerOrPair.toString().lowercase()}
+                            sta  P8ESTACK_LO,x
+                            lda  cx16.${reg.registerOrPair.toString().lowercase()}+1
+                            sta  P8ESTACK_HI,x
+                            dex
+                        """)
+                    }
+                }
+            } else when(reg.statusflag) {
+                Statusflag.Pc -> {
+                    asmgen.out("""
+                        lda  #0
+                        rol  a
+                        sta  P8ESTACK_LO,x
+                        dex""")
+                }
+                Statusflag.Pz -> {
+                    asmgen.out("""
+                        beq  +
+                        lda  #0
+                        beq  ++
++                           lda  #1
++                           sta  P8ESTACK_LO,x
+                        dex""")
+                }
+                Statusflag.Pv -> {
+                    asmgen.out("""
+                        bvs  +
+                        lda  #0
+                        beq  ++
++                           lda  #1
++                           sta  P8ESTACK_LO,x
+                        dex""")
+                }
+                Statusflag.Pn -> {
+                    asmgen.out("""
+                        bmi  +
+                        lda  #0
+                        beq  ++
++                           lda  #1
++                           sta  P8ESTACK_LO,x
+                        dex""")
+                }
+                null -> {}
+            }
+        }
+    }
+
+    private fun translateExpression(typecast: TypecastExpression) {
+        translateExpressionInternal(typecast.expression)
+        when(typecast.expression.inferType(program).getOr(DataType.UNDEFINED)) {
+            DataType.UBYTE -> {
+                when(typecast.type) {
+                    DataType.UBYTE, DataType.BYTE -> {}
+                    DataType.UWORD, DataType.WORD -> {
+                        if(asmgen.isTargetCpu(CpuType.CPU65c02))
+                            asmgen.out("  stz  P8ESTACK_HI+1,x")
+                        else
+                            asmgen.out("  lda  #0  |  sta  P8ESTACK_HI+1,x")
+                    }
+                    DataType.FLOAT -> asmgen.out(" jsr  floats.stack_ub2float")
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            DataType.BYTE -> {
+                when(typecast.type) {
+                    DataType.UBYTE, DataType.BYTE -> {}
+                    DataType.UWORD, DataType.WORD -> asmgen.signExtendStackLsb(DataType.BYTE)
+                    DataType.FLOAT -> asmgen.out(" jsr  floats.stack_b2float")
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            DataType.UWORD -> {
+                when(typecast.type) {
+                    DataType.BYTE, DataType.UBYTE -> {}
+                    DataType.WORD, DataType.UWORD -> {}
+                    DataType.FLOAT -> asmgen.out(" jsr  floats.stack_uw2float")
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            DataType.WORD -> {
+                when(typecast.type) {
+                    DataType.BYTE, DataType.UBYTE -> {}
+                    DataType.WORD, DataType.UWORD -> {}
+                    DataType.FLOAT -> asmgen.out(" jsr  floats.stack_w2float")
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            DataType.FLOAT -> {
+                when(typecast.type) {
+                    DataType.UBYTE -> asmgen.out(" jsr  floats.stack_float2uw")
+                    DataType.BYTE -> asmgen.out(" jsr  floats.stack_float2w")
+                    DataType.UWORD -> asmgen.out(" jsr  floats.stack_float2uw")
+                    DataType.WORD -> asmgen.out(" jsr  floats.stack_float2w")
+                    DataType.FLOAT -> {}
+                    in PassByReferenceDatatypes -> throw AssemblyError("cannot cast to a pass-by-reference datatype")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            DataType.STR -> {
+                if (typecast.type != DataType.UWORD && typecast.type == DataType.STR)
+                    throw AssemblyError("cannot typecast a string into another incompatitble type")
+            }
+            in PassByReferenceDatatypes -> throw AssemblyError("cannot cast pass-by-reference value into another type")
+            else -> throw AssemblyError("weird type")
+        }
+    }
+
+    private fun translateExpression(expr: AddressOf) {
+        val name = asmgen.asmVariableName(expr.identifier)
+        asmgen.out("  lda  #<$name |  sta  P8ESTACK_LO,x |  lda  #>$name  |  sta  P8ESTACK_HI,x  | dex")
+    }
+
+    private fun translateExpression(expr: NumericLiteral) {
+        when(expr.type) {
+            DataType.UBYTE, DataType.BYTE -> asmgen.out(" lda  #${expr.number.toHex()}  | sta  P8ESTACK_LO,x  | dex")
+            DataType.UWORD, DataType.WORD -> asmgen.out("""
+                lda  #<${expr.number.toHex()}
+                sta  P8ESTACK_LO,x
+                lda  #>${expr.number.toHex()}
+                sta  P8ESTACK_HI,x
+                dex
+            """)
+            DataType.FLOAT -> {
+                val floatConst = allocator.getFloatAsmConst(expr.number)
+                asmgen.out(" lda  #<$floatConst |  ldy  #>$floatConst |  jsr  floats.push_float")
+            }
+            else -> throw AssemblyError("weird type")
+        }
+    }
+
+    private fun translateExpression(expr: IdentifierReference) {
+        val varname = asmgen.asmVariableName(expr)
+        when(expr.inferType(program).getOr(DataType.UNDEFINED)) {
+            DataType.UBYTE, DataType.BYTE -> {
+                asmgen.out("  lda  $varname  |  sta  P8ESTACK_LO,x  |  dex")
+            }
+            DataType.UWORD, DataType.WORD -> {
+                asmgen.out("  lda  $varname  |  sta  P8ESTACK_LO,x  |  lda  $varname+1 |  sta  P8ESTACK_HI,x |  dex")
+            }
+            DataType.FLOAT -> {
+                asmgen.out(" lda  #<$varname |  ldy  #>$varname|  jsr  floats.push_float")
+            }
+            in IterableDatatypes -> {
+                asmgen.out("  lda  #<$varname  |  sta  P8ESTACK_LO,x  |  lda  #>$varname |  sta  P8ESTACK_HI,x |  dex")
+            }
+            else -> throw AssemblyError("stack push weird variable type $expr")
+        }
+    }
+
+    private fun translateExpression(expr: BinaryExpression) {
+        // Uses evalstack to evaluate the given expression.
+        // TODO we're slowly reducing the number of places where this is called and instead replace that by more efficient assignment-form code (using temp var or register for instance).
+        val leftIDt = expr.left.inferType(program)
+        val rightIDt = expr.right.inferType(program)
+        if(!leftIDt.isKnown || !rightIDt.isKnown)
+            throw AssemblyError("can't infer type of both expression operands")
+
+        val leftDt = leftIDt.getOrElse { throw AssemblyError("unknown dt") }
+        val rightDt = rightIDt.getOrElse { throw AssemblyError("unknown dt") }
+        // see if we can apply some optimized routines
+        when(expr.operator) {
+            "+" -> {
+                if(leftDt in IntegerDatatypes && rightDt in IntegerDatatypes) {
+                    val leftVal = expr.left.constValue(program)?.number?.toInt()
+                    val rightVal = expr.right.constValue(program)?.number?.toInt()
+                    if (leftVal!=null && leftVal in -4..4) {
+                        translateExpressionInternal(expr.right)
+                        if(rightDt in ByteDatatypes) {
+                            val incdec = if(leftVal<0) "dec" else "inc"
+                            repeat(leftVal.absoluteValue) {
+                                asmgen.out("  $incdec  P8ESTACK_LO+1,x")
+                            }
+                        } else {
+                            // word
+                            if(leftVal<0) {
+                                repeat(leftVal.absoluteValue) {
+                                    asmgen.out("""
+                                        lda  P8ESTACK_LO+1,x
+                                        bne  +
+                                        dec  P8ESTACK_HI+1,x
++                                       dec  P8ESTACK_LO+1,x""")
+                                }
+                            } else {
+                                repeat(leftVal) {
+                                    asmgen.out("""
+                                        inc  P8ESTACK_LO+1,x
+                                        bne  +
+                                        inc  P8ESTACK_HI+1,x
++""")
+                                }
+                            }
+                        }
+                        return
+                    }
+                    else if (rightVal!=null && rightVal in -4..4)
+                    {
+                        translateExpressionInternal(expr.left)
+                        if(leftDt in ByteDatatypes) {
+                            val incdec = if(rightVal<0) "dec" else "inc"
+                            repeat(rightVal.absoluteValue) {
+                                asmgen.out("  $incdec  P8ESTACK_LO+1,x")
+                            }
+                        } else {
+                            // word
+                            if(rightVal<0) {
+                                repeat(rightVal.absoluteValue) {
+                                    asmgen.out("""
+                                        lda  P8ESTACK_LO+1,x
+                                        bne  +
+                                        dec  P8ESTACK_HI+1,x
++                                       dec  P8ESTACK_LO+1,x""")
+                                }
+                            } else {
+                                repeat(rightVal) {
+                                    asmgen.out("""
+                                        inc  P8ESTACK_LO+1,x
+                                        bne  +
+                                        inc  P8ESTACK_HI+1,x
++""")
+                                }
+                            }
+                        }
+                        return
+                    }
+                }
+            }
+            "-" -> {
+                if(leftDt in IntegerDatatypes && rightDt in IntegerDatatypes) {
+                    val rightVal = expr.right.constValue(program)?.number?.toInt()
+                    if (rightVal!=null && rightVal in -4..4)
+                    {
+                        translateExpressionInternal(expr.left)
+                        if(leftDt in ByteDatatypes) {
+                            val incdec = if(rightVal<0) "inc" else "dec"
+                            repeat(rightVal.absoluteValue) {
+                                asmgen.out("  $incdec  P8ESTACK_LO+1,x")
+                            }
+                        } else {
+                            // word
+                            if(rightVal>0) {
+                                repeat(rightVal.absoluteValue) {
+                                    asmgen.out("""
+                                        lda  P8ESTACK_LO+1,x
+                                        bne  +
+                                        dec  P8ESTACK_HI+1,x
++                                       dec  P8ESTACK_LO+1,x""")
+                                }
+                            } else {
+                                repeat(rightVal) {
+                                    asmgen.out("""
+                                        inc  P8ESTACK_LO+1,x
+                                        bne  +
+                                        inc  P8ESTACK_HI+1,x
++""")
+                                }
+                            }
+                        }
+                        return
+                    }
+                }
+            }
+            ">>" -> {
+                val amount = expr.right.constValue(program)?.number?.toInt()
+                if(amount!=null) {
+                    translateExpressionInternal(expr.left)
+                    when (leftDt) {
+                        DataType.UBYTE -> {
+                            if (amount <= 2)
+                                repeat(amount) { asmgen.out(" lsr  P8ESTACK_LO+1,x") }
+                            else {
+                                asmgen.out(" lda  P8ESTACK_LO+1,x")
+                                repeat(amount) { asmgen.out(" lsr  a") }
+                                asmgen.out(" sta  P8ESTACK_LO+1,x")
+                            }
+                        }
+                        DataType.BYTE -> {
+                            if (amount <= 2)
+                                repeat(amount) { asmgen.out(" lda  P8ESTACK_LO+1,x |  asl  a |  ror  P8ESTACK_LO+1,x") }
+                            else {
+                                asmgen.out(" lda  P8ESTACK_LO+1,x |  sta  P8ZP_SCRATCH_B1")
+                                repeat(amount) { asmgen.out(" asl  a |  ror  P8ZP_SCRATCH_B1 |  lda  P8ZP_SCRATCH_B1") }
+                                asmgen.out(" sta  P8ESTACK_LO+1,x")
+                            }
+                        }
+                        DataType.UWORD -> {
+                            if(amount>=16) {
+                                if(asmgen.isTargetCpu(CpuType.CPU65c02))
+                                    asmgen.out("  stz  P8ESTACK_LO+1,x |  stz  P8ESTACK_HI+1,x")
+                                else
+                                    asmgen.out("  lda  #0 |  sta  P8ESTACK_LO+1,x |  sta  P8ESTACK_HI+1,x")
+                                return
+                            }
+                            var left = amount
+                            while (left >= 7) {
+                                asmgen.out(" jsr  math.shift_right_uw_7")
+                                left -= 7
+                            }
+                            if (left in 0..2)
+                                repeat(left) { asmgen.out(" lsr  P8ESTACK_HI+1,x |  ror  P8ESTACK_LO+1,x") }
+                            else
+                                asmgen.out(" jsr  math.shift_right_uw_$left")
+                        }
+                        DataType.WORD -> {
+                            if(amount>=16) {
+                                asmgen.out("""
+                                    lda  P8ESTACK_HI+1,x
+                                    bmi  +
+                                    lda  #0
+                                    sta  P8ESTACK_LO+1,x
+                                    sta  P8ESTACK_HI+1,x
+                                    beq  ++
++                                   lda  #255
+                                    sta  P8ESTACK_LO+1,x
+                                    sta  P8ESTACK_HI+1,x
++""")
+                                return
+                            }
+                            var left = amount
+                            while (left >= 7) {
+                                asmgen.out(" jsr  math.shift_right_w_7")
+                                left -= 7
+                            }
+                            if (left in 0..2)
+                                repeat(left) { asmgen.out(" lda  P8ESTACK_HI+1,x |  asl  a  |  ror  P8ESTACK_HI+1,x |  ror  P8ESTACK_LO+1,x") }
+                            else
+                                asmgen.out(" jsr  math.shift_right_w_$left")
+                        }
+                        else -> throw AssemblyError("weird type")
+                    }
+                    return
+                }
+            }
+            "<<" -> {
+                val amount = expr.right.constValue(program)?.number?.toInt()
+                if(amount!=null) {
+                    translateExpressionInternal(expr.left)
+                    if (leftDt in ByteDatatypes) {
+                        if (amount <= 2)
+                            repeat(amount) { asmgen.out("  asl  P8ESTACK_LO+1,x") }
+                        else {
+                            asmgen.out("  lda  P8ESTACK_LO+1,x")
+                            repeat(amount) { asmgen.out("  asl  a") }
+                            asmgen.out("  sta  P8ESTACK_LO+1,x")
+                        }
+                    } else {
+                        var left = amount
+                        while (left >= 7) {
+                            asmgen.out(" jsr  math.shift_left_w_7")
+                            left -= 7
+                        }
+                        if (left in 0..2)
+                            repeat(left) { asmgen.out("  asl  P8ESTACK_LO+1,x |  rol  P8ESTACK_HI+1,x") }
+                        else
+                            asmgen.out(" jsr  math.shift_left_w_$left")
+                    }
+                    return
+                }
+            }
+            "*" -> {
+                if(leftDt in IntegerDatatypes && rightDt in IntegerDatatypes) {
+                    val leftVar = expr.left as? IdentifierReference
+                    val rightVar = expr.right as? IdentifierReference
+                    if(leftVar!=null && rightVar!=null && leftVar==rightVar)
+                        return translateSquared(leftVar, leftDt)
+                }
+
+                val value = expr.right.constValue(program)
+                if(value!=null) {
+                    if(rightDt in IntegerDatatypes) {
+                        val amount = value.number.toInt()
+                        if(amount==2) {
+                            // optimize x*2 common case
+                            translateExpressionInternal(expr.left)
+                            if(leftDt in ByteDatatypes) {
+                                asmgen.out("  asl  P8ESTACK_LO+1,x")
+                            } else {
+                                asmgen.out("  asl  P8ESTACK_LO+1,x |  rol  P8ESTACK_HI+1,x")
+                            }
+                            return
+                        }
+                        when(rightDt) {
+                            DataType.UBYTE -> {
+                                if(amount in asmgen.optimizedByteMultiplications) {
+                                    translateExpressionInternal(expr.left)
+                                    asmgen.out(" jsr  math.stack_mul_byte_$amount")
+                                    return
+                                }
+                            }
+                            DataType.BYTE -> {
+                                if(amount in asmgen.optimizedByteMultiplications) {
+                                    translateExpressionInternal(expr.left)
+                                    asmgen.out(" jsr  math.stack_mul_byte_$amount")
+                                    return
+                                }
+                                if(amount.absoluteValue in asmgen.optimizedByteMultiplications) {
+                                    translateExpressionInternal(expr.left)
+                                    asmgen.out(" jsr  prog8_lib.neg_b |  jsr  math.stack_mul_byte_${amount.absoluteValue}")
+                                    return
+                                }
+                            }
+                            DataType.UWORD -> {
+                                if(amount in asmgen.optimizedWordMultiplications) {
+                                    translateExpressionInternal(expr.left)
+                                    asmgen.out(" jsr  math.stack_mul_word_$amount")
+                                    return
+                                }
+                            }
+                            DataType.WORD -> {
+                                if(amount in asmgen.optimizedWordMultiplications) {
+                                    translateExpressionInternal(expr.left)
+                                    asmgen.out(" jsr  math.stack_mul_word_$amount")
+                                    return
+                                }
+                                if(amount.absoluteValue in asmgen.optimizedWordMultiplications) {
+                                    translateExpressionInternal(expr.left)
+                                    asmgen.out(" jsr  prog8_lib.neg_w |  jsr  math.stack_mul_word_${amount.absoluteValue}")
+                                    return
+                                }
+                            }
+                            else -> {}
+                        }
+                    }
+                }
+            }
+            "/" -> {
+                if(leftDt in IntegerDatatypes && rightDt in IntegerDatatypes) {
+                    val rightVal = expr.right.constValue(program)?.number?.toInt()
+                    if(rightVal!=null && rightVal==2) {
+                        translateExpressionInternal(expr.left)
+                        when(leftDt) {
+                            DataType.UBYTE -> asmgen.out("  lsr  P8ESTACK_LO+1,x")
+                            DataType.BYTE -> asmgen.out("  lda  P8ESTACK_LO+1,x |  asl  a |  ror  P8ESTACK_LO+1,x")
+                            DataType.UWORD -> asmgen.out("  lsr  P8ESTACK_HI+1,x |  ror  P8ESTACK_LO+1,x")
+                            DataType.WORD -> asmgen.out("  lda  P8ESTACK_HI+1,x |  asl  a |  ror  P8ESTACK_HI+1,x |  ror  P8ESTACK_LO+1,x")
+                            else -> throw AssemblyError("wrong dt")
+                        }
+                        return
+                    }
+                }
+            }
+            in ComparisonOperators -> {
+                if(leftDt in NumericDatatypes && rightDt in NumericDatatypes) {
+                    val rightVal = expr.right.constValue(program)?.number?.toInt()
+                    if(rightVal==0)
+                        return translateComparisonWithZero(expr.left, leftDt, expr.operator)
+                }
+            }
+        }
+
+        if((leftDt in ByteDatatypes && rightDt !in ByteDatatypes)
+                || (leftDt in WordDatatypes && rightDt !in WordDatatypes))
+            throw AssemblyError("binary operator ${expr.operator} left/right dt not identical")
+
+        if(leftDt==DataType.STR && rightDt==DataType.STR && expr.operator in ComparisonOperators) {
+            translateCompareStrings(expr.left, expr.operator, expr.right)
+        }
+        else {
+            // the general, non-optimized cases  TODO optimize more cases.... (or one day just don't use the evalstack at all anymore)
+            translateExpressionInternal(expr.left)
+            translateExpressionInternal(expr.right)
+            when (leftDt) {
+                in ByteDatatypes -> translateBinaryOperatorBytes(expr.operator, leftDt)
+                in WordDatatypes -> translateBinaryOperatorWords(expr.operator, leftDt)
+                DataType.FLOAT -> translateBinaryOperatorFloats(expr.operator)
+                else -> throw AssemblyError("non-numerical datatype")
+            }
+        }
+    }
+
+    private fun translateComparisonWithZero(expr: Expression, dt: DataType, operator: String) {
+        translateExpressionInternal(expr)
+        when(operator) {
+            "==" -> {
+                when(dt) {
+                    DataType.UBYTE, DataType.BYTE -> asmgen.out("  jsr  prog8_lib.equalzero_b")
+                    DataType.UWORD, DataType.WORD -> asmgen.out("  jsr  prog8_lib.equalzero_w")
+                    DataType.FLOAT -> asmgen.out("  jsr  floats.equal_zero")
+                    else -> throw AssemblyError("wrong dt")
+                }
+            }
+            "!=" -> {
+                when(dt) {
+                    DataType.UBYTE, DataType.BYTE -> asmgen.out("  jsr  prog8_lib.notequalzero_b")
+                    DataType.UWORD, DataType.WORD -> asmgen.out("  jsr  prog8_lib.notequalzero_w")
+                    DataType.FLOAT -> asmgen.out("  jsr  floats.notequal_zero")
+                    else -> throw AssemblyError("wrong dt")
+                }
+            }
+            "<" -> {
+                if(dt==DataType.UBYTE || dt==DataType.UWORD)
+                    return translateExpressionInternal(NumericLiteral.fromBoolean(false, expr.position))
+                when(dt) {
+                    DataType.BYTE -> asmgen.out("  jsr  prog8_lib.lesszero_b")
+                    DataType.WORD -> asmgen.out("  jsr  prog8_lib.lesszero_w")
+                    DataType.FLOAT -> asmgen.out("  jsr  floats.less_zero")
+                    else -> throw AssemblyError("wrong dt")
+                }
+            }
+            ">" -> {
+                when(dt) {
+                    DataType.UBYTE -> asmgen.out("  jsr  prog8_lib.greaterzero_ub")
+                    DataType.BYTE -> asmgen.out("  jsr  prog8_lib.greaterzero_sb")
+                    DataType.UWORD -> asmgen.out("  jsr  prog8_lib.greaterzero_uw")
+                    DataType.WORD -> asmgen.out("  jsr  prog8_lib.greaterzero_sw")
+                    DataType.FLOAT -> asmgen.out("  jsr  floats.greater_zero")
+                    else -> throw AssemblyError("wrong dt")
+                }
+            }
+            "<=" -> {
+                when(dt) {
+                    DataType.UBYTE -> asmgen.out("  jsr  prog8_lib.equalzero_b")
+                    DataType.BYTE -> asmgen.out("  jsr  prog8_lib.lessequalzeros_b")
+                    DataType.UWORD -> asmgen.out("  jsr  prog8_lib.equalzero_w")
+                    DataType.WORD -> asmgen.out("  jsr  prog8_lib.lessequalzero_sw")
+                    DataType.FLOAT -> asmgen.out("  jsr  floats.lessequal_zero")
+                    else -> throw AssemblyError("wrong dt")
+                }
+            }
+            ">=" -> {
+                if(dt==DataType.UBYTE || dt==DataType.UWORD)
+                    return translateExpressionInternal(NumericLiteral.fromBoolean(true, expr.position))
+                when(dt) {
+                    DataType.BYTE -> asmgen.out("  jsr  prog8_lib.greaterequalzero_sb")
+                    DataType.WORD -> asmgen.out("  jsr  prog8_lib.greaterequalzero_sw")
+                    DataType.FLOAT -> asmgen.out("  jsr  floats.greaterequal_zero")
+                    else -> throw AssemblyError("wrong dt")
+                }
+            }
+            else -> throw AssemblyError("invalid comparison operator")
+        }
+    }
+
+    private fun translateSquared(variable: IdentifierReference, dt: DataType) {
+        val asmVar = asmgen.asmVariableName(variable)
+        when(dt) {
+            DataType.BYTE, DataType.UBYTE -> {
+                asmgen.out("  lda  $asmVar")
+                asmgen.signExtendAYlsb(dt)
+                asmgen.out("  jsr  math.square")
+            }
+            DataType.UWORD, DataType.WORD -> {
+                asmgen.out("  lda  $asmVar |  ldy  $asmVar+1 |  jsr  math.square")
+            }
+            else -> throw AssemblyError("require integer dt for square")
+        }
+        asmgen.out("  sta  P8ESTACK_LO,x |  tya |  sta  P8ESTACK_HI,x |  dex")
+    }
+
+    private fun translateExpression(expr: PrefixExpression) {
+        translateExpressionInternal(expr.expression)
+        val itype = expr.inferType(program)
+        val type = itype.getOrElse { throw AssemblyError("unknown dt") }
+        when(expr.operator) {
+            "+" -> {}
+            "-" -> {
+                when(type) {
+                    in ByteDatatypes -> asmgen.out("  jsr  prog8_lib.neg_b")
+                    in WordDatatypes -> asmgen.out("  jsr  prog8_lib.neg_w")
+                    DataType.FLOAT -> asmgen.out("  jsr  floats.neg_f")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "~" -> {
+                when(type) {
+                    in ByteDatatypes ->
+                        asmgen.out("""
+                            lda  P8ESTACK_LO+1,x
+                            eor  #255
+                            sta  P8ESTACK_LO+1,x
+                            """)
+                    in WordDatatypes -> asmgen.out("  jsr  prog8_lib.inv_word")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            "not" -> {
+                when(type) {
+                    // if reg==0 ->
+                    /*
+        lda  P8ESTACK_LO+1,x
+		beq  +
+		lda  #1
++		eor  #1
+		sta  P8ESTACK_LO+1,x
+		rts
+                     */
+                    in ByteDatatypes -> asmgen.out("  jsr  prog8_lib.not_byte")
+                    in WordDatatypes -> asmgen.out("  jsr  prog8_lib.not_word")
+                    else -> throw AssemblyError("weird type")
+                }
+            }
+            else -> throw AssemblyError("invalid prefix operator ${expr.operator}")
+        }
+    }
+
+    private fun translateExpression(arrayExpr: ArrayIndexedExpression) {
+        val elementIDt = arrayExpr.inferType(program)
+        if(!elementIDt.isKnown)
+            throw AssemblyError("unknown dt")
+        val elementDt = elementIDt.getOr(DataType.UNDEFINED)
+        val arrayVarName = asmgen.asmVariableName(arrayExpr.arrayvar)
+        val constIndexNum = arrayExpr.indexer.constIndex()
+        if(constIndexNum!=null) {
+            val indexValue = constIndexNum * program.memsizer.memorySize(elementDt)
+            when(elementDt) {
+                in ByteDatatypes -> {
+                    asmgen.out("  lda  $arrayVarName+$indexValue |  sta  P8ESTACK_LO,x |  dex")
+                }
+                in WordDatatypes -> {
+                    asmgen.out("  lda  $arrayVarName+$indexValue |  sta  P8ESTACK_LO,x |  lda  $arrayVarName+$indexValue+1 |  sta  P8ESTACK_HI,x |  dex")
+                }
+                DataType.FLOAT -> {
+                    asmgen.out("  lda  #<($arrayVarName+$indexValue) |  ldy  #>($arrayVarName+$indexValue) |  jsr  floats.push_float")
+                }
+                else -> throw AssemblyError("weird element type")
+            }
+        } else {
+            when(elementDt) {
+                in ByteDatatypes -> {
+                    asmgen.loadScaledArrayIndexIntoRegister(arrayExpr, elementDt, CpuRegister.Y)
+                    asmgen.out(" lda  $arrayVarName,y |  sta  P8ESTACK_LO,x |  dex")
+                }
+                in WordDatatypes -> {
+                    asmgen.loadScaledArrayIndexIntoRegister(arrayExpr, elementDt, CpuRegister.Y)
+                    asmgen.out(" lda  $arrayVarName,y |  sta  P8ESTACK_LO,x |  lda  $arrayVarName+1,y |  sta  P8ESTACK_HI,x |  dex")
+                }
+                DataType.FLOAT -> {
+                    asmgen.loadScaledArrayIndexIntoRegister(arrayExpr, elementDt, CpuRegister.A)
+                    asmgen.out("""
+                        ldy  #>$arrayVarName
+                        clc
+                        adc  #<$arrayVarName
+                        bcc  +
+                        iny
++                       jsr  floats.push_float""")
+                }
+                else -> throw AssemblyError("weird dt")
+            }
+
+        }
+    }
+
+    private fun translateBinaryOperatorBytes(operator: String, types: DataType) {
+        when(operator) {
+            "*" -> asmgen.out("  jsr  prog8_lib.mul_byte")  //  the optimized routines should have been checked earlier
+            "/" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.idiv_ub" else "  jsr  prog8_lib.idiv_b")
+            "%" -> {
+                if(types==DataType.BYTE)
+                    throw AssemblyError("remainder of signed integers is not properly defined/implemented, use unsigned instead")
+                asmgen.out("  jsr prog8_lib.remainder_ub")
+            }
+            "+" -> asmgen.out("""
+                lda  P8ESTACK_LO+2,x
+                clc
+                adc  P8ESTACK_LO+1,x
+                inx
+                sta  P8ESTACK_LO+1,x
+                """)
+            "-" -> asmgen.out("""
+                lda  P8ESTACK_LO+2,x
+                sec
+                sbc  P8ESTACK_LO+1,x
+                inx
+                sta  P8ESTACK_LO+1,x
+                """)
+            "<<" -> asmgen.out("  jsr  prog8_lib.shiftleft_b")
+            ">>" -> asmgen.out("  jsr  prog8_lib.shiftright_b")
+            "<" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.less_ub" else "  jsr  prog8_lib.less_b")
+            ">" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.greater_ub" else "  jsr  prog8_lib.greater_b")
+            "<=" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.lesseq_ub" else "  jsr  prog8_lib.lesseq_b")
+            ">=" -> asmgen.out(if(types==DataType.UBYTE) "  jsr  prog8_lib.greatereq_ub" else "  jsr  prog8_lib.greatereq_b")
+            "==" -> asmgen.out("  jsr  prog8_lib.equal_b")
+            "!=" -> asmgen.out("  jsr  prog8_lib.notequal_b")
+            "&" -> asmgen.out("  jsr  prog8_lib.bitand_b")
+            "^" -> asmgen.out("  jsr  prog8_lib.bitxor_b")
+            "|" -> asmgen.out("  jsr  prog8_lib.bitor_b")
+            "and" -> asmgen.out("  jsr  prog8_lib.and_b")
+            "or" -> asmgen.out("  jsr  prog8_lib.or_b")
+            "xor" -> asmgen.out("  jsr  prog8_lib.xor_b")
+            else -> throw AssemblyError("invalid operator $operator")
+        }
+    }
+
+    private fun translateBinaryOperatorWords(operator: String, dt: DataType) {
+        when(operator) {
+            "*" -> asmgen.out("  jsr  prog8_lib.mul_word")
+            "/" -> asmgen.out(if(dt==DataType.UWORD) "  jsr  prog8_lib.idiv_uw" else "  jsr  prog8_lib.idiv_w")
+            "%" -> {
+                if(dt==DataType.WORD)
+                    throw AssemblyError("remainder of signed integers is not properly defined/implemented, use unsigned instead")
+                asmgen.out("  jsr prog8_lib.remainder_uw")
+            }
+            "+" -> asmgen.out("  jsr  prog8_lib.add_w")
+            "-" -> asmgen.out("  jsr  prog8_lib.sub_w")
+            "<<" -> asmgen.out("  jsr  math.shift_left_w")
+            ">>" -> {
+                if(dt==DataType.UWORD)
+                    asmgen.out("  jsr  math.shift_right_uw")
+                else
+                    asmgen.out("  jsr  math.shift_right_w")
+            }
+            "<" -> asmgen.out(if(dt==DataType.UWORD) "  jsr  prog8_lib.less_uw" else "  jsr  prog8_lib.less_w")
+            ">" -> asmgen.out(if(dt==DataType.UWORD) "  jsr  prog8_lib.greater_uw" else "  jsr  prog8_lib.greater_w")
+            "<=" -> asmgen.out(if(dt==DataType.UWORD) "  jsr  prog8_lib.lesseq_uw" else "  jsr  prog8_lib.lesseq_w")
+            ">=" -> asmgen.out(if(dt==DataType.UWORD) "  jsr  prog8_lib.greatereq_uw" else "  jsr  prog8_lib.greatereq_w")
+            "==" -> asmgen.out("  jsr  prog8_lib.equal_w")
+            "!=" -> asmgen.out("  jsr  prog8_lib.notequal_w")
+            "&" -> asmgen.out("  jsr  prog8_lib.bitand_w")
+            "^" -> asmgen.out("  jsr  prog8_lib.bitxor_w")
+            "|" -> asmgen.out("  jsr  prog8_lib.bitor_w")
+            "and" -> asmgen.out("  jsr  prog8_lib.and_w")
+            "or" -> asmgen.out("  jsr  prog8_lib.or_w")
+            "xor" -> asmgen.out("  jsr  prog8_lib.xor_w")
+            else -> throw AssemblyError("invalid operator $operator")
+        }
+    }
+
+    private fun translateBinaryOperatorFloats(operator: String) {
+        when(operator) {
+            "*" -> asmgen.out("  jsr  floats.mul_f")
+            "/" -> asmgen.out("  jsr  floats.div_f")
+            "+" -> asmgen.out("  jsr  floats.add_f")
+            "-" -> asmgen.out("  jsr  floats.sub_f")
+            "<" -> asmgen.out("  jsr  floats.less_f")
+            ">" -> asmgen.out("  jsr  floats.greater_f")
+            "<=" -> asmgen.out("  jsr  floats.lesseq_f")
+            ">=" -> asmgen.out("  jsr  floats.greatereq_f")
+            "==" -> asmgen.out("  jsr  floats.equal_f")
+            "!=" -> asmgen.out("  jsr  floats.notequal_f")
+            "%", "<<", ">>", "&", "^", "|", "and", "or", "xor" -> throw AssemblyError("requires integer datatype")
+            else -> throw AssemblyError("invalid operator $operator")
+        }
+    }
+
+    private fun translateCompareStrings(s1: Expression, operator: String, s2: Expression) {
+        asmgen.assignExpressionToVariable(s1, "prog8_lib.strcmp_expression._arg_s1", DataType.UWORD, null)
+        asmgen.assignExpressionToVariable(s2, "prog8_lib.strcmp_expression._arg_s2", DataType.UWORD, null)
+        asmgen.out(" jsr  prog8_lib.strcmp_expression")    // result  of compare is in A
+        when(operator) {
+            "==" -> asmgen.out(" and  #1 |  eor  #1 |  sta  P8ESTACK_LO,x")
+            "!=" -> asmgen.out(" and  #1 |  sta  P8ESTACK_LO,x")
+            "<=" -> asmgen.out("""
+                bpl  +
+                lda  #1
+                bne  ++
++               lda  #0
++               sta  P8ESTACK_LO,x""")
+            ">=" -> asmgen.out("""
+                bmi  +
+                lda  #1
+                bne  ++
++               lda  #0
++               sta  P8ESTACK_LO,x""")
+            "<" -> asmgen.out("""
+                bmi  +
+                lda  #0
+                beq  ++
++               lda  #1
++               sta  P8ESTACK_LO,x""")
+            ">" -> asmgen.out("""
+                bpl  +
+                lda  #0
+                beq  ++
++               lda  #1
++               sta  P8ESTACK_LO,x""")
+        }
+        asmgen.out("  dex")
+    }
+}

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

@@ -1,40 +1,36 @@
-package prog8.compiler.target.cpu6502.codegen
+package prog8.codegen.cpu6502
 
+import com.github.michaelbull.result.fold
 import prog8.ast.Program
-import prog8.ast.base.ArrayToElementTypes
-import prog8.ast.base.DataType
-import prog8.ast.base.RegisterOrPair
 import prog8.ast.expressions.IdentifierReference
-import prog8.ast.expressions.RangeExpr
+import prog8.ast.expressions.RangeExpression
 import prog8.ast.statements.ForLoop
-import prog8.ast.toHex
-import prog8.compiler.target.AssemblyError
-import prog8.compilerinterface.toConstantIntegerRange
+import prog8.code.core.*
 import kotlin.math.absoluteValue
 
-internal class ForLoopsAsmGen(private val program: Program, private val asmgen: AsmGen) {
+internal class ForLoopsAsmGen(private val program: Program, private val asmgen: AsmGen, private val zeropage: Zeropage) {
 
     internal fun translate(stmt: ForLoop) {
         val iterableDt = stmt.iterable.inferType(program)
         if(!iterableDt.isKnown)
             throw AssemblyError("unknown dt")
         when(stmt.iterable) {
-            is RangeExpr -> {
-                val range = (stmt.iterable as RangeExpr).toConstantIntegerRange()
+            is RangeExpression -> {
+                val range = (stmt.iterable as RangeExpression).toConstantIntegerRange()
                 if(range==null) {
-                    translateForOverNonconstRange(stmt, iterableDt.getOr(DataType.UNDEFINED), stmt.iterable as RangeExpr)
+                    translateForOverNonconstRange(stmt, iterableDt.getOrElse { throw AssemblyError("unknown dt") }, stmt.iterable as RangeExpression)
                 } else {
-                    translateForOverConstRange(stmt, iterableDt.getOr(DataType.UNDEFINED), range)
+                    translateForOverConstRange(stmt, iterableDt.getOrElse { throw AssemblyError("unknown dt") }, range)
                 }
             }
             is IdentifierReference -> {
-                translateForOverIterableVar(stmt, iterableDt.getOr(DataType.UNDEFINED), stmt.iterable as IdentifierReference)
+                translateForOverIterableVar(stmt, iterableDt.getOrElse { throw AssemblyError("unknown dt") }, stmt.iterable as IdentifierReference)
             }
             else -> throw AssemblyError("can't iterate over ${stmt.iterable.javaClass} - should have been replaced by a variable")
         }
     }
 
-    private fun translateForOverNonconstRange(stmt: ForLoop, iterableDt: DataType, range: RangeExpr) {
+    private fun translateForOverNonconstRange(stmt: ForLoop, iterableDt: DataType, range: RangeExpression) {
         val loopLabel = asmgen.makeLabel("for_loop")
         val endLabel = asmgen.makeLabel("for_end")
         val modifiedLabel = asmgen.makeLabel("for_modified")
@@ -43,7 +39,7 @@ internal class ForLoopsAsmGen(private val program: Program, private val asmgen:
         val stepsize=range.step.constValue(program)!!.number.toInt()
 
         if(stepsize < -1) {
-            val limit = range.to.constValue(program)?.number?.toDouble()
+            val limit = range.to.constValue(program)?.number
             if(limit==0.0)
                 throw AssemblyError("for unsigned loop variable it's not possible to count down with step != -1 from a non-const value to exactly zero due to value wrapping")
         }
@@ -289,13 +285,15 @@ $loopLabel          sty  $indexVar
                         bne  $loopLabel
                         beq  $endLabel""")
                 }
-                if(length>=16 && asmgen.zeropage.hasByteAvailable()) {
-                    // allocate index var on ZP
-                    val zpAddr = asmgen.zeropage.allocate(indexVar, DataType.UBYTE, stmt.position, asmgen.errors)
-                    asmgen.out("""$indexVar = $zpAddr  ; auto zp UBYTE""")
+                if(length>=16) {
+                    // allocate index var on ZP if possible
+                    val result = zeropage.allocate(listOf(indexVar), DataType.UBYTE, null, stmt.position, asmgen.errors)
+                    result.fold(
+                        success = { (address,_)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
+                        failure = { asmgen.out("$indexVar    .byte  0") }
+                    )
                 } else {
-                    asmgen.out("""
-$indexVar           .byte  0""")
+                    asmgen.out("$indexVar    .byte  0")
                 }
                 asmgen.out(endLabel)
             }
@@ -328,13 +326,15 @@ $loopLabel          sty  $indexVar
                         bne  $loopLabel
                         beq  $endLabel""")
                 }
-                if(length>=16 && asmgen.zeropage.hasByteAvailable()) {
-                    // allocate index var on ZP
-                    val zpAddr = asmgen.zeropage.allocate(indexVar, DataType.UBYTE, stmt.position, asmgen.errors)
-                    asmgen.out("""$indexVar = $zpAddr  ; auto zp UBYTE""")
+                if(length>=16) {
+                    // allocate index var on ZP if possible
+                    val result = zeropage.allocate(listOf(indexVar), DataType.UBYTE, null, stmt.position, asmgen.errors)
+                    result.fold(
+                        success = { (address,_)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
+                        failure = { asmgen.out("$indexVar    .byte  0") }
+                    )
                 } else {
-                    asmgen.out("""
-$indexVar           .byte  0""")
+                    asmgen.out("$indexVar    .byte  0")
                 }
                 asmgen.out(endLabel)
             }
@@ -588,6 +588,10 @@ $loopLabel""")
         asmgen.loopEndLabels.pop()
     }
 
-    private fun assignLoopvar(stmt: ForLoop, range: RangeExpr) =
-        asmgen.assignExpressionToVariable(range.from, asmgen.asmVariableName(stmt.loopVar), stmt.loopVarDt(program).getOr(DataType.UNDEFINED), stmt.definingSubroutine)
+    private fun assignLoopvar(stmt: ForLoop, range: RangeExpression) =
+        asmgen.assignExpressionToVariable(
+            range.from,
+            asmgen.asmVariableName(stmt.loopVar),
+            stmt.loopVarDt(program).getOrElse { throw AssemblyError("unknown dt") },
+            stmt.definingSubroutine)
 }

