move community note to start page

fix name redefinition check for multi-declarations
version 10.4.1
2026-10-22 20:02:27 +00:00 · 2024-09-20 20:12:33 +02:00 · 2024-09-20 19:55:32 +02:00 · 2024-09-20 18:43:08 +02:00 · 2024-09-20 17:33:00 +02:00 · 2024-09-20 17:28:55 +02:00
470 changed files with 58655 additions and 27635 deletions
@@ -0,0 +1,13 @@
+# These are supported funding model platforms
+
+#github: # Replace with up to 4 GitHub Sponsors-enabled usernames e.g., [user1, user2]
+#patreon: # Replace with a single Patreon username
+open_collective: # Replace with a single Open Collective username
+ko_fi: irmen
+#tidelift: # Replace with a single Tidelift platform-name/package-name e.g., npm/babel
+#community_bridge: # Replace with a single Community Bridge project-name e.g., cloud-foundry
+#liberapay: # Replace with a single Liberapay username
+#issuehunt: # Replace with a single IssueHunt username
+#otechie: # Replace with a single Otechie username
+#lfx_crowdfunding: # Replace with a single LFX Crowdfunding project-name e.g., cloud-foundry
+#custom: # Replace with up to 4 custom sponsorship URLs e.g., ['link1', 'link2']
@@ -10,22 +10,32 @@ jobs:

    steps:
      - name: Checkout code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4

-      - name: Install 64tass
-        run: sudo apt-get update -y && sudo apt-get install -y 64tass
+      - name: build and install recent 64tass
+        run: |
+          sudo apt-get install -y make build-essential
+          git clone --depth=1 https://github.com/irmen/64tass
+          cd 64tass
+          make -j4
+          sudo make install          

      - name: Set up JDK 11
-        uses: actions/setup-java@v2
+        uses: actions/setup-java@v4
        with:
          java-version: 11
-          distribution: adopt
+          distribution: temurin

      - name: Build and test with Gradle
-        run: ./gradlew build shadowJar --no-daemon
-
+        run: |
+          ./gradlew build shadowJar --no-daemon
+          sha256sum -b compiler/build/libs/*-all.jar > compiler/build/libs/hash.txt
+        
      - name: Create compiler shadowJar artifact
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
        with:
          name: prog8-compiler-jar-zipped
-          path: compiler/build/libs/*-all.jar
+          path: |
+            compiler/build/libs/*-all.jar
+            compiler/build/libs/hash.txt
+
@@ -15,6 +15,7 @@ out/
 parser/**/*.interp
 parser/**/*.tokens
 parser/**/*.java
+compiler/src/prog8/buildversion/*
 *.py[cod]
 *.egg
 *.egg-info
@@ -32,3 +33,4 @@ compiler/lib/
 /prog8compiler.jar
 sd*.img
 *.d64
+
@@ -9,6 +9,15 @@
    </inspection_tool>
    <inspection_tool class="IncompleteDestructuring" enabled="true" level="WARNING" enabled_by_default="true" />
    <inspection_tool class="PyInterpreterInspection" enabled="false" level="WARNING" enabled_by_default="false" />
+    <inspection_tool class="PyPackageRequirementsInspection" enabled="true" level="WARNING" enabled_by_default="true">
+      <option name="ignoredPackages">
+        <value>
+          <list size="1">
+            <item index="0" class="java.lang.String" itemvalue="sphinx_rtd_theme" />
+          </list>
+        </value>
+      </option>
+    </inspection_tool>
    <inspection_tool class="SpellCheckingInspection" enabled="true" level="TYPO" enabled_by_default="true">
      <option name="processCode" value="false" />
      <option name="processLiterals" value="true" />
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="Kotlin2JvmCompilerArguments">
+    <option name="jvmTarget" value="11" />
+  </component>
+  <component name="KotlinJpsPluginSettings">
+    <option name="version" value="1.9.24" />
+  </component>
+</project>
@@ -1,19 +1,23 @@
 <component name="libraryTable">
-  <library name="KotlinJavaRuntime">
+  <library name="KotlinJavaRuntime" type="repository">
+    <properties maven-id="org.jetbrains.kotlin:kotlin-stdlib-jdk8:2.0.20" />
    <CLASSES>
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-stdlib.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-reflect.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-test.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-stdlib-jdk7.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-stdlib-jdk8.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/2.0.20/kotlin-stdlib-jdk8-2.0.20.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/2.0.20/kotlin-stdlib-2.0.20.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/2.0.20/kotlin-stdlib-jdk7-2.0.20.jar!/" />
    </CLASSES>
-    <JAVADOC />
+    <JAVADOC>
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/2.0.20/kotlin-stdlib-jdk8-2.0.20-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/2.0.20/kotlin-stdlib-2.0.20-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/2.0.20/kotlin-stdlib-jdk7-2.0.20-javadoc.jar!/" />
+    </JAVADOC>
    <SOURCES>
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-stdlib-sources.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-reflect-sources.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-test-sources.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-stdlib-jdk7-sources.jar!/" />
-      <root url="jar://$KOTLIN_BUNDLED$/lib/kotlin-stdlib-jdk8-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/2.0.20/kotlin-stdlib-jdk8-2.0.20-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/2.0.20/kotlin-stdlib-2.0.20-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/2.0.20/kotlin-stdlib-jdk7-2.0.20-sources.jar!/" />
    </SOURCES>
  </library>
 </component>
@@ -1,17 +1,16 @@
 <component name="libraryTable">
  <library name="antlr.antlr4" type="repository">
-    <properties maven-id="org.antlr:antlr4:4.11.1">
+    <properties maven-id="org.antlr:antlr4:4.13.2">
      <exclude>
        <dependency maven-id="com.ibm.icu:icu4j" />
      </exclude>
    </properties>
    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4/4.11.1/antlr4-4.11.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4-runtime/4.11.1/antlr4-runtime-4.11.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4/4.13.2/antlr4-4.13.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4-runtime/4.13.2/antlr4-runtime-4.13.2.jar!/" />
      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr-runtime/3.5.3/antlr-runtime-3.5.3.jar!/" />
      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/ST4/4.3.4/ST4-4.3.4.jar!/" />
      <root url="jar://$MAVEN_REPOSITORY$/org/abego/treelayout/org.abego.treelayout.core/1.0.3/org.abego.treelayout.core-1.0.3.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/glassfish/javax.json/1.1.4/javax.json-1.1.4.jar!/" />
    </CLASSES>
    <JAVADOC />
    <SOURCES />
@@ -1,25 +0,0 @@
-<component name="libraryTable">
-  <library name="github.hypfvieh.dbus.java" type="repository">
-    <properties maven-id="com.github.hypfvieh:dbus-java:3.3.1" />
-    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/hypfvieh/dbus-java/3.3.1/dbus-java-3.3.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jnr-unixsocket/0.38.6/jnr-unixsocket-0.38.6.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jnr-ffi/2.2.2/jnr-ffi-2.2.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jffi/1.3.1/jffi-1.3.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jffi/1.3.1/jffi-1.3.1-native.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/ow2/asm/asm/9.1/asm-9.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/ow2/asm/asm-commons/9.1/asm-commons-9.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/ow2/asm/asm-analysis/9.1/asm-analysis-9.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/ow2/asm/asm-tree/9.1/asm-tree-9.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/ow2/asm/asm-util/9.1/asm-util-9.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jnr-a64asm/1.0.0/jnr-a64asm-1.0.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jnr-x86asm/1.0.2/jnr-x86asm-1.0.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jnr-constants/0.10.1/jnr-constants-0.10.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jnr-enxio/0.32.4/jnr-enxio-0.32.4.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jnr-posix/3.1.5/jnr-posix-3.1.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/slf4j/slf4j-api/1.7.30/slf4j-api-1.7.30.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>
@@ -1,10 +0,0 @@
-<component name="libraryTable">
-  <library name="glassfish.javax.json" type="repository">
-    <properties include-transitive-deps="false" maven-id="org.glassfish:javax.json:1.1.4" />
-    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/glassfish/javax.json/1.1.4/javax.json-1.1.4.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>
@@ -1,21 +1,18 @@
 <component name="libraryTable">
  <library name="io.kotest.assertions.core.jvm" type="repository">
-    <properties maven-id="io.kotest:kotest-assertions-core-jvm:5.3.2" />
+    <properties maven-id="io.kotest:kotest-assertions-core-jvm:5.9.1" />
    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.3.2/kotest-assertions-core-jvm-5.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.6.21/kotlin-stdlib-jdk8-1.6.21.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.6.21/kotlin-stdlib-1.6.21.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.9.1/kotest-assertions-core-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.9.1/kotest-assertions-shared-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/github/java-diff-utils/java-diff-utils/4.12/java-diff-utils-4.12.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.3.0/opentest4j-1.3.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.9.23/kotlin-stdlib-1.9.23.jar!/" />
      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.6.21/kotlin-stdlib-jdk7-1.6.21.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.3.2/kotest-assertions-shared-jvm-5.3.2.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-jdk8/1.6.1/kotlinx-coroutines-jdk8-1.6.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.6.21/kotlin-reflect-1.6.21.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.1/kotlinx-coroutines-core-jvm-1.6.1.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/5.3.2/kotest-common-jvm-5.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.3.2/kotest-assertions-api-jvm-5.3.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.8.0/kotlinx-coroutines-jdk8-1.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.9.23/kotlin-reflect-1.9.23.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.9.1/kotest-common-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.9.1/kotest-assertions-api-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.8.0/kotlinx-coroutines-core-jvm-1.8.0.jar!/" />
    </CLASSES>
    <JAVADOC />
    <SOURCES />
@@ -0,0 +1,23 @@
+<component name="libraryTable">
+  <library name="io.kotest.framework.datatest" type="repository">
+    <properties maven-id="io.kotest:kotest-framework-datatest:5.9.1" />
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-datatest/5.9.1/kotest-framework-datatest-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-datatest-jvm/5.9.1/kotest-framework-datatest-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.9.23/kotlin-stdlib-1.9.23.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.8.0/kotlinx-coroutines-core-jvm-1.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.9.1/kotest-common-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.9.23/kotlin-reflect-1.9.23.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-api-jvm/5.9.1/kotest-framework-api-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.9.1/kotest-assertions-shared-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.9.1/kotest-assertions-api-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.8.0/kotlinx-coroutines-jdk8-1.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/github/java-diff-utils/java-diff-utils/4.12/java-diff-utils-4.12.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.3.0/opentest4j-1.3.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-test-jvm/1.8.0/kotlinx-coroutines-test-jvm-1.8.0.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>
@@ -1,24 +0,0 @@
-<component name="libraryTable">
-  <library name="io.kotest.property.jvm" type="repository">
-    <properties maven-id="io.kotest:kotest-property-jvm:5.3.2" />
-    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-property-jvm/5.3.2/kotest-property-jvm-5.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/curious-odd-man/rgxgen/1.3/rgxgen-1.3.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.6.21/kotlin-stdlib-jdk8-1.6.21.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.6.21/kotlin-stdlib-1.6.21.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-jdk7/1.6.21/kotlin-stdlib-jdk7-1.6.21.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.3.2/kotest-common-jvm-5.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.3.2/kotest-assertions-shared-jvm-5.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.3.2/kotest-assertions-api-jvm-5.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.6.1/kotlinx-coroutines-jdk8-1.6.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.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/jetbrains/kotlin/kotlin-reflect/1.6.21/kotlin-reflect-1.6.21.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.1/kotlinx-coroutines-core-jvm-1.6.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.6.0/kotlin-stdlib-common-1.6.0.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>
@@ -1,51 +1,39 @@
 <component name="libraryTable">
  <library name="io.kotest.runner.junit5.jvm" type="repository">
-    <properties maven-id="io.kotest:kotest-runner-junit5-jvm:5.3.2" />
+    <properties maven-id="io.kotest:kotest-runner-junit5-jvm:5.9.1" />
    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-runner-junit5-jvm/5.3.2/kotest-runner-junit5-jvm-5.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-api-jvm/5.3.2/kotest-framework-api-jvm-5.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.3.2/kotest-assertions-shared-jvm-5.3.2.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/jetbrains/kotlinx/kotlinx-coroutines-test-jvm/1.6.1/kotlinx-coroutines-test-jvm-1.6.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.3.2/kotest-common-jvm-5.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-engine-jvm/5.3.2/kotest-framework-engine-jvm-5.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/github/classgraph/classgraph/4.8.146/classgraph-4.8.146.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-runner-junit5-jvm/5.9.1/kotest-runner-junit5-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-api-jvm/5.9.1/kotest-framework-api-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.9.1/kotest-assertions-shared-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/github/java-diff-utils/java-diff-utils/4.12/java-diff-utils-4.12.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-test-jvm/1.8.0/kotlinx-coroutines-test-jvm-1.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.9.1/kotest-common-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-engine-jvm/5.9.1/kotest-framework-engine-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/github/classgraph/classgraph/4.8.172/classgraph-4.8.172.jar!/" />
      <root url="jar://$MAVEN_REPOSITORY$/com/github/ajalt/mordant/1.2.1/mordant-1.2.1.jar!/" />
      <root url="jar://$MAVEN_REPOSITORY$/com/github/ajalt/colormath/1.2.0/colormath-1.2.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-debug/1.6.1/kotlinx-coroutines-debug-1.6.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.3.0/opentest4j-1.3.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-debug/1.8.0/kotlinx-coroutines-debug-1.8.0.jar!/" />
      <root url="jar://$MAVEN_REPOSITORY$/net/java/dev/jna/jna/5.9.0/jna-5.9.0.jar!/" />
      <root url="jar://$MAVEN_REPOSITORY$/net/java/dev/jna/jna-platform/5.9.0/jna-platform-5.9.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-discovery-jvm/5.3.2/kotest-framework-discovery-jvm-5.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.3.2/kotest-assertions-core-jvm-5.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.6.1/kotlinx-coroutines-jdk8-1.6.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.3.2/kotest-assertions-api-jvm-5.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-extensions-jvm/5.3.2/kotest-extensions-jvm-5.3.2.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/1.12.3/mockk-1.12.3.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-common/1.12.3/mockk-common-1.12.3.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-dsl/1.12.3/mockk-dsl-1.12.3.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-dsl-jvm/1.12.3/mockk-dsl-jvm-1.12.3.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-agent-jvm/1.12.3/mockk-agent-jvm-1.12.3.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-agent-api/1.12.3/mockk-agent-api-1.12.3.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-agent-common/1.12.3/mockk-agent-common-1.12.3.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/objenesis/objenesis/3.1/objenesis-3.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/net/bytebuddy/byte-buddy/1.12.6/byte-buddy-1.12.6.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/net/bytebuddy/byte-buddy-agent/1.12.6/byte-buddy-agent-1.12.6.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-concurrency-jvm/5.3.2/kotest-framework-concurrency-jvm-5.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.1/kotlinx-coroutines-core-jvm-1.6.1.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-jdk8/1.6.21/kotlin-stdlib-jdk8-1.6.21.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.6.21/kotlin-stdlib-1.6.21.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-jdk7/1.6.21/kotlin-stdlib-jdk7-1.6.21.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.6.21/kotlin-reflect-1.6.21.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/net/bytebuddy/byte-buddy/1.10.9/byte-buddy-1.10.9.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/net/bytebuddy/byte-buddy-agent/1.10.9/byte-buddy-agent-1.10.9.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-discovery-jvm/5.9.1/kotest-framework-discovery-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.9.1/kotest-assertions-core-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.8.0/kotlinx-coroutines-jdk8-1.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.9.1/kotest-assertions-api-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-extensions-jvm/5.9.1/kotest-extensions-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-concurrency-jvm/5.9.1/kotest-framework-concurrency-jvm-5.9.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.8.0/kotlinx-coroutines-core-jvm-1.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/23.0.0/annotations-23.0.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-engine/1.8.2/junit-platform-engine-1.8.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-commons/1.8.2/junit-platform-commons-1.8.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/apiguardian/apiguardian-api/1.1.2/apiguardian-api-1.1.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-suite-api/1.8.2/junit-platform-suite-api-1.8.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-launcher/1.8.2/junit-platform-launcher-1.8.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-api/5.8.2/junit-jupiter-api-5.8.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.9.23/kotlin-stdlib-1.9.23.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.9.23/kotlin-reflect-1.9.23.jar!/" />
    </CLASSES>
    <JAVADOC />
    <SOURCES />
@@ -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:0.3.4" />
+    <properties include-transitive-deps="false" maven-id="org.jetbrains.kotlinx:kotlinx-cli-jvm:0.3.6" />
    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-cli-jvm/0.3.4/kotlinx-cli-jvm-0.3.4.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-cli-jvm/0.3.6/kotlinx-cli-jvm-0.3.6.jar!/" />
    </CLASSES>
    <JAVADOC />
    <SOURCES />
@@ -1,13 +1,10 @@
 <component name="libraryTable">
  <library name="michael.bull.kotlin.result.jvm" type="repository">
-    <properties maven-id="com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.16" />
+    <properties maven-id="com.michael-bull.kotlin-result:kotlin-result-jvm:2.0.0" />
    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/com/michael-bull/kotlin-result/kotlin-result-jvm/1.1.16/kotlin-result-jvm-1.1.16.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.6.20/kotlin-stdlib-common-1.6.20.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.6.20/kotlin-stdlib-jdk8-1.6.20.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.6.20/kotlin-stdlib-1.6.20.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/com/michael-bull/kotlin-result/kotlin-result-jvm/2.0.0/kotlin-result-jvm-2.0.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.9.22/kotlin-stdlib-1.9.22.jar!/" />
      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.6.20/kotlin-stdlib-jdk7-1.6.20.jar!/" />
    </CLASSES>
    <JAVADOC />
    <SOURCES />
@@ -1,11 +0,0 @@
-<component name="libraryTable">
-  <library name="slf4j.simple" type="repository">
-    <properties maven-id="org.slf4j:slf4j-simple:1.7.36" />
-    <CLASSES>
-      <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 />
-  </library>
-</component>
@@ -1,17 +0,0 @@
-<component name="libraryTable">
-  <library name="takes" type="repository">
-    <properties maven-id="org.takes:takes:1.20" />
-    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/takes/takes/1.20/takes-1.20.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/cactoos/cactoos/0.50/cactoos-0.50.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/javax/xml/bind/jaxb-api/2.3.0/jaxb-api-2.3.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/slf4j/slf4j-api/1.7.25/slf4j-api-1.7.25.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/apache/commons/commons-text/1.4/commons-text-1.4.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/apache/commons/commons-lang3/3.7/commons-lang3-3.7.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/sun/xml/bind/jaxb-core/2.3.0/jaxb-core-2.3.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/sun/xml/bind/jaxb-impl/2.3.0/jaxb-impl-2.3.0.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>
@@ -16,10 +16,13 @@
      </list>
    </option>
  </component>
+  <component name="Black">
+    <option name="sdkName" value="Python 3.11" />
+  </component>
  <component name="FrameworkDetectionExcludesConfiguration">
    <type id="Python" />
  </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="true" project-jdk-name="openjdk-11" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="openjdk-17" project-jdk-type="JavaSDK">
    <output url="file://$PROJECT_DIR$/out" />
  </component>
 </project>
@@ -10,10 +10,8 @@
      <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://$PROJECT_DIR$/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://$PROJECT_DIR$/intermediate/intermediate.iml" filepath="$PROJECT_DIR$/intermediate/intermediate.iml" />
      <module fileurl="file://$PROJECT_DIR$/parser/parser.iml" filepath="$PROJECT_DIR$/parser/parser.iml" />
      <module fileurl="file://$PROJECT_DIR$/virtualmachine/virtualmachine.iml" filepath="$PROJECT_DIR$/virtualmachine/virtualmachine.iml" />
@@ -7,23 +7,21 @@ version: 2

 # Set the version of Python and other tools you might need
 build:
-  os: ubuntu-20.04
+  os: ubuntu-22.04
  tools:
-    python: "3.9"
-    # You can also specify other tool versions:
-    # nodejs: "16"
-    # rust: "1.55"
-    # golang: "1.17"
-
-# Build documentation in the docs/ directory with Sphinx
-sphinx:
-  configuration: docs/source/conf.py
-
-# If using Sphinx, optionally build your docs in additional formats such as PDF
-formats:
-  - pdf
+    python: "3.12"

 # Optionally declare the Python requirements required to build your docs
 python:
  install:
    - requirements: docs/requirements.txt
+
+# Build documentation in the docs/ directory with Sphinx
+sphinx:
+  configuration: docs/source/conf.py
+  fail_on_warning: true
+
+# If using Sphinx, optionally build your docs in additional formats such as PDF
+formats:
+  - pdf
+  - epub
@@ -0,0 +1,12 @@
+# super simple Makefile to lauch the main gradle targets to build and/or test the prog8 compiler
+
+.PHONY: all test
+
+all:
+	gradle installdist installshadowdist
+	@echo "compiler launch script can be found here: compiler/build/install/compiler-shadow/bin/p8compile"
+
+test:
+	gradle build
+	@echo "compiler launch script can be found here: compiler/build/install/compiler-shadow/bin/p8compile"
+
@@ -1,3 +1,4 @@
+[![ko-fi](https://ko-fi.com/img/githubbutton_sm.svg)](https://ko-fi.com/H2H6S0FFF)
 [![Documentation](https://readthedocs.org/projects/prog8/badge/?version=latest)](https://prog8.readthedocs.io/)

 Prog8 - Structured Programming Language for 8-bit 6502/65c02 microprocessors
@@ -9,11 +10,37 @@ This is a structured programming language for the 8-bit 6502/6510/65c02 micropro
 as used in many home computers from that era. It is a medium to low level programming language,
 which aims to provide many conveniences over raw assembly code (even when using a macro assembler).

+**Want to buy me a coffee or a pizza perhaps?**
+
+This project was created over the last couple of years by dedicating thousands of hours of my free time to it, to make it the best I possibly can.
+If you like Prog8, and think it's worth a nice cup of hot coffee or a delicious pizza, 
+you can help me out a little bit over at [ko-fi.com/irmen](https://ko-fi.com/irmen). 
+
+
 Documentation
 -------------
 Full documentation (syntax reference, how to use the language and the compiler, etc.) can be found at:
 https://prog8.readthedocs.io/

+How to get it/build it
+----------------------
+
+- Download the latest [official release](https://github.com/irmen/prog8/releases) from github.
+- Or, if you want/need a bleeding edge development version, you can:
+  - download a build artifact zipfile from a recent [github action build](https://github.com/irmen/prog8/actions).
+  - you can also compile it yourself from source. [Instructions here](https://prog8.readthedocs.io/en/latest/compiling.html).
+    Note that if you are not using *gradle* to build it, you might have to perform some manual
+    tasks once to make it compile fully. These are explained in the linked instructions. 
+- Alternatively, you can also install the compiler as a package on some linux distros:
+  - Arch (via AUR): [`prog8`](https://aur.archlinux.org/packages/prog8)
+
+Community
+---------
+Most of the development on Prog8 and the use of it is currently centered around 
+the [Commander X16](https://www.commanderx16.com/) retro computer. Their [discord server](https://discord.gg/nS2PqEC) contains a small channel
+dedicated to Prog8. Other than that, use the issue tracker on github.
+
+
 Software license
 ----------------
 GNU GPL 3.0 (see file LICENSE), with exception for generated code:
@@ -26,8 +53,9 @@ GNU GPL 3.0 (see file LICENSE), with exception for generated code:
 What does Prog8 provide?
 ------------------------

- reduction of source code length over raw assembly
- fast execution speed due to compilation to native assembly code. It's possible to write certain raster interrupt 'demoscene' effects purely in Prog8.
+- all advantages of a higher level language over having to write assembly code manually
+- programs run very fast because compilation to native machine code
+- code often is smaller and faster than equivalent C code compiled with CC65 or even LLVM-MOS
 - modularity, symbol scoping, subroutines
 - various data types other than just bytes (16-bit words, floats, strings)
 - floating point math is supported if the target system provides floating point library routines (C64 and Cx16 both do)
@@ -35,17 +63,18 @@ What does Prog8 provide?
 - automatic static variable allocations, automatic string and array variables and string sharing
 - subroutines with input parameters and result values
 - high-level program optimizations
+- no need for forward declarations
 - small program boilerplate/compilersupport overhead
 - programs can be run multiple times without reloading because of automatic variable (re)initializations.
 - conditional branches
 - ``when`` statement to provide a concise jump table alternative to if/elseif chains
 - ``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``
+- several specialized built-in functions such as ``lsb``, ``msb``, ``min``, ``max``, ``rol``, ``ror``
 - various powerful built-in libraries to do I/O, number conversions, graphics and more  
 - convenience abstractions for low level aspects such as ZeroPage handling, program startup, explicit memory addresses
 - inline assembly allows you to have full control when every cycle or byte matters
 - supports the sixteen 'virtual' 16-bit registers R0 - R15 from the Commander X16, and provides them also on the C64.
- encode strings and characters into petscii or screencodes as desired (C64/Cx16)
+- encode strings and characters into petscii or screencodes or even other encodings, as desired (C64/Cx16)

 *Rapid edit-compile-run-debug cycle:*

@@ -59,6 +88,8 @@ What does Prog8 provide?
 - "c64": Commodore-64  (6502 like CPU)
 - "c128": Commodore-128  (6502 like CPU - the Z80 cpu mode is not supported)
 - "cx16": [CommanderX16](https://www.commanderx16.com)  (65c02 CPU)
+- "pet32": Commodore PET (experimental)
+- "atari": Atari 8 bit such as 800XL (experimental)
 - If you only use standard kernal and prog8 library routines, it is possible to compile the *exact same program* for different machines (just change the compiler target flag)


@@ -76,7 +107,9 @@ IntelliJ IDEA with the Kotlin plugin).

 It's handy to have an emulator (or a real machine perhaps!) to run the programs on. The compiler assumes the presence
 of the [Vice emulator](http://vice-emu.sourceforge.net/)  for the C64 target,
-and the [x16emu emulator](https://github.com/commanderx16/x16-emulator) for the CommanderX16 target.
+and a recent emulator version (R42 or newer) for the CommanderX16, such as [x16emu](https://cx16forum.com/forum/viewforum.php?f=30) 
+(preferred, this is the official emulator. If required, source code is [here](https://github.com/X16Community/x16-emulator/)).
+There is also [Box16](https://github.com/indigodarkwolf/box16) which has powerful debugging features.

 **Syntax highlighting:** for a few different editors, syntax highlighting definition files are provided.
 Look in the [syntax-files](https://github.com/irmen/prog8/tree/master/syntax-files) directory in the github repository to find them.
@@ -89,14 +122,13 @@ This code calculates prime numbers using the Sieve of Eratosthenes algorithm::

    %import textio
    %zeropage basicsafe
-    
+
    main {
-    
-        ubyte[256] sieve
+        bool[256] sieve
        ubyte candidate_prime = 2       ; is increased in the loop
    
        sub start() {
-            sys.memset(sieve, 256, false)   ; clear the sieve
+            sys.memset(sieve, 256, 0)   ; clear the sieve
            txt.print("prime numbers up to 255:\n\n")
            ubyte amount=0
            repeat {
@@ -132,9 +164,6 @@ This code calculates prime numbers using the Sieve of Eratosthenes algorithm::
        }
    }

-
-
-
 when compiled an ran on a C-64 you'll get:

 ![c64 screen](docs/source/_static/primes_example.png)
@@ -6,9 +6,8 @@ plugins {
 }

 java {
-    toolchain {
-        languageVersion = JavaLanguageVersion.of(javaVersion)
-    }
+    targetCompatibility = JavaLanguageVersion.of(javaVersion)
+    sourceCompatibility = JavaLanguageVersion.of(javaVersion)
 }

 compileKotlin {
@@ -26,16 +25,16 @@ compileTestKotlin {
 dependencies {
    // should have no dependencies to other modules
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
-    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.16"
+    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:2.0.0"
 }

 sourceSets {
    main {
        java {
-            srcDirs = ["${project.projectDir}/src"]
+            srcDir "${project.projectDir}/src"
        }
        resources {
-            srcDirs = ["${project.projectDir}/res"]
+            srcDir "${project.projectDir}/res"
        }
    }
 }
@@ -15,14 +15,26 @@ class SymbolTable(astProgram: PtProgram) : StNode(astProgram.name, StNodeType.GL
     * This gives the fastest lookup possible (no need to traverse tree nodes)
     */

-    val flat: Map<String, StNode> by lazy {
+    private var cachedFlat: Map<String, StNode>? = null
+
+    val flat: Map<String, StNode> get()  {
+        if(cachedFlat!=null)
+            return cachedFlat!!
+
        val result = mutableMapOf<String, StNode>()
-        fun flatten(node: StNode) {
-            result[node.scopedName] = node
-            node.children.values.forEach { flatten(it) }
+        fun collect(node: StNode) {
+            for(child in node.children) {
+                result[child.value.scopedName] = child.value
+                collect(child.value)
+            }
        }
-        children.values.forEach { flatten(it) }
-        result
+        collect(this)
+        cachedFlat = result
+        return result
+    }
+
+    fun resetCachedFlat() {
+        cachedFlat = null
    }

    val allVariables: Collection<StStaticVariable> by lazy {
@@ -68,6 +80,15 @@ class SymbolTable(astProgram: PtProgram) : StNode(astProgram.name, StNodeType.GL
    }

    override fun lookup(scopedName: String) = flat[scopedName]
+
+    fun getLength(name: String): Int? {
+        return when(val node = flat[name]) {
+            is StMemVar -> node.length
+            is StMemorySlab -> node.size.toInt()
+            is StStaticVariable -> node.length
+            else -> null
+        }
+    }
 }


@@ -133,7 +154,7 @@ open class StNode(val name: String,
    }

    private val scopedNameList: List<String> by lazy {
-        if(type== StNodeType.GLOBAL)
+        if(type==StNodeType.GLOBAL)
            emptyList()
        else
            parent.scopedNameList + name
@@ -142,7 +163,7 @@ open class StNode(val name: String,
    private fun lookup(scopedName: List<String>): StNode? {
        // a scoped name refers to a name in another namespace, and always stars from the root.
        var node = this
-        while(node.type!= StNodeType.GLOBAL)
+        while(node.type!=StNodeType.GLOBAL)
            node = node.parent

        for(name in scopedName) {
@@ -173,14 +194,11 @@ class StStaticVariable(name: String,
                require(onetimeInitializationArrayValue.isEmpty() ||onetimeInitializationArrayValue.size==length)
        }
        if(onetimeInitializationNumericValue!=null) {
-            require(dt in NumericDatatypes)
-            require(onetimeInitializationNumericValue!=0.0) { "zero as init value should just remain uninitialized"}
+            require(dt in NumericDatatypes || dt==DataType.BOOL)
        }
        if(onetimeInitializationArrayValue!=null) {
            require(dt in ArrayDatatypes)
-            if(onetimeInitializationArrayValue.all { it.number!=null} ) {
-                require(onetimeInitializationArrayValue.any { it.number != 0.0 }) { "array of all zerors as init value should just remain uninitialized" }
-            }
+            require(length==onetimeInitializationArrayValue.size)
        }
        if(onetimeInitializationStringValue!=null) {
            require(dt == DataType.STR)
@@ -191,8 +209,7 @@ class StStaticVariable(name: String,


 class StConstant(name: String, val dt: DataType, val value: Double, astNode: PtNode) :
-    StNode(name, StNodeType.CONSTANT, astNode) {
-}
+    StNode(name, StNodeType.CONSTANT, astNode)


 class StMemVar(name: String,
@@ -201,6 +218,12 @@ class StMemVar(name: String,
               val length: Int?,             // for arrays: the number of elements, for strings: number of characters *including* the terminating 0-byte
               astNode: PtNode) :
    StNode(name, StNodeType.MEMVAR, astNode) {
+
+    init{
+        require(dt!=DataType.BOOL && dt!=DataType.ARRAY_BOOL)
+        if(dt in ArrayDatatypes || dt == DataType.STR)
+            requireNotNull(length)
+    }
 }

 class StMemorySlab(
@@ -209,16 +232,15 @@ class StMemorySlab(
    val align: UInt,
    astNode: PtNode
 ):
-    StNode(name, StNodeType.MEMORYSLAB, astNode) {
-}
+    StNode(name, StNodeType.MEMORYSLAB, astNode)
+

 class StSub(name: String, val parameters: List<StSubroutineParameter>, val returnType: DataType?, astNode: PtNode) :
-        StNode(name, StNodeType.SUBROUTINE, astNode) {
-}
+        StNode(name, StNodeType.SUBROUTINE, astNode)


 class StRomSub(name: String,
-               val address: UInt,
+               val address: UInt?,      // null in case of asmsub, specified in case of romsub
               val parameters: List<StRomSubParameter>,
               val returns: List<StRomSubParameter>,
               astNode: PtNode) :
@@ -228,7 +250,7 @@ class StRomSub(name: String,

 class StSubroutineParameter(val name: String, val type: DataType)
 class StRomSubParameter(val register: RegisterOrStatusflag, val type: DataType)
-class StArrayElement(val number: Double?, val addressOfSymbol: String?)
+class StArrayElement(val number: Double?, val addressOfSymbol: String?, val boolean: Boolean?)

 typealias StString = Pair<String, Encoding>
 typealias StArray = List<StArrayElement>
@@ -3,7 +3,8 @@ package prog8.code
 import prog8.code.ast.*
 import prog8.code.core.*
 import prog8.code.target.VMTarget
-import java.util.*
+import kotlin.collections.ArrayDeque
+

 class SymbolTableMaker(private val program: PtProgram, private val options: CompilationOptions) {
    fun make(): SymbolTable {
@@ -13,8 +14,8 @@ class SymbolTableMaker(private val program: PtProgram, private val options: Comp
            st.add(StNode(it.key, StNodeType.BUILTINFUNC, PtIdentifier(it.key, it.value.returnType ?: DataType.UNDEFINED, Position.DUMMY)))
        }

-        val scopestack = Stack<StNode>()
-        scopestack.push(st)
+        val scopestack = ArrayDeque<StNode>()
+        scopestack.add(st)
        program.children.forEach {
            addToSt(it, scopestack)
        }
@@ -26,28 +27,21 @@ class SymbolTableMaker(private val program: PtProgram, private val options: Comp
                PtMemMapped("P8ZP_SCRATCH_REG", DataType.UBYTE, options.compTarget.machine.zeropage.SCRATCH_REG, null, Position.DUMMY),
                PtMemMapped("P8ZP_SCRATCH_W1", DataType.UWORD, options.compTarget.machine.zeropage.SCRATCH_W1, null, Position.DUMMY),
                PtMemMapped("P8ZP_SCRATCH_W2", DataType.UWORD, options.compTarget.machine.zeropage.SCRATCH_W2, null, Position.DUMMY),
-                PtMemMapped("P8ESTACK_LO", DataType.ARRAY_UB, options.compTarget.machine.ESTACK_LO, 256u, Position.DUMMY),
-                PtMemMapped("P8ESTACK_HI", DataType.ARRAY_UB, options.compTarget.machine.ESTACK_HI, 256u, Position.DUMMY)
            ).forEach {
                it.parent = program
-                st.add(StMemVar(it.name, it.type, it.address, null, it))
+                st.add(StMemVar(it.name, it.type, it.address, it.arraySize?.toInt(), it))
            }
        }

        return st
    }

-    private fun addToSt(node: PtNode, scope: Stack<StNode>) {
+    private fun addToSt(node: PtNode, scope: ArrayDeque<StNode>) {
        val stNode = when(node) {
            is PtAsmSub -> {
-                if(node.address==null) {
-                    val params = node.parameters.map { StSubroutineParameter(it.second.name, it.second.type) }
-                    StSub(node.name, params, node.returns.singleOrNull()?.second, node)
-                } else {
-                    val parameters = node.parameters.map { StRomSubParameter(it.first, it.second.type) }
-                    val returns = node.returns.map { StRomSubParameter(it.first, it.second) }
-                    StRomSub(node.name, node.address, parameters, returns, node)
-                }
+                val parameters = node.parameters.map { StRomSubParameter(it.first, it.second.type) }
+                val returns = node.returns.map { StRomSubParameter(it.first, it.second) }
+                StRomSub(node.name, node.address, parameters, returns, node)
            }
            is PtBlock -> {
                StNode(node.name, StNodeType.BLOCK, node)
@@ -81,10 +75,9 @@ class SymbolTableMaker(private val program: PtProgram, private val options: Comp
                            numElements = value.value.length + 1   // include the terminating 0-byte
                        }
                        is PtArray -> {
-                            val array = makeInitialArray(value)
-                            initialArray = if(array.all { it.number==0.0 }) null else array            // all 0 as init value -> just uninitialized
+                            initialArray = makeInitialArray(value)
                            initialString = null
-                            numElements = array.size
+                            numElements = initialArray.size
                            require(node.arraySize?.toInt()==numElements)
                        }
                        else -> {
@@ -99,6 +92,9 @@ class SymbolTableMaker(private val program: PtProgram, private val options: Comp
                    initialString = null
                    numElements = node.arraySize?.toInt()
                }
+//                if(node.type in SplitWordArrayTypes) {
+//                    ... split array also add _lsb and _msb to symboltable?
+//                }
                StStaticVariable(node.name, node.type, initialNumeric, initialString, initialArray, numElements, node.zeropage, node)
            }
            is PtBuiltinFunctionCall -> {
@@ -109,7 +105,7 @@ class SymbolTableMaker(private val program: PtProgram, private val options: Comp
                    val size = (node.args[1] as PtNumber).number.toUInt()
                    val align = (node.args[2] as PtNumber).number.toUInt()
                    // don't add memory slabs in nested scope, just put them in the top level of the ST
-                    scope.firstElement().add(StMemorySlab("prog8_memoryslab_$slabname", size, align, node))
+                    scope.first().add(StMemorySlab("prog8_memoryslab_$slabname", size, align, node))
                }
                null
            }
@@ -117,22 +113,27 @@ class SymbolTableMaker(private val program: PtProgram, private val options: Comp
        }

        if(stNode!=null) {
-            scope.peek().add(stNode)
-            scope.push(stNode)
+            scope.last().add(stNode)
+            scope.add(stNode)
        }
        node.children.forEach {
            addToSt(it, scope)
        }
        if(stNode!=null)
-            scope.pop()
+            scope.removeLast()
    }

    private fun makeInitialArray(value: PtArray): List<StArrayElement> {
        return value.children.map {
            when(it) {
-                is PtAddressOf -> StArrayElement(null, it.identifier.name)
-                is PtIdentifier -> StArrayElement(null, it.name)
-                is PtNumber -> StArrayElement(it.number, null)
+                is PtAddressOf -> {
+                    if(it.isFromArrayElement)
+                        TODO("address-of array element $it in initial array value")
+                    StArrayElement(null, it.identifier.name, null)
+                }
+                is PtIdentifier -> StArrayElement(null, it.name, null)
+                is PtNumber -> StArrayElement(it.number, null, null)
+                is PtBool -> StArrayElement(null, null, it.value)
                else -> throw AssemblyError("invalid array element $it")
            }
        }
@@ -175,7 +176,7 @@ class SymbolTableMaker(private val program: PtProgram, private val options: Comp
 //                }
 //                VarDeclType.MEMORY -> {
 //                    val numElements =
-//                        if(decl.datatype in ArrayDatatypes)
+//                        if(decl.isArray)
 //                            decl.arraysize!!.constIndex()
 //                        else null
 //                    val astNode = PtVariable(decl.name, decl.datatype, null, null, decl.position)
@@ -31,22 +31,26 @@ sealed class PtNode(val position: Position) {
 }


-class PtNodeGroup : PtNode(Position.DUMMY)
+sealed interface IPtStatementContainer
+
+
+class PtNodeGroup : PtNode(Position.DUMMY), IPtStatementContainer


 sealed class PtNamedNode(var name: String, position: Position): PtNode(position) {
    // Note that as an exception, the 'name' is not read-only
    // but a var. This is to allow for cheap node renames.
-    val scopedName: String by lazy {
-        var namedParent: PtNode = this.parent
-        if(namedParent is PtProgram)
-            name
-        else {
-            while (namedParent !is PtNamedNode)
-                namedParent = namedParent.parent
-            namedParent.scopedName + "." + name
+    val scopedName: String
+        get() {
+            var namedParent: PtNode = this.parent
+            return if(namedParent is PtProgram)
+                name
+            else {
+                while (namedParent !is PtNamedNode)
+                    namedParent = namedParent.parent
+                namedParent.scopedName + "." + name
+            }
        }
-    }
 }


@@ -63,23 +67,31 @@ class PtProgram(
        children.asSequence().filterIsInstance<PtBlock>()

    fun entrypoint(): PtSub? =
-        allBlocks().firstOrNull { it.name == "main" }?.children?.firstOrNull { it is PtSub && it.name == "start" } as PtSub?
+        // returns the main.start subroutine if it exists
+        allBlocks().firstOrNull { it.name == "main" || it.name=="p8b_main" }
+            ?.children
+            ?.firstOrNull { it is PtSub && (it.name == "start" || it.name=="main.start" || it.name=="p8s_start" || it.name=="p8b_main.p8s_start") } as PtSub?
 }


 class PtBlock(name: String,
-              val address: UInt?,
              val library: Boolean,
-              val forceOutput: Boolean,
-              val alignment: BlockAlignment,
              val source: SourceCode,       // taken from the module the block is defined in.
+              val options: Options,
              position: Position
-) : PtNamedNode(name, position) {
+) : PtNamedNode(name, position), IPtStatementContainer {
    enum class BlockAlignment {
        NONE,
        WORD,
        PAGE
    }
+
+    class Options(val address: UInt? = null,
+                  val forceOutput: Boolean = false,
+                  val noSymbolPrefixing: Boolean = false,
+                  val veraFxMuls: Boolean = false,
+                  val ignoreUnused: Boolean = false,
+                  val alignment: BlockAlignment = BlockAlignment.NONE)
 }


@@ -1,16 +1,14 @@
 package prog8.code.ast

 import prog8.code.core.*
-import java.util.*
+import java.util.Objects
 import kotlin.math.abs
-import kotlin.math.round
+import kotlin.math.truncate


 sealed class PtExpression(val type: DataType, position: Position) : PtNode(position) {

    init {
-        if(type==DataType.BOOL)
-            throw IllegalArgumentException("bool should have become ubyte @$position")
        if(type==DataType.UNDEFINED) {
            @Suppress("LeakingThis")
            when(this) {
@@ -24,14 +22,43 @@ sealed class PtExpression(val type: DataType, position: Position) : PtNode(posit

    infix fun isSameAs(other: PtExpression): Boolean {
        return when(this) {
-            is PtAddressOf -> other is PtAddressOf && other.type==type && other.identifier isSameAs identifier
-            is PtArrayIndexer -> other is PtArrayIndexer && other.type==type && other.variable isSameAs variable && other.index isSameAs index
-            is PtBinaryExpression -> other is PtBinaryExpression && other.left isSameAs left && other.right isSameAs right
-            is PtContainmentCheck -> other is PtContainmentCheck && other.type==type && other.element isSameAs element && other.iterable isSameAs iterable
+            is PtAddressOf -> {
+                if(other !is PtAddressOf)
+                    return false
+                if (other.type!==type || !(other.identifier isSameAs identifier))
+                    return false
+                if(other.children.size!=children.size)
+                    return false
+                if(children.size==1)
+                    return true
+                return arrayIndexExpr!! isSameAs other.arrayIndexExpr!!
+            }
+            is PtArrayIndexer -> other is PtArrayIndexer && other.type==type && other.variable isSameAs variable && other.index isSameAs index && other.splitWords==splitWords
+            is PtBinaryExpression -> {
+                if(other !is PtBinaryExpression || other.operator!=operator)
+                    false
+                else if(operator in AssociativeOperators)
+                    (other.left isSameAs left && other.right isSameAs right) || (other.left isSameAs right && other.right isSameAs left)
+                else
+                    other.left isSameAs left && other.right isSameAs right
+            }
+            is PtContainmentCheck -> {
+                if(other !is PtContainmentCheck || other.type != type || !(other.needle isSameAs needle))
+                    false
+                else {
+                    if(haystackHeapVar!=null)
+                        other.haystackHeapVar!=null && other.haystackHeapVar!! isSameAs haystackHeapVar!!
+                    else if(haystackValues!=null)
+                        other.haystackValues!=null && other.haystackValues!! isSameAs haystackValues!!
+                    else
+                        false
+                }
+            }
            is PtIdentifier -> other is PtIdentifier && other.type==type && other.name==name
-            is PtMachineRegister -> other is PtMachineRegister && other.type==type && other.register==register
+            is PtIrRegister -> other is PtIrRegister && other.type==type && other.register==register
            is PtMemoryByte -> other is PtMemoryByte && other.address isSameAs address
            is PtNumber -> other is PtNumber && other.type==type && other.number==number
+            is PtBool -> other is PtBool && other.value==value
            is PtPrefix -> other is PtPrefix && other.type==type && other.operator==operator && other.value isSameAs value
            is PtRange -> other is PtRange && other.type==type && other.from==from && other.to==to && other.step==step
            is PtTypeCast -> other is PtTypeCast && other.type==type && other.value isSameAs value
@@ -48,13 +75,13 @@ sealed class PtExpression(val type: DataType, position: Position) : PtNode(posit
                this.name == target.identifier!!.name
            }
            target.array != null && this is PtArrayIndexer -> {
-                this.variable.name == target.array!!.variable.name && this.index isSameAs target.array!!.index
+                this.variable.name == target.array!!.variable.name && this.index isSameAs target.array!!.index && this.splitWords==target.array!!.splitWords
            }
            else -> false
        }
    }

-    fun asConstInteger(): Int? = (this as? PtNumber)?.number?.toInt()
+    fun asConstInteger(): Int? = (this as? PtNumber)?.number?.toInt() ?: (this as? PtBool)?.asInt()

    fun isSimple(): Boolean {
        return when(this) {
@@ -62,12 +89,18 @@ sealed class PtExpression(val type: DataType, position: Position) : PtNode(posit
            is PtArray -> true
            is PtArrayIndexer -> index is PtNumber || index is PtIdentifier
            is PtBinaryExpression -> false
-            is PtBuiltinFunctionCall -> name in arrayOf("msb", "lsb", "peek", "peekw", "mkword", "set_carry", "set_irqd", "clear_carry", "clear_irqd")
+            is PtBuiltinFunctionCall -> {
+                when (name) {
+                    in arrayOf("msb", "lsb", "mkword", "set_carry", "set_irqd", "clear_carry", "clear_irqd") -> this.args.all { it.isSimple() }
+                    else -> false
+                }
+            }
            is PtContainmentCheck -> false
            is PtFunctionCall -> false
            is PtIdentifier -> true
-            is PtMachineRegister -> true
+            is PtIrRegister -> true
            is PtMemoryByte -> address is PtNumber || address is PtIdentifier
+            is PtBool -> true
            is PtNumber -> true
            is PtPrefix -> value.isSimple()
            is PtRange -> true
@@ -94,6 +127,7 @@ sealed class PtExpression(val type: DataType, position: Position) : PtNode(posit
            is PtMachineRegister -> return withClonedChildrenFrom(this, PtMachineRegister(register, type, position))
            is PtMemoryByte -> return withClonedChildrenFrom(this, PtMemoryByte(position))
            is PtNumber -> return withClonedChildrenFrom(this, PtNumber(type, number, position))
+            is PtBool -> return withClonedChildrenFrom(this, PtBool(value, position))
            is PtPrefix -> return withClonedChildrenFrom(this, PtPrefix(operator, type, position))
            is PtRange -> return withClonedChildrenFrom(this, PtRange(type, position))
            is PtString -> return withClonedChildrenFrom(this, PtString(value, encoding, position))
@@ -105,7 +139,12 @@ sealed class PtExpression(val type: DataType, position: Position) : PtNode(posit

 class PtAddressOf(position: Position) : PtExpression(DataType.UWORD, position) {
    val identifier: PtIdentifier
-        get() = children.single() as PtIdentifier
+        get() = children[0] as PtIdentifier
+    val arrayIndexExpr: PtExpression?
+        get() = if(children.size==2) children[1] as PtExpression else null
+
+    val isFromArrayElement: Boolean
+        get() = children.size==2
 }


@@ -114,9 +153,11 @@ class PtArrayIndexer(elementType: DataType, position: Position): PtExpression(el
        get() = children[0] as PtIdentifier
    val index: PtExpression
        get() = children[1] as PtExpression
+    val splitWords: Boolean
+        get() = variable.type in SplitWordArrayTypes

    init {
-        require(elementType in NumericDatatypes)
+        require(elementType in NumericDatatypesWithBoolean)
    }
 }

@@ -150,19 +191,32 @@ class PtBuiltinFunctionCall(val name: String,


 class PtBinaryExpression(val operator: String, type: DataType, position: Position): PtExpression(type, position) {
-    // note: "and", "or", "xor" do not occur anymore as operators. They've been replaced int the ast by their bitwise versions &, |, ^.
    val left: PtExpression
        get() = children[0] as PtExpression
    val right: PtExpression
        get() = children[1] as PtExpression
+
+    init {
+        if(operator in ComparisonOperators + LogicalOperators)
+            require(type==DataType.BOOL)
+        else
+            require(type!=DataType.BOOL) { "no bool allowed for this operator $operator"}
+    }
 }


-class PtContainmentCheck(position: Position): PtExpression(DataType.UBYTE, position) {
-    val element: PtExpression
+class PtContainmentCheck(position: Position): PtExpression(DataType.BOOL, position) {
+    val needle: PtExpression
        get() = children[0] as PtExpression
-    val iterable: PtIdentifier
-        get() = children[1] as PtIdentifier
+    val haystackHeapVar: PtIdentifier?
+        get() = children[1] as? PtIdentifier
+    val haystackValues: PtArray?
+        get() = children[1] as? PtArray
+
+    companion object {
+        val MAX_SIZE_FOR_INLINE_CHECKS_BYTE = 5
+        val MAX_SIZE_FOR_INLINE_CHECKS_WORD = 4
+    }
 }


@@ -170,17 +224,18 @@ class PtFunctionCall(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 }
 }


-class PtIdentifier(val name: String, type: DataType, position: Position) : PtExpression(type, position)
+class PtIdentifier(val name: String, type: DataType, position: Position) : PtExpression(type, position) {
+    override fun toString(): String {
+        return "[PtIdentifier:$name $type $position]"
+    }
+
+    fun copy() = PtIdentifier(name, type, position)
+}


 class PtMemoryByte(position: Position) : PtExpression(DataType.UBYTE, position) {
@@ -189,6 +244,21 @@ class PtMemoryByte(position: Position) : PtExpression(DataType.UBYTE, position)
 }


+class PtBool(val value: Boolean, position: Position) : PtExpression(DataType.BOOL, position) {
+    override fun hashCode(): Int = Objects.hash(type, value)
+
+    override fun equals(other: Any?): Boolean {
+        if(other==null || other !is PtBool)
+            return false
+        return value==other.value
+    }
+
+    override fun toString() = "PtBool:$value"
+
+    fun asInt(): Int = if(value) 1 else 0
+}
+
+
 class PtNumber(type: DataType, val number: Double, position: Position) : PtExpression(type, position) {

    companion object {
@@ -198,23 +268,28 @@ class PtNumber(type: DataType, val number: Double, position: Position) : PtExpre

    init {
        if(type==DataType.BOOL)
-            throw IllegalArgumentException("bool should have become ubyte @$position")
+            throw IllegalArgumentException("use PtBool instead")
        if(type!=DataType.FLOAT) {
-            val rounded = round(number)
-            if (rounded != number)
-                throw IllegalArgumentException("refused rounding of float to avoid loss of precision @$position")
+            val trunc = truncate(number)
+            if (trunc != number)
+                throw IllegalArgumentException("refused truncating of float to avoid loss of precision @$position")
        }
    }

    override fun hashCode(): Int = Objects.hash(type, number)

    override fun equals(other: Any?): Boolean {
-        if(other==null || other !is PtNumber)
-            return false
-        return number==other.number
+        return if(other==null || other !is PtNumber)
+            false
+        else if(type!=DataType.BOOL && other.type!=DataType.BOOL)
+            number==other.number
+        else
+            type==other.type && number==other.number
    }

    operator fun compareTo(other: PtNumber): Int = number.compareTo(other.number)
+
+    override fun toString() = "PtNumber:$type:$number"
 }


@@ -223,8 +298,7 @@ class PtPrefix(val operator: String, type: DataType, position: Position): PtExpr
        get() = children.single() as PtExpression

    init {
-        // note: the "not" operator may no longer occur in the ast; not x should have been replaced with x==0
-        require(operator in setOf("+", "-", "~")) { "invalid prefix operator: $operator" }
+        require(operator in setOf("+", "-", "~", "not")) { "invalid prefix operator: $operator" }
    }
 }

@@ -240,6 +314,7 @@ class PtRange(type: DataType, position: Position) : PtExpression(type, position)
    fun toConstantIntegerRange(): IntProgression? {
        fun makeRange(fromVal: Int, toVal: Int, stepVal: Int): IntProgression {
            return when {
+                fromVal == toVal -> fromVal .. toVal
                fromVal <= toVal -> when {
                    stepVal <= 0 -> IntRange.EMPTY
                    stepVal == 1 -> fromVal..toVal
@@ -283,8 +358,8 @@ class PtTypeCast(type: DataType, position: Position) : PtExpression(type, positi


 // special node that isn't created from compiling user code, but used internally in the Intermediate Code
-class PtMachineRegister(val register: Int, type: DataType, position: Position) : PtExpression(type, position)
+class PtIrRegister(val register: Int, type: DataType, position: Position) : PtExpression(type, position)


-fun constValue(expr: PtExpression): Double? = if(expr is PtNumber) expr.number else null
-fun constIntValue(expr: PtExpression): Int? = if(expr is PtNumber) expr.number.toInt() else null
+fun constValue(expr: PtExpression): Double? = if(expr is PtNumber) expr.number else if(expr is PtBool) expr.asInt().toDouble() else null
+fun constIntValue(expr: PtExpression): Int? = if(expr is PtNumber) expr.number.toInt() else if(expr is PtBool) expr.asInt() else null
@@ -6,18 +6,23 @@ import prog8.code.core.*
 * Produces readable text from a [PtNode] (AST node, usually starting with PtProgram as root),
 * passing it as a String to the specified receiver function.
 */
-fun printAst(root: PtNode, output: (text: String) -> Unit) {
+fun printAst(root: PtNode, skipLibraries: Boolean, output: (text: String) -> Unit) {
    fun type(dt: DataType) = "!${dt.name.lowercase()}!"
    fun txt(node: PtNode): String {
        return when(node) {
-            is PtAssignTarget -> "<target>"
+            is PtAssignTarget -> if(node.void) "<void>" else "<target>"
            is PtAssignment -> "<assign>"
            is PtAugmentedAssign -> "<inplace-assign> ${node.operator}"
            is PtBreakpoint -> "%breakpoint"
            is PtConditionalBranch -> "if_${node.condition.name.lowercase()}"
-            is PtAddressOf -> "&"
+            is PtAddressOf -> {
+                if(node.isFromArrayElement)
+                    "& array-element"
+                else
+                    "&"
+            }
            is PtArray -> "array len=${node.children.size} ${type(node.type)}"
-            is PtArrayIndexer -> "<arrayindexer> ${type(node.type)}"
+            is PtArrayIndexer -> "<arrayindexer> ${type(node.type)} ${if(node.splitWords) "[splitwords]" else ""}"
            is PtBinaryExpression -> "<expr> ${node.operator} ${type(node.type)}"
            is PtBuiltinFunctionCall -> {
                val str = if(node.void) "void " else ""
@@ -29,12 +34,13 @@ fun printAst(root: PtNode, output: (text: String) -> Unit) {
                str + node.name + "()"
            }
            is PtIdentifier -> "${node.name} ${type(node.type)}"
-            is PtMachineRegister -> "VMREG#${node.register} ${type(node.type)}"
+            is PtIrRegister -> "IRREG#${node.register} ${type(node.type)}"
            is PtMemoryByte -> "@()"
            is PtNumber -> {
                val numstr = if(node.type == DataType.FLOAT) node.number.toString() else node.number.toHex()
                "$numstr ${type(node.type)}"
            }
+            is PtBool -> node.value.toString()
            is PtPrefix -> node.operator
            is PtRange -> "<range>"
            is PtString -> "\"${node.value.escape()}\""
@@ -53,15 +59,24 @@ fun printAst(root: PtNode, output: (text: String) -> Unit) {
                    "goto ${node.identifier.name}"
                else if(node.address!=null)
                    "goto ${node.address.toHex()}"
-                else if(node.generatedLabel!=null)
-                    "goto ${node.generatedLabel}"
                else
                    "???"
            }
            is PtAsmSub -> {
-                val params = if (node.parameters.isEmpty()) "" else "...TODO ${node.parameters.size} PARAMS..."
+                val params = node.parameters.joinToString(", ") {
+                    val register = it.first.registerOrPair
+                    val statusflag = it.first.statusflag
+                    "${it.second.type} ${it.second.name} @${register ?: statusflag}"
+                }
                val clobbers = if (node.clobbers.isEmpty()) "" else "clobbers ${node.clobbers}"
-                val returns = if (node.returns.isEmpty()) "" else (if (node.returns.size == 1) "-> ${node.returns[0].second.name.lowercase()}" else "-> ${node.returns.map { it.second.name.lowercase() }}")
+                val returns = if (node.returns.isEmpty()) "" else {
+                    "-> ${node.returns.joinToString(", ") {
+                            val register = it.first.registerOrPair
+                            val statusflag = it.first.statusflag
+                            "${it.second} @${register ?: statusflag}"
+                        }
+                    }"
+                }
                val str = if (node.inline) "inline " else ""
                if(node.address==null) {
                    str + "asmsub ${node.name}($params) $clobbers $returns"
@@ -70,12 +85,16 @@ fun printAst(root: PtNode, output: (text: String) -> Unit) {
                }
            }
            is PtBlock -> {
-                val addr = if(node.address==null) "" else "@${node.address.toHex()}"
-                val align = if(node.alignment==PtBlock.BlockAlignment.NONE) "" else "align=${node.alignment}"
+                val addr = if(node.options.address==null) "" else "@${node.options.address.toHex()}"
+                val align = if(node.options.alignment==PtBlock.BlockAlignment.NONE) "" else "align=${node.options.alignment}"
                "\nblock '${node.name}' $addr $align"
            }
            is PtConstant -> {
-                val value = if(node.type in IntegerDatatypes) node.value.toInt().toString() else node.value.toString()
+                val value = when(node.type) {
+                    DataType.BOOL -> if(node.value==0.0) "false" else "true"
+                    in IntegerDatatypes -> node.value.toInt().toString()
+                    else -> node.value.toString()
+                }
                "const ${node.type.name.lowercase()} ${node.name} = $value"
            }
            is PtLabel -> "${node.name}:"
@@ -89,20 +108,21 @@ fun printAst(root: PtNode, output: (text: String) -> Unit) {
                }
            }
            is PtSub -> {
-                val params = if (node.parameters.isEmpty()) "" else "...TODO ${node.parameters.size} PARAMS..."
+                val params = node.parameters.joinToString(", ") { "${it.type} ${it.name}" }
                var str = "sub ${node.name}($params) "
                if(node.returntype!=null)
                    str += "-> ${node.returntype.name.lowercase()}"
                str
            }
            is PtVariable -> {
+                val split = if(node.type in SplitWordArrayTypes) "@split" else ""
                val str = if(node.arraySize!=null) {
                    val eltType = ArrayToElementTypes.getValue(node.type)
-                    "${eltType.name.lowercase()}[${node.arraySize}] ${node.name}"
+                    "${eltType.name.lowercase()}[${node.arraySize}] $split ${node.name}"
                }
                else if(node.type in ArrayDatatypes) {
                    val eltType = ArrayToElementTypes.getValue(node.type)
-                    "${eltType.name.lowercase()}[] ${node.name}"
+                    "${eltType.name.lowercase()}[] $split ${node.name}"
                }
                else
                    "${node.type.name.lowercase()} ${node.name}"
@@ -111,9 +131,8 @@ fun printAst(root: PtNode, output: (text: String) -> Unit) {
                else
                    str
            }
-            is PtNodeGroup -> "<group>"
+            is PtNodeGroup -> if(node.children.isNotEmpty()) "<group>" else ""
            is PtNop -> "nop"
-            is PtPostIncrDecr -> "<post> ${node.operator}"
            is PtProgram -> "PROGRAM ${node.name}"
            is PtRepeatLoop -> "repeat"
            is PtReturn -> "return"
@@ -125,7 +144,6 @@ fun printAst(root: PtNode, output: (text: String) -> Unit) {
                else
                    "->"
            }
-            else -> throw InternalCompilerException("unrecognised ast node $node")
        }
    }

@@ -134,16 +152,22 @@ fun printAst(root: PtNode, output: (text: String) -> Unit) {
        root.children.forEach {
            walkAst(it) { node, depth ->
                val txt = txt(node)
-                if(txt.isNotEmpty())
-                    output("    ".repeat(depth) + txt(node))
+                val library = if(node is PtBlock) node.library else node.definingBlock()?.library==true
+                if(!library || !skipLibraries) {
+                    if (txt.isNotEmpty())
+                        output("    ".repeat(depth) + txt(node))
+                }
            }
        }
        println()
    } else {
        walkAst(root) { node, depth ->
            val txt = txt(node)
-            if(txt.isNotEmpty())
-                output("    ".repeat(depth) + txt(node))
+            val library = if(node is PtBlock) node.library else node.definingBlock()?.library==true
+            if(!library || !skipLibraries) {
+                if (txt.isNotEmpty())
+                    output("    ".repeat(depth) + txt(node))
+            }
        }
    }
 }
@@ -5,6 +5,7 @@ import prog8.code.core.*

 sealed interface IPtSubroutine {
    val name: String
+    val scopedName: String
 }

 class PtAsmSub(
@@ -23,13 +24,13 @@ class PtSub(
    val parameters: List<PtSubroutineParameter>,
    val returntype: DataType?,
    position: Position
-) : PtNamedNode(name, position), IPtSubroutine {
+) : PtNamedNode(name, position), IPtSubroutine, IPtStatementContainer {
    init {
        // params and return value should not be str
-        if(parameters.any{ it.type !in NumericDatatypes })
-            throw AssemblyError("non-numeric parameter")
-        if(returntype!=null && returntype !in NumericDatatypes)
-            throw AssemblyError("non-numeric returntype $returntype")
+        if(parameters.any{ it.type !in NumericDatatypes && it.type!=DataType.BOOL })
+            throw AssemblyError("non-numeric/non-bool parameter")
+        if(returntype!=null && returntype !in NumericDatatypes && returntype!=DataType.BOOL)
+            throw AssemblyError("non-numeric/non-bool returntype $returntype")
        parameters.forEach { it.parent=this }
    }
 }
@@ -38,28 +39,29 @@ class PtSub(
 class PtSubroutineParameter(name: String, val type: DataType, position: Position): PtNamedNode(name, position)


-class PtAssignment(position: Position) : PtNode(position) {
+sealed interface IPtAssignment {
+    val children: MutableList<PtNode>
    val target: PtAssignTarget
-        get() = children[0] as PtAssignTarget
-    val value: PtExpression
-        get() = children[1] as PtExpression
-}
-
-
-class PtAugmentedAssign(val operator: String, position: Position) : PtNode(position) {
-    val target: PtAssignTarget
-        get() = children[0] as PtAssignTarget
-    val value: PtExpression
-        get() = children[1] as PtExpression
-    init {
-        require(operator.endsWith('=') || operator in PrefixOperators) {
-            "invalid augmented assign operator $operator"
+        get() {
+            if(children.size==2)
+                return children[0] as PtAssignTarget
+            else if(children.size<2)
+                throw AssemblyError("incomplete node")
+            else
+                throw AssemblyError("no singular target")
        }
-    }
+    val value: PtExpression
+        get() = children.last() as PtExpression
+    val multiTarget: Boolean
+        get() = children.size>2
 }

+class PtAssignment(position: Position) : PtNode(position), IPtAssignment

-class PtAssignTarget(position: Position) : PtNode(position) {
+class PtAugmentedAssign(val operator: String, position: Position) : PtNode(position), IPtAssignment
+
+
+class PtAssignTarget(val void: Boolean, position: Position) : PtNode(position) {
    val identifier: PtIdentifier?
        get() = children.single() as? PtIdentifier
    val array: PtArrayIndexer?
@@ -77,7 +79,7 @@ class PtAssignTarget(position: Position) : PtNode(position) {
            }
        }

-    infix fun isSameAs(expression: PtExpression): Boolean = expression.isSameAs(this)
+    infix fun isSameAs(expression: PtExpression): Boolean = !void && expression.isSameAs(this)
 }


@@ -100,18 +102,19 @@ class PtForLoop(position: Position) : PtNode(position) {


 class PtIfElse(position: Position) : PtNode(position) {
-    val condition: PtBinaryExpression
-        get() = children[0] as PtBinaryExpression
+    val condition: PtExpression
+        get() = children[0] as PtExpression
    val ifScope: PtNodeGroup
        get() = children[1] as PtNodeGroup
    val elseScope: PtNodeGroup
        get() = children[2] as PtNodeGroup
+
+    fun hasElse(): Boolean = children.size==3 && elseScope.children.isNotEmpty()
 }


-class PtJump(val identifier: PtIdentifier?,
+class PtJump(val identifier: PtIdentifier?,     // note: even ad-hoc labels are wrapped as an Identifier to simplify code. Just use dummy type and position.
             val address: UInt?,
-             val generatedLabel: String?,
             position: Position) : PtNode(position) {
    init {
        identifier?.let {it.parent = this }
@@ -119,12 +122,6 @@ class PtJump(val identifier: PtIdentifier?,
 }


-class PtPostIncrDecr(val operator: String, position: Position) : PtNode(position) {
-    val target: PtAssignTarget
-        get() = children.single() as PtAssignTarget
-}
-
-
 class PtRepeatLoop(position: Position) : PtNode(position) {
    val count: PtExpression
        get() = children[0] as PtExpression
@@ -161,7 +158,11 @@ class PtVariable(name: String, override val type: DataType, val zeropage: Zeropa
 class PtConstant(name: String, override val type: DataType, val value: Double, position: Position) : PtNamedNode(name, position), IPtVariable


-class PtMemMapped(name: String, override val type: DataType, val address: UInt, val arraySize: UInt?, position: Position) : PtNamedNode(name, position), IPtVariable
+class PtMemMapped(name: String, override val type: DataType, val address: UInt, val arraySize: UInt?, position: Position) : PtNamedNode(name, position), IPtVariable {
+    init {
+        require(type!=DataType.BOOL && type!=DataType.ARRAY_BOOL)
+    }
+}


 class PtWhen(position: Position) : PtNode(position) {
@@ -68,43 +68,71 @@ class FSignature(val pure: Boolean,      // does it have side effects?
    }
 }

-
 val BuiltinFunctions: Map<String, FSignature> = mapOf(
    // this set of function have no return value and operate in-place:
+    "setlsb"    to FSignature(false, listOf(FParam("variable", arrayOf(DataType.WORD, DataType.UWORD)), FParam("value", arrayOf(DataType.BYTE, DataType.UBYTE))), null),
+    "setmsb"    to FSignature(false, listOf(FParam("variable", arrayOf(DataType.WORD, DataType.UWORD)), FParam("value", arrayOf(DataType.BYTE, DataType.UBYTE))), null),
    "rol"       to FSignature(false, listOf(FParam("item", arrayOf(DataType.UBYTE, DataType.UWORD))), null),
    "ror"       to FSignature(false, listOf(FParam("item", arrayOf(DataType.UBYTE, DataType.UWORD))), null),
    "rol2"      to FSignature(false, listOf(FParam("item", arrayOf(DataType.UBYTE, DataType.UWORD))), null),
    "ror2"      to FSignature(false, listOf(FParam("item", arrayOf(DataType.UBYTE, DataType.UWORD))), null),
-    "sort"      to FSignature(false, listOf(FParam("array", ArrayDatatypes)), null),
-    "reverse"   to FSignature(false, listOf(FParam("array", ArrayDatatypes)), null),
    // cmp returns a status in the carry flag, but not a proper return value
-    "cmp"       to FSignature(false, listOf(FParam("value1", IntegerDatatypesNoBool), FParam("value2", NumericDatatypesNoBool)), null),
-    "abs"       to FSignature(true, listOf(FParam("value", IntegerDatatypesNoBool)), DataType.UWORD),
+    "cmp"       to FSignature(false, listOf(FParam("value1", IntegerDatatypes), FParam("value2", NumericDatatypes)), null),
+    "prog8_lib_stringcompare"     to FSignature(true, listOf(FParam("str1", arrayOf(DataType.STR)), FParam("str2", arrayOf(DataType.STR))), DataType.BYTE),
+    "prog8_lib_arraycopy"         to FSignature(false, listOf(FParam("source", ArrayDatatypes), FParam("target", ArrayDatatypes)), null),
+    "prog8_lib_square_byte"       to FSignature(true, listOf(FParam("value", arrayOf(DataType.BYTE, DataType.UBYTE))), DataType.UBYTE),
+    "prog8_lib_square_word"       to FSignature(true, listOf(FParam("value", arrayOf(DataType.WORD, DataType.UWORD))), DataType.UWORD),
+    "prog8_ifelse_bittest_set"    to FSignature(true, listOf(FParam("variable", ByteDatatypes), FParam("bitnumber", arrayOf(DataType.UBYTE))), DataType.BOOL),
+    "prog8_ifelse_bittest_notset" to FSignature(true, listOf(FParam("variable", ByteDatatypes), FParam("bitnumber", arrayOf(DataType.UBYTE))), DataType.BOOL),
+    "abs"       to FSignature(true, listOf(FParam("value", NumericDatatypes)), null),
+    "abs__byte"  to FSignature(true, listOf(FParam("value", arrayOf(DataType.BYTE))), DataType.BYTE),
+    "abs__word"  to FSignature(true, listOf(FParam("value", arrayOf(DataType.WORD))), DataType.WORD),
+    "abs__float" to FSignature(true, listOf(FParam("value", arrayOf(DataType.FLOAT))), DataType.FLOAT),
    "len"       to FSignature(true, listOf(FParam("values", IterableDatatypes)), DataType.UWORD),
    // normal functions follow:
-    "sizeof"    to FSignature(true, listOf(FParam("object", DataType.values())), DataType.UBYTE),
-    "sgn"       to FSignature(true, listOf(FParam("value", NumericDatatypesNoBool)), DataType.BYTE),
-    "sqrt16"    to FSignature(true, listOf(FParam("value", arrayOf(DataType.UWORD))), DataType.UBYTE),
-    "any"       to FSignature(true, listOf(FParam("values", ArrayDatatypes)), DataType.UBYTE),
-    "all"       to FSignature(true, listOf(FParam("values", ArrayDatatypes)), DataType.UBYTE),
+    "sizeof"    to FSignature(true, listOf(FParam("object", DataType.entries.toTypedArray())), DataType.UBYTE),
+    "sgn"       to FSignature(true, listOf(FParam("value", NumericDatatypes)), DataType.BYTE),
+    "sqrt"        to FSignature(true, listOf(FParam("value", NumericDatatypes)), null),
+    "sqrt__ubyte" to FSignature(true, listOf(FParam("value", arrayOf(DataType.UBYTE))), DataType.UBYTE),
+    "sqrt__uword" to FSignature(true, listOf(FParam("value", arrayOf(DataType.UWORD))), DataType.UBYTE),
+    "sqrt__float" to FSignature(true, listOf(FParam("value", arrayOf(DataType.FLOAT))), DataType.FLOAT),
+    "divmod"           to FSignature(false, listOf(FParam("dividend", arrayOf(DataType.UBYTE, DataType.UWORD)), FParam("divisor", arrayOf(DataType.UBYTE, DataType.UWORD)), FParam("quotient", arrayOf(DataType.UBYTE, DataType.UWORD)), FParam("remainder", arrayOf(DataType.UBYTE, DataType.UWORD))), null),
+    "divmod__ubyte"    to FSignature(false, listOf(FParam("dividend", arrayOf(DataType.UBYTE)), FParam("divisor", arrayOf(DataType.UBYTE)), FParam("quotient", arrayOf(DataType.UBYTE)), FParam("remainder", arrayOf(DataType.UBYTE))), null),
+    "divmod__uword"    to FSignature(false, listOf(FParam("dividend", arrayOf(DataType.UWORD)), FParam("divisor", arrayOf(DataType.UWORD)), FParam("quotient", arrayOf(DataType.UWORD)), FParam("remainder", arrayOf(DataType.UWORD))), null),
    "lsb"       to FSignature(true, listOf(FParam("value", arrayOf(DataType.UWORD, DataType.WORD))), DataType.UBYTE),
    "msb"       to FSignature(true, listOf(FParam("value", arrayOf(DataType.UWORD, DataType.WORD))), DataType.UBYTE),
    "mkword"    to FSignature(true, listOf(FParam("msb", arrayOf(DataType.UBYTE)), FParam("lsb", arrayOf(DataType.UBYTE))), DataType.UWORD),
+    "clamp"     to FSignature(true, listOf(FParam("value", arrayOf(DataType.BYTE)), FParam("minimum", arrayOf(DataType.BYTE)), FParam("maximum", arrayOf(DataType.BYTE))), null),
+    "clamp__byte"  to FSignature(true, listOf(FParam("value", arrayOf(DataType.BYTE)), FParam("minimum", arrayOf(DataType.BYTE)), FParam("maximum", arrayOf(DataType.BYTE))), DataType.BYTE),
+    "clamp__ubyte" to FSignature(true, listOf(FParam("value", arrayOf(DataType.UBYTE)), FParam("minimum", arrayOf(DataType.UBYTE)), FParam("maximum", arrayOf(DataType.UBYTE))), DataType.UBYTE),
+    "clamp__word"  to FSignature(true, listOf(FParam("value", arrayOf(DataType.WORD)), FParam("minimum", arrayOf(DataType.WORD)), FParam("maximum", arrayOf(DataType.WORD))), DataType.WORD),
+    "clamp__uword" to FSignature(true, listOf(FParam("value", arrayOf(DataType.UWORD)), FParam("minimum", arrayOf(DataType.UWORD)), FParam("maximum", arrayOf(DataType.UWORD))), DataType.UWORD),
+    "min"        to FSignature(true, listOf(FParam("val1", arrayOf(DataType.BYTE)), FParam("val2", arrayOf(DataType.BYTE))), null),
+    "min__byte"  to FSignature(true, listOf(FParam("val1", arrayOf(DataType.BYTE)), FParam("val2", arrayOf(DataType.BYTE))), DataType.BYTE),
+    "min__ubyte" to FSignature(true, listOf(FParam("val1", arrayOf(DataType.UBYTE)), FParam("val2", arrayOf(DataType.UBYTE))), DataType.UBYTE),
+    "min__word"  to FSignature(true, listOf(FParam("val1", arrayOf(DataType.WORD)), FParam("val2", arrayOf(DataType.WORD))), DataType.WORD),
+    "min__uword" to FSignature(true, listOf(FParam("val1", arrayOf(DataType.UWORD)), FParam("val2", arrayOf(DataType.UWORD))), DataType.UWORD),
+    "max"        to FSignature(true, listOf(FParam("val1", arrayOf(DataType.BYTE)), FParam("val2", arrayOf(DataType.BYTE))), null),
+    "max__byte"  to FSignature(true, listOf(FParam("val1", arrayOf(DataType.BYTE)), FParam("val2", arrayOf(DataType.BYTE))), DataType.BYTE),
+    "max__ubyte" to FSignature(true, listOf(FParam("val1", arrayOf(DataType.UBYTE)), FParam("val2", arrayOf(DataType.UBYTE))), DataType.UBYTE),
+    "max__word"  to FSignature(true, listOf(FParam("val1", arrayOf(DataType.WORD)), FParam("val2", arrayOf(DataType.WORD))), DataType.WORD),
+    "max__uword" to FSignature(true, listOf(FParam("val1", arrayOf(DataType.UWORD)), FParam("val2", arrayOf(DataType.UWORD))), DataType.UWORD),
    "peek"      to FSignature(true, listOf(FParam("address", arrayOf(DataType.UWORD))), DataType.UBYTE),
    "peekw"     to FSignature(true, listOf(FParam("address", arrayOf(DataType.UWORD))), DataType.UWORD),
+    "peekf"     to FSignature(true, listOf(FParam("address", arrayOf(DataType.UWORD))), DataType.FLOAT),
    "poke"      to FSignature(false, listOf(FParam("address", arrayOf(DataType.UWORD)), FParam("value", arrayOf(DataType.UBYTE))), null),
-    "pokemon"   to FSignature(false, listOf(FParam("address", arrayOf(DataType.UWORD)), FParam("value", arrayOf(DataType.UBYTE))), null),
    "pokew"     to FSignature(false, listOf(FParam("address", arrayOf(DataType.UWORD)), FParam("value", arrayOf(DataType.UWORD))), null),
-    "pop"       to FSignature(false, listOf(FParam("target", ByteDatatypes)), null),
-    "popw"      to FSignature(false, listOf(FParam("target", WordDatatypes)), null),
-    "push"      to FSignature(false, listOf(FParam("value", ByteDatatypes)), null),
-    "pushw"     to FSignature(false, listOf(FParam("value", WordDatatypes)), null),
+    "pokef"     to FSignature(false, listOf(FParam("address", arrayOf(DataType.UWORD)), FParam("value", arrayOf(DataType.FLOAT))), null),
+    "pokemon"   to FSignature(false, listOf(FParam("address", arrayOf(DataType.UWORD)), FParam("value", arrayOf(DataType.UBYTE))), DataType.UBYTE),
    "rsave"     to FSignature(false, emptyList(), null),
-    "rsavex"    to FSignature(false, emptyList(), null),
    "rrestore"  to FSignature(false, emptyList(), null),
-    "rrestorex" to FSignature(false, emptyList(), null),
    "memory"    to FSignature(true, listOf(FParam("name", arrayOf(DataType.STR)), FParam("size", arrayOf(DataType.UWORD)), FParam("alignment", arrayOf(DataType.UWORD))), DataType.UWORD),
    "callfar"   to FSignature(false, listOf(FParam("bank", arrayOf(DataType.UBYTE)), FParam("address", arrayOf(DataType.UWORD)), FParam("arg", arrayOf(DataType.UWORD))), DataType.UWORD),
+    "call"      to FSignature(false, listOf(FParam("address", arrayOf(DataType.UWORD))), DataType.UWORD),
 )