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

@@ -0,0 +1,274 @@
+package prog8.codegen.cpu6502
+
+import prog8.ast.IFunctionCall
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.expressions.AddressOf
+import prog8.ast.expressions.Expression
+import prog8.ast.expressions.IdentifierReference
+import prog8.ast.expressions.NumericLiteral
+import prog8.ast.statements.*
+import prog8.code.core.*
+import prog8.codegen.cpu6502.assignment.AsmAssignSource
+import prog8.codegen.cpu6502.assignment.AsmAssignTarget
+import prog8.codegen.cpu6502.assignment.AsmAssignment
+import prog8.codegen.cpu6502.assignment.TargetStorageKind
+
+
+internal class FunctionCallAsmGen(private val program: Program, private val asmgen: AsmGen) {
+
+    internal fun translateFunctionCallStatement(stmt: FunctionCallStatement) {
+        saveXbeforeCall(stmt)
+        translateFunctionCall(stmt, false)
+        restoreXafterCall(stmt)
+        // just ignore any result values from the function call.
+    }
+
+    internal fun saveXbeforeCall(stmt: IFunctionCall) {
+        val sub = stmt.target.targetSubroutine(program) ?: throw AssemblyError("undefined subroutine ${stmt.target}")
+        if(sub.shouldSaveX()) {
+            val regSaveOnStack = sub.asmAddress==null       // rom-routines don't require registers to be saved on stack, normal subroutines do because they can contain nested calls
+            if(regSaveOnStack)
+                asmgen.saveRegisterStack(CpuRegister.X, sub.shouldKeepA().saveOnEntry)
+            else
+                asmgen.saveRegisterLocal(CpuRegister.X, (stmt as Node).definingSubroutine!!)
+        }
+    }
+
+    internal fun saveXbeforeCall(gosub: GoSub) {
+        val sub = gosub.identifier.targetSubroutine(program)
+        if(sub?.shouldSaveX()==true) {
+            val regSaveOnStack = sub.asmAddress==null       // rom-routines don't require registers to be saved on stack, normal subroutines do because they can contain nested calls
+            if(regSaveOnStack)
+                asmgen.saveRegisterStack(CpuRegister.X, sub.shouldKeepA().saveOnEntry)
+            else
+                asmgen.saveRegisterLocal(CpuRegister.X, gosub.definingSubroutine!!)
+        }
+    }
+
+    internal fun restoreXafterCall(stmt: IFunctionCall) {
+        val sub = stmt.target.targetSubroutine(program) ?: throw AssemblyError("undefined subroutine ${stmt.target}")
+        if(sub.shouldSaveX()) {
+            val regSaveOnStack = sub.asmAddress==null       // rom-routines don't require registers to be saved on stack, normal subroutines do because they can contain nested calls
+            if(regSaveOnStack)
+                asmgen.restoreRegisterStack(CpuRegister.X, sub.shouldKeepA().saveOnReturn)
+            else
+                asmgen.restoreRegisterLocal(CpuRegister.X)
+        }
+    }
+
+    internal fun restoreXafterCall(gosub: GoSub) {
+        val sub = gosub.identifier.targetSubroutine(program)
+        if(sub?.shouldSaveX()==true) {
+            val regSaveOnStack = sub.asmAddress==null       // rom-routines don't require registers to be saved on stack, normal subroutines do because they can contain nested calls
+            if(regSaveOnStack)
+                asmgen.restoreRegisterStack(CpuRegister.X, sub.shouldKeepA().saveOnReturn)
+            else
+                asmgen.restoreRegisterLocal(CpuRegister.X)
+        }
+    }
+
+    internal fun optimizeIntArgsViaRegisters(sub: Subroutine) =
+        (sub.parameters.size==1 && sub.parameters[0].type in IntegerDatatypes)
+                || (sub.parameters.size==2 && sub.parameters[0].type in ByteDatatypes && sub.parameters[1].type in ByteDatatypes)
+
+    internal fun translateFunctionCall(call: IFunctionCall, isExpression: Boolean) {
+        // Output only the code to set up the parameters and perform the actual call
+        // NOTE: does NOT output the code to deal with the result values!
+        // NOTE: does NOT output code to save/restore the X register for this call! Every caller should deal with this in their own way!!
+        //       (you can use subroutine.shouldSaveX() and saveX()/restoreX() routines as a help for this)
+
+        val sub = call.target.targetSubroutine(program) ?: throw AssemblyError("undefined subroutine ${call.target}")
+        val subAsmName = asmgen.asmSymbolName(call.target)
+
+        if(!isExpression && !sub.isAsmSubroutine) {
+            if(!optimizeIntArgsViaRegisters(sub))
+                throw AssemblyError("functioncall statements to non-asmsub should have been replaced by GoSub $call")
+        }
+
+        if(sub.isAsmSubroutine) {
+            argumentsViaRegisters(sub, call)
+            if (sub.inline && asmgen.options.optimize) {
+                // inline the subroutine.
+                // we do this by copying the subroutine's statements at the call site.
+                // NOTE: *if* there is a return statement, it will be the only one, and the very last statement of the subroutine
+                // (this condition has been enforced by an ast check earlier)
+                asmgen.out("  \t; inlined routine follows: ${sub.name}")
+                sub.statements.forEach { asmgen.translate(it as InlineAssembly) }
+                asmgen.out("  \t; inlined routine end: ${sub.name}")
+            } else {
+                asmgen.out("  jsr  $subAsmName")
+            }
+        }
+        else {
+            if(sub.inline)
+                throw AssemblyError("can only reliably inline asmsub routines at this time")
+
+            if(optimizeIntArgsViaRegisters(sub)) {
+                if(sub.parameters.size==1) {
+                    val register = if (sub.parameters[0].type in ByteDatatypes) RegisterOrPair.A else RegisterOrPair.AY
+                    argumentViaRegister(sub, IndexedValue(0, sub.parameters[0]), call.args[0], register)
+                } else {
+                    // 2 byte params, second in Y, first in A
+                    argumentViaRegister(sub, IndexedValue(0, sub.parameters[0]), call.args[0], RegisterOrPair.A)
+                    if(!call.args[1].isSimple)
+                        asmgen.out("  pha")
+                    argumentViaRegister(sub, IndexedValue(1, sub.parameters[1]), call.args[1], RegisterOrPair.Y)
+                    if(!call.args[1].isSimple)
+                        asmgen.out("  pla")
+                }
+            } else {
+                // arguments via variables
+                for(arg in sub.parameters.withIndex().zip(call.args))
+                    argumentViaVariable(sub, arg.first.value, arg.second)
+            }
+            asmgen.out("  jsr  $subAsmName")
+        }
+
+        // remember: dealing with the X register and/or dealing with return values is the responsibility of the caller
+    }
+
+    private fun argumentsViaRegisters(sub: Subroutine, call: IFunctionCall) {
+        if(sub.parameters.size==1) {
+            argumentViaRegister(sub, IndexedValue(0, sub.parameters.single()), call.args[0])
+        } else {
+            if(asmsub6502ArgsHaveRegisterClobberRisk(call.args, sub.asmParameterRegisters)) {
+                registerArgsViaCpuStackEvaluation(call, sub)
+            } else {
+                asmsub6502ArgsEvalOrder(sub).forEach {
+                    val param = sub.parameters[it]
+                    val arg = call.args[it]
+                    argumentViaRegister(sub, IndexedValue(it, param), arg)
+                }
+            }
+        }
+    }
+
+    private fun registerArgsViaCpuStackEvaluation(call: IFunctionCall, callee: Subroutine) {
+        // this is called when one or more of the arguments are 'complex' and
+        // cannot be assigned to a register easily or risk clobbering other registers.
+
+        require(callee.isAsmSubroutine)
+        if(callee.parameters.isEmpty())
+            return
+
+        // use the cpu hardware stack as intermediate storage for the arguments.
+        val argOrder = asmsub6502ArgsEvalOrder(callee)
+        argOrder.reversed().forEach {
+            asmgen.pushCpuStack(callee.parameters[it].type, call.args[it])
+        }
+        argOrder.forEach {
+            val param = callee.parameters[it]
+            val targetVar = callee.searchAsmParameter(param.name)!!
+            asmgen.popCpuStack(param.type, targetVar, (call as Node).definingSubroutine)
+        }
+    }
+
+    private fun argumentViaVariable(sub: Subroutine, parameter: SubroutineParameter, value: Expression) {
+        // pass parameter via a regular variable (not via registers)
+        val valueIDt = value.inferType(program)
+        val valueDt = valueIDt.getOrElse { throw AssemblyError("unknown dt") }
+        if(!isArgumentTypeCompatible(valueDt, parameter.type))
+            throw AssemblyError("argument type incompatible")
+
+        val varName = asmgen.asmVariableName(sub.scopedName + parameter.name)
+        asmgen.assignExpressionToVariable(value, varName, parameter.type, sub)
+    }
+
+    private fun argumentViaRegister(sub: Subroutine, parameter: IndexedValue<SubroutineParameter>, value: Expression, registerOverride: RegisterOrPair? = null) {
+        // pass argument via a register parameter
+        val valueIDt = value.inferType(program)
+        val valueDt = valueIDt.getOrElse { throw AssemblyError("unknown dt") }
+        if(!isArgumentTypeCompatible(valueDt, parameter.value.type))
+            throw AssemblyError("argument type incompatible")
+
+        val paramRegister = if(registerOverride==null) sub.asmParameterRegisters[parameter.index] else RegisterOrStatusflag(registerOverride, null)
+        val statusflag = paramRegister.statusflag
+        val register = paramRegister.registerOrPair
+        val requiredDt = parameter.value.type
+        if(requiredDt!=valueDt) {
+            if(valueDt largerThan requiredDt)
+                throw AssemblyError("can only convert byte values to word param types")
+        }
+        if (statusflag!=null) {
+            if(requiredDt!=valueDt)
+                throw AssemblyError("for statusflag, byte value is required")
+            if (statusflag == Statusflag.Pc) {
+                // this param needs to be set last, right before the jsr
+                // for now, this is already enforced on the subroutine definition by the Ast Checker
+                when(value) {
+                    is NumericLiteral -> {
+                        val carrySet = value.number.toInt() != 0
+                        asmgen.out(if(carrySet) "  sec" else "  clc")
+                    }
+                    is IdentifierReference -> {
+                        val sourceName = asmgen.asmVariableName(value)
+                        asmgen.out("""
+                            pha
+                            clc
+                            lda  $sourceName
+                            beq  +
+                            sec  
++                           pla""")
+                    }
+                    else -> {
+                        asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
+                        asmgen.out("""
+                            beq  +
+                            sec
+                            bcs  ++
++                           clc
++""")
+                    }
+                }
+            } else throw AssemblyError("can only use Carry as status flag parameter")
+        }
+        else {
+            // via register or register pair
+            register!!
+            if(requiredDt largerThan valueDt) {
+                // we need to sign extend the source, do this via temporary word variable
+                asmgen.assignExpressionToVariable(value, "P8ZP_SCRATCH_W1", DataType.UBYTE, sub)
+                asmgen.signExtendVariableLsb("P8ZP_SCRATCH_W1", valueDt)
+                asmgen.assignVariableToRegister("P8ZP_SCRATCH_W1", register)
+            } else {
+                val target: AsmAssignTarget =
+                    if(parameter.value.type in ByteDatatypes && (register==RegisterOrPair.AX || register == RegisterOrPair.AY || register==RegisterOrPair.XY || register in Cx16VirtualRegisters))
+                        AsmAssignTarget(TargetStorageKind.REGISTER, program, asmgen, parameter.value.type, sub, register = register)
+                    else {
+                        val signed = parameter.value.type == DataType.BYTE || parameter.value.type == DataType.WORD
+                        AsmAssignTarget.fromRegisters(register, signed, sub, program, asmgen)
+                    }
+                val src = if(valueDt in PassByReferenceDatatypes) {
+                    if(value is IdentifierReference) {
+                        val addr = AddressOf(value, Position.DUMMY)
+                        AsmAssignSource.fromAstSource(addr, program, asmgen).adjustSignedUnsigned(target)
+                    } else {
+                        AsmAssignSource.fromAstSource(value, program, asmgen).adjustSignedUnsigned(target)
+                    }
+                } else {
+                    AsmAssignSource.fromAstSource(value, program, asmgen).adjustSignedUnsigned(target)
+                }
+                asmgen.translateNormalAssignment(AsmAssignment(src, target, false, program.memsizer, Position.DUMMY))
+            }
+        }
+    }
+
+    private fun isArgumentTypeCompatible(argType: DataType, paramType: DataType): Boolean {
+        if(argType isAssignableTo paramType)
+            return true
+        if(argType in ByteDatatypes && paramType in ByteDatatypes)
+            return true
+        if(argType in WordDatatypes && paramType in WordDatatypes)
+            return true
+
+        // we have a special rule for some types.
+        // strings are assignable to UWORD, for example, and vice versa
+        if(argType==DataType.STR && paramType==DataType.UWORD)
+            return true
+        if(argType==DataType.UWORD && paramType == DataType.STR)
+            return true
+
+        return false
+    }
+}

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

@@ -1,12 +1,10 @@
-package prog8.compiler.target.cpu6502.codegen
+package prog8.codegen.cpu6502
 
 import prog8.ast.Program
-import prog8.ast.base.*
 import prog8.ast.expressions.IdentifierReference
-import prog8.ast.expressions.NumericLiteralValue
+import prog8.ast.expressions.NumericLiteral
 import prog8.ast.statements.PostIncrDecr
-import prog8.ast.toHex
-import prog8.compiler.target.AssemblyError
+import prog8.code.core.*
 
 
 internal class PostIncrDecrAsmGen(private val program: Program, private val asmgen: AsmGen) {
@@ -41,7 +39,7 @@ internal class PostIncrDecrAsmGen(private val program: Program, private val asmg
             }
             targetMemory!=null -> {
                 when (val addressExpr = targetMemory.addressExpression) {
-                    is NumericLiteralValue -> {
+                    is NumericLiteral -> {
                         val what = addressExpr.number.toHex()
                         asmgen.out(if(incr) "  inc  $what" else "  dec  $what")
                     }
@@ -83,7 +81,7 @@ internal class PostIncrDecrAsmGen(private val program: Program, private val asmg
 """)
                         }
                         DataType.FLOAT -> {
-                            asmgen.out("  lda  #<$asmArrayvarname+$indexValue |  ldy  #>$asmArrayvarname+$indexValue")
+                            asmgen.out("  lda  #<($asmArrayvarname+$indexValue) |  ldy  #>($asmArrayvarname+$indexValue)")
                             asmgen.out(if(incr) "  jsr  floats.inc_var_f" else "  jsr  floats.dec_var_f")
                         }
                         else -> throw AssemblyError("need numeric type")

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

@@ -0,0 +1,639 @@
+package prog8.codegen.cpu6502
+
+import prog8.ast.Program
+import prog8.ast.antlr.escape
+import prog8.ast.statements.*
+import prog8.code.*
+import prog8.code.core.*
+import prog8.codegen.cpu6502.assignment.AsmAssignTarget
+import prog8.codegen.cpu6502.assignment.TargetStorageKind
+import prog8.compiler.CallGraph
+import java.time.LocalDate
+import java.time.LocalDateTime
+import kotlin.math.absoluteValue
+
+/**
+ * Generates the main parts of the program:
+ *  - entry/exit code
+ *  - initialization routines
+ *  - blocks
+ *  - subroutines
+ *  - all variables (note: VarDecl ast nodes are *NOT* used anymore for this! now uses IVariablesAndConsts data tables!)
+ */
+internal class ProgramAndVarsGen(
+    val program: Program,
+    val options: CompilationOptions,
+    val errors: IErrorReporter,
+    private val symboltable: SymbolTable,
+    private val functioncallAsmGen: FunctionCallAsmGen,
+    private val asmgen: AsmGen,
+    private val allocator: VariableAllocator,
+    private val zeropage: Zeropage
+) {
+    private val compTarget = options.compTarget
+    private val callGraph = CallGraph(program, true)
+    private val blockVariableInitializers = program.allBlocks.associateWith { it.statements.filterIsInstance<Assignment>() }
+
+    internal fun generate() {
+        val allInitializers = blockVariableInitializers.asSequence().flatMap { it.value }
+        require(allInitializers.all { it.origin==AssignmentOrigin.VARINIT }) {"all block-level assignments must be a variable initializer"}
+
+        header()
+        val allBlocks = program.allBlocks
+        if(allBlocks.first().name != "main")
+            throw AssemblyError("first block should be 'main'")
+
+        if(errors.noErrors())  {
+            program.allBlocks.forEach { block2asm(it) }
+            memorySlabs()
+            footer()
+        }
+    }
+
+    private fun header() {
+        val ourName = this.javaClass.name
+        val cpu = when(compTarget.machine.cpu) {
+            CpuType.CPU6502 -> "6502"
+            CpuType.CPU65c02 -> "w65c02"
+            else -> "unsupported"
+        }
+
+        asmgen.out("; $cpu assembly code for '${program.name}'")
+        asmgen.out("; generated by $ourName on ${LocalDateTime.now().withNano(0)}")
+        asmgen.out("; assembler syntax is for the 64tasm cross-assembler")
+        asmgen.out("; output options: output=${options.output} launcher=${options.launcher} zp=${options.zeropage}")
+        asmgen.out("")
+        asmgen.out(".cpu  '$cpu'\n.enc  'none'\n")
+
+        // the global prog8 variables needed
+        val zp = zeropage
+        asmgen.out("P8ZP_SCRATCH_B1 = ${zp.SCRATCH_B1}")
+        asmgen.out("P8ZP_SCRATCH_REG = ${zp.SCRATCH_REG}")
+        asmgen.out("P8ZP_SCRATCH_W1 = ${zp.SCRATCH_W1}    ; word")
+        asmgen.out("P8ZP_SCRATCH_W2 = ${zp.SCRATCH_W2}    ; word")
+        asmgen.out("P8ESTACK_LO = ${compTarget.machine.ESTACK_LO.toHex()}")
+        asmgen.out("P8ESTACK_HI = ${compTarget.machine.ESTACK_HI.toHex()}")
+
+        when(options.output) {
+            OutputType.RAW -> {
+                asmgen.out("; ---- raw assembler program ----")
+                asmgen.out("* = ${options.loadAddress.toHex()}\n")
+            }
+            OutputType.PRG -> {
+                when(options.launcher) {
+                    CbmPrgLauncherType.BASIC -> {
+                        if (options.loadAddress != options.compTarget.machine.PROGRAM_LOAD_ADDRESS) {
+                            errors.err("BASIC output must have load address ${options.compTarget.machine.PROGRAM_LOAD_ADDRESS.toHex()}", program.toplevelModule.position)
+                        }
+                        asmgen.out("; ---- basic program with sys call ----")
+                        asmgen.out("* = ${options.loadAddress.toHex()}")
+                        val year = LocalDate.now().year
+                        asmgen.out("  .word  (+), $year")
+                        asmgen.out("  .null  $9e, format(' %d ', prog8_entrypoint), $3a, $8f, ' prog8'")
+                        asmgen.out("+\t.word  0")
+                        asmgen.out("prog8_entrypoint\t; assembly code starts here\n")
+                        if(!options.noSysInit)
+                            asmgen.out("  jsr  ${compTarget.name}.init_system")
+                        asmgen.out("  jsr  ${compTarget.name}.init_system_phase2")
+                    }
+                    CbmPrgLauncherType.NONE -> {
+                        asmgen.out("; ---- program without basic sys call ----")
+                        asmgen.out("* = ${options.loadAddress.toHex()}\n")
+                        if(!options.noSysInit)
+                            asmgen.out("  jsr  ${compTarget.name}.init_system")
+                        asmgen.out("  jsr  ${compTarget.name}.init_system_phase2")
+                    }
+                }
+            }
+            OutputType.XEX -> {
+                asmgen.out("; ---- atari xex program ----")
+                asmgen.out("* = ${options.loadAddress.toHex()}\n")
+                if(!options.noSysInit)
+                    asmgen.out("  jsr  ${compTarget.name}.init_system")
+                asmgen.out("  jsr  ${compTarget.name}.init_system_phase2")
+            }
+        }
+
+        if(options.zeropage !in arrayOf(ZeropageType.BASICSAFE, ZeropageType.DONTUSE)) {
+            asmgen.out("""
+                ; zeropage is clobbered so we need to reset the machine at exit
+                lda  #>sys.reset_system
+                pha
+                lda  #<sys.reset_system
+                pha""")
+        }
+
+        // make sure that on the cx16 and c64, basic rom is banked in again when we exit the program
+        when(compTarget.name) {
+            "cx16" -> {
+                if(options.floats)
+                    asmgen.out("  lda  #4 |  sta  $01")    // to use floats, make sure Basic rom is banked in
+                asmgen.out("  jsr  main.start |  lda  #4 |  sta  $01 |  rts")
+            }
+            "c64" -> asmgen.out("  jsr  main.start |  lda  #31 |  sta  $01 |  rts")
+            else -> asmgen.jmp("main.start")
+        }
+    }
+
+    private fun memorySlabs() {
+        asmgen.out("; memory slabs")
+        asmgen.out("prog8_slabs\t.block")
+        for((name, info) in allocator.memorySlabs) {
+            if(info.second>1u)
+                asmgen.out("\t.align  ${info.second.toHex()}")
+            asmgen.out("$name\t.fill  ${info.first}")
+        }
+        asmgen.out("\t.bend")
+    }
+
+    private fun footer() {
+        // the global list of all floating point constants for the whole program
+        asmgen.out("; global float constants")
+        for (flt in allocator.globalFloatConsts) {
+            val floatFill = compTarget.machine.getFloat(flt.key).makeFloatFillAsm()
+            val floatvalue = flt.key
+            asmgen.out("${flt.value}\t.byte  $floatFill  ; float $floatvalue")
+        }
+
+        // program end
+        asmgen.out("prog8_program_end\t; end of program label for progend()")
+    }
+
+    private fun block2asm(block: Block) {
+        asmgen.out("")
+        asmgen.out("; ---- block: '${block.name}' ----")
+        if(block.address!=null)
+            asmgen.out("* = ${block.address!!.toHex()}")
+        else {
+            if("align_word" in block.options())
+                asmgen.out("\t.align 2")
+            else if("align_page" in block.options())
+                asmgen.out("\t.align $100")
+        }
+
+        asmgen.out("${block.name}\t" + (if("force_output" in block.options()) ".block\n" else ".proc\n"))
+        asmgen.outputSourceLine(block)
+
+        createBlockVariables(block)
+        asmsubs2asm(block.statements)
+
+        asmgen.out("")
+        asmgen.out("; subroutines in this block")
+
+        // First translate regular statements, and then put the subroutines at the end.
+        // (regular statements = everything except the initialization assignments;
+        // these will be part of the prog8_init_vars init routine generated below)
+        val initializers = blockVariableInitializers.getValue(block)
+        val statements = block.statements.filterNot { it in initializers }
+        val (subroutine, stmts) = statements.partition { it is Subroutine }
+        stmts.forEach { asmgen.translate(it) }
+        subroutine.forEach { asmgen.translate(it) }
+
+        if(!options.dontReinitGlobals) {
+            // generate subroutine to initialize block-level (global) variables
+            if (initializers.isNotEmpty()) {
+                asmgen.out("prog8_init_vars\t.proc\n")
+                initializers.forEach { assign -> asmgen.translate(assign) }
+                asmgen.out("  rts\n  .pend")
+            }
+        }
+
+        asmgen.out(if("force_output" in block.options()) "\n\t.bend\n" else "\n\t.pend\n")
+    }
+
+    private fun getVars(scope: StNode): Map<String, StNode> =
+        scope.children.filter { it.value.type in arrayOf(StNodeType.STATICVAR, StNodeType.CONSTANT, StNodeType.MEMVAR) }
+
+    private fun createBlockVariables(block: Block) {
+        val scope = symboltable.lookupOrElse(block.name) { throw AssemblyError("lookup") }
+        require(scope.type==StNodeType.BLOCK)
+        val varsInBlock = getVars(scope)
+
+        // Zeropage Variables
+        val varnames = varsInBlock.filter { it.value.type==StNodeType.STATICVAR }.map { it.value.scopedName }.toSet()
+        zeropagevars2asm(varnames)
+
+        // MemDefs and Consts
+        val mvs = varsInBlock
+            .filter { it.value.type==StNodeType.MEMVAR }
+            .map { it.value as StMemVar }
+        val consts = varsInBlock
+            .filter { it.value.type==StNodeType.CONSTANT }
+            .map { it.value as StConstant }
+        memdefsAndConsts2asm(mvs, consts)
+
+        // normal statically allocated variables
+        val variables = varsInBlock
+            .filter { it.value.type==StNodeType.STATICVAR && !allocator.isZpVar(it.value.scopedName) }
+            .map { it.value as StStaticVariable }
+        nonZpVariables2asm(variables)
+    }
+
+    internal fun translateSubroutine(sub: Subroutine) {
+        var onlyVariables = false
+
+        if(sub.inline) {
+            if(options.optimize) {
+                if(sub.isAsmSubroutine || callGraph.unused(sub))
+                    return
+
+                // from an inlined subroutine only the local variables are generated,
+                // all other code statements are omitted in the subroutine itself
+                // (they've been inlined at the call site, remember?)
+                onlyVariables = true
+            }
+        }
+
+        asmgen.out("")
+
+        if(sub.isAsmSubroutine) {
+            if(sub.asmAddress!=null)
+                return  // already done at the memvars section
+
+            // asmsub with most likely just an inline asm in it
+            asmgen.out("${sub.name}\t.proc")
+            sub.statements.forEach { asmgen.translate(it) }
+            asmgen.out("  .pend\n")
+        } else {
+            // regular subroutine
+            asmgen.out("${sub.name}\t.proc")
+
+            val scope = symboltable.lookupOrElse(sub.scopedName) { throw AssemblyError("lookup") }
+            require(scope.type==StNodeType.SUBROUTINE)
+            val varsInSubroutine = getVars(scope)
+
+            // Zeropage Variables
+            val varnames = varsInSubroutine.filter { it.value.type==StNodeType.STATICVAR }.map { it.value.scopedName }.toSet()
+            zeropagevars2asm(varnames)
+
+            // MemDefs and Consts
+            val mvs = varsInSubroutine
+                .filter { it.value.type==StNodeType.MEMVAR }
+                .map { it.value as StMemVar }
+            val consts = varsInSubroutine
+                .filter { it.value.type==StNodeType.CONSTANT }
+                .map { it.value as StConstant }
+            memdefsAndConsts2asm(mvs, consts)
+
+            asmsubs2asm(sub.statements)
+
+            // the main.start subroutine is the program's entrypoint and should perform some initialization logic
+            if(sub.name=="start" && sub.definingBlock.name=="main")
+                entrypointInitialization()
+
+            if(functioncallAsmGen.optimizeIntArgsViaRegisters(sub)) {
+                asmgen.out("; simple int arg(s) passed via register(s)")
+                if(sub.parameters.size==1) {
+                    val dt = sub.parameters[0].type
+                    val target = AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, dt, sub, variableAsmName = sub.parameters[0].name)
+                    if(dt in ByteDatatypes)
+                        asmgen.assignRegister(RegisterOrPair.A, target)
+                    else
+                        asmgen.assignRegister(RegisterOrPair.AY, target)
+                } else {
+                    require(sub.parameters.size==2)
+                    // 2 simple byte args, first in A, second in Y
+                    val target1 = AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, sub.parameters[0].type, sub, variableAsmName = sub.parameters[0].name)
+                    val target2 = AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, sub.parameters[1].type, sub, variableAsmName = sub.parameters[1].name)
+                    asmgen.assignRegister(RegisterOrPair.A, target1)
+                    asmgen.assignRegister(RegisterOrPair.Y, target2)
+                }
+            }
+
+            if(!onlyVariables) {
+                asmgen.out("; statements")
+                sub.statements.forEach { asmgen.translate(it) }
+            }
+
+            asmgen.out("; variables")
+            val asmGenInfo = asmgen.subroutineExtra(sub)
+            for((dt, name, addr) in asmGenInfo.extraVars) {
+                if(addr!=null)
+                    asmgen.out("$name = $addr")
+                else when(dt) {
+                    DataType.UBYTE -> asmgen.out("$name    .byte  0")
+                    DataType.UWORD -> asmgen.out("$name    .word  0")
+                    else -> throw AssemblyError("weird dt")
+                }
+            }
+            if(asmGenInfo.usedRegsaveA)      // will probably never occur
+                asmgen.out("prog8_regsaveA     .byte  0")
+            if(asmGenInfo.usedRegsaveX)
+                asmgen.out("prog8_regsaveX     .byte  0")
+            if(asmGenInfo.usedRegsaveY)
+                asmgen.out("prog8_regsaveY     .byte  0")
+            if(asmGenInfo.usedFloatEvalResultVar1)
+                asmgen.out("$subroutineFloatEvalResultVar1    .byte  0,0,0,0,0")
+            if(asmGenInfo.usedFloatEvalResultVar2)
+                asmgen.out("$subroutineFloatEvalResultVar2    .byte  0,0,0,0,0")
+
+            // normal statically allocated variables
+            val variables = varsInSubroutine
+                .filter { it.value.type==StNodeType.STATICVAR && !allocator.isZpVar(it.value.scopedName) }
+                .map { it.value as StStaticVariable }
+            nonZpVariables2asm(variables)
+
+            asmgen.out("  .pend\n")
+        }
+    }
+
+    private fun entrypointInitialization() {
+        asmgen.out("; program startup initialization")
+        asmgen.out("  cld")
+        if(!options.dontReinitGlobals) {
+            blockVariableInitializers.forEach {
+                if (it.value.isNotEmpty())
+                    asmgen.out("  jsr  ${it.key.name}.prog8_init_vars")
+            }
+        }
+
+        // string and array variables in zeropage that have initializer value, should be initialized
+        val stringVarsWithInitInZp = getZpStringVarsWithInitvalue()
+        val arrayVarsWithInitInZp = getZpArrayVarsWithInitvalue()
+        if(stringVarsWithInitInZp.isNotEmpty() || arrayVarsWithInitInZp.isNotEmpty()) {
+            asmgen.out("; zp str and array initializations")
+            stringVarsWithInitInZp.forEach {
+                val name = asmgen.asmVariableName(it.name)
+                asmgen.out("""
+                    lda  #<${name}
+                    ldy  #>${name}
+                    sta  P8ZP_SCRATCH_W1
+                    sty  P8ZP_SCRATCH_W1+1
+                    lda  #<${name}_init_value
+                    ldy  #>${name}_init_value
+                    jsr  prog8_lib.strcpy""")
+            }
+            arrayVarsWithInitInZp.forEach {
+                val size = it.alloc.size
+                val name = asmgen.asmVariableName(it.name)
+                asmgen.out("""
+                    lda  #<${name}_init_value
+                    ldy  #>${name}_init_value
+                    sta  cx16.r0L
+                    sty  cx16.r0H
+                    lda  #<${name}
+                    ldy  #>${name}
+                    sta  cx16.r1L
+                    sty  cx16.r1H
+                    lda  #<$size
+                    ldy  #>$size
+                    jsr  sys.memcopy""")
+            }
+            asmgen.out("  jmp  +")
+        }
+
+        stringVarsWithInitInZp.forEach {
+            val varname = asmgen.asmVariableName(it.name)+"_init_value"
+            outputStringvar(varname, it.value.second, it.value.first)
+        }
+
+        arrayVarsWithInitInZp.forEach {
+            val varname = asmgen.asmVariableName(it.name)+"_init_value"
+            arrayVariable2asm(varname, it.alloc.dt, it.value, null)
+        }
+
+        asmgen.out("""+       tsx
+                    stx  prog8_lib.orig_stackpointer    ; required for sys.exit()                    
+                    ldx  #255       ; init estack ptr
+                    clv
+                    clc""")
+    }
+
+    private class ZpStringWithInitial(
+        val name: List<String>,
+        val alloc: Zeropage.ZpAllocation,
+        val value: Pair<String, Encoding>
+    )
+
+    private class ZpArrayWithInitial(
+        val name: List<String>,
+        val alloc: Zeropage.ZpAllocation,
+        val value: StArray
+    )
+
+    private fun getZpStringVarsWithInitvalue(): Collection<ZpStringWithInitial> {
+        val result = mutableListOf<ZpStringWithInitial>()
+        val vars = allocator.zeropageVars.filter { it.value.dt==DataType.STR }
+        for (variable in vars) {
+            val svar = symboltable.lookup(variable.key) as StStaticVariable        // TODO faster in flat lookup table
+            if(svar.initialStringValue!=null)
+                result.add(ZpStringWithInitial(variable.key, variable.value, svar.initialStringValue!!))
+        }
+        return result
+    }
+
+    private fun getZpArrayVarsWithInitvalue(): Collection<ZpArrayWithInitial> {
+        val result = mutableListOf<ZpArrayWithInitial>()
+        val vars = allocator.zeropageVars.filter { it.value.dt in ArrayDatatypes }
+        for (variable in vars) {
+            val svar = symboltable.lookup(variable.key) as StStaticVariable        // TODO faster in flat lookup table
+            if(svar.initialArrayValue!=null)
+                result.add(ZpArrayWithInitial(variable.key, variable.value, svar.initialArrayValue!!))
+        }
+        return result
+    }
+
+    private fun zeropagevars2asm(varNames: Set<List<String>>) {
+        val zpVariables = allocator.zeropageVars.filter { it.key in varNames }
+        for ((scopedName, zpvar) in zpVariables) {
+            if (scopedName.size == 2 && scopedName[0] == "cx16" && scopedName[1][0] == 'r' && scopedName[1][1].isDigit())
+                continue        // The 16 virtual registers of the cx16 are not actual variables in zp, they're memory mapped
+            asmgen.out("${scopedName.last()} \t= ${zpvar.address} \t; zp ${zpvar.dt}")
+        }
+    }
+
+    private fun nonZpVariables2asm(variables: List<StStaticVariable>) {
+        asmgen.out("")
+        asmgen.out("; non-zeropage variables")
+        val (stringvars, othervars) = variables.partition { it.dt==DataType.STR }
+        stringvars.forEach {
+            outputStringvar(it.name, it.initialStringValue!!.second, it.initialStringValue!!.first)
+        }
+        othervars.sortedBy { it.type }.forEach {
+            staticVariable2asm(it)
+        }
+    }
+
+    private fun staticVariable2asm(variable: StStaticVariable) {
+        val name = variable.name
+        val initialValue: Number =
+            if(variable.initialNumericValue!=null) {
+                if(variable.dt== DataType.FLOAT)
+                    variable.initialNumericValue!!
+                else
+                    variable.initialNumericValue!!.toInt()
+            } else 0
+
+        when (variable.dt) {
+            DataType.UBYTE -> asmgen.out("$name\t.byte  ${initialValue.toHex()}")
+            DataType.BYTE -> asmgen.out("$name\t.char  $initialValue")
+            DataType.UWORD -> asmgen.out("$name\t.word  ${initialValue.toHex()}")
+            DataType.WORD -> asmgen.out("$name\t.sint  $initialValue")
+            DataType.FLOAT -> {
+                if(initialValue==0) {
+                    asmgen.out("$name\t.byte  0,0,0,0,0  ; float")
+                } else {
+                    val floatFill = compTarget.machine.getFloat(initialValue).makeFloatFillAsm()
+                    asmgen.out("$name\t.byte  $floatFill  ; float $initialValue")
+                }
+            }
+            DataType.STR -> {
+                throw AssemblyError("all string vars should have been interned into prog")
+            }
+            in ArrayDatatypes -> arrayVariable2asm(name, variable.dt, variable.initialArrayValue, variable.length)
+            else -> {
+                throw AssemblyError("weird dt")
+            }
+        }
+    }
+
+    private fun arrayVariable2asm(varname: String, dt: DataType, value: StArray?, orNumberOfZeros: Int?) {
+        when(dt) {
+            DataType.ARRAY_UB -> {
+                val data = makeArrayFillDataUnsigned(dt, value, orNumberOfZeros)
+                if (data.size <= 16)
+                    asmgen.out("$varname\t.byte  ${data.joinToString()}")
+                else {
+                    asmgen.out(varname)
+                    for (chunk in data.chunked(16))
+                        asmgen.out("  .byte  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_B -> {
+                val data = makeArrayFillDataSigned(dt, value, orNumberOfZeros)
+                if (data.size <= 16)
+                    asmgen.out("$varname\t.char  ${data.joinToString()}")
+                else {
+                    asmgen.out(varname)
+                    for (chunk in data.chunked(16))
+                        asmgen.out("  .char  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_UW -> {
+                val data = makeArrayFillDataUnsigned(dt, value, orNumberOfZeros)
+                if (data.size <= 16)
+                    asmgen.out("$varname\t.word  ${data.joinToString()}")
+                else {
+                    asmgen.out(varname)
+                    for (chunk in data.chunked(16))
+                        asmgen.out("  .word  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_W -> {
+                val data = makeArrayFillDataSigned(dt, value, orNumberOfZeros)
+                if (data.size <= 16)
+                    asmgen.out("$varname\t.sint  ${data.joinToString()}")
+                else {
+                    asmgen.out(varname)
+                    for (chunk in data.chunked(16))
+                        asmgen.out("  .sint  " + chunk.joinToString())
+                }
+            }
+            DataType.ARRAY_F -> {
+                val array = value ?: zeroFilledArray(orNumberOfZeros!!)
+                val floatFills = array.map {
+                    compTarget.machine.getFloat(it.number!!).makeFloatFillAsm()
+                }
+                asmgen.out(varname)
+                for (f in array.zip(floatFills))
+                    asmgen.out("  .byte  ${f.second}  ; float ${f.first}")
+            }
+            else -> throw AssemblyError("require array dt")
+        }
+    }
+
+    private fun zeroFilledArray(numElts: Int): StArray {
+        val values = mutableListOf<StArrayElement>()
+        repeat(numElts) {
+            values.add(StArrayElement(0.0, null))
+        }
+        return values
+    }
+
+    private fun memdefsAndConsts2asm(memvars: Collection<StMemVar>, consts: Collection<StConstant>) {
+        memvars.forEach {
+            asmgen.out("  ${it.name} = ${it.address.toHex()}")
+        }
+        consts.forEach {
+            if(it.dt==DataType.FLOAT)
+                asmgen.out("  ${it.name} = ${it.value}")
+            else
+                asmgen.out("  ${it.name} = ${it.value.toHex()}")
+        }
+    }
+
+    private fun asmsubs2asm(statements: List<Statement>) {
+        statements
+            .filter { it is Subroutine && it.isAsmSubroutine && it.asmAddress!=null }
+            .forEach { asmsub ->
+                asmsub as Subroutine
+                asmgen.out("  ${asmsub.name} = ${asmsub.asmAddress!!.toHex()}")
+            }
+    }
+
+    private fun outputStringvar(varname: String, encoding: Encoding, value: String) {
+        asmgen.out("$varname\t; $encoding:\"${escape(value).replace("\u0000", "<NULL>")}\"")
+        val bytes = compTarget.encodeString(value, encoding).plus(0.toUByte())
+        val outputBytes = bytes.map { "$" + it.toString(16).padStart(2, '0') }
+        for (chunk in outputBytes.chunked(16))
+            asmgen.out("  .byte  " + chunk.joinToString())
+    }
+
+    private fun makeArrayFillDataUnsigned(dt: DataType, value: StArray?, orNumberOfZeros: Int?): List<String> {
+        val array = value ?: zeroFilledArray(orNumberOfZeros!!)
+        return when (dt) {
+            DataType.ARRAY_UB ->
+                // byte array can never contain pointer-to types, so treat values as all integers
+                array.map {
+                    val number = it.number!!.toInt()
+                    "$"+number.toString(16).padStart(2, '0')
+                }
+            DataType.ARRAY_UW -> array.map {
+                if(it.number!=null) {
+                    "$" + it.number!!.toInt().toString(16).padStart(4, '0')
+                }
+                else if(it.addressOf!=null) {
+                    asmgen.asmSymbolName(it.addressOf!!)
+                }
+                else
+                    throw AssemblyError("weird array elt")
+            }
+            else -> throw AssemblyError("invalid dt")
+        }
+    }
+
+    private fun makeArrayFillDataSigned(dt: DataType, value: StArray?, orNumberOfZeros: Int?): List<String> {
+        val array = value ?: zeroFilledArray(orNumberOfZeros!!)
+        return when (dt) {
+            // byte array can never contain pointer-to types, so treat values as all integers
+            DataType.ARRAY_UB ->
+                array.map {
+                    val number = it.number!!.toInt()
+                    "$"+number.toString(16).padStart(2, '0')
+                }
+            DataType.ARRAY_B ->
+                array.map {
+                    val number = it.number!!.toInt()
+                    val hexnum = number.absoluteValue.toString(16).padStart(2, '0')
+                    if(number>=0)
+                        "$$hexnum"
+                    else
+                        "-$$hexnum"
+                }
+            DataType.ARRAY_UW -> array.map {
+                val number = it.number!!.toInt()
+                "$" + number.toString(16).padStart(4, '0')
+            }
+            DataType.ARRAY_W -> array.map {
+                val number = it.number!!.toInt()
+                val hexnum = number.absoluteValue.toString(16).padStart(4, '0')
+                if(number>=0)
+                    "$$hexnum"
+                else
+                    "-$$hexnum"
+            }
+            else -> throw AssemblyError("invalid dt")
+        }
+    }
+
+}