-val InplaceModifyingBuiltinFunctions = setOf("rol", "ror", "rol2", "ror2", "sort", "reverse")
+val InplaceModifyingBuiltinFunctions = setOf(
+    "setlsb", "setmsb",
+    "rol", "ror", "rol2", "ror2",
+    "divmod", "divmod__ubyte", "divmod__uword"
+)
@@ -8,23 +8,34 @@ class CompilationOptions(val output: OutputType,
                         val launcher: CbmPrgLauncherType,
                         val zeropage: ZeropageType,
                         val zpReserved: List<UIntRange>,
+                         val zpAllowed: List<UIntRange>,
                         val floats: Boolean,
                         val noSysInit: Boolean,
                         val compTarget: ICompilationTarget,
                         // these are set later, based on command line arguments or options in the source code:
                         var loadAddress: UInt,
-                         var slowCodegenWarnings: Boolean = false,
+                         var warnSymbolShadowing: Boolean = false,
                         var optimize: Boolean = false,
-                         var optimizeFloatExpressions: Boolean = false,
                         var asmQuiet: Boolean = false,
                         var asmListfile: Boolean = false,
+                         var includeSourcelines: Boolean = false,
+                         var dumpVariables: Boolean = false,
+                         var dumpSymbols: Boolean = false,
                         var experimentalCodegen: Boolean = false,
-                         var varsHigh: Boolean = false,
-                         var evalStackBaseAddress: UInt? = null,
+                         var varsHighBank: Int? = null,
+                         var varsGolden: Boolean = false,
+                         var slabsHighBank: Int? = null,
+                         var slabsGolden: Boolean = false,
+                         var splitWordArrays: Boolean = false,
+                         var breakpointCpuInstruction: String? = null,
                         var outputDir: Path = Path(""),
                         var symbolDefs: Map<String, String> = emptyMap()
 ) {
    init {
        compTarget.machine.initializeMemoryAreas(this)
    }
+
+    companion object {
+        val AllZeropageAllowed: List<UIntRange> = listOf(0u..255u)
+    }
 }
@@ -1,6 +1,11 @@
 package prog8.code.core

 import kotlin.math.abs
+import kotlin.math.pow
+
+val powersOfTwoFloat = (0..16).map { (2.0).pow(it) }.toTypedArray()
+val negativePowersOfTwoFloat = powersOfTwoFloat.map { -it }.toTypedArray()
+val powersOfTwoInt = (0..16).map { 2.0.pow(it).toInt() }.toTypedArray()

 fun Number.toHex(): String {
    //  0..15 -> "0".."15"
@@ -58,6 +63,7 @@ fun String.unescape(): String {
                '\\' -> '\\'
                'n' -> '\n'
                'r' -> '\r'
+                't' -> '\t'
                '"' -> '"'
                '\'' -> '\''
                'u' -> {
@@ -1,17 +1,20 @@
 package prog8.code.core

 enum class DataType {
-    UBYTE,              // pass by value
-    BYTE,               // pass by value
-    UWORD,              // pass by value
-    WORD,               // pass by value
-    FLOAT,              // pass by value
-    BOOL,               // pass by value
+    UBYTE,              // pass by value            8 bits unsigned
+    BYTE,               // pass by value            8 bits signed
+    UWORD,              // pass by value            16 bits unsigned
+    WORD,               // pass by value            16 bits signed
+    LONG,               // pass by value            32 bits signed
+    FLOAT,              // pass by value            machine dependent
+    BOOL,               // pass by value            bit 0 of a 8 bit byte
    STR,                // pass by reference
    ARRAY_UB,           // pass by reference
    ARRAY_B,            // pass by reference
    ARRAY_UW,           // pass by reference
+    ARRAY_UW_SPLIT,     // pass by reference, lo/hi byte split
    ARRAY_W,            // pass by reference
+    ARRAY_W_SPLIT,      // pass by reference, lo/hi byte split
    ARRAY_F,            // pass by reference
    ARRAY_BOOL,         // pass by reference
    UNDEFINED;
@@ -21,11 +24,12 @@ enum class DataType {
     */
    infix fun isAssignableTo(targetType: DataType) =
        when(this) {
-            BOOL -> targetType.oneOf(BOOL, BYTE, UBYTE, WORD, UWORD, FLOAT)
-            UBYTE -> targetType.oneOf(UBYTE, WORD, UWORD, FLOAT, BOOL)
-            BYTE -> targetType.oneOf(BYTE, WORD, FLOAT)
-            UWORD -> targetType.oneOf(UWORD, FLOAT)
-            WORD -> targetType.oneOf(WORD, FLOAT)
+            BOOL -> targetType == BOOL
+            UBYTE -> targetType.oneOf(UBYTE, WORD, UWORD, LONG, FLOAT)
+            BYTE -> targetType.oneOf(BYTE, WORD, LONG, FLOAT)
+            UWORD -> targetType.oneOf(UWORD, LONG, FLOAT)
+            WORD -> targetType.oneOf(WORD, LONG, FLOAT)
+            LONG -> targetType.oneOf(LONG, FLOAT)
            FLOAT -> targetType.oneOf(FLOAT)
            STR -> targetType.oneOf(STR, UWORD)
            in ArrayDatatypes -> targetType == this
@@ -37,16 +41,17 @@ enum class DataType {
    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
+            this in ByteDatatypesWithBoolean -> false
+            this in WordDatatypes -> other in ByteDatatypesWithBoolean
+            this == LONG -> other in ByteDatatypesWithBoolean+WordDatatypes
+            this == STR && other == UWORD || this == UWORD && other == STR -> false
            else -> true
        }

    infix fun equalsSize(other: DataType) =
        when {
            this == other -> true
-            this in ByteDatatypes -> other in ByteDatatypes
+            this in ByteDatatypesWithBoolean -> other in ByteDatatypesWithBoolean
            this in WordDatatypes -> other in WordDatatypes
            this== STR && other== UWORD || this== UWORD && other== STR -> true
            else -> false
@@ -73,7 +78,14 @@ enum class RegisterOrPair {
    R8, R9, R10, R11, R12, R13, R14, R15;

    companion object {
-        val names by lazy { values().map { it.toString()} }
+        val names by lazy { entries.map { it.toString()} }
+        fun fromCpuRegister(cpu: CpuRegister): RegisterOrPair {
+            return when(cpu) {
+                CpuRegister.A -> A
+                CpuRegister.X -> X
+                CpuRegister.Y -> Y
+            }
+        }
    }

    fun asCpuRegister(): CpuRegister = when(this) {
@@ -92,7 +104,7 @@ enum class Statusflag {
    Pn;     // don't use

    companion object {
-        val names by lazy { values().map { it.toString()} }
+        val names by lazy { entries.map { it.toString()} }
    }
 }

@@ -108,26 +120,29 @@ enum class BranchCondition {
    PL,     // PL == POS
    POS,
    VS,
-    VC,
+    VC
 }


-val ByteDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE, DataType.BOOL)
+val ByteDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE)
+val ByteDatatypesWithBoolean = ByteDatatypes + DataType.BOOL
 val WordDatatypes = arrayOf(DataType.UWORD, DataType.WORD)
-val IntegerDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD, DataType.BOOL)
-val IntegerDatatypesNoBool = arrayOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD)
-val NumericDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD, DataType.FLOAT, DataType.BOOL)
-val NumericDatatypesNoBool = 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, DataType.ARRAY_BOOL)
+val IntegerDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD, DataType.LONG)
+val IntegerDatatypesWithBoolean = IntegerDatatypes + DataType.BOOL
+val NumericDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD, DataType.LONG, DataType.FLOAT)
+val NumericDatatypesWithBoolean = NumericDatatypes + DataType.BOOL
+val SignedDatatypes =  arrayOf(DataType.BYTE, DataType.WORD, DataType.LONG, DataType.FLOAT)
+val ArrayDatatypes = arrayOf(DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_UW_SPLIT, DataType.ARRAY_W, DataType.ARRAY_W_SPLIT, DataType.ARRAY_F, DataType.ARRAY_BOOL)
 val StringlyDatatypes = arrayOf(DataType.STR, DataType.ARRAY_UB, DataType.ARRAY_B, DataType.UWORD)
+val SplitWordArrayTypes = arrayOf(DataType.ARRAY_UW_SPLIT, DataType.ARRAY_W_SPLIT)
 val IterableDatatypes = arrayOf(
    DataType.STR,
    DataType.ARRAY_UB, DataType.ARRAY_B,
    DataType.ARRAY_UW, DataType.ARRAY_W,
+    DataType.ARRAY_UW_SPLIT, DataType.ARRAY_W_SPLIT,
    DataType.ARRAY_F, DataType.ARRAY_BOOL
 )
-val PassByValueDatatypes = NumericDatatypes
+val PassByValueDatatypes = NumericDatatypesWithBoolean
 val PassByReferenceDatatypes = IterableDatatypes
 val ArrayToElementTypes = mapOf(
    DataType.STR to DataType.UBYTE,
@@ -135,6 +150,8 @@ val ArrayToElementTypes = mapOf(
    DataType.ARRAY_UB to DataType.UBYTE,
    DataType.ARRAY_W to DataType.WORD,
    DataType.ARRAY_UW to DataType.UWORD,
+    DataType.ARRAY_W_SPLIT to DataType.WORD,
+    DataType.ARRAY_UW_SPLIT to DataType.UWORD,
    DataType.ARRAY_F to DataType.FLOAT,
    DataType.ARRAY_BOOL to DataType.BOOL
 )
@@ -144,8 +161,10 @@ val ElementToArrayTypes = mapOf(
    DataType.WORD to DataType.ARRAY_W,
    DataType.UWORD to DataType.ARRAY_UW,
    DataType.FLOAT to DataType.ARRAY_F,
-    DataType.BOOL to DataType.ARRAY_BOOL
+    DataType.BOOL to DataType.ARRAY_BOOL,
+    DataType.STR to DataType.ARRAY_UW          // array of str is just an array of pointers
 )
+
 val Cx16VirtualRegisters = arrayOf(
    RegisterOrPair.R0, RegisterOrPair.R1, RegisterOrPair.R2, RegisterOrPair.R3,
    RegisterOrPair.R4, RegisterOrPair.R5, RegisterOrPair.R6, RegisterOrPair.R7,
@@ -153,6 +172,10 @@ val Cx16VirtualRegisters = arrayOf(
    RegisterOrPair.R12, RegisterOrPair.R13, RegisterOrPair.R14, RegisterOrPair.R15
 )

+val CpuRegisters = setOf(
+    RegisterOrPair.A, RegisterOrPair.X, RegisterOrPair.Y,
+    RegisterOrPair.AX, RegisterOrPair.AY, RegisterOrPair.XY
+)


 enum class OutputType {
@@ -13,7 +13,5 @@ interface ICodeGeneratorBackend {

 interface IAssemblyProgram {
    val name: String
-    fun assemble(options: CompilationOptions): Boolean
+    fun assemble(options: CompilationOptions, errors: IErrorReporter): Boolean
 }
-
-fun viceMonListName(baseFilename: String) = "$baseFilename.vice-mon-list"
@@ -3,8 +3,6 @@ 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: Iterable<UByte>, encoding: Encoding): String
@@ -3,10 +3,14 @@ package prog8.code.core
 interface IErrorReporter {
    fun err(msg: String, position: Position)
    fun warn(msg: String, position: Position)
+    fun info(msg: String, position: Position)
+    fun undefined(symbol: List<String>, position: Position)
    fun noErrors(): Boolean
    fun report()
-    fun finalizeNumErrors(numErrors: Int, numWarnings: Int) {
+    fun finalizeNumErrors(numErrors: Int, numWarnings: Int, numInfos: Int) {
        if(numErrors>0)
-            throw ErrorsReportedException("There are $numErrors errors and $numWarnings warnings.")
+            throw ErrorsReportedException("There are $numErrors errors, $numWarnings warnings, and $numInfos infos.")
    }
+
+    fun noErrorForLine(position: Position): Boolean
 }
@@ -13,11 +13,11 @@ interface IMachineDefinition {
    val FLOAT_MAX_NEGATIVE: Double
    val FLOAT_MAX_POSITIVE: Double
    val FLOAT_MEM_SIZE: Int
-    var ESTACK_LO: UInt
-    var ESTACK_HI: UInt
    val PROGRAM_LOAD_ADDRESS : UInt
    val BSSHIGHRAM_START: UInt
    val BSSHIGHRAM_END: UInt
+    val BSSGOLDENRAM_START: UInt
+    val BSSGOLDENRAM_END: UInt

    val cpu: CpuType
    var zeropage: Zeropage
@@ -26,14 +26,9 @@ interface IMachineDefinition {
    fun initializeMemoryAreas(compilerOptions: CompilationOptions)
    fun getFloatAsmBytes(num: Number): String

-    fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String>
+    fun convertFloatToBytes(num: Double): List<UByte>
+    fun convertBytesToFloat(bytes: List<UByte>): Double
+
    fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path)
    fun isIOAddress(address: UInt): Boolean
-    fun overrideEvalStack(evalStackBaseAddress: UInt) {
-        require(evalStackBaseAddress and 255u == 0u)
-        ESTACK_LO = evalStackBaseAddress
-        ESTACK_HI = evalStackBaseAddress + 256u
-        require(ESTACK_LO !in golden.region && ESTACK_HI !in golden.region) { "user-set ESTACK can't be in GOLDEN ram" }
-    }
-
 }
@@ -5,10 +5,16 @@ enum class Encoding(val prefix: String) {
    PETSCII("petscii"),         // c64/c128/cx16
    SCREENCODES("sc"),          // c64/c128/cx16
    ATASCII("atascii"),         // atari
-    ISO("iso")                  // cx16
+    ISO("iso"),                 // cx16  (iso-8859-15)
+    ISO5("iso5"),               // cx16  (iso-8859-5, cyrillic)
+    ISO16("iso16"),             // cx16  (iso-8859-16, eastern european)
+    CP437("cp437"),             // cx16  (ibm pc, codepage 437)
+    KATAKANA("kata")                 // cx16  (katakana)
 }

 interface IStringEncoding {
+    val defaultEncoding: Encoding
+
    fun encodeString(str: String, encoding: Encoding): List<UByte>
    fun decodeString(bytes: Iterable<UByte>, encoding: Encoding): String
 }
@@ -42,6 +42,13 @@ abstract class Zeropage(options: CompilationOptions): MemoryAllocator(options) {
        }
    }

+    fun retainAllowed() {
+        synchronized(this) {
+            for(allowed in options.zpAllowed)
+                free.retainAll { it in allowed }
+        }
+    }
+
    fun availableBytes() = if(options.zeropage== ZeropageType.DONTUSE) 0 else free.size
    fun hasByteAvailable() = if(options.zeropage== ZeropageType.DONTUSE) false else free.isNotEmpty()
    fun hasWordAvailable(): Boolean {
@@ -64,7 +71,7 @@ abstract class Zeropage(options: CompilationOptions): MemoryAllocator(options) {

        val size: Int =
                when (datatype) {
-                    in IntegerDatatypes -> options.compTarget.memorySize(datatype)
+                    in IntegerDatatypesWithBoolean -> options.compTarget.memorySize(datatype)
                    DataType.STR, in ArrayDatatypes  -> {
                        val memsize = options.compTarget.memorySize(datatype, numElements!!)
                        if(position!=null)
@@ -112,7 +119,7 @@ abstract class Zeropage(options: CompilationOptions): MemoryAllocator(options) {
        free.removeAll(address until address+size.toUInt())
        if(name.isNotEmpty()) {
            allocatedVariables[name] = when(datatype) {
-                in NumericDatatypes -> VarAllocation(address, datatype, size)        // numerical variables in zeropage never have an initial value here because they are set in separate initializer assignments
+                in NumericDatatypes, DataType.BOOL -> VarAllocation(address, datatype, size)        // numerical variables in zeropage never have an initial value here because they are set in separate initializer assignments
                DataType.STR -> VarAllocation(address, datatype, size)
                in ArrayDatatypes -> VarAllocation(address, datatype, size)
                else -> throw AssemblyError("invalid dt")
@@ -131,6 +138,7 @@ abstract class Zeropage(options: CompilationOptions): MemoryAllocator(options) {
 }


+// TODO: this class is not yet used
 class GoldenRam(options: CompilationOptions, val region: UIntRange): MemoryAllocator(options) {
    private var nextLocation: UInt = region.first

@@ -143,7 +151,7 @@ class GoldenRam(options: CompilationOptions, val region: UIntRange): MemoryAlloc

        val size: Int =
            when (datatype) {
-                in IntegerDatatypes -> options.compTarget.memorySize(datatype)
+                in IntegerDatatypesWithBoolean -> options.compTarget.memorySize(datatype)
                DataType.STR, in ArrayDatatypes  -> {
                    options.compTarget.memorySize(datatype, numElements!!)
                }
@@ -1,12 +1,10 @@
 package prog8.code.core

-val AssociativeOperators = setOf("+", "*", "&", "|", "^", "==", "!=")
+val AssociativeOperators = setOf("+", "*", "&", "|", "^", "==", "!=", "xor")       // note: and,or are no longer associative because of Shortcircuit/McCarthy evaluation
 val ComparisonOperators = setOf("==", "!=", "<", ">", "<=", ">=")
-val LogicalOperators = setOf("and", "or", "xor", "not")
-val AugmentAssignmentOperators = setOf("+", "-", "/", "*", "&", "|", "^", "<<", ">>", "%", "and", "or", "xor")
+val LogicalOperators = setOf("and", "or", "xor", "not", "in")
 val BitwiseOperators = setOf("&", "|", "^", "~")
 val PrefixOperators = setOf("+", "-", "~", "not")
-// val InvalidOperatorsForBoolean = setOf("+", "-", "*", "/", "%", "<<", ">>") + BitwiseOperators

 fun invertedComparisonOperator(operator: String) =
    when (operator) {
@@ -1,5 +1,6 @@
 package prog8.code.core

+import prog8.code.core.SourceCode.Companion.LIBRARYFILEPREFIX
 import java.nio.file.InvalidPathException
 import kotlin.io.path.Path
 import kotlin.io.path.absolute
@@ -7,6 +8,10 @@ import kotlin.io.path.absolute
 data class Position(val file: String, val line: Int, val startCol: Int, val endCol: Int) {
    override fun toString(): String = "[$file: line $line col ${startCol+1}-${endCol+1}]"
    fun toClickableStr(): String {
+        if(this===DUMMY)
+            return ""
+        if(file.startsWith(LIBRARYFILEPREFIX))
+            return "$file:$line:$startCol:"
        return try {
            val path = Path(file).absolute().normalize().toString()
            "file://$path:$line:$startCol:"
@@ -3,6 +3,7 @@ package prog8.code.core
 import java.io.File
 import java.io.IOException
 import java.nio.file.Path
+import java.text.Normalizer
 import kotlin.io.path.Path
 import kotlin.io.path.readText

@@ -54,22 +55,25 @@ sealed class SourceCode {
        /**
         * filename prefix to designate library files that will be retreived from internal resources rather than disk
         */
-        const val libraryFilePrefix = "library:"
-        const val stringSourcePrefix = "string:"
+        const val LIBRARYFILEPREFIX = "library:"
+        const val STRINGSOURCEPREFIX = "string:"
        val curdir: Path = Path(".").toAbsolutePath()
        fun relative(path: Path): Path = curdir.relativize(path.toAbsolutePath())
        fun isRegularFilesystemPath(pathString: String) =
-            !(pathString.startsWith(libraryFilePrefix) || pathString.startsWith(stringSourcePrefix))
+            !(pathString.startsWith(LIBRARYFILEPREFIX) || pathString.startsWith(STRINGSOURCEPREFIX))
+
+        fun isLibraryResource(path: String) = path.startsWith(LIBRARYFILEPREFIX)
    }

    /**
     * Turn a plain String into a [SourceCode] object.
     * [origin] will be something like `string:44c56085`.
     */
-    class Text(override val text: String): SourceCode() {
+    class Text(origText: String): SourceCode() {
+        override val text = origText.replace("\\R".toRegex(), "\n")      // normalize line endings
        override val isFromResources = false
        override val isFromFilesystem = false
-        override val origin = "$stringSourcePrefix${System.identityHashCode(text).toString(16)}"
+        override val origin = "$STRINGSOURCEPREFIX${System.identityHashCode(text).toString(16)}"
        override val name = "<unnamed-text>"
    }

@@ -92,7 +96,8 @@ sealed class SourceCode {
            val normalized = path.normalize()
            origin = relative(normalized).toString()
            try {
-                text = normalized.readText()
+                val contents = Normalizer.normalize(normalized.readText(), Normalizer.Form.NFC)
+                text = contents.replace("\\R".toRegex(), "\n")      // normalize line endings
                name = normalized.toFile().nameWithoutExtension
            } catch (nfx: java.nio.file.NoSuchFileException) {
                throw NoSuchFileException(normalized.toFile()).also { it.initCause(nfx) }
@@ -110,7 +115,7 @@ sealed class SourceCode {

        override val isFromResources = true
        override val isFromFilesystem = false
-        override val origin = "$libraryFilePrefix$normalized"
+        override val origin = "$LIBRARYFILEPREFIX$normalized"
        override val text: String
        override val name: String

@@ -124,7 +129,8 @@ sealed class SourceCode {
                )
            }
            val stream = object {}.javaClass.getResourceAsStream(normalized)
-            text = stream!!.reader().use { it.readText() }
+            val contents = stream!!.reader().use { Normalizer.normalize(it.readText(), Normalizer.Form.NFC) }
+            text = contents.replace("\\R".toRegex(), "\n")      // normalize line endings
            name = Path(pathString).toFile().nameWithoutExtension
        }
    }
@@ -139,3 +145,33 @@ sealed class SourceCode {
        override val text: String = "<generated code node, no text representation>"
    }
 }
+
+
+object SourceLineCache {
+    private val cache = mutableMapOf<String, List<String>>()
+
+    private fun getCachedFile(file: String): List<String> {
+        val existing = cache[file]
+        if(existing!=null)
+            return existing
+        if (SourceCode.isRegularFilesystemPath(file)) {
+            val source = SourceCode.File(Path(file))
+            cache[file] = source.text.split('\n', '\r').map { it.trim() }
+            return cache.getValue(file)
+        } else if(file.startsWith(SourceCode.LIBRARYFILEPREFIX)) {
+            val source = SourceCode.Resource(file.drop(SourceCode.LIBRARYFILEPREFIX.length))
+            cache[file] = source.text.split('\n', '\r').map { it.trim()}
+            return cache.getValue(file)
+        }
+        return emptyList()
+    }
+
+    fun retrieveLine(position: Position): String? {
+        if (position.line>0) {
+            val lines = getCachedFile(position.file)
+            if(lines.isNotEmpty())
+                return lines[position.line-1]
+        }
+        return null
+    }
+}
@@ -0,0 +1,145 @@
+package prog8.code.optimize
+
+import prog8.code.StRomSub
+import prog8.code.SymbolTable
+import prog8.code.ast.*
+import prog8.code.core.*
+
+
+fun optimizeIntermediateAst(program: PtProgram, options: CompilationOptions, st: SymbolTable, errors: IErrorReporter) {
+    if (!options.optimize)
+        return
+    while (errors.noErrors() &&
+            (optimizeBitTest(program, options)
+            + optimizeAssignTargets(program, st, errors)) > 0
+    ) {
+        // keep rolling
+    }
+}
+
+
+private fun walkAst(root: PtNode, act: (node: PtNode, depth: Int) -> Boolean) {
+    fun recurse(node: PtNode, depth: Int) {
+        if(act(node, depth))
+            node.children.forEach { recurse(it, depth+1) }
+    }
+    recurse(root, 0)
+}
+
+
+private fun optimizeAssignTargets(program: PtProgram, st: SymbolTable, errors: IErrorReporter): Int {
+    var changes = 0
+    walkAst(program) { node: PtNode, depth: Int ->
+        if(node is PtAssignment) {
+            val value = node.value
+            val functionName = when(value) {
+                is PtBuiltinFunctionCall -> value.name
+                is PtFunctionCall -> value.name
+                else -> null
+            }
+            if(functionName!=null) {
+                val stNode = st.lookup(functionName)
+                if (stNode is StRomSub) {
+                    require(node.children.size==stNode.returns.size+1) {
+                        "number of targets must match return values"
+                    }
+                    node.children.zip(stNode.returns).withIndex().forEach { (index, xx) ->
+                        val target = xx.first as PtAssignTarget
+                        val returnedRegister = xx.second.register.registerOrPair
+                        if(returnedRegister!=null && !target.void && target.identifier!=null) {
+                            if(isSame(target.identifier!!, xx.second.type, returnedRegister)) {
+                                // output register is already identical to target register, so it can become void
+                                val voidTarget = PtAssignTarget(true, target.position)
+                                node.children[index] = voidTarget
+                                voidTarget.parent = node
+                                changes++
+                            }
+                        }
+                    }
+                }
+                if(node.children.dropLast(1).all { (it as PtAssignTarget).void }) {
+                    // all targets are now void, the whole assignment can be discarded and replaced by just a (void) call to the subroutine
+                    val index = node.parent.children.indexOf(node)
+                    val voidCall = PtFunctionCall(functionName, true, value.type, value.position)
+                    value.children.forEach { voidCall.add(it) }
+                    node.parent.children[index] = voidCall
+                    voidCall.parent = node.parent
+                    changes++
+                }
+            }
+        }
+        true
+    }
+    return changes
+}
+
+
+private fun optimizeBitTest(program: PtProgram, options: CompilationOptions): Int {
+    if(options.compTarget.machine.cpu == CpuType.VIRTUAL)
+        return 0        // the special bittest optimization is not yet valid for the IR
+
+    var changes = 0
+    var recurse = true
+    walkAst(program) { node: PtNode, depth: Int ->
+        if(node is PtIfElse) {
+            val condition = node.condition as? PtBinaryExpression
+            if(condition!=null && (condition.operator=="==" || condition.operator=="!=")) {
+                if(condition.right.asConstInteger()==0) {
+                    val and = condition.left as? PtBinaryExpression
+                    if(and != null && and.operator=="&" && and.type == DataType.UBYTE) {
+                        val variable = and.left as? PtIdentifier
+                        val bitmask = and.right.asConstInteger()
+                        if(variable!=null && variable.type in ByteDatatypes && (bitmask==128 || bitmask==64)) {
+                            val setOrNot = if(condition.operator=="!=") "set" else "notset"
+                            val index = node.parent.children.indexOf(node)
+                            val bittestCall = PtBuiltinFunctionCall("prog8_ifelse_bittest_$setOrNot", false, true, DataType.BOOL, node.condition.position)
+                            bittestCall.add(variable)
+                            if(bitmask==128)
+                                bittestCall.add(PtNumber(DataType.UBYTE, 7.0, and.right.position))
+                            else
+                                bittestCall.add(PtNumber(DataType.UBYTE, 6.0, and.right.position))
+                            val ifElse = PtIfElse(node.position)
+                            ifElse.add(bittestCall)
+                            ifElse.add(node.ifScope)
+                            if(node.hasElse())
+                                ifElse.add(node.elseScope)
+                            node.parent.children[index] = ifElse
+                            ifElse.parent = node.parent
+                            changes++
+                            recurse = false
+                        }
+                    }
+                }
+            }
+        }
+        recurse
+    }
+    return changes
+}
+
+
+internal fun isSame(identifier: PtIdentifier, type: DataType, returnedRegister: RegisterOrPair): Boolean {
+    if(returnedRegister in Cx16VirtualRegisters) {
+        val regname = returnedRegister.name.lowercase()
+        val identifierRegName = identifier.name.substringAfterLast('.')
+        /*
+            cx16.r?    UWORD
+            cx16.r?s   WORD
+            cx16.r?L   UBYTE
+            cx16.r?H   UBYTE
+            cx16.r?sL  BYTE
+            cx16.r?sH  BYTE
+         */
+        if(identifier.type in ByteDatatypes && type in ByteDatatypes) {
+            if(identifier.name.startsWith("cx16.$regname") && identifierRegName.startsWith(regname)) {
+                return identifierRegName.substring(2) in arrayOf("", "L", "sL")     // note: not the -H (msb) variants!
+            }
+        }
+        else if(identifier.type in WordDatatypes && type in WordDatatypes) {
+            if(identifier.name.startsWith("cx16.$regname") && identifierRegName.startsWith(regname)) {
+                return identifierRegName.substring(2) in arrayOf("", "s")
+            }
+        }
+    }
+    return false   // there are no identifiers directly corresponding to cpu registers
+}
@@ -7,7 +7,6 @@ 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 {
@@ -16,13 +15,17 @@ class AtariTarget: ICompilationTarget, IStringEncoding by Encoder, IMemSizer {

    override fun memorySize(dt: DataType): Int {
        return when(dt) {
-            in ByteDatatypes -> 1
+            in ByteDatatypesWithBoolean -> 1
            in WordDatatypes, in PassByReferenceDatatypes -> 2
            DataType.FLOAT -> machine.FLOAT_MEM_SIZE
-            else -> Int.MIN_VALUE
+            else -> throw IllegalArgumentException("invalid datatype")
        }
    }

    override fun memorySize(arrayDt: DataType, numElements: Int) =
-        memorySize(ArrayToElementTypes.getValue(arrayDt)) * numElements
+        if(arrayDt==DataType.UWORD)
+            numElements    // pointer to bytes.
+        else
+            memorySize(ArrayToElementTypes.getValue(arrayDt)) * numElements
+
 }
@@ -11,7 +11,6 @@ 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 {
@@ -11,10 +11,31 @@ 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"
+
+        fun viceMonListName(baseFilename: String) = "$baseFilename.vice-mon-list"
    }
 }
+
+
+val CompilationTargets = listOf(
+    C64Target.NAME,
+    C128Target.NAME,
+    Cx16Target.NAME,
+    PETTarget.NAME,
+    AtariTarget.NAME,
+    VMTarget.NAME
+)
+
+fun getCompilationTargetByName(name: String) = when(name.lowercase()) {
+    C64Target.NAME -> C64Target()
+    C128Target.NAME -> C128Target()
+    Cx16Target.NAME -> Cx16Target()
+    PETTarget.NAME -> PETTarget()
+    AtariTarget.NAME -> AtariTarget()
+    VMTarget.NAME -> VMTarget()
+    else -> throw IllegalArgumentException("invalid compilation target")
+}
@@ -11,7 +11,6 @@ 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 {
@@ -4,18 +4,22 @@ 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
+import prog8.code.target.encodings.*


 object Encoder: IStringEncoding {
+    override val defaultEncoding: Encoding = Encoding.ISO
+
    override fun encodeString(str: String, encoding: Encoding): List<UByte> {
        val coded = when(encoding) {
            Encoding.PETSCII -> PetsciiEncoding.encodePetscii(str, true)
            Encoding.SCREENCODES -> PetsciiEncoding.encodeScreencode(str, true)
            Encoding.ISO -> IsoEncoding.encode(str)
            Encoding.ATASCII -> AtasciiEncoding.encode(str)
+            Encoding.ISO5 -> IsoCyrillicEncoding.encode(str)
+            Encoding.ISO16 -> IsoEasternEncoding.encode(str)
+            Encoding.CP437 -> Cp437Encoding.encode(str)
+            Encoding.KATAKANA -> KatakanaEncoding.encode(str)
            else -> throw InternalCompilerException("unsupported encoding $encoding")
        }
        return coded.fold(
@@ -29,6 +33,10 @@ object Encoder: IStringEncoding {
            Encoding.SCREENCODES -> PetsciiEncoding.decodeScreencode(bytes, true)
            Encoding.ISO -> IsoEncoding.decode(bytes)
            Encoding.ATASCII -> AtasciiEncoding.decode(bytes)
+            Encoding.ISO5 -> IsoCyrillicEncoding.decode(bytes)
+            Encoding.ISO16 -> IsoEasternEncoding.decode(bytes)
+            Encoding.CP437 -> Cp437Encoding.decode(bytes)
+            Encoding.KATAKANA -> KatakanaEncoding.decode(bytes)
            else -> throw InternalCompilerException("unsupported encoding $encoding")
        }
        return decoded.fold(
@@ -0,0 +1,19 @@
+package prog8.code.target
+
+import prog8.code.core.Encoding
+import prog8.code.core.ICompilationTarget
+import prog8.code.core.IMemSizer
+import prog8.code.core.IStringEncoding
+import prog8.code.target.cbm.CbmMemorySizer
+import prog8.code.target.pet.PETMachineDefinition
+
+
+class PETTarget: ICompilationTarget, IStringEncoding by Encoder, IMemSizer by CbmMemorySizer {
+    override val name = NAME
+    override val machine = PETMachineDefinition()
+    override val defaultEncoding = Encoding.PETSCII
+
+    companion object {
+        const val NAME = "pet32"
+    }
+}
@@ -6,7 +6,6 @@ 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 {
@@ -15,13 +14,16 @@ class VMTarget: ICompilationTarget, IStringEncoding by Encoder, IMemSizer {

    override fun memorySize(dt: DataType): Int {
        return when(dt) {
-            in ByteDatatypes -> 1
+            in ByteDatatypesWithBoolean -> 1
            in WordDatatypes, in PassByReferenceDatatypes -> 2
            DataType.FLOAT -> machine.FLOAT_MEM_SIZE
-            else -> Int.MIN_VALUE
+            else -> throw IllegalArgumentException("invalid datatype")
        }
    }

    override fun memorySize(arrayDt: DataType, numElements: Int) =
-        memorySize(ArrayToElementTypes.getValue(arrayDt)) * numElements
+        if(arrayDt==DataType.UWORD)
+            numElements    // pointer to bytes.
+        else
+            memorySize(ArrayToElementTypes.getValue(arrayDt)) * numElements
 }
@@ -13,24 +13,17 @@ class AtariMachineDefinition: IMachineDefinition {
    override val FLOAT_MEM_SIZE = 6
    override val PROGRAM_LOAD_ADDRESS = 0x2000u

-    // the 2*128 byte evaluation stack (1 page, on which bytes, words, and even floats are stored during calculations)
-    override var ESTACK_LO = 0x1b00u     //  $1b00-$1b7f inclusive      // TODO
-    override var ESTACK_HI = 0x1b80u     //  $1b80-$1bff inclusive      // TODO
-
    override val BSSHIGHRAM_START = 0u    // TODO
    override val BSSHIGHRAM_END = 0u      // TODO
+    override val BSSGOLDENRAM_START = 0u  // TODO
+    override val BSSGOLDENRAM_END = 0u    // TODO

    override lateinit var zeropage: Zeropage
    override lateinit var golden: GoldenRam

-    override fun getFloatAsmBytes(num: Number) = TODO("float asm bytes from number")
-
-    override fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
-        return if (compilerOptions.output == OutputType.XEX)
-            listOf("syslib")
-        else
-            emptyList()
-    }
+    override fun getFloatAsmBytes(num: Number) = TODO("atari float asm bytes from number")
+    override fun convertFloatToBytes(num: Double): List<UByte> = TODO("atari float to bytes")
+    override fun convertBytesToFloat(bytes: List<UByte>): Double = TODO("atari bytes to float")

    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
        val emulatorName: String
@@ -13,6 +13,10 @@ class AtariZeropage(options: CompilationOptions) : Zeropage(options) {
    override val SCRATCH_W2 = 0xcfu      // temp storage 2 for a word  $cf+$d0        TODO is $d0 okay to use?

    init {
+        if (options.floats) {
+            throw InternalCompilerException("Atari target doesn't yet support floating point routines")
+        }
+
        if (options.floats && options.zeropage !in arrayOf(
                ZeropageType.FLOATSAFE,
                ZeropageType.BASICSAFE,
@@ -39,11 +43,12 @@ class AtariZeropage(options: CompilationOptions) : Zeropage(options) {
            }
        }

-        val distictFree = free.distinct()
+        val distinctFree = free.distinct()
        free.clear()
-        free.addAll(distictFree)
+        free.addAll(distinctFree)

        removeReservedFromFreePool()
+        retainAllowed()
    }

    override fun allocateCx16VirtualRegisters() {
@@ -1,6 +1,7 @@
 package prog8.code.target.c128

 import prog8.code.core.*
+import prog8.code.target.C64Target
 import prog8.code.target.cbm.Mflpt5
 import java.nio.file.Path

@@ -14,23 +15,25 @@ class C128MachineDefinition: IMachineDefinition {
    override val FLOAT_MEM_SIZE = Mflpt5.FLOAT_MEM_SIZE
    override val PROGRAM_LOAD_ADDRESS = 0x1c01u

-    // the 2*128 byte evaluation stack (1 page, on which bytes, words, and even floats are stored during calculations)
-    override var ESTACK_LO = 0x1b00u     //  $1b00-$1b7f inclusive
-    override var ESTACK_HI = 0x1b80u     //  $1b80-$1bff inclusive
-
    override val BSSHIGHRAM_START = 0u    // TODO
    override val BSSHIGHRAM_END = 0u      // TODO
+    override val BSSGOLDENRAM_START = 0u  // TODO
+    override val BSSGOLDENRAM_END = 0u    // TODO

    override lateinit var zeropage: Zeropage
    override lateinit var golden: GoldenRam

    override fun getFloatAsmBytes(num: Number) = Mflpt5.fromNumber(num).makeFloatFillAsm()