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

@@ -0,0 +1,137 @@
+package prog8.codegen.cpu6502
+
+import com.github.michaelbull.result.fold
+import com.github.michaelbull.result.onSuccess
+import prog8.code.StNode
+import prog8.code.StNodeType
+import prog8.code.StStaticVariable
+import prog8.code.SymbolTable
+import prog8.code.core.*
+
+
+internal class VariableAllocator(private val symboltable: SymbolTable,
+                                 private val options: CompilationOptions,
+                                 private val errors: IErrorReporter
+) {
+
+    private val zeropage = options.compTarget.machine.zeropage
+    private val memorySlabsInternal = mutableMapOf<String, Pair<UInt, UInt>>()
+    internal val memorySlabs: Map<String, Pair<UInt, UInt>> = memorySlabsInternal
+    internal val globalFloatConsts = mutableMapOf<Double, String>()     // all float values in the entire program (value -> varname)
+    internal val zeropageVars: Map<List<String>, Zeropage.ZpAllocation> = zeropage.allocatedVariables
+
+    init {
+        allocateZeropageVariables()
+    }
+
+    internal fun getMemorySlab(name: String) = memorySlabsInternal[name]
+
+    internal fun allocateMemorySlab(name: String, size: UInt, align: UInt) {
+        memorySlabsInternal[name] = Pair(size, align)
+    }
+
+    internal fun isZpVar(scopedName: List<String>) = scopedName in zeropage.allocatedVariables
+
+    internal fun getFloatAsmConst(number: Double): String {
+        val asmName = globalFloatConsts[number]
+        if(asmName!=null)
+            return asmName
+
+        val newName = "prog8_float_const_${globalFloatConsts.size}"
+        globalFloatConsts[number] = newName
+        return newName
+    }
+
+    /**
+     * Allocate variables into the Zeropage.
+     * The result should be retrieved from the current machine's zeropage object!
+     */
+    private fun allocateZeropageVariables() {
+        if(options.zeropage== ZeropageType.DONTUSE)
+            return
+
+        val allVariables = collectAllVariables(symboltable)
+
+        val numberOfAllocatableVariables = allVariables.size
+        val varsRequiringZp = allVariables.filter { it.zpwish == ZeropageWish.REQUIRE_ZEROPAGE }
+        val varsPreferringZp = allVariables.filter { it.zpwish == ZeropageWish.PREFER_ZEROPAGE }
+        val varsDontCare = allVariables.filter { it.zpwish == ZeropageWish.DONTCARE }
+        val numberOfExplicitNonZpVariables = allVariables.count { it.zpwish == ZeropageWish.NOT_IN_ZEROPAGE }
+        require(varsDontCare.size + varsRequiringZp.size + varsPreferringZp.size + numberOfExplicitNonZpVariables == numberOfAllocatableVariables)
+
+        var numVariablesAllocatedInZP = 0
+        var numberOfNonIntegerVariables = 0
+
+        varsRequiringZp.forEach { variable ->
+            val result = zeropage.allocate(
+                variable.scopedName,
+                variable.dt,
+                variable.length,
+                variable.position,
+                errors
+            )
+            result.fold(
+                success = {
+                    numVariablesAllocatedInZP++
+                },
+                failure = {
+                    errors.err(it.message!!, variable.position)
+                }
+            )
+        }
+
+        if(errors.noErrors()) {
+            varsPreferringZp.forEach { variable ->
+                val result = zeropage.allocate(
+                    variable.scopedName,
+                    variable.dt,
+                    variable.length,
+                    variable.position,
+                    errors
+                )
+                result.onSuccess { numVariablesAllocatedInZP++ }
+                //  no need to check for allocation error, if there is one, just allocate in normal system ram.
+            }
+
+            // try to allocate any other interger variables into the zeropage until it is full.
+            // TODO some form of intelligent priorization? most often used variables first? loopcounter vars first? ...?
+            if(errors.noErrors()) {
+                for (variable in varsDontCare.sortedBy { it.scopedName.size }) {
+                    if(variable.dt in IntegerDatatypes) {
+                        if(zeropage.free.isEmpty()) {
+                            break
+                        } else {
+                            val result = zeropage.allocate(
+                                variable.scopedName,
+                                variable.dt,
+                                variable.length,
+                                variable.position,
+                                errors
+                            )
+                            result.onSuccess { numVariablesAllocatedInZP++ }
+                        }
+                    } else
+                        numberOfNonIntegerVariables++
+                }
+            }
+        }
+
+        println("  number of allocated vars: $numberOfAllocatableVariables")
+        println("  put into zeropage: $numVariablesAllocatedInZP,  non-zp allocatable: ${numberOfNonIntegerVariables+numberOfExplicitNonZpVariables}")
+        println("  zeropage free space: ${zeropage.free.size} bytes")
+    }
+
+    private fun collectAllVariables(st: SymbolTable): Collection<StStaticVariable> {
+        val vars = mutableListOf<StStaticVariable>()
+        fun collect(node: StNode) {
+            for(child in node.children) {
+                if(child.value.type == StNodeType.STATICVAR)
+                    vars.add(child.value as StStaticVariable)
+                else
+                    collect(child.value)
+            }
+        }
+        collect(st)
+        return vars
+    }
+}

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

@@ -1,12 +1,10 @@
-package prog8.compiler.target.cpu6502.codegen.assignment
+package prog8.codegen.cpu6502.assignment
 
 import prog8.ast.Program
-import prog8.ast.base.*
 import prog8.ast.expressions.*
 import prog8.ast.statements.*
-import prog8.compilerinterface.IMemSizer
-import prog8.compiler.target.AssemblyError
-import prog8.compiler.target.cpu6502.codegen.AsmGen
+import prog8.code.core.*
+import prog8.codegen.cpu6502.AsmGen
 
 
 internal enum class TargetStorageKind {
@@ -39,8 +37,8 @@ internal class AsmAssignTarget(val kind: TargetStorageKind,
                                val origAstTarget: AssignTarget? = null
                                )
 {
-    val constMemoryAddress by lazy { memory?.addressExpression?.constValue(program)?.number?.toInt() ?: 0}
-    val constArrayIndexValue by lazy { array?.indexer?.constIndex() }
+    val constMemoryAddress by lazy { memory?.addressExpression?.constValue(program)?.number?.toUInt() ?: 0u}
+    val constArrayIndexValue by lazy { array?.indexer?.constIndex()?.toUInt() }
     val asmVarname: String by lazy {
         if (array == null)
             variableAsmName!!
@@ -56,16 +54,29 @@ internal class AsmAssignTarget(val kind: TargetStorageKind,
     }
 
     companion object {
-        fun fromAstAssignment(assign: Assignment, program: Program, asmgen: AsmGen): AsmAssignTarget = with(assign.target) {
-            val idt = inferType(program)
-            if(!idt.isKnown)
-                throw AssemblyError("unknown dt")
-            val dt = idt.getOr(DataType.UNDEFINED)
-            when {
-                identifier != null -> AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, dt, assign.definingSubroutine, variableAsmName = asmgen.asmVariableName(identifier!!), origAstTarget =  this)
-                arrayindexed != null -> AsmAssignTarget(TargetStorageKind.ARRAY, program, asmgen, dt, assign.definingSubroutine, array = arrayindexed, origAstTarget =  this)
-                memoryAddress != null -> AsmAssignTarget(TargetStorageKind.MEMORY, program, asmgen, dt, assign.definingSubroutine, memory =  memoryAddress, origAstTarget =  this)
-                else -> throw AssemblyError("weird target")
+        fun fromAstAssignment(assign: Assignment, program: Program, asmgen: AsmGen): AsmAssignTarget {
+            with(assign.target) {
+                val idt = inferType(program)
+                val dt = idt.getOrElse { throw AssemblyError("unknown dt") }
+                when {
+                    identifier != null -> {
+                        val parameter = identifier!!.targetVarDecl(program)?.subroutineParameter
+                        if (parameter!=null) {
+                            val sub = parameter.definingSubroutine!!
+                            if (sub.isAsmSubroutine) {
+                                val reg = sub.asmParameterRegisters[sub.parameters.indexOf(parameter)]
+                                if(reg.statusflag!=null)
+                                    throw AssemblyError("can't assign value to processor statusflag directly")
+                                else
+                                    return AsmAssignTarget(TargetStorageKind.REGISTER, program, asmgen, dt, assign.definingSubroutine, register=reg.registerOrPair, origAstTarget = this)
+                            }
+                        }
+                        return AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, dt, assign.definingSubroutine, variableAsmName = asmgen.asmVariableName(identifier!!), origAstTarget =  this)
+                    }
+                    arrayindexed != null -> return AsmAssignTarget(TargetStorageKind.ARRAY, program, asmgen, dt, assign.definingSubroutine, array = arrayindexed, origAstTarget =  this)
+                    memoryAddress != null -> return AsmAssignTarget(TargetStorageKind.MEMORY, program, asmgen, dt, assign.definingSubroutine, memory =  memoryAddress, origAstTarget =  this)
+                    else -> throw AssemblyError("weird target")
+                }
             }
         }
 
@@ -107,12 +118,12 @@ internal class AsmAssignSource(val kind: SourceStorageKind,
                                val array: ArrayIndexedExpression? = null,
                                val memory: DirectMemoryRead? = null,
                                val register: RegisterOrPair? = null,
-                               val number: NumericLiteralValue? = null,
+                               val number: NumericLiteral? = null,
                                val expression: Expression? = null
 )
 {
-    val constMemoryAddress by lazy { memory?.addressExpression?.constValue(program)?.number?.toInt() ?: 0}
-    val constArrayIndexValue by lazy { array?.indexer?.constIndex() }
+    val constMemoryAddress by lazy { memory?.addressExpression?.constValue(program)?.number?.toUInt() ?: 0u}
+    val constArrayIndexValue by lazy { array?.indexer?.constIndex()?.toUInt() }
 
     val asmVarname: String
         get() = if(array==null)
@@ -129,10 +140,13 @@ internal class AsmAssignSource(val kind: SourceStorageKind,
                 return AsmAssignSource(SourceStorageKind.LITERALNUMBER, program, asmgen, cv.type, number = cv)
 
             return when(value) {
-                is NumericLiteralValue -> AsmAssignSource(SourceStorageKind.LITERALNUMBER, program, asmgen, value.type, number = cv)
-                is StringLiteralValue -> throw AssemblyError("string literal value should not occur anymore for asm generation")
-                is ArrayLiteralValue -> throw AssemblyError("array literal value should not occur anymore for asm generation")
+                is NumericLiteral -> throw AssemblyError("should have been constant value")
+                is StringLiteral -> throw AssemblyError("string literal value should not occur anymore for asm generation")
+                is ArrayLiteral -> throw AssemblyError("array literal value should not occur anymore for asm generation")
                 is IdentifierReference -> {
+                    val parameter = value.targetVarDecl(program)?.subroutineParameter
+                    if(parameter!=null && parameter.definingSubroutine!!.isAsmSubroutine)
+                        throw AssemblyError("can't assign from a asmsub register parameter $value ${value.position}")
                     val dt = value.inferType(program).getOr(DataType.UNDEFINED)
                     val varName=asmgen.asmVariableName(value)
                     // special case: "cx16.r[0-15]" are 16-bits virtual registers of the commander X16 system
@@ -148,33 +162,23 @@ internal class AsmAssignSource(val kind: SourceStorageKind,
                     AsmAssignSource(SourceStorageKind.MEMORY, program, asmgen, DataType.UBYTE, memory = value)
                 }
                 is ArrayIndexedExpression -> {
-                    val dt = value.inferType(program).getOr(DataType.UNDEFINED)
+                    val dt = value.inferType(program).getOrElse { throw AssemblyError("unknown dt") }
                     AsmAssignSource(SourceStorageKind.ARRAY, program, asmgen, dt, array = value)
                 }
-                is FunctionCall -> {
-                    when (val sub = value.target.targetStatement(program)) {
-                        is Subroutine -> {
-                            val returnType = sub.returntypes.zip(sub.asmReturnvaluesRegisters).firstOrNull { rr -> rr.second.registerOrPair != null || rr.second.statusflag!=null }?.first
-                                    ?: throw AssemblyError("can't translate zero return values in assignment")
+                is BuiltinFunctionCall -> {
+                    val returnType = value.inferType(program)
+                    AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, returnType.getOrElse { throw AssemblyError("unknown dt") }, expression = value)
+                }
+                is FunctionCallExpression -> {
+                    val sub = value.target.targetSubroutine(program)!!
+                    val returnType = sub.returntypes.zip(sub.asmReturnvaluesRegisters).firstOrNull { rr -> rr.second.registerOrPair != null || rr.second.statusflag!=null }?.first
+                            ?: throw AssemblyError("can't translate zero return values in assignment")
 
-                            AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, returnType, expression = value)
-                        }
-                        is BuiltinFunctionStatementPlaceholder -> {
-                            val returnType = value.inferType(program)
-                            if(!returnType.isKnown)
-                                throw AssemblyError("unknown dt")
-                            AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, returnType.getOr(DataType.UNDEFINED), expression = value)
-                        }
-                        else -> {
-                            throw AssemblyError("weird call")
-                        }
-                    }
+                    AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, returnType, expression = value)
                 }
                 else -> {
-                    val dt = value.inferType(program)
-                    if(!dt.isKnown)
-                        throw AssemblyError("unknown dt")
-                    AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, dt.getOr(DataType.UNDEFINED), expression = value)
+                    val returnType = value.inferType(program)
+                    AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, returnType.getOrElse { throw AssemblyError("unknown dt") }, expression = value)
                 }
             }
         }
@@ -209,7 +213,7 @@ internal class AsmAssignment(val source: AsmAssignSource,
         if(target.register !in arrayOf(RegisterOrPair.XY, RegisterOrPair.AX, RegisterOrPair.AY))
             require(source.datatype != DataType.UNDEFINED) { "must not be placeholder/undefined datatype" }
             require(memsizer.memorySize(source.datatype) <= memsizer.memorySize(target.datatype)) {
-                "source storage size must be less or equal to target datatype storage size"
+                "source dt size must be less or equal to target dt size at $position"
             }
     }
 }

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

@@ -1,23 +1,18 @@
-package prog8.compiler.target.cpu6502.codegen.assignment
+package prog8.codegen.cpu6502.assignment
 
 import prog8.ast.Program
-import prog8.ast.base.*
 import prog8.ast.expressions.*
 import prog8.ast.statements.*
-import prog8.ast.toHex
-import prog8.compiler.target.AssemblyError
-import prog8.compiler.target.cpu6502.codegen.AsmGen
-import prog8.compiler.target.cpu6502.codegen.ExpressionsAsmGen
-import prog8.compilerinterface.BuiltinFunctions
-import prog8.compilerinterface.CpuType
-import prog8.compilerinterface.builtinFunctionReturnType
+import prog8.code.core.*
+import prog8.codegen.cpu6502.AsmGen
+import prog8.codegen.cpu6502.VariableAllocator
+import prog8.compiler.builtinFunctionReturnType
 
 
-internal class AssignmentAsmGen(private val program: Program, private val asmgen: AsmGen,
-                                private val exprAsmgen: ExpressionsAsmGen
-) {
-
-    private val augmentableAsmGen = AugmentableAssignmentAsmGen(program, this, exprAsmgen, asmgen)
+internal class AssignmentAsmGen(private val program: Program, 
+                                private val asmgen: AsmGen, 
+                                private val allocator: VariableAllocator) {
+    private val augmentableAsmGen = AugmentableAssignmentAsmGen(program, this, asmgen, allocator)
 
     fun translate(assignment: Assignment) {
         val target = AsmAssignTarget.fromAstAssignment(assignment, program, asmgen)
@@ -32,6 +27,13 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
             translateNormalAssignment(assign)
     }
 
+    internal fun virtualRegsToVariables(origtarget: AsmAssignTarget): AsmAssignTarget {
+        return if(origtarget.kind==TargetStorageKind.REGISTER && origtarget.register in Cx16VirtualRegisters) {
+            AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, origtarget.datatype, origtarget.scope,
+                variableAsmName = "cx16.${origtarget.register!!.name.lowercase()}", origAstTarget = origtarget.origAstTarget)
+        } else origtarget
+    }
+
     fun translateNormalAssignment(assign: AsmAssignment) {
         if(assign.isAugmentable) {
             augmentableAsmGen.translate(assign)
@@ -43,9 +45,9 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                 // simple case: assign a constant number
                 val num = assign.source.number!!.number
                 when (assign.target.datatype) {
-                    DataType.UBYTE, DataType.BYTE -> assignConstantByte(assign.target, num.toShort())
+                    DataType.UBYTE, DataType.BYTE -> assignConstantByte(assign.target, num.toInt())
                     DataType.UWORD, DataType.WORD -> assignConstantWord(assign.target, num.toInt())
-                    DataType.FLOAT -> assignConstantFloat(assign.target, num.toDouble())
+                    DataType.FLOAT -> assignConstantFloat(assign.target, num)
                     else -> throw AssemblyError("weird numval type")
                 }
             }
@@ -84,7 +86,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                             assignRegisterpairWord(assign.target, RegisterOrPair.AY)
                         }
                         DataType.FLOAT -> {
-                            asmgen.out("  lda  #<$arrayVarName+$indexValue |  ldy  #>$arrayVarName+$indexValue")
+                            asmgen.out("  lda  #<($arrayVarName+$indexValue) |  ldy  #>($arrayVarName+$indexValue)")
                             assignFloatFromAY(assign.target)
                         }
                         else ->
@@ -121,17 +123,14 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
             SourceStorageKind.MEMORY -> {
                 fun assignViaExprEval(expression: Expression) {
                     assignExpressionToVariable(expression, "P8ZP_SCRATCH_W2", DataType.UWORD, assign.target.scope)
-                    if (asmgen.isTargetCpu(CpuType.CPU65c02))
-                        asmgen.out("  lda  (P8ZP_SCRATCH_W2)")
-                    else
-                        asmgen.out("  ldy  #0 |  lda  (P8ZP_SCRATCH_W2),y")
+                    asmgen.loadAFromZpPointerVar("P8ZP_SCRATCH_W2")
                     assignRegisterByte(assign.target, CpuRegister.A)
                 }
 
                 val value = assign.source.memory!!
                 when (value.addressExpression) {
-                    is NumericLiteralValue -> {
-                        val address = (value.addressExpression as NumericLiteralValue).number.toInt()
+                    is NumericLiteral -> {
+                        val address = (value.addressExpression as NumericLiteral).number.toUInt()
                         assignMemoryByte(assign.target, address, null)
                     }
                     is IdentifierReference -> {
@@ -148,139 +147,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                 }
             }
             SourceStorageKind.EXPRESSION -> {
-                when(val value = assign.source.expression!!) {
-                    is AddressOf -> {
-                        val sourceName = asmgen.asmSymbolName(value.identifier)
-                        assignAddressOf(assign.target, sourceName)
-                    }
-                    is NumericLiteralValue -> throw AssemblyError("source kind should have been literalnumber")
-                    is IdentifierReference -> throw AssemblyError("source kind should have been variable")
-                    is ArrayIndexedExpression -> throw AssemblyError("source kind should have been array")
-                    is DirectMemoryRead -> throw AssemblyError("source kind should have been memory")
-                    is TypecastExpression -> assignTypeCastedValue(assign.target, value.type, value.expression, value)
-                    is FunctionCall -> {
-                        when (val sub = value.target.targetStatement(program)) {
-                            is Subroutine -> {
-                                asmgen.saveXbeforeCall(value)
-                                asmgen.translateFunctionCall(value)
-                                val returnValue = sub.returntypes.zip(sub.asmReturnvaluesRegisters).singleOrNull { it.second.registerOrPair!=null } ?:
-                                    sub.returntypes.zip(sub.asmReturnvaluesRegisters).single { it.second.statusflag!=null }
-                                when (returnValue.first) {
-                                    DataType.STR -> {
-                                        asmgen.restoreXafterCall(value)
-                                        when(assign.target.datatype) {
-                                            DataType.UWORD -> {
-                                                // assign the address of the string result value
-                                                assignRegisterpairWord(assign.target, RegisterOrPair.AY)
-                                            }
-                                            DataType.STR, DataType.ARRAY_UB, DataType.ARRAY_B -> {
-                                                // copy the actual string result into the target string variable
-                                                asmgen.out("""
-                                                    pha
-                                                    lda  #<${assign.target.asmVarname}
-                                                    sta  P8ZP_SCRATCH_W1
-                                                    lda  #>${assign.target.asmVarname}
-                                                    sta  P8ZP_SCRATCH_W1+1
-                                                    pla
-                                                    jsr  prog8_lib.strcpy""")
-                                            }
-                                            else -> throw AssemblyError("weird target dt")
-                                        }
-                                    }
-                                    DataType.FLOAT -> {
-                                        // float result from function sits in FAC1
-                                        asmgen.restoreXafterCall(value)
-                                        assignFAC1float(assign.target)
-                                    }
-                                    else -> {
-                                        // do NOT restore X register before assigning the result values first
-                                        when (returnValue.second.registerOrPair) {
-                                            RegisterOrPair.A -> assignRegisterByte(assign.target, CpuRegister.A)
-                                            RegisterOrPair.X -> assignRegisterByte(assign.target, CpuRegister.X)
-                                            RegisterOrPair.Y -> assignRegisterByte(assign.target, CpuRegister.Y)
-                                            RegisterOrPair.AX -> assignRegisterpairWord(assign.target, RegisterOrPair.AX)
-                                            RegisterOrPair.AY -> assignRegisterpairWord(assign.target, RegisterOrPair.AY)
-                                            RegisterOrPair.XY -> assignRegisterpairWord(assign.target, RegisterOrPair.XY)
-                                            else -> {
-                                                val sflag = returnValue.second.statusflag
-                                                if(sflag!=null)
-                                                    assignStatusFlagByte(assign.target, sflag)
-                                                else
-                                                    throw AssemblyError("should be just one register byte result value")
-                                            }
-                                        }
-                                        // we've processed the result value in the X register by now, so it's now finally safe to restore it
-                                        asmgen.restoreXafterCall(value)
-                                    }
-                                }
-                            }
-                            is BuiltinFunctionStatementPlaceholder -> {
-                                val signature = BuiltinFunctions.getValue(sub.name)
-                                asmgen.translateBuiltinFunctionCallExpression(value, signature, false, assign.target.register)
-                                if(assign.target.register==null) {
-                                    // still need to assign the result to the target variable/etc.
-                                    val returntype = builtinFunctionReturnType(sub.name, value.args, program)
-                                    if(!returntype.isKnown)
-                                        throw AssemblyError("unknown dt")
-                                    when(returntype.getOr(DataType.UNDEFINED)) {
-                                        in ByteDatatypes -> assignRegisterByte(assign.target, CpuRegister.A)            // function's byte result is in A
-                                        in WordDatatypes -> assignRegisterpairWord(assign.target, RegisterOrPair.AY)    // function's word result is in AY
-                                        DataType.STR -> {
-                                            when (assign.target.datatype) {
-                                                DataType.STR -> {
-                                                    asmgen.out("""
-                                                        pha
-                                                        lda  #<${assign.target.asmVarname}
-                                                        sta  P8ZP_SCRATCH_W1
-                                                        lda  #>${assign.target.asmVarname}
-                                                        sta  P8ZP_SCRATCH_W1+1
-                                                        pla
-                                                        jsr  prog8_lib.strcpy""")
-                                                }
-                                                DataType.UWORD -> assignRegisterpairWord(assign.target, RegisterOrPair.AY)
-                                                else -> throw AssemblyError("str return value type mismatch with target")
-                                            }
-                                        }
-                                        DataType.FLOAT -> {
-                                            // float result from function sits in FAC1
-                                            assignFAC1float(assign.target)
-                                        }
-                                        else -> throw AssemblyError("weird result type")
-                                    }
-                                }
-                            }
-                            else -> {
-                                throw AssemblyError("weird func call")
-                            }
-                        }
-                    }
-                    is PrefixExpression -> {
-                        // first assign the value to the target then apply the operator in place on the target.
-                        translateNormalAssignment(AsmAssignment(
-                            AsmAssignSource.fromAstSource(value.expression, program, asmgen),
-                            assign.target,
-                            false, program.memsizer, assign.position
-                        ))
-                        when(value.operator) {
-                            "+" -> {}
-                            "-" -> augmentableAsmGen.inplaceNegate(assign.target, assign.target.datatype)
-                            "~" -> augmentableAsmGen.inplaceInvert(assign.target, assign.target.datatype)
-                            "not" -> augmentableAsmGen.inplaceBooleanNot(assign.target, assign.target.datatype)
-                            else -> throw AssemblyError("invalid prefix operator")
-                        }
-                    }
-                    else -> {
-                        // Everything else just evaluate via the stack.
-                        // (we can't use the assignment helper functions (assignExpressionTo...) to do it via registers here,
-                        // because the code here is the implementation of exactly that...)
-                        // TODO FIX THIS... by using a temp var? so that it becomes augmentable assignment expression?
-                        asmgen.translateExpression(value)
-                        if (assign.target.datatype in WordDatatypes && assign.source.datatype in ByteDatatypes)
-                            asmgen.signExtendStackLsb(assign.source.datatype)
-                        if(assign.target.kind!=TargetStorageKind.STACK || assign.target.datatype != assign.source.datatype)
-                            assignStackValue(assign.target)
-                    }
-                }
+                assignExpression(assign)
             }
             SourceStorageKind.REGISTER -> {
                 asmgen.assignRegister(assign.source.register!!, assign.target)
@@ -292,6 +159,266 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
         }
     }
 
+    private fun assignExpression(assign: AsmAssignment) {
+        when(val value = assign.source.expression!!) {
+            is AddressOf -> {
+                val sourceName = asmgen.asmSymbolName(value.identifier)
+                assignAddressOf(assign.target, sourceName)
+            }
+            is NumericLiteral -> throw AssemblyError("source kind should have been literalnumber")
+            is IdentifierReference -> throw AssemblyError("source kind should have been variable")
+            is ArrayIndexedExpression -> throw AssemblyError("source kind should have been array")
+            is DirectMemoryRead -> throw AssemblyError("source kind should have been memory")
+            is TypecastExpression -> assignTypeCastedValue(assign.target, value.type, value.expression, value)
+            is FunctionCallExpression -> {
+                val sub = value.target.targetSubroutine(program)!!
+                asmgen.saveXbeforeCall(value)
+                asmgen.translateFunctionCall(value, true)
+                val returnValue = sub.returntypes.zip(sub.asmReturnvaluesRegisters).singleOrNull { it.second.registerOrPair!=null } ?:
+                sub.returntypes.zip(sub.asmReturnvaluesRegisters).single { it.second.statusflag!=null }
+                when (returnValue.first) {
+                    DataType.STR -> {
+                        asmgen.restoreXafterCall(value)
+                        when(assign.target.datatype) {
+                            DataType.UWORD -> {
+                                // assign the address of the string result value
+                                assignRegisterpairWord(assign.target, RegisterOrPair.AY)
+                            }
+                            DataType.STR, DataType.ARRAY_UB, DataType.ARRAY_B -> {
+                                // copy the actual string result into the target string variable
+                                asmgen.out("""
+                                            pha
+                                            lda  #<${assign.target.asmVarname}
+                                            sta  P8ZP_SCRATCH_W1
+                                            lda  #>${assign.target.asmVarname}
+                                            sta  P8ZP_SCRATCH_W1+1
+                                            pla
+                                            jsr  prog8_lib.strcpy""")
+                            }
+                            else -> throw AssemblyError("weird target dt")
+                        }
+                    }
+                    DataType.FLOAT -> {
+                        // float result from function sits in FAC1
+                        asmgen.restoreXafterCall(value)
+                        assignFAC1float(assign.target)
+                    }
+                    else -> {
+                        // do NOT restore X register before assigning the result values first
+                        when (returnValue.second.registerOrPair) {
+                            RegisterOrPair.A -> assignRegisterByte(assign.target, CpuRegister.A)
+                            RegisterOrPair.X -> assignRegisterByte(assign.target, CpuRegister.X)
+                            RegisterOrPair.Y -> assignRegisterByte(assign.target, CpuRegister.Y)
+                            RegisterOrPair.AX -> assignRegisterpairWord(assign.target, RegisterOrPair.AX)
+                            RegisterOrPair.AY -> assignRegisterpairWord(assign.target, RegisterOrPair.AY)
+                            RegisterOrPair.XY -> assignRegisterpairWord(assign.target, RegisterOrPair.XY)
+                            else -> {
+                                val sflag = returnValue.second.statusflag
+                                if(sflag!=null)
+                                    assignStatusFlagByte(assign.target, sflag)
+                                else
+                                    throw AssemblyError("should be just one register byte result value")
+                            }
+                        }
+                        // we've processed the result value in the X register by now, so it's now finally safe to restore it
+                        asmgen.restoreXafterCall(value)
+                    }
+                }
+            }
+            is BuiltinFunctionCall -> {
+                asmgen.translateBuiltinFunctionCallExpression(value, false, assign.target.register)
+                if(assign.target.register==null) {
+                    // still need to assign the result to the target variable/etc.
+                    val returntype = builtinFunctionReturnType(value.name, value.args, program)
+                    if(!returntype.isKnown)
+                        throw AssemblyError("unknown dt")
+                    when(returntype.getOr(DataType.UNDEFINED)) {
+                        in ByteDatatypes -> assignRegisterByte(assign.target, CpuRegister.A)            // function's byte result is in A
+                        in WordDatatypes -> assignRegisterpairWord(assign.target, RegisterOrPair.AY)    // function's word result is in AY
+                        DataType.STR -> {
+                            when (assign.target.datatype) {
+                                DataType.STR -> {
+                                    asmgen.out("""
+                                                        pha
+                                                        lda  #<${assign.target.asmVarname}
+                                                        sta  P8ZP_SCRATCH_W1
+                                                        lda  #>${assign.target.asmVarname}
+                                                        sta  P8ZP_SCRATCH_W1+1
+                                                        pla
+                                                        jsr  prog8_lib.strcpy""")
+                                }
+                                DataType.UWORD -> assignRegisterpairWord(assign.target, RegisterOrPair.AY)
+                                else -> throw AssemblyError("str return value type mismatch with target")
+                            }
+                        }
+                        DataType.FLOAT -> {
+                            // float result from function sits in FAC1
+                            assignFAC1float(assign.target)
+                        }
+                        else -> throw AssemblyError("weird result type")
+                    }
+                }
+            }
+            is PrefixExpression -> {
+                // first assign the value to the target then apply the operator in place on the target.
+                translateNormalAssignment(AsmAssignment(
+                    AsmAssignSource.fromAstSource(value.expression, program, asmgen),
+                    assign.target,
+                    false, program.memsizer, assign.position
+                ))
+                val target = virtualRegsToVariables(assign.target)
+                when(value.operator) {
+                    "+" -> {}
+                    "-" -> augmentableAsmGen.inplaceNegate(target, target.datatype)
+                    "~" -> augmentableAsmGen.inplaceInvert(target, target.datatype)
+                    "not" -> augmentableAsmGen.inplaceBooleanNot(target, target.datatype)
+                    else -> throw AssemblyError("invalid prefix operator")
+                }
+            }
+            is ContainmentCheck -> {
+                containmentCheckIntoA(value)
+                assignRegisterByte(assign.target, CpuRegister.A)
+            }
+            is PipeExpression -> {
+                asmgen.translatePipeExpression(value.source, value.segments, value, false, false)
+                val resultDt = value.inferType(program)
+                val register =
+                    if(resultDt.isBytes) RegisterOrPair.A
+                    else if(resultDt.isWords) RegisterOrPair.AY
+                    else if(resultDt istype DataType.FLOAT) RegisterOrPair.FAC1
+                    else throw AssemblyError("invalid dt")
+                asmgen.assignRegister(register, assign.target)
+            }
+            is BinaryExpression -> {
+                if(value.operator in ComparisonOperators) {
+                    // TODO real optimized code for comparison expressions that yield a boolean result value
+                    assignConstantByte(assign.target, 0)
+                    val origTarget = assign.target.origAstTarget
+                    if(origTarget!=null) {
+                        val assignTrue = AnonymousScope(mutableListOf(
+                            Assignment(origTarget, NumericLiteral.fromBoolean(true, assign.position), AssignmentOrigin.ASMGEN, assign.position)
+                        ), assign.position)
+                        val assignFalse = AnonymousScope(mutableListOf(), assign.position)
+                        val ifelse = IfElse(value.copy(), assignTrue, assignFalse, assign.position)
+                        ifelse.linkParents(value)
+                        asmgen.translate(ifelse)
+                    }
+                    else {
+                        // no orig ast assign target so can't use the workaround, so fallback to stack eval
+                        fallbackToStackEval(assign)
+                    }
+                } else {
+                    // All remaining binary expressions just evaluate via the stack for now.
+                    // (we can't use the assignment helper functions (assignExpressionTo...) to do it via registers here,
+                    // because the code here is the implementation of exactly that...)
+                    fallbackToStackEval(assign)
+                }
+            }
+            else -> throw AssemblyError("weird assignment value type $value")
+        }
+    }
+
+    private fun fallbackToStackEval(assign: AsmAssignment) {
+        // TODO DON'T STACK-EVAL... perhaps by using a temp var? so that it becomes augmentable assignment expression?
+        //      or don't try to solve it here in this one case and rather rewrite the whole stack based value evaluation.
+        // this routine is called for assigning a binaryexpression value:
+        // - if it's a boolean comparison expression and the workaround isn't possible (no origTarget ast node)
+        // - for all other binary expressions.
+        asmgen.translateExpression(assign.source.expression!!)
+        if (assign.target.datatype in WordDatatypes && assign.source.datatype in ByteDatatypes)
+            asmgen.signExtendStackLsb(assign.source.datatype)
+        if (assign.target.kind != TargetStorageKind.STACK || assign.target.datatype != assign.source.datatype)
+            assignStackValue(assign.target)
+    }
+
+    private fun containmentCheckIntoA(containment: ContainmentCheck) {
+        val elementDt = containment.element.inferType(program)
+        val variable = (containment.iterable as? IdentifierReference)?.targetVarDecl(program)
+            ?: throw AssemblyError("invalid containment iterable type")
+
+        if(elementDt istype DataType.FLOAT)
+            throw AssemblyError("containment check of floats not supported")
+        if(variable.origin!=VarDeclOrigin.USERCODE) {
+            when(variable.datatype) {
+                DataType.STR -> {
+                    require(elementDt.isBytes)
+                    val stringVal = variable.value as StringLiteral
+                    val varname = asmgen.asmVariableName(containment.iterable as IdentifierReference)
+                    assignExpressionToRegister(containment.element, RegisterOrPair.A, elementDt istype DataType.BYTE)
+                    asmgen.saveRegisterLocal(CpuRegister.A, containment.definingSubroutine!!)
+                    assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W1"), varname)
+                    asmgen.restoreRegisterLocal(CpuRegister.A)
+                    asmgen.out("  ldy  #${stringVal.value.length}")
+                    asmgen.out("  jsr  prog8_lib.containment_bytearray")
+                    return
+                }
+                DataType.ARRAY_F -> {
+                    // require(elementDt istype DataType.FLOAT)
+                    throw AssemblyError("containment check of floats not supported")
+                }
+                in ArrayDatatypes -> {
+                    require(elementDt.isInteger)
+                    val arrayVal = variable.value as ArrayLiteral
+                    val dt = elementDt.getOr(DataType.UNDEFINED)
+                    val varname = asmgen.asmVariableName(containment.iterable as IdentifierReference)
+                    when(dt) {
+                        in ByteDatatypes -> {
+                            assignExpressionToRegister(containment.element, RegisterOrPair.A, elementDt istype DataType.BYTE)
+                            asmgen.saveRegisterLocal(CpuRegister.A, containment.definingSubroutine!!)
+                            assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W1"), varname)
+                            asmgen.restoreRegisterLocal(CpuRegister.A)
+                            asmgen.out("  ldy  #${arrayVal.value.size}")
+                            asmgen.out("  jsr  prog8_lib.containment_bytearray")
+                        }
+                        in WordDatatypes -> {
+                            assignExpressionToVariable(containment.element, "P8ZP_SCRATCH_W1", elementDt.getOr(DataType.UNDEFINED), containment.definingSubroutine)
+                            assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W2"), varname)
+                            asmgen.out("  ldy  #${arrayVal.value.size}")
+                            asmgen.out("  jsr  prog8_lib.containment_wordarray")
+                        }
+                        else -> throw AssemblyError("invalid dt")
+                    }
+                    return
+                }
+                else -> throw AssemblyError("invalid dt")
+            }
+        }
+        val varname = asmgen.asmVariableName(containment.iterable as IdentifierReference)
+        when(variable.datatype) {
+            DataType.STR -> {
+                // use subroutine
+                assignExpressionToRegister(containment.element, RegisterOrPair.A, elementDt istype DataType.BYTE)
+                asmgen.saveRegisterLocal(CpuRegister.A, containment.definingSubroutine!!)
+                assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W1"), varname)
+                asmgen.restoreRegisterLocal(CpuRegister.A)
+                val stringVal = variable.value as StringLiteral
+                asmgen.out("  ldy  #${stringVal.value.length}")
+                asmgen.out("  jsr  prog8_lib.containment_bytearray")
+                return
+            }
+            DataType.ARRAY_F -> throw AssemblyError("containment check of floats not supported")
+            DataType.ARRAY_B, DataType.ARRAY_UB -> {
+                val arrayVal = variable.value as ArrayLiteral
+                assignExpressionToRegister(containment.element, RegisterOrPair.A, elementDt istype DataType.BYTE)
+                asmgen.saveRegisterLocal(CpuRegister.A, containment.definingSubroutine!!)
+                assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W1"), varname)
+                asmgen.restoreRegisterLocal(CpuRegister.A)
+                asmgen.out("  ldy  #${arrayVal.value.size}")
+                asmgen.out("  jsr  prog8_lib.containment_bytearray")
+                return
+            }
+            DataType.ARRAY_W, DataType.ARRAY_UW -> {
+                val arrayVal = variable.value as ArrayLiteral
+                assignExpressionToVariable(containment.element, "P8ZP_SCRATCH_W1", elementDt.getOr(DataType.UNDEFINED), containment.definingSubroutine)
+                assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W2"), varname)
+                asmgen.out("  ldy  #${arrayVal.value.size}")
+                asmgen.out("  jsr  prog8_lib.containment_wordarray")
+                return
+            }
+            else -> throw AssemblyError("invalid dt")
+        }
+    }
+
     private fun assignStatusFlagByte(target: AsmAssignTarget, statusflag: Statusflag) {
         when(statusflag) {
             Statusflag.Pc -> {
@@ -312,9 +439,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
 
     private fun assignTypeCastedValue(target: AsmAssignTarget, targetDt: DataType, value: Expression, origTypeCastExpression: TypecastExpression) {
         val valueIDt = value.inferType(program)
-        if(!valueIDt.isKnown)
-            throw AssemblyError("unknown dt")
-        val valueDt = valueIDt.getOr(DataType.UNDEFINED)
+        val valueDt = valueIDt.getOrElse { throw AssemblyError("unknown dt") }
         if(valueDt==targetDt)
             throw AssemblyError("type cast to identical dt should have been removed")
 
@@ -336,16 +461,13 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
 
                     fun assignViaExprEval(addressExpression: Expression) {
                         asmgen.assignExpressionToVariable(addressExpression, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
-                        if (asmgen.isTargetCpu(CpuType.CPU65c02))
-                            asmgen.out("  lda  (P8ZP_SCRATCH_W2)")
-                        else
-                            asmgen.out("  ldy  #0 |  lda  (P8ZP_SCRATCH_W2),y")
+                        asmgen.loadAFromZpPointerVar("P8ZP_SCRATCH_W2")
                         assignRegisterByte(target, CpuRegister.A)
                     }
 
                     when (value.addressExpression) {
-                        is NumericLiteralValue -> {
-                            val address = (value.addressExpression as NumericLiteralValue).number.toInt()
+                        is NumericLiteral -> {
+                            val address = (value.addressExpression as NumericLiteral).number.toUInt()
                             assignMemoryByteIntoWord(target, address, null)
                             return
                         }
@@ -367,7 +489,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                     }
                 }
             }
-            is NumericLiteralValue -> throw AssemblyError("a cast of a literal value should have been const-folded away")
+            is NumericLiteral -> throw AssemblyError("a cast of a literal value should have been const-folded away")
             else -> {}
         }
 