-    override fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
-        return if (compilerOptions.launcher == CbmPrgLauncherType.BASIC || compilerOptions.output == OutputType.PRG)
-            listOf("syslib")
-        else
-            emptyList()
+    override fun convertFloatToBytes(num: Double): List<UByte> {
+        val m5 = Mflpt5.fromNumber(num)
+        return listOf(m5.b0, m5.b1, m5.b2, m5.b3, m5.b4)
+    }
+
+    override fun convertBytesToFloat(bytes: List<UByte>): Double {
+        require(bytes.size==5) { "need 5 bytes" }
+        val m5 = Mflpt5(bytes[0], bytes[1], bytes[2], bytes[3], bytes[4])
+        return m5.toDouble()
    }

    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
@@ -40,7 +43,7 @@ class C128MachineDefinition: IMachineDefinition {
        }

        println("\nStarting C-128 emulator x128...")
-        val viceMonlist = viceMonListName(programNameWithPath.toString())
+        val viceMonlist = C64Target.viceMonListName(programNameWithPath.toString())
        val cmdline = listOf("x128", "-silent", "-moncommands", viceMonlist,
                "-autostartprgmode", "1", "-autostart-warp", "-autostart", "${programNameWithPath}.prg")
        val processb = ProcessBuilder(cmdline).inheritIO()
@@ -6,15 +6,22 @@ import prog8.code.core.Zeropage
 import prog8.code.core.ZeropageType


+// reference: "Mapping the C128" zero page chapter.
+
 class C128Zeropage(options: CompilationOptions) : Zeropage(options) {

-    override val SCRATCH_B1 = 0x9bu      // temp storage for a single byte
-    override val SCRATCH_REG = 0x9cu     // temp storage for a register, must be B1+1
+    override val SCRATCH_B1 = 0x74u      // temp storage for a single byte
+    override val SCRATCH_REG = 0x75u     // temp storage for a register, must be B1+1
    override val SCRATCH_W1 = 0xfbu      // temp storage 1 for a word  $fb+$fc
    override val SCRATCH_W2 = 0xfdu      // temp storage 2 for a word  $fd+$fe

-
    init {
+        if (options.floats) {
+            throw InternalCompilerException("C128 target doesn't yet support floating point routines")
+            // note: in git commit labeled 'c128: remove floats module' the floats.p8 and floats.asm files are removed,
+            //       they could be retrieved again at a later time if the compiler somehow *does* store the fp variables in bank1.
+        }
+
        if (options.floats && options.zeropage !in arrayOf(
                ZeropageType.FLOATSAFE,
                ZeropageType.BASICSAFE,
@@ -24,25 +31,45 @@ class C128Zeropage(options: CompilationOptions) : Zeropage(options) {

        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
+                // $00/$01 are data port IO registers, // $02-$09 are storage locations for JSRFAR and such
+                free.addAll(0x0au..0xffu)
+                free.removeAll(listOf(0x90u, 0x91u, 0xa0u, 0xa1u, 0xa2u, 0xc0u, 0xccu, 0xcdu, 0xd0u, 0xd1u, 0xd2u, 0xd3u, 0xd4u, 0xd5u, 0xf7u))        // these are updated/used by IRQ
+            }
+            ZeropageType.KERNALSAFE -> {
+                free.addAll(0x0au..0x8fu)       // BASIC variables
+                free.addAll(listOf(0x92u, 0x96u, 0x9bu, 0x9cu, 0x9eu, 0x9fu, 0xa4u, 0xa7u, 0xa8u, 0xa9u, 0xaau, 0xabu,
+                    0xb0u, 0xb1u, 0xb4u, 0xb5u, 0xb6u))
            }
-            ZeropageType.KERNALSAFE,
            ZeropageType.FLOATSAFE,
            ZeropageType.BASICSAFE -> {
-                free.clear()   // TODO c128 usable zero page addresses
+                free.addAll(listOf(0x0bu, 0x0cu, 0x0du, 0x0eu, 0x0fu, 0x10u, 0x11u, 0x12u, 0x16u, 0x17u, 0x18u, 0x19u, 0x1au))
+                free.addAll(0x1bu..0x23u)
+                free.addAll(listOf(0x3fu, 0x40u, 0x41u, 0x42u, 0x43u, 0x44u, 0x47u, 0x48u, 0x49u, 0x4au, 0x4bu, 0x4cu, 0x4fu,
+                    0x55u, 0x56u, 0x57u, 0x58u,
+                    0x74u, 0x75u, 0x78u, 0x80u, 0x83u, 0x87u, 0x88u, 0x89u, 0x8au, 0x8bu, 0x8cu, 0x8du, 0x8eu, 0x8fu,
+                    0x92u, 0x96u, 0x9bu, 0x9cu, 0x9eu, 0x9fu, 0xa4u, 0xa7u, 0xa8u, 0xa9u, 0xaau, 0xabu,
+                    0xb0u, 0xb1u, 0xb4u, 0xb5u, 0xb6u
+                ))
+
+                // if(options.zeropage==ZeropageType.BASICSAFE) {
+                    // can also clobber the FP locations (unconditionally, because the C128 target doesn't support floating point calculations in prog8 at this time0
+                    free.addAll(listOf(0x14u, 0x28u, 0x29u, 0x2au, 0x2bu, 0x2cu,
+                        0x50u, 0x51u, 0x52u, 0x53u, 0x54u, 0x59u, 0x5au, 0x5bu, 0x5cu, 0x5du, 0x5eu, 0x5fu, 0x60u, 0x61u, 0x62u,
+                        0x63u, 0x64u, 0x65u, 0x66u, 0x67u, 0x68u,
+                        0x6au, 0x6bu, 0x6cu, 0x6du, 0x6eu, 0x6fu, 0x71u))
+                // }
            }
            ZeropageType.DONTUSE -> {
                free.clear()  // don't use zeropage at all
            }
        }

-        val distictFree = free.distinct()
+        val distinctFree = free.distinct()
        free.clear()
-        free.addAll(distictFree)
+        free.addAll(distinctFree)

        removeReservedFromFreePool()
+        retainAllowed()
    }

    override fun allocateCx16VirtualRegisters() {
@@ -1,6 +1,7 @@
 package prog8.code.target.c64

 import prog8.code.core.*
+import prog8.code.target.C64Target
 import prog8.code.target.cbm.Mflpt5
 import java.io.IOException
 import java.nio.file.Path
@@ -15,23 +16,25 @@ class C64MachineDefinition: IMachineDefinition {
    override val FLOAT_MEM_SIZE = Mflpt5.FLOAT_MEM_SIZE
    override val PROGRAM_LOAD_ADDRESS = 0x0801u

-    // the 2*128 byte evaluation stack (1 page, on which bytes, words, and even floats are stored during calculations)
-    override var ESTACK_LO = 0xcf00u     //  $cf00-$cf7f inclusive
-    override var ESTACK_HI = 0xcf80u     //  $cf80-$cfff inclusive
-
    override val BSSHIGHRAM_START = 0xc000u
-    override val BSSHIGHRAM_END = ESTACK_LO
+    override val BSSHIGHRAM_END = 0xcfffu
+    override val BSSGOLDENRAM_START = 0u
+    override val BSSGOLDENRAM_END = 0u

    override lateinit var zeropage: Zeropage
    override lateinit var golden: GoldenRam

    override fun getFloatAsmBytes(num: Number) = Mflpt5.fromNumber(num).makeFloatFillAsm()

-    override fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
-        return if (compilerOptions.launcher == CbmPrgLauncherType.BASIC || compilerOptions.output == OutputType.PRG)
-            listOf("syslib")
-        else
-            emptyList()
+    override fun convertFloatToBytes(num: Double): List<UByte> {
+        val m5 = Mflpt5.fromNumber(num)
+        return listOf(m5.b0, m5.b1, m5.b2, m5.b3, m5.b4)
+    }
+
+    override fun convertBytesToFloat(bytes: List<UByte>): Double {
+        require(bytes.size==5) { "need 5 bytes" }
+        val m5 = Mflpt5(bytes[0], bytes[1], bytes[2], bytes[3], bytes[4])
+        return m5.toDouble()
    }

    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
@@ -42,7 +45,7 @@ class C64MachineDefinition: IMachineDefinition {

        for(emulator in listOf("x64sc", "x64")) {
            println("\nStarting C-64 emulator $emulator...")
-            val viceMonlist = viceMonListName(programNameWithPath.toString())
+            val viceMonlist = C64Target.viceMonListName(programNameWithPath.toString())
            val cmdline = listOf(emulator, "-silent", "-moncommands", viceMonlist,
                    "-autostartprgmode", "1", "-autostart-warp", "-autostart", "${programNameWithPath}.prg")
            val processb = ProcessBuilder(cmdline).inheritIO()
@@ -61,7 +64,7 @@ class C64MachineDefinition: IMachineDefinition {

    override fun initializeMemoryAreas(compilerOptions: CompilationOptions) {
        zeropage = C64Zeropage(compilerOptions)
-        golden = GoldenRam(compilerOptions, 0xc000u until ESTACK_LO)
+        golden = GoldenRam(compilerOptions, 0xc000u until 0xd000u)
    }

 }
@@ -44,7 +44,7 @@ class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
            if (options.zeropage == ZeropageType.FLOATSAFE) {
                // remove the zeropage locations used for floating point operations from the free list
                free.removeAll(listOf(
-                        0x03, 0x04, 0x10, 0x11, 0x12,
+                        0x03, 0x04, 0x05, 0x06, 0x10, 0x11, 0x12,
                        0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a,
                        0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
                        0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
@@ -53,11 +53,11 @@ class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
                ).map{it.toUInt()})
            }

-            if(options.zeropage!= ZeropageType.DONTUSE) {
+            if(options.zeropage != ZeropageType.DONTUSE) {
                // add the free Zp addresses
                // these are valid for the C-64 but allow BASIC to keep running fully *as long as you don't use tape I/O*
                free.addAll(listOf(0x02, 0x03, 0x04, 0x05, 0x06, 0x0a, 0x0e,
-                        0x92, 0x96, 0x9b, 0x9c, 0x9e, 0x9f, 0xa5, 0xa6,
+                        0x92, 0x96, 0x9b, 0x9c, 0x9e, 0x9f, 0xa6,
                        0xb0, 0xb1, 0xbe, 0xbf, 0xf9).map{it.toUInt()})
            } else {
                // don't use the zeropage at all
@@ -65,9 +65,9 @@ class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
            }
        }

-        val distictFree = free.distinct()
+        val distinctFree = free.distinct()
        free.clear()
-        free.addAll(distictFree)
+        free.addAll(distinctFree)

        removeReservedFromFreePool()

@@ -75,6 +75,8 @@ class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
            // in these cases there is enough space on the zero page to stick the cx16 virtual registers in there as well.
            allocateCx16VirtualRegisters()
        }
+
+        retainAllowed()
    }

    override fun allocateCx16VirtualRegisters() {
@@ -6,13 +6,16 @@ import prog8.code.core.*
 internal object CbmMemorySizer: IMemSizer {
    override fun memorySize(dt: DataType): Int {
        return when(dt) {
-            in ByteDatatypes -> 1
+            in ByteDatatypesWithBoolean -> 1
            in WordDatatypes, in PassByReferenceDatatypes -> 2
            DataType.FLOAT -> Mflpt5.FLOAT_MEM_SIZE
-            else -> Int.MIN_VALUE
+            else -> throw IllegalArgumentException("invalid datatype")
        }
    }

    override fun memorySize(arrayDt: DataType, numElements: Int) =
-        memorySize(ArrayToElementTypes.getValue(arrayDt)) * numElements
+        if(arrayDt==DataType.UWORD)
+            numElements    // pointer to bytes.
+        else
+            memorySize(ArrayToElementTypes.getValue(arrayDt)) * numElements
 }
@@ -1,6 +1,7 @@
 package prog8.code.target.cx16

 import prog8.code.core.*
+import prog8.code.target.C64Target
 import prog8.code.target.cbm.Mflpt5
 import java.nio.file.Path

@@ -14,22 +15,25 @@ class CX16MachineDefinition: IMachineDefinition {
    override val FLOAT_MEM_SIZE = Mflpt5.FLOAT_MEM_SIZE
    override val PROGRAM_LOAD_ADDRESS = 0x0801u

-    // the 2*128 byte evaluation stack (1 page, on which bytes, words, and even floats are stored during calculations)
-    override var ESTACK_LO = 0x0700u        //  $0700-$077f inclusive
-    override var ESTACK_HI = 0x0780u        //  $0780-$07ff inclusive
-
    override val BSSHIGHRAM_START = 0xa000u     // hiram bank 1, 8Kb, assumed to be active
-    override val BSSHIGHRAM_END = 0xc000u       // rom starts here.
+    override val BSSHIGHRAM_END = 0xbfffu       // Rom starts at $c000
+    override val BSSGOLDENRAM_START = 0x0400u
+    override val BSSGOLDENRAM_END = 0x07ffu

    override lateinit var zeropage: Zeropage
    override lateinit var golden: GoldenRam

    override fun getFloatAsmBytes(num: Number) = Mflpt5.fromNumber(num).makeFloatFillAsm()
-    override fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
-        return if (compilerOptions.launcher == CbmPrgLauncherType.BASIC || compilerOptions.output == OutputType.PRG)
-            listOf("syslib")
-        else
-            emptyList()
+
+    override fun convertFloatToBytes(num: Double): List<UByte> {
+        val m5 = Mflpt5.fromNumber(num)
+        return listOf(m5.b0, m5.b1, m5.b2, m5.b3, m5.b4)
+    }
+
+    override fun convertBytesToFloat(bytes: List<UByte>): Double {
+        require(bytes.size==5) { "need 5 bytes" }
+        val m5 = Mflpt5(bytes[0], bytes[1], bytes[2], bytes[3], bytes[4])
+        return m5.toDouble()
    }

    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
@@ -39,11 +43,11 @@ class CX16MachineDefinition: IMachineDefinition {
        when(selectedEmulator) {
            1 -> {
                emulator = "x16emu"
-                extraArgs = emptyList()
+                extraArgs = listOf("-debug")
            }
            2 -> {
                emulator = "box16"
-                extraArgs = listOf("-sym", viceMonListName(programNameWithPath.toString()))
+                extraArgs = listOf("-sym", C64Target.viceMonListName(programNameWithPath.toString()))
            }
            else -> {
                System.err.println("Cx16 target only supports x16emu and box16 emulators.")
@@ -52,7 +56,7 @@ class CX16MachineDefinition: IMachineDefinition {
        }

        println("\nStarting Commander X16 emulator $emulator...")
-        val cmdline = listOf(emulator, "-scale", "2", "-run", "-prg", "${programNameWithPath}.prg") + extraArgs
+        val cmdline = listOf(emulator, "-scale", "2", "-rtc", "-run", "-prg", "${programNameWithPath}.prg") + extraArgs
        val processb = ProcessBuilder(cmdline).inheritIO()
        processb.environment()["PULSE_LATENCY_MSEC"] = "10"
        val process: Process = processb.start()
@@ -63,7 +67,7 @@ class CX16MachineDefinition: IMachineDefinition {

    override fun initializeMemoryAreas(compilerOptions: CompilationOptions) {
        zeropage = CX16Zeropage(compilerOptions)
-        golden = GoldenRam(compilerOptions, 0x0600u until 0x0800u)
+        golden = GoldenRam(compilerOptions, 0x0400u until 0x0800u)
    }

 }
@@ -40,16 +40,15 @@ class CX16Zeropage(options: CompilationOptions) : Zeropage(options) {
                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}")
            }

-            val distictFree = free.distinct()
+            val distinctFree = free.distinct()
            free.clear()
-            free.addAll(distictFree)
+            free.addAll(distinctFree)

            removeReservedFromFreePool()
-
            allocateCx16VirtualRegisters()
+            retainAllowed()
        }
    }

@@ -1,4 +1,4 @@
-package prog8.code.target.cbm
+package prog8.code.target.encodings

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

 import com.github.michaelbull.result.Err
 import com.github.michaelbull.result.Ok
@@ -6,8 +6,8 @@ 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")
+open class IsoEncodingBase(charsetName: String) {
+    val charset: Charset = Charset.forName(charsetName)

    fun encode(str: String): Result<List<UByte>, CharConversionException> {
        return try {
@@ -35,3 +35,8 @@ object IsoEncoding {
        }
    }
 }
+
+
+object IsoEncoding: IsoEncodingBase("ISO-8859-15")
+object IsoCyrillicEncoding: IsoEncodingBase("ISO-8859-5")
+object IsoEasternEncoding: IsoEncodingBase("ISO-8859-16")
@@ -0,0 +1,122 @@
+package prog8.code.target.encodings
+
+import com.github.michaelbull.result.Err
+import com.github.michaelbull.result.Ok
+import com.github.michaelbull.result.Result
+import java.io.CharConversionException
+import java.nio.charset.Charset
+
+
+object JapaneseCharacterConverter {
+    // adapted from https://github.com/raminduw/Japanese-Character-Converter
+
+    private val ZENKAKU_KATAKANA = charArrayOf(
+        'ァ', 'ア', 'ィ', 'イ', 'ゥ',
+        'ウ', 'ェ', 'エ', 'ォ', 'オ', 'カ', 'ガ', 'キ', 'ギ', 'ク', 'グ', 'ケ', 'ゲ',
+        'コ', 'ゴ', 'サ', 'ザ', 'シ', 'ジ', 'ス', 'ズ', 'セ', 'ゼ', 'ソ', 'ゾ', 'タ',
+        'ダ', 'チ', 'ヂ', 'ッ', 'ツ', 'ヅ', 'テ', 'デ', 'ト', 'ド', 'ナ', 'ニ', 'ヌ',
+        'ネ', 'ノ', 'ハ', 'バ', 'パ', 'ヒ', 'ビ', 'ピ', 'フ', 'ブ', 'プ', 'ヘ', 'ベ',
+        'ペ', 'ホ', 'ボ', 'ポ', 'マ', 'ミ', 'ム', 'メ', 'モ', 'ャ', 'ヤ', 'ュ', 'ユ',
+        'ョ', 'ヨ', 'ラ', 'リ', 'ル', 'レ', 'ロ', 'ヮ', 'ワ', 'ヰ', 'ヱ', 'ヲ', 'ン',
+        'ヴ', 'ヵ', 'ヶ'
+    )
+
+    private val HANKAKU_HIRAGANA = charArrayOf(
+        'ぁ', 'あ', 'ぃ', 'い', 'ぅ', 'う', 'ぇ', 'え',
+        'ぉ', 'お', 'か', 'が', 'き', 'ぎ', 'く', 'ぐ',
+        'け', 'げ', 'こ', 'ご', 'さ', 'ざ', 'し', 'じ',
+        'す', 'ず', 'せ', 'ぜ', 'そ', 'ぞ', 'た', 'だ',
+        'ち', 'ぢ', 'っ', 'つ', 'づ', 'て', 'で', 'と',
+        'ど', 'な', 'に', 'ぬ', 'ね', 'の', 'は', 'ば',
+        'ぱ', 'ひ', 'び', 'ぴ', 'ふ', 'ぶ', 'ぷ', 'へ',
+        'べ', 'ぺ', 'ほ', 'ぼ', 'ぽ', 'ま', 'み', 'む',
+        'め', 'も', 'ゃ', 'や', 'ゅ', 'ゆ', 'ょ', 'よ',
+        'ら', 'り', 'る', 'れ', 'ろ', 'ゎ', 'わ', 'ゐ',
+        'ゑ', 'を', 'ん', 'ゔ', 'ゕ', 'ゖ'
+    )
+
+    private val HANKAKU_KATAKANA = arrayOf(
+        "ｧ", "ｱ", "ｨ", "ｲ", "ｩ",
+        "ｳ", "ｪ", "ｴ", "ｫ", "ｵ", "ｶ", "ｶﾞ", "ｷ", "ｷﾞ", "ｸ", "ｸﾞ", "ｹ",
+        "ｹﾞ", "ｺ", "ｺﾞ", "ｻ", "ｻﾞ", "ｼ", "ｼﾞ", "ｽ", "ｽﾞ", "ｾ", "ｾﾞ", "ｿ",
+        "ｿﾞ", "ﾀ", "ﾀﾞ", "ﾁ", "ﾁﾞ", "ｯ", "ﾂ", "ﾂﾞ", "ﾃ", "ﾃﾞ", "ﾄ", "ﾄﾞ",
+        "ﾅ", "ﾆ", "ﾇ", "ﾈ", "ﾉ", "ﾊ", "ﾊﾞ", "ﾊﾟ", "ﾋ", "ﾋﾞ", "ﾋﾟ", "ﾌ",
+        "ﾌﾞ", "ﾌﾟ", "ﾍ", "ﾍﾞ", "ﾍﾟ", "ﾎ", "ﾎﾞ", "ﾎﾟ", "ﾏ", "ﾐ", "ﾑ", "ﾒ",
+        "ﾓ", "ｬ", "ﾔ", "ｭ", "ﾕ", "ｮ", "ﾖ", "ﾗ", "ﾘ", "ﾙ", "ﾚ", "ﾛ", "ﾜ",
+        "ﾜ", "ｲ", "ｴ", "ｦ", "ﾝ", "ｳﾞ", "ｶ", "ｹ"
+    )
+
+    private val ZENKAKU_KATAKANA_FIRST_CHAR_CODE = ZENKAKU_KATAKANA.first().code
+    private val HANKAKU_HIRAGANA_FIRST_CHAR_CODE = HANKAKU_HIRAGANA.first().code
+
+    private fun zenkakuKatakanaToHankakuKatakana(c: Char): String = if (c in ZENKAKU_KATAKANA) HANKAKU_KATAKANA[c.code - ZENKAKU_KATAKANA_FIRST_CHAR_CODE] else c.toString()
+    private fun hankakuKatakanaToZenkakuKatakana(c: Char): Char = if (c in HANKAKU_HIRAGANA) ZENKAKU_KATAKANA[c.code - HANKAKU_HIRAGANA_FIRST_CHAR_CODE] else c
+
+    fun zenkakuKatakanaToHankakuKatakana(s: String): String = buildString {
+        for (element in s) {
+            val converted = hankakuKatakanaToZenkakuKatakana(element)
+            val convertedChar = zenkakuKatakanaToHankakuKatakana(converted)
+            append(convertedChar)
+        }
+    }
+}
+
+object KatakanaEncoding {
+    val charset: Charset = Charset.forName("JIS_X0201")
+
+    fun encode(str: String): Result<List<UByte>, CharConversionException> {
+        return try {
+            val mapped = str.map { chr ->
+                when (chr) {
+
+                    '\u0000' -> 0u
+                    '\u00a0' -> 0xa0u // $a0 isn't technically a part of JIS X 0201 spec, and so we need to handle this ourselves
+
+                    '♥' -> 0xe3u
+                    '♦' -> 0xe4u
+                    '♣' -> 0xe5u
+                    '♠' -> 0xe6u
+
+                    '大' -> 0xeau
+                    '中' -> 0xebu
+                    '小' -> 0xecu
+                    '百' -> 0xedu
+                    '千' -> 0xeeu
+                    '万' -> 0xefu
+                    '♪' -> 0xf0u
+                    '土' -> 0xf1u
+                    '金' -> 0xf2u
+                    '木' -> 0xf3u
+                    '水' -> 0xf4u
+                    '火' -> 0xf5u
+                    '月' -> 0xf6u
+                    '日' -> 0xf7u
+                    '時' -> 0xf8u
+                    '分' -> 0xf9u
+                    '秒' -> 0xfau
+                    '年' -> 0xfbu
+                    '円' -> 0xfcu
+                    '人' -> 0xfdu
+                    '生' -> 0xfeu
+                    '〒' -> 0xffu
+                    in '\u8000'..'\u80ff' -> {
+                        // special case: take the lower 8 bit hex value directly
+                        (chr.code - 0x8000).toUByte()
+                    }
+                    else -> charset.encode(chr.toString())[0].toUByte()
+                }
+            }
+            Ok(mapped)
+        } catch (ce: CharConversionException) {
+            Err(ce)
+        }
+    }
+
+    fun decode(bytes: Iterable<UByte>): Result<String, CharConversionException> {
+        return try {
+            Ok(String(bytes.map { it.toByte() }.toByteArray(), charset))
+        } catch (ce: CharConversionException) {
+            Err(ce)
+        }
+    }
+}
@@ -1,4 +1,4 @@
-package prog8.code.target.cbm
+package prog8.code.target.encodings

 import com.github.michaelbull.result.Err
 import com.github.michaelbull.result.Ok
@@ -24,7 +24,7 @@ object PetsciiEncoding {
        '\ufffe',    //       0x0A -> UNDEFINED
        '\ufffe',    //       0x0B -> UNDEFINED
        '\ufffe',    //       0x0C -> UNDEFINED
-        '\r'    ,    //       0x0D -> CARRIAGE RETURN
+        '\n'    ,    //       0x0D -> LINE FEED (RETURN)
        '\u000e',    //       0x0E -> SHIFT OUT
        '\ufffe',    //       0x0F -> UNDEFINED
        '\ufffe',    //       0x10 -> UNDEFINED
@@ -152,7 +152,7 @@ object PetsciiEncoding {
        '\uf113',    //      0x8A -> FUNCTION KEY 4 (CUS)
        '\uf115',    //      0x8B -> FUNCTION KEY 6 (CUS)
        '\uf117',    //      0x8C -> FUNCTION KEY 8 (CUS)
-        '\n'    ,    //       0x8D -> LINE FEED
+        '\r'    ,    //       0x8D -> CARRIAGE RETURN (SHIFT-RETURN)
        '\u000f',    //      0x8E -> SHIFT IN
        '\ufffe',    //       0x8F -> UNDEFINED
        '\uf105',    //       0x90 -> BLACK COLOR SWITCH (CUS)
@@ -283,7 +283,7 @@ object PetsciiEncoding {
        '\ufffe',    //       0x0A -> UNDEFINED
        '\ufffe',    //       0x0B -> UNDEFINED
        '\ufffe',    //       0x0C -> UNDEFINED
-        '\r'    ,    //       0x0D -> CARRIAGE RETURN
+        '\n'    ,    //       0x0D -> LINE FEED (RETURN)
        '\u000e',    //       0x0E -> SHIFT OUT
        '\ufffe',    //       0x0F -> UNDEFINED
        '\ufffe',    //       0x10 -> UNDEFINED
@@ -411,7 +411,7 @@ object PetsciiEncoding {
        '\uf113',    //       0x8A -> FUNCTION KEY 4 (CUS)
        '\uf115',    //       0x8B -> FUNCTION KEY 6 (CUS)
        '\uf117',    //       0x8C -> FUNCTION KEY 8 (CUS)
-        '\n'    ,    //       0x8D -> LINE FEED
+        '\r'    ,    //       0x8D -> CARRIAGE RETURN (SHIFT-RETURN)
        '\u000f',    //       0x8E -> SHIFT IN
        '\ufffe',    //       0x8F -> UNDEFINED
        '\uf105',    //       0x90 -> BLACK COLOR SWITCH (CUS)
@@ -1061,6 +1061,7 @@ object PetsciiEncoding {
            '}' -> '├'
            '|' -> '│'
            '\\' -> '╲'
+            '\r' -> '\n'        // to make \r (carriage returrn) equivalent to \n (line feed): RETURN ($0d)
            else -> chr
        }

@@ -1076,7 +1077,10 @@ object PetsciiEncoding {
                }
                else -> {
                    val case = if (lowercase) "lower" else "upper"
-                    throw CharConversionException("no ${case}Petscii character for '${chr}' (${chr.code})")
+                    if(chr.isISOControl())
+                        throw CharConversionException("no ${case}Petscii character for char #${chr.code}")
+                    else
+                        throw CharConversionException("no ${case}Petscii character for char #${chr.code} '${chr}'")
                }
            }
        }
@@ -1119,7 +1123,10 @@ object PetsciiEncoding {
                }
                else -> {
                    val case = if (lowercase) "lower" else "upper"
-                    throw CharConversionException("no ${case}Screencode character for '${chr}' (${chr.code})")
+                    if(chr.isISOControl())
+                        throw CharConversionException("no ${case}Screencode character for char #${chr.code}")
+                    else
+                        throw CharConversionException("no ${case}Screencode character for char #${chr.code} '${chr}'")
                }
            }
        }
@@ -0,0 +1,61 @@
+package prog8.code.target.pet
+
+import prog8.code.core.*
+import prog8.code.target.C64Target
+import prog8.code.target.cbm.Mflpt5
+import java.nio.file.Path
+
+
+class PETMachineDefinition: IMachineDefinition {
+
+    override val cpu = CpuType.CPU6502
+
+    override val FLOAT_MAX_POSITIVE = Mflpt5.FLOAT_MAX_POSITIVE
+    override val FLOAT_MAX_NEGATIVE = Mflpt5.FLOAT_MAX_NEGATIVE
+    override val FLOAT_MEM_SIZE = Mflpt5.FLOAT_MEM_SIZE
+    override val PROGRAM_LOAD_ADDRESS = 0x0401u
+
+    override val BSSHIGHRAM_START = 0u
+    override val BSSHIGHRAM_END = 0u
+    override val BSSGOLDENRAM_START = 0u
+    override val BSSGOLDENRAM_END = 0u
+
+    override lateinit var zeropage: Zeropage
+    override lateinit var golden: GoldenRam
+
+    override fun getFloatAsmBytes(num: Number) = Mflpt5.fromNumber(num).makeFloatFillAsm()
+
+    override fun convertFloatToBytes(num: Double): List<UByte> {
+        val m5 = Mflpt5.fromNumber(num)
+        return listOf(m5.b0, m5.b1, m5.b2, m5.b3, m5.b4)
+    }
+
+    override fun convertBytesToFloat(bytes: List<UByte>): Double {
+        require(bytes.size==5) { "need 5 bytes" }
+        val m5 = Mflpt5(bytes[0], bytes[1], bytes[2], bytes[3], bytes[4])
+        return m5.toDouble()
+    }
+
+    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
+        if(selectedEmulator!=1) {
+            System.err.println("The pet target only supports the main emulator (Vice).")
+            return
+        }
+
+        println("\nStarting PET emulator...")
+        val viceMonlist = C64Target.viceMonListName(programNameWithPath.toString())
+        val cmdline = listOf("xpet", "-model", "4032", "-ramsize", "32", "-videosize", "40", "-silent", "-moncommands", viceMonlist,
+                "-autostartprgmode", "1", "-autostart-warp", "-autostart", "${programNameWithPath}.prg")
+        val processb = ProcessBuilder(cmdline).inheritIO()
+        val process=processb.start()
+        process.waitFor()
+    }
+
+    override fun isIOAddress(address: UInt): Boolean = address in 0xe800u..0xe8ffu
+
+    override fun initializeMemoryAreas(compilerOptions: CompilationOptions) {
+        zeropage = PETZeropage(compilerOptions)
+        // there's no golden ram.
+    }
+
+}
@@ -0,0 +1,59 @@
+package prog8.code.target.pet
+
+import prog8.code.core.CompilationOptions
+import prog8.code.core.InternalCompilerException
+import prog8.code.core.Zeropage
+import prog8.code.core.ZeropageType
+
+
+// reference: http://www.zimmers.net/cbmpics/cbm/PETx/petmem.txt
+
+class PETZeropage(options: CompilationOptions) : Zeropage(options) {
+
+    override val SCRATCH_B1 = 0xb3u      // temp storage for a single byte
+    override val SCRATCH_REG = 0xb4u     // temp storage for a register, must be B1+1
+    override val SCRATCH_W1 = 0xb6u      // temp storage 1 for a word
+    override val SCRATCH_W2 = 0xb8u      // temp storage 2 for a word
+
+    init {
+        if (options.floats) {
+            throw InternalCompilerException("PET target doesn't yet support floating point routines")
+        }
+
+        if (options.floats && options.zeropage !in arrayOf(
+                ZeropageType.FLOATSAFE,
+                ZeropageType.BASICSAFE,
+                ZeropageType.DONTUSE
+            ))
+            throw InternalCompilerException("when floats are enabled, zero page type should be 'floatsafe' or 'basicsafe' or 'dontuse'")
+
+        when (options.zeropage) {
+            ZeropageType.FULL -> {
+                free.addAll(0x00u..0xffu)
+                free.removeAll(listOf(0x8du, 0x8eu, 0x8fu, 0x97u, 0x98u, 0x99u, 0x9au, 0x9bu, 0x9eu, 0xa7u, 0xa8u, 0xa9u, 0xaau))        // these are updated/used by IRQ
+            }
+            ZeropageType.KERNALSAFE -> {
+                free.addAll(0x00u..0xffu)
+                free.removeAll(listOf(0x8du, 0x8eu, 0x8fu, 0x97u, 0x98u, 0x99u, 0x9au, 0x9bu, 0x9eu, 0xa7u, 0xa8u, 0xa9u, 0xaau))        // these are updated/used by IRQ
+            }
+            ZeropageType.FLOATSAFE,
+            ZeropageType.BASICSAFE -> {
+                free.addAll(0xb3u..0xbau)       // TODO more?
+            }
+            ZeropageType.DONTUSE -> {
+                free.clear()  // don't use zeropage at all
+            }
+        }
+
+        val distinctFree = free.distinct()
+        free.clear()
+        free.addAll(distinctFree)
+
+        removeReservedFromFreePool()
+        retainAllowed()
+    }
+
+    override fun allocateCx16VirtualRegisters() {
+        TODO("Not known if PET can put the virtual regs in ZP")
+    }
+}
@@ -12,26 +12,42 @@ class VirtualMachineDefinition: IMachineDefinition {

    override val FLOAT_MAX_POSITIVE = Float.MAX_VALUE.toDouble()
    override val FLOAT_MAX_NEGATIVE = -Float.MAX_VALUE.toDouble()
-    override val FLOAT_MEM_SIZE = 4             // 32-bits floating point
+    override val FLOAT_MEM_SIZE = 8             // 64-bits double
    override val PROGRAM_LOAD_ADDRESS = 0u      // not actually used

-    override var ESTACK_LO = 0u                 // not actually used
-    override var ESTACK_HI = 0u                 // not actually used
    override val BSSHIGHRAM_START = 0u          // not actually used
    override val BSSHIGHRAM_END = 0u            // not actually used
+    override val BSSGOLDENRAM_START = 0u        // not actually used
+    override val BSSGOLDENRAM_END = 0u          // not actually used
    override lateinit var zeropage: Zeropage    // not actually used
    override lateinit var golden: GoldenRam     // not actually used

    override fun getFloatAsmBytes(num: Number): String {
        // little endian binary representation
-        val bits = num.toFloat().toBits().toUInt()
-        val hexStr = bits.toString(16).padStart(8, '0')
+        val bits = num.toDouble().toBits().toULong()
+        val hexStr = bits.toString(16).padStart(16, '0')
        val parts = hexStr.chunked(2).map { "\$" + it }
        return parts.joinToString(", ")
    }

-    override fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
-        return listOf("syslib")
+    override fun convertFloatToBytes(num: Double): List<UByte> {
+        val bits = num.toBits().toULong()
+        val hexStr = bits.toString(16).padStart(16, '0')
+        val parts = hexStr.chunked(2).map { it.toInt(16).toUByte() }
+        return parts
+    }
+
+    override fun convertBytesToFloat(bytes: List<UByte>): Double {
+        require(bytes.size==8) { "need 8 bytes" }
+        val b0 = bytes[0].toLong() shl (8*7)
+        val b1 = bytes[1].toLong() shl (8*6)
+        val b2 = bytes[2].toLong() shl (8*5)
+        val b3 = bytes[3].toLong() shl (8*4)
+        val b4 = bytes[4].toLong() shl (8*3)
+        val b5 = bytes[5].toLong() shl (8*2)
+        val b6 = bytes[6].toLong() shl (8*1)
+        val b7 = bytes[7].toLong() shl (8*0)
+        return Double.fromBits(b0 or b1 or b2 or b3 or b4 or b5 or b6 or b7)
    }

    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
@@ -1,15 +1,12 @@
-
 plugins {
    id 'java'
    id 'application'
    id "org.jetbrains.kotlin.jvm"
-    id "io.kotest" version "0.3.9"
 }

 java {
-    toolchain {
-        languageVersion = JavaLanguageVersion.of(javaVersion)
-    }
+    targetCompatibility = JavaLanguageVersion.of(javaVersion)
+    sourceCompatibility = JavaLanguageVersion.of(javaVersion)
 }

 compileKotlin {
@@ -28,18 +25,21 @@ dependencies {
    implementation project(':codeCore')
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
    // implementation "org.jetbrains.kotlin:kotlin-reflect"
-    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.16"
+    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:2.0.0"

-    testImplementation 'io.kotest:kotest-runner-junit5-jvm:5.3.2'
+    testImplementation 'io.kotest:kotest-runner-junit5-jvm:5.9.1'
+    testImplementation 'io.kotest:kotest-framework-datatest:5.9.1'
+    testImplementation 'org.junit.jupiter:junit-jupiter:5.9.2'
+    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
 }

 sourceSets {
    main {
        java {
-            srcDirs = ["${project.projectDir}/src"]
+            srcDir "${project.projectDir}/src"
        }
        resources {
-            srcDirs = ["${project.projectDir}/res"]
+            srcDir "${project.projectDir}/res"
        }
    }
    test {
@@ -14,5 +14,6 @@
    <orderEntry type="library" name="michael.bull.kotlin.result.jvm" level="project" />
    <orderEntry type="library" name="io.kotest.assertions.core.jvm" level="project" />
    <orderEntry type="library" name="io.kotest.runner.junit5.jvm" level="project" />
+    <orderEntry type="library" name="io.kotest.framework.datatest" level="project" />
  </component>
 </module>
@@ -15,21 +15,7 @@ internal fun optimizeAssembly(lines: MutableList<String>, machine: IMachineDefin

    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)
+    var mods = optimizeIncDec(linesByFour)
    if(mods.isNotEmpty()) {
        apply(mods, lines)
        linesByFour = getLinesBy(lines, 4)
@@ -43,7 +29,28 @@ internal fun optimizeAssembly(lines: MutableList<String>, machine: IMachineDefin
        numberOfOptimizations++
    }

-    mods= optimizeJsrRtsAndOtherCombinations(linesByFour)
+    mods = optimizeJsrRtsAndOtherCombinations(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    mods = optimizeUselessPushPopStack(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    mods = optimizeUnneededTempvarInAdd(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    mods = optimizeTSBtoRegularOr(linesByFour)
    if(mods.isNotEmpty()) {
        apply(mods, lines)
        linesByFour = getLinesBy(lines, 4)
@@ -58,15 +65,13 @@ internal fun optimizeAssembly(lines: MutableList<String>, machine: IMachineDefin
        numberOfOptimizations++
    }

-    mods = optimizeSamePointerIndexing(linesByFourteen)
+    mods = optimizeSamePointerIndexingAndUselessBeq(linesByFourteen)
    if(mods.isNotEmpty()) {
        apply(mods, lines)
        linesByFourteen = getLinesBy(lines, 14)
        numberOfOptimizations++
    }

-    // TODO more assembly peephole optimizations
-
    return numberOfOptimizations
 }

@@ -75,61 +80,48 @@ private fun String.isStoreReg() = this.startsWith("sta") || this.startsWith("sty
 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 class Modification(val lineIndex: Int, val remove: Boolean, val replacement: String?, val removeLabel: Boolean=false)

 private fun apply(modifications: List<Modification>, lines: MutableList<String>) {
    for (modification in modifications.sortedBy { it.lineIndex }.reversed()) {
-        if(modification.remove)
-            lines.removeAt(modification.lineIndex)
+        if(modification.remove) {
+            if(modification.removeLabel)
+                lines.removeAt(modification.lineIndex)
+            else {
+                val line = lines[modification.lineIndex]
+                if (line.length < 2 || line[0] == ';' || line.trimStart()[0] == ';')
+                    lines.removeAt(modification.lineIndex)
+                else if (haslabel(line)) {
+                    val label = keeplabel(line)
+                    if (label.isNotEmpty())
+                        lines[modification.lineIndex] = label
+                    else
+                        lines.removeAt(modification.lineIndex)
+                } else lines.removeAt(modification.lineIndex)
+            }
+        }
        else
            lines[modification.lineIndex] = modification.replacement!!
    }
 }

+private fun haslabel(line: String): Boolean {
+    return line.length>1 && line[0]!=';' && (!line[0].isWhitespace() || ':' in line)
+}
+
+private fun keeplabel(line: String): String {
+    if(':' in line)
+        return line.substringBefore(':') + ':'
+    val splits = line.split('\t', ' ', limit=2)
+    return if(splits.size>1) splits[0] + ':' else ""
+}
+
 private fun getLinesBy(lines: MutableList<String>, windowSize: Int) =
 // all lines (that aren't empty or comments) in sliding windows of certain size
-        lines.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
-}
+        lines.asSequence().withIndex().filter { it.value.isNotBlank() && !it.value.trimStart().startsWith(';') }.windowed(windowSize, partialWindows = false)

 private fun optimizeSameAssignments(
-    linesByFourteen: List<List<IndexedValue<String>>>,
+    linesByFourteen: Sequence<List<IndexedValue<String>>>,
    machine: IMachineDefinition,
    symbolTable: SymbolTable
 ): List<Modification> {
@@ -311,26 +303,15 @@ private fun optimizeSameAssignments(
        /*
        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, symbolTable)
-                    if(address==null || !machine.isIOAddress(address)) {
-                        overlappingMods = true
-                        mods.add(Modification(lines[0].index, true, null))
-                    }
-                }
-            }
-        }
+        However, this cannot be done relyably because 'A' could be a constant symbol referring to an I/O address.
+        We can't see that here and would otherwise delete valid double stores.
+        */
    }

    return mods
 }

-private fun optimizeSamePointerIndexing(linesByFourteen: List<List<IndexedValue<String>>>): List<Modification> {
+private fun optimizeSamePointerIndexingAndUselessBeq(linesByFourteen: Sequence<List<IndexedValue<String>>>): List<Modification> {

    // Optimize same pointer indexing where for instance we load and store to the same ptr index in Y
    // if Y isn't modified in between we can omit the second LDY:
@@ -367,33 +348,59 @@ private fun optimizeSamePointerIndexing(linesByFourteen: List<List<IndexedValue<
                mods.add(Modification(lines[4].index, true, null))
            }
        }
+
+
+        /*
+    beq  +
+    lda  #1
+
+[ optional:  label_xxxx_shortcut   line here]
+    beq  label_xxxx_shortcut   /  bne label_xxxx_shortcut
+or *_afterif labels.
+
+This gets generated after certain if conditions, and only the branch instruction is needed in these cases.
+         */
+
+        if(first=="beq  +" && second=="lda  #1" && third=="+") {
+            if((fourth.startsWith("beq  label_") || fourth.startsWith("bne  label_")) &&
+                (fourth.endsWith("_shortcut") || fourth.endsWith("_afterif") || fourth.endsWith("_shortcut:") || fourth.endsWith("_afterif:"))) {
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, true, null))
+                mods.add(Modification(lines[2].index, true, null))
+            }
+            else if(fourth.startsWith("label_") && (fourth.endsWith("_shortcut") || fourth.endsWith("_shortcut:"))) {
+                if((fifth.startsWith("beq  label_") || fifth.startsWith("bne  label_")) &&
+                    (fifth.endsWith("_shortcut") || fifth.endsWith("_afterif") || fifth.endsWith("_shortcut:") || fifth.endsWith("_afterif:"))) {
+                    mods.add(Modification(lines[0].index, true, null))
+                    mods.add(Modification(lines[1].index, true, null))
+                    mods.add(Modification(lines[2].index, true, null))
+                }
+            }
+        }
    }

    return mods
 }

 private fun optimizeStoreLoadSame(
-    linesByFour: List<List<IndexedValue<String>>>,
+    linesByFour: Sequence<List<IndexedValue<String>>>,
    machine: IMachineDefinition,
    symbolTable: SymbolTable
 ): 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()
+        val third = lines[3].value.trimStart()

+        // sta X + lda X,  sty X + ldy X,   stx X + ldx X  -> the second instruction can OFTEN be eliminated
        if ((first.startsWith("sta ") && second.startsWith("lda ")) ||
                (first.startsWith("stx ") && second.startsWith("ldx ")) ||
                (first.startsWith("sty ") && second.startsWith("ldy ")) ||
                (first.startsWith("lda ") && second.startsWith("lda ")) ||
                (first.startsWith("ldy ") && second.startsWith("ldy ")) ||
-                (first.startsWith("ldx ") && second.startsWith("ldx ")) ||
-                (first.startsWith("sta ") && second.startsWith("lda ")) ||
-                (first.startsWith("sty ") && second.startsWith("ldy ")) ||
-                (first.startsWith("stx ") && second.startsWith("ldx "))
+                (first.startsWith("ldx ") && 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
@@ -430,15 +437,21 @@ private fun optimizeStoreLoadSame(
        } 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"))
+        }
+
+
+        // lda X + sta X,  ldy X + sty X,   ldx X + stx X  -> the second instruction can be eliminated
+        if ((first.startsWith("lda ") && second.startsWith("sta ")) ||
+            (first.startsWith("ldx ") && second.startsWith("stx ")) ||
+            (first.startsWith("ldy ") && second.startsWith("sty "))
+        ) {
+            val firstLoc = first.substring(4).trimStart()
+            val secondLoc = second.substring(4).trimStart()
+            if (firstLoc == secondLoc)
+                mods.add(Modification(lines[2].index, true, null))
        }
    }
    return mods
@@ -469,7 +482,7 @@ private fun getAddressArg(line: String, symbolTable: SymbolTable): UInt? {
    }
 }

-private fun optimizeIncDec(linesByFour: List<List<IndexedValue<String>>>): List<Modification> {
+private fun optimizeIncDec(linesByFour: Sequence<List<IndexedValue<String>>>): List<Modification> {
    // sometimes, iny+dey / inx+dex / dey+iny / dex+inx sequences are generated, these can be eliminated.
    val mods = mutableListOf<Modification>()
    for (lines in linesByFour) {
@@ -486,19 +499,23 @@ private fun optimizeIncDec(linesByFour: List<List<IndexedValue<String>>>): List<
            mods.add(Modification(lines[0].index, true, null))
            mods.add(Modification(lines[1].index, true, null))
        }
+
    }
    return mods
 }

-private fun optimizeJsrRtsAndOtherCombinations(linesByFour: List<List<IndexedValue<String>>>): List<Modification> {
+private fun optimizeJsrRtsAndOtherCombinations(linesByFour: Sequence<List<IndexedValue<String>>>): List<Modification> {
    // jsr Sub + rts -> jmp Sub
    // rts + jmp -> remove jmp
    // rts + bxx -> remove bxx
+    // lda  + cmp #0 -> remove cmp,  same for cpy and cpx.
+    // and some other optimizations.

    val mods = mutableListOf<Modification>()
    for (lines in linesByFour) {
        val first = lines[0].value
        val second = lines[1].value
+        val third = lines[2].value
        if ((" jsr" in first || "\tjsr" in first ) && (" rts" in second || "\trts" in second)) {
            mods += Modification(lines[0].index, false, lines[0].value.replace("jsr", "jmp"))
            mods += Modification(lines[1].index, true, null)
@@ -525,6 +542,207 @@ private fun optimizeJsrRtsAndOtherCombinations(linesByFour: List<List<IndexedVal
            else if (" bvc" in second || "\tbvc" in second)
                mods += Modification(lines[1].index, true, null)
        }
+
+        if (!haslabel(second)) {
+            if ((" lda" in first || "\tlda" in first) && (" cmp  #0" in second || "\tcmp  #0" in second) ||
+                (" ldx" in first || "\tldx" in first) && (" cpx  #0" in second || "\tcpx  #0" in second) ||
+                (" ldy" in first || "\tldy" in first) && (" cpy  #0" in second || "\tcpy  #0" in second)
+            ) {
+                mods.add(Modification(lines[1].index, true, null))
+            }
+            else if(" cmp  #0" in second || "\tcmp  #0" in second) {
+                // there are many instructions that modify A and set the bits...
+                for(instr in arrayOf("lda", "ora", "and", "eor", "adc", "sbc", "asl", "cmp", "inc  a", "lsr", "pla", "rol", "ror", "txa", "tya")) {
+                    if(" $instr" in first || "\t$instr" in first) {
+                        mods.add(Modification(lines[1].index, true, null))
+                    }
+                }
+            }
+        }
+
+        /*
+    LDA NUM1
+    CMP NUM2
+    BCC LABEL
+    BEQ LABEL
+
+(or something similar) which branches to LABEL when NUM1 <= NUM2. (In this case NUM1 and NUM2 are unsigned numbers.) However, consider the following sequence:
+
+    LDA NUM2
+    CMP NUM1
+    BCS LABEL
+         */
+        val tfirst = first.trimStart()
+        val tsecond = second.trimStart()
+        val tthird = lines[2].value.trimStart()
+        val tfourth = lines[3].value.trimStart()
+        if(tfirst.startsWith("lda") && tsecond.startsWith("cmp") && tthird.startsWith("bcc") && tfourth.startsWith("beq")) {
+            val label = tthird.substring(4)
+            if(label==tfourth.substring(4)) {
+                mods += Modification(lines[0].index, false, "  lda  ${tsecond.substring(4)}")
+                mods += Modification(lines[1].index, false, "  cmp  ${tfirst.substring(4)}")
+                mods += Modification(lines[2].index, false, "  bcs  $label")
+                mods += Modification(lines[3].index, true, null)
+            }
+        }
+
+
+        fun sameLabel(branchInstr: String, jumpInstr: String, labelInstr: String): Boolean {
+            if('(' in jumpInstr) return false       // indirect jump cannot be replaced
+            val label = labelInstr.trimEnd().substringBefore(':').substringBefore(' ').substringBefore('\t')
+            val branchLabel = branchInstr.trimStart().substring(3).trim()
+            return label==branchLabel
+        }
+
+        // beq Label + jmp Addr + Label  -> bne Addr
+        if((" jmp" in second || "\tjmp " in second) && haslabel(third)) {
+            if((" beq " in first || "\tbeq " in first) && sameLabel(first, second, third)) {
+                val branch = second.replace("jmp", "bne")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+            else if((" bne " in first || "\tbne " in first) && sameLabel(first, second, third)) {
+                val branch = second.replace("jmp", "beq")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+            else if((" bcc " in first || "\tbcc " in first) && sameLabel(first, second, third)){
+                val branch = second.replace("jmp", "bcs")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+            else if((" bcs " in first || "\tbcs " in first) && sameLabel(first, second, third)) {
+                val branch = second.replace("jmp", "bcc")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+            else if((" bpl " in first || "\tbpl " in first) && sameLabel(first, second, third)) {
+                val branch = second.replace("jmp", "bmi")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+            else if((" bmi " in first || "\tbmi " in first) && sameLabel(first, second, third)) {
+                val branch = second.replace("jmp", "bpl")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+            else if((" bvc " in first || "\tbvc " in first) && sameLabel(first, second, third)) {
+                val branch = second.replace("jmp", "bvs")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+            else if((" bvs " in first || "\tbvs " in first) && sameLabel(first, second, third)) {
+                val branch = second.replace("jmp", "bvc")
+                mods.add(Modification(lines[0].index, true, null))
+                mods.add(Modification(lines[1].index, false, branch))
+            }
+        }
    }
    return mods
 }
+
+private fun optimizeUselessPushPopStack(linesByFour: Sequence<List<IndexedValue<String>>>): List<Modification> {
+    val mods = mutableListOf<Modification>()
+
+    fun optimize(register: Char, lines: List<IndexedValue<String>>) {
+        if(lines[0].value.trimStart().startsWith("ph$register")) {
+            if(lines[2].value.trimStart().startsWith("pl$register")) {
+                val second = lines[1].value.trimStart().take(6).lowercase()
+                if(register!in second
+                    && !second.startsWith("jsr")
+                    && !second.startsWith("pl")
+                    && !second.startsWith("ph")) {
+                    mods.add(Modification(lines[0].index, true, null))
+                    mods.add(Modification(lines[2].index, true, null))
+                }
+            }
+            else if (lines[3].value.trimStart().startsWith("pl$register")) {
+                val second = lines[1].value.trimStart().take(6).lowercase()
+                val third = lines[2].value.trimStart().take(6).lowercase()
+                if(register !in second && register !in third
+                    && !second.startsWith("jsr") && !third.startsWith("jsr")
+                    && !second.startsWith("pl") && !third.startsWith("pl")
+                    && !second.startsWith("ph") && !third.startsWith("ph")) {
+                    mods.add(Modification(lines[0].index, true, null))
+                    mods.add(Modification(lines[3].index, true, null))
+                }
+            }
+        }
+    }
+
+    for (lines in linesByFour) {
+        optimize('a', lines)
+        optimize('x', lines)
+        optimize('y', lines)
+
+        val first = lines[1].value.trimStart()
+        val second = lines[2].value.trimStart()
+        val third = lines[3].value.trimStart()
+
+        // phy + ldy + pla -> tya + ldy
+        // phx + ldx + pla -> txa + ldx
+        // pha + lda + pla -> nop
+        if(first=="phy" && second.startsWith("ldy ") && third=="pla") {
+            mods.add(Modification(lines[3].index, true, null))
+            mods.add(Modification(lines[1].index, false, "  tya"))
+        }
+        else if(first=="phx" && second.startsWith("ldx ") && third=="pla") {
+            mods.add(Modification(lines[3].index, true, null))
+            mods.add(Modification(lines[1].index, false, "  txa"))
+        }
+        else if(first=="pha" && second.startsWith("lda ") && third=="pla") {
+            mods.add(Modification(lines[1].index, true, null))
+            mods.add(Modification(lines[2].index, true, null))
+            mods.add(Modification(lines[3].index, true, null))
+        }
+    }
+
+
+    return mods
+}
+
+
+private fun optimizeTSBtoRegularOr(linesByFour: Sequence<List<IndexedValue<String>>>): List<Modification> {
+    // Asm peephole:   lda var2 / tsb var1 / lda var1  Replace this with this to save 1 cycle:   lda var1 / ora var2 / sta var1
+    val mods = mutableListOf<Modification>()
+
+    for(lines in linesByFour) {
+        val first = lines[0].value.trimStart()
+        val second = lines[1].value.trimStart()
+        val third = lines[2].value.trimStart()
+        if(first.startsWith("lda") && second.startsWith("tsb") && third.startsWith("lda")) {
+            val operand1 = first.substring(3)
+            val operand2 = second.substring(3)
+            val operand3 = third.substring(3)
+            if(operand1!=operand2 && operand2==operand3) {
+                mods.add(Modification(lines[0].index, false, "  lda  $operand2"))
+                mods.add(Modification(lines[1].index, false, "  ora  $operand1"))
+                mods.add(Modification(lines[2].index, false, "  sta  $operand2"))
+            }
+        }
+    }
+    return mods
+}
+
+private fun optimizeUnneededTempvarInAdd(linesByFour: Sequence<List<IndexedValue<String>>>): List<Modification> {
+    // sequence:  sta  P8ZP_SCRATCH_XX  / lda  something / clc / adc  P8ZP_SCRATCH_XX
+    // this can be performed without the scratch variable:  clc  /  adc  something
+    val mods = mutableListOf<Modification>()
+
+    for(lines in linesByFour) {
+        val first = lines[0].value.trimStart()
+        val second = lines[1].value.trimStart()
+        val third = lines[2].value.trimStart()
+        val fourth = lines[3].value.trimStart()
+        if(first.startsWith("sta  P8ZP_SCRATCH_") && second.startsWith("lda") && third.startsWith("clc") && fourth.startsWith("adc  P8ZP_SCRATCH_") ) {
+            if(fourth.substring(4)==first.substring(4)) {
+                mods.add(Modification(lines[0].index, false, "  clc"))
+                mods.add(Modification(lines[1].index, false, "  adc  ${second.substring(3).trimStart()}"))
+                mods.add(Modification(lines[2].index, true, null))
+                mods.add(Modification(lines[3].index, true, null))
+            }
+        }
+    }
+
+    return mods
+}
@@ -1,9 +1,8 @@
 package prog8.codegen.cpu6502

-import prog8.code.ast.*
+import prog8.code.ast.PtAsmSub
 import prog8.code.core.Cx16VirtualRegisters
 import prog8.code.core.RegisterOrPair
-import prog8.code.core.RegisterOrStatusflag


 fun asmsub6502ArgsEvalOrder(sub: PtAsmSub): List<Int> {
@@ -11,50 +10,19 @@ fun asmsub6502ArgsEvalOrder(sub: PtAsmSub): List<Int> {
    // order is:
    //  1) cx16 virtual word registers,
    //  2) paired CPU registers,
-    //  3) single CPU registers (X last), except A,
+    //  3) single CPU registers (order Y,X,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.withIndex()
    val (cx16regs, args2) = args.partition { it.value.first.registerOrPair in Cx16VirtualRegisters }
    val pairedRegisters = arrayOf(RegisterOrPair.AX, RegisterOrPair.AY, RegisterOrPair.XY)
    val (pairedRegs , args3) = args2.partition { it.value.first.registerOrPair in pairedRegisters }
-    val (regsWithoutA, args4) = args3.partition { it.value.first.registerOrPair != RegisterOrPair.A }
-    val (regA, rest) = args4.partition { it.value.first.registerOrPair != null }
+    val (singleRegs, rest) = args3.partition { it.value.first.registerOrPair != null }

    cx16regs.forEach { order += it.index }
    pairedRegs.forEach { order += it.index }
-    regsWithoutA.forEach {
-        if(it.value.first.registerOrPair != RegisterOrPair.X)
-            order += it.index
-    }
-    regsWithoutA.firstOrNull { it.value.first.registerOrPair==RegisterOrPair.X } ?.let { order += it.index}
+    singleRegs.sortedBy { it.value.first.registerOrPair!!.asCpuRegister() }.asReversed().forEach { order += it.index }
+    require(rest.all { it.value.first.registerOrPair==null && it.value.first.statusflag!=null})
    rest.forEach { order += it.index }
-    regA.forEach { order += it.index }
    require(order.size==sub.parameters.size)
    return order
 }
-
-fun asmsub6502ArgsHaveRegisterClobberRisk(
-    args: List<PtExpression>,
-    params: List<Pair<RegisterOrStatusflag, PtSubroutineParameter>>
-): Boolean {
-    fun isClobberRisk(expr: PtExpression): Boolean {
-        when (expr) {
-            is PtArrayIndexer -> {
-                return params.any {
-                    it.first.registerOrPair in listOf(RegisterOrPair.Y, RegisterOrPair.AY, RegisterOrPair.XY)
-                }
-            }
-            is PtBuiltinFunctionCall -> {
-                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) }
-}
@@ -1,13 +1,8 @@
 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 java.io.File
+import prog8.code.target.C64Target
 import java.nio.file.Path
-import kotlin.io.path.Path
-import kotlin.io.path.isRegularFile


 internal class AssemblyProgram(
@@ -19,28 +14,34 @@ internal class AssemblyProgram(
    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("$name.bin")
-    private val viceMonListFile = outputDir.resolve(viceMonListName(name))
+    private val viceMonListFile = outputDir.resolve(C64Target.viceMonListName(name))
    private val listFile = outputDir.resolve("$name.list")

-    override fun assemble(options: CompilationOptions): Boolean {
+    override fun assemble(options: CompilationOptions, errors: IErrorReporter): Boolean {

        val assemblerCommand: List<String>

        when (compTarget.name) {
-            in setOf("c64", "c128", "cx16") -> {
+            in setOf("c64", "c128", "cx16", "pet32") -> {
                // CBM machines .prg generation.

                // add "-Wlong-branch"  to see warnings about conversion of branch instructions to jumps (default = do this silently)
                val command = mutableListOf("64tass", "--ascii", "--case-sensitive", "--long-branch",
-                    "-Wall", "-Wno-strict-bool", "-Wno-shadow", // "-Werror",
-                    "--dump-labels", "--vice-labels", "--labels=$viceMonListFile", "--no-monitor"
+                    "-Wall", // "-Wno-strict-bool", "-Werror",
+                    "--dump-labels", "--vice-labels", "--labels=$viceMonListFile"
                )

+                if(options.warnSymbolShadowing)
+                    command.add("-Wshadow")
+                else
+                    command.add("-Wno-shadow")
+
                if(options.asmQuiet)
                    command.add("--quiet")

-                if(options.asmListfile)
-                    command.add("--list=$listFile")
+                if(options.asmListfile) {
+                    command.addAll(listOf("--list=$listFile", "--no-monitor"))
+                }

                val outFile = when (options.output) {
                    OutputType.PRG -> {
@@ -64,10 +65,15 @@ internal class AssemblyProgram(

                // TODO are these options okay for atari?
                val command = mutableListOf("64tass", "--ascii", "--case-sensitive", "--long-branch",
-                    "-Wall", "-Wno-strict-bool", "-Wno-shadow", // "-Werror",
+                    "-Wall", // "-Werror", "-Wno-strict-bool"
                    "--no-monitor"
                )

+                if(options.warnSymbolShadowing)
+                    command.add("-Wshadow")
+                else
+                    command.add("-Wno-shadow")
+
                if(options.asmQuiet)
                    command.add("--quiet")

@@ -129,18 +135,3 @@ internal class AssemblyProgram(
        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)
-    }
-}
@@ -1,907 +0,0 @@
-package prog8.codegen.cpu6502
-
-import prog8.code.ast.*
-import prog8.code.core.*
-import kotlin.math.absoluteValue
-
-internal class ExpressionsAsmGen(private val program: PtProgram,
-                                 private val asmgen: AsmGen6502Internal,
-                                 private val allocator: VariableAllocator) {
-
-    @Deprecated("avoid calling this as it generates slow evalstack based code")
-    internal fun translateExpression(expression: PtExpression) {
-        if (this.asmgen.options.slowCodegenWarnings) {
-            asmgen.errors.warn("slow stack evaluation used for expression", expression.position)
-        }
-        translateExpressionInternal(expression)
-    }
-
-
-    // the rest of the methods are all PRIVATE
-
-
-    private fun translateExpressionInternal(expression: PtExpression) {
-
-        when(expression) {
-            is PtPrefix -> translateExpression(expression)
-            is PtBinaryExpression -> translateExpression(expression)
-            is PtArrayIndexer -> translateExpression(expression)
-            is PtTypeCast -> translateExpression(expression)
-            is PtAddressOf -> translateExpression(expression)
-            is PtMemoryByte -> asmgen.translateDirectMemReadExpressionToRegAorStack(expression, true)
-            is PtNumber -> translateExpression(expression)
-            is PtIdentifier -> translateExpression(expression)
-            is PtFunctionCall -> translateFunctionCallResultOntoStack(expression)
-            is PtBuiltinFunctionCall -> asmgen.translateBuiltinFunctionCallExpression(expression, true, null)
-            is PtContainmentCheck -> throw AssemblyError("containment check as complex expression value is not supported")
-            is PtArray, is PtString -> throw AssemblyError("no asm gen for string/array literal value assignment - should have been replaced by a variable")
-            is PtRange -> throw AssemblyError("range expression should have been changed into array values")
-            is PtMachineRegister -> throw AssemblyError("machine register ast node should not occur in 6502 codegen it is for IR code")
-            else -> TODO("missing expression asmgen for $expression")
-        }
-    }
-
-    private fun translateFunctionCallResultOntoStack(call: PtFunctionCall) {
-        // only for use in nested expression evaluation
-
-        val symbol = asmgen.symbolTable.lookup(call.name)
-        val sub = symbol!!.astNode as IPtSubroutine
-        asmgen.saveXbeforeCall(call)
-        asmgen.translateFunctionCall(call)
-        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: List<Pair<RegisterOrStatusflag, DataType>> = sub.returnsWhatWhere()
-        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: PtTypeCast) {
-        translateExpressionInternal(typecast.value)
-        when(typecast.value.type) {
-            DataType.UBYTE, DataType.BOOL -> {
-                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: PtAddressOf) {
-        val name = asmgen.asmVariableName(expr.identifier)
-        asmgen.out("  lda  #<$name |  sta  P8ESTACK_LO,x |  lda  #>$name  |  sta  P8ESTACK_HI,x  | dex")
-    }
-
-    private fun translateExpression(expr: PtNumber) {
-        when(expr.type) {
-            DataType.UBYTE, DataType.BYTE -> asmgen.out(" lda  #${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: PtIdentifier) {
-        val varname = asmgen.asmVariableName(expr)
-        when(expr.type) {
-            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: PtBinaryExpression) {
-        // Uses evalstack to evaluate the given expression.  THIS IS SLOW AND SHOULD BE AVOIDED!
-        val leftDt = expr.left.type
-        val rightDt = expr.right.type
-        // see if we can apply some optimized routines still
-        when(expr.operator) {
-            "+" -> {
-                if(leftDt in IntegerDatatypes && rightDt in IntegerDatatypes) {
-                    val leftVal = expr.left.asConstInteger()
-                    val rightVal = expr.right.asConstInteger()
-                    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.asConstInteger()
-                    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.asConstInteger()
-                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_$left")
-                        }
-                        else -> throw AssemblyError("weird type")
-                    }
-                    return
-                }
-            }
-            "<<" -> {
-                val amount = expr.right.asConstInteger()
-                if(amount!=null) {
-                    translateExpressionInternal(expr.left)
-                    if (leftDt in ByteDatatypes) {
-                        if (amount <= 2)
-                            repeat(amount) { asmgen.out("  asl  P8ESTACK_LO+1,x") }
-                        else {
-                            asmgen.out("  lda  P8ESTACK_LO+1,x")
-                            repeat(amount) { asmgen.out("  asl  a") }
-                            asmgen.out("  sta  P8ESTACK_LO+1,x")
-                        }
-                    } else {
-                        var left = amount
-                        while (left >= 7) {
-                            asmgen.out(" jsr  math.shift_left_w_7")
-                            left -= 7
-                        }
-                        if (left in 0..2)
-                            repeat(left) { asmgen.out("  asl  P8ESTACK_LO+1,x |  rol  P8ESTACK_HI+1,x") }
-                        else
-                            asmgen.out(" jsr  math.shift_left_w_$left")
-                    }
-                    return
-                }
-            }
-            "*" -> {
-                if(leftDt in IntegerDatatypes && rightDt in IntegerDatatypes) {
-                    val leftVar = expr.left as? PtIdentifier
-                    val rightVar = expr.right as? PtIdentifier
-                    if(leftVar!=null && rightVar!=null && leftVar==rightVar)
-                        return translateSquared(leftVar, leftDt)
-                }
-
-                val value = expr.right as? PtNumber
-                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.asConstInteger()
-                    if(rightVal!=null && rightVal==2) {
-                        translateExpressionInternal(expr.left)
-                        when (leftDt) {
-                            DataType.UBYTE -> {
-                                asmgen.out("  lsr  P8ESTACK_LO+1,x")
-                            }
-                            DataType.UWORD -> {
-                                asmgen.out("  lsr  P8ESTACK_HI+1,x |  ror  P8ESTACK_LO+1,x")
-                            }
-                            DataType.BYTE -> {
-                                // signed divide using shift needs adjusting of negative value to get correct rounding towards zero
-                                asmgen.out("""
-                                    lda  P8ESTACK_LO+1,x
-                                    bpl  +
-                                    inc  P8ESTACK_LO+1,x
-                                    lda  P8ESTACK_LO+1,x
-+                                   asl  a
-                                    ror  P8ESTACK_LO+1,x""")
-                            }
-                            DataType.WORD -> {
-                                // signed divide using shift needs adjusting of negative value to get correct rounding towards zero
-                                asmgen.out("""
-                                    lda  P8ESTACK_HI+1,x
-                                    bpl  ++
-                                    inc  P8ESTACK_LO+1,x
-                                    bne  +
-                                    inc  P8ESTACK_HI+1,x
-+                                   lda  P8ESTACK_HI+1,x
-+                                   asl  a
-                                    ror  P8ESTACK_HI+1,x
-                                    ror  P8ESTACK_LO+1,x""")
-                            }
-                            else -> throw AssemblyError("weird dt")
-                        }
-                        return
-                    }
-                }
-            }
-            in ComparisonOperators -> {
-                if(leftDt in NumericDatatypes && rightDt in NumericDatatypes) {
-                    val rightVal = expr.right.asConstInteger()
-                    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: PtExpression, dt: DataType, operator: String) {
-        if(expr.isSimple()) {
-            if(operator=="!=") {
-                when (dt) {
-                    in ByteDatatypes -> {
-                        asmgen.assignExpressionToRegister(expr, RegisterOrPair.A, dt == DataType.BYTE)
-                        asmgen.out("""
-                            beq  +
-                            lda  #1
-+                           sta  P8ESTACK_LO,x
-                            dex""")
-                        return
-                    }
-                    in WordDatatypes -> {
-                        asmgen.assignExpressionToRegister(expr, RegisterOrPair.AY, dt == DataType.WORD)
-                        asmgen.out("""
-                            sty  P8ZP_SCRATCH_B1 
-                            ora  P8ZP_SCRATCH_B1
-                            beq  +
-                            lda  #1
-+                           sta  P8ESTACK_LO,x
-                            dex""")
-                        return
-                    }
-                    DataType.FLOAT -> {
-                        asmgen.assignExpressionToRegister(expr, RegisterOrPair.FAC1, true)
-                        asmgen.out("""
-                            jsr  floats.SIGN
-                            sta  P8ESTACK_LO,x
-                            dex""")
-                        return
-                    }
-                    else -> {}
-                }
-            }
-            /* operator == is not worth it to special case, the code is mostly larger */
-        }
-        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(PtNumber.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(PtNumber.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: PtIdentifier, 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: PtPrefix) {
-        translateExpressionInternal(expr.value)
-        when(expr.operator) {
-            "+" -> {}
-            "-" -> {
-                when(expr.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(expr.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")
-                }
-            }
-            else -> throw AssemblyError("invalid prefix operator ${expr.operator}")
-        }
-    }
-
-    private fun translateExpression(arrayExpr: PtArrayIndexer) {
-        val elementDt = arrayExpr.type
-        val arrayVarName = asmgen.asmVariableName(arrayExpr.variable)
-
-        if(arrayExpr.variable.type==DataType.UWORD) {
-            // indexing a pointer var instead of a real array or string
-            if(elementDt !in ByteDatatypes)
-                throw AssemblyError("non-array var indexing requires bytes dt")
-            if(arrayExpr.index.type != DataType.UBYTE)
-                throw AssemblyError("non-array var indexing requires bytes index")
-            asmgen.loadScaledArrayIndexIntoRegister(arrayExpr, elementDt, CpuRegister.Y)
-            if(asmgen.isZpVar(arrayExpr.variable)) {
-                asmgen.out("  lda  ($arrayVarName),y")
-            } else {
-                asmgen.out("  lda  $arrayVarName |  sta  P8ZP_SCRATCH_W1 |  lda  $arrayVarName+1 |  sta  P8ZP_SCRATCH_W1+1")
-                asmgen.out("  lda  (P8ZP_SCRATCH_W1),y")
-            }
-            asmgen.out("  sta  P8ESTACK_LO,x |  dex")
-            return
-        }
-
-        val constIndexNum = arrayExpr.index.asConstInteger()
-        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")
-            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")
-            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")
-            "%", "<<", ">>", "&", "^", "|" -> throw AssemblyError("requires integer datatype")
-            else -> throw AssemblyError("invalid operator $operator")
-        }
-    }
-
-    private fun translateCompareStrings(s1: PtExpression, operator: String, s2: PtExpression) {
-        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")
-    }
-}
@@ -6,26 +6,6 @@ import prog8.code.ast.PtSub
 import prog8.code.core.*


-internal fun IPtSubroutine.regXasResult(): Boolean =
-    (this is PtAsmSub) && this.returns.any { it.first.registerOrPair in arrayOf(RegisterOrPair.X, RegisterOrPair.AX, RegisterOrPair.XY) }
-
-internal fun IPtSubroutine.shouldSaveX(): Boolean =
-    this.regXasResult() || (this is PtAsmSub && (CpuRegister.X in this.clobbers || regXasParam()))
-
-internal fun PtAsmSub.regXasParam(): Boolean =
-    parameters.any { it.first.registerOrPair in arrayOf(RegisterOrPair.X, RegisterOrPair.AX, RegisterOrPair.XY) }
-
-internal class KeepAresult(val saveOnEntry: Boolean, val saveOnReturn: Boolean)
-
-internal fun PtAsmSub.shouldKeepA(): KeepAresult {
-    // determine if A's value should be kept when preparing for calling the subroutine, and when returning from it
-
-    // it seems that we never have to save A when calling? will be loaded correctly after setup.
-    // but on return it depends on wether the routine returns something in A.
-    val saveAonReturn = returns.any { it.first.registerOrPair==RegisterOrPair.A || it.first.registerOrPair==RegisterOrPair.AY || it.first.registerOrPair==RegisterOrPair.AX }
-    return KeepAresult(false, saveAonReturn)
-}
-
 internal fun IPtSubroutine.returnsWhatWhere(): List<Pair<RegisterOrStatusflag, DataType>> {
    when(this) {
        is PtAsmSub -> {
@@ -37,7 +17,7 @@ internal fun IPtSubroutine.returnsWhatWhere(): List<Pair<RegisterOrStatusflag, D
                emptyList()
            else {
                val register = when (returntype!!) {
-                    in ByteDatatypes -> RegisterOrStatusflag(RegisterOrPair.A, null)
+                    in ByteDatatypesWithBoolean -> RegisterOrStatusflag(RegisterOrPair.A, null)
                    in WordDatatypes -> RegisterOrStatusflag(RegisterOrPair.AY, null)
                    DataType.FLOAT -> RegisterOrStatusflag(RegisterOrPair.FAC1, null)
                    else -> RegisterOrStatusflag(RegisterOrPair.AY, null)
@@ -51,7 +31,7 @@ internal fun IPtSubroutine.returnsWhatWhere(): List<Pair<RegisterOrStatusflag, D

 internal fun PtSub.returnRegister(): RegisterOrStatusflag? {
    return when(returntype) {
-        in ByteDatatypes -> RegisterOrStatusflag(RegisterOrPair.A, null)
+        in ByteDatatypesWithBoolean -> RegisterOrStatusflag(RegisterOrPair.A, null)
        in WordDatatypes -> RegisterOrStatusflag(RegisterOrPair.AY, null)
        DataType.FLOAT -> RegisterOrStatusflag(RegisterOrPair.FAC1, null)
        null -> null
@@ -1,13 +1,18 @@
 package prog8.codegen.cpu6502

 import com.github.michaelbull.result.fold
-import prog8.code.ast.*
+import prog8.code.StMemVar
+import prog8.code.StStaticVariable
+import prog8.code.ast.PtForLoop
+import prog8.code.ast.PtIdentifier
+import prog8.code.ast.PtRange
 import prog8.code.core.*
 import kotlin.math.absoluteValue

-internal class ForLoopsAsmGen(private val program: PtProgram,
-                              private val asmgen: AsmGen6502Internal,
-                              private val zeropage: Zeropage) {
+internal class ForLoopsAsmGen(
+    private val asmgen: AsmGen6502Internal,
+    private val zeropage: Zeropage
+) {

    internal fun translate(stmt: PtForLoop) {
        val iterableDt = stmt.iterable.type
@@ -32,7 +37,7 @@ internal class ForLoopsAsmGen(private val program: PtProgram,
        val endLabel = asmgen.makeLabel("for_end")
        val modifiedLabel = asmgen.makeLabel("for_modified")
        val modifiedLabel2 = asmgen.makeLabel("for_modifiedb")
-        asmgen.loopEndLabels.push(endLabel)
+        asmgen.loopEndLabels.add(endLabel)
        val stepsize=range.step.asConstInteger()!!

        if(stepsize < -1) {
@@ -43,15 +48,62 @@ internal class ForLoopsAsmGen(private val program: PtProgram,

        when(iterableDt) {
            DataType.ARRAY_B, DataType.ARRAY_UB -> {
-                if (stepsize==1 || stepsize==-1) {
-
+                val varname = asmgen.asmVariableName(stmt.variable)
+                asmgen.assignExpressionToVariable(range.from, varname, ArrayToElementTypes.getValue(iterableDt))
+                if (stepsize==-1 && range.to.asConstInteger()==0) {
+                    // simple loop downto 0 step -1
+                    asmgen.out(loopLabel)
+                    asmgen.translate(stmt.statements)
+                    asmgen.out("""
+                        dec  $varname
+                        lda  $varname
+                        cmp  #255
+                        bne  $loopLabel""")
+                }
+                else if (stepsize==-1 && range.to.asConstInteger()==1) {
+                    // simple loop downto 1 step -1
+                    asmgen.out(loopLabel)
+                    asmgen.translate(stmt.statements)
+                    asmgen.out("""
+                        dec  $varname
+                        bne  $loopLabel""")
+                }
+                else if (stepsize==1 || stepsize==-1) {
                    // bytes array, step 1 or -1

                    val incdec = if(stepsize==1) "inc" else "dec"
                    // loop over byte range via loopvar
-                    val varname = asmgen.asmVariableName(stmt.variable)
-                    asmgen.assignExpressionToVariable(range.from, varname, ArrayToElementTypes.getValue(iterableDt), null)
-                    asmgen.assignExpressionToVariable(range.to, "$modifiedLabel+1", ArrayToElementTypes.getValue(iterableDt), null)
+                    asmgen.assignExpressionToRegister(range.to, RegisterOrPair.A, false)
+                    // pre-check for end already reached
+                    if(iterableDt==DataType.ARRAY_B) {
+                        asmgen.out("  sta  $modifiedLabel+1")
+                        if(stepsize<0) {
+                            asmgen.out("""
+                                clc
+                                sbc  $varname
+                                bvc  +
+                                eor  #${'$'}80
+                               bpl  $endLabel""")
+                        }
+                        else
+                            asmgen.out("""
+                                sec
+                                sbc  $varname
+                                bvc  +
+                                eor  #${'$'}80
+                               bmi  $endLabel""")
+                    } else {
+                        if(stepsize<0) {
+                            asmgen.out("""
+                                cmp  $varname
+                                beq  +
+                                bcs  $endLabel
+""")
+                        }
+                        else
+                            asmgen.out("  cmp  $varname  |  bcc  $endLabel")
+                        asmgen.out("  sta  $modifiedLabel+1")
+                    }
                    asmgen.out(loopLabel)
                    asmgen.translate(stmt.statements)
                    asmgen.out("""
@@ -67,9 +119,35 @@ $modifiedLabel          cmp  #0         ; modified
                    // bytes, step >= 2 or <= -2