@@ -445,13 +567,44 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
             }
         }
 
-        // No more special optmized cases yet. Do the rest via more complex evaluation
-        // note: cannot use assignTypeCastedValue because that is ourselves :P
-        asmgen.assignExpressionTo(origTypeCastExpression, target)
+        if(target.kind==TargetStorageKind.REGISTER) {
+            assignExpressionToRegister(value, target.register!!, targetDt==DataType.BYTE || targetDt==DataType.WORD)
+            return
+        }
+
+        if(targetDt==DataType.FLOAT && (target.register==RegisterOrPair.FAC1 || target.register==RegisterOrPair.FAC2)) {
+            when(valueDt) {
+                DataType.UBYTE -> {
+                    assignExpressionToRegister(value, RegisterOrPair.Y, false)
+                    asmgen.out("  jsr  floats.FREADUY")
+                }
+                DataType.BYTE -> {
+                    assignExpressionToRegister(value, RegisterOrPair.A, true)
+                    asmgen.out("  jsr  floats.FREADSA")
+                }
+                DataType.UWORD -> {
+                    assignExpressionToRegister(value, RegisterOrPair.AY, false)
+                    asmgen.out("  jsr  floats.GIVUAYFAY")
+                }
+                DataType.WORD -> {
+                    assignExpressionToRegister(value, RegisterOrPair.AY, true)
+                    asmgen.out("  jsr  floats.GIVAYFAY")
+                }
+                else -> throw AssemblyError("invalid dt")
+            }
+            if(target.register==RegisterOrPair.FAC2) {
+                asmgen.out("  jsr floats.MOVEF")
+            }
+        } else {
+            // No more special optmized cases yet. Do the rest via more complex evaluation
+            // note: cannot use assignTypeCastedValue because that is ourselves :P
+            // NOTE: THIS MAY TURN INTO A STACK OVERFLOW ERROR IF IT CAN'T SIMPLIFY THE TYPECAST..... :-/
+            asmgen.assignExpressionTo(origTypeCastExpression, target)
+        }
     }
 
     private fun assignCastViaLsbFunc(value: Expression, target: AsmAssignTarget) {
-        val lsb = FunctionCall(IdentifierReference(listOf("lsb"), value.position), mutableListOf(value), value.position)
+        val lsb = BuiltinFunctionCall(IdentifierReference(listOf("lsb"), value.position), mutableListOf(value), value.position)
         lsb.linkParents(value.parent)
         val src = AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, DataType.UBYTE, expression = lsb)
         val assign = AsmAssignment(src, target, false, program.memsizer, value.position)
@@ -779,7 +932,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
             }
             TargetStorageKind.ARRAY -> {
                 if(target.constArrayIndexValue!=null) {
-                    val scaledIdx = target.constArrayIndexValue!! * program.memsizer.memorySize(target.datatype)
+                    val scaledIdx = target.constArrayIndexValue!! * program.memsizer.memorySize(target.datatype).toUInt()
                     when(target.datatype) {
                         in ByteDatatypes -> {
                             asmgen.out(" inx | lda  P8ESTACK_LO,x  | sta  ${target.asmVarname}+$scaledIdx")
@@ -795,8 +948,8 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                         }
                         DataType.FLOAT -> {
                             asmgen.out("""
-                                lda  #<${target.asmVarname}+$scaledIdx
-                                ldy  #>${target.asmVarname}+$scaledIdx
+                                lda  #<(${target.asmVarname}+$scaledIdx)
+                                ldy  #>(${target.asmVarname}+$scaledIdx)
                                 jsr  floats.pop_float
                             """)
                         }
@@ -989,7 +1142,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
             TargetStorageKind.ARRAY -> {
                 target.array!!
                 if(target.constArrayIndexValue!=null) {
-                    val scaledIdx = target.constArrayIndexValue!! * program.memsizer.memorySize(target.datatype)
+                    val scaledIdx = target.constArrayIndexValue!! * program.memsizer.memorySize(target.datatype).toUInt()
                     when(target.datatype) {
                         in ByteDatatypes -> {
                             asmgen.out(" lda  $sourceName  | sta  ${target.asmVarname}+$scaledIdx")
@@ -1008,8 +1161,8 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                                 ldy  #>$sourceName
                                 sta  P8ZP_SCRATCH_W1
                                 sty  P8ZP_SCRATCH_W1+1
-                                lda  #<${target.asmVarname}+$scaledIdx
-                                ldy  #>${target.asmVarname}+$scaledIdx
+                                lda  #<(${target.asmVarname}+$scaledIdx)
+                                ldy  #>(${target.asmVarname}+$scaledIdx)
                                 jsr  floats.copy_float
                             """)
                         }
@@ -1044,7 +1197,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                                 adc  #<${target.asmVarname}
                                 bcc  +
                                 iny
-+                                   jsr  floats.copy_float""")
++                               jsr  floats.copy_float""")
                         }
                         else -> throw AssemblyError("weird dt")
                     }
@@ -1078,6 +1231,11 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
         }
     }
 
+    internal fun assignFAC2float(target: AsmAssignTarget) {
+        asmgen.out("  jsr  floats.MOVFA")       // fac2 -> fac1
+        assignFAC1float(target)
+    }
+
     internal fun assignFAC1float(target: AsmAssignTarget) {
         when(target.kind) {
             TargetStorageKind.VARIABLE -> {
@@ -1156,17 +1314,13 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
         when(target.kind) {
             TargetStorageKind.VARIABLE -> {
                 asmgen.out("""
-                    lda  $sourceName
-                    sta  ${target.asmVarname}
-                    lda  $sourceName+1
-                    sta  ${target.asmVarname}+1
-                    lda  $sourceName+2
-                    sta  ${target.asmVarname}+2
-                    lda  $sourceName+3
-                    sta  ${target.asmVarname}+3
-                    lda  $sourceName+4
-                    sta  ${target.asmVarname}+4
-                """)
+                    lda  #<$sourceName
+                    ldy  #>$sourceName
+                    sta  P8ZP_SCRATCH_W1
+                    sty  P8ZP_SCRATCH_W1+1
+                    lda  #<${target.asmVarname}
+                    ldy  #>${target.asmVarname}
+                    jsr  floats.copy_float""")
             }
             TargetStorageKind.ARRAY -> {
                 asmgen.out("""
@@ -1213,7 +1367,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
             }
             TargetStorageKind.ARRAY -> {
                 if (target.constArrayIndexValue!=null) {
-                    val scaledIdx = target.constArrayIndexValue!! * program.memsizer.memorySize(target.datatype)
+                    val scaledIdx = target.constArrayIndexValue!! * program.memsizer.memorySize(target.datatype).toUInt()
                     asmgen.out(" lda  $sourceName  | sta  ${target.asmVarname}+$scaledIdx")
                 }
                 else {
@@ -1266,7 +1420,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
             }
             TargetStorageKind.ARRAY -> {
                 if (wordtarget.constArrayIndexValue!=null) {
-                    val scaledIdx = wordtarget.constArrayIndexValue!! * 2
+                    val scaledIdx = wordtarget.constArrayIndexValue!! * 2u
                     asmgen.out("  lda  $sourceName")
                     asmgen.signExtendAYlsb(DataType.BYTE)
                     asmgen.out("  sta  ${wordtarget.asmVarname}+$scaledIdx |  sty  ${wordtarget.asmVarname}+$scaledIdx+1")
@@ -1287,7 +1441,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                         pha
                         ora  #$7f
                         bmi  +
-                        ldx  #0
+                        lda  #0
 +                       tax
                         pla""")
                     RegisterOrPair.AY -> asmgen.out("""
@@ -1295,7 +1449,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                         pha
                         ora  #$7f
                         bmi  +
-                        ldy  #0
+                        lda  #0
 +                       tay
                         pla""")
                     RegisterOrPair.XY -> asmgen.out("""
@@ -1303,9 +1457,19 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                         tax 
                         ora  #$7f
                         bmi  +
-                        ldy  #0
+                        lda  #0
 +                       tay""")
-                    else -> throw AssemblyError("only reg pairs are words")
+                    in Cx16VirtualRegisters -> {
+                        val regname = wordtarget.register.name.lowercase()
+                        asmgen.out("""
+                            lda  $sourceName
+                            sta  cx16.$regname
+                            ora  #$7f
+                            bmi  +
+                            lda  #0
++                           sta  cx16.$regname+1""")
+                    }
+                    else -> throw AssemblyError("only reg pairs allowed as word target ${wordtarget.register}")
                 }
             }
             TargetStorageKind.STACK -> {
@@ -1334,7 +1498,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
             }
             TargetStorageKind.ARRAY -> {
                 if (wordtarget.constArrayIndexValue!=null) {
-                    val scaledIdx = wordtarget.constArrayIndexValue!! * 2
+                    val scaledIdx = wordtarget.constArrayIndexValue!! * 2u
                     asmgen.out("  lda  $sourceName  | sta  ${wordtarget.asmVarname}+$scaledIdx")
                     if(asmgen.isTargetCpu(CpuType.CPU65c02))
                         asmgen.out("  stz  ${wordtarget.asmVarname}+$scaledIdx+1")
@@ -1356,7 +1520,14 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                     RegisterOrPair.AX -> asmgen.out("  ldx  #0 |  lda  $sourceName")
                     RegisterOrPair.AY -> asmgen.out("  ldy  #0 |  lda  $sourceName")
                     RegisterOrPair.XY -> asmgen.out("  ldy  #0 |  ldx  $sourceName")
-                    else -> throw AssemblyError("only reg pairs are words")
+                    in Cx16VirtualRegisters -> {
+                        val regname = wordtarget.register.name.lowercase()
+                        if(asmgen.isTargetCpu(CpuType.CPU65c02))
+                            asmgen.out("  lda  $sourceName |  sta  cx16.$regname |  stz  cx16.$regname+1")
+                        else
+                            asmgen.out("  lda  $sourceName |  sta  cx16.$regname |  lda  #0 |  sta  cx16.$regname+1")
+                    }
+                    else -> throw AssemblyError("only reg pairs allowed as word target")
                 }
             }
             TargetStorageKind.STACK -> {
@@ -1494,7 +1665,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
             }
             TargetStorageKind.ARRAY -> {
                 if (target.constArrayIndexValue!=null) {
-                    val idx = target.constArrayIndexValue!! * 2
+                    val idx = target.constArrayIndexValue!! * 2u
                     when (regs) {
                         RegisterOrPair.AX -> asmgen.out("  sta  ${target.asmVarname}+$idx |  stx  ${target.asmVarname}+$idx+1")
                         RegisterOrPair.AY -> asmgen.out("  sta  ${target.asmVarname}+$idx |  sty  ${target.asmVarname}+$idx+1")
@@ -1624,7 +1795,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                     asmgen.out("  stz  ${target.asmVarname} |  stz  ${target.asmVarname}+1")
                 }
                 TargetStorageKind.MEMORY -> {
-                    throw AssemblyError("no asm gen for assign word $word to memory ${target.memory}")
+                    throw AssemblyError("memory is bytes not words")
                 }
                 TargetStorageKind.ARRAY -> {
                     asmgen.loadScaledArrayIndexIntoRegister(target.array!!, DataType.UWORD, CpuRegister.Y)
@@ -1715,15 +1886,15 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
         }
     }
 
-    private fun assignConstantByte(target: AsmAssignTarget, byte: Short) {
-        if(byte==0.toShort() && asmgen.isTargetCpu(CpuType.CPU65c02)) {
+    private fun assignConstantByte(target: AsmAssignTarget, byte: Int) {
+        if(byte==0 && asmgen.isTargetCpu(CpuType.CPU65c02)) {
             // optimize setting zero value for this cpu
             when(target.kind) {
                 TargetStorageKind.VARIABLE -> {
                     asmgen.out("  stz  ${target.asmVarname} ")
                 }
                 TargetStorageKind.MEMORY -> {
-                    asmgen.out("  lda  #${byte.toHex()}")
+                    asmgen.out("  lda  #0")
                     storeRegisterAInMemoryAddress(target.memory!!)
                 }
                 TargetStorageKind.ARRAY -> {
@@ -1869,7 +2040,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                 }
                 TargetStorageKind.MEMORY -> throw AssemblyError("can't assign float to memory byte")
                 TargetStorageKind.REGISTER -> {
-                    val floatConst = asmgen.getFloatAsmConst(float)
+                    val floatConst = allocator.getFloatAsmConst(float)
                     when(target.register!!) {
                         RegisterOrPair.FAC1 -> asmgen.out("  lda  #<$floatConst  | ldy  #>$floatConst |  jsr  floats.MOVFM")
                         RegisterOrPair.FAC2 -> asmgen.out("  lda  #<$floatConst  | ldy  #>$floatConst |  jsr  floats.CONUPK")
@@ -1877,27 +2048,23 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                     }
                 }
                 TargetStorageKind.STACK -> {
-                    val floatConst = asmgen.getFloatAsmConst(float)
+                    val floatConst = allocator.getFloatAsmConst(float)
                     asmgen.out(" lda  #<$floatConst |  ldy  #>$floatConst |  jsr  floats.push_float")
                 }
             }
         } else {
             // non-zero value
-            val constFloat = asmgen.getFloatAsmConst(float)
+            val constFloat = allocator.getFloatAsmConst(float)
             when(target.kind) {
                 TargetStorageKind.VARIABLE -> {
                     asmgen.out("""
-                            lda  $constFloat
-                            sta  ${target.asmVarname}
-                            lda  $constFloat+1
-                            sta  ${target.asmVarname}+1
-                            lda  $constFloat+2
-                            sta  ${target.asmVarname}+2
-                            lda  $constFloat+3
-                            sta  ${target.asmVarname}+3
-                            lda  $constFloat+4
-                            sta  ${target.asmVarname}+4
-                        """)
+                        lda  #<$constFloat
+                        ldy  #>$constFloat
+                        sta  P8ZP_SCRATCH_W1
+                        sty  P8ZP_SCRATCH_W1+1
+                        lda  #<${target.asmVarname}
+                        ldy  #>${target.asmVarname}
+                        jsr  floats.copy_float""")
                 }
                 TargetStorageKind.ARRAY -> {
                     val arrayVarName = target.asmVarname
@@ -1905,17 +2072,13 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                     if (constIndex!=null) {
                         val indexValue = constIndex * program.memsizer.memorySize(DataType.FLOAT)
                         asmgen.out("""
-                            lda  $constFloat
-                            sta  $arrayVarName+$indexValue
-                            lda  $constFloat+1
-                            sta  $arrayVarName+$indexValue+1
-                            lda  $constFloat+2
-                            sta  $arrayVarName+$indexValue+2
-                            lda  $constFloat+3
-                            sta  $arrayVarName+$indexValue+3
-                            lda  $constFloat+4
-                            sta  $arrayVarName+$indexValue+4
-                        """)
+                            lda  #<$constFloat
+                            ldy  #>$constFloat
+                            sta  P8ZP_SCRATCH_W1
+                            sty  P8ZP_SCRATCH_W1+1
+                            lda  #<($arrayVarName+$indexValue)
+                            ldy  #>($arrayVarName+$indexValue)
+                            jsr  floats.copy_float""")
                     } else {
                         val asmvarname = asmgen.asmVariableName(target.array.indexer.indexExpr as IdentifierReference)
                         asmgen.out("""
@@ -1934,7 +2097,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                 }
                 TargetStorageKind.MEMORY -> throw AssemblyError("can't assign float to memory byte")
                 TargetStorageKind.REGISTER -> {
-                    val floatConst = asmgen.getFloatAsmConst(float)
+                    val floatConst = allocator.getFloatAsmConst(float)
                     when(target.register!!) {
                         RegisterOrPair.FAC1 -> asmgen.out("  lda  #<$floatConst  | ldy  #>$floatConst |  jsr  floats.MOVFM")
                         RegisterOrPair.FAC2 -> asmgen.out("  lda  #<$floatConst  | ldy  #>$floatConst |  jsr  floats.CONUPK")
@@ -1942,14 +2105,14 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                     }
                 }
                 TargetStorageKind.STACK -> {
-                    val floatConst = asmgen.getFloatAsmConst(float)
+                    val floatConst = allocator.getFloatAsmConst(float)
                     asmgen.out(" lda  #<$floatConst |  ldy  #>$floatConst |  jsr  floats.push_float")
                 }
             }
         }
     }
 
-    private fun assignMemoryByte(target: AsmAssignTarget, address: Int?, identifier: IdentifierReference?) {
+    private fun assignMemoryByte(target: AsmAssignTarget, address: UInt?, identifier: IdentifierReference?) {
         if (address != null) {
             when(target.kind) {
                 TargetStorageKind.VARIABLE -> {
@@ -2033,7 +2196,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
         }
     }
 
-    private fun assignMemoryByteIntoWord(wordtarget: AsmAssignTarget, address: Int?, identifier: IdentifierReference?) {
+    private fun assignMemoryByteIntoWord(wordtarget: AsmAssignTarget, address: UInt?, identifier: IdentifierReference?) {
         if (address != null) {
             when(wordtarget.kind) {
                 TargetStorageKind.VARIABLE -> {
@@ -2098,58 +2261,20 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
 
     private fun storeRegisterAInMemoryAddress(memoryAddress: DirectMemoryWrite) {
         val addressExpr = memoryAddress.addressExpression
-        val addressLv = addressExpr as? NumericLiteralValue
+        val addressLv = addressExpr as? NumericLiteral
 
         fun storeViaExprEval() {
             when(addressExpr) {
-                is NumericLiteralValue, is IdentifierReference -> {
+                is NumericLiteral, is IdentifierReference -> {
                     assignExpressionToVariable(addressExpr, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
-                    if (asmgen.isTargetCpu(CpuType.CPU65c02))
-                        asmgen.out("  sta  (P8ZP_SCRATCH_W2)")
-                    else
-                        asmgen.out("  ldy  #0 |  sta  (P8ZP_SCRATCH_W2),y")
+                    asmgen.storeAIntoZpPointerVar("P8ZP_SCRATCH_W2")
                 }
                 else -> {
                     // same as above but we need to save the A register
                     asmgen.out("  pha")
                     assignExpressionToVariable(addressExpr, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
                     asmgen.out("  pla")
-                    if (asmgen.isTargetCpu(CpuType.CPU65c02))
-                        asmgen.out("  sta  (P8ZP_SCRATCH_W2)")
-                    else
-                        asmgen.out("  ldy  #0 |  sta  (P8ZP_SCRATCH_W2),y")
-                }
-            }
-        }
-
-        fun storeAIntoPointerVar(pointervar: IdentifierReference) {
-            val sourceName = asmgen.asmVariableName(pointervar)
-            val vardecl = pointervar.targetVarDecl(program)!!
-            val scopedName = vardecl.makeScopedName(vardecl.name)
-            if (asmgen.isTargetCpu(CpuType.CPU65c02)) {
-                if (asmgen.isZpVar(scopedName)) {
-                    // pointervar is already in the zero page, no need to copy
-                    asmgen.out("  sta  ($sourceName)")
-                } else {
-                    asmgen.out("""
-                    ldy  $sourceName
-                    sty  P8ZP_SCRATCH_W2
-                    ldy  $sourceName+1
-                    sty  P8ZP_SCRATCH_W2+1
-                    sta  (P8ZP_SCRATCH_W2)""")
-                }
-            } else {
-                if (asmgen.isZpVar(scopedName)) {
-                    // pointervar is already in the zero page, no need to copy
-                    asmgen.out(" ldy  #0 |  sta  ($sourceName),y")
-                } else {
-                    asmgen.out("""
-                    ldy  $sourceName
-                    sty  P8ZP_SCRATCH_W2
-                    ldy  $sourceName+1
-                    sty  P8ZP_SCRATCH_W2+1
-                    ldy  #0
-                    sta  (P8ZP_SCRATCH_W2),y""")
+                    asmgen.storeAIntoZpPointerVar("P8ZP_SCRATCH_W2")
                 }
             }
         }
@@ -2159,7 +2284,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                 asmgen.out("  sta  ${addressLv.number.toHex()}")
             }
             addressExpr is IdentifierReference -> {
-                storeAIntoPointerVar(addressExpr)
+                asmgen.storeAIntoPointerVar(addressExpr)
             }
             addressExpr is BinaryExpression -> {
                 if(!asmgen.tryOptimizedPointerAccessWithA(addressExpr, true))

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

@@ -1,19 +1,18 @@
-package prog8.compiler.target.cpu6502.codegen.assignment
+package prog8.codegen.cpu6502.assignment
 
 import prog8.ast.Program
-import prog8.ast.base.*
+import prog8.ast.base.FatalAstException
 import prog8.ast.expressions.*
 import prog8.ast.statements.Subroutine
-import prog8.ast.toHex
-import prog8.compiler.target.AssemblyError
-import prog8.compiler.target.cpu6502.codegen.AsmGen
-import prog8.compiler.target.cpu6502.codegen.ExpressionsAsmGen
-import prog8.compilerinterface.CpuType
+import prog8.code.core.*
+import prog8.codegen.cpu6502.AsmGen
+import prog8.codegen.cpu6502.VariableAllocator
+
 
 internal class AugmentableAssignmentAsmGen(private val program: Program,
                                            private val assignmentAsmGen: AssignmentAsmGen,
-                                           private val exprAsmGen: ExpressionsAsmGen,
-                                           private val asmgen: AsmGen
+                                           private val asmgen: AsmGen,
+                                           private val allocator: VariableAllocator
 ) {
     fun translate(assign: AsmAssignment) {
         require(assign.isAugmentable)
@@ -22,15 +21,14 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
         when (val value = assign.source.expression!!) {
             is PrefixExpression -> {
                 // A = -A , A = +A, A = ~A, A = not A
+                val target = assignmentAsmGen.virtualRegsToVariables(assign.target)
                 val itype = value.inferType(program)
-                if(!itype.isKnown)
-                    throw AssemblyError("unknown dt")
-                val type = itype.getOr(DataType.UNDEFINED)
+                val type = itype.getOrElse { throw AssemblyError("unknown dt") }
                 when (value.operator) {
                     "+" -> {}
-                    "-" -> inplaceNegate(assign.target, type)
-                    "~" -> inplaceInvert(assign.target, type)
-                    "not" -> inplaceBooleanNot(assign.target, type)
+                    "-" -> inplaceNegate(target, type)
+                    "~" -> inplaceInvert(target, type)
+                    "not" -> inplaceBooleanNot(target, type)
                     else -> throw AssemblyError("invalid prefix operator")
                 }
             }
@@ -47,7 +45,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
             return inplaceModification(target, binExpr.operator, binExpr.right)
         }
 
-        if (binExpr.operator in associativeOperators) {
+        if (binExpr.operator in AssociativeOperators) {
             if (binExpr.right isSameAs astTarget) {
                 // A = 5 <operator> A
                 return inplaceModification(target, binExpr.operator, binExpr.left)
@@ -102,11 +100,67 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
             }
         }
 
-        throw FatalAstException("assignment should be augmentable $binExpr")
+        val leftBinExpr = binExpr.left as? BinaryExpression
+        val rightBinExpr = binExpr.right as? BinaryExpression
+        if(leftBinExpr!=null && rightBinExpr==null) {
+            if(leftBinExpr.left isSameAs astTarget) {
+                // X = (X <oper> Right) <oper> Something
+                inplaceModification(target, leftBinExpr.operator, leftBinExpr.right)
+                inplaceModification(target, binExpr.operator, binExpr.right)
+                return
+            }
+            if(leftBinExpr.right isSameAs astTarget) {
+                // X = (Left <oper> X) <oper> Something
+                if(leftBinExpr.operator in AssociativeOperators) {
+                    inplaceModification(target, leftBinExpr.operator, leftBinExpr.left)
+                    inplaceModification(target, binExpr.operator, binExpr.right)
+                    return
+                } else {
+                    throw AssemblyError("operands in wrong order for non-associative operator")
+                }
+            }
+        }
+        if(leftBinExpr==null && rightBinExpr!=null) {
+            if(rightBinExpr.left isSameAs astTarget) {
+                // X = Something <oper> (X <oper> Right)
+                if(binExpr.operator in AssociativeOperators) {
+                    inplaceModification(target, rightBinExpr.operator, rightBinExpr.right)
+                    inplaceModification(target, binExpr.operator, binExpr.left)
+                    return
+                } else {
+                    throw AssemblyError("operands in wrong order for non-associative operator")
+                }
+            }
+            if(rightBinExpr.right isSameAs astTarget) {
+                // X = Something <oper> (Left <oper> X)
+                if(binExpr.operator in AssociativeOperators && rightBinExpr.operator in AssociativeOperators) {
+                    inplaceModification(target, rightBinExpr.operator, rightBinExpr.left)
+                    inplaceModification(target, binExpr.operator, binExpr.left)
+                    return
+                } else {
+                    throw AssemblyError("operands in wrong order for non-associative operator")
+                }
+            }
+        }
+
+        throw FatalAstException("assignment should follow augmentable rules $binExpr")
     }
 
-    private fun inplaceModification(target: AsmAssignTarget, operator: String, value: Expression) {
-        val valueLv = (value as? NumericLiteralValue)?.number
+    private fun inplaceModification(target: AsmAssignTarget, operator: String, origValue: Expression) {
+
+        // the asm-gen code can deal with situations where you want to assign a byte into a word.
+        // it will create the most optimized code to do this (so it type-extends for us).
+        // But we can't deal with writing a word into a byte - explicit typeconversion is required
+        val value = if(program.memsizer.memorySize(origValue.inferType(program).getOrElse { throw AssemblyError("unknown dt") }) > program.memsizer.memorySize(target.datatype)) {
+            val typecast = TypecastExpression(origValue, target.datatype, true, origValue.position)
+            typecast.linkParents(origValue.parent)
+            typecast
+        }
+        else {
+            origValue
+        }
+
+        val valueLv = (value as? NumericLiteral)?.number
         val ident = value as? IdentifierReference
         val memread = value as? DirectMemoryRead
 
@@ -119,7 +173,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                             ident != null -> inplaceModification_byte_variable_to_variable(target.asmVarname, target.datatype, operator, ident)
                             memread != null -> inplaceModification_byte_memread_to_variable(target.asmVarname, target.datatype, operator, memread)
                             value is TypecastExpression -> {
-                                if (tryRemoveRedundantCast(value, target, operator)) return
+                                if (tryInplaceModifyWithRemovedRedundantCast(value, target, operator)) return
                                 inplaceModification_byte_value_to_variable(target.asmVarname, target.datatype, operator, value)
                             }
                             else -> inplaceModification_byte_value_to_variable(target.asmVarname, target.datatype, operator, value)
@@ -131,7 +185,8 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                             ident != null -> inplaceModification_word_variable_to_variable(target.asmVarname, target.datatype, operator, ident)
                             memread != null -> inplaceModification_word_memread_to_variable(target.asmVarname, target.datatype, operator, memread)
                             value is TypecastExpression -> {
-                                if (tryRemoveRedundantCast(value, target, operator)) return
+                                if (tryInplaceModifyWithRemovedRedundantCast(value, target, operator))
+                                    return
                                 inplaceModification_word_value_to_variable(target.asmVarname, target.datatype, operator, value)
                             }
                             else -> inplaceModification_word_value_to_variable(target.asmVarname, target.datatype, operator, value)
@@ -142,7 +197,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                             valueLv != null -> inplaceModification_float_litval_to_variable(target.asmVarname, operator, valueLv.toDouble(), target.scope!!)
                             ident != null -> inplaceModification_float_variable_to_variable(target.asmVarname, operator, ident, target.scope!!)
                             value is TypecastExpression -> {
-                                if (tryRemoveRedundantCast(value, target, operator)) return
+                                if (tryInplaceModifyWithRemovedRedundantCast(value, target, operator)) return
                                 inplaceModification_float_value_to_variable(target.asmVarname, operator, value, target.scope!!)
                             }
                             else -> inplaceModification_float_value_to_variable(target.asmVarname, operator, value, target.scope!!)
@@ -154,15 +209,15 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
             TargetStorageKind.MEMORY -> {
                 val memory = target.memory!!
                 when (memory.addressExpression) {
-                    is NumericLiteralValue -> {
-                        val addr = (memory.addressExpression as NumericLiteralValue).number.toInt()
+                    is NumericLiteral -> {
+                        val addr = (memory.addressExpression as NumericLiteral).number.toInt()
                         // re-use code to assign a variable, instead this time, use a direct memory address
                         when {
                             valueLv != null -> inplaceModification_byte_litval_to_variable(addr.toHex(), DataType.UBYTE, operator, valueLv.toInt())
                             ident != null -> inplaceModification_byte_variable_to_variable(addr.toHex(), DataType.UBYTE, operator, ident)
                             memread != null -> inplaceModification_byte_memread_to_variable(addr.toHex(), DataType.UBYTE, operator, value)
                             value is TypecastExpression -> {
-                                if (tryRemoveRedundantCast(value, target, operator)) return
+                                if (tryInplaceModifyWithRemovedRedundantCast(value, target, operator)) return
                                 inplaceModification_byte_value_to_variable(addr.toHex(), DataType.UBYTE, operator, value)
                             }
                             else -> inplaceModification_byte_value_to_variable(addr.toHex(), DataType.UBYTE, operator, value)
@@ -174,33 +229,33 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                             valueLv != null -> inplaceModification_byte_litval_to_pointer(pointer, operator, valueLv.toInt())
                             ident != null -> inplaceModification_byte_variable_to_pointer(pointer, operator, ident)
                             value is TypecastExpression -> {
-                                if (tryRemoveRedundantCast(value, target, operator)) return
+                                if (tryInplaceModifyWithRemovedRedundantCast(value, target, operator)) return
                                 inplaceModification_byte_value_to_pointer(pointer, operator, value)
                             }
                             else -> inplaceModification_byte_value_to_pointer(pointer, operator, value)
                         }
                     }
                     else -> {
-                        // TODO OTHER EVALUATION HERE, don't use the estack
+                        // TODO use some other evaluation here; don't use the estack to transfer the address to read/write from
                         asmgen.assignExpressionTo(memory.addressExpression, AsmAssignTarget(TargetStorageKind.STACK, program, asmgen, DataType.UWORD, memory.definingSubroutine))
-                        asmgen.out("  jsr  prog8_lib.read_byte_from_address_on_stack |  sta  P8ZP_SCRATCH_B1")      // TODO don't use estack to transfer the address to read from
+                        asmgen.out("  jsr  prog8_lib.read_byte_from_address_on_stack |  sta  P8ZP_SCRATCH_B1")
                         when {
                             valueLv != null -> inplaceModification_byte_litval_to_variable("P8ZP_SCRATCH_B1", DataType.UBYTE, operator, valueLv.toInt())
                             ident != null -> inplaceModification_byte_variable_to_variable("P8ZP_SCRATCH_B1", DataType.UBYTE, operator, ident)
                             memread != null -> inplaceModification_byte_memread_to_variable("P8ZP_SCRATCH_B1", DataType.UBYTE, operator, memread)
                             value is TypecastExpression -> {
-                                if (tryRemoveRedundantCast(value, target, operator)) return
+                                if (tryInplaceModifyWithRemovedRedundantCast(value, target, operator)) return
                                 inplaceModification_byte_value_to_variable("P8ZP_SCRATCH_B1", DataType.UBYTE, operator, value)
                             }
                             else -> inplaceModification_byte_value_to_variable("P8ZP_SCRATCH_B1", DataType.UBYTE, operator, value)
                         }
-                        asmgen.out("  lda  P8ZP_SCRATCH_B1 |  jsr  prog8_lib.write_byte_to_address_on_stack | inx")  // TODO don't use estack to transfer the address to read from
+                        asmgen.out("  lda  P8ZP_SCRATCH_B1 |  jsr  prog8_lib.write_byte_to_address_on_stack | inx")
                     }
                 }
             }
             TargetStorageKind.ARRAY -> {
                 with(target.array!!.indexer) {
-                    val indexNum = indexExpr as? NumericLiteralValue
+                    val indexNum = indexExpr as? NumericLiteral
                     val indexVar = indexExpr as? IdentifierReference
                     when {
                         indexNum!=null -> {
@@ -212,7 +267,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                                         ident != null -> inplaceModification_byte_variable_to_variable(targetVarName, target.datatype, operator, ident)
                                         memread != null -> inplaceModification_byte_memread_to_variable(targetVarName, target.datatype, operator, memread)
                                         value is TypecastExpression -> {
-                                            if (tryRemoveRedundantCast(value, target, operator)) return
+                                            if (tryInplaceModifyWithRemovedRedundantCast(value, target, operator)) return
                                             inplaceModification_byte_value_to_variable(targetVarName, target.datatype, operator, value)
                                         }
                                         else -> inplaceModification_byte_value_to_variable(targetVarName, target.datatype, operator, value)
@@ -224,7 +279,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                                         ident != null -> inplaceModification_word_variable_to_variable(targetVarName, target.datatype, operator, ident)
                                         memread != null -> inplaceModification_word_memread_to_variable(targetVarName, target.datatype, operator, memread)
                                         value is TypecastExpression -> {
-                                            if (tryRemoveRedundantCast(value, target, operator)) return
+                                            if (tryInplaceModifyWithRemovedRedundantCast(value, target, operator)) return
                                             inplaceModification_word_value_to_variable(targetVarName, target.datatype, operator, value)
                                         }
                                         else -> inplaceModification_word_value_to_variable(targetVarName, target.datatype, operator, value)
@@ -235,7 +290,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                                         valueLv != null -> inplaceModification_float_litval_to_variable(targetVarName, operator, valueLv.toDouble(), target.scope!!)
                                         ident != null -> inplaceModification_float_variable_to_variable(targetVarName, operator, ident, target.scope!!)
                                         value is TypecastExpression -> {
-                                            if (tryRemoveRedundantCast(value, target, operator)) return
+                                            if (tryInplaceModifyWithRemovedRedundantCast(value, target, operator)) return
                                             inplaceModification_float_value_to_variable(targetVarName, operator, value, target.scope!!)
                                         }
                                         else -> inplaceModification_float_value_to_variable(targetVarName, operator, value, target.scope!!)
@@ -289,17 +344,15 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     }
                 }
             }
-            TargetStorageKind.REGISTER -> throw AssemblyError("missing codegen for reg in-place modification")
-            TargetStorageKind.STACK -> throw AssemblyError("missing codegen for stack in-place modification")
+            TargetStorageKind.REGISTER -> throw AssemblyError("no asm gen for reg in-place modification")
+            TargetStorageKind.STACK -> throw AssemblyError("no asm gen for stack in-place modification")
         }
     }
 