                    // loop over byte range via loopvar
-                    val varname = asmgen.asmVariableName(stmt.variable)
-                    asmgen.assignExpressionToVariable(range.from, varname, ArrayToElementTypes.getValue(iterableDt), null)
-                    asmgen.assignExpressionToVariable(range.to, "$modifiedLabel+1", ArrayToElementTypes.getValue(iterableDt), null)
+                    asmgen.assignExpressionToRegister(range.to, RegisterOrPair.A, false)
+                    // pre-check for end already reached
+                    if(iterableDt==DataType.ARRAY_B) {
+                        asmgen.out("  sta  $modifiedLabel+1")
+                        if(stepsize<0)
+                            asmgen.out("""
+                                clc
+                                sbc  $varname
+                                bvc  +
+                                eor  #${'$'}80
+                               bpl  $endLabel""")
+                        else
+                            asmgen.out("""
+                                sec
+                                sbc  $varname
+                                bvc  +
+                                eor  #${'$'}80
+                               bmi  $endLabel""")
+                    } else {
+                        if(stepsize<0)
+                            asmgen.out("""
+                                cmp  $varname
+                                beq  +
+                                bcs  $endLabel
+""")
+                        else
+                            asmgen.out("  cmp  $varname  |  bcc  $endLabel")
+                        asmgen.out("  sta  $modifiedLabel+1")
+                    }
                    asmgen.out(loopLabel)
                    asmgen.translate(stmt.statements)
                    if(stepsize>0) {
@@ -94,56 +172,85 @@ $modifiedLabel              cmp  #0     ; modified
                }
            }
            DataType.ARRAY_W, DataType.ARRAY_UW -> {
-                when {
-
+                val varname = asmgen.asmVariableName(stmt.variable)
+                assignLoopvarWord(stmt, range)
+                if(stepsize==-1 && range.to.asConstInteger()==0) {
+                    // simple loop downto 0 step -1 (words)
+                    asmgen.out(loopLabel)
+                    asmgen.translate(stmt.statements)
+                    asmgen.out("""
+                        lda  $varname
+                        bne  ++
+                        lda  $varname+1
+                        beq  $endLabel
+                       lda  $varname
+                        bne  +
+                        dec  $varname+1
+                       dec  $varname""")
+                    asmgen.jmp(loopLabel)
+                    asmgen.out(endLabel)
+                }
+                else if (stepsize==-1 && range.to.asConstInteger()==1) {
+                    // simple loop downto 1 step -1 (words)
+                    asmgen.out(loopLabel)
+                    asmgen.translate(stmt.statements)
+                    asmgen.out("""
+                        lda  $varname
+                        cmp  #1
+                        bne  +
+                        lda  $varname+1
+                        beq  $endLabel
+                       lda  $varname
+                        bne  +
+                        dec  $varname+1
+                       dec  $varname""")
+                    asmgen.jmp(loopLabel)
+                    asmgen.out(endLabel)
+                }
+                else if (stepsize == 1 || stepsize == -1) {
                    // words, step 1 or -1
-
-                    stepsize == 1 || stepsize == -1 -> {
-                        val varname = asmgen.asmVariableName(stmt.variable)
-                        assignLoopvar(stmt, range)
-                        asmgen.assignExpressionToRegister(range.to, RegisterOrPair.AY)
-                        asmgen.out("""
-                            sty  $modifiedLabel+1
-                            sta  $modifiedLabel2+1
+                    asmgen.assignExpressionToRegister(range.to, RegisterOrPair.AY)
+                    precheckFromToWord(iterableDt, stepsize, varname, endLabel)
+                    asmgen.out("""
+                sty  $modifiedLabel+1
+                sta  $modifiedLabel2+1
 $loopLabel""")
-                        asmgen.translate(stmt.statements)
-                        asmgen.out("""
+                    asmgen.translate(stmt.statements)
+                    asmgen.out("""
                lda  $varname+1
 $modifiedLabel  cmp  #0    ; modified 
                bne  +
                lda  $varname
 $modifiedLabel2 cmp  #0    ; modified 
                beq  $endLabel""")
-                        if(stepsize==1) {
-                            asmgen.out("""
+                    if(stepsize==1) {
+                        asmgen.out("""
 +               inc  $varname
                bne  $loopLabel
                inc  $varname+1""")
-                            asmgen.jmp(loopLabel)
-                        } else {
-                            asmgen.out("""
+                        asmgen.jmp(loopLabel)
+                    } else {
+                        asmgen.out("""
 +               lda  $varname
                bne  +
                dec  $varname+1
 +               dec  $varname""")
-                            asmgen.jmp(loopLabel)
-                        }
-                        asmgen.out(endLabel)
+                        asmgen.jmp(loopLabel)
                    }
-                    stepsize > 0 -> {
-
-                        // (u)words, step >= 2
-                        val varname = asmgen.asmVariableName(stmt.variable)
-                        assignLoopvar(stmt, range)
-                        asmgen.assignExpressionToRegister(range.to, RegisterOrPair.AY)
-                        asmgen.out("""
-                            sty  $modifiedLabel+1
-                            sta  $modifiedLabel2+1
+                    asmgen.out(endLabel)
+                }
+                else if (stepsize > 0) {
+                    // (u)words, step >= 2
+                    asmgen.assignExpressionToRegister(range.to, RegisterOrPair.AY)
+                    precheckFromToWord(iterableDt, stepsize, varname, endLabel)
+                    asmgen.out("""
+                sty  $modifiedLabel+1
+                sta  $modifiedLabel2+1
 $loopLabel""")
-                        asmgen.translate(stmt.statements)
+                    asmgen.translate(stmt.statements)

-                        if (iterableDt == DataType.ARRAY_UW) {
-                            asmgen.out("""
+                    if (iterableDt == DataType.ARRAY_UW) {
+                        asmgen.out("""
                lda  $varname
                clc
                adc  #<$stepsize
@@ -159,8 +266,8 @@ $modifiedLabel2 lda  #0     ; modified
                bcc  $endLabel
                bcs  $loopLabel
 $endLabel""")
-                        } else {
-                            asmgen.out("""
+                    } else {
+                        asmgen.out("""
                lda  $varname
                clc
                adc  #<$stepsize
@@ -176,47 +283,29 @@ $modifiedLabel  lda  #0   ; modified
                eor  #$80
 +               bpl  $loopLabel                
 $endLabel""")
-                        }
                    }
-                    else -> {
+                }
+                else {

-                        // (u)words, step <= -2
-                        val varname = asmgen.asmVariableName(stmt.variable)
-                        assignLoopvar(stmt, range)
-                        asmgen.assignExpressionToRegister(range.to, RegisterOrPair.AY)
-                        asmgen.out("""
-                            sty  $modifiedLabel+1
-                            sta  $modifiedLabel2+1
+                    // (u)words, step <= -2
+                    asmgen.assignExpressionToRegister(range.to, RegisterOrPair.AY)
+                    precheckFromToWord(iterableDt, stepsize, varname, endLabel)
+                    asmgen.out("""
+                sty  $modifiedLabel+1
+                sta  $modifiedLabel2+1
 $loopLabel""")
-                        asmgen.translate(stmt.statements)
+                    asmgen.translate(stmt.statements)

-                        if(iterableDt==DataType.ARRAY_UW) {
-                            asmgen.out("""
+                    asmgen.out("""
                lda  $varname
                sec
                sbc  #<${stepsize.absoluteValue}
                sta  $varname
+                tax
                lda  $varname+1
                sbc  #>${stepsize.absoluteValue}
                sta  $varname+1
-$modifiedLabel  cmp  #0    ; modified                
-                bcc  $endLabel
-                bne  $loopLabel
-                lda  $varname
-$modifiedLabel2 cmp  #0    ; modified 
-                bcs  $loopLabel
-$endLabel""")
-                        } else {
-                            asmgen.out("""
-                lda  $varname
-                sec
-                sbc  #<${stepsize.absoluteValue}
-                sta  $varname
-                pha
-                lda  $varname+1
-                sbc  #>${stepsize.absoluteValue}
-                sta  $varname+1
-                pla
+                txa
 $modifiedLabel2 cmp  #0    ; modified 
                lda  $varname+1
 $modifiedLabel  sbc  #0    ; modified
@@ -224,27 +313,73 @@ $modifiedLabel  sbc  #0    ; modified
                eor  #$80
 +               bpl  $loopLabel                
 $endLabel""")
-                        }
-                    }
                }
            }
            else -> throw AssemblyError("range expression can only be byte or word")
        }

-        asmgen.loopEndLabels.pop()
+        asmgen.loopEndLabels.removeLast()
+    }
+
+    private fun precheckFromToWord(iterableDt: DataType, stepsize: Int, fromVar: String, endLabel: String) {
+        // pre-check for end already reached.
+        // 'to' is in AY, do NOT clobber this!
+        if(iterableDt==DataType.ARRAY_W) {
+            if(stepsize<0)
+                asmgen.out("""
+                    sta  P8ZP_SCRATCH_W2        ; to
+                    sty  P8ZP_SCRATCH_W2+1      ; to
+                    lda  $fromVar
+	                cmp  P8ZP_SCRATCH_W2
+                    lda  $fromVar+1
+	                sbc  P8ZP_SCRATCH_W2+1
+	                bvc  +
+	                eor  #${'$'}80
+           		bmi  $endLabel
+                    lda  P8ZP_SCRATCH_W2
+                    ldy  P8ZP_SCRATCH_W2+1""")
+            else
+                asmgen.out("""
+                    sta  P8ZP_SCRATCH_REG
+	                cmp  $fromVar
+	                tya
+	                sbc  $fromVar+1
+	                bvc  +
+	                eor  #${'$'}80
+           		bmi  $endLabel
+                    lda  P8ZP_SCRATCH_REG""")
+        } else {
+            if(stepsize<0)
+                asmgen.out("""
+                    cpy  $fromVar+1
+                    beq  +
+                    bcc  ++
+                    bcs  $endLabel
+                   cmp  $fromVar
+                    bcc  +
+                    beq  +
+                    bne  $endLabel
+""")
+            else
+                asmgen.out("""
+                	cpy  $fromVar+1
+	                bcc  $endLabel
+	                bne  +
+	                cmp  $fromVar
+	                bcc  $endLabel
+""")
+        }
    }

    private fun translateForOverIterableVar(stmt: PtForLoop, iterableDt: DataType, ident: PtIdentifier) {
        val loopLabel = asmgen.makeLabel("for_loop")
        val endLabel = asmgen.makeLabel("for_end")
-        asmgen.loopEndLabels.push(endLabel)
+        asmgen.loopEndLabels.add(endLabel)
        val iterableName = asmgen.asmVariableName(ident)
-        val symbol = asmgen.symbolTable.lookup(ident.name)
-        val decl = symbol!!.astNode as IPtVariable
-        val numElements = when(decl) {
-            is PtConstant -> throw AssemblyError("length of non-array requested")
-            is PtMemMapped -> decl.arraySize
-            is PtVariable -> decl.arraySize
+        val numElements = when(val symbol = asmgen.symbolTable.lookup(ident.name)) {
+            is StStaticVariable -> symbol.length!!
+            is StMemVar -> symbol.length!!
+            else -> 0
        }
        when(iterableDt) {
            DataType.STR -> {
@@ -264,7 +399,7 @@ $loopLabel          lda  ${65535.toHex()}       ; modified
                    bne  $loopLabel
 $endLabel""")
            }
-            DataType.ARRAY_UB, DataType.ARRAY_B -> {
+            DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_BOOL -> {
                val indexVar = asmgen.makeLabel("for_index")
                asmgen.out("""
                    ldy  #0
@@ -272,7 +407,7 @@ $loopLabel          sty  $indexVar
                    lda  $iterableName,y
                    sta  ${asmgen.asmVariableName(stmt.variable)}""")
                asmgen.translate(stmt.statements)
-                if(numElements!!<=255u) {
+                if(numElements<=255) {
                    asmgen.out("""
                        ldy  $indexVar
                        iny
@@ -287,11 +422,11 @@ $loopLabel          sty  $indexVar
                        bne  $loopLabel
                        beq  $endLabel""")
                }
-                if(numElements>=16u) {
+                if(numElements>=16) {
                    // allocate index var on ZP if possible
                    val result = zeropage.allocate(indexVar, DataType.UBYTE, null, stmt.position, asmgen.errors)
                    result.fold(
-                        success = { (address,_)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
+                        success = { (address, _, _)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
                        failure = { asmgen.out("$indexVar    .byte  0") }
                    )
                } else {
@@ -300,7 +435,7 @@ $loopLabel          sty  $indexVar
                asmgen.out(endLabel)
            }
            DataType.ARRAY_W, DataType.ARRAY_UW -> {
-                val length = numElements!! * 2u
+                val length = numElements * 2
                val indexVar = asmgen.makeLabel("for_index")
                val loopvarName = asmgen.asmVariableName(stmt.variable)
                asmgen.out("""
@@ -311,7 +446,7 @@ $loopLabel          sty  $indexVar
                    lda  $iterableName+1,y
                    sta  $loopvarName+1""")
                asmgen.translate(stmt.statements)
-                if(length<=127u) {
+                if(length<=127) {
                    asmgen.out("""
                        ldy  $indexVar
                        iny
@@ -328,11 +463,49 @@ $loopLabel          sty  $indexVar
                        bne  $loopLabel
                        beq  $endLabel""")
                }
-                if(length>=16u) {
+                if(length>=16) {
                    // allocate index var on ZP if possible
                    val result = zeropage.allocate(indexVar, DataType.UBYTE, null, stmt.position, asmgen.errors)
                    result.fold(
-                        success = { (address,_)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
+                        success = { (address,_,_)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
+                        failure = { asmgen.out("$indexVar    .byte  0") }
+                    )
+                } else {
+                    asmgen.out("$indexVar    .byte  0")
+                }
+                asmgen.out(endLabel)
+            }
+            DataType.ARRAY_UW_SPLIT, DataType.ARRAY_W_SPLIT -> {
+                val indexVar = asmgen.makeLabel("for_index")
+                val loopvarName = asmgen.asmVariableName(stmt.variable)
+                asmgen.out("""
+                    ldy  #0
+$loopLabel          sty  $indexVar
+                    lda  ${iterableName}_lsb,y
+                    sta  $loopvarName
+                    lda  ${iterableName}_msb,y
+                    sta  $loopvarName+1""")
+                asmgen.translate(stmt.statements)
+                if(numElements<=255) {
+                    asmgen.out("""
+                        ldy  $indexVar
+                        iny
+                        cpy  #$numElements
+                        beq  $endLabel
+                        bne  $loopLabel""")
+                } else {
+                    // length is 256
+                    asmgen.out("""
+                        ldy  $indexVar
+                        iny
+                        bne  $loopLabel
+                        beq  $endLabel""")
+                }
+                if(numElements>=16) {
+                    // allocate index var on ZP if possible
+                    val result = zeropage.allocate(indexVar, DataType.UBYTE, null, stmt.position, asmgen.errors)
+                    result.fold(
+                        success = { (address,_,_)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
                        failure = { asmgen.out("$indexVar    .byte  0") }
                    )
                } else {
@@ -345,17 +518,19 @@ $loopLabel          sty  $indexVar
            }
            else -> throw AssemblyError("can't iterate over $iterableDt")
        }
-        asmgen.loopEndLabels.pop()
+        asmgen.loopEndLabels.removeLast()
    }

    private fun translateForOverConstRange(stmt: PtForLoop, iterableDt: DataType, range: IntProgression) {
        if (range.isEmpty() || range.step==0)
            throw AssemblyError("empty range or step 0")
        if(iterableDt==DataType.ARRAY_B || iterableDt==DataType.ARRAY_UB) {
+            if(range.last==range.first) return translateForSimpleByteRangeAsc(stmt, range)
            if(range.step==1 && range.last>range.first) return translateForSimpleByteRangeAsc(stmt, range)
-            if(range.step==-1 && range.last<range.first) return translateForSimpleByteRangeDesc(stmt, range)
+            if(range.step==-1 && range.last<range.first) return translateForSimpleByteRangeDesc(stmt, range, iterableDt==DataType.ARRAY_UB)
        }
        else if(iterableDt==DataType.ARRAY_W || iterableDt==DataType.ARRAY_UW) {
+            if(range.last==range.first) return translateForSimpleWordRangeAsc(stmt, range)
            if(range.step==1 && range.last>range.first) return translateForSimpleWordRangeAsc(stmt, range)
            if(range.step==-1 && range.last<range.first) return translateForSimpleWordRangeDesc(stmt, range)
        }
@@ -363,7 +538,7 @@ $loopLabel          sty  $indexVar
        // not one of the easy cases, generate more complex code...
        val loopLabel = asmgen.makeLabel("for_loop")
        val endLabel = asmgen.makeLabel("for_end")
-        asmgen.loopEndLabels.push(endLabel)
+        asmgen.loopEndLabels.add(endLabel)
        when(iterableDt) {
            DataType.ARRAY_B, DataType.ARRAY_UB -> {
                // loop over byte range via loopvar, step >= 2 or <= -2
@@ -375,7 +550,7 @@ $loopLabel""")
                asmgen.translate(stmt.statements)
                when (range.step) {
                    0, 1, -1 -> {
-                        throw AssemblyError("step 0, 1 and -1 should have been handled specifically  $stmt")
+                        throw AssemblyError("step 0, 1 and -1 should have been handled specifically  $range ${stmt.position}")
                    }
                    2 -> {
                        if(range.last==255 || range.last==254) {
@@ -469,13 +644,13 @@ $loopLabel""")
            }
            else -> throw AssemblyError("range expression can only be byte or word")
        }
-        asmgen.loopEndLabels.pop()
+        asmgen.loopEndLabels.removeLast()
    }

    private fun translateForSimpleByteRangeAsc(stmt: PtForLoop, range: IntProgression) {
        val loopLabel = asmgen.makeLabel("for_loop")
        val endLabel = asmgen.makeLabel("for_end")
-        asmgen.loopEndLabels.push(endLabel)
+        asmgen.loopEndLabels.add(endLabel)
        val varname = asmgen.asmVariableName(stmt.variable)
        asmgen.out("""
                lda  #${range.first}
@@ -495,50 +670,50 @@ $endLabel""")
                bne  $loopLabel
 $endLabel""")
        }
-        asmgen.loopEndLabels.pop()
+        asmgen.loopEndLabels.removeLast()
    }

-    private fun translateForSimpleByteRangeDesc(stmt: PtForLoop, range: IntProgression) {
+    private fun translateForSimpleByteRangeDesc(stmt: PtForLoop, range: IntProgression, unsigned: Boolean) {
        val loopLabel = asmgen.makeLabel("for_loop")
-        val endLabel = asmgen.makeLabel("for_end")
-        asmgen.loopEndLabels.push(endLabel)
        val varname = asmgen.asmVariableName(stmt.variable)
        asmgen.out("""
-                    lda  #${range.first}
-                    sta  $varname
+            lda  #${range.first}
+            sta  $varname
 $loopLabel""")
        asmgen.translate(stmt.statements)
        when (range.last) {
            0 -> {
-                asmgen.out("""
-                    lda  $varname
-                    beq  $endLabel
-                    dec  $varname""")
-                asmgen.jmp(loopLabel)
-                asmgen.out(endLabel)
+                if(!unsigned || range.first<=127) {
+                    asmgen.out("""
+                        dec  $varname
+                        bpl  $loopLabel""")
+                } else {
+                    asmgen.out("""
+                        dec  $varname
+                        lda  $varname
+                        cmp  #255
+                        bne  $loopLabel""")
+                }
            }
            1 -> {
                asmgen.out("""
                    dec  $varname
-                    bne  $loopLabel
-$endLabel""")
+                    bne  $loopLabel""")
            }
            else -> {
                asmgen.out("""
                    dec  $varname
                    lda  $varname
                    cmp  #${range.last-1}
-                    bne  $loopLabel
-$endLabel""")
+                    bne  $loopLabel""")
            }
        }
-        asmgen.loopEndLabels.pop()
    }

    private fun translateForSimpleWordRangeAsc(stmt: PtForLoop, range: IntProgression) {
        val loopLabel = asmgen.makeLabel("for_loop")
        val endLabel = asmgen.makeLabel("for_end")
-        asmgen.loopEndLabels.push(endLabel)
+        asmgen.loopEndLabels.add(endLabel)
        val varname = asmgen.asmVariableName(stmt.variable)
        asmgen.out("""
            lda  #<${range.first}
@@ -559,13 +734,13 @@ $loopLabel""")
            inc  $varname+1""")
        asmgen.jmp(loopLabel)
        asmgen.out(endLabel)
-        asmgen.loopEndLabels.pop()
+        asmgen.loopEndLabels.removeLast()
    }

    private fun translateForSimpleWordRangeDesc(stmt: PtForLoop, range: IntProgression) {
        val loopLabel = asmgen.makeLabel("for_loop")
        val endLabel = asmgen.makeLabel("for_end")
-        asmgen.loopEndLabels.push(endLabel)
+        asmgen.loopEndLabels.add(endLabel)
        val varname = asmgen.asmVariableName(stmt.variable)
        asmgen.out("""
            lda  #<${range.first}
@@ -574,26 +749,34 @@ $loopLabel""")
            sty  $varname+1
 $loopLabel""")
        asmgen.translate(stmt.statements)
+        if(range.last==0) {
+            asmgen.out("""
+                lda  $varname
+                bne  ++
+                lda  $varname+1
+                beq  $endLabel""")
+        } else {
+            asmgen.out("""
+                lda  $varname
+                cmp  #<${range.last}
+                bne  +
+                lda  $varname+1
+                cmp  #>${range.last}
+                beq  $endLabel""")
+        }
        asmgen.out("""
-            lda  $varname
-            cmp  #<${range.last}
-            bne  +
-            lda  $varname+1
-            cmp  #>${range.last}
-            beq  $endLabel
 +           lda  $varname
            bne  +
            dec  $varname+1
 +           dec  $varname""")
        asmgen.jmp(loopLabel)
        asmgen.out(endLabel)
-        asmgen.loopEndLabels.pop()
+        asmgen.loopEndLabels.removeLast()
    }

-    private fun assignLoopvar(stmt: PtForLoop, range: PtRange) =
+    private fun assignLoopvarWord(stmt: PtForLoop, range: PtRange) =
        asmgen.assignExpressionToVariable(
            range.from,
            asmgen.asmVariableName(stmt.variable),
-            stmt.variable.type,
-            stmt.definingISub())
+            stmt.variable.type)
 }
@@ -11,45 +11,13 @@ import prog8.codegen.cpu6502.assignment.TargetStorageKind
 internal class FunctionCallAsmGen(private val program: PtProgram, private val asmgen: AsmGen6502Internal) {

    internal fun translateFunctionCallStatement(stmt: PtFunctionCall) {
-        saveXbeforeCall(stmt)
        translateFunctionCall(stmt)
-        restoreXafterCall(stmt)
        // just ignore any result values from the function call.
    }

-    internal fun saveXbeforeCall(stmt: PtFunctionCall) {
-        val symbol = asmgen.symbolTable.lookup(stmt.name)
-        val sub = symbol!!.astNode as IPtSubroutine
-        if(sub.shouldSaveX()) {
-            if(sub is PtAsmSub) {
-                val regSaveOnStack = sub.address == 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.definingISub()!!)
-            } else
-                asmgen.saveRegisterLocal(CpuRegister.X, stmt.definingISub()!!)
-        }
-    }
-
-    internal fun restoreXafterCall(stmt: PtFunctionCall) {
-        val symbol = asmgen.symbolTable.lookup(stmt.name)
-        val sub = symbol!!.astNode as IPtSubroutine
-        if(sub.shouldSaveX()) {
-            if(sub is PtAsmSub) {
-                val regSaveOnStack = sub.address == 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)
-            } else
-                asmgen.restoreRegisterLocal(CpuRegister.X)
-        }
-    }
-
    internal fun optimizeIntArgsViaRegisters(sub: PtSub) =
-        (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)
+        (sub.parameters.size==1 && sub.parameters[0].type in IntegerDatatypesWithBoolean)
+                || (sub.parameters.size==2 && sub.parameters[0].type in ByteDatatypesWithBoolean && sub.parameters[1].type in ByteDatatypesWithBoolean)

    internal fun translateFunctionCall(call: PtFunctionCall) {
        // Output only the code to set up the parameters and perform the actual call
@@ -58,13 +26,13 @@ internal class FunctionCallAsmGen(private val program: PtProgram, private val as
        //       (you can use subroutine.shouldSaveX() and saveX()/restoreX() routines as a help for this)

        val symbol = asmgen.symbolTable.lookup(call.name)
-        val sub = symbol!!.astNode as IPtSubroutine
+        val sub = symbol?.astNode as IPtSubroutine
        val subAsmName = asmgen.asmSymbolName(call.name)

        if(sub is PtAsmSub) {
            argumentsViaRegisters(sub, call)
-            if (sub.inline && asmgen.options.optimize) {
-                // inline the subroutine.
+            if (sub.inline) {
+                // inline the subroutine. (regardless of optimization settings!)
                // we do this by copying the subroutine's statements at the call site.
                // NOTE: *if* there is a return statement, it will be the only one, and the very last statement of the subroutine
                // (this condition has been enforced by an ast check earlier)
@@ -78,7 +46,7 @@ internal class FunctionCallAsmGen(private val program: PtProgram, private val as
        else if(sub is PtSub) {
            if(optimizeIntArgsViaRegisters(sub)) {
                if(sub.parameters.size==1) {
-                    val register = if (sub.parameters[0].type in ByteDatatypes) RegisterOrPair.A else RegisterOrPair.AY
+                    val register = if (sub.parameters[0].type in ByteDatatypesWithBoolean) RegisterOrPair.A else RegisterOrPair.AY
                    argumentViaRegister(sub, IndexedValue(0, sub.parameters[0]), call.args[0], register)
                } else {
                    // 2 byte params, second in Y, first in A
@@ -101,37 +69,60 @@ internal class FunctionCallAsmGen(private val program: PtProgram, private val as
        // remember: dealing with the X register and/or dealing with return values is the responsibility of the caller
    }

-    private fun argumentsViaRegisters(sub: PtAsmSub, call: PtFunctionCall) {
-        if(sub.parameters.size==1) {
-            argumentViaRegister(sub, IndexedValue(0, sub.parameters.single().second), call.args[0])
-        } else {
-            if(asmsub6502ArgsHaveRegisterClobberRisk(call.args, sub.parameters)) {
-                registerArgsViaCpuStackEvaluation(call, sub)
-            } else {
-                asmsub6502ArgsEvalOrder(sub).forEach {
-                    val param = sub.parameters[it]
-                    val arg = call.args[it]
-                    argumentViaRegister(sub, IndexedValue(it, param.second), arg)
-                }
+
+    private fun usesOtherRegistersWhileEvaluating(arg: PtExpression): Boolean {
+        return when(arg) {
+            is PtBuiltinFunctionCall -> {
+                if (arg.name == "lsb" || arg.name == "msb")
+                    return usesOtherRegistersWhileEvaluating(arg.args[0])
+                if (arg.name == "mkword")
+                    return usesOtherRegistersWhileEvaluating(arg.args[0]) || usesOtherRegistersWhileEvaluating(arg.args[1])
+                return !arg.isSimple()
            }
+            is PtAddressOf -> false
+            is PtIdentifier -> false
+            is PtIrRegister -> false
+            is PtMemoryByte -> arg.address !is PtNumber && arg.address !is PtIdentifier
+            is PtNumber -> false
+            is PtBool -> false
+            else -> true
        }
    }

-    private fun registerArgsViaCpuStackEvaluation(call: PtFunctionCall, callee: PtAsmSub) {
-        // 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.
+    private fun argumentsViaRegisters(sub: PtAsmSub, call: PtFunctionCall) {
+        val registersUsed = mutableListOf<RegisterOrStatusflag>()

-        if(callee.parameters.isEmpty())
-            return
+        fun usedA() = registersUsed.any {it.registerOrPair==RegisterOrPair.A || it.registerOrPair==RegisterOrPair.AX || it.registerOrPair==RegisterOrPair.AY}
+        fun usedX() = registersUsed.any {it.registerOrPair==RegisterOrPair.X || it.registerOrPair==RegisterOrPair.AX || it.registerOrPair==RegisterOrPair.XY}
+        fun usedY() = registersUsed.any {it.registerOrPair==RegisterOrPair.Y || it.registerOrPair==RegisterOrPair.AY || it.registerOrPair==RegisterOrPair.XY}

-        // use the cpu hardware stack as intermediate storage for the arguments.
-        val argOrder = asmsub6502ArgsEvalOrder(callee)
-        argOrder.reversed().forEach {
-            asmgen.pushCpuStack(callee.parameters[it].second.type, call.args[it])
-        }
-        argOrder.forEach {
-            val param = callee.parameters[it]
-            asmgen.popCpuStack(callee, param.second, param.first)
+        if(sub.parameters.size==1) {
+            argumentViaRegister(sub, IndexedValue(0, sub.parameters.single().second), call.args[0])
+        } else {
+            val optimalEvalOrder = asmsub6502ArgsEvalOrder(sub)
+            optimalEvalOrder.forEach {
+                val param = sub.parameters[it]
+                val arg = call.args[it]
+                registersUsed += if(usesOtherRegistersWhileEvaluating(arg)) {
+                    if(!registersUsed.any{it.statusflag!=null || it.registerOrPair in CpuRegisters})
+                        argumentViaRegister(sub, IndexedValue(it, param.second), arg)
+                    else if(registersUsed.any {it.statusflag!=null}) {
+                        throw AssemblyError("call argument evaluation problem: can't save cpu statusregister parameter ${call.position}")
+                    }
+                    else {
+                        if(usedX()) asmgen.saveRegisterStack(CpuRegister.X, usedA())
+                        if(usedY()) asmgen.saveRegisterStack(CpuRegister.Y, usedA())
+                        if(usedA()) asmgen.saveRegisterStack(CpuRegister.A, usedA())
+                        val used = argumentViaRegister(sub, IndexedValue(it, param.second), arg)
+                        if(usedA()) asmgen.restoreRegisterStack(CpuRegister.A, false)
+                        if(usedY()) asmgen.restoreRegisterStack(CpuRegister.Y, true)
+                        if(usedX()) asmgen.restoreRegisterStack(CpuRegister.X, true)
+                        used
+                    }
+                } else {
+                    argumentViaRegister(sub, IndexedValue(it, param.second), arg)
+                }
+            }
        }
    }

@@ -141,10 +132,10 @@ internal class FunctionCallAsmGen(private val program: PtProgram, private val as
            throw AssemblyError("argument type incompatible")

        val varName = asmgen.asmVariableName(sub.scopedName + "." + parameter.name)
-        asmgen.assignExpressionToVariable(value, varName, parameter.type, sub)
+        asmgen.assignExpressionToVariable(value, varName, parameter.type)
    }

-    private fun argumentViaRegister(sub: IPtSubroutine, parameter: IndexedValue<PtSubroutineParameter>, value: PtExpression, registerOverride: RegisterOrPair? = null) {
+    private fun argumentViaRegister(sub: IPtSubroutine, parameter: IndexedValue<PtSubroutineParameter>, value: PtExpression, registerOverride: RegisterOrPair? = null): RegisterOrStatusflag {
        // pass argument via a register parameter
        if(!isArgumentTypeCompatible(value.type, parameter.value.type))
            throw AssemblyError("argument type incompatible")
@@ -162,17 +153,21 @@ internal class FunctionCallAsmGen(private val program: PtProgram, private val as
        }
        if (statusflag!=null) {
            if(requiredDt!=value.type)
-                throw AssemblyError("for statusflag, byte value is required")
+                throw AssemblyError("for statusflag, byte or bool value is required")
            if (statusflag == Statusflag.Pc) {
-                // this param needs to be set last, right before the jsr
+                // this boolean param needs to be set last, right before the jsr
                // for now, this is already enforced on the subroutine definition by the Ast Checker
                when(value) {
                    is PtNumber -> {
                        val carrySet = value.number.toInt() != 0
                        asmgen.out(if(carrySet) "  sec" else "  clc")
                    }
+                    is PtBool -> {
+                        asmgen.out(if(value.value) "  sec" else "  clc")
+                    }
                    is PtIdentifier -> {
                        val sourceName = asmgen.asmVariableName(value)
+                        // note: cannot use X register here to store A because it might be used for other arguments
                        asmgen.out("""
                            pha
                            clc
@@ -183,37 +178,34 @@ internal class FunctionCallAsmGen(private val program: PtProgram, private val as
                    }
                    else -> {
                        asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
-                        asmgen.out("""
-                            beq  +
-                            sec
-                            bcs  ++
-+                           clc
-+""")
+                        asmgen.out("  ror  a")
                    }
                }
            } else throw AssemblyError("can only use Carry as status flag parameter")
+            return RegisterOrStatusflag(null, statusflag)
        }
        else {
            // via register or register pair
            register!!
            if(requiredDt largerThan value.type) {
                // we need to sign extend the source, do this via temporary word variable
-                asmgen.assignExpressionToVariable(value, "P8ZP_SCRATCH_W1", DataType.UBYTE, sub)
+                asmgen.assignExpressionToVariable(value, "P8ZP_SCRATCH_W1", DataType.UBYTE)
                asmgen.signExtendVariableLsb("P8ZP_SCRATCH_W1", value.type)
-                asmgen.assignVariableToRegister("P8ZP_SCRATCH_W1", register)
+                asmgen.assignVariableToRegister("P8ZP_SCRATCH_W1", register, null, Position.DUMMY)
            } else {
+                val scope = value.definingISub()
                val target: AsmAssignTarget =
                    if(parameter.value.type in ByteDatatypes && (register==RegisterOrPair.AX || register == RegisterOrPair.AY || register==RegisterOrPair.XY || register in Cx16VirtualRegisters))
-                        AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, parameter.value.type, sub, register = register)
+                        AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, parameter.value.type, scope, value.position, register = register)
                    else {
                        val signed = parameter.value.type == DataType.BYTE || parameter.value.type == DataType.WORD
-                        AsmAssignTarget.fromRegisters(register, signed, sub, asmgen)
+                        AsmAssignTarget.fromRegisters(register, signed, value.position, scope, asmgen)
                    }
                val src = if(value.type in PassByReferenceDatatypes) {
                    if(value is PtIdentifier) {
                        val addr = PtAddressOf(Position.DUMMY)
                        addr.add(value)
-                        addr.parent = sub as PtNode
+                        addr.parent = scope as PtNode
                        AsmAssignSource.fromAstSource(addr, program, asmgen).adjustSignedUnsigned(target)
                    } else {
                        AsmAssignSource.fromAstSource(value, program, asmgen).adjustSignedUnsigned(target)
@@ -221,14 +213,17 @@ internal class FunctionCallAsmGen(private val program: PtProgram, private val as
                } else {
                    AsmAssignSource.fromAstSource(value, program, asmgen).adjustSignedUnsigned(target)
                }
-                asmgen.translateNormalAssignment(AsmAssignment(src, target, program.memsizer, Position.DUMMY))
+                asmgen.translateNormalAssignment(AsmAssignment(src, target, program.memsizer, target.position), scope)
            }
+            return RegisterOrStatusflag(register, null)
        }
    }

    private fun isArgumentTypeCompatible(argType: DataType, paramType: DataType): Boolean {
        if(argType isAssignableTo paramType)
            return true
+        if(argType==DataType.BOOL && paramType==DataType.BOOL)
+            return true
        if(argType in ByteDatatypes && paramType in ByteDatatypes)
            return true
        if(argType in WordDatatypes && paramType in WordDatatypes)
@@ -244,3 +239,5 @@ internal class FunctionCallAsmGen(private val program: PtProgram, private val as
        return false
    }
 }
+
+
@@ -1,126 +0,0 @@
-package prog8.codegen.cpu6502
-
-import prog8.code.ast.PtIdentifier
-import prog8.code.ast.PtNumber
-import prog8.code.ast.PtPostIncrDecr
-import prog8.code.ast.PtProgram
-import prog8.code.core.*
-
-
-internal class PostIncrDecrAsmGen(private val program: PtProgram, private val asmgen: AsmGen6502Internal) {
-    internal fun translate(stmt: PtPostIncrDecr) {
-        val incr = stmt.operator=="++"
-        val targetIdent = stmt.target.identifier
-        val targetMemory = stmt.target.memory
-        val targetArrayIdx = stmt.target.array
-        val scope = stmt.definingISub()
-        when {
-            targetIdent!=null -> {
-                val what = asmgen.asmVariableName(targetIdent)
-                when (stmt.target.type) {
-                    in ByteDatatypes -> asmgen.out(if (incr) "  inc  $what" else "  dec  $what")
-                    in WordDatatypes -> {
-                        if(incr)
-                            asmgen.out(" inc  $what |  bne  + |  inc  $what+1 |+")
-                        else
-                            asmgen.out("""
-        lda  $what
-        bne  +
-        dec  $what+1
-+       dec  $what 
-""")
-                    }
-                    DataType.FLOAT -> {
-                        asmgen.out("  lda  #<$what |  ldy  #>$what")
-                        asmgen.out(if(incr) "  jsr  floats.inc_var_f" else "  jsr  floats.dec_var_f")
-                    }
-                    else -> throw AssemblyError("need numeric type")
-                }
-            }
-            targetMemory!=null -> {
-                when (val addressExpr = targetMemory.address) {
-                    is PtNumber -> {
-                        val what = addressExpr.number.toHex()
-                        asmgen.out(if(incr) "  inc  $what" else "  dec  $what")
-                    }
-                    is PtIdentifier -> {
-                        val what = asmgen.asmVariableName(addressExpr)
-                        asmgen.out("  lda  $what |  sta  (+) +1 |  lda  $what+1 |  sta  (+) +2")
-                        if(incr)
-                            asmgen.out("+\tinc  ${'$'}ffff\t; modified")
-                        else
-                            asmgen.out("+\tdec  ${'$'}ffff\t; modified")
-                    }
-                    else -> {
-                        asmgen.assignExpressionToRegister(addressExpr, RegisterOrPair.AY)
-                        asmgen.out("  sta  (+) + 1 |  sty  (+) + 2")
-                        if(incr)
-                            asmgen.out("+\tinc  ${'$'}ffff\t; modified")
-                        else
-                            asmgen.out("+\tdec  ${'$'}ffff\t; modified")
-                    }
-                }
-            }
-            targetArrayIdx!=null -> {
-                val asmArrayvarname = asmgen.asmVariableName(targetArrayIdx.variable)
-                val elementDt = targetArrayIdx.type
-                val constIndex = targetArrayIdx.index.asConstInteger()
-                if(constIndex!=null) {
-                    val indexValue = constIndex * program.memsizer.memorySize(elementDt)
-                    when(elementDt) {
-                        in ByteDatatypes -> asmgen.out(if (incr) "  inc  $asmArrayvarname+$indexValue" else "  dec  $asmArrayvarname+$indexValue")
-                        in WordDatatypes -> {
-                            if(incr)
-                                asmgen.out(" inc  $asmArrayvarname+$indexValue |  bne  + |  inc  $asmArrayvarname+$indexValue+1 |+")
-                            else
-                                asmgen.out("""
-    lda  $asmArrayvarname+$indexValue
-    bne  +
-    dec  $asmArrayvarname+$indexValue+1
-+       dec  $asmArrayvarname+$indexValue 
-""")
-                        }
-                        DataType.FLOAT -> {
-                            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")
-                    }
-                }
-                else
-                {
-                    asmgen.loadScaledArrayIndexIntoRegister(targetArrayIdx, elementDt, CpuRegister.A)
-                    asmgen.saveRegisterLocal(CpuRegister.X, scope!!)
-                    asmgen.out("  tax")
-                    when(elementDt) {
-                        in ByteDatatypes -> {
-                            asmgen.out(if(incr) "  inc  $asmArrayvarname,x" else "  dec  $asmArrayvarname,x")
-                        }
-                        in WordDatatypes -> {
-                            if(incr)
-                                asmgen.out(" inc  $asmArrayvarname,x |  bne  + |  inc  $asmArrayvarname+1,x |+")
-                            else
-                                asmgen.out("""
-    lda  $asmArrayvarname,x
-    bne  +
-    dec  $asmArrayvarname+1,x
-+       dec  $asmArrayvarname,x 
-""")
-                        }
-                        DataType.FLOAT -> {
-                            asmgen.out("""
-                    ldy  #>$asmArrayvarname
-                    clc
-                    adc  #<$asmArrayvarname
-                    bcc  +
-                    iny
-+                       jsr  floats.inc_var_f""")
-                        }
-                        else -> throw AssemblyError("weird array elt dt")
-                    }
-                    asmgen.restoreRegisterLocal(CpuRegister.X)
-                }
-            }
-        }
-    }
-}
@@ -33,8 +33,9 @@ internal class ProgramAndVarsGen(
    internal fun generate() {
        header()
        val allBlocks = program.allBlocks()
-        if(allBlocks.first().name != "main")
-            throw AssemblyError("first block should be 'main'")
+
+        if(allBlocks.first().name != "p8b_main" && allBlocks.first().name != "main")
+            throw AssemblyError("first block should be 'main' or 'p8b_main'")

        if(errors.noErrors())  {
            program.allBlocks().forEach { block2asm(it) }
@@ -48,6 +49,7 @@ internal class ProgramAndVarsGen(
            }

            memorySlabs()
+            tempVars()
            footer()
        }
    }
@@ -74,8 +76,6 @@ internal class ProgramAndVarsGen(
        asmgen.out("P8ZP_SCRATCH_W1 = ${zp.SCRATCH_W1}    ; word")
        asmgen.out("P8ZP_SCRATCH_W2 = ${zp.SCRATCH_W2}    ; word")
        asmgen.out(".weak")   // hack to allow user to override the following two with command line redefinition (however, just use '-esa' command line option instead!)
-        asmgen.out("P8ESTACK_LO = ${compTarget.machine.ESTACK_LO.toHex()}")
-        asmgen.out("P8ESTACK_HI = ${compTarget.machine.ESTACK_HI.toHex()}")
        asmgen.out(".endweak")

        if(options.symbolDefs.isNotEmpty()) {
@@ -104,15 +104,15 @@ internal class ProgramAndVarsGen(
                        asmgen.out("+\t.word  0")
                        asmgen.out("prog8_entrypoint\t; assembly code starts here")
                        if(!options.noSysInit)
-                            asmgen.out("  jsr  ${compTarget.name}.init_system")
-                        asmgen.out("  jsr  ${compTarget.name}.init_system_phase2")
+                            asmgen.out("  jsr  sys.init_system")
+                        asmgen.out("  jsr  sys.init_system_phase2")
                    }
                    CbmPrgLauncherType.NONE -> {
                        asmgen.out("; ---- program without basic sys call ----")
                        asmgen.out("* = ${options.loadAddress.toHex()}")
                        if(!options.noSysInit)
-                            asmgen.out("  jsr  ${compTarget.name}.init_system")
-                        asmgen.out("  jsr  ${compTarget.name}.init_system_phase2")
+                            asmgen.out("  jsr  sys.init_system")
+                        asmgen.out("  jsr  sys.init_system_phase2")
                    }
                }
            }
@@ -120,8 +120,8 @@ internal class ProgramAndVarsGen(
                asmgen.out("; ---- atari xex program ----")
                asmgen.out("* = ${options.loadAddress.toHex()}")
                if(!options.noSysInit)
-                    asmgen.out("  jsr  ${compTarget.name}.init_system")
-                asmgen.out("  jsr  ${compTarget.name}.init_system_phase2")
+                    asmgen.out("  jsr  sys.init_system")
+                asmgen.out("  jsr  sys.init_system_phase2")
            }
        }

@@ -134,30 +134,22 @@ internal class ProgramAndVarsGen(
                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")
-                asmgen.out("  jmp  ${compTarget.name}.cleanup_at_exit")
+                asmgen.out("  jsr  p8b_main.p8s_start")
+                asmgen.out("  jmp  sys.cleanup_at_exit")
            }
            "c64" -> {
-                asmgen.out("  jsr  main.start |  lda  #31 |  sta  $01")
-                if(!options.noSysInit)
-                    asmgen.out("  jmp  ${compTarget.name}.cleanup_at_exit")
-                else
-                    asmgen.out("  rts")
+                asmgen.out("  jsr  p8b_main.p8s_start |  lda  #31 |  sta  $01")
+                asmgen.out("  jmp  sys.cleanup_at_exit")
            }
            "c128" -> {
-                asmgen.out("  jsr  main.start")
-                // TODO c128: how to bank basic+kernal back in?
-                if(!options.noSysInit)
-                    asmgen.out("  jmp  ${compTarget.name}.cleanup_at_exit")
-                else
-                    asmgen.out("  rts")
+                asmgen.out("  jsr  p8b_main.p8s_start |  lda  #0 |  sta ${"$"}ff00")
+                asmgen.out("  jmp  sys.cleanup_at_exit")
            }
-            else -> asmgen.jmp("main.start")
+            else -> asmgen.jmp("p8b_main.p8s_start")
        }
    }

@@ -174,47 +166,120 @@ internal class ProgramAndVarsGen(
        }
    }

+    private fun tempVars() {
+        asmgen.out("; expression temp vars\n  .section BSS")
+        for((dt, count) in asmgen.tempVarsCounters) {
+            if(count>0) {
+                for(num in 1..count) {
+                    val name = asmgen.buildTempVarName(dt, num)
+                    when (dt) {
+                        DataType.BOOL  -> asmgen.out("$name    .byte  ?")
+                        DataType.BYTE  -> asmgen.out("$name    .char  ?")
+                        DataType.UBYTE -> asmgen.out("$name    .byte  ?")
+                        DataType.WORD  -> asmgen.out("$name    .sint  ?")
+                        DataType.UWORD -> asmgen.out("$name    .word  ?")
+                        DataType.FLOAT -> asmgen.out("$name    .fill  ${options.compTarget.machine.FLOAT_MEM_SIZE}")
+                        else -> throw AssemblyError("weird dt for extravar $dt")
+                    }
+                }
+            }
+        }
+        asmgen.out("  .send BSS")
+    }
+
    private fun footer() {
+        var relocateBssVars = false
+        var relocateBssSlabs = false
+        var relocatedBssStart = 0u
+        var relocatedBssEnd = 0u
+
+        if(options.varsGolden) {
+            if(options.compTarget.machine.BSSGOLDENRAM_START == 0u ||
+                options.compTarget.machine.BSSGOLDENRAM_END == 0u ||
+                options.compTarget.machine.BSSGOLDENRAM_END <= options.compTarget.machine.BSSGOLDENRAM_START) {
+                throw AssemblyError("current compilation target hasn't got the golden ram area properly defined or it is simply not available")
+            }
+            relocateBssVars = true
+            relocatedBssStart = options.compTarget.machine.BSSGOLDENRAM_START
+            relocatedBssEnd = options.compTarget.machine.BSSGOLDENRAM_END
+        }
+        else if(options.varsHighBank!=null) {
+            if(options.compTarget.machine.BSSHIGHRAM_START == 0u ||
+                options.compTarget.machine.BSSHIGHRAM_END == 0u ||
+                options.compTarget.machine.BSSHIGHRAM_END <= options.compTarget.machine.BSSHIGHRAM_START) {
+                throw AssemblyError("current compilation target hasn't got the high ram area properly defined or it is simply not available")
+            }
+            if(options.slabsHighBank!=null && options.varsHighBank!=options.slabsHighBank)
+                throw AssemblyError("slabs and vars high bank must be the same")
+            relocateBssVars = true
+            relocatedBssStart = options.compTarget.machine.BSSHIGHRAM_START
+            relocatedBssEnd = options.compTarget.machine.BSSHIGHRAM_END
+        }
+
+        if(options.slabsGolden) {
+            if(options.compTarget.machine.BSSGOLDENRAM_START == 0u ||
+                options.compTarget.machine.BSSGOLDENRAM_END == 0u ||
+                options.compTarget.machine.BSSGOLDENRAM_END <= options.compTarget.machine.BSSGOLDENRAM_START) {
+                throw AssemblyError("current compilation target hasn't got the golden ram area properly defined or it is simply not available")
+            }
+            relocateBssSlabs = true
+            relocatedBssStart = options.compTarget.machine.BSSGOLDENRAM_START
+            relocatedBssEnd = options.compTarget.machine.BSSGOLDENRAM_END
+        }
+        else if(options.slabsHighBank!=null) {
+            if(options.compTarget.machine.BSSHIGHRAM_START == 0u ||
+                options.compTarget.machine.BSSHIGHRAM_END == 0u ||
+                options.compTarget.machine.BSSHIGHRAM_END <= options.compTarget.machine.BSSHIGHRAM_START) {
+                throw AssemblyError("current compilation target hasn't got the high ram area properly defined or it is simply not available")
+            }
+            if(options.varsHighBank!=null && options.varsHighBank!=options.slabsHighBank)
+                throw AssemblyError("slabs and vars high bank must be the same")
+            relocateBssSlabs = true
+            relocatedBssStart = options.compTarget.machine.BSSHIGHRAM_START
+            relocatedBssEnd = options.compTarget.machine.BSSHIGHRAM_END
+        }
+
        asmgen.out("; bss sections")
-        if(options.varsHigh) {
-            if(options.compTarget.machine.BSSHIGHRAM_START == 0u || options.compTarget.machine.BSSHIGHRAM_END==0u) {
-                throw AssemblyError("current compilation target hasn't got the high ram area properly defined")
-            }
-            // BSS vars in high ram area, memory() slabs just concatenated at the end of the program.
-            if(symboltable.allMemorySlabs.isNotEmpty()) {
+        asmgen.out("PROG8_VARSHIGH_RAMBANK = ${options.varsHighBank ?: 1}")
+        if(relocateBssVars) {
+            if(!relocateBssSlabs)
                asmgen.out("  .dsection slabs_BSS")
-            }
            asmgen.out("prog8_program_end\t; end of program label for progend()")
-            asmgen.out("  * = ${options.compTarget.machine.BSSHIGHRAM_START.toHex()}")
+            asmgen.out("  * = ${relocatedBssStart.toHex()}")
            asmgen.out("prog8_bss_section_start")
            asmgen.out("  .dsection BSS")
-            asmgen.out("  .cerror * >= ${options.compTarget.machine.BSSHIGHRAM_END.toHex()}, \"too many variables for BSS section\"")
+            if(relocateBssSlabs)
+                asmgen.out("  .dsection slabs_BSS")
+            asmgen.out("  .cerror * > ${relocatedBssEnd.toHex()}, \"too many variables/data for BSS section\"")
            asmgen.out("prog8_bss_section_size = * - prog8_bss_section_start")
        } else {
-            // BSS vars followed by memory() slabs, concatenated at the end of the program.
            asmgen.out("prog8_bss_section_start")
            asmgen.out("  .dsection BSS")
            asmgen.out("prog8_bss_section_size = * - prog8_bss_section_start")
-            if(symboltable.allMemorySlabs.isNotEmpty()) {
+            if(!relocateBssSlabs)
                asmgen.out("  .dsection slabs_BSS")
-            }
            asmgen.out("prog8_program_end\t; end of program label for progend()")
+            if(relocateBssSlabs) {
+                asmgen.out("  * = ${relocatedBssStart.toHex()}")
+                asmgen.out("  .dsection slabs_BSS")
+                asmgen.out("  .cerror * > ${relocatedBssEnd.toHex()}, \"too many data for slabs_BSS section\"")
+            }
        }
    }

    private fun block2asm(block: PtBlock) {
        asmgen.out("")
        asmgen.out("; ---- block: '${block.name}' ----")
-        if(block.address!=null)
-            asmgen.out("* = ${block.address!!.toHex()}")
+        if(block.options.address!=null)
+            asmgen.out("* = ${block.options.address!!.toHex()}")
        else {
-            if(block.alignment==PtBlock.BlockAlignment.WORD)
+            if(block.options.alignment==PtBlock.BlockAlignment.WORD)
                asmgen.out("\t.align 2")
-            else if(block.alignment==PtBlock.BlockAlignment.PAGE)
+            else if(block.options.alignment==PtBlock.BlockAlignment.PAGE)
                asmgen.out("\t.align $100")
        }

-        asmgen.out("${block.name}\t" + (if(block.forceOutput) ".block" else ".proc"))
+        asmgen.out("${block.name}\t" + (if(block.options.forceOutput) ".block" else ".proc"))
        asmgen.outputSourceLine(block)

        createBlockVariables(block)
@@ -237,7 +302,7 @@ internal class ProgramAndVarsGen(
            asmgen.out("  rts\n  .bend")
        }

-        asmgen.out(if(block.forceOutput) "\n\t.bend" else "\n\t.pend")
+        asmgen.out(if(block.options.forceOutput) "\n\t.bend" else "\n\t.pend")
    }

    private fun getVars(scope: StNode): Map<String, StNode> =
@@ -270,16 +335,14 @@ internal class ProgramAndVarsGen(

    internal fun translateAsmSubroutine(sub: PtAsmSub) {
        if(sub.inline) {
-            if(options.optimize) {
-                return
-            }
+            return      // subroutine gets inlined at call site.
        }

        asmgen.out("")

        val asmStartScope: String
        val asmEndScope: String
-        if(sub.definingBlock()!!.forceOutput) {
+        if(sub.definingBlock()!!.options.forceOutput) {
            asmStartScope = ".block"
            asmEndScope = ".bend"
        } else {
@@ -302,7 +365,7 @@ internal class ProgramAndVarsGen(

        val asmStartScope: String
        val asmEndScope: String
-        if(sub.definingBlock()!!.forceOutput) {
+        if(sub.definingBlock()!!.options.forceOutput) {
            asmStartScope = ".block"
            asmEndScope = ".bend"
        } else {
@@ -312,7 +375,9 @@ internal class ProgramAndVarsGen(

        asmgen.out("${sub.name}\t$asmStartScope")

-        val scope = symboltable.lookupOrElse(sub.scopedName) { throw AssemblyError("lookup") }
+        val scope = symboltable.lookupOrElse(sub.scopedName) {
+            throw AssemblyError("lookup ${sub.scopedName}")
+        }
        require(scope.type==StNodeType.SUBROUTINE)
        val varsInSubroutine = getVars(scope)

@@ -332,23 +397,23 @@ internal class ProgramAndVarsGen(
        asmsubs2asm(sub.children)

        // the main.start subroutine is the program's entrypoint and should perform some initialization logic
-        if(sub.name=="start" && sub.definingBlock()!!.name=="main")
+        if((sub.name=="start" || sub.name=="p8s_start") && (sub.definingBlock()!!.name=="main" || sub.definingBlock()!!.name=="p8b_main"))
            entrypointInitialization()

        if(functioncallAsmGen.optimizeIntArgsViaRegisters(sub)) {
            asmgen.out("; simple int arg(s) passed via register(s)")
            if(sub.parameters.size==1) {
                val dt = sub.parameters[0].type
-                val target = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, dt, sub, variableAsmName = sub.parameters[0].name)
-                if(dt in ByteDatatypes)
+                val target = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, dt, sub, sub.parameters[0].position, variableAsmName = sub.parameters[0].name)
+                if(dt in ByteDatatypesWithBoolean)
                    asmgen.assignRegister(RegisterOrPair.A, target)
                else
                    asmgen.assignRegister(RegisterOrPair.AY, target)
            } else {
                require(sub.parameters.size==2)
                // 2 simple byte args, first in A, second in Y
-                val target1 = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, sub.parameters[0].type, sub, variableAsmName = sub.parameters[0].name)
-                val target2 = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, sub.parameters[1].type, sub, variableAsmName = sub.parameters[1].name)
+                val target1 = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, sub.parameters[0].type, sub, sub.parameters[0].position, variableAsmName = sub.parameters[0].name)
+                val target2 = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, sub.parameters[1].type, sub, sub.parameters[1].position, variableAsmName = sub.parameters[1].name)
                asmgen.assignRegister(RegisterOrPair.A, target1)
                asmgen.assignRegister(RegisterOrPair.Y, target2)
            }
@@ -358,26 +423,23 @@ internal class ProgramAndVarsGen(
        sub.children.forEach { asmgen.translate(it) }

        asmgen.out("; variables")
+        asmgen.out("    .section BSS")
        val asmGenInfo = asmgen.subroutineExtra(sub)
        for((dt, name, addr) in asmGenInfo.extraVars) {
            if(addr!=null)
                asmgen.out("$name = $addr")
            else when(dt) {
-                DataType.UBYTE -> asmgen.out("$name    .byte  0")
-                DataType.UWORD -> asmgen.out("$name    .word  0")
-                else -> throw AssemblyError("weird dt")
+                DataType.UBYTE -> asmgen.out("$name    .byte  ?")
+                DataType.UWORD -> asmgen.out("$name    .word  ?")
+                DataType.FLOAT -> asmgen.out("$name    .fill  ${options.compTarget.machine.FLOAT_MEM_SIZE}")
+                else -> throw AssemblyError("weird dt for extravar $dt")
            }
        }
-        if(asmGenInfo.usedRegsaveA)      // will probably never occur
-            asmgen.out("prog8_regsaveA     .byte  0")
-        if(asmGenInfo.usedRegsaveX)
-            asmgen.out("prog8_regsaveX     .byte  0")
-        if(asmGenInfo.usedRegsaveY)
-            asmgen.out("prog8_regsaveY     .byte  0")
        if(asmGenInfo.usedFloatEvalResultVar1)
-            asmgen.out("$subroutineFloatEvalResultVar1    .byte  0,0,0,0,0")
+            asmgen.out("$subroutineFloatEvalResultVar1    .fill  ${options.compTarget.machine.FLOAT_MEM_SIZE}")
        if(asmGenInfo.usedFloatEvalResultVar2)
-            asmgen.out("$subroutineFloatEvalResultVar2    .byte  0,0,0,0,0")
+            asmgen.out("$subroutineFloatEvalResultVar2    .fill  ${options.compTarget.machine.FLOAT_MEM_SIZE}")
+        asmgen.out("  .send BSS")

        // normal statically allocated variables
        val variables = varsInSubroutine
@@ -432,12 +494,12 @@ internal class ProgramAndVarsGen(
                asmgen.out("""
                    lda  #<${name}_init_value
                    ldy  #>${name}_init_value
-                    sta  cx16.r0L
-                    sty  cx16.r0H
+                    sta  cx16.r0
+                    sty  cx16.r0+1
                    lda  #<${name}
                    ldy  #>${name}
-                    sta  cx16.r1L
-                    sty  cx16.r1H
+                    sta  cx16.r1
+                    sty  cx16.r1+1
                    lda  #<$size
                    ldy  #>$size
                    jsr  sys.memcopy""")
@@ -456,7 +518,6 @@ internal class ProgramAndVarsGen(
        }

        asmgen.out("""+        
-                    ldx  #127       ; init estack ptr (half page)
                    clv
                    clc""")
    }
@@ -478,8 +539,8 @@ internal class ProgramAndVarsGen(
        val vars = allocator.zeropageVars.filter { it.value.dt==DataType.STR }
        for (variable in vars) {
            val scopedName = variable.key
-            val svar = symboltable.flat.getValue(scopedName) as StStaticVariable
-            if(svar.onetimeInitializationStringValue!=null)
+            val svar = symboltable.lookup(scopedName) as? StStaticVariable
+            if(svar?.onetimeInitializationStringValue!=null)
                result.add(ZpStringWithInitial(scopedName, variable.value, svar.onetimeInitializationStringValue!!))
        }
        return result
@@ -490,8 +551,8 @@ internal class ProgramAndVarsGen(
        val vars = allocator.zeropageVars.filter { it.value.dt in ArrayDatatypes }
        for (variable in vars) {
            val scopedName = variable.key
-            val svar = symboltable.flat.getValue(scopedName) as StStaticVariable
-            if(svar.onetimeInitializationArrayValue!=null)
+            val svar = symboltable.lookup(scopedName) as? StStaticVariable
+            if(svar?.onetimeInitializationArrayValue!=null)
                result.add(ZpArrayWithInitial(scopedName, variable.value, svar.onetimeInitializationArrayValue!!))
        }
        return result
@@ -502,7 +563,15 @@ internal class ProgramAndVarsGen(
        for ((scopedName, zpvar) in zpVariables) {
            if (scopedName.startsWith("cx16.r"))
                continue        // The 16 virtual registers of the cx16 are not actual variables in zp, they're memory mapped
-            asmgen.out("${scopedName.substringAfterLast('.')} \t= ${zpvar.address} \t; zp ${zpvar.dt}")
+            val variable = symboltable.flat.getValue(scopedName) as StStaticVariable
+            if(variable.dt in SplitWordArrayTypes) {
+                val lsbAddr = zpvar.address
+                val msbAddr = zpvar.address + (zpvar.size/2).toUInt()
+                asmgen.out("${scopedName.substringAfterLast('.')}_lsb \t= $lsbAddr \t; zp ${zpvar.dt} (lsbs)")
+                asmgen.out("${scopedName.substringAfterLast('.')}_msb \t= $msbAddr \t; zp ${zpvar.dt} (msbs)")
+            } else {
+                asmgen.out("${scopedName.substringAfterLast('.')} \t= ${zpvar.address} \t; zp ${zpvar.dt}")
+            }
        }
    }

@@ -536,11 +605,16 @@ internal class ProgramAndVarsGen(

    private fun uninitializedVariable2asm(variable: StStaticVariable) {
        when (variable.dt) {
-            DataType.UBYTE -> asmgen.out("${variable.name}\t.byte  ?")
+            DataType.BOOL, DataType.UBYTE -> asmgen.out("${variable.name}\t.byte  ?")
            DataType.BYTE -> asmgen.out("${variable.name}\t.char  ?")
            DataType.UWORD -> asmgen.out("${variable.name}\t.word  ?")
            DataType.WORD -> asmgen.out("${variable.name}\t.sint  ?")
            DataType.FLOAT -> asmgen.out("${variable.name}\t.fill  ${compTarget.machine.FLOAT_MEM_SIZE}")
+            in SplitWordArrayTypes -> {
+                val numbytesPerHalf = compTarget.memorySize(variable.dt, variable.length!!) / 2
+                asmgen.out("${variable.name}_lsb\t.fill  $numbytesPerHalf")
+                asmgen.out("${variable.name}_msb\t.fill  $numbytesPerHalf")
+            }
            in ArrayDatatypes -> {
                val numbytes = compTarget.memorySize(variable.dt, variable.length!!)
                asmgen.out("${variable.name}\t.fill  $numbytes")
@@ -561,7 +635,7 @@ internal class ProgramAndVarsGen(
            } else 0

        when (variable.dt) {
-            DataType.UBYTE -> asmgen.out("${variable.name}\t.byte  ${initialValue.toHex()}")
+            DataType.BOOL, DataType.UBYTE -> asmgen.out("${variable.name}\t.byte  ${initialValue.toHex()}")
            DataType.BYTE -> asmgen.out("${variable.name}\t.char  $initialValue")
            DataType.UWORD -> asmgen.out("${variable.name}\t.word  ${initialValue.toHex()}")
            DataType.WORD -> asmgen.out("${variable.name}\t.sint  $initialValue")
@@ -585,7 +659,7 @@ internal class ProgramAndVarsGen(

    private fun arrayVariable2asm(varname: String, dt: DataType, value: StArray?, orNumberOfZeros: Int?) {
        when(dt) {
-            DataType.ARRAY_UB -> {
+            DataType.ARRAY_UB, DataType.ARRAY_BOOL -> {
                val data = makeArrayFillDataUnsigned(dt, value, orNumberOfZeros)
                if (data.size <= 16)
                    asmgen.out("$varname\t.byte  ${data.joinToString()}")
@@ -625,6 +699,18 @@ internal class ProgramAndVarsGen(
                        asmgen.out("  .sint  " + chunk.joinToString())
                }
            }
+            DataType.ARRAY_UW_SPLIT -> {
+                val data = makeArrayFillDataUnsigned(dt, value, orNumberOfZeros)
+                asmgen.out("_array_$varname := ${data.joinToString()}")
+                asmgen.out("${varname}_lsb\t.byte <_array_$varname")
+                asmgen.out("${varname}_msb\t.byte >_array_$varname")
+            }
+            DataType.ARRAY_W_SPLIT -> {
+                val data = makeArrayFillDataSigned(dt, value, orNumberOfZeros)
+                asmgen.out("_array_$varname := ${data.joinToString()}")
+                asmgen.out("${varname}_lsb\t.byte <_array_$varname")
+                asmgen.out("${varname}_msb\t.byte >_array_$varname")
+            }
            DataType.ARRAY_F -> {
                val array = value ?: zeroFilledArray(orNumberOfZeros!!)
                val floatFills = array.map {
@@ -641,7 +727,7 @@ internal class ProgramAndVarsGen(
    private fun zeroFilledArray(numElts: Int): StArray {
        val values = mutableListOf<StArrayElement>()
        repeat(numElts) {
-            values.add(StArrayElement(0.0, null))
+            values.add(StArrayElement(0.0, null, null))
        }
        return values
    }
@@ -678,13 +764,23 @@ internal class ProgramAndVarsGen(
    private fun makeArrayFillDataUnsigned(dt: DataType, value: StArray?, orNumberOfZeros: Int?): List<String> {
        val array = value ?: zeroFilledArray(orNumberOfZeros!!)
        return when (dt) {
+            DataType.ARRAY_BOOL ->
+                // byte array can never contain pointer-to types, so treat values as all integers
+                array.map {
+                    if(it.boolean!=null)
+                        if(it.boolean==true) "1" else "0"
+                    else {
+                        val number = it.number!!
+                        if(number==0.0) "0" else "1"
+                    }
+                }
            DataType.ARRAY_UB ->
                // byte array can never contain pointer-to types, so treat values as all integers
                array.map {
                    val number = it.number!!.toInt()
                    "$"+number.toString(16).padStart(2, '0')
                }
-            DataType.ARRAY_UW -> array.map {
+            DataType.ARRAY_UW, DataType.ARRAY_UW_SPLIT -> array.map {
                if(it.number!=null) {
                    "$" + it.number!!.toInt().toString(16).padStart(4, '0')
                }
@@ -716,11 +812,11 @@ internal class ProgramAndVarsGen(
                    else
                        "-$$hexnum"
                }
-            DataType.ARRAY_UW -> array.map {
+            DataType.ARRAY_UW, DataType.ARRAY_UW_SPLIT -> array.map {
                val number = it.number!!.toInt()
                "$" + number.toString(16).padStart(4, '0')
            }
-            DataType.ARRAY_W -> array.map {
+            DataType.ARRAY_W, DataType.ARRAY_W_SPLIT -> array.map {
                val number = it.number!!.toInt()
                val hexnum = number.absoluteValue.toString(16).padStart(4, '0')
                if(number>=0)
@@ -48,9 +48,9 @@ internal class VariableAllocator(private val symboltable: SymbolTable,
        val numberOfAllocatableVariables = allVariables.size
        val varsRequiringZp = allVariables.filter { it.zpwish == ZeropageWish.REQUIRE_ZEROPAGE }
        val varsPreferringZp = allVariables.filter { it.zpwish == ZeropageWish.PREFER_ZEROPAGE }
+        val varsNotZp = allVariables.filter { it.zpwish == ZeropageWish.NOT_IN_ZEROPAGE }
        val varsDontCare = allVariables.filter { it.zpwish == ZeropageWish.DONTCARE }
-        val numberOfExplicitNonZpVariables = allVariables.count { it.zpwish == ZeropageWish.NOT_IN_ZEROPAGE }
-        require(varsDontCare.size + varsRequiringZp.size + varsPreferringZp.size + numberOfExplicitNonZpVariables == numberOfAllocatableVariables)
+        require(varsDontCare.size + varsRequiringZp.size + varsPreferringZp.size + varsNotZp.size == numberOfAllocatableVariables)

        var numVariablesAllocatedInZP = 0
        var numberOfNonIntegerVariables = 0
@@ -86,12 +86,12 @@ internal class VariableAllocator(private val symboltable: SymbolTable,
                //  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.
+            // try to allocate the "don't care" interger variables into the zeropage until it is full.
            // TODO some form of intelligent priorization? most often used variables first? loopcounter vars first? ...?
            if(errors.noErrors()) {
                val sortedList = varsDontCare.sortedByDescending { it.scopedName }
                for (variable in sortedList) {
-                    if(variable.dt in IntegerDatatypes) {
+                    if(variable.dt in IntegerDatatypesWithBoolean) {
                        if(zeropage.free.isEmpty()) {
                            break
                        } else {
@@ -110,9 +110,7 @@ internal class VariableAllocator(private val symboltable: SymbolTable,
            }
        }

-//        println("  number of allocated vars: $numberOfAllocatableVariables")
-//        println("  put into zeropage: $numVariablesAllocatedInZP,  non-zp allocatable: ${numberOfNonIntegerVariables+numberOfExplicitNonZpVariables}")
-//        println("  zeropage free space: ${zeropage.free.size} bytes")
+        // note: no zeropage allocation is done at all for the @nozp variables. This means they will always end up outside the zeropage.
    }

    private fun collectAllVariables(st: SymbolTable): Collection<StStaticVariable> {
@@ -0,0 +1,207 @@
+package prog8.codegen.cpu6502.assignment
+
+import prog8.code.ast.PtBinaryExpression
+import prog8.code.ast.PtExpression
+import prog8.code.core.*
+import prog8.code.target.C64Target
+import prog8.code.target.Cx16Target
+import prog8.codegen.cpu6502.AsmGen6502Internal
+
+//
+// This contains codegen for stack-based evaluation of binary expressions.
+// It uses the CPU stack so depth is limited.
+// It is called "as a last resort" if the optimized codegen path is unable
+// to come up with a special case of the expression.
+//
+internal class AnyExprAsmGen(
+    private val asmgen: AsmGen6502Internal
+) {
+    fun assignAnyExpressionUsingStack(expr: PtBinaryExpression, assign: AsmAssignment): Boolean {
+        when(expr.type) {
+            in ByteDatatypesWithBoolean -> {
+                if(expr.left.type in ByteDatatypesWithBoolean && expr.right.type in ByteDatatypesWithBoolean)
+                    return assignByteBinExpr(expr, assign)
+                if (expr.left.type in WordDatatypes && expr.right.type in WordDatatypes) {
+                    require(expr.operator in ComparisonOperators)
+                    throw AssemblyError("words operands comparison -> byte, should have been handled elsewhere")
+                }
+                if (expr.left.type==DataType.FLOAT && expr.right.type==DataType.FLOAT) {
+                    require(expr.operator in ComparisonOperators)
+                    return assignFloatBinExpr(expr, assign)
+                }
+                throw AssemblyError("weird expr operand types: ${expr.left.type} and ${expr.right.type}")
+            }
+            in WordDatatypes -> {
+                require(expr.left.type in WordDatatypes && expr.right.type in WordDatatypes) {
+                    "both operands must be words"
+                }
+                throw AssemblyError("expression should have been handled otherwise: word ${expr.operator} at ${expr.position}")
+            }
+            DataType.FLOAT -> {
+                require(expr.left.type==DataType.FLOAT && expr.right.type==DataType.FLOAT) {
+                    "both operands must be floats"
+                }
+                return assignFloatBinExpr(expr, assign)
+            }
+            else -> throw AssemblyError("weird expression type in assignment")
+        }
+    }
+
+    private fun assignByteBinExpr(expr: PtBinaryExpression, assign: AsmAssignment): Boolean {
+        when(expr.operator) {
+            "+" -> {
+                asmgen.assignExpressionToRegister(expr.left, RegisterOrPair.A, false)
+                asmgen.out("  pha")
+                asmgen.assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_B1", DataType.UBYTE)
+                asmgen.out("  pla |  clc |  adc  P8ZP_SCRATCH_B1")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "-" -> {
+                asmgen.assignExpressionToRegister(expr.left, RegisterOrPair.A, false)
+                asmgen.out("  pha")
+                asmgen.assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_B1", DataType.UBYTE)
+                asmgen.out("  pla |  sec |  sbc  P8ZP_SCRATCH_B1")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "*" -> TODO("byte * at ${expr.position}")
+            "/" -> TODO("byte / at ${expr.position}")
+            "<<" -> TODO("byte << at ${expr.position}")
+            ">>" -> TODO("byte >> at ${expr.position}")
+            "%" -> TODO("byte % at ${expr.position}")
+            "and" -> TODO("logical and (with optional shortcircuit) ${expr.position}")
+            "or" -> TODO("logical or (with optional shortcircuit) ${expr.position}")
+            "&" -> {
+                asmgen.assignExpressionToRegister(expr.left, RegisterOrPair.A, false)
+                asmgen.out("  pha")
+                asmgen.assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_B1", DataType.UBYTE)
+                asmgen.out("  pla |  and  P8ZP_SCRATCH_B1")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "|" -> {
+                asmgen.assignExpressionToRegister(expr.left, RegisterOrPair.A, false)
+                asmgen.out("  pha")
+                asmgen.assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_B1", DataType.UBYTE)
+                asmgen.out("  pla |  ora  P8ZP_SCRATCH_B1")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "^", "xor" -> {
+                asmgen.assignExpressionToRegister(expr.left, RegisterOrPair.A, false)
+                asmgen.out("  pha")
+                asmgen.assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_B1", DataType.UBYTE)
+                asmgen.out("  pla |  eor  P8ZP_SCRATCH_B1")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "==" -> TODO("byte == at ${expr.position}")
+            "!=" -> TODO("byte != at ${expr.position}")
+            "<" -> TODO("byte < at ${expr.position}")
+            "<=" -> TODO("byte <= at ${expr.position}")
+            ">" -> TODO("byte > at ${expr.position}")
+            ">=" -> TODO("byte >= at ${expr.position}")
+            else -> return false
+        }
+    }
+
+    private fun assignFloatBinExpr(expr: PtBinaryExpression, assign: AsmAssignment): Boolean {
+        when(expr.operator) {
+            "+" -> {
+                assignFloatOperandsToFACandARG(expr.left, expr.right)
+                asmgen.out("  jsr  floats.FADDT")
+                asmgen.assignRegister(RegisterOrPair.FAC1, assign.target)
+                return true
+            }
+            "-" -> {
+                assignFloatOperandsToFACandARG(expr.right, expr.left)
+                asmgen.out("  jsr  floats.FSUBT")
+                asmgen.assignRegister(RegisterOrPair.FAC1, assign.target)
+                return true
+            }
+            "*" -> {
+                assignFloatOperandsToFACandARG(expr.left, expr.right)
+                asmgen.out("  jsr  floats.FMULTT")
+                asmgen.assignRegister(RegisterOrPair.FAC1, assign.target)
+                return true
+            }
+            "/" -> {
+                assignFloatOperandsToFACandARG(expr.right, expr.left)
+                asmgen.out("  jsr  floats.FDIVT")
+                asmgen.assignRegister(RegisterOrPair.FAC1, assign.target)
+                return true
+            }
+            "==" -> {
+                setupFloatComparisonFAC1vsVarAY(expr)
+                asmgen.out("  jsr  floats.var_fac1_equal_f")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "!=" -> {
+                setupFloatComparisonFAC1vsVarAY(expr)
+                asmgen.out("  jsr  floats.var_fac1_notequal_f")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "<" -> {
+                setupFloatComparisonFAC1vsVarAY(expr)
+                asmgen.out("  jsr  floats.var_fac1_less_f")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            ">" -> {
+                setupFloatComparisonFAC1vsVarAY(expr)
+                asmgen.out("  jsr  floats.var_fac1_greater_f")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            "<=" -> {
+                setupFloatComparisonFAC1vsVarAY(expr)
+                asmgen.out("  jsr  floats.var_fac1_lesseq_f")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            ">=" -> {
+                setupFloatComparisonFAC1vsVarAY(expr)
+                asmgen.out("  jsr  floats.var_fac1_greatereq_f")
+                asmgen.assignRegister(RegisterOrPair.A, assign.target)
+                return true
+            }
+            else -> TODO("float expression operator ${expr.operator}")
+        }
+    }
+
+    private fun assignFloatOperandsToFACandARG(left: PtExpression, right: PtExpression) {
+        when(asmgen.options.compTarget.name) {
+            C64Target.NAME -> {
+                // c64 has a quirk: always make sure FAC2 is loaded last (done using CONUPK)  otherwise the result will be corrupt on C64
+                // this requires some more forced copying around of float values in certain cases
+                if (right.isSimple()) {
+                    asmgen.assignExpressionToRegister(left, RegisterOrPair.FAC1, true)
+                    asmgen.assignExpressionToRegister(right, RegisterOrPair.FAC2, true)
+                } else {
+                    asmgen.assignExpressionToRegister(right, RegisterOrPair.FAC1, true)
+                    asmgen.pushFAC1()
+                    asmgen.assignExpressionToRegister(left, RegisterOrPair.FAC1, true)
+                    asmgen.popFAC2()
+                }
+            }
+            Cx16Target.NAME -> {
+                asmgen.assignExpressionToRegister(left, RegisterOrPair.FAC1, true)
+                if (!right.isSimple()) asmgen.pushFAC1()
+                asmgen.assignExpressionToRegister(right, RegisterOrPair.FAC2, true)
+                if (!right.isSimple()) asmgen.popFAC1()
+            }
+            else -> TODO("don't know how to evaluate float expression for selected compilation target")
+        }
+    }
+
+    private fun setupFloatComparisonFAC1vsVarAY(expr: PtBinaryExpression) {
+        asmgen.assignExpressionToRegister(expr.left, RegisterOrPair.FAC1, true)
+        if(!expr.right.isSimple()) asmgen.pushFAC1()
+        asmgen.assignExpressionToVariable(expr.right, "floats.floats_temp_var", DataType.FLOAT)
+        if(!expr.right.isSimple()) asmgen.popFAC1()
+        asmgen.out("  lda  #<floats.floats_temp_var |  ldy  #>floats.floats_temp_var")
+    }
+}
@@ -10,17 +10,16 @@ internal enum class TargetStorageKind {
    VARIABLE,
    ARRAY,
    MEMORY,
-    REGISTER,
-    STACK
+    REGISTER
 }

 internal enum class SourceStorageKind {
+    LITERALBOOLEAN,
    LITERALNUMBER,
    VARIABLE,
    ARRAY,
    MEMORY,
    REGISTER,
-    STACK,              // value is already present on stack
    EXPRESSION,         // expression in ast-form, still to be evaluated
 }