-    private fun tryRemoveRedundantCast(value: TypecastExpression, target: AsmAssignTarget, operator: String): Boolean {
+    private fun tryInplaceModifyWithRemovedRedundantCast(value: TypecastExpression, target: AsmAssignTarget, operator: String): Boolean {
         if (target.datatype == value.type) {
             val childIDt = value.expression.inferType(program)
-            if(!childIDt.isKnown)
-                throw AssemblyError("unknown dt")
-            val childDt = childIDt.getOr(DataType.UNDEFINED)
+            val childDt = childIDt.getOrElse { throw AssemblyError("unknown dt") }
             if (value.type!=DataType.FLOAT && (value.type.equalsSize(childDt) || value.type.largerThan(childDt))) {
                 // this typecast is redundant here; the rest of the code knows how to deal with the uncasted value.
                 // (works for integer types, not for float.)
@@ -312,13 +365,14 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
 
     private fun inplaceModification_byte_value_to_pointer(pointervar: IdentifierReference, operator: String, value: Expression) {
         asmgen.assignExpressionToVariable(value, "P8ZP_SCRATCH_B1", DataType.UBYTE, null)
+        val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
         when (operator) {
             // note: ** (power) operator requires floats.
             "+" -> asmgen.out("  clc |  adc  P8ZP_SCRATCH_B1")
             "-" -> asmgen.out("  sec |  sbc  P8ZP_SCRATCH_B1")
-            "*" -> asmgen.out("  ldy  P8ZP_SCRATCH_B1 |  jsr  math.multiply_bytes |  ldy  #0")
-            "/" -> asmgen.out("  ldy  P8ZP_SCRATCH_B1 |  jsr  math.divmod_ub_asm |  tya |  ldy  #0")
-            "%" -> asmgen.out("  ldy  P8ZP_SCRATCH_B1 |  jsr  math.divmod_ub_asm |  ldy  #0")
+            "*" -> asmgen.out("  ldy  P8ZP_SCRATCH_B1 |  jsr  math.multiply_bytes")
+            "/" -> asmgen.out("  ldy  P8ZP_SCRATCH_B1 |  jsr  math.divmod_ub_asm |  tya")
+            "%" -> asmgen.out("  ldy  P8ZP_SCRATCH_B1 |  jsr  math.divmod_ub_asm")
             "<<" -> {
                 asmgen.out("""
                     ldy  P8ZP_SCRATCH_B1
@@ -342,8 +396,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
             "^", "xor" -> asmgen.out(" eor  P8ZP_SCRATCH_B1")
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
-        val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
-        asmgen.out("  sta  ($sourceName),y")
+        asmgen.storeAIntoZpPointerVar(sourceName)
     }
 
     private fun inplaceModification_byte_variable_to_pointer(pointervar: IdentifierReference, operator: String, value: IdentifierReference) {
@@ -354,9 +407,9 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
             // note: ** (power) operator requires floats.
             "+" -> asmgen.out("  clc |  adc  $otherName")
             "-" -> asmgen.out("  sec |  sbc  $otherName")
-            "*" -> asmgen.out("  ldy  $otherName |  jsr  math.multiply_bytes |  ldy  #0")
-            "/" -> asmgen.out("  ldy  $otherName |  jsr  math.divmod_ub_asm |  tya |  ldy  #0")
-            "%" -> asmgen.out("  ldy  $otherName |  jsr  math.divmod_ub_asm |  ldy  #0")
+            "*" -> asmgen.out("  ldy  $otherName |  jsr  math.multiply_bytes")
+            "/" -> asmgen.out("  ldy  $otherName |  jsr  math.divmod_ub_asm |  tya")
+            "%" -> asmgen.out("  ldy  $otherName |  jsr  math.divmod_ub_asm")
             "<<" -> {
                 asmgen.out("""
                         ldy  $otherName
@@ -380,7 +433,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
             "^", "xor" -> asmgen.out(" eor  $otherName")
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
-        asmgen.out("  sta  ($sourceName),y")
+        asmgen.storeAIntoZpPointerVar(sourceName)
     }
 
     private fun inplaceModification_byte_litval_to_pointer(pointervar: IdentifierReference, operator: String, value: Int) {
@@ -389,63 +442,63 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
             "+" -> {
                 val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
                 asmgen.out("  clc |  adc  #$value")
-                asmgen.out("  sta  ($sourceName),y")
+                asmgen.storeAIntoZpPointerVar(sourceName)
             }
             "-" -> {
                 val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
                 asmgen.out("  sec |  sbc  #$value")
-                asmgen.out("  sta  ($sourceName),y")
+                asmgen.storeAIntoZpPointerVar(sourceName)
             }
             "*" -> {
                 val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
                 if(value in asmgen.optimizedByteMultiplications)
                     asmgen.out("  jsr  math.mul_byte_${value}")
                 else
-                    asmgen.out("  ldy  #$value |  jsr  math.multiply_bytes |  ldy  #0")
-                asmgen.out("  sta  ($sourceName),y")
+                    asmgen.out("  ldy  #$value |  jsr  math.multiply_bytes")
+                asmgen.storeAIntoZpPointerVar(sourceName)
             }
             "/" -> {
                 val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
                 if(value==0)
                     throw AssemblyError("division by zero")
-                asmgen.out("  ldy  #$value |  jsr  math.divmod_ub_asm |  tya |  ldy  #0")
-                asmgen.out("  sta  ($sourceName),y")
+                asmgen.out("  ldy  #$value |  jsr  math.divmod_ub_asm |  tya")
+                asmgen.storeAIntoZpPointerVar(sourceName)
             }
             "%" -> {
                 val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
                 if(value==0)
                     throw AssemblyError("division by zero")
-                asmgen.out("  ldy  #$value |  jsr  math.divmod_ub_asm |  ldy  #0")
-                asmgen.out("  sta  ($sourceName),y")
+                asmgen.out("  ldy  #$value |  jsr  math.divmod_ub_asm")
+                asmgen.storeAIntoZpPointerVar(sourceName)
             }
             "<<" -> {
                 if (value > 0) {
                     val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
-                    repeat(value) { asmgen.out(" asl  a") }
-                    asmgen.out("  sta  ($sourceName),y")
+                    repeat(value) { asmgen.out("  asl  a") }
+                    asmgen.storeAIntoZpPointerVar(sourceName)
                 }
             }
             ">>" -> {
                 if (value > 0) {
                     val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
-                    repeat(value) { asmgen.out(" lsr  a") }
-                    asmgen.out("  sta  ($sourceName),y")
+                    repeat(value) { asmgen.out("  lsr  a") }
+                    asmgen.storeAIntoZpPointerVar(sourceName)
                 }
             }
             "&", "and" -> {
                 val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
                 asmgen.out("  and  #$value")
-                asmgen.out("  sta  ($sourceName),y")
+                asmgen.storeAIntoZpPointerVar(sourceName)
             }
             "|", "or" -> {
                 val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
                 asmgen.out("  ora  #$value")
-                asmgen.out("  sta  ($sourceName),y")
+                asmgen.storeAIntoZpPointerVar(sourceName)
             }
             "^", "xor" -> {
                 val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
                 asmgen.out("  eor  #$value")
-                asmgen.out("  sta  ($sourceName),y")
+                asmgen.storeAIntoZpPointerVar(sourceName)
             }
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
@@ -522,6 +575,26 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                 asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
                 asmgen.out("  eor  $name |  sta  $name")
             }
+            "==" -> {
+                asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
+                asmgen.out("""
+                    cmp  $name
+                    beq  +
+                    lda  #0
+                    beq  ++
++                   lda  #1
++                   sta  $name""")
+            }
+            "!=" -> {
+                asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
+                asmgen.out("""
+                    cmp  $name
+                    beq  +
+                    lda  #1
+                    bne  ++
++                   lda  #0
++                   sta  $name""")
+            }
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
     }
@@ -579,6 +652,26 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
             "&", "and" -> asmgen.out(" lda  $name |  and  $otherName |  sta  $name")
             "|", "or" -> asmgen.out(" lda  $name |  ora  $otherName |  sta  $name")
             "^", "xor" -> asmgen.out(" lda  $name |  eor  $otherName |  sta  $name")
+            "==" -> {
+                asmgen.out("""
+                    lda  $otherName
+                    cmp  $name
+                    beq  +
+                    lda  #0
+                    bne  ++
++                   lda  #1
++                   sta  $name""")
+            }
+            "!=" -> {
+                asmgen.out("""
+                    lda  $otherName
+                    cmp  $name
+                    beq  +
+                    lda  #1
+                    bne  ++
++                   lda  #0
++                   sta  $name""")
+            }
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
     }
@@ -650,6 +743,26 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
             "&", "and" -> asmgen.out(" lda  $name |  and  #$value |  sta  $name")
             "|", "or" -> asmgen.out(" lda  $name |  ora  #$value |  sta  $name")
             "^", "xor" -> asmgen.out(" lda  $name |  eor  #$value |  sta  $name")
+            "==" -> {
+                asmgen.out("""
+                    lda  $name
+                    cmp  #$value
+                    beq  +
+                    lda  #0
+                    beq  ++
++                   lda  #1
++                   sta  $name""")
+            }
+            "!=" -> {
+                asmgen.out("""
+                    lda  $name
+                    cmp  #$value
+                    beq  +
+                    lda  #1
+                    bne  ++
++                   lda  #0
++                   sta  $name""")
+            }
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
     }
@@ -657,14 +770,14 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
     private fun inplaceModification_byte_memread_to_variable(name: String, dt: DataType, operator: String, memread: DirectMemoryRead) {
         when (operator) {
             "+" -> {
-                exprAsmGen.translateDirectMemReadExpression(memread, false)
+                asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("""
                     clc
                     adc  $name
                     sta  $name""")
             }
             "-" -> {
-                exprAsmGen.translateDirectMemReadExpression(memread, false)
+                asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("""
                     sta  P8ZP_SCRATCH_B1
                     lda  $name
@@ -673,15 +786,15 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     sta  $name""")
             }
             "|", "or" -> {
-                exprAsmGen.translateDirectMemReadExpression(memread, false)
+                asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("  ora  $name  |  sta  $name")
             }
             "&", "and" -> {
-                exprAsmGen.translateDirectMemReadExpression(memread, false)
+                asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("  and  $name  |  sta  $name")
             }
             "^", "xor" -> {
-                exprAsmGen.translateDirectMemReadExpression(memread, false)
+                asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("  eor  $name  |  sta  $name")
             }
             // TODO: tuned code for more operators
@@ -694,7 +807,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
     private fun inplaceModification_word_memread_to_variable(name: String, dt: DataType, operator: String, memread: DirectMemoryRead) {
         when (operator) {
             "+" -> {
-                exprAsmGen.translateDirectMemReadExpression(memread, false)
+                asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("""
                     clc
                     adc  $name
@@ -704,7 +817,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
 +""")
             }
             "-" -> {
-                exprAsmGen.translateDirectMemReadExpression(memread, false)
+                asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("""
                     sta  P8ZP_SCRATCH_B1
                     lda  $name
@@ -716,11 +829,11 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
 +""")
             }
             "|", "or" -> {
-                exprAsmGen.translateDirectMemReadExpression(memread, false)
+                asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("  ora  $name  |  sta  $name")
             }
             "&", "and" -> {
-                exprAsmGen.translateDirectMemReadExpression(memread, false)
+                asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("  and  $name  |  sta  $name")
                 if(dt in WordDatatypes) {
                     if(asmgen.isTargetCpu(CpuType.CPU65c02))
@@ -730,7 +843,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                 }
             }
             "^", "xor" -> {
-                exprAsmGen.translateDirectMemReadExpression(memread, false)
+                asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("  eor  $name  |  sta  $name")
             }
             // TODO: tuned code for more operators
@@ -954,6 +1067,18 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                         else
                             asmgen.out("  lda  #0 |  sta  $name |  sta  $name+1")
                     }
+                    value == 0x00ff -> {
+                        if(asmgen.isTargetCpu(CpuType.CPU65c02))
+                            asmgen.out("  stz  $name+1")
+                        else
+                            asmgen.out("  lda  #0 |  sta  $name+1")
+                    }
+                    value == 0xff00 -> {
+                        if(asmgen.isTargetCpu(CpuType.CPU65c02))
+                            asmgen.out("  stz  $name")
+                        else
+                            asmgen.out("  lda  #0 |  sta  $name")
+                    }
                     value and 255 == 0 -> {
                         if(asmgen.isTargetCpu(CpuType.CPU65c02))
                             asmgen.out("  stz  $name")
@@ -1033,33 +1158,38 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
 +""")
                         else
                             asmgen.out("""
-                                ldy  #0
+                                ldy  #255
                                 lda  $otherName
                                 bpl  +
-                                dey     ; sign extend
-+                               sty  P8ZP_SCRATCH_B1
-                                lda  $name
+                                iny     ; sign extend
++                               eor  #255
                                 sec
-                                sbc  $otherName
+                                adc  $name
                                 sta  $name
-                                lda  $name+1
-                                sbc  P8ZP_SCRATCH_B1
+                                tya
+                                adc  $name+1
                                 sta  $name+1""")
                     }
                     "*" -> {
-                        asmgen.out("  lda  $otherName |  sta  P8ZP_SCRATCH_W1")
-                        if(asmgen.isTargetCpu(CpuType.CPU65c02))
-                            asmgen.out("  stz  P8ZP_SCRATCH_W1+1")
-                        else
-                            asmgen.out("  lda  #0 |  sta  P8ZP_SCRATCH_W1+1")
+                        if(valueDt==DataType.UBYTE) {
+                            asmgen.out("  lda  $otherName |  sta  P8ZP_SCRATCH_W1")
+                            if(asmgen.isTargetCpu(CpuType.CPU65c02))
+                                asmgen.out("  stz  P8ZP_SCRATCH_W1+1")
+                            else
+                                asmgen.out("  lda  #0 |  sta  P8ZP_SCRATCH_W1+1")
+                        } else {
+                            asmgen.out("  lda  $otherName")
+                            asmgen.signExtendAYlsb(valueDt)
+                            asmgen.out("  sta  P8ZP_SCRATCH_W1 |  sty  P8ZP_SCRATCH_W1+1")
+                        }
                         asmgen.out("""
-                            lda  $name
-                            ldy  $name+1
-                            jsr  math.multiply_words
-                            lda  math.multiply_words.result
-                            sta  $name
-                            lda  math.multiply_words.result+1
-                            sta  $name+1""")
+                                lda  $name
+                                ldy  $name+1
+                                jsr  math.multiply_words
+                                lda  math.multiply_words.result
+                                sta  $name
+                                lda  math.multiply_words.result+1
+                                sta  $name+1""")
                     }
                     "/" -> {
                         if(dt==DataType.UWORD) {
@@ -1103,7 +1233,8 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                             sta  $name
                             lda  P8ZP_SCRATCH_W2+1
                             sta  $name+1
-                        """)                    }
+                        """)
+                    }
                     "<<" -> {
                         asmgen.out("""
                         ldy  $otherName
@@ -1235,9 +1366,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
         // because the value is evaluated onto the eval stack (=slow).
 
         val valueiDt = value.inferType(program)
-        if(!valueiDt.isKnown)
-            throw AssemblyError("unknown dt")
-        val valueDt = valueiDt.getOr(DataType.UNDEFINED)
+        val valueDt = valueiDt.getOrElse { throw AssemblyError("unknown dt") }
 
         fun multiplyVarByWordInAY() {
             asmgen.out("""
@@ -1316,29 +1445,28 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                                 sta  $name+1""")
                     }
                     "-" -> {
-                        asmgen.assignExpressionToVariable(value, "P8ZP_SCRATCH_REG", valueDt, null)
+                        asmgen.assignExpressionToVariable(value, "P8ZP_SCRATCH_B1", valueDt, null)
                         if(valueDt==DataType.UBYTE)
                             asmgen.out("""
                                 lda  $name
                                 sec
-                                sbc  P8ZP_SCRATCH_REG
+                                sbc  P8ZP_SCRATCH_B1
                                 sta  $name
                                 bcs  +
                                 dec  $name+1
 +""")
                         else
                             asmgen.out("""
-                                ldy  #0
-                                lda  P8ZP_SCRATCH_REG
+                                ldy  #255
+                                lda  P8ZP_SCRATCH_B1
                                 bpl  +
-                                dey         ; sign extend
-+                               sty  P8ZP_SCRATCH_B1
-                                lda  $name
+                                iny         ; sign extend
++                               eor  #255
                                 sec
-                                sbc  P8ZP_SCRATCH_REG
+                                adc  $name
                                 sta  $name
-                                lda  $name+1
-                                sbc  P8ZP_SCRATCH_B1
+                                tya
+                                adc  $name+1
                                 sta  $name+1""")
                     }
                     "*" -> {
@@ -1462,14 +1590,6 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
         asmgen.assignExpressionToRegister(value, RegisterOrPair.FAC1)
         asmgen.saveRegisterLocal(CpuRegister.X, scope)
         when (operator) {
-            "**" -> {
-                asmgen.out("""
-                    lda  #<$name
-                    ldy  #>$name
-                    jsr  floats.CONUPK
-                    jsr  floats.FPWRT
-                """)
-            }
             "+" -> {
                 asmgen.out("""
                     lda  #<$name
@@ -1516,28 +1636,6 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
         val otherName = asmgen.asmVariableName(ident)
         asmgen.saveRegisterLocal(CpuRegister.X, scope)
         when (operator) {
-            "**" -> {
-                if(asmgen.haveFPWR()) {
-                    asmgen.out("""
-                        lda  #<$name
-                        ldy  #>$name
-                        jsr  floats.CONUPK
-                        lda  #<$otherName
-                        ldy  #>$otherName
-                        jsr  floats.FPWR
-                    """)
-                } else
-                    // cx16 doesn't have FPWR() only FPWRT()
-                    asmgen.out("""
-                        lda  #<$name
-                        ldy  #>$name
-                        jsr  floats.CONUPK
-                        lda  #<$otherName
-                        ldy  #>$otherName
-                        jsr  floats.MOVFM
-                        jsr  floats.FPWRT
-                    """)
-            }
             "+" -> {
                 asmgen.out("""
                     lda  #<$name
@@ -1590,31 +1688,9 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
     }
 
     private fun inplaceModification_float_litval_to_variable(name: String, operator: String, value: Double, scope: Subroutine) {
-        val constValueName = asmgen.getFloatAsmConst(value)
+        val constValueName = allocator.getFloatAsmConst(value)
         asmgen.saveRegisterLocal(CpuRegister.X, scope)
         when (operator) {
-            "**" -> {
-                if(asmgen.haveFPWR()) {
-                    asmgen.out("""
-                        lda  #<$name
-                        ldy  #>$name
-                        jsr  floats.CONUPK
-                        lda  #<$constValueName
-                        ldy  #>$constValueName
-                        jsr  floats.FPWR
-                    """)
-                } else
-                    // cx16 doesn't have FPWR() only FPWRT()
-                    asmgen.out("""
-                        lda  #<$name
-                        ldy  #>$name
-                        jsr  floats.CONUPK
-                        lda  #<$constValueName
-                        ldy  #>$constValueName
-                        jsr  floats.MOVFM
-                        jsr  floats.FPWRT
-                    """)
-            }
             "+" -> {
                 if (value == 0.0)
                     return
@@ -1739,8 +1815,8 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     TargetStorageKind.MEMORY -> {
                         val mem = target.memory!!
                         when (mem.addressExpression) {
-                            is NumericLiteralValue -> {
-                                val addr = (mem.addressExpression as NumericLiteralValue).number.toHex()
+                            is NumericLiteral -> {
+                                val addr = (mem.addressExpression as NumericLiteral).number.toHex()
                                 asmgen.out("""
                                     lda  $addr
                                     beq  +
@@ -1754,17 +1830,16 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                                     beq  +
                                     lda  #1
 +                                   eor  #1""")
-                                asmgen.out("  sta  ($sourceName),y")
+                                asmgen.storeAIntoZpPointerVar(sourceName)
                             }
                             else -> {
                                 asmgen.assignExpressionToVariable(mem.addressExpression, "P8ZP_SCRATCH_W2", DataType.UWORD, target.scope)
+                                asmgen.loadAFromZpPointerVar("P8ZP_SCRATCH_W2")
                                 asmgen.out("""
-                                    ldy  #0
-                                    lda  (P8ZP_SCRATCH_W2),y
                                     beq  +
                                     lda  #1
-+                                   eor  #1                                    
-                                    sta  (P8ZP_SCRATCH_W2),y""")
++                                   eor  #1""")
+                                asmgen.storeAIntoZpPointerVar("P8ZP_SCRATCH_W2")
                             }
                         }
                     }
@@ -1774,24 +1849,24 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                                 cmp  #0
                                 beq  +
                                 lda  #1
-    +                           eor  #1""")
++                               eor  #1""")
                             RegisterOrPair.X -> asmgen.out("""
                                 txa
                                 beq  +
                                 lda  #1
-    +                           eor  #1
++                               eor  #1
                                 tax""")
                             RegisterOrPair.Y -> asmgen.out("""
                                 tya
                                 beq  +
                                 lda  #1
-    +                           eor  #1
++                               eor  #1
                                 tay""")
                             else -> throw AssemblyError("invalid reg dt for byte not")
                         }
                     }
-                    TargetStorageKind.STACK -> TODO("missing codegen for byte stack not")
-                    else -> throw AssemblyError("missing codegen for in-place not of ubyte ${target.kind}")
+                    TargetStorageKind.STACK -> TODO("no asm gen for byte stack not")
+                    else -> throw AssemblyError("no asm gen for in-place not of ubyte ${target.kind}")
                 }
             }
             DataType.UWORD -> {
@@ -1843,13 +1918,12 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
         +                           ldx  #1
         +""")
                             }
-                            in Cx16VirtualRegisters -> TODO()
+                            in Cx16VirtualRegisters -> throw AssemblyError("cx16 virtual regs should be variables, not real registers")
                             else -> throw AssemblyError("invalid reg dt for word not")
                         }
                     }
-                    TargetStorageKind.MEMORY -> TODO("no asm gen for uword-memory not")
-                    TargetStorageKind.STACK -> TODO("missing codegen for word stack not")
-                    else -> throw AssemblyError("missing codegen for in-place not of uword for ${target.kind}")
+                    TargetStorageKind.STACK -> TODO("no asm gen for word stack not")
+                    else -> throw AssemblyError("no asm gen for in-place not of uword for ${target.kind}")
                 }
             }
             else -> throw AssemblyError("boolean-not of invalid type")
@@ -1869,8 +1943,8 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     TargetStorageKind.MEMORY -> {
                         val memory = target.memory!!
                         when (memory.addressExpression) {
-                            is NumericLiteralValue -> {
-                                val addr = (memory.addressExpression as NumericLiteralValue).number.toHex()
+                            is NumericLiteral -> {
+                                val addr = (memory.addressExpression as NumericLiteral).number.toHex()
                                 asmgen.out("""
                                     lda  $addr
                                     eor  #255
@@ -1886,8 +1960,8 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                                 asmgen.out("""
                                     ldy  #0
                                     lda  (P8ZP_SCRATCH_W2),y
-                                    eor  #255
-                                    sta  (P8ZP_SCRATCH_W2),y""")
+                                    eor  #255""")
+                                asmgen.storeAIntoZpPointerVar("P8ZP_SCRATCH_W2")
                             }
                         }
                     }
@@ -1899,8 +1973,8 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                             else -> throw AssemblyError("invalid reg dt for byte invert")
                         }
                     }
-                    TargetStorageKind.STACK -> TODO("missing codegen for byte stack invert")
-                    else -> throw AssemblyError("missing codegen for in-place invert ubyte for ${target.kind}")
+                    TargetStorageKind.STACK -> TODO("no asm gen for byte stack invert")
+                    else -> throw AssemblyError("no asm gen for in-place invert ubyte for ${target.kind}")
                 }
             }
             DataType.UWORD -> {
@@ -1919,15 +1993,12 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                             RegisterOrPair.AX -> asmgen.out("  pha |  txa |  eor  #255 |  tax |  pla |  eor  #255")
                             RegisterOrPair.AY -> asmgen.out("  pha |  tya |  eor  #255 |  tay |  pla |  eor  #255")
                             RegisterOrPair.XY -> asmgen.out("  txa |  eor  #255 |  tax |  tya |  eor  #255 |  tay")
-                            in Cx16VirtualRegisters -> {
-                                TODO("codegen for cx16 word register invert")
-                            }
+                            in Cx16VirtualRegisters -> throw AssemblyError("cx16 virtual regs should be variables, not real registers")
                             else -> throw AssemblyError("invalid reg dt for word invert")
                         }
                     }
-                    TargetStorageKind.MEMORY -> TODO("no asm gen for uword-memory invert")
-                    TargetStorageKind.STACK -> TODO("missing codegen for word stack invert")
-                    else -> throw AssemblyError("missing codegen for in-place invert uword for ${target.kind}")
+                    TargetStorageKind.STACK -> TODO("no asm gen for word stack invert")
+                    else -> throw AssemblyError("no asm gen for in-place invert uword for ${target.kind}")
                 }
             }
             else -> throw AssemblyError("invert of invalid type")
@@ -1947,15 +2018,21 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     }
                     TargetStorageKind.REGISTER -> {
                         when(target.register!!) {
-                            RegisterOrPair.A -> asmgen.out("  sta  P8ZP_SCRATCH_B1 |  lda  #0 |  sec |  sbc  P8ZP_SCRATCH_B1")
-                            RegisterOrPair.X -> asmgen.out("  stx  P8ZP_SCRATCH_B1 |  lda  #0 |  sec |  sbc  P8ZP_SCRATCH_B1 |  tax")
-                            RegisterOrPair.Y -> asmgen.out("  sty  P8ZP_SCRATCH_B1 |  lda  #0 |  sec |  sbc  P8ZP_SCRATCH_B1 |  tay")
+                            RegisterOrPair.A -> {
+                                if(asmgen.isTargetCpu(CpuType.CPU65c02))
+                                    asmgen.out("  eor  #255 |  ina")
+                                else
+                                    asmgen.out("  eor  #255 |  clc |  adc  #1")
+
+                            }
+                            RegisterOrPair.X -> asmgen.out("  txa |  eor  #255 |  tax |  inx")
+                            RegisterOrPair.Y -> asmgen.out("  tya |  eor  #255 |  tay |  iny")
                             else -> throw AssemblyError("invalid reg dt for byte negate")
                         }
                     }
-                    TargetStorageKind.MEMORY -> TODO("can't in-place negate memory ubyte")
-                    TargetStorageKind.STACK -> TODO("missing codegen for byte stack negate")
-                    else -> throw AssemblyError("missing codegen for in-place negate byte array")
+                    TargetStorageKind.MEMORY -> throw AssemblyError("memory is ubyte, can't in-place negate")
+                    TargetStorageKind.STACK -> TODO("no asm gen for byte stack negate")
+                    else -> throw AssemblyError("no asm gen for in-place negate byte")
                 }
             }
             DataType.WORD -> {
@@ -1974,51 +2051,46 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                         when(target.register!!) { //P8ZP_SCRATCH_REG
                             RegisterOrPair.AX -> {
                                 asmgen.out("""
-                                    sta  P8ZP_SCRATCH_REG
-                                    stx  P8ZP_SCRATCH_REG+1
-                                    lda  #0
                                     sec
-                                    sbc  P8ZP_SCRATCH_REG
+                                    eor  #255
+                                    adc  #0
                                     pha
-                                    lda  #0
-                                    sbc  P8ZP_SCRATCH_REG+1
+                                    txa
+                                    eor  #255
+                                    adc  #0
                                     tax
                                     pla""")
                             }
                             RegisterOrPair.AY -> {
                                 asmgen.out("""
-                                    sta  P8ZP_SCRATCH_REG
-                                    sty  P8ZP_SCRATCH_REG+1
-                                    lda  #0
                                     sec
-                                    sbc  P8ZP_SCRATCH_REG
+                                    eor  #255
+                                    adc  #0
                                     pha
-                                    lda  #0
-                                    sbc  P8ZP_SCRATCH_REG+1
+                                    tya
+                                    eor  #255
+                                    adc  #0
                                     tay
                                     pla""")
                             }
                             RegisterOrPair.XY -> {
                                 asmgen.out("""
-                                    stx  P8ZP_SCRATCH_REG
-                                    sty  P8ZP_SCRATCH_REG+1
-                                    lda  #0
                                     sec
-                                    sbc  P8ZP_SCRATCH_REG
+                                    txa
+                                    eor  #255
+                                    adc  #0
                                     tax
-                                    lda  #0
-                                    sbc  P8ZP_SCRATCH_REG+1
+                                    tya
+                                    eor  #255
+                                    adc  #0
                                     tay""")
                             }
-                            in Cx16VirtualRegisters -> {
-                                TODO("codegen for cx16 word register negate")
-                            }
+                            in Cx16VirtualRegisters -> throw AssemblyError("cx16 virtual regs should be variables, not real registers")
                             else -> throw AssemblyError("invalid reg dt for word neg")
                         }
                     }
-                    TargetStorageKind.MEMORY -> TODO("no asm gen for word memory negate")
-                    TargetStorageKind.STACK -> TODO("missing codegen for word stack negate")
-                    else -> throw AssemblyError("missing codegen for in-place negate word array")
+                    TargetStorageKind.STACK -> TODO("no asm gen for word stack negate")
+                    else -> throw AssemblyError("no asm gen for in-place negate word")
                 }
             }
             DataType.FLOAT -> {
@@ -2031,13 +2103,11 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                             sta  ${target.asmVarname}+1
                         """)
                     }
-                    TargetStorageKind.REGISTER -> TODO("missing codegen for float reg negate")
-                    TargetStorageKind.MEMORY -> TODO("missing codegen for float memory negate")
-                    TargetStorageKind.STACK -> TODO("missing codegen for stack float negate")
+                    TargetStorageKind.STACK -> TODO("no asm gen for float stack negate")
                     else -> throw AssemblyError("weird target kind for inplace negate float ${target.kind}")
                 }
             }
-            else -> throw AssemblyError("negate of invalid type")
+            else -> throw AssemblyError("negate of invalid type $dt")
         }
     }
 

codeGenExperimental/build.gradle

@@ -0,0 +1,46 @@
+
+plugins {
+    id 'java'
+    id 'application'
+    id "org.jetbrains.kotlin.jvm"
+}
+
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(javaVersion)
+    }
+}
+
+compileKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+compileTestKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+dependencies {
+    implementation project(':codeAst')
+    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:1.1.14"
+
+}
+
+sourceSets {
+    main {
+        java {
+            srcDirs = ["${project.projectDir}/src"]
+        }
+        resources {
+            srcDirs = ["${project.projectDir}/res"]
+        }
+    }
+}
+
+// note: there are no unit tests in this module!

codeGenExperimental/codeGenExperimental.iml

@@ -0,0 +1,16 @@
+<?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" />
+    <orderEntry type="module" module-name="codeAst" />
+    <orderEntry type="module" module-name="codeCore" />
+  </component>
+</module>

codeGenExperimental/src/prog8/codegen/experimental/AsmGen.kt

@@ -0,0 +1,39 @@
+package prog8.codegen.experimental
+
+import prog8.code.SymbolTable
+import prog8.code.ast.PtProgram
+import prog8.code.core.CompilationOptions
+import prog8.code.core.IAssemblyGenerator
+import prog8.code.core.IAssemblyProgram
+import prog8.code.core.IErrorReporter
+
+/*
+
+    NOTE: The goal is to keep the dependencies as lean as possible! For now, we depend only on:
+         - codeAst (the 'lean' new AST and the SymbolTable)
+         - codeCore (various base enums and interfaces)
+
+    This *should* be enough to build a complete code generator with. But we'll see :)
+
+ */
+
+
+class AsmGen(internal val program: PtProgram,
+             internal val symbolTable: SymbolTable,
+             internal val options: CompilationOptions,
+             internal val errors: IErrorReporter
+): IAssemblyGenerator {
+
+    override fun compileToAssembly(): IAssemblyProgram? {
+
+        println("\n** experimental code generator **\n")
+
+        println("Writing AST into XML form...")
+        val xmlConv = AstToXmlConverter(program, symbolTable, options)
+        xmlConv.writeXml()
+
+        println("..todo: create assembly program into ${options.outputDir.toAbsolutePath()}..")
+
+        return AssemblyProgram("dummy")
+    }
+}

codeGenExperimental/src/prog8/codegen/experimental/AssemblyProgram.kt

@@ -0,0 +1,13 @@
+package prog8.codegen.experimental
+
+import prog8.code.core.CompilationOptions
+import prog8.code.core.IAssemblyProgram
+
+
+internal class AssemblyProgram(override val name: String) : IAssemblyProgram
+{
+    override fun assemble(options: CompilationOptions): Boolean {
+        println("..todo: assemble code into binary..")
+        return true
+    }
+}

codeGenExperimental/src/prog8/codegen/experimental/AstToXmlConverter.kt

@@ -0,0 +1,667 @@
+package prog8.codegen.experimental
+
+import prog8.code.*
+import prog8.code.ast.*
+import prog8.code.core.*
+import javax.xml.stream.XMLOutputFactory
+import kotlin.io.path.Path
+import kotlin.io.path.absolutePathString
+import kotlin.io.path.div
+
+/*
+
+    NOTE: The goal is to keep the dependencies as lean as possible! For now, we depend only on:
+         - codeAst (the 'lean' new AST and the SymbolTable)
+         - codeCore (various base enums and interfaces)
+
+    This *should* be enough to build a complete code generator with. But we'll see :)
+
+ */
+
+
+class AstToXmlConverter(internal val program: PtProgram,
+                        internal val symbolTable: SymbolTable,
+                        internal val options: CompilationOptions
+) {
+
+    private lateinit var xml: IndentingXmlWriter
+
+    fun writeXml() {
+        val writer = (options.outputDir / Path(program.name+"-ast.xml")).toFile().printWriter()
+        xml = IndentingXmlWriter(XMLOutputFactory.newFactory().createXMLStreamWriter(writer))
+        xml.doc()
+        xml.elt("program")
+        xml.attr("name", program.name)
+        xml.startChildren()
+        writeOptions(options)
+        program.children.forEach { writeNode(it) }
+        writeSymboltable(symbolTable)
+        xml.endElt()
+        xml.endDoc()
+        xml.close()
+    }
+
+    private fun writeSymboltable(st: SymbolTable) {
+        xml.elt("symboltable")
+        xml.startChildren()
+        st.flat.forEach{ (name, entry) ->
+            xml.elt("entry")
+            xml.attr("name", name.joinToString("."))
+            xml.attr("type", entry.type.name)
+            xml.startChildren()
+            writeStNode(entry)
+            xml.endElt()
+        }
+        xml.endElt()
+    }
+
+    private fun writeStNode(node: StNode) {
+        when(node.type) {
+            StNodeType.GLOBAL,
+            StNodeType.LABEL,
+            StNodeType.BLOCK,
+            StNodeType.BUILTINFUNC,
+            StNodeType.SUBROUTINE -> {/* no additional info*/}
+            StNodeType.ROMSUB -> {
+                node as StRomSub
+                xml.elt("romsub")
+                xml.attr("address", node.address.toString())
+                xml.endElt()
+            }
+            StNodeType.STATICVAR -> {
+                node as StStaticVariable
+                xml.elt("var")
+                xml.attr("type", node.dt.name)
+                xml.attr("zpwish", node.zpwish.name)
+                if(node.length!=null)
+                    xml.attr("length", node.length.toString())
+                if(node.initialNumericValue!=null || node.initialArrayValue!=null || node.initialStringValue!=null) {
+                    xml.startChildren()
+                    if(node.initialNumericValue!=null) {
+                        writeNumber(node.dt, node.initialNumericValue!!)
+                    }
+                    if(node.initialStringValue!=null) {
+                        xml.writeTextNode(
+                            "string",
+                            listOf(Pair("encoding", node.initialStringValue!!.second.name)),
+                            node.initialStringValue!!.first,
+                            false
+                        )
+                    }
+                    if(node.initialArrayValue!=null) {
+                        xml.elt("array")
+                        xml.startChildren()
+                        val eltDt = ArrayToElementTypes.getValue(node.dt)
+                        node.initialArrayValue!!.forEach {
+                            if(it.number!=null) {
+                                writeNumber(eltDt, it.number!!)
+                            }
+                            if(it.addressOf!=null) {
+                                xml.elt("addressof")
+                                xml.attr("symbol", it.addressOf!!.joinToString("."))
+                                xml.endElt()
+                            }
+                        }
+                        xml.endElt()
+                    }
+                }
+                xml.endElt()
+            }
+            StNodeType.MEMVAR -> {
+                node as StMemVar
+                xml.writeTextNode("memvar",
+                    listOf(Pair("type", node.dt.name)),
+                    node.address.toString(),
+                    false)
+            }
+            StNodeType.CONSTANT -> {
+                node as StConstant
+                xml.writeTextNode("const",
+                    listOf(Pair("type", node.dt.name)),
+                    intOrDouble(node.dt, node.value).toString(),
+                    false)
+            }
+        }
+    }
+
+    private fun writeOptions(options: CompilationOptions) {
+        xml.elt("options")
+        xml.attr("target", options.compTarget.name)
+        xml.attr("output", options.output.name)
+        xml.attr("launcher", options.launcher.name)
+        xml.attr("zeropage", options.zeropage.name)
+        xml.attr("loadaddress", options.loadAddress.toString())
+        xml.attr("floatsenabled", options.floats.toString())
+        xml.attr("nosysinit", options.noSysInit.toString())
+        xml.attr("dontreinitglobals", options.dontReinitGlobals.toString())
+        xml.attr("optimize", options.optimize.toString())
+        if(options.zpReserved.isNotEmpty()) {
+            xml.startChildren()
+            options.zpReserved.forEach {
+                xml.elt("zpreserved")
+                xml.attr("from", it.first.toString())
+                xml.attr("to", it.last.toString())
+                xml.endElt()
+            }
+        }
+        xml.endElt()
+    }
+
+    private fun writeNode(it: PtNode) {
+        when(it) {
+            is PtBlock -> write(it)
+            is PtSub -> write(it)
+            is PtVariable -> write(it)
+            is PtAssignment -> write(it)
+            is PtConstant -> write(it)
+            is PtAsmSub -> write(it)
+            is PtAddressOf -> write(it)
+            is PtArrayIndexer -> write(it)
+            is PtArray -> write(it)
+            is PtBinaryExpression -> write(it)
+            is PtBuiltinFunctionCall -> write(it)
+            is PtConditionalBranch -> write(it)
+            is PtContainmentCheck -> write(it)
+            is PtForLoop -> write(it)
+            is PtFunctionCall -> write(it)
+            is PtIdentifier -> write(it)
+            is PtIfElse -> write(it)
+            is PtInlineAssembly -> write(it)
+            is PtIncludeBinary -> write(it)
+            is PtJump -> write(it)
+            is PtMemoryByte -> write(it)
+            is PtMemMapped -> write(it)
+            is PtNumber -> write(it)
+            is PtPipe -> write(it)
+            is PtPostIncrDecr -> write(it)
+            is PtPrefix -> write(it)
+            is PtRange -> write(it)
+            is PtRepeatLoop -> write(it)
+            is PtReturn -> write(it)
+            is PtString -> write(it)
+            is PtTypeCast -> write(it)
+            is PtWhen -> write(it)
+            is PtWhenChoice -> write(it)
+            is PtLabel -> write(it)
+            is PtNop -> {}
+            is PtBreakpoint -> write(it)
+            is PtScopeVarsDecls -> write(it)
+            is PtNodeGroup -> it.children.forEach { writeNode(it) }
+            else -> TODO("$it")
+        }
+    }
+
+    private fun write(vars: PtScopeVarsDecls) {
+        xml.elt("vars")
+        xml.startChildren()
+        vars.children.forEach { writeNode(it) }
+        xml.endElt()
+    }
+
+    private fun write(breakPt: PtBreakpoint) {
+        xml.elt("breakpoint")
+        xml.pos(breakPt.position)
+        xml.endElt()
+    }
+
+    private fun write(pipe: PtPipe) {
+        xml.elt("pipe")
+        xml.attr("type", pipe.type.name)
+        xml.startChildren()
+        pipe.children.forEach { writeNode(it) }
+        xml.endElt()
+    }
+
+    private fun write(array: PtArray) {
+        xml.elt("array")
+        xml.attr("type", array.type.name)
+        xml.startChildren()
+        array.children.forEach { writeNode(it) }
+        xml.endElt()
+    }
+
+    private fun write(prefix: PtPrefix) {
+        xml.elt("prefix")
+        xml.attr("op", prefix.operator)
+        xml.attr("type", prefix.type.name)
+        xml.startChildren()
+        xml.elt("value")
+        xml.startChildren()
+        writeNode(prefix.value)
+        xml.endElt()
+        xml.endElt()
+    }
+
+    private fun write(string: PtString) =
+        xml.writeTextNode("string", listOf(Pair("encoding", string.encoding.name)), string.value, false)
+
+    private fun write(rept: PtRepeatLoop) {
+        xml.elt("repeat")
+        xml.pos(rept.position)
+        xml.startChildren()
+        xml.elt("count")
+        xml.startChildren()
+        writeNode(rept.count)
+        xml.endElt()
+        writeNode(rept.statements)
+        xml.endElt()
+    }
+
+    private fun write(branch: PtConditionalBranch) {
+        xml.elt("conditionalbranch")
+        xml.attr("condition", branch.condition.name)
+        xml.pos(branch.position)
+        xml.startChildren()
+        xml.elt("true")
+        xml.startChildren()
+        writeNode(branch.trueScope)
+        xml.endElt()
+        if(branch.falseScope.children.isNotEmpty()) {
+            xml.elt("false")
+            xml.startChildren()
+            writeNode(branch.falseScope)
+            xml.endElt()
+        }
+        xml.endElt()
+    }
+
+    private fun write(check: PtContainmentCheck) {
+        xml.elt("containment")
+        xml.attr("type", check.type.name)
+        xml.startChildren()
+        xml.elt("element")
+        xml.startChildren()
+        writeNode(check.children[0])
+        xml.endElt()
+        xml.elt("iterable")
+        xml.startChildren()
+        writeNode(check.children[1])
+        xml.endElt()
+        xml.endElt()
+    }
+
+    private fun write(range: PtRange) {
+        xml.elt("range")
+        xml.attr("type", range.type.name)
+        xml.startChildren()
+        xml.elt("from")
+        xml.startChildren()
+        writeNode(range.from)
+        xml.endElt()
+        xml.elt("to")
+        xml.startChildren()
+        writeNode(range.to)
+        xml.endElt()
+        xml.elt("step")
+        xml.startChildren()
+        writeNode(range.step)
+        xml.endElt()
+        xml.endElt()
+    }
+
+    private fun write(forLoop: PtForLoop) {
+        xml.elt("for")
+        xml.attr("loopvar", strTargetName(forLoop.variable))
+        xml.pos(forLoop.position)
+        xml.startChildren()
+        xml.elt("iterable")
+        xml.startChildren()
+        writeNode(forLoop.iterable)
+        xml.endElt()
+        writeNode(forLoop.statements)
+        xml.endElt()
+    }
+
+    private fun write(membyte: PtMemoryByte) {
+        xml.elt("membyte")
+        xml.attr("type", membyte.type.name)
+        xml.startChildren()
+        xml.elt("address")
+        xml.startChildren()
+        writeNode(membyte.address)
+        xml.endElt()
+        xml.endElt()
+    }
+
+    private fun write(whenStmt: PtWhen) {
+        xml.elt("when")
+        xml.pos(whenStmt.position)
+        xml.startChildren()
+        xml.elt("value")
+        xml.startChildren()
+        writeNode(whenStmt.value)
+        xml.endElt()
+        xml.elt("choices")
+        xml.startChildren()
+        writeNode(whenStmt.choices)
+        xml.endElt()
+        xml.endElt()
+    }
+
+    private fun write(choice: PtWhenChoice) {
+        xml.elt("choice")
+        if(choice.isElse) {
+            xml.attr("else", "true")
+            xml.startChildren()
+        } else {
+            xml.startChildren()
+            xml.elt("values")
+            xml.startChildren()
+            writeNode(choice.values)
+            xml.endElt()
+        }
+        writeNode(choice.statements)
+        xml.endElt()
+    }
+
+    private fun write(inlineAsm: PtInlineAssembly) {
+        xml.elt("assembly")
+        xml.pos(inlineAsm.position)
+        xml.startChildren()
+        xml.writeTextNode("code", emptyList(), inlineAsm.assembly)
+        xml.endElt()
+    }
+
+    private fun write(inlineBinary: PtIncludeBinary) {
+        xml.elt("binary")
+        xml.attr("filename", inlineBinary.file.absolutePathString())
+        if(inlineBinary.offset!=null)
+            xml.attr("offset", inlineBinary.offset!!.toString())
+        if(inlineBinary.length!=null)
+            xml.attr("length", inlineBinary.length!!.toString())
+        xml.pos(inlineBinary.position)
+        xml.endElt()
+    }
+
+    private fun write(fcall: PtBuiltinFunctionCall) {
+        xml.elt("builtinfcall")
+        xml.attr("name", fcall.name)
+        if(fcall.void)
+            xml.attr("type", "VOID")
+        else
+            xml.attr("type", fcall.type.name)
+        xml.startChildren()
+        fcall.children.forEach { writeNode(it) }
+        xml.endElt()
+    }
+
+    private fun write(cast: PtTypeCast) {
+        xml.elt("cast")
+        xml.attr("type", cast.type.name)
+        xml.startChildren()
+        writeNode(cast.value)
+        xml.endElt()
+    }
+
+    private fun write(aix: PtArrayIndexer) {
+        xml.elt("arrayindexed")
+        xml.attr("type", aix.type.name)
+        xml.startChildren()
+        write(aix.variable)
+        writeNode(aix.index)
+        xml.endElt()
+    }
+
+    private fun write(binexpr: PtBinaryExpression) {
+        xml.elt("binexpr")
+        xml.attr("op", binexpr.operator)
+        xml.attr("type", binexpr.type.name)
+        xml.startChildren()
+        writeNode(binexpr.left)
+        writeNode(binexpr.right)
+        xml.endElt()
+    }
+
+    private fun write(addrof: PtAddressOf) {
+        xml.elt("addressof")
+        xml.attr("symbol", strTargetName(addrof.identifier))
+        xml.endElt()
+    }
+
+    private fun write(fcall: PtFunctionCall) {
+        xml.elt("fcall")
+        xml.attr("name", strTargetName(fcall))
+        if(fcall.void)
+            xml.attr("type", "VOID")
+        else
+            xml.attr("type", fcall.type.name)
+        xml.pos(fcall.position)
+        xml.startChildren()
+        fcall.children.forEach { writeNode(it) }
+        xml.endElt()
+    }
+
+    private fun write(number: PtNumber) = writeNumber(number.type, number.number)
+
+    private fun writeNumber(type: DataType, number: Double) =
+        xml.writeTextNode("number", listOf(Pair("type", type.name)), intOrDouble(type, number).toString(), false)
+
+    private fun write(symbol: PtIdentifier) {
+        xml.elt("symbol")
+        xml.attr("name", strTargetName(symbol))
+        xml.attr("type", symbol.type.name)
+        xml.endElt()
+    }
+
+    private fun write(assign: PtAssignment) {
+        xml.elt("assign")
+        xml.attr("aug", assign.augmentable.toString())
+        xml.pos(assign.position)
+        xml.startChildren()
+        write(assign.target)
+        writeNode(assign.value)
+        xml.endElt()
+    }
+
+    private fun write(ifElse: PtIfElse) {
+        xml.elt("ifelse")
+        xml.pos(ifElse.position)
+        xml.startChildren()
+        xml.elt("condition")
+        xml.startChildren()
+        writeNode(ifElse.condition)
+        xml.endElt()
+        xml.elt("true")
+        xml.pos(ifElse.ifScope.position)
+        xml.startChildren()
+        writeNode(ifElse.ifScope)
+        xml.endElt()
+        if(ifElse.elseScope.children.isNotEmpty()) {
+            xml.elt("false")
+            xml.pos(ifElse.elseScope.position)
+            xml.startChildren()
+            writeNode(ifElse.elseScope)
+            xml.endElt()
+        }
+        xml.endElt()
+    }
+
+    private fun write(ret: PtReturn) {
+        xml.elt("return")
+        if(ret.hasValue) {
+            xml.startChildren()
+            writeNode(ret.value!!)
+        }
+        xml.endElt()
+    }
+
+    private fun write(incdec: PtPostIncrDecr) {
+        if(incdec.operator=="++") xml.elt("inc") else xml.elt("dec")
+        xml.startChildren()
+        write(incdec.target)
+        xml.endElt()
+    }
+
+    private fun write(label: PtLabel) {
+        xml.elt("label")
+        xml.attr("name", label.scopedName.joinToString("."))
+        xml.pos(label.position)
+        xml.endElt()
+    }
+
+    private fun write(block: PtBlock) {
+        xml.elt("block")
+        xml.attr("name", block.scopedName.joinToString("."))
+        if(block.address!=null)
+            xml.attr("address", block.address!!.toString())
+        xml.attr("library", block.library.toString())
+        xml.pos(block.position)
+        xml.startChildren()
+        block.children.forEach { writeNode(it) }
+        xml.endElt()
+    }
+
+    private fun write(memMapped: PtMemMapped) {
+        xml.writeTextNode("memvar",
+            listOf(
+                Pair("name", memMapped.scopedName.joinToString(".")),
+                Pair("type", memMapped.type.name)
+            ),
+            memMapped.address.toString(),
+            false)
+    }
+
+    private fun write(target: PtAssignTarget) {
+        xml.elt("target")
+        xml.startChildren()
+        if(target.identifier!=null) {
+            writeNode(target.identifier!!)
+        } else if(target.memory!=null) {
+            writeNode(target.memory!!)
+        } else if(target.array!=null) {
+            writeNode(target.array!!)
+        } else
+            throw InternalCompilerException("weird assign target")
+        xml.endElt()
+    }
+
+    private fun write(jump: PtJump) {
+        xml.elt("jump")
+        if(jump.identifier!=null) xml.attr("symbol", strTargetName(jump.identifier!!))
+        else if(jump.address!=null) xml.attr("address", jump.address!!.toString())
+        else if(jump.generatedLabel!=null) xml.attr("label", jump.generatedLabel!!)
+        else
+            throw InternalCompilerException("weird jump target")
+        xml.endElt()
+    }
+
+    private fun write(sub: PtSub) {
+        xml.elt("sub")
+        xml.attr("name", sub.scopedName.joinToString("."))
+        if(sub.inline)
+            xml.attr("inline", "true")
+        xml.attr("returntype", sub.returntype?.toString() ?: "VOID")
+        xml.pos(sub.position)
+        xml.startChildren()
+        if(sub.parameters.isNotEmpty()) {
+            xml.elt("parameters")
+            xml.startChildren()
+            sub.parameters.forEach { write(it) }
+            xml.endElt()
+        }
+        sub.children.forEach { writeNode(it) }
+        xml.endElt()
+    }
+
+    private fun write(parameter: PtSubroutineParameter, registerOrStatusflag: RegisterOrStatusflag? = null) {
+        xml.elt("param")
+        xml.attr("name", parameter.name)
+        xml.attr("type", parameter.type.name)
+        if(registerOrStatusflag?.statusflag!=null) {
+            xml.attr("statusflag", registerOrStatusflag.statusflag!!.toString())
+        }
+        if(registerOrStatusflag?.registerOrPair!=null){
+            xml.attr("registers", registerOrStatusflag.registerOrPair!!.name)
+        }
+        xml.endElt()
+    }
+
+    private fun write(asmSub: PtAsmSub) {
+        if(asmSub.address!=null) {
+            xml.elt("romsub")
+            xml.attr("name", asmSub.scopedName.joinToString("."))
+            xml.attr("address", asmSub.address!!.toString())
+            if(asmSub.inline)
+                xml.attr("inline", "true")
+            xml.pos(asmSub.position)
+            xml.startChildren()
+            paramsEtcetera(asmSub)
+            xml.endElt()
+        }
+        else {
+            xml.elt("asmsub")
+            xml.attr("name", asmSub.scopedName.joinToString("."))
+            if(asmSub.inline)
+                xml.attr("inline", "true")
+            xml.pos(asmSub.position)
+            xml.startChildren()
+            paramsEtcetera(asmSub)
+            xml.elt("code")
+            xml.startChildren()
+            asmSub.children.forEach { writeNode(it) }
+            xml.endElt()
+            xml.endElt()
+        }
+    }
+
+    private fun paramsEtcetera(asmSub: PtAsmSub) {
+        if(asmSub.parameters.isNotEmpty()) {
+            xml.elt("parameters")
+            xml.startChildren()
+            asmSub.parameters.forEach { (param, reg) -> write(param, reg) }
+            xml.endElt()
+        }
+        if(asmSub.clobbers.isNotEmpty()) {
+            xml.elt("clobbers")
+            xml.attr("registers", asmSub.clobbers.map {it.name}.joinToString(","))
+            xml.endElt()
+        }
+        if(asmSub.retvalRegisters.isNotEmpty()) {
+            xml.elt("returns")
+            xml.startChildren()
+            asmSub.retvalRegisters.forEach {
+                xml.elt("register")
+                if(it.statusflag!=null)
+                    xml.attr("statusflag", it.statusflag!!.toString())
+                if(it.registerOrPair!=null)
+                    xml.attr("registers", it.registerOrPair!!.toString())
+                xml.endElt()
+            }
+            xml.endElt()
+        }
+    }
+
+    private fun write(constant: PtConstant) {
+        xml.writeTextNode("const",
+            listOf(
+                Pair("name", constant.scopedName.joinToString(".")),
+                Pair("type", constant.type.name)
+            ),
+            intOrDouble(constant.type, constant.value).toString(), false)
+    }
+
+    private fun write(variable: PtVariable) {
+        // the variable declaration nodes are still present in the Ast,
+        // but the Symboltable should be used look up their details.
+        xml.elt("vardecl")
+        xml.attr("name", variable.scopedName.joinToString("."))
+        xml.attr("type", variable.type.name)
+        if(variable.arraySize!=null)
+            xml.attr("arraysize", variable.arraySize.toString())
+        if(variable.value!=null) {
+            // static initialization value
+            xml.startChildren()
+            writeNode(variable.value!!)
+        }
+        xml.endElt()
+    }
+
+
+
+    private fun strTargetName(ident: PtIdentifier): String = ident.targetName.joinToString(".")
+
+    private fun strTargetName(call: PtFunctionCall): String = call.functionName.joinToString(".")
+
+    private fun intOrDouble(type: DataType, value: Double): Number =
+        if(type in IntegerDatatypes) value.toInt() else value
+}