@@ -28,6 +27,7 @@ internal class AsmAssignTarget(val kind: TargetStorageKind,
                               private val asmgen: AsmGen6502Internal,
                               val datatype: DataType,
                               val scope: IPtSubroutine?,
+                               val position: Position,
                               private val variableAsmName: String? = null,
                               val array: PtArrayIndexer? = null,
                               val memory: PtMemoryByte? = null,
@@ -43,11 +43,9 @@ internal class AsmAssignTarget(val kind: TargetStorageKind,
            asmgen.asmVariableName(array.variable)
    }

-    lateinit var origAssign: AsmAssignmentBase
-
    init {
-        if(register!=null && datatype !in NumericDatatypes)
-            throw AssemblyError("register must be integer or float type")
+        if(register!=null && datatype !in NumericDatatypesWithBoolean)
+            throw AssemblyError("must be numeric type")
    }

    companion object {
@@ -63,28 +61,28 @@ internal class AsmAssignTarget(val kind: TargetStorageKind,
                                if(reg.statusflag!=null)
                                    throw AssemblyError("can't assign value to processor statusflag directly")
                                else
-                                    return AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, type, definingSub, register=reg.registerOrPair, origAstTarget = this)
+                                    return AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, type, definingSub, target.position, register=reg.registerOrPair, origAstTarget = this)
                            }
                        }
-                        return AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, type, definingSub, variableAsmName = asmgen.asmVariableName(identifier!!), origAstTarget =  this)
+                        return AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, type, definingSub, target.position, variableAsmName = asmgen.asmVariableName(identifier!!), origAstTarget =  this)
                    }
-                    array != null -> return AsmAssignTarget(TargetStorageKind.ARRAY, asmgen, type, definingSub, array = array, origAstTarget =  this)
-                    memory != null -> return AsmAssignTarget(TargetStorageKind.MEMORY, asmgen, type, definingSub, memory =  memory, origAstTarget =  this)
+                    array != null -> return AsmAssignTarget(TargetStorageKind.ARRAY, asmgen, type, definingSub, target.position, array = array, origAstTarget =  this)
+                    memory != null -> return AsmAssignTarget(TargetStorageKind.MEMORY, asmgen, type, definingSub, target.position, memory =  memory, origAstTarget =  this)
                    else -> throw AssemblyError("weird target")
                }
            }
        }

-        fun fromRegisters(registers: RegisterOrPair, signed: Boolean, scope: IPtSubroutine?, asmgen: AsmGen6502Internal): AsmAssignTarget =
+        fun fromRegisters(registers: RegisterOrPair, signed: Boolean, pos: Position, scope: IPtSubroutine?, asmgen: AsmGen6502Internal): AsmAssignTarget =
                when(registers) {
                    RegisterOrPair.A,
                    RegisterOrPair.X,
-                    RegisterOrPair.Y -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, if(signed) DataType.BYTE else DataType.UBYTE, scope, register = registers)
+                    RegisterOrPair.Y -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, if(signed) DataType.BYTE else DataType.UBYTE, scope, pos, register = registers)
                    RegisterOrPair.AX,
                    RegisterOrPair.AY,
-                    RegisterOrPair.XY -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, if(signed) DataType.WORD else DataType.UWORD, scope, register = registers)
+                    RegisterOrPair.XY -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, if(signed) DataType.WORD else DataType.UWORD, scope, pos, register = registers)
                    RegisterOrPair.FAC1,
-                    RegisterOrPair.FAC2 -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, DataType.FLOAT, scope, register = registers)
+                    RegisterOrPair.FAC2 -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, DataType.FLOAT, scope, pos, register = registers)
                    RegisterOrPair.R0,
                    RegisterOrPair.R1,
                    RegisterOrPair.R2,
@@ -100,9 +98,31 @@ internal class AsmAssignTarget(val kind: TargetStorageKind,
                    RegisterOrPair.R12,
                    RegisterOrPair.R13,
                    RegisterOrPair.R14,
-                    RegisterOrPair.R15 -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, if(signed) DataType.WORD else DataType.UWORD, scope, register = registers)
+                    RegisterOrPair.R15 -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, if(signed) DataType.WORD else DataType.UWORD, scope, pos, register = registers)
                }
    }
+
+    fun isSameAs(left: PtExpression): Boolean =
+        when(kind) {
+            TargetStorageKind.VARIABLE -> {
+                val scopedName: String = if('.' in asmVarname)
+                    asmVarname
+                else {
+                    val scopeName = (scope as? PtNamedNode)?.scopedName
+                    if (scopeName == null) asmVarname else "$scopeName.$asmVarname"
+                }
+                left is PtIdentifier && left.name==scopedName
+            }
+            TargetStorageKind.ARRAY -> {
+                left is PtArrayIndexer && left isSameAs array!! && left.splitWords==array.splitWords
+            }
+            TargetStorageKind.MEMORY -> {
+                left isSameAs memory!!
+            }
+            TargetStorageKind.REGISTER -> {
+                false
+            }
+        }
 }

 internal class AsmAssignSource(val kind: SourceStorageKind,
@@ -114,6 +134,7 @@ internal class AsmAssignSource(val kind: SourceStorageKind,
                               val memory: PtMemoryByte? = null,
                               val register: RegisterOrPair? = null,
                               val number: PtNumber? = null,
+                               val boolean: PtBool? = null,
                               val expression: PtExpression? = null
 )
 {
@@ -128,6 +149,9 @@ internal class AsmAssignSource(val kind: SourceStorageKind,
            val cv = value as? PtNumber
            if(cv!=null)
                return AsmAssignSource(SourceStorageKind.LITERALNUMBER, program, asmgen, cv.type, number = cv)
+            val bv = value as? PtBool
+            if(bv!=null)
+                return AsmAssignSource(SourceStorageKind.LITERALBOOLEAN, program, asmgen, DataType.BOOL, boolean = bv)

            return when(value) {
                // checked above:   is PtNumber -> throw AssemblyError("should have been constant value")
@@ -157,8 +181,8 @@ internal class AsmAssignSource(val kind: SourceStorageKind,
                    AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, value.type, expression = value)
                }
                is PtFunctionCall -> {
-                    val symbol = asmgen.symbolTable.lookup(value.name)
-                    val sub = symbol!!.astNode as IPtSubroutine
+                    val symbol = asmgen.symbolTable.lookup(value.name) ?: throw AssemblyError("lookup error ${value.name}")
+                    val sub = symbol.astNode as IPtSubroutine
                    val returnType = sub.returnsWhatWhere().firstOrNull { rr -> rr.first.registerOrPair != null || rr.first.statusflag!=null }?.second
                            ?: throw AssemblyError("can't translate zero return values in assignment")

@@ -175,7 +199,7 @@ internal class AsmAssignSource(val kind: SourceStorageKind,
        // allow some signed/unsigned relaxations

        fun withAdjustedDt(newType: DataType) =
-                AsmAssignSource(kind, program, asmgen, newType, variableAsmName, array, memory, register, number, expression)
+                AsmAssignSource(kind, program, asmgen, newType, variableAsmName, array, memory, register, number, boolean, expression)

        if(target.datatype!=datatype) {
            if(target.datatype in ByteDatatypes && datatype in ByteDatatypes) {
@@ -5,7 +5,7 @@ import prog8.code.core.*

 internal object DummyMemsizer : IMemSizer {
    override fun memorySize(dt: DataType) = when(dt) {
-        in ByteDatatypes -> 1
+        in ByteDatatypesWithBoolean -> 1
        DataType.FLOAT -> 5
        else -> 2
    }
@@ -18,6 +18,8 @@ internal object DummyMemsizer : IMemSizer {
 }

 internal object DummyStringEncoder : IStringEncoding {
+    override val defaultEncoding: Encoding = Encoding.ISO
+
    override fun encodeString(str: String, encoding: Encoding): List<UByte> {
        return emptyList()
    }
@@ -27,27 +29,43 @@ internal object DummyStringEncoder : IStringEncoding {
    }
 }

-internal class ErrorReporterForTests(private val throwExceptionAtReportIfErrors: Boolean=true, private val keepMessagesAfterReporting: Boolean=false):
-    IErrorReporter {
+internal class ErrorReporterForTests(private val throwExceptionAtReportIfErrors: Boolean=true, private val keepMessagesAfterReporting: Boolean=false): IErrorReporter {

    val errors = mutableListOf<String>()
    val warnings = mutableListOf<String>()
+    val infos = mutableListOf<String>()

    override fun err(msg: String, position: Position) {
-        errors.add("${position.toClickableStr()} $msg")
+        val text = "${position.toClickableStr()} $msg"
+        if(text !in errors)
+            errors.add(text)
    }

    override fun warn(msg: String, position: Position) {
-        warnings.add("${position.toClickableStr()} $msg")
+        val text = "${position.toClickableStr()} $msg"
+        if(text !in warnings)
+            warnings.add(text)
+    }
+
+    override fun info(msg: String, position: Position) {
+        val text = "${position.toClickableStr()} $msg"
+        if(text !in infos)
+            infos.add(text)
+    }
+
+    override fun undefined(symbol: List<String>, position: Position) {
+        err("undefined symbol: ${symbol.joinToString(".")}", position)
    }

    override fun noErrors(): Boolean  = errors.isEmpty()
+    override fun noErrorForLine(position: Position) = !errors.any { ":${position.line}:" in it }

    override fun report() {
+        infos.forEach { println("UNITTEST COMPILATION REPORT: INFO: $it") }
        warnings.forEach { println("UNITTEST COMPILATION REPORT: WARNING: $it") }
        errors.forEach { println("UNITTEST COMPILATION REPORT: ERROR: $it") }
        if(throwExceptionAtReportIfErrors)
-            finalizeNumErrors(errors.size, warnings.size)
+            finalizeNumErrors(errors.size, warnings.size, infos.size)
        if(!keepMessagesAfterReporting) {
            clear()
        }
@@ -56,5 +74,6 @@ internal class ErrorReporterForTests(private val throwExceptionAtReportIfErrors:
    fun clear() {
        errors.clear()
        warnings.clear()
+        infos.clear()
    }
 }
@@ -1,6 +1,9 @@
 package prog8tests.codegencpu6502

+import io.kotest.assertions.throwables.shouldNotThrowAny
+import io.kotest.assertions.withClue
 import io.kotest.core.spec.style.FunSpec
+import io.kotest.matchers.ints.shouldBeGreaterThanOrEqual
 import io.kotest.matchers.shouldBe
 import prog8.code.SymbolTableMaker
 import prog8.code.ast.*
@@ -19,6 +22,7 @@ class TestCodegen: FunSpec({
            CbmPrgLauncherType.NONE,
            ZeropageType.DONTUSE,
            zpReserved = emptyList(),
+            zpAllowed = CompilationOptions.AllZeropageAllowed,
            floats = true,
            noSysInit = false,
            compTarget = target,
@@ -39,9 +43,9 @@ class TestCodegen: FunSpec({
 //        xx += cx16.r0
 //    }
 //}
-        val codegen = AsmGen6502()
+        val codegen = AsmGen6502(prefixSymbols = false)
        val program = PtProgram("test", DummyMemsizer, DummyStringEncoder)
-        val block = PtBlock("main", null, false, false, PtBlock.BlockAlignment.NONE, SourceCode.Generated("test"), Position.DUMMY)
+        val block = PtBlock("main",false, SourceCode.Generated("test"), PtBlock.Options(), Position.DUMMY)
        val sub = PtSub("start", emptyList(), null, Position.DUMMY)
        sub.add(PtVariable("pi", DataType.UBYTE, ZeropageWish.DONTCARE, PtNumber(DataType.UBYTE, 0.0, Position.DUMMY), null, Position.DUMMY))
        sub.add(PtVariable("particleX", DataType.ARRAY_UB, ZeropageWish.DONTCARE, null, 3u, Position.DUMMY))
@@ -49,7 +53,7 @@ class TestCodegen: FunSpec({
        sub.add(PtVariable("xx", DataType.WORD, ZeropageWish.DONTCARE, PtNumber(DataType.WORD, 1.0, Position.DUMMY), null, Position.DUMMY))

        val assign = PtAugmentedAssign("+=", Position.DUMMY)
-        val target = PtAssignTarget(Position.DUMMY).also {
+        val target = PtAssignTarget(false, Position.DUMMY).also {
            val targetIdx = PtArrayIndexer(DataType.UBYTE, Position.DUMMY).also { idx ->
                idx.add(PtIdentifier("main.start.particleX", DataType.ARRAY_UB, Position.DUMMY))
                idx.add(PtNumber(DataType.UBYTE, 2.0, Position.DUMMY))
@@ -64,7 +68,7 @@ class TestCodegen: FunSpec({
        sub.add(assign)

        val prefixAssign = PtAugmentedAssign("-", Position.DUMMY)
-        val prefixTarget = PtAssignTarget(Position.DUMMY).also {
+        val prefixTarget = PtAssignTarget(false, Position.DUMMY).also {
            it.add(PtIdentifier("main.start.xx", DataType.WORD, Position.DUMMY))
        }
        prefixAssign.add(prefixTarget)
@@ -72,7 +76,7 @@ class TestCodegen: FunSpec({
        sub.add(prefixAssign)

        val numberAssign = PtAugmentedAssign("-=", Position.DUMMY)
-        val numberAssignTarget = PtAssignTarget(Position.DUMMY).also {
+        val numberAssignTarget = PtAssignTarget(false, Position.DUMMY).also {
            it.add(PtIdentifier("main.start.xx", DataType.WORD, Position.DUMMY))
        }
        numberAssign.add(numberAssignTarget)
@@ -80,7 +84,7 @@ class TestCodegen: FunSpec({
        sub.add(numberAssign)

        val cxregAssign = PtAugmentedAssign("+=", Position.DUMMY)
-        val cxregAssignTarget = PtAssignTarget(Position.DUMMY).also {
+        val cxregAssignTarget = PtAssignTarget(false, Position.DUMMY).also {
            it.add(PtIdentifier("main.start.xx", DataType.WORD, Position.DUMMY))
        }
        cxregAssign.add(cxregAssignTarget)
@@ -91,7 +95,7 @@ class TestCodegen: FunSpec({
        program.add(block)

        // define the "cx16.r0" virtual register
-        val cx16block = PtBlock("cx16", null, false, false, PtBlock.BlockAlignment.NONE, SourceCode.Generated("test"), Position.DUMMY)
+        val cx16block = PtBlock("cx16", false, SourceCode.Generated("test"), PtBlock.Options(), Position.DUMMY)
        cx16block.add(PtMemMapped("r0", DataType.UWORD, 100u, null, Position.DUMMY))
        program.add(cx16block)

@@ -102,5 +106,24 @@ class TestCodegen: FunSpec({
        result.name shouldBe "test"
        Files.deleteIfExists(Path("${result.name}.asm"))
    }
+
+    test("64tass assembler available? - if this fails you need to install 64tass version 1.58 or newer in the path") {
+        val command = mutableListOf("64tass", "--version")
+        shouldNotThrowAny {
+            val proc = ProcessBuilder(command).start()
+            val output = String(proc.inputStream.readBytes())
+            val result = proc.waitFor()
+            result.shouldBe(0)
+            val (_, version) = output.split('V')
+            val (major, minor, _) = version.split('.')
+            val majorNum = major.toInt()
+            val minorNum = minor.toInt()
+            withClue("64tass version should be 1.58 or newer") {
+                majorNum shouldBeGreaterThanOrEqual 1
+                if (majorNum == 1)
+                    minorNum shouldBeGreaterThanOrEqual 58
+            }
+        }
+    }
 })

@@ -6,9 +6,8 @@ plugins {
 }

 java {
-    toolchain {
-        languageVersion = JavaLanguageVersion.of(javaVersion)
-    }
+    targetCompatibility = JavaLanguageVersion.of(javaVersion)
+    sourceCompatibility = JavaLanguageVersion.of(javaVersion)
 }

 compileKotlin {
@@ -29,17 +28,17 @@ dependencies {
    implementation project(':codeGenIntermediate')
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
    // implementation "org.jetbrains.kotlin:kotlin-reflect"
-    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.16"
+    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:2.0.0"

 }

 sourceSets {
    main {
        java {
-            srcDirs = ["${project.projectDir}/src"]
+            srcDir "${project.projectDir}/src"
        }
        resources {
-            srcDirs = ["${project.projectDir}/res"]
+            srcDir "${project.projectDir}/res"
        }
    }
 }
@@ -15,7 +15,8 @@ class ExperiCodeGen: ICodeGeneratorBackend {
        symbolTable: SymbolTable,
        options: CompilationOptions,
        errors: IErrorReporter
-    ): IAssemblyProgram? {
+    ): IAssemblyProgram {
+
        // you could write a code generator directly on the PtProgram AST,
        // but you can also use the Intermediate Representation to build a codegen on:
        val irCodeGen = IRCodeGen(program, symbolTable, options, errors)
@@ -25,6 +26,15 @@ class ExperiCodeGen: ICodeGeneratorBackend {
        IRFileWriter(irProgram, null).write()

        println("** experimental codegen stub: no assembly generated **")
-        return null
+        return EmptyProgram
    }
-}
+}
+
+private object EmptyProgram : IAssemblyProgram {
+    override val name = "<Empty Program>"
+    override fun assemble(options: CompilationOptions, errors: IErrorReporter): Boolean {
+        println("** nothing assembled **")
+        return true
+    }
+
+}
@@ -6,9 +6,8 @@ plugins {
 }

 java {
-    toolchain {
-        languageVersion = JavaLanguageVersion.of(javaVersion)
-    }
+    targetCompatibility = JavaLanguageVersion.of(javaVersion)
+    sourceCompatibility = JavaLanguageVersion.of(javaVersion)
 }

 compileKotlin {
@@ -28,18 +27,22 @@ dependencies {
    implementation project(':intermediate')
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
    // implementation "org.jetbrains.kotlin:kotlin-reflect"
-    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.16"
+    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:2.0.0"
+
+    testImplementation 'io.kotest:kotest-runner-junit5-jvm:5.9.1'
+    testImplementation 'org.junit.jupiter:junit-jupiter:5.9.2'
+    testImplementation 'io.kotest:kotest-framework-datatest:5.9.1'
+    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'

-    testImplementation 'io.kotest:kotest-runner-junit5-jvm:5.3.2'
 }

 sourceSets {
    main {
        java {
-            srcDirs = ["${project.projectDir}/src"]
+            srcDir "${project.projectDir}/src"
        }
        resources {
-            srcDirs = ["${project.projectDir}/res"]
+            srcDir "${project.projectDir}/res"
        }
    }
    test {
@@ -14,5 +14,7 @@
    <orderEntry type="module" module-name="intermediate" />
    <orderEntry type="library" name="io.kotest.assertions.core.jvm" level="project" />
    <orderEntry type="library" name="io.kotest.runner.junit5.jvm" level="project" />
+    <orderEntry type="library" name="io.kotest.framework.datatest" level="project" />
+    <orderEntry type="library" name="michael.bull.kotlin.result.jvm" level="project" />
  </component>
 </module>
@@ -1,12 +1,42 @@
 package prog8.codegen.intermediate

+import prog8.code.core.IErrorReporter
 import prog8.intermediate.*

-internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
-    fun optimize() {
-        irprog.blocks.asSequence().flatMap { it.children.filterIsInstance<IRSubroutine>() }.forEach { sub ->
+class IRPeepholeOptimizer(private val irprog: IRProgram) {
+    fun optimize(optimizationsEnabled: Boolean, errors: IErrorReporter) {
+        if(!optimizationsEnabled)
+            return optimizeOnlyJoinChunks()
+
+        peepholeOptimize()
+        val remover = IRUnusedCodeRemover(irprog, errors)
+        var totalRemovals = 0
+        do {
+            val numRemoved = remover.optimize()
+            totalRemovals += numRemoved
+        } while(numRemoved>0 && errors.noErrors())
+        errors.report()
+
+        if(totalRemovals>0) {
+            irprog.linkChunks()  // re-link again.
+        }
+    }
+
+    private fun optimizeOnlyJoinChunks() {
+        irprog.foreachSub { sub ->
+            joinChunks(sub)
            removeEmptyChunks(sub)
            joinChunks(sub)
+        }
+        irprog.linkChunks() // re-link
+    }
+
+    private fun peepholeOptimize() {
+        irprog.foreachSub { sub ->
+            joinChunks(sub)
+            removeEmptyChunks(sub)
+            joinChunks(sub)
+
            sub.chunks.withIndex().forEach { (index, chunk1) ->
                // we don't optimize Inline Asm chunks here.
                val chunk2 = if(index<sub.chunks.size-1) sub.chunks[index+1] else null
@@ -15,20 +45,36 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
                        val indexedInstructions = chunk1.instructions.withIndex()
                            .map { IndexedValue(it.index, it.value) }
                        val changed = removeNops(chunk1, indexedInstructions)
-                                || removeDoubleLoadsAndStores(chunk1, indexedInstructions)       // TODO not yet implemented
+                                || replaceConcatZeroMsbWithExt(chunk1, indexedInstructions)
+                                || removeDoubleLoadsAndStores(chunk1, indexedInstructions)
                                || removeUselessArithmetic(chunk1, indexedInstructions)
+                                || removeNeedlessCompares(chunk1, indexedInstructions)
                                || removeWeirdBranches(chunk1, chunk2, indexedInstructions)
                                || removeDoubleSecClc(chunk1, indexedInstructions)
                                || cleanupPushPop(chunk1, indexedInstructions)
-                        // TODO other optimizations:
-                        //  more complex optimizations such as unused registers
                    } while (changed)
                }
            }
            removeEmptyChunks(sub)
        }

-        irprog.linkChunks() // re-link
+        irprog.linkChunks()  // re-link
+    }
+
+    private fun replaceConcatZeroMsbWithExt(chunk: IRCodeChunk, indexedInstructions: List<IndexedValue<IRInstruction>>): Boolean {
+        var changed = false
+        indexedInstructions.reversed().forEach { (idx, ins) ->
+            if (ins.opcode == Opcode.CONCAT) {
+                // if the previous instruction loads a zero in the msb, this can be turned into EXT.B instead
+                val prev = indexedInstructions[idx-1].value
+                if(prev.opcode==Opcode.LOAD && prev.immediate==0 && prev.reg1==ins.reg2) {
+                    chunk.instructions[idx] = IRInstruction(Opcode.EXT, IRDataType.BYTE, reg1 = ins.reg1, reg2 = ins.reg3)
+                    chunk.instructions.removeAt(idx-1)
+                    changed = true
+                }
+            }
+        }
+        return changed
    }

    private fun removeEmptyChunks(sub: IRSubroutine) {
@@ -38,7 +84,7 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
        /*
        Empty Code chunk with label ->
            If next chunk has no label -> move label to next chunk, remove original
-            If next chunk has label -> label name should be the same, remove original. Otherwise FOR NOW leave it in place. (TODO: consolidate labels into 1)
+            If next chunk has label -> label name should be the same, remove original. Otherwise merge both labels into 1.
            If is last chunk -> keep chunk in place because of the label.
        Empty Code chunk without label ->
            should not have been generated! ERROR.
@@ -47,6 +93,7 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {

        val relabelChunks = mutableListOf<Pair<Int, String>>()
        val removeChunks = mutableListOf<Int>()
+        val replaceLabels = mutableMapOf<String, String>()

        sub.chunks.withIndex().forEach { (index, chunk) ->
            if(chunk is IRCodeChunk && chunk.instructions.isEmpty()) {
@@ -60,10 +107,18 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
                            relabelChunks += Pair(index + 1, chunk.label!!)
                            removeChunks += index
                        } else {
-                            if (chunk.label == nextchunk.label)
-                                removeChunks += index
-                            else {
-                                // TODO: consolidate labels on same chunk
+                            // merge both labels into 1 except if this is the label chunk at the start of the subroutine
+                            if(index>0) {
+                                if (chunk.label == nextchunk.label)
+                                    removeChunks += index
+                                else {
+                                    removeChunks += index
+                                    replaceLabels[chunk.label!!] = nextchunk.label!!
+                                    replaceLabels.entries.forEach { (key, value) ->
+                                        if (value == chunk.label)
+                                            replaceLabels[key] = nextchunk.label!!
+                                    }
+                                }
                            }
                        }
                    }
@@ -73,10 +128,32 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {

        relabelChunks.forEach { (index, label) ->
            val chunk = IRCodeChunk(label, null)
-            chunk.instructions += sub.chunks[index].instructions
+            val subChunk = sub.chunks[index]
+            chunk.instructions += subChunk.instructions
+            if(subChunk is IRCodeChunk)
+                chunk.appendSrcPositions(subChunk.sourceLinesPositions)
            sub.chunks[index] = chunk
        }
        removeChunks.reversed().forEach { index -> sub.chunks.removeAt(index) }
+
+        sub.chunks.forEach { chunk ->
+            chunk.instructions.withIndex().forEach { (idx, instr) ->
+                instr.labelSymbol?.let {
+                    if(instr.opcode in OpcodesThatBranch) {
+                        replaceLabels.forEach { (from, to) ->
+                            if (it == from) {
+                                chunk.instructions[idx] = instr.copy(labelSymbol = to)
+                            }
+                            else {
+                                val actualPrefix = "$from."
+                                if (it.startsWith(actualPrefix))
+                                    chunk.instructions[idx] = instr.copy(labelSymbol = "$to.")
+                            }
+                        }
+                    }
+                }
+            }
+        }
    }

    private fun joinChunks(sub: IRSubroutine) {
@@ -85,7 +162,7 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
        if(sub.chunks.isEmpty())
            return

-        fun mayJoin(previous: IRCodeChunkBase, chunk: IRCodeChunkBase): Boolean {
+        fun mayJoinCodeChunks(previous: IRCodeChunkBase, chunk: IRCodeChunkBase): Boolean {
            if(chunk.label!=null)
                return false
            if(previous is IRCodeChunk && chunk is IRCodeChunk) {
@@ -102,12 +179,40 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
        chunks += sub.chunks[0]
        for(ix in 1 until sub.chunks.size) {
            val lastChunk = chunks.last()
-            if(mayJoin(lastChunk, sub.chunks[ix])) {
-                lastChunk.instructions += sub.chunks[ix].instructions
-                lastChunk.next = sub.chunks[ix].next
+            when(val candidate = sub.chunks[ix]) {
+                is IRCodeChunk -> {
+                    if(mayJoinCodeChunks(lastChunk, candidate)) {
+                        lastChunk.instructions += candidate.instructions
+                        lastChunk.next = candidate.next
+                        if(lastChunk is IRCodeChunk)
+                            lastChunk.appendSrcPositions(candidate.sourceLinesPositions)
+                    }
+                    else
+                        chunks += candidate
+                }
+                is IRInlineAsmChunk -> {
+                    if(candidate.label!=null)
+                        chunks += candidate
+                    else if(lastChunk.isEmpty()) {
+                        val label = lastChunk.label
+                        if(label!=null)
+                            chunks += IRInlineAsmChunk(label, candidate.assembly, candidate.isIR, candidate.next)
+                        else
+                            chunks += candidate
+                    }
+                }
+                is IRInlineBinaryChunk -> {
+                    if(candidate.label!=null)
+                        chunks += candidate
+                    else if(lastChunk.isEmpty()) {
+                        val label = lastChunk.label
+                        if(label!=null)
+                            chunks += IRInlineBinaryChunk(label, candidate.data, candidate.next)
+                        else
+                            chunks += candidate
+                    }
+                }
            }
-            else
-                chunks += sub.chunks[ix]
        }
        sub.chunks.clear()
        sub.chunks += chunks
@@ -119,8 +224,8 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
        indexedInstructions.reversed().forEach { (idx, ins) ->
            if(ins.opcode== Opcode.PUSH) {
                if(idx < chunk.instructions.size-1) {
-                    val insAfter = chunk.instructions[idx+1] as? IRInstruction
-                    if(insAfter!=null && insAfter.opcode == Opcode.POP) {
+                    val insAfter = chunk.instructions[idx+1]
+                    if(insAfter.opcode == Opcode.POP) {
                        if(ins.reg1==insAfter.reg1) {
                            chunk.instructions.removeAt(idx)
                            chunk.instructions.removeAt(idx)
@@ -143,16 +248,34 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
        indexedInstructions.reversed().forEach { (idx, ins) ->
            if(ins.opcode== Opcode.SEC || ins.opcode== Opcode.CLC) {
                if(idx < chunk.instructions.size-1) {
-                    val insAfter = chunk.instructions[idx+1] as? IRInstruction
-                    if(insAfter?.opcode == ins.opcode) {
+                    val insAfter = chunk.instructions[idx+1]
+                    if(insAfter.opcode == ins.opcode) {
                        chunk.instructions.removeAt(idx)
                        changed = true
                    }
-                    else if(ins.opcode== Opcode.SEC && insAfter?.opcode== Opcode.CLC) {
+                    else if(ins.opcode== Opcode.SEC && insAfter.opcode== Opcode.CLC) {
                        chunk.instructions.removeAt(idx)
                        changed = true
                    }
-                    else if(ins.opcode== Opcode.CLC && insAfter?.opcode== Opcode.SEC) {
+                    else if(ins.opcode== Opcode.CLC && insAfter.opcode== Opcode.SEC) {
+                        chunk.instructions.removeAt(idx)
+                        changed = true
+                    }
+                }
+            }
+
+            if(ins.opcode== Opcode.SEI || ins.opcode== Opcode.CLI) {
+                if(idx < chunk.instructions.size-1) {
+                    val insAfter = chunk.instructions[idx+1]
+                    if(insAfter.opcode == ins.opcode) {
+                        chunk.instructions.removeAt(idx)
+                        changed = true
+                    }
+                    else if(ins.opcode== Opcode.SEI && insAfter.opcode== Opcode.CLI) {
+                        chunk.instructions.removeAt(idx)
+                        changed = true
+                    }
+                    else if(ins.opcode== Opcode.CLI && insAfter.opcode== Opcode.SEI) {
                        chunk.instructions.removeAt(idx)
                        changed = true
                    }
@@ -174,10 +297,65 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
                    changed = true
                }
            }
+
            // remove useless RETURN
-            if(ins.opcode == Opcode.RETURN && idx>0) {
-                val previous = chunk.instructions[idx-1] as? IRInstruction
-                if(previous?.opcode in OpcodesThatJump) {
+            if(idx>0 && (ins.opcode == Opcode.RETURN || ins.opcode==Opcode.RETURNR)) {
+                val previous = chunk.instructions[idx-1]
+                if(previous.opcode in OpcodesThatJump) {
+                    chunk.instructions.removeAt(idx)
+                    changed = true
+                }
+            }
+
+            // replace subsequent opcodes that jump by just the first
+            if(idx>0 && (ins.opcode in OpcodesThatJump)) {
+                val previous = chunk.instructions[idx-1]
+                if(previous.opcode in OpcodesThatJump) {
+                    chunk.instructions.removeAt(idx)
+                    changed = true
+                }
+            }
+
+            // replace call + return --> jump
+            // This can no longer be done here on the IR level, with the current CALL opcode that encodes the full subroutine call setup.
+            // If machine code is ever generated from this IR, *that* should possibly optimize the JSR + RTS into a JMP.
+//            if(idx>0 && ins.opcode==Opcode.RETURN) {
+//                val previous = chunk.instructions[idx-1]
+//                if(previous.opcode==Opcode.CALL) {
+//                    chunk.instructions[idx-1] = IRInstruction(Opcode.JUMP, address = previous.address, labelSymbol = previous.labelSymbol, branchTarget = previous.branchTarget)
+//                    chunk.instructions.removeAt(idx)
+//                    changed = true
+//                }
+//            }
+        }
+        return changed
+    }
+
+    private fun removeNeedlessCompares(chunk: IRCodeChunk, indexedInstructions: List<IndexedValue<IRInstruction>>): Boolean {
+        // a CMPI with 0, after an instruction like LOAD that already sets the status bits, can be removed.
+        // but only if the instruction after it is not using the Carry bit because that won't be set by a LOAD instruction etc.
+        var changed = false
+        indexedInstructions.reversed().forEach { (idx, ins) ->
+            if(idx>0 && idx<(indexedInstructions.size-1) && ins.opcode==Opcode.CMPI && ins.immediate==0) {
+                val previous = indexedInstructions[idx-1].value
+                if(previous.reg1==ins.reg1) {
+                    if (previous.opcode in OpcodesThatSetStatusbitsIncludingCarry) {
+                        chunk.instructions.removeAt(idx)
+                        changed = true
+                    } else if (previous.opcode in OpcodesThatSetStatusbitsButNotCarry) {
+                        val next = indexedInstructions[idx + 1].value
+                        if (next.opcode !in OpcodesThatDependOnCarry) {
+                            chunk.instructions.removeAt(idx)
+                            changed = true
+                        }
+                    }
+                }
+            }
+
+            // a SNZ etc. whose target register is not used can be removed altogether
+            if(ins.opcode in OpcodesThatSetRegFromStatusbits) {
+                val usages = regUsages(ins.reg1!!)
+                if(usages.toList().sumOf { it.second } <= 1) {
                    chunk.instructions.removeAt(idx)
                    changed = true
                }
@@ -186,53 +364,67 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
        return changed
    }

+    private fun regUsages(register: Int): Map<IRCodeChunkBase, Int> {
+        val chunks = mutableMapOf<IRCodeChunkBase, Int>()
+        irprog.foreachSub { sub ->
+            sub.chunks.forEach { chunk ->
+                val used = chunk.usedRegisters()
+                val numUsages = used.readRegs.getOrDefault(register, 0) + used.writeRegs.getOrDefault(register, 0)
+                if(numUsages>0) {
+                    chunks[chunk] = numUsages
+                }
+            }
+        }
+        return chunks
+    }
+
    private fun removeUselessArithmetic(chunk: IRCodeChunk, indexedInstructions: List<IndexedValue<IRInstruction>>): Boolean {
        // note: this is hard to solve for the non-immediate instructions atm because the values are loaded into registers first
        var changed = false
        indexedInstructions.reversed().forEach { (idx, ins) ->
            when (ins.opcode) {
                Opcode.DIV, Opcode.DIVS, Opcode.MUL, Opcode.MOD -> {
-                    if (ins.value == 1) {
+                    if (ins.immediate == 1) {
                        chunk.instructions.removeAt(idx)
                        changed = true
                    }
                }
                Opcode.ADD, Opcode.SUB -> {
-                    if (ins.value == 1) {
+                    if (ins.immediate == 1) {
                        chunk.instructions[idx] = IRInstruction(
                            if (ins.opcode == Opcode.ADD) Opcode.INC else Opcode.DEC,
                            ins.type,
                            ins.reg1
                        )
                        changed = true
-                    } else if (ins.value == 0) {
+                    } else if (ins.immediate == 0) {
                        chunk.instructions.removeAt(idx)
                        changed = true
                    }
                }
                Opcode.AND -> {
-                    if (ins.value == 0) {
-                        chunk.instructions[idx] = IRInstruction(Opcode.LOAD, ins.type, reg1 = ins.reg1, value = 0)
+                    if (ins.immediate == 0) {
+                        chunk.instructions[idx] = IRInstruction(Opcode.LOAD, ins.type, reg1 = ins.reg1, immediate = 0)
                        changed = true
-                    } else if (ins.value == 255 && ins.type == IRDataType.BYTE) {
+                    } else if (ins.immediate == 255 && ins.type == IRDataType.BYTE) {
                        chunk.instructions.removeAt(idx)
                        changed = true
-                    } else if (ins.value == 65535 && ins.type == IRDataType.WORD) {
+                    } else if (ins.immediate == 65535 && ins.type == IRDataType.WORD) {
                        chunk.instructions.removeAt(idx)
                        changed = true
                    }
                }
                Opcode.OR -> {
-                    if (ins.value == 0) {
+                    if (ins.immediate == 0) {
                        chunk.instructions.removeAt(idx)
                        changed = true
-                    } else if ((ins.value == 255 && ins.type == IRDataType.BYTE) || (ins.value == 65535 && ins.type == IRDataType.WORD)) {
-                        chunk.instructions[idx] = IRInstruction(Opcode.LOAD, ins.type, reg1 = ins.reg1, value = ins.value)
+                    } else if ((ins.immediate == 255 && ins.type == IRDataType.BYTE) || (ins.immediate == 65535 && ins.type == IRDataType.WORD)) {
+                        chunk.instructions[idx] = IRInstruction(Opcode.LOAD, ins.type, reg1 = ins.reg1, immediate = ins.immediate)
                        changed = true
                    }
                }
                Opcode.XOR -> {
-                    if (ins.value == 0) {
+                    if (ins.immediate == 0) {
                        chunk.instructions.removeAt(idx)
                        changed = true
                    }
@@ -257,15 +449,31 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
    private fun removeDoubleLoadsAndStores(chunk: IRCodeChunk, indexedInstructions: List<IndexedValue<IRInstruction>>): Boolean {
        var changed = false
        indexedInstructions.forEach { (idx, ins) ->
+            if(ins.opcode==Opcode.STOREM) {
+                val prev = indexedInstructions