codeGenExperimental/src/prog8/codegen/experimental/IndentingXmlWriter.kt

@@ -0,0 +1,89 @@
+package prog8.codegen.experimental
+
+import prog8.code.core.Position
+import java.util.*
+import javax.xml.stream.XMLStreamWriter
+
+class IndentingXmlWriter(val xml: XMLStreamWriter): XMLStreamWriter by xml {
+    private var indent = 0
+    private var content = Stack<Boolean>()
+
+    fun doc(version: String? = null) = if(version==null) writeStartDocument() else writeStartDocument(version)
+    fun endDoc() = writeEndDocument()
+    fun elt(name: String) = writeStartElement(name)
+    fun attr(name: String, value: String) = writeAttribute(name, value)
+    fun attrs(attributes: List<Pair<String, String>>) = attributes.forEach { writeAttribute(it.first, it.second) }
+    fun startChildren() {
+        xml.writeCharacters("\n")
+        content.pop()
+        content.push(true)
+    }
+    fun endElt(writeIndent: Boolean=true) = writeEndElement(writeIndent)
+    fun pos(pos: Position) = writeAttribute("src", pos.toString())
+    fun comment(text: String) {
+        writeComment(text)
+        writeCharacters("\n")
+    }
+
+    override fun writeStartDocument() {
+        xml.writeStartDocument()
+        xml.writeCharacters("\n")
+        content.push(true)
+    }
+
+    override fun writeStartDocument(version: String) {
+        xml.writeStartDocument(version)
+        xml.writeCharacters("\n")
+        content.push(true)
+    }
+
+    override fun writeEndDocument() {
+        xml.writeEndDocument()
+        xml.writeCharacters("\n")
+        require(indent==0)
+        require(content.size==1)
+    }
+
+    override fun writeStartElement(name: String) {
+        xml.writeCharacters("  ".repeat(indent))
+        xml.writeStartElement(name)
+        indent++
+        content.push(false)
+    }
+
+    override fun writeStartElement(name: String, ns: String) {
+        xml.writeCharacters("  ".repeat(indent))
+        xml.writeStartElement(name, ns)
+        indent++
+        content.push(false)
+    }
+
+    fun writeEndElement(writeIndents: Boolean) {
+        indent--
+        if(content.pop() && writeIndents)
+            xml.writeCharacters("  ".repeat(indent))
+        xml.writeEndElement()
+        xml.writeCharacters("\n")
+    }
+
+    override fun writeEndElement() = writeEndElement(true)
+
+    override fun writeStartElement(name: String, ns: String, p2: String) {
+        xml.writeCharacters("  ".repeat(indent))
+        xml.writeStartElement(name, ns, p2)
+        indent++
+        content.push(false)
+    }
+
+    fun writeTextNode(name: String, attrs: List<Pair<String, String>>, text: String, cdata: Boolean = true) {
+        xml.writeCharacters("  ".repeat(indent))
+        xml.writeStartElement(name)
+        attrs.forEach { (name, value) -> xml.writeAttribute(name, value) }
+        if(cdata)
+            xml.writeCData(text)
+        else
+            xml.writeCharacters(text)
+        xml.writeEndElement()
+        xml.writeCharacters("\n")
+    }
+}

codeGenVirtual/build.gradle

@@ -0,0 +1,47 @@
+
+plugins {
+    id 'java'
+    id 'application'
+    id "org.jetbrains.kotlin.jvm"
+}
+
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(javaVersion)
+    }
+}
+
+compileKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+compileTestKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+dependencies {
+    implementation project(':virtualmachine')
+    implementation project(':codeAst')
+    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:1.1.14"
+
+}
+
+sourceSets {
+    main {
+        java {
+            srcDirs = ["${project.projectDir}/src"]
+        }
+        resources {
+            srcDirs = ["${project.projectDir}/res"]
+        }
+    }
+}
+
+// note: there are no unit tests in this module!

codeGenVirtual/codeGenVirtual.iml

@@ -0,0 +1,16 @@
+<?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" />
+    </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" />
+    <orderEntry type="module" module-name="codeAst" />
+    <orderEntry type="module" module-name="codeCore" />
+    <orderEntry type="module" module-name="virtualmachine" />
+  </component>
+</module>

codeGenVirtual/src/prog8/codegen/virtual/AssemblyProgram.kt

@@ -0,0 +1,84 @@
+package prog8.codegen.virtual
+
+import prog8.code.core.CompilationOptions
+import prog8.code.core.IAssemblyProgram
+import prog8.vm.Instruction
+import prog8.vm.Opcode
+import prog8.vm.VmDataType
+import java.io.BufferedWriter
+import kotlin.io.path.bufferedWriter
+import kotlin.io.path.div
+
+
+internal class AssemblyProgram(override val name: String,
+                               private val allocations: VariableAllocator
+) : IAssemblyProgram {
+
+    private val globalInits = mutableListOf<VmCodeLine>()
+    private val blocks = mutableListOf<VmCodeChunk>()
+
+    override fun assemble(options: CompilationOptions): Boolean {
+        val outfile = options.outputDir / ("$name.p8virt")
+        println("write code to $outfile")
+        outfile.bufferedWriter().use { out ->
+            allocations.asVmMemory().forEach { (name, alloc) ->
+                out.write("; ${name.joinToString(".")}\n")
+                out.write(alloc + "\n")
+            }
+            out.write("------PROGRAM------\n")
+
+            out.write("; global var inits\n")
+            globalInits.forEach { out.writeLine(it) }
+
+            out.write("; actual program code\n")
+            blocks.asSequence().flatMap { it.lines }.forEach { line->out.writeLine(line) }
+        }
+        return true
+    }
+
+    private fun BufferedWriter.writeLine(line: VmCodeLine) {
+        when(line) {
+            is VmCodeComment -> write("; ${line.comment}\n")
+            is VmCodeInstruction -> {
+                write(line.ins.toString() + "\n")
+            }
+            is VmCodeLabel -> write("_" + line.name.joinToString(".") + ":\n")
+        }
+    }
+
+    fun addGlobalInits(chunk: VmCodeChunk) = globalInits.addAll(chunk.lines)
+    fun addBlock(block: VmCodeChunk) = blocks.add(block)
+}
+
+internal sealed class VmCodeLine
+
+internal class VmCodeInstruction(
+    opcode: Opcode,
+    type: VmDataType?=null,
+    reg1: Int?=null,        // 0-$ffff
+    reg2: Int?=null,        // 0-$ffff
+    reg3: Int?=null,        // 0-$ffff
+    value: Int?=null,       // 0-$ffff
+    symbol: List<String>?=null    // alternative to value
+    ): VmCodeLine() {
+        val ins = Instruction(opcode, type, reg1, reg2, reg3, value, symbol)
+    }
+internal class VmCodeLabel(val name: List<String>): VmCodeLine()
+internal class VmCodeComment(val comment: String): VmCodeLine()
+
+internal class VmCodeChunk(initial: VmCodeLine? = null) {
+    val lines = mutableListOf<VmCodeLine>()
+
+    init {
+        if(initial!=null)
+            lines.add(initial)
+    }
+
+    operator fun plusAssign(line: VmCodeLine) {
+        lines.add(line)
+    }
+
+    operator fun plusAssign(chunk: VmCodeChunk) {
+        lines.addAll(chunk.lines)
+    }
+}

codeGenVirtual/src/prog8/codegen/virtual/BuiltinFuncGen.kt

@@ -0,0 +1,126 @@
+package prog8.codegen.virtual
+
+import prog8.code.ast.PtBuiltinFunctionCall
+import prog8.code.ast.PtNumber
+import prog8.code.ast.PtString
+import prog8.vm.Opcode
+import prog8.vm.Syscall
+import prog8.vm.VmDataType
+
+internal class BuiltinFuncGen(private val codeGen: CodeGen, private val exprGen: ExpressionGen) {
+
+    fun translate(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk {
+        val code = VmCodeChunk()
+        when(call.name) {
+            "syscall" -> {
+                val vExpr = call.args.single() as PtNumber
+                code += VmCodeInstruction(Opcode.SYSCALL, value=vExpr.number.toInt())
+            }
+            "syscall1" -> {
+                code += VmCodeInstruction(Opcode.PUSH, VmDataType.WORD, reg1 = 0)
+                val callNr = (call.args[0] as PtNumber).number.toInt()
+                code += exprGen.translateExpression(call.args[1], 0)
+                code += VmCodeInstruction(Opcode.SYSCALL, value=callNr)
+                code += VmCodeInstruction(Opcode.POP, VmDataType.WORD, reg1 = 0)
+            }
+            "syscall2" -> {
+                code += VmCodeInstruction(Opcode.PUSH, VmDataType.WORD, reg1 = 0)
+                code += VmCodeInstruction(Opcode.PUSH, VmDataType.WORD, reg1 = 1)
+                while(codeGen.vmRegisters.peekNext()<2) {
+                    codeGen.vmRegisters.nextFree()
+                }
+                val callNr = (call.args[0] as PtNumber).number.toInt()
+                code += exprGen.translateExpression(call.args[1], 0)
+                code += exprGen.translateExpression(call.args[2], 1)
+                code += VmCodeInstruction(Opcode.SYSCALL, value=callNr)
+                code += VmCodeInstruction(Opcode.POP, VmDataType.WORD, reg1 = 1)
+                code += VmCodeInstruction(Opcode.POP, VmDataType.WORD, reg1 = 0)
+            }
+            "syscall3" -> {
+                code += VmCodeInstruction(Opcode.PUSH, VmDataType.WORD, reg1 = 0)
+                code += VmCodeInstruction(Opcode.PUSH, VmDataType.WORD, reg1 = 1)
+                code += VmCodeInstruction(Opcode.PUSH, VmDataType.WORD, reg1 = 2)
+                while(codeGen.vmRegisters.peekNext()<3) {
+                    codeGen.vmRegisters.nextFree()
+                }
+                val callNr = (call.args[0] as PtNumber).number.toInt()
+                code += exprGen.translateExpression(call.args[1], 0)
+                code += exprGen.translateExpression(call.args[2], 1)
+                code += exprGen.translateExpression(call.args[3], 2)
+                code += VmCodeInstruction(Opcode.SYSCALL, value=callNr)
+                code += VmCodeInstruction(Opcode.POP, VmDataType.WORD, reg1 = 2)
+                code += VmCodeInstruction(Opcode.POP, VmDataType.WORD, reg1 = 1)
+                code += VmCodeInstruction(Opcode.POP, VmDataType.WORD, reg1 = 0)
+            }
+            "msb" -> {
+                code += exprGen.translateExpression(call.args.single(), resultRegister)
+                code += VmCodeInstruction(Opcode.SWAP, VmDataType.BYTE, reg1 = resultRegister)
+                // note: if a word result is needed, the upper byte is cleared by the typecast that follows. No need to do it here.
+            }
+            "lsb" -> {
+                code += exprGen.translateExpression(call.args.single(), resultRegister)
+                // note: if a word result is needed, the upper byte is cleared by the typecast that follows. No need to do it here.
+            }
+            "memory" -> {
+                val name = (call.args[0] as PtString).value
+                val size = (call.args[1] as PtNumber).number.toUInt()
+                val align = (call.args[2] as PtNumber).number.toUInt()
+                val existing = codeGen.allocations.getMemorySlab(name)
+                val address = if(existing==null)
+                    codeGen.allocations.allocateMemorySlab(name, size, align)
+                else if(existing.second!=size || existing.third!=align) {
+                    codeGen.errors.err("memory slab '$name' already exists with a different size or alignment", call.position)
+                    return VmCodeChunk()
+                }
+                else
+                    existing.first
+                code += VmCodeInstruction(Opcode.LOAD, VmDataType.WORD, reg1=resultRegister, value=address.toInt())
+            }
+            "rnd" -> {
+                code += VmCodeInstruction(Opcode.SYSCALL, value= Syscall.RND.ordinal)
+                if(resultRegister!=0)
+                    code += VmCodeInstruction(Opcode.LOADR, VmDataType.BYTE, reg1=resultRegister, reg2=0)
+            }
+            "peek" -> {
+                val addressReg = codeGen.vmRegisters.nextFree()
+                code += exprGen.translateExpression(call.args.single(), addressReg)
+                code += VmCodeInstruction(Opcode.LOADI, VmDataType.BYTE, reg1 = resultRegister, reg2=addressReg)
+            }
+            "peekw" -> {
+                val addressReg = codeGen.vmRegisters.nextFree()
+                code += exprGen.translateExpression(call.args.single(), addressReg)
+                code += VmCodeInstruction(Opcode.LOADI, VmDataType.WORD, reg1 = resultRegister, reg2=addressReg)
+            }
+            "mkword" -> {
+                val msbReg = codeGen.vmRegisters.nextFree()
+                val lsbReg = codeGen.vmRegisters.nextFree()
+                code += exprGen.translateExpression(call.args[0], msbReg)
+                code += exprGen.translateExpression(call.args[1], lsbReg)
+                code += VmCodeInstruction(Opcode.CONCAT, VmDataType.BYTE, reg1=resultRegister, reg2=msbReg, reg3=lsbReg)
+            }
+            else -> {
+                TODO("builtinfunc ${call.name}")
+//                code += VmCodeInstruction(Opcode.NOP))
+//                for (arg in call.args) {
+//                    code += translateExpression(arg, resultRegister)
+//                    code += when(arg.type) {
+//                        in ByteDatatypes -> VmCodeInstruction(Opcode.PUSH, VmDataType.BYTE, reg1=resultRegister))
+//                        in WordDatatypes -> VmCodeInstruction(Opcode.PUSH, VmDataType.WORD, reg1=resultRegister))
+//                        else -> throw AssemblyError("weird arg dt")
+//                    }
+//                }
+//                code += VmCodeInstruction(Opcode.CALL), labelArg = listOf("_prog8_builtin", call.name))
+//                for (arg in call.args) {
+//                    code += when(arg.type) {
+//                        in ByteDatatypes -> VmCodeInstruction(Opcode.POP, VmDataType.BYTE, reg1=resultRegister))
+//                        in WordDatatypes -> VmCodeInstruction(Opcode.POP, VmDataType.WORD, reg1=resultRegister))
+//                        else -> throw AssemblyError("weird arg dt")
+//                    }
+//                }
+//                code += VmCodeInstruction(Opcode.NOP))
+            }
+        }
+        return code
+    }
+
+}

codeGenVirtual/src/prog8/codegen/virtual/CodeGen.kt

@@ -0,0 +1,593 @@
+package prog8.codegen.virtual
+
+import prog8.code.StStaticVariable
+import prog8.code.SymbolTable
+import prog8.code.ast.*
+import prog8.code.core.*
+import prog8.vm.Opcode
+import prog8.vm.VmDataType
+import kotlin.math.pow
+
+
+internal class VmRegisterPool {
+    private var firstFree: Int=3    // registers 0,1,2 are reserved
+    
+    fun peekNext() = firstFree
+
+    fun nextFree(): Int {
+        val result = firstFree
+        firstFree++
+        if(firstFree>65535)
+            throw AssemblyError("out of virtual registers")
+        return result
+    }
+}
+
+
+class CodeGen(internal val program: PtProgram,
+              internal val symbolTable: SymbolTable,
+              internal val options: CompilationOptions,
+              internal val errors: IErrorReporter
+): IAssemblyGenerator {
+
+    internal val allocations = VariableAllocator(symbolTable, program, errors)
+    private val expressionEval = ExpressionGen(this)
+    private val builtinFuncGen = BuiltinFuncGen(this, expressionEval)
+    internal val vmRegisters = VmRegisterPool()
+
+    init {
+        if(options.dontReinitGlobals)
+            TODO("support no globals re-init in vm")
+    }
+
+    override fun compileToAssembly(): IAssemblyProgram? {
+        val vmprog = AssemblyProgram(program.name, allocations)
+
+        // collect global variables initializers
+        program.allBlocks().forEach {
+            val code = VmCodeChunk()
+            it.children.filterIsInstance<PtAssignment>().forEach { assign -> code += translate(assign) }
+            vmprog.addGlobalInits(code)
+        }
+
+        for (block in program.allBlocks()) {
+            vmprog.addBlock(translate(block))
+        }
+
+        println("Vm codegen: amount of vm registers=${vmRegisters.peekNext()}")
+
+        return vmprog
+    }
+
+
+    private fun translateNode(node: PtNode): VmCodeChunk {
+        val code = when(node) {
+            is PtBlock -> translate(node)
+            is PtSub -> translate(node)
+            is PtScopeVarsDecls -> VmCodeChunk() // vars should be looked up via symbol table
+            is PtVariable -> VmCodeChunk() // var should be looked up via symbol table
+            is PtMemMapped -> VmCodeChunk() // memmapped var should be looked up via symbol table
+            is PtConstant -> VmCodeChunk() // constants have all been folded into the code
+            is PtAssignment -> translate(node)
+            is PtNodeGroup -> translateGroup(node.children)
+            is PtBuiltinFunctionCall -> translateBuiltinFunc(node, 0)
+            is PtFunctionCall -> expressionEval.translate(node, 0)
+            is PtNop -> VmCodeChunk()
+            is PtReturn -> translate(node)
+            is PtJump -> translate(node)
+            is PtWhen -> translate(node)
+            is PtPipe -> expressionEval.translate(node, 0)
+            is PtForLoop -> translate(node)
+            is PtIfElse -> translate(node)
+            is PtPostIncrDecr -> translate(node)
+            is PtRepeatLoop -> translate(node)
+            is PtLabel -> VmCodeChunk(VmCodeLabel(node.scopedName))
+            is PtBreakpoint -> VmCodeChunk(VmCodeInstruction(Opcode.BREAKPOINT))
+            is PtAddressOf,
+            is PtContainmentCheck,
+            is PtMemoryByte,
+            is PtProgram,
+            is PtArrayIndexer,
+            is PtBinaryExpression,
+            is PtIdentifier,
+            is PtWhenChoice,
+            is PtPrefix,
+            is PtRange,
+            is PtAssignTarget,
+            is PtTypeCast,
+            is PtSubroutineParameter,
+            is PtNumber,
+            is PtArray,
+            is PtString -> throw AssemblyError("strings should not occur as separate statement node ${node.position}")
+            is PtAsmSub -> throw AssemblyError("asmsub not supported on virtual machine target ${node.position}")
+            is PtInlineAssembly -> throw AssemblyError("inline assembly not supported on virtual machine target ${node.position}")
+            is PtIncludeBinary -> throw AssemblyError("inline binary data not supported on virtual machine target ${node.position}")
+            is PtConditionalBranch -> throw AssemblyError("conditional branches not supported in vm target due to lack of cpu flags ${node.position}")
+            else -> TODO("missing codegen for $node")
+        }
+        if(code.lines.isNotEmpty() && node.position.line!=0)
+            code.lines.add(0, VmCodeComment(node.position.toString()))
+        return code
+    }
+
+    private fun translate(whenStmt: PtWhen): VmCodeChunk {
+        if(whenStmt.choices.children.isEmpty())
+            return VmCodeChunk()
+        val code = VmCodeChunk()
+        val valueReg = vmRegisters.nextFree()
+        val choiceReg = vmRegisters.nextFree()
+        val valueDt = vmType(whenStmt.value.type)
+        code += expressionEval.translateExpression(whenStmt.value, valueReg)
+        val choices = whenStmt.choices.children.map {it as PtWhenChoice }
+        val endLabel = createLabelName()
+        for (choice in choices) {
+            if(choice.isElse) {
+                code += translateNode(choice.statements)
+            } else {
+                val skipLabel = createLabelName()
+                val values = choice.values.children.map {it as PtNumber}
+                if(values.size==1) {
+                    code += VmCodeInstruction(Opcode.LOAD, valueDt, reg1=choiceReg, value=values[0].number.toInt())
+                    code += VmCodeInstruction(Opcode.BNE, valueDt, reg1=valueReg, reg2=choiceReg, symbol = skipLabel)
+                    code += translateNode(choice.statements)
+                    if(choice.statements.children.last() !is PtReturn)
+                        code += VmCodeInstruction(Opcode.JUMP, symbol = endLabel)
+                } else {
+                    val matchLabel = createLabelName()
+                    for (value in values) {
+                        code += VmCodeInstruction(Opcode.LOAD, valueDt, reg1=choiceReg, value=value.number.toInt())
+                        code += VmCodeInstruction(Opcode.BEQ, valueDt, reg1=valueReg, reg2=choiceReg, symbol = matchLabel)
+                    }
+                    code += VmCodeInstruction(Opcode.JUMP, symbol = skipLabel)
+                    code += VmCodeLabel(matchLabel)
+                    code += translateNode(choice.statements)
+                    if(choice.statements.children.last() !is PtReturn)
+                        code += VmCodeInstruction(Opcode.JUMP, symbol = endLabel)
+                }
+                code += VmCodeLabel(skipLabel)
+            }
+        }
+        code += VmCodeLabel(endLabel)
+        return code
+    }
+
+    private fun translate(forLoop: PtForLoop): VmCodeChunk {
+        val loopvar = symbolTable.lookup(forLoop.variable.targetName) as StStaticVariable
+        val iterable = forLoop.iterable
+        val code = VmCodeChunk()
+        when(iterable) {
+            is PtRange -> {
+                if(iterable.from is PtNumber && iterable.to is PtNumber)
+                    code += translateForInConstantRange(forLoop, loopvar)
+                else
+                    code += translateForInNonConstantRange(forLoop, loopvar)
+            }
+            is PtIdentifier -> {
+                val arrayAddress = allocations.get(iterable.targetName)
+                val iterableVar = symbolTable.lookup(iterable.targetName) as StStaticVariable
+                val loopvarAddress = allocations.get(loopvar.scopedName)
+                val indexReg = vmRegisters.nextFree()
+                val loopLabel = createLabelName()
+                val endLabel = createLabelName()
+                if(iterableVar.dt==DataType.STR) {
+                    // iterate over a zero-terminated string
+                    code += VmCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=indexReg, value=0)
+                    code += VmCodeLabel(loopLabel)
+                    code += VmCodeInstruction(Opcode.LOADX, VmDataType.BYTE, reg1=0, reg2=indexReg, value = arrayAddress)
+                    code += VmCodeInstruction(Opcode.BZ, VmDataType.BYTE, reg1=0, symbol = endLabel)
+                    code += VmCodeInstruction(Opcode.STOREM, VmDataType.BYTE, reg1=0, value = loopvarAddress)
+                    code += translateNode(forLoop.statements)
+                    code += VmCodeInstruction(Opcode.INC, VmDataType.BYTE, reg1=indexReg)
+                    code += VmCodeInstruction(Opcode.JUMP, symbol = loopLabel)
+                    code += VmCodeLabel(endLabel)
+                } else {
+                    // iterate over array
+                    val elementDt = ArrayToElementTypes.getValue(iterable.type)
+                    val elementSize = program.memsizer.memorySize(elementDt)
+                    val lengthBytes = iterableVar.length!! * elementSize
+                    val lengthReg = vmRegisters.nextFree()
+                    code += VmCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=indexReg, value=0)
+                    code += VmCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=lengthReg, value=lengthBytes)
+                    code += VmCodeLabel(loopLabel)
+                    code += VmCodeInstruction(Opcode.BEQ, VmDataType.BYTE, reg1=indexReg, reg2=lengthReg, symbol = endLabel)
+                    code += VmCodeInstruction(Opcode.LOADX, vmType(elementDt), reg1=0, reg2=indexReg, value=arrayAddress)
+                    code += VmCodeInstruction(Opcode.STOREM, vmType(elementDt), reg1=0, value = loopvarAddress)
+                    code += translateNode(forLoop.statements)
+                    code += addConstReg(VmDataType.BYTE, indexReg, elementSize)
+                    code += VmCodeInstruction(Opcode.JUMP, symbol = loopLabel)
+                    code += VmCodeLabel(endLabel)
+                }
+            }
+            else -> throw AssemblyError("weird for iterable")
+        }
+        return code
+    }
+
+    private fun translateForInNonConstantRange(forLoop: PtForLoop, loopvar: StStaticVariable): VmCodeChunk {
+        val iterable = forLoop.iterable as PtRange
+        val step = iterable.step.number.toInt()
+        if (step==0)
+            throw AssemblyError("step 0")
+        val indexReg = vmRegisters.nextFree()
+        val endvalueReg = vmRegisters.nextFree()
+        val loopvarAddress = allocations.get(loopvar.scopedName)
+        val loopvarDt = vmType(loopvar.dt)
+        val loopLabel = createLabelName()
+        val code = VmCodeChunk()
+
+        code += expressionEval.translateExpression(iterable.to, endvalueReg)
+        code += expressionEval.translateExpression(iterable.from, indexReg)
+        code += VmCodeInstruction(Opcode.STOREM, loopvarDt, reg1=indexReg, value=loopvarAddress)
+        code += VmCodeLabel(loopLabel)
+        code += translateNode(forLoop.statements)
+        if(step<3) {
+            code += addConstMem(loopvarDt, loopvarAddress.toUInt(), step)
+            code += VmCodeInstruction(Opcode.LOADM, loopvarDt, reg1 = indexReg, value = loopvarAddress)
+        } else {
+            code += VmCodeInstruction(Opcode.LOADM, loopvarDt, reg1 = indexReg, value = loopvarAddress)
+            code += addConstReg(loopvarDt, indexReg, step)
+            code += VmCodeInstruction(Opcode.STOREM, loopvarDt, reg1 = indexReg, value = loopvarAddress)
+        }
+        val branchOpcode = if(loopvar.dt in SignedDatatypes) Opcode.BLES else Opcode.BLE
+        code += VmCodeInstruction(branchOpcode, loopvarDt, reg1=indexReg, reg2=endvalueReg, symbol=loopLabel)
+        return code
+    }
+
+    private fun translateForInConstantRange(forLoop: PtForLoop, loopvar: StStaticVariable): VmCodeChunk {
+        val iterable = forLoop.iterable as PtRange
+        val step = iterable.step.number.toInt()
+        val range = IntProgression.fromClosedRange(
+            (iterable.from as PtNumber).number.toInt(),
+            (iterable.to as PtNumber).number.toInt() + step,
+            step)
+        if (range.isEmpty() || range.step==0)
+            throw AssemblyError("empty range or step 0")
+
+        val loopLabel = createLabelName()
+        val loopvarAddress = allocations.get(loopvar.scopedName)
+        val indexReg = vmRegisters.nextFree()
+        val endvalueReg = vmRegisters.nextFree()
+        val loopvarDt = vmType(loopvar.dt)
+        val code = VmCodeChunk()
+        code += VmCodeInstruction(Opcode.LOAD, loopvarDt, reg1=endvalueReg, value=range.last)
+        code += VmCodeInstruction(Opcode.LOAD, loopvarDt, reg1=indexReg, value=range.first)
+        code += VmCodeInstruction(Opcode.STOREM, loopvarDt, reg1=indexReg, value=loopvarAddress)
+        code += VmCodeLabel(loopLabel)
+        code += translateNode(forLoop.statements)
+        if(range.step<3) {
+            code += addConstMem(loopvarDt, loopvarAddress.toUInt(), range.step)
+            code += VmCodeInstruction(Opcode.LOADM, loopvarDt, reg1 = indexReg, value = loopvarAddress)
+        } else {
+            code += VmCodeInstruction(Opcode.LOADM, loopvarDt, reg1 = indexReg, value = loopvarAddress)
+            code += addConstReg(loopvarDt, indexReg, range.step)
+            code += VmCodeInstruction(Opcode.STOREM, loopvarDt, reg1 = indexReg, value = loopvarAddress)
+        }
+        // TODO more optimal loop instruction for loops ending on 0 (BNZ?)
+        code += VmCodeInstruction(Opcode.BNE, loopvarDt, reg1=indexReg, reg2=endvalueReg, symbol=loopLabel)
+        return code
+    }
+
+    private fun addConstReg(dt: VmDataType, reg: Int, value: Int): VmCodeChunk {
+        val code = VmCodeChunk()
+        when(value) {
+            0 -> { /* do nothing */ }
+            1 -> {
+                code += VmCodeInstruction(Opcode.INC, dt, reg1=reg)
+            }
+            2 -> {
+                code += VmCodeInstruction(Opcode.INC, dt, reg1=reg)
+                code += VmCodeInstruction(Opcode.INC, dt, reg1=reg)
+            }
+            -1 -> {
+                code += VmCodeInstruction(Opcode.DEC, dt, reg1=reg)
+            }
+            -2 -> {
+                code += VmCodeInstruction(Opcode.DEC, dt, reg1=reg)
+                code += VmCodeInstruction(Opcode.DEC, dt, reg1=reg)
+            }
+            else -> {
+                val valueReg = vmRegisters.nextFree()
+                if(value>0) {
+                    code += VmCodeInstruction(Opcode.LOAD, dt, reg1=valueReg, value= value)
+                    code += VmCodeInstruction(Opcode.ADD, dt, reg1 = reg, reg2 = reg, reg3 = valueReg)
+                }
+                else {
+                    code += VmCodeInstruction(Opcode.LOAD, dt, reg1=valueReg, value= -value)
+                    code += VmCodeInstruction(Opcode.SUB, dt, reg1 = reg, reg2 = reg, reg3 = valueReg)
+                }
+            }
+        }
+        return code
+    }
+
+    private fun addConstMem(dt: VmDataType, address: UInt, value: Int): VmCodeChunk {
+        val code = VmCodeChunk()
+        when(value) {
+            0 -> { /* do nothing */ }
+            1 -> {
+                code += VmCodeInstruction(Opcode.INCM, dt, value=address.toInt())
+            }
+            2 -> {
+                code += VmCodeInstruction(Opcode.INCM, dt, value=address.toInt())
+                code += VmCodeInstruction(Opcode.INCM, dt, value=address.toInt())
+            }
+            -1 -> {
+                code += VmCodeInstruction(Opcode.DECM, dt, value=address.toInt())
+            }
+            -2 -> {
+                code += VmCodeInstruction(Opcode.DECM, dt, value=address.toInt())
+                code += VmCodeInstruction(Opcode.DECM, dt, value=address.toInt())
+            }
+            else -> {
+                val valueReg = vmRegisters.nextFree()
+                val operandReg = vmRegisters.nextFree()
+                if(value>0) {
+                    code += VmCodeInstruction(Opcode.LOADM, dt, reg1=valueReg, value=address.toInt())
+                    code += VmCodeInstruction(Opcode.LOAD, dt, reg1=operandReg, value=value)
+                    code += VmCodeInstruction(Opcode.ADD, dt, reg1 = valueReg, reg2 = valueReg, reg3 = operandReg)
+                    code += VmCodeInstruction(Opcode.STOREM, dt, reg1=valueReg, value=address.toInt())
+                }
+                else {
+                    code += VmCodeInstruction(Opcode.LOADM, dt, reg1=valueReg, value=address.toInt())
+                    code += VmCodeInstruction(Opcode.LOAD, dt, reg1=operandReg, value=-value)
+                    code += VmCodeInstruction(Opcode.SUB, dt, reg1 = valueReg, reg2 = valueReg, reg3 = operandReg)
+                    code += VmCodeInstruction(Opcode.STOREM, dt, reg1=valueReg, value=address.toInt())
+                }
+            }
+        }
+        return code
+    }
+
+    private val powersOfTwo = (0..16).map { 2.0.pow(it.toDouble()).toInt() }
+
+    private fun multiplyByConst(dt: VmDataType, reg: Int, factor: UInt): VmCodeChunk {
+        val code = VmCodeChunk()
+        val pow2 = powersOfTwo.indexOf(factor.toInt())
+        if(pow2>=1) {
+            // just shift bits
+            code += VmCodeInstruction(Opcode.LSL, dt, reg1=reg, reg2=reg, reg3=pow2)
+        } else {
+            when(factor) {
+                0u -> {
+                    code += VmCodeInstruction(Opcode.LOAD, dt, reg1=reg, value=0)
+                }
+                1u -> { /* do nothing */ }
+                else -> {
+                    val factorReg = vmRegisters.nextFree()
+                    code += VmCodeInstruction(Opcode.LOAD, dt, reg1=factorReg, value=factor.toInt())
+                    code += VmCodeInstruction(Opcode.MUL, dt, reg1=reg, reg2=reg, reg3=factorReg)
+                }
+            }
+        }
+        return code
+    }
+
+    private fun translate(ifElse: PtIfElse): VmCodeChunk {
+        var branch = Opcode.BZ
+        var condition = ifElse.condition
+
+        val cond = ifElse.condition as? PtBinaryExpression
+        if((cond?.right as? PtNumber)?.number==0.0) {
+            if(cond.operator == "==") {
+                // if X==0 ...   so we branch on Not-zero instead.
+                branch = Opcode.BNZ
+                condition = cond.left
+            }
+            else if(cond.operator == "!=") {
+                // if X!=0 ...   so we keep branching on Zero.
+                condition = cond.left
+            }
+        }
+
+        val conditionReg = vmRegisters.nextFree()
+        val vmDt = vmType(condition.type)
+        val code = VmCodeChunk()
+        code += expressionEval.translateExpression(condition, conditionReg)
+        if(ifElse.elseScope.children.isNotEmpty()) {
+            // if and else parts
+            val elseLabel = createLabelName()
+            val afterIfLabel = createLabelName()
+            code += VmCodeInstruction(branch, vmDt, reg1=conditionReg, symbol = elseLabel)
+            code += translateNode(ifElse.ifScope)
+            code += VmCodeInstruction(Opcode.JUMP, symbol = afterIfLabel)
+            code += VmCodeLabel(elseLabel)
+            code += translateNode(ifElse.elseScope)
+            code += VmCodeLabel(afterIfLabel)
+        } else {
+            // only if part
+            val afterIfLabel = createLabelName()
+            code += VmCodeInstruction(branch, vmDt, reg1=conditionReg, symbol = afterIfLabel)
+            code += translateNode(ifElse.ifScope)
+            code += VmCodeLabel(afterIfLabel)
+        }
+        return code
+    }
+
+    private fun translate(postIncrDecr: PtPostIncrDecr): VmCodeChunk {
+        val code = VmCodeChunk()
+        val operation = when(postIncrDecr.operator) {
+            "++" -> Opcode.INC
+            "--" -> Opcode.DEC
+            else -> throw AssemblyError("weird operator")
+        }
+        val ident = postIncrDecr.target.identifier
+        val memory = postIncrDecr.target.memory
+        val array = postIncrDecr.target.array
+        val vmDt = vmType(postIncrDecr.target.type)
+        val resultReg = vmRegisters.nextFree()
+        if(ident!=null) {
+            val address = allocations.get(ident.targetName)
+            code += VmCodeInstruction(Opcode.LOADM, vmDt, reg1=resultReg, value = address)
+            code += VmCodeInstruction(operation, vmDt, reg1=resultReg)
+            code += VmCodeInstruction(Opcode.STOREM, vmDt, reg1=resultReg, value = address)
+        } else if(memory!=null) {
+            val addressReg = vmRegisters.nextFree()
+            code += expressionEval.translateExpression(memory.address, addressReg)
+            code += VmCodeInstruction(Opcode.LOADI, vmDt, reg1=resultReg, reg2=addressReg)
+            code += VmCodeInstruction(operation, vmDt, reg1=resultReg)
+            code += VmCodeInstruction(Opcode.STOREI, vmDt, reg1=resultReg, reg2=addressReg)
+        } else if (array!=null) {
+            val variable = array.variable.targetName
+            var variableAddr = allocations.get(variable)
+            val itemsize = program.memsizer.memorySize(array.type)
+            val fixedIndex = (array.index as? PtNumber)?.number?.toInt()
+            val memOp = when(postIncrDecr.operator) {
+                "++" -> Opcode.INCM
+                "--" -> Opcode.DECM
+                else -> throw AssemblyError("weird operator")
+            }
+            if(fixedIndex!=null) {
+                variableAddr += fixedIndex*itemsize
+                code += VmCodeInstruction(memOp, vmDt, value=variableAddr)
+            } else {
+                val indexReg = vmRegisters.nextFree()
+                code += expressionEval.translateExpression(array.index, indexReg)
+                code += VmCodeInstruction(Opcode.LOADX, vmDt, reg1=resultReg, reg2=indexReg, value=variableAddr)
+                code += VmCodeInstruction(operation, vmDt, reg1=resultReg)
+                code += VmCodeInstruction(Opcode.STOREX, vmDt, reg1=resultReg, reg2=indexReg, value=variableAddr)
+            }
+        } else
+            throw AssemblyError("weird assigntarget")
+
+        return code
+    }
+
+    private fun translate(repeat: PtRepeatLoop): VmCodeChunk {
+        if((repeat.count as? PtNumber)?.number==0.0)
+            return VmCodeChunk()
+        if((repeat.count as? PtNumber)?.number==1.0)
+            return translateGroup(repeat.children)
+        if((repeat.count as? PtNumber)?.number==256.0) {
+            // 256 iterations can still be done with just a byte counter if you set it to zero as starting value.
+            repeat.children[0] = PtNumber(DataType.UBYTE, 0.0, repeat.count.position)
+        }
+
+        val code = VmCodeChunk()
+        val counterReg = vmRegisters.nextFree()
+        val vmDt = vmType(repeat.count.type)
+        code += expressionEval.translateExpression(repeat.count, counterReg)
+        val repeatLabel = createLabelName()
+        code += VmCodeLabel(repeatLabel)
+        code += translateNode(repeat.statements)
+        code += VmCodeInstruction(Opcode.DEC, vmDt, reg1=counterReg)
+        code += VmCodeInstruction(Opcode.BNZ, vmDt, reg1=counterReg, symbol = repeatLabel)
+        return code
+    }
+
+    private fun translate(jump: PtJump): VmCodeChunk {
+        val code = VmCodeChunk()
+        if(jump.address!=null)
+            throw AssemblyError("cannot jump to memory location in the vm target")
+        code += if(jump.generatedLabel!=null)
+            VmCodeInstruction(Opcode.JUMP, symbol = listOf(jump.generatedLabel!!))
+        else if(jump.identifier!=null)
+            VmCodeInstruction(Opcode.JUMP, symbol = jump.identifier!!.targetName)
+        else
+            throw AssemblyError("weird jump")
+        return code
+    }
+
+    private fun translateGroup(group: List<PtNode>): VmCodeChunk {
+        val code = VmCodeChunk()
+        group.forEach { code += translateNode(it) }
+        return code
+    }
+
+    private fun translate(assignment: PtAssignment): VmCodeChunk {
+        // TODO can in-place assignments (assignment.augmentable = true) be optimized more?
+
+        val code = VmCodeChunk()
+        val resultRegister = vmRegisters.nextFree()
+        code += expressionEval.translateExpression(assignment.value, resultRegister)
+        val ident = assignment.target.identifier
+        val memory = assignment.target.memory
+        val array = assignment.target.array
+        val vmDt = vmType(assignment.value.type)
+        if(ident!=null) {
+            val address = allocations.get(ident.targetName)
+            code += VmCodeInstruction(Opcode.STOREM, vmDt, reg1=resultRegister, value=address)
+        }
+        else if(array!=null) {
+            val variable = array.variable.targetName
+            var variableAddr = allocations.get(variable)
+            val itemsize = program.memsizer.memorySize(array.type)
+            val fixedIndex = (array.index as? PtNumber)?.number?.toInt()
+            val vmDtArrayIdx = vmType(array.type)
+            if(fixedIndex!=null) {
+                variableAddr += fixedIndex*itemsize
+                code += VmCodeInstruction(Opcode.STOREM, vmDtArrayIdx, reg1 = resultRegister, value=variableAddr)
+            } else {
+                val indexReg = vmRegisters.nextFree()
+                code += expressionEval.translateExpression(array.index, indexReg)
+                code += VmCodeInstruction(Opcode.STOREX, vmDtArrayIdx, reg1 = resultRegister, reg2=indexReg, value=variableAddr)
+            }
+        }
+        else if(memory!=null) {
+            if(memory.address is PtNumber) {
+                code += VmCodeInstruction(Opcode.STOREM, vmDt, reg1=resultRegister, value=(memory.address as PtNumber).number.toInt())
+            } else {
+                val addressRegister = vmRegisters.nextFree()
+                code += expressionEval.translateExpression(assignment.value, addressRegister)
+                code += VmCodeInstruction(Opcode.STOREI, vmDt, reg1=resultRegister, reg2=addressRegister)
+            }
+        }
+        else
+            throw AssemblyError("weird assigntarget")
+        return code
+    }
+
+    private fun translate(ret: PtReturn): VmCodeChunk {
+        val code = VmCodeChunk()
+        val value = ret.value
+        if(value!=null) {
+            // Call Convention: return value is always returned in r0
+            code += expressionEval.translateExpression(value, 0)
+        }
+        code += VmCodeInstruction(Opcode.RETURN)
+        return code
+    }
+
+    private fun translate(sub: PtSub): VmCodeChunk {
+        // TODO actually inline subroutines marked as inline
+        val code = VmCodeChunk()
+        code += VmCodeComment("SUB: ${sub.scopedName} -> ${sub.returntype}")
+        code += VmCodeLabel(sub.scopedName)
+        for (child in sub.children) {
+            code += translateNode(child)
+        }
+        code += VmCodeComment("SUB-END '${sub.name}'")
+        return code
+    }
+
+    private fun translate(block: PtBlock): VmCodeChunk {
+        val code = VmCodeChunk()
+        code += VmCodeComment("BLOCK '${block.name}'  addr=${block.address}  lib=${block.library}")
+        for (child in block.children) {
+            if(child !is PtAssignment) // global variable initialization is done elsewhere
+                code += translateNode(child)
+        }
+        code += VmCodeComment("BLOCK-END '${block.name}'")
+        return code
+    }
+
+
+    internal fun vmType(type: DataType): VmDataType {
+        return when(type) {
+            DataType.UBYTE,
+            DataType.BYTE -> VmDataType.BYTE
+            DataType.UWORD,
+            DataType.WORD -> VmDataType.WORD
+            in PassByReferenceDatatypes -> VmDataType.WORD
+            else -> throw AssemblyError("no vm datatype for $type")
+        }
+    }
+
+    private var labelSequenceNumber = 0
+    internal fun createLabelName(): List<String> {
+        labelSequenceNumber++
+        return listOf("prog8_label_gen_$labelSequenceNumber")
+    }
+
+    internal fun translateBuiltinFunc(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk =
+        builtinFuncGen.translate(call, resultRegister)
+}

codeGenVirtual/src/prog8/codegen/virtual/ExpressionGen.kt

@@ -0,0 +1,306 @@
+package prog8.codegen.virtual
+
+import prog8.code.StStaticVariable
+import prog8.code.StSub
+import prog8.code.ast.*
+import prog8.code.core.AssemblyError
+import prog8.code.core.DataType
+import prog8.code.core.PassByValueDatatypes
+import prog8.code.core.SignedDatatypes
+import prog8.vm.Opcode
+import prog8.vm.VmDataType
+
+
+internal class ExpressionGen(private val codeGen: CodeGen) {
+    fun translateExpression(expr: PtExpression, resultRegister: Int): VmCodeChunk {
+        require(codeGen.vmRegisters.peekNext() > resultRegister)
+
+        val code = VmCodeChunk()
+        val vmDt = codeGen.vmType(expr.type)
+
+        when (expr) {
+            is PtNumber -> {
+                code += VmCodeInstruction(Opcode.LOAD, vmDt, reg1=resultRegister, value=expr.number.toInt())
+            }
+            is PtIdentifier -> {
+                val mem = codeGen.allocations.get(expr.targetName)
+                code += if(expr.type in PassByValueDatatypes) {
+                    VmCodeInstruction(Opcode.LOADM, vmDt, reg1=resultRegister, value=mem)
+                } else {
+                    // for strings and arrays etc., load the *address* of the value instead
+                    VmCodeInstruction(Opcode.LOAD, vmDt, reg1=resultRegister, value=mem)
+                }
+            }
+            is PtAddressOf -> {
+                val mem = codeGen.allocations.get(expr.identifier.targetName)
+                code += VmCodeInstruction(Opcode.LOAD, vmDt, reg1=resultRegister, value=mem)
+            }
+            is PtMemoryByte -> {
+                val addressRegister = codeGen.vmRegisters.nextFree()
+                val addressExprCode = translateExpression(expr.address, addressRegister)
+                code += addressExprCode
+            }
+            is PtTypeCast -> code += translate(expr, resultRegister)
+            is PtPrefix -> code += translate(expr, resultRegister)
+            is PtArrayIndexer -> code += translate(expr, resultRegister)
+            is PtBinaryExpression -> code += translate(expr, resultRegister)
+            is PtBuiltinFunctionCall -> code += codeGen.translateBuiltinFunc(expr, resultRegister)
+            is PtFunctionCall -> code += translate(expr, resultRegister)
+            is PtContainmentCheck -> code += translate(expr, resultRegister)
+            is PtPipe -> code += translate(expr, resultRegister)
+            is PtRange,
+            is PtArray,
+            is PtString -> throw AssemblyError("range/arrayliteral/string should no longer occur as expression")
+            else -> throw AssemblyError("weird expression")
+        }
+        return code
+    }
+
+    internal fun translate(pipe: PtPipe, resultRegister: Int): VmCodeChunk {
+        TODO("Not yet implemented: pipe expression")
+    }
+
+    private fun translate(check: PtContainmentCheck, resultRegister: Int): VmCodeChunk {
+        val code = VmCodeChunk()
+        code += translateExpression(check.element, resultRegister)   // load the element to check in resultRegister
+        val iterable = codeGen.symbolTable.flat.getValue(check.iterable.targetName) as StStaticVariable
+        when(iterable.dt) {
+            DataType.STR -> {
+                val call = PtFunctionCall(listOf("prog8_lib", "string_contains"), false, DataType.UBYTE, check.position)
+                call.children.add(check.element)
+                call.children.add(check.iterable)
+                code += translate(call, resultRegister)
+            }
+            DataType.ARRAY_UB, DataType.ARRAY_B -> {
+                val call = PtFunctionCall(listOf("prog8_lib", "bytearray_contains"), false, DataType.UBYTE, check.position)
+                call.children.add(check.element)
+                call.children.add(check.iterable)
+                call.children.add(PtNumber(DataType.UBYTE, iterable.length!!.toDouble(), iterable.position))
+                code += translate(call, resultRegister)
+            }
+            DataType.ARRAY_UW, DataType.ARRAY_W -> {
+                val call = PtFunctionCall(listOf("prog8_lib", "wordarray_contains"), false, DataType.UBYTE, check.position)
+                call.children.add(check.element)
+                call.children.add(check.iterable)
+                call.children.add(PtNumber(DataType.UBYTE, iterable.length!!.toDouble(), iterable.position))
+                code += translate(call, resultRegister)
+            }
+            DataType.ARRAY_F -> TODO("containment check in float-array")
+            else -> throw AssemblyError("weird iterable dt ${iterable.dt} for ${check.iterable.targetName}")
+        }
+        return code
+    }
+
+    private fun translate(arrayIx: PtArrayIndexer, resultRegister: Int): VmCodeChunk {
+        val eltSize = codeGen.program.memsizer.memorySize(arrayIx.type)
+        val vmDt = codeGen.vmType(arrayIx.type)
+        val code = VmCodeChunk()
+        val idxReg = codeGen.vmRegisters.nextFree()
+        // TODO: optimized code when the index is a constant value
+        code += translateExpression(arrayIx.index, idxReg)
+        if(eltSize>1) {
+            val factorReg = codeGen.vmRegisters.nextFree()
+            code += VmCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=factorReg, value=eltSize)
+            code += VmCodeInstruction(Opcode.MUL, VmDataType.BYTE, reg1=idxReg, reg2=idxReg, reg3=factorReg)
+        }
+        val arrayLocation = codeGen.allocations.get(arrayIx.variable.targetName)
+        code += VmCodeInstruction(Opcode.LOADX, vmDt, reg1=resultRegister, reg2=idxReg, value = arrayLocation)
+        return code
+    }
+
+    private fun translate(expr: PtPrefix, resultRegister: Int): VmCodeChunk {
+        val code = VmCodeChunk()
+        code += translateExpression(expr.value, resultRegister)
+        val vmDt = codeGen.vmType(expr.type)
+        when(expr.operator) {
+            "+" -> { }
+            "-" -> {
+                code += VmCodeInstruction(Opcode.NEG, vmDt, reg1=resultRegister)
+            }
+            "~" -> {
+                val regMask = codeGen.vmRegisters.nextFree()
+                val mask = if(vmDt==VmDataType.BYTE) 0x00ff else 0xffff
+                code += VmCodeInstruction(Opcode.LOAD, vmDt, reg1=regMask, value=mask)
+                code += VmCodeInstruction(Opcode.XOR, vmDt, reg1=resultRegister, reg2=resultRegister, reg3=regMask)
+            }
+            "not" -> {
+                val label = codeGen.createLabelName()
+                code += VmCodeInstruction(Opcode.BZ, vmDt, reg1=resultRegister, symbol = label)
+                code += VmCodeInstruction(Opcode.LOAD, vmDt, reg1=resultRegister, value=1)
+                code += VmCodeLabel(label)
+                val regMask = codeGen.vmRegisters.nextFree()
+                code += VmCodeInstruction(Opcode.LOAD, vmDt, reg1=regMask, value=1)
+                code += VmCodeInstruction(Opcode.XOR, vmDt, reg1=resultRegister, reg2=resultRegister, reg3=regMask)
+            }
+            else -> throw AssemblyError("weird prefix operator")
+        }
+        return code
+    }
+
+    private fun translate(cast: PtTypeCast, resultRegister: Int): VmCodeChunk {
+        val code = VmCodeChunk()
+        if(cast.type==cast.value.type)
+            return code
+        code += translateExpression(cast.value, resultRegister)
+        when(cast.type) {
+            DataType.UBYTE -> {
+                when(cast.value.type) {
+                    DataType.BYTE, DataType.UWORD, DataType.WORD -> { /* just keep the LSB as it is */ }
+                    DataType.FLOAT -> {
+                        TODO("float -> ubyte") // float not yet supported
+                    }
+                    else -> throw AssemblyError("weird cast value type")
+                }
+            }
+            DataType.BYTE -> {
+                when(cast.value.type) {
+                    DataType.UBYTE, DataType.UWORD, DataType.WORD -> { /* just keep the LSB as it is */ }
+                    DataType.FLOAT -> {
+                        TODO("float -> byte") // float not yet supported
+                    }
+                    else -> throw AssemblyError("weird cast value type")
+                }
+            }
+            DataType.UWORD -> {
+                when(cast.value.type) {
+                    DataType.BYTE -> {
+                        // byte -> uword:   sign extend
+                        code += VmCodeInstruction(Opcode.EXTS, type = VmDataType.BYTE, reg1 = resultRegister)
+                    }
+                    DataType.UBYTE -> {
+                        // ubyte -> uword:   sign extend
+                        code += VmCodeInstruction(Opcode.EXT, type = VmDataType.BYTE, reg1 = resultRegister)
+                    }
+                    DataType.WORD -> { }
+                    DataType.FLOAT -> {
+                        TODO("float -> uword") // float not yet supported
+                    }
+                    else -> throw AssemblyError("weird cast value type")
+                }
+            }
+            DataType.WORD -> {
+                when(cast.value.type) {
+                    DataType.BYTE -> {
+                        // byte -> word:   sign extend
+                        code += VmCodeInstruction(Opcode.EXTS, type = VmDataType.BYTE, reg1 = resultRegister)
+                    }
+                    DataType.UBYTE -> {
+                        // byte -> word:   sign extend
+                        code += VmCodeInstruction(Opcode.EXT, type = VmDataType.BYTE, reg1 = resultRegister)
+                    }
+                    DataType.UWORD -> { }
+                    DataType.FLOAT -> {
+                        TODO("float -> word") // float not yet supported
+                    }
+                    else -> throw AssemblyError("weird cast value type")
+                }
+            }
+            DataType.FLOAT -> {
+                TODO("floating point not yet supported")
+//                when(cast.value.type) {
+//                    DataType.BYTE -> {
+//                    }
+//                    DataType.UBYTE -> {
+//                    }
+//                    DataType.WORD -> {
+//                    }
+//                    DataType.UWORD -> {
+//                    }
+//                    else -> throw AssemblyError("weird cast value type")
+//                }
+            }
+            else -> throw AssemblyError("weird cast type")
+        }
+        return code
+    }
+
+    private fun translate(binExpr: PtBinaryExpression, resultRegister: Int): VmCodeChunk {
+        val code = VmCodeChunk()
+        val leftResultReg = codeGen.vmRegisters.nextFree()
+        val rightResultReg = codeGen.vmRegisters.nextFree()
+        // TODO: optimized codegen when left or right operand is known 0 or 1 or whatever. But only if this would result in a different opcode such as ADD 1 -> INC, MUL 1 -> NOP
+        //       actually optimizing the code should not be done here but in a tailored code optimizer step.
+        val leftCode = translateExpression(binExpr.left, leftResultReg)
+        val rightCode = translateExpression(binExpr.right, rightResultReg)
+        code += leftCode
+        code += rightCode
+        val vmDt = codeGen.vmType(binExpr.left.type)
+        val signed = binExpr.left.type in SignedDatatypes
+        when(binExpr.operator) {
+            "+" -> {
+                code += VmCodeInstruction(Opcode.ADD, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            "-" -> {
+                code += VmCodeInstruction(Opcode.SUB, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            "*" -> {
+                code += VmCodeInstruction(Opcode.MUL, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            "/" -> {
+                code += VmCodeInstruction(Opcode.DIV, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            "%" -> {
+                code += VmCodeInstruction(Opcode.MOD, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            "|", "or" -> {
+                code += VmCodeInstruction(Opcode.OR, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            "&", "and" -> {
+                code += VmCodeInstruction(Opcode.AND, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            "^", "xor" -> {
+                code += VmCodeInstruction(Opcode.XOR, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            "<<" -> {
+                code += VmCodeInstruction(Opcode.LSL, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            ">>" -> {
+                val opc = if(signed) Opcode.ASR else Opcode.LSR
+                code += VmCodeInstruction(opc, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            "==" -> {
+                code += VmCodeInstruction(Opcode.SEQ, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            "!=" -> {
+                code += VmCodeInstruction(Opcode.SNE, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            "<" -> {
+                val ins = if(signed) Opcode.SLTS else Opcode.SLT
+                code += VmCodeInstruction(ins, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            ">" -> {
+                val ins = if(signed) Opcode.SGTS else Opcode.SGT
+                code += VmCodeInstruction(ins, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            "<=" -> {
+                val ins = if(signed) Opcode.SLES else Opcode.SLE
+                code += VmCodeInstruction(ins, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            ">=" -> {
+                val ins = if(signed) Opcode.SGES else Opcode.SGE
+                code += VmCodeInstruction(ins, vmDt, reg1=resultRegister, reg2=leftResultReg, reg3=rightResultReg)
+            }
+            else -> throw AssemblyError("weird operator ${binExpr.operator}")
+        }
+        return code
+    }
+
+    fun translate(fcall: PtFunctionCall, resultRegister: Int): VmCodeChunk {
+        val subroutine = codeGen.symbolTable.flat.getValue(fcall.functionName) as StSub
+        val code = VmCodeChunk()
+        for ((arg, parameter) in fcall.args.zip(subroutine.parameters)) {
+            val argReg = codeGen.vmRegisters.nextFree()
+            code += translateExpression(arg, argReg)
+            val vmDt = codeGen.vmType(parameter.type)
+            val mem = codeGen.allocations.get(fcall.functionName + parameter.name)
+            code += VmCodeInstruction(Opcode.STOREM, vmDt, reg1=argReg, value=mem)
+        }
+        code += VmCodeInstruction(Opcode.CALL, symbol=fcall.functionName)
+        if(!fcall.void && resultRegister!=0) {
+            // Call convention: result value is in r0, so put it in the required register instead.
+            code += VmCodeInstruction(Opcode.LOADR, codeGen.vmType(fcall.type), reg1=resultRegister, reg2=0)
+        }
+        return code
+    }
+
+}

codeGenVirtual/src/prog8/codegen/virtual/VariableAllocator.kt

@@ -0,0 +1,91 @@
+package prog8.codegen.virtual
+
+import prog8.code.SymbolTable
+import prog8.code.ast.PtProgram
+import prog8.code.core.*
+
+class VariableAllocator(private val st: SymbolTable, private val program: PtProgram, errors: IErrorReporter) {
+
+    private val allocations = mutableMapOf<List<String>, Int>()
+    private var freeMemoryStart: Int
+
+    val freeMem: Int
+        get() = freeMemoryStart
+
+    init {
+        var nextLocation = 0
+        for (variable in st.allVariables) {
+            val memsize =
+                when (variable.dt) {
+                    DataType.STR -> variable.initialStringValue!!.first.length + 1  // include the zero byte
+                    in NumericDatatypes -> program.memsizer.memorySize(variable.dt)
+                    in ArrayDatatypes -> program.memsizer.memorySize(variable.dt, variable.length!!)
+                    else -> throw InternalCompilerException("weird dt")
+                }
+
+            allocations[variable.scopedName] = nextLocation
+            nextLocation += memsize
+        }
+
+        freeMemoryStart = nextLocation
+    }
+
+    fun get(name: List<String>) = allocations.getValue(name)
+
+    fun asVmMemory(): List<Pair<List<String>, String>> {
+        val mm = mutableListOf<Pair<List<String>, String>>()
+        for (variable in st.allVariables) {
+            val location = allocations.getValue(variable.scopedName)
+            val typeStr = when(variable.dt) {
+                DataType.UBYTE, DataType.ARRAY_UB, DataType.STR -> "ubyte"
+                DataType.BYTE, DataType.ARRAY_B -> "byte"
+                DataType.UWORD, DataType.ARRAY_UW -> "uword"
+                DataType.WORD, DataType.ARRAY_W -> "word"
+                DataType.FLOAT, DataType.ARRAY_F -> "float"
+                else -> throw InternalCompilerException("weird dt")
+            }
+            val value = when(variable.dt) {
+                DataType.FLOAT -> (variable.initialNumericValue ?: 0.0).toString()
+                in NumericDatatypes -> (variable.initialNumericValue ?: 0).toHex()
+                DataType.STR -> {
+                    val encoded = program.encoding.encodeString(variable.initialStringValue!!.first, variable.initialStringValue!!.second)
+                    encoded.joinToString(",") { it.toInt().toHex() } + ",0"
+                }
+                DataType.ARRAY_F -> {
+                    if(variable.initialArrayValue!=null) {
+                        variable.initialArrayValue!!.joinToString(",") { it.number!!.toString() }
+                    } else {
+                        (1..variable.length!!).joinToString(",") { "0" }
+                    }
+                }
+                in ArrayDatatypes -> {
+                    if(variable.initialArrayValue!==null) {
+                        variable.initialArrayValue!!.joinToString(",") { it.number!!.toHex() }
+                    } else {
+                        (1..variable.length!!).joinToString(",") { "0" }
+                    }
+                }
+                else -> throw InternalCompilerException("weird dt")
+            }
+            mm.add(Pair(variable.scopedName, "${location.toHex()} $typeStr $value"))
+        }
+        return mm
+    }
+
+    private val memorySlabsInternal = mutableMapOf<String, Triple<UInt, UInt, UInt>>()
+    internal val memorySlabs: Map<String, Triple<UInt, UInt, UInt>> = memorySlabsInternal
+
+    fun allocateMemorySlab(name: String, size: UInt, align: UInt): UInt {
+        val address =
+            if(align==0u || align==1u)
+                freeMemoryStart.toUInt()
+            else
+                (freeMemoryStart.toUInt() + align-1u) and (0xffffffffu xor (align-1u))
+
+        memorySlabsInternal[name] = Triple(address, size, align)
+        freeMemoryStart = (address + size).toInt()
+        return address
+    }
+
+    fun getMemorySlab(name: String): Triple<UInt, UInt, UInt>? = memorySlabsInternal[name]
+}

codeGeneration/src/prog8/compiler/target/AssemblyError.kt

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

codeGeneration/src/prog8/compiler/target/C64Target.kt

@@ -1,35 +0,0 @@
-package prog8.compiler.target
-
-import com.github.michaelbull.result.fold
-import prog8.ast.base.ByteDatatypes
-import prog8.ast.base.DataType
-import prog8.ast.base.PassByReferenceDatatypes
-import prog8.ast.base.WordDatatypes
-import prog8.compiler.target.c64.C64MachineDefinition
-import prog8.compiler.target.cbm.Petscii
-import prog8.compilerinterface.ICompilationTarget
-
-
-object C64Target: ICompilationTarget {
-    override val name = "c64"
-    override val machine = C64MachineDefinition
-    override fun encodeString(str: String, altEncoding: Boolean): List<Short> {
-        val coded = if (altEncoding) Petscii.encodeScreencode(str, true) else Petscii.encodePetscii(str, true)
-        return coded.fold(
-            failure = { throw it },
-            success = { it }
-        )
-    }
-    override fun decodeString(bytes: List<Short>, altEncoding: Boolean) =
-        if (altEncoding) Petscii.decodeScreencode(bytes, true) else Petscii.decodePetscii(bytes, true)
-
-    override fun memorySize(dt: DataType): Int {
-        return when(dt) {
-            in ByteDatatypes -> 1
-            in WordDatatypes -> 2
-            DataType.FLOAT -> machine.FLOAT_MEM_SIZE
-            in PassByReferenceDatatypes -> machine.POINTER_MEM_SIZE
-            else -> -9999999
-        }
-    }
-}

codeGeneration/src/prog8/compiler/target/Cx16Target.kt

@@ -1,36 +0,0 @@
-package prog8.compiler.target
-
-import com.github.michaelbull.result.fold
-import prog8.ast.base.ByteDatatypes
-import prog8.ast.base.DataType
-import prog8.ast.base.PassByReferenceDatatypes
-import prog8.ast.base.WordDatatypes
-import prog8.compiler.target.cbm.Petscii
-import prog8.compiler.target.cx16.CX16MachineDefinition
-import prog8.compilerinterface.ICompilationTarget
-
-
-object Cx16Target: ICompilationTarget {
-    override val name = "cx16"
-    override val machine = CX16MachineDefinition
-    override fun encodeString(str: String, altEncoding: Boolean): List<Short> {
-        val coded= if (altEncoding) Petscii.encodeScreencode(str, true) else Petscii.encodePetscii(str, true)
-        return coded.fold(
-            failure = { throw it },
-            success = { it }
-        )
-    }
-    override fun decodeString(bytes: List<Short>, altEncoding: Boolean) =
-        if (altEncoding) Petscii.decodeScreencode(bytes, true) else Petscii.decodePetscii(bytes, true)
-
-    override fun memorySize(dt: DataType): Int {
-        return when(dt) {
-            in ByteDatatypes -> 1
-            in WordDatatypes -> 2
-            DataType.FLOAT -> machine.FLOAT_MEM_SIZE
-            in PassByReferenceDatatypes -> machine.POINTER_MEM_SIZE
-            else -> -9999999
-        }
-    }
-}
-

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

@@ -1,206 +0,0 @@
-package prog8.compiler.target.c64
-
-import prog8.compiler.target.cbm.viceMonListPostfix
-import prog8.compilerinterface.*
-import java.io.IOException
-import java.nio.file.Path
-import kotlin.math.absoluteValue
-import kotlin.math.pow
-
-object C64MachineDefinition: IMachineDefinition {
-
-    override val cpu = CpuType.CPU6502
-
-    // 5-byte cbm MFLPT format limitations:
-    override val FLOAT_MAX_POSITIVE = 1.7014118345e+38         // bytes: 255,127,255,255,255
-    override val FLOAT_MAX_NEGATIVE = -1.7014118345e+38        // bytes: 255,255,255,255,255
-    override val FLOAT_MEM_SIZE = 5
-    override val POINTER_MEM_SIZE = 2
-    override val BASIC_LOAD_ADDRESS = 0x0801
-    override val RAW_LOAD_ADDRESS = 0xc000
-
-    // the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
-    override val ESTACK_LO = 0xce00        //  $ce00-$ceff inclusive
-    override val ESTACK_HI = 0xcf00        //  $ce00-$ceff inclusive
-
-    override lateinit var zeropage: Zeropage
-
-    override fun getFloat(num: Number) = Mflpt5.fromNumber(num)
-
-    override fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
-        return if (compilerOptions.launcher == LauncherType.BASIC || compilerOptions.output == OutputType.PRG)
-            listOf("syslib")
-        else
-            emptyList()
-    }
-
-    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 $emulator...")
-            val cmdline = listOf(emulator, "-silent", "-moncommands", "${programNameWithPath}.$viceMonListPostfix",
-                    "-autostartprgmode", "1", "-autostart-warp", "-autostart", "${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 isRegularRAMaddress(address: Int): Boolean = address<0xa000 || address in 0xc000..0xcfff
-
-    override fun initializeZeropage(compilerOptions: CompilationOptions) {
-        zeropage = C64Zeropage(compilerOptions)
-    }
-
-    // 6502 opcodes (including aliases and illegal opcodes), these cannot be used as variable or label names
-    override val opcodeNames = setOf("adc", "ahx", "alr", "anc", "and", "ane", "arr", "asl", "asr", "axs", "bcc", "bcs",
-            "beq", "bge", "bit", "blt", "bmi", "bne", "bpl", "brk", "bvc", "bvs", "clc",
-            "cld", "cli", "clv", "cmp", "cpx", "cpy", "dcm", "dcp", "dec", "dex", "dey",
-            "eor", "gcc", "gcs", "geq", "gge", "glt", "gmi", "gne", "gpl", "gvc", "gvs",
-            "inc", "ins", "inx", "iny", "isb", "isc", "jam", "jmp", "jsr", "lae", "las",
-            "lax", "lda", "lds", "ldx", "ldy", "lsr", "lxa", "nop", "ora", "pha", "php",
-            "pla", "plp", "rla", "rol", "ror", "rra", "rti", "rts", "sax", "sbc", "sbx",
-            "sec", "sed", "sei", "sha", "shl", "shr", "shs", "shx", "shy", "slo", "sre",
-            "sta", "stx", "sty", "tas", "tax", "tay", "tsx", "txa", "txs", "tya", "xaa")
-
-
-    class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
-
-        override val SCRATCH_B1 = 0x02      // temp storage for a single byte
-        override val SCRATCH_REG = 0x03     // temp storage for a register, must be B1+1
-        override val SCRATCH_W1 = 0xfb      // temp storage 1 for a word  $fb+$fc
-        override val SCRATCH_W2 = 0xfd      // temp storage 2 for a word  $fb+$fc
-
-
-        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(0x04..0xf9)
-                free.add(0xff)
-                free.removeAll(listOf(0xa0, 0xa1, 0xa2, 0x91, 0xc0, 0xc5, 0xcb, 0xf5, 0xf6))        // these are updated by IRQ
-            } else {
-                if (options.zeropage == ZeropageType.KERNALSAFE || options.zeropage == ZeropageType.FLOATSAFE) {
-                    free.addAll(listOf(
-                            0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
-                            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'
-                    ))
-                }
-
-                if (options.zeropage == ZeropageType.FLOATSAFE) {
-                    // remove the zeropage locations used for floating point operations from the free list
-                    free.removeAll(listOf(
-                            0x22, 0x23, 0x24, 0x25,
-                            0x10, 0x11, 0x12, 0x26, 0x27, 0x28, 0x29, 0x2a,
-                            0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
-                            0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
-                            0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72,
-                            0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0xff
-                    ))
-                }
-
-                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(0x04, 0x05, 0x06, 0x0a, 0x0e,
-                            0x92, 0x96, 0x9b, 0x9c, 0x9e, 0x9f, 0xa5, 0xa6,
-                            0xb0, 0xb1, 0xbe, 0xbf, 0xf9))
-                } else {
-                    // don't use the zeropage at all
-                    free.clear()
-                }
-            }
-
-            removeReservedFromFreePool()
-        }
-    }
-
-    data class Mflpt5(val b0: Short, val b1: Short, val b2: Short, val b3: Short, val b4: Short):
-        IMachineFloat {
-
-        companion object {
-            val zero = Mflpt5(0, 0, 0, 0, 0)
-            fun fromNumber(num: Number): Mflpt5 {
-                // see https://en.wikipedia.org/wiki/Microsoft_Binary_Format
-                // and https://sourceforge.net/p/acme-crossass/code-0/62/tree/trunk/ACME_Lib/cbm/mflpt.a
-                // and https://en.wikipedia.org/wiki/IEEE_754-1985
-
-                val flt = num.toDouble()
-                if (flt < FLOAT_MAX_NEGATIVE || flt > FLOAT_MAX_POSITIVE)
-                    throw 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: $this")
-                    exponent == 0 -> zero
-                    else -> {
-                        val mantLong = mantissa.toLong()
-                        Mflpt5(
-                                exponent.toShort(),
-                                (mantLong.and(0x7f000000L) ushr 24).or(sign).toShort(),
-                                (mantLong.and(0x00ff0000L) ushr 16).toShort(),
-                                (mantLong.and(0x0000ff00L) ushr 8).toShort(),
-                                (mantLong.and(0x000000ffL)).toShort())
-                    }
-                }
-            }
-        }
-
-        override fun toDouble(): Double {
-            if (this == zero) return 0.0
-            val exp = b0 - 128
-            val sign = (b1.toInt() and 0x80) > 0
-            val number = 0x80000000L.or(b1.toLong() shl 24).or(b2.toLong() shl 16).or(b3.toLong() shl 8).or(b4.toLong())
-            val result = number.toDouble() * (2.0).pow(exp) / 0x100000000
-            return if (sign) -result else result
-        }
-
-        override fun makeFloatFillAsm(): String {
-            val b0 = "$" + 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"
-        }
-    }
-}

codeGeneration/src/prog8/compiler/target/cbm/AssemblyProgram.kt

@@ -1,103 +0,0 @@
-package prog8.compiler.target.cbm
-
-import com.github.michaelbull.result.Ok
-import com.github.michaelbull.result.Result
-import com.github.michaelbull.result.mapError
-import prog8.compilerinterface.CompilationOptions
-import prog8.compilerinterface.IAssemblyProgram
-import prog8.compilerinterface.OutputType
-import prog8.compilerinterface.generatedLabelPrefix
-import prog8.parser.SourceCode
-import java.io.File
-import java.nio.file.Path
-import kotlin.io.path.Path
-import kotlin.io.path.isRegularFile
-
-
-internal const val viceMonListPostfix = "vice-mon-list"
-
-class AssemblyProgram(
-        override val valid: Boolean,
-        override val name: String,
-        outputDir: Path,
-        private val compTarget: String) : IAssemblyProgram {
-
-    private val assemblyFile = outputDir.resolve("$name.asm")
-    private val prgFile = outputDir.resolve("$name.prg")
-    private val binFile = outputDir.resolve("$name.bin")
-    private val viceMonListFile = outputDir.resolve("$name.$viceMonListPostfix")
-
-    override fun assemble(quiet: Boolean, options: CompilationOptions): Int {
-        // 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", "-Wno-shadow", // "-Werror",
-                "--dump-labels", "--vice-labels", "-l", viceMonListFile.toString(), "--no-monitor")
-
-        if(quiet)
-            command.add("--quiet")
-
-        val outFile = when (options.output) {
-            OutputType.PRG -> {
-                command.add("--cbm-prg")
-                println("\nCreating prg for target $compTarget.")
-                prgFile
-            }
-            OutputType.RAW -> {
-                command.add("--nostart")
-                println("\nCreating raw binary for target $compTarget.")
-                binFile
-            }
-        }
-        command.addAll(listOf("--output", outFile.toString(), assemblyFile.toString()))
-
-        val proc = ProcessBuilder(command).inheritIO().start()
-        val result = proc.waitFor()
-        if (result == 0) {
-            removeGeneratedLabelsFromMonlist()
-            generateBreakpointList()
-        }
-        return result
-    }
-
-    private fun removeGeneratedLabelsFromMonlist() {
-        val pattern = Regex("""al (\w+) \S+${generatedLabelPrefix}.+?""")
-        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, "; vice monitor breakpoint list now follows")
-        breakpoints.add(1, "; $num breakpoints have been defined")
-        breakpoints.add(2, "del")
-        viceMonListFile.toFile().appendText(breakpoints.joinToString("\n") + "\n")
-    }
-}
-
-
-internal fun loadAsmIncludeFile(filename: String, source: SourceCode): Result<String, NoSuchFileException> {
-    return if (filename.startsWith(SourceCode.libraryFilePrefix)) {
-        return com.github.michaelbull.result.runCatching {
-            SourceCode.Resource("/prog8lib/${filename.substring(SourceCode.libraryFilePrefix.length)}").readText()
-        }.mapError { NoSuchFileException(File(filename)) }
-    } else {
-        val sib = Path(source.origin).resolveSibling(filename)
-        if (sib.isRegularFile())
-            Ok(SourceCode.File(sib).readText())
-        else
-            Ok(SourceCode.File(Path(filename)).readText())
-    }
-}

codeGeneration/src/prog8/compiler/target/cpu6502/codegen/AsmOptimizer.kt

@@ -1,242 +0,0 @@
-package prog8.compiler.target.cpu6502.codegen
-
-
-// note: see https://wiki.nesdev.com/w/index.php/6502_assembly_optimisations
-
-
-fun optimizeAssembly(lines: MutableList<String>): Int {
-
-    var numberOfOptimizations = 0
-
-    var linesByFour = getLinesBy(lines, 4)
-
-    var mods = optimizeUselessStackByteWrites(linesByFour)
-    if(mods.isNotEmpty()) {
-        apply(mods, lines)
-        linesByFour = getLinesBy(lines, 4)
-        numberOfOptimizations++
-    }
-
-    mods = optimizeIncDec(linesByFour)
-    if(mods.isNotEmpty()) {
-        apply(mods, lines)
-        linesByFour = getLinesBy(lines, 4)
-        numberOfOptimizations++
-    }
-
-    mods = optimizeCmpSequence(linesByFour)
-    if(mods.isNotEmpty()) {
-        apply(mods, lines)
-        linesByFour = getLinesBy(lines, 4)
-        numberOfOptimizations++
-    }
-
-    mods = optimizeStoreLoadSame(linesByFour)
-    if(mods.isNotEmpty()) {
-        apply(mods, lines)
-        linesByFour = getLinesBy(lines, 4)
-        numberOfOptimizations++
-    }
-
-    mods= optimizeJsrRts(linesByFour)
-    if(mods.isNotEmpty()) {
-        apply(mods, lines)
-        linesByFour = getLinesBy(lines, 4)
-        numberOfOptimizations++
-    }
-
-    var linesByFourteen = getLinesBy(lines, 14)
-    mods = optimizeSameAssignments(linesByFourteen)
-    if(mods.isNotEmpty()) {
-        apply(mods, lines)
-        linesByFourteen = getLinesBy(lines, 14)
-        numberOfOptimizations++
-    }
-
-    // TODO more assembly optimizations
-
-    return numberOfOptimizations
-}
-
-private class Modification(val lineIndex: Int, val remove: Boolean, val replacement: String?)
-
-private fun apply(modifications: List<Modification>, lines: MutableList<String>) {
-    for (modification in modifications.sortedBy { it.lineIndex }.reversed()) {
-        if(modification.remove)
-            lines.removeAt(modification.lineIndex)
-        else
-            lines[modification.lineIndex] = modification.replacement!!
-    }
-}
-
-private fun getLinesBy(lines: MutableList<String>, windowSize: Int) =
-// all lines (that aren't empty or comments) in sliding windows of certain size
-        lines.withIndex().filter { it.value.isNotBlank() && !it.value.trimStart().startsWith(';') }.windowed(windowSize, partialWindows = false)
-
-private fun optimizeCmpSequence(linesByFour: List<List<IndexedValue<String>>>): List<Modification> {
-    // when statement (on bytes) generates a sequence of:
-    //	 lda  $ce01,x
-    //	 cmp  #$20
-    //	 beq  check_prog8_s72choice_32
-    //	 lda  $ce01,x
-    //	 cmp  #$21
-    //	 beq  check_prog8_s73choice_33
-    // the repeated lda can be removed
-    val mods = mutableListOf<Modification>()
-    for(lines in linesByFour) {
-        if(lines[0].value.trim()=="lda  P8ESTACK_LO+1,x" &&
-                lines[1].value.trim().startsWith("cmp ") &&
-                lines[2].value.trim().startsWith("beq ") &&
-                lines[3].value.trim()=="lda  P8ESTACK_LO+1,x") {
-            mods.add(Modification(lines[3].index, true, null)) // remove the second lda
-        }
-    }
-    return mods
-}
-
-private fun optimizeUselessStackByteWrites(linesByFour: List<List<IndexedValue<String>>>): List<Modification> {
-    // sta on stack, dex, inx, lda from stack -> eliminate this useless stack byte write
-    // this is a lot harder for word values because the instruction sequence varies.
-    val mods = mutableListOf<Modification>()
-    for(lines in linesByFour) {
-        if(lines[0].value.trim()=="sta  P8ESTACK_LO,x" &&
-                lines[1].value.trim()=="dex" &&
-                lines[2].value.trim()=="inx" &&
-                lines[3].value.trim()=="lda  P8ESTACK_LO,x") {
-            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 optimizeSameAssignments(linesByFourteen: List<List<IndexedValue<String>>>): List<Modification> {
-
-    // optimize sequential assignments of the isSameAs value to various targets (bytes, words, floats)
-    // the float one is the one that requires 2*7=14 lines of code to check...
-    // @todo a better place to do this is in the Compiler instead and transform the Ast, or the AsmGen, and never even create the inefficient asm in the first place...
-
-    val mods = mutableListOf<Modification>()
-    for (pair in linesByFourteen) {
-        val first = pair[0].value.trimStart()
-        val second = pair[1].value.trimStart()
-        val third = pair[2].value.trimStart()
-        val fourth = pair[3].value.trimStart()
-        val fifth = pair[4].value.trimStart()
-        val sixth = pair[5].value.trimStart()
-        val seventh = pair[6].value.trimStart()
-        val eighth = pair[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 isSameAs word -->  remove second lda/ldy pair (fifth and sixth lines)
-                mods.add(Modification(pair[4].index, true, null))
-                mods.add(Modification(pair[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 isSameAs-value / sta ?  -> remove second lda (third line)
-                mods.add(Modification(pair[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 = pair[8].value.trimStart()
-            val tenth = pair[9].value.trimStart()
-            val eleventh = pair[10].value.trimStart()
-            val twelveth = pair[11].value.trimStart()
-            val thirteenth = pair[12].value.trimStart()
-            val fourteenth = pair[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(pair[7].index, true, null))
-                    mods.add(Modification(pair[8].index, true, null))
-                    mods.add(Modification(pair[9].index, true, null))
-                    mods.add(Modification(pair[10].index, true, null))
-                }
-            }
-        }
-    }
-    return mods
-}
-
-private fun optimizeStoreLoadSame(linesByFour: List<List<IndexedValue<String>>>): List<Modification> {
-    // sta X + lda X,  sty X + ldy X,   stx X + ldx X  -> the second instruction can OFTEN be eliminated
-    // TODO this is not true if X is not a regular RAM memory address (but instead mapped I/O or ROM) but how does this code know?
-    val mods = mutableListOf<Modification>()
-    for (pair in linesByFour) {
-        val first = pair[0].value.trimStart()
-        val second = pair[1].value.trimStart()
-
-        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 ")) ||
-                (first.startsWith("sta ") && second.startsWith("lda ")) ||
-                (first.startsWith("sty ") && second.startsWith("ldy ")) ||
-                (first.startsWith("stx ") && second.startsWith("ldx "))
-        ) {
-            val third = pair[2].value.trimStart()
-            if(!third.startsWith("b")) {
-                // no branch instruction follows, we can potentiall remove the load instruction
-                val firstLoc = first.substring(4).trimStart()
-                val secondLoc = second.substring(4).trimStart()
-                if (firstLoc == secondLoc) {
-                    mods.add(Modification(pair[1].index, true, null))
-                }
-            }
-        }
-    }
-    return mods
-}
-
-private fun optimizeIncDec(linesByFour: List<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 (pair in linesByFour) {
-        val first = pair[0].value
-        val second = pair[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)
-                || (" dey" in first || "\tdey" in first) && (" iny" in second || "\tiny" in second)
-                || (" dex" in first || "\tdex" in first) && (" inx" in second || "\tinx" in second)) {
-            mods.add(Modification(pair[0].index, true, null))
-            mods.add(Modification(pair[1].index, true, null))
-        }
-    }
-    return mods
-}
-
-private fun optimizeJsrRts(linesByFour: List<List<IndexedValue<String>>>): List<Modification> {
-    // jsr Sub + rts -> jmp Sub
-    val mods = mutableListOf<Modification>()
-    for (pair in linesByFour) {
-        val first = pair[0].value
-        val second = pair[1].value
-        if ((" jsr" in first || "\tjsr" in first ) && (" rts" in second || "\trts" in second)) {
-            mods += Modification(pair[0].index, false, pair[0].value.replace("jsr", "jmp"))
-            mods += Modification(pair[1].index, true, null)
-        }
-    }
-    return mods
-}

codeGeneration/src/prog8/compiler/target/cpu6502/codegen/FunctionCallAsmGen.kt

@@ -1,372 +0,0 @@
-package prog8.compiler.target.cpu6502.codegen
-
-import prog8.ast.IFunctionCall
-import prog8.ast.Node
-import prog8.ast.Program
-import prog8.ast.base.*
-import prog8.ast.expressions.*
-import prog8.ast.statements.InlineAssembly
-import prog8.ast.statements.RegisterOrStatusflag
-import prog8.ast.statements.Subroutine
-import prog8.ast.statements.SubroutineParameter
-import prog8.compiler.target.AssemblyError
-import prog8.compiler.target.cpu6502.codegen.assignment.AsmAssignSource
-import prog8.compiler.target.cpu6502.codegen.assignment.AsmAssignTarget
-import prog8.compiler.target.cpu6502.codegen.assignment.AsmAssignment
-import prog8.compiler.target.cpu6502.codegen.assignment.TargetStorageKind
-import prog8.compilerinterface.CpuType
-
-
-internal class FunctionCallAsmGen(private val program: Program, private val asmgen: AsmGen) {
-
-    internal fun translateFunctionCallStatement(stmt: IFunctionCall) {
-        saveXbeforeCall(stmt)
-        translateFunctionCall(stmt)
-        restoreXafterCall(stmt)
-        // just ignore any result values from the function call.
-    }
-
-    internal fun saveXbeforeCall(stmt: IFunctionCall) {
-        val sub = stmt.target.targetSubroutine(program) ?: throw AssemblyError("undefined subroutine ${stmt.target}")
-        if(sub.shouldSaveX()) {
-            val regSaveOnStack = sub.asmAddress==null       // rom-routines don't require registers to be saved on stack, normal subroutines do because they can contain nested calls
-            if(regSaveOnStack)
-                asmgen.saveRegisterStack(CpuRegister.X, sub.shouldKeepA().saveOnEntry)
-            else
-                asmgen.saveRegisterLocal(CpuRegister.X, (stmt as Node).definingSubroutine!!)
-        }
-    }
-
-    internal fun restoreXafterCall(stmt: IFunctionCall) {
-        val sub = stmt.target.targetSubroutine(program) ?: throw AssemblyError("undefined subroutine ${stmt.target}")
-        if(sub.shouldSaveX()) {
-            val regSaveOnStack = sub.asmAddress==null       // rom-routines don't require registers to be saved on stack, normal subroutines do because they can contain nested calls
-            if(regSaveOnStack)
-                asmgen.restoreRegisterStack(CpuRegister.X, sub.shouldKeepA().saveOnReturn)
-            else
-                asmgen.restoreRegisterLocal(CpuRegister.X)
-        }
-    }
-
-    internal fun translateFunctionCall(stmt: IFunctionCall) {
-        // Output only the code to set up the parameters and perform the actual call
-        // NOTE: does NOT output the code to deal with the result values!
-        // NOTE: does NOT output code to save/restore the X register for this call! Every caller should deal with this in their own way!!
-        //       (you can use subroutine.shouldSaveX() and saveX()/restoreX() routines as a help for this)
-
-        val sub = stmt.target.targetSubroutine(program) ?: throw AssemblyError("undefined subroutine ${stmt.target}")
-        val subName = asmgen.asmSymbolName(stmt.target)
-        if(stmt.args.isNotEmpty()) {
-
-            if(sub.asmParameterRegisters.isEmpty()) {
-                // via variables
-                for(arg in sub.parameters.withIndex().zip(stmt.args)) {
-                    argumentViaVariable(sub, arg.first, arg.second)
-                }
-            } else {
-                require(sub.isAsmSubroutine)
-                if(sub.parameters.size==1) {
-                    // just a single parameter, no risk of clobbering registers
-                    argumentViaRegister(sub, IndexedValue(0, sub.parameters.single()), stmt.args[0])
-                } else {
-
-                    fun isNoClobberRisk(expr: Expression): Boolean {
-                        if(expr is AddressOf ||
-                                expr is NumericLiteralValue ||
-                                expr is StringLiteralValue ||
-                                expr is ArrayLiteralValue ||
-                                expr is IdentifierReference)
-                            return true
-
-                        if(expr is FunctionCall) {
-                            if(expr.target.nameInSource==listOf("lsb") || expr.target.nameInSource==listOf("msb"))
-                                return isNoClobberRisk(expr.args[0])
-                            if(expr.target.nameInSource==listOf("mkword"))
-                                return isNoClobberRisk(expr.args[0]) && isNoClobberRisk(expr.args[1])
-                        }
-
-                        return false
-                    }
-
-                    when {
-                        stmt.args.all {isNoClobberRisk(it)} -> {
-                            // There's no risk of clobbering for these simple argument types. Optimize the register loading directly from these values.
-                            // register assignment order: 1) cx16 virtual word registers, 2) actual CPU registers, 3) CPU Carry status flag.
-                            val argsInfo = sub.parameters.withIndex().zip(stmt.args).zip(sub.asmParameterRegisters)
-                            val (cx16virtualRegs, args2) = argsInfo.partition { it.second.registerOrPair in Cx16VirtualRegisters }
-                            val (cpuRegs, statusRegs) = args2.partition { it.second.registerOrPair!=null }
-                            for(arg in cx16virtualRegs)
-                                argumentViaRegister(sub, arg.first.first, arg.first.second)
-                            for(arg in cpuRegs)
-                                argumentViaRegister(sub, arg.first.first, arg.first.second)
-                            for(arg in statusRegs)
-                                argumentViaRegister(sub, arg.first.first, arg.first.second)
-                        }
-                        else -> {
-                            // Risk of clobbering due to complex expression args. Evaluate first, then assign registers.
-                            registerArgsViaStackEvaluation(stmt, sub)
-                        }
-                    }
-                }
-            }
-        }
-
-        if(!sub.inline || !asmgen.options.optimize) {
-            asmgen.out("  jsr  $subName")
-        } else {
-            // inline the subroutine.
-            // we do this by copying the subroutine's statements at the call site.
-            // NOTE: *if* there is a return statement, it will be the only one, and the very last statement of the subroutine
-            // (this condition has been enforced by an ast check earlier)
-
-            // note: for now, this is only reliably supported for asmsubs.
-            if(!sub.isAsmSubroutine)
-                throw AssemblyError("can only reliably inline asmsub routines at this time")
-
-            asmgen.out("  \t; inlined routine follows: ${sub.name}")
-            val assembly = sub.statements.single() as InlineAssembly
-            asmgen.translate(assembly)
-            asmgen.out("  \t; inlined routine end: ${sub.name}")
-        }
-
-        // remember: dealing with the X register and/or dealing with return values is the responsibility of the caller
-    }
-
-    private fun registerArgsViaStackEvaluation(stmt: IFunctionCall, sub: Subroutine) {
-        // this is called when one or more of the arguments are 'complex' and
-        // cannot be assigned to a register easily or risk clobbering other registers.
-        // TODO find another way to prepare the arguments, without using the eval stack
-
-        if(sub.parameters.isEmpty())
-            return
-
-
-        // 1. load all arguments reversed onto the stack: first arg goes last (is on top).
-
-        for (arg in stmt.args.reversed())
-            asmgen.translateExpression(arg)
-
-        // TODO here's an alternative to the above, but for now generates bigger code due to intermediate register steps:
-//        for (arg in stmt.args.reversed()) {
-//            // note this stuff below is needed to (eventually) avoid calling asmgen.translateExpression()
-//            // TODO also This STILL requires the translateNormalAssignment() to be fixed to avoid stack eval for expressions...
-//            val dt = arg.inferType(program).getOr(DataType.UNDEFINED)
-//            asmgen.assignExpressionTo(arg, AsmAssignTarget(TargetStorageKind.STACK, program, asmgen, dt, sub))
-//        }
-
-        var argForCarry: IndexedValue<Pair<Expression, RegisterOrStatusflag>>? = null
-        var argForXregister: IndexedValue<Pair<Expression, RegisterOrStatusflag>>? = null
-        var argForAregister: IndexedValue<Pair<Expression, RegisterOrStatusflag>>? = null
-
-        asmgen.out("  inx")     // align estack pointer
-
-        for(argi in stmt.args.zip(sub.asmParameterRegisters).withIndex()) {
-            val plusIdxStr = if(argi.index==0) "" else "+${argi.index}"
-            when {
-                argi.value.second.statusflag == Statusflag.Pc -> {
-                    require(argForCarry == null)
-                    argForCarry = argi
-                }
-                argi.value.second.statusflag != null -> throw AssemblyError("can only use Carry as status flag parameter")
-                argi.value.second.registerOrPair in arrayOf(RegisterOrPair.X, RegisterOrPair.AX, RegisterOrPair.XY) -> {
-                    require(argForXregister==null)
-                    argForXregister = argi
-                }
-                argi.value.second.registerOrPair in arrayOf(RegisterOrPair.A, RegisterOrPair.AY) -> {
-                    require(argForAregister == null)
-                    argForAregister = argi
-                }
-                argi.value.second.registerOrPair == RegisterOrPair.Y -> {
-                    asmgen.out("  ldy  P8ESTACK_LO$plusIdxStr,x")
-                }
-                argi.value.second.registerOrPair in Cx16VirtualRegisters -> {
-                    // immediately output code to load the virtual register, to avoid clobbering the A register later
-                    when (sub.parameters[argi.index].type) {
-                        in ByteDatatypes -> {
-                            // only load the lsb of the virtual register
-                            asmgen.out(
-                                """
-                                lda  P8ESTACK_LO$plusIdxStr,x
-                                sta  cx16.${argi.value.second.registerOrPair.toString().lowercase()}
-                            """)
-                            if (asmgen.isTargetCpu(CpuType.CPU65c02))
-                                asmgen.out(
-                                    "  stz  cx16.${
-                                        argi.value.second.registerOrPair.toString().lowercase()
-                                    }+1")
-                            else
-                                asmgen.out(
-                                    "  lda  #0 |  sta  cx16.${
-                                        argi.value.second.registerOrPair.toString().lowercase()
-                                    }+1")
-                        }
-                        in WordDatatypes, in IterableDatatypes ->
-                            asmgen.out(
-                                """
-                                lda  P8ESTACK_LO$plusIdxStr,x
-                                sta  cx16.${argi.value.second.registerOrPair.toString().lowercase()}
-                                lda  P8ESTACK_HI$plusIdxStr,x
-                                sta  cx16.${
-                                    argi.value.second.registerOrPair.toString().lowercase()
-                                }+1
-                            """)
-                        else -> throw AssemblyError("weird dt")
-                    }
-                }
-                else -> throw AssemblyError("weird argument")
-            }
-        }
-
-        if(argForCarry!=null) {
-            val plusIdxStr = if(argForCarry.index==0) "" else "+${argForCarry.index}"
-            asmgen.out("""
-                lda  P8ESTACK_LO$plusIdxStr,x
-                beq  +
-                sec
-                bcs  ++
-+               clc
-+               php""")             // push the status flags
-        }
-
-        if(argForAregister!=null) {
-            val plusIdxStr = if(argForAregister.index==0) "" else "+${argForAregister.index}"
-            when(argForAregister.value.second.registerOrPair) {
-                RegisterOrPair.A -> asmgen.out("  lda  P8ESTACK_LO$plusIdxStr,x")
-                RegisterOrPair.AY -> asmgen.out("  lda  P8ESTACK_LO$plusIdxStr,x |  ldy  P8ESTACK_HI$plusIdxStr,x")
-                else -> throw AssemblyError("weird arg")
-            }
-        }
-
-        if(argForXregister!=null) {
-            val plusIdxStr = if(argForXregister.index==0) "" else "+${argForXregister.index}"
-
-            if(argForAregister!=null)
-                asmgen.out("  pha")
-            when(argForXregister.value.second.registerOrPair) {
-                RegisterOrPair.X -> asmgen.out("  lda  P8ESTACK_LO$plusIdxStr,x |  tax")
-                RegisterOrPair.AX -> asmgen.out("  ldy  P8ESTACK_LO$plusIdxStr,x |  lda  P8ESTACK_HI$plusIdxStr,x |  tax |  tya")
-                RegisterOrPair.XY -> asmgen.out("  ldy  P8ESTACK_HI$plusIdxStr,x |  lda  P8ESTACK_LO$plusIdxStr,x |  tax")
-                else -> throw AssemblyError("weird arg")
-            }
-            if(argForAregister!=null)
-                asmgen.out("  pla")
-        } else {
-            repeat(sub.parameters.size - 1) { asmgen.out("  inx") }       // unwind stack
-        }
-
-        if(argForCarry!=null)
-            asmgen.out("  plp")       // set the carry flag back to correct value
-    }
-
-    private fun argumentViaVariable(sub: Subroutine, parameter: IndexedValue<SubroutineParameter>, value: Expression) {
-        // pass parameter via a regular variable (not via registers)
-        val valueIDt = value.inferType(program)
-        if(!valueIDt.isKnown)
-            throw AssemblyError("unknown dt")
-        val valueDt = valueIDt.getOr(DataType.UNDEFINED)
-        if(!isArgumentTypeCompatible(valueDt, parameter.value.type))
-            throw AssemblyError("argument type incompatible")
-
-        val varName = asmgen.asmVariableName(sub.scopedname+"."+parameter.value.name)
-        asmgen.assignExpressionToVariable(value, varName, parameter.value.type, sub)
-    }
-
-    private fun argumentViaRegister(sub: Subroutine, parameter: IndexedValue<SubroutineParameter>, value: Expression) {
-        // pass argument via a register parameter
-        val valueIDt = value.inferType(program)
-        if(!valueIDt.isKnown)
-            throw AssemblyError("unknown dt")
-        val valueDt = valueIDt.getOr(DataType.UNDEFINED)
-        if(!isArgumentTypeCompatible(valueDt, parameter.value.type))
-            throw AssemblyError("argument type incompatible")
-
-        val paramRegister = sub.asmParameterRegisters[parameter.index]
-        val statusflag = paramRegister.statusflag
-        val register = paramRegister.registerOrPair
-        val requiredDt = parameter.value.type
-        if(requiredDt!=valueDt) {
-            if(valueDt largerThan requiredDt)
-                throw AssemblyError("can only convert byte values to word param types")
-        }
-        if (statusflag!=null) {
-            if(requiredDt!=valueDt)
-                throw AssemblyError("for statusflag, byte value is required")
-            if (statusflag == Statusflag.Pc) {
-                // this param needs to be set last, right before the jsr
-                // for now, this is already enforced on the subroutine definition by the Ast Checker
-                when(value) {
-                    is NumericLiteralValue -> {
-                        val carrySet = value.number.toInt() != 0
-                        asmgen.out(if(carrySet) "  sec" else "  clc")
-                    }
-                    is IdentifierReference -> {
-                        val sourceName = asmgen.asmVariableName(value)
-                        asmgen.out("""
-                pha
-                lda  $sourceName
-                beq  +
-                sec  
-                bcs  ++
-    +           clc
-    +           pla
-    """)
-                    }
-                    else -> {
-                        asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
-                        asmgen.out("""
-                                    beq  +
-                                    sec
-                                    bcs  ++
-    +                               clc
-    +""")
-                    }
-                }
-            } else throw AssemblyError("can only use Carry as status flag parameter")
-        }
-        else {
-            // via register or register pair
-            register!!
-            if(requiredDt largerThan valueDt) {
-                // we need to sign extend the source, do this via temporary word variable
-                asmgen.assignExpressionToVariable(value, "P8ZP_SCRATCH_W1", DataType.UBYTE, sub)
-                asmgen.signExtendVariableLsb("P8ZP_SCRATCH_W1", valueDt)
-                asmgen.assignVariableToRegister("P8ZP_SCRATCH_W1", register)
-            } else {
-                val target: AsmAssignTarget =
-                    if(parameter.value.type in ByteDatatypes && (register==RegisterOrPair.AX || register == RegisterOrPair.AY || register==RegisterOrPair.XY || register in Cx16VirtualRegisters))
-                        AsmAssignTarget(TargetStorageKind.REGISTER, program, asmgen, parameter.value.type, sub, register = register)
-                    else
-                        AsmAssignTarget.fromRegisters(register, false, sub, program, asmgen)
-                val src = if(valueDt in PassByReferenceDatatypes) {
-                    if(value is IdentifierReference) {
-                        val addr = AddressOf(value, Position.DUMMY)
-                        AsmAssignSource.fromAstSource(addr, program, asmgen).adjustSignedUnsigned(target)
-                    } else {
-                        AsmAssignSource.fromAstSource(value, program, asmgen).adjustSignedUnsigned(target)
-                    }
-                } else {
-                    AsmAssignSource.fromAstSource(value, program, asmgen).adjustSignedUnsigned(target)
-                }
-                asmgen.translateNormalAssignment(AsmAssignment(src, target, false, program.memsizer, Position.DUMMY))
-            }
-        }
-    }
-
-    private fun isArgumentTypeCompatible(argType: DataType, paramType: DataType): Boolean {
-        if(argType isAssignableTo paramType)
-            return true
-        if(argType in ByteDatatypes && paramType in ByteDatatypes)
-            return true
-        if(argType in WordDatatypes && paramType in WordDatatypes)
-            return true
-
-        // we have a special rule for some types.
-        // strings are assignable to UWORD, for example, and vice versa
-        if(argType==DataType.STR && paramType==DataType.UWORD)
-            return true
-        if(argType==DataType.UWORD && paramType == DataType.STR)
-            return true
-
-        return false
-    }
-}

codeGeneration/src/prog8/compiler/target/cx16/CX16MachineDefinition.kt

@@ -1,124 +0,0 @@
-package prog8.compiler.target.cx16
-
-import prog8.compiler.target.c64.C64MachineDefinition
-import prog8.compiler.target.cbm.viceMonListPostfix
-import prog8.compilerinterface.*
-import java.io.IOException
-import java.nio.file.Path
-
-
-object CX16MachineDefinition: IMachineDefinition {
-
-    override val cpu = CpuType.CPU65c02
-
-    // 5-byte cbm MFLPT format limitations:
-    override val FLOAT_MAX_POSITIVE = 1.7014118345e+38         // bytes: 255,127,255,255,255
-    override val FLOAT_MAX_NEGATIVE = -1.7014118345e+38        // bytes: 255,255,255,255,255
-    override val FLOAT_MEM_SIZE = 5
-    override val POINTER_MEM_SIZE = 2
-    override val BASIC_LOAD_ADDRESS = 0x0801
-    override val RAW_LOAD_ADDRESS = 0x8000
-
-    // the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
-    override val ESTACK_LO = 0x0400        //  $0400-$04ff inclusive
-    override val ESTACK_HI = 0x0500        //  $0500-$05ff inclusive
-
-    override lateinit var zeropage: Zeropage
-
-    override fun getFloat(num: Number) = C64MachineDefinition.Mflpt5.fromNumber(num)
-    override fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
-        return if (compilerOptions.launcher == LauncherType.BASIC || compilerOptions.output == OutputType.PRG)
-            listOf("syslib")
-        else
-            emptyList()
-    }
-
-    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
-        val emulatorName: String
-        val extraArgs: List<String>
-
-        when(selectedEmulator) {
-            1 -> {
-                emulatorName = "x16emu"
-                extraArgs = emptyList()
-            }
-            2 -> {
-                emulatorName = "box16"
-                extraArgs = listOf("-sym", "${programNameWithPath}.$viceMonListPostfix")
-            }
-            else -> {
-                System.err.println("Cx16 target only supports x16emu and box16 emulators.")
-                return
-            }
-        }
-
-        for(emulator in listOf(emulatorName)) {
-            println("\nStarting Commander X16 emulator $emulator...")
-            val cmdline = listOf(emulator, "-scale", "2", "-run", "-prg", "${programNameWithPath}.prg") + extraArgs
-            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 isRegularRAMaddress(address: Int): Boolean = address < 0x9f00 || address in 0xa000..0xbfff
-
-    override fun initializeZeropage(compilerOptions: CompilationOptions) {
-        zeropage = CX16Zeropage(compilerOptions)
-    }
-
-    // 6502 opcodes (including aliases and illegal opcodes), these cannot be used as variable or label names
-    override val opcodeNames = setOf("adc", "and", "asl", "bcc", "bcs",
-            "beq", "bge", "bit", "blt", "bmi", "bne", "bpl", "brk", "bvc", "bvs", "clc",
-            "cld", "cli", "clv", "cmp", "cpx", "cpy", "dec", "dex", "dey",
-            "eor", "gcc", "gcs", "geq", "gge", "glt", "gmi", "gne", "gpl", "gvc", "gvs",
-            "inc", "inx", "iny", "jmp", "jsr",
-            "lda", "ldx", "ldy", "lsr", "nop", "ora", "pha", "php",
-            "pla", "plp", "rol", "ror", "rti", "rts", "sbc",
-            "sec", "sed", "sei",
-            "sta", "stx", "sty", "tax", "tay", "tsx", "txa", "txs", "tya",
-            "bra", "phx", "phy", "plx", "ply", "stz", "trb", "tsb", "bbr", "bbs",
-            "rmb", "smb", "stp", "wai")
-
-
-    class CX16Zeropage(options: CompilationOptions) : Zeropage(options) {
-
-        override val SCRATCH_B1 = 0x7a      // temp storage for a single byte
-        override val SCRATCH_REG = 0x7b     // temp storage for a register, must be B1+1
-        override val SCRATCH_W1 = 0x7c      // temp storage 1 for a word  $7c+$7d
-        override val SCRATCH_W2 = 0x7e      // temp storage 2 for a word  $7e+$7f
-
-
-        init {
-            if (options.floats && options.zeropage !in arrayOf(ZeropageType.BASICSAFE, ZeropageType.DONTUSE ))
-                throw InternalCompilerException("when floats are enabled, zero page type should be 'basicsafe' or 'dontuse'")
-
-            // the addresses 0x02 to 0x21 (inclusive) are taken for sixteen virtual 16-bit api registers.
-
-            when (options.zeropage) {
-                ZeropageType.FULL -> {
-                    free.addAll(0x22..0xff)
-                }
-                ZeropageType.KERNALSAFE -> {
-                    free.addAll(0x22..0x7f)
-                    free.addAll(0xa9..0xff)
-                }
-                ZeropageType.BASICSAFE -> {
-                    free.addAll(0x22..0x7f)
-                }
-                ZeropageType.DONTUSE -> {
-                    free.clear() // don't use zeropage at all
-                }
-                else -> throw InternalCompilerException("for this machine target, zero page type 'floatsafe' is not available. ${options.zeropage}")
-            }
-
-            removeReservedFromFreePool()
-        }
-    }
-}

codeGeneration/test/AsmGenTests.kt

@@ -1,151 +0,0 @@
-package prog8tests.asmgen
-
-import org.hamcrest.MatcherAssert.assertThat
-import org.hamcrest.Matchers.equalTo
-import org.junit.jupiter.api.Test
-import org.junit.jupiter.api.TestInstance
-import prog8.ast.Module
-import prog8.ast.Program
-import prog8.ast.base.DataType
-import prog8.ast.base.Position
-import prog8.ast.base.RegisterOrPair
-import prog8.ast.base.VarDeclType
-import prog8.ast.expressions.AddressOf
-import prog8.ast.expressions.IdentifierReference
-import prog8.ast.expressions.NumericLiteralValue
-import prog8.ast.statements.*
-import prog8.compiler.target.C64Target
-import prog8.compiler.target.c64.C64MachineDefinition
-import prog8.compiler.target.cpu6502.codegen.AsmGen
-import prog8.compilerinterface.*
-import prog8.parser.SourceCode
-import prog8tests.asmgen.helpers.DummyFunctions
-import prog8tests.asmgen.helpers.DummyMemsizer
-import prog8tests.asmgen.helpers.DummyStringEncoder
-import prog8tests.asmgen.helpers.ErrorReporterForTests
-import java.nio.file.Path
-
-
-@TestInstance(TestInstance.Lifecycle.PER_CLASS)
-class TestAsmGen6502 {
-
-    private fun createTestProgram(): Program {
-        /*
-main  {
-
-label_outside:
-    uword var_outside
-
-    sub start () {
-        uword localvar = 1234
-        uword tgt
-
-locallabel:
-        tgt = localvar
-        tgt = &locallabel
-        tgt = &var_outside
-        tgt = &label_outside
-        tgt = &main.start.localvar
-        tgt = &main.start.locallabel
-        tgt = &main.var_outside
-        tgt = &main.label_outside
-    }
-}
-
-         */
-        val varInSub = VarDecl(VarDeclType.VAR, DataType.UWORD, ZeropageWish.DONTCARE, null, "localvar", NumericLiteralValue.optimalInteger(1234, Position.DUMMY), false, false, false, Position.DUMMY)
-        val var2InSub = VarDecl(VarDeclType.VAR, DataType.UWORD, ZeropageWish.DONTCARE, null, "tgt", null, false, false, false, Position.DUMMY)
-        val labelInSub = Label("locallabel", Position.DUMMY)
-
-        val tgt = AssignTarget(IdentifierReference(listOf("tgt"), Position.DUMMY), null, null, Position.DUMMY)
-        val assign1 = Assignment(tgt, IdentifierReference(listOf("localvar"), Position.DUMMY), Position.DUMMY)
-        val assign2 = Assignment(tgt, AddressOf(IdentifierReference(listOf("locallabel"), Position.DUMMY), Position.DUMMY), Position.DUMMY)
-        val assign3 = Assignment(tgt, AddressOf(IdentifierReference(listOf("var_outside"), Position.DUMMY), Position.DUMMY), Position.DUMMY)
-        val assign4 = Assignment(tgt, AddressOf(IdentifierReference(listOf("label_outside"), Position.DUMMY), Position.DUMMY), Position.DUMMY)
-        val assign5 = Assignment(tgt, AddressOf(IdentifierReference(listOf("main","start","localvar"), Position.DUMMY), Position.DUMMY), Position.DUMMY)
-        val assign6 = Assignment(tgt, AddressOf(IdentifierReference(listOf("main","start","locallabel"), Position.DUMMY), Position.DUMMY), Position.DUMMY)
-        val assign7 = Assignment(tgt, AddressOf(IdentifierReference(listOf("main","var_outside"), Position.DUMMY), Position.DUMMY), Position.DUMMY)
-        val assign8 = Assignment(tgt, AddressOf(IdentifierReference(listOf("main","label_outside"), Position.DUMMY), Position.DUMMY), Position.DUMMY)
-
-        val statements = mutableListOf(varInSub, var2InSub, labelInSub, assign1, assign2, assign3, assign4, assign5, assign6, assign7, assign8)
-        val subroutine = Subroutine("start", mutableListOf(), emptyList(), emptyList(), emptyList(), emptySet(), null, false, false, statements, Position.DUMMY)
-        val labelInBlock = Label("label_outside", Position.DUMMY)
-        val varInBlock = VarDecl(VarDeclType.VAR, DataType.UWORD, ZeropageWish.DONTCARE, null, "var_outside", null, false, false, false, Position.DUMMY)
-        val block = Block("main", null, mutableListOf(labelInBlock, varInBlock, subroutine), false, Position.DUMMY)
-
-        val module = Module(mutableListOf(block), Position.DUMMY, SourceCode.Generated("test"))
-        val program = Program("test", DummyFunctions, DummyMemsizer, DummyStringEncoder)
-            .addModule(module)
-        module.linkIntoProgram(program)
-        return program
-    }
-
-    private fun createTestAsmGen(program: Program): AsmGen {
-        val errors = ErrorReporterForTests()
-        val options = CompilationOptions(OutputType.RAW, LauncherType.NONE, ZeropageType.FULL, emptyList(), false, true, C64Target)
-        val zp = C64MachineDefinition.C64Zeropage(options)
-        val asmgen = AsmGen(program, errors, zp, options, C64Target, Path.of(""))
-        return asmgen
-    }
-
-    @Test
-    fun testSymbolNameFromStrings() {
-        val program = createTestProgram()
-        val asmgen = createTestAsmGen(program)
-
-        assertThat(asmgen.asmSymbolName("name"), equalTo("name"))
-        assertThat(asmgen.asmSymbolName("<name>"), equalTo("prog8_name"))
-        assertThat(asmgen.asmSymbolName(RegisterOrPair.R15), equalTo("cx16.r15"))
-        assertThat(asmgen.asmSymbolName(listOf("a", "b", "name")), equalTo("a.b.name"))
-        assertThat(asmgen.asmVariableName("name"), equalTo("name"))
-        assertThat(asmgen.asmVariableName("<name>"), equalTo("prog8_name"))
-        assertThat(asmgen.asmVariableName(listOf("a", "b", "name")), equalTo("a.b.name"))
-    }
-
-    @Test
-    fun testSymbolNameFromVarIdentifier() {
-        val program = createTestProgram()
-        val asmgen = createTestAsmGen(program)
-        val sub = program.entrypoint
-
-        // local variable
-        val localvarIdent = sub.statements.filterIsInstance<Assignment>().first { it.value is IdentifierReference }.value as IdentifierReference
-        assertThat(asmgen.asmSymbolName(localvarIdent), equalTo("localvar"))
-        assertThat(asmgen.asmVariableName(localvarIdent), equalTo("localvar"))
-        val localvarIdentScoped = (sub.statements.filterIsInstance<Assignment>().first { (it.value as? AddressOf)?.identifier?.nameInSource==listOf("main", "start", "localvar") }.value as AddressOf).identifier
-        assertThat(asmgen.asmSymbolName(localvarIdentScoped), equalTo("main.start.localvar"))
-        assertThat(asmgen.asmVariableName(localvarIdentScoped), equalTo("main.start.localvar"))
-
-        // variable from outer scope (note that for Variables, no scoping prefix symbols are required,
-        //   because they're not outputted as locally scoped symbols for the assembler
-        val scopedVarIdent = (sub.statements.filterIsInstance<Assignment>().first { (it.value as? AddressOf)?.identifier?.nameInSource==listOf("var_outside") }.value as AddressOf).identifier
-        assertThat(asmgen.asmSymbolName(scopedVarIdent), equalTo("main.var_outside"))
-        assertThat(asmgen.asmVariableName(scopedVarIdent), equalTo("var_outside"))
-        val scopedVarIdentScoped = (sub.statements.filterIsInstance<Assignment>().first { (it.value as? AddressOf)?.identifier?.nameInSource==listOf("main", "var_outside") }.value as AddressOf).identifier
-        assertThat(asmgen.asmSymbolName(scopedVarIdentScoped), equalTo("main.var_outside"))
-        assertThat(asmgen.asmVariableName(scopedVarIdentScoped), equalTo("main.var_outside"))
-    }
-
-    @Test
-    fun testSymbolNameFromLabelIdentifier() {
-        val program = createTestProgram()
-        val asmgen = createTestAsmGen(program)
-        val sub = program.entrypoint
-
-        // local label
-        val localLabelIdent = (sub.statements.filterIsInstance<Assignment>().first { (it.value as? AddressOf)?.identifier?.nameInSource==listOf("locallabel") }.value as AddressOf).identifier
-        assertThat(asmgen.asmSymbolName(localLabelIdent), equalTo("_locallabel"))
-        assertThat("as a variable it uses different naming rules (no underscore prefix)", asmgen.asmVariableName(localLabelIdent), equalTo("locallabel"))
-        val localLabelIdentScoped = (sub.statements.filterIsInstance<Assignment>().first { (it.value as? AddressOf)?.identifier?.nameInSource==listOf("main","start","locallabel") }.value as AddressOf).identifier
-        assertThat(asmgen.asmSymbolName(localLabelIdentScoped), equalTo("main.start._locallabel"))
-        assertThat("as a variable it uses different naming rules (no underscore prefix)", asmgen.asmVariableName(localLabelIdentScoped), equalTo("main.start.locallabel"))
-
-        // label from outer scope needs sope prefixes because it is outputted as a locally scoped symbol for the assembler
-        val scopedLabelIdent = (sub.statements.filterIsInstance<Assignment>().first { (it.value as? AddressOf)?.identifier?.nameInSource==listOf("label_outside") }.value as AddressOf).identifier
-        assertThat(asmgen.asmSymbolName(scopedLabelIdent), equalTo("main._label_outside"))
-        assertThat("as a variable it uses different naming rules (no underscore prefix)", asmgen.asmVariableName(scopedLabelIdent), equalTo("label_outside"))
-        val scopedLabelIdentScoped = (sub.statements.filterIsInstance<Assignment>().first { (it.value as? AddressOf)?.identifier?.nameInSource==listOf("main","label_outside") }.value as AddressOf).identifier
-        assertThat(asmgen.asmSymbolName(scopedLabelIdentScoped), equalTo("main._label_outside"))
-        assertThat("as a variable it uses different naming rules (no underscore prefix)", asmgen.asmVariableName(scopedLabelIdentScoped), equalTo("main.label_outside"))
-    }
-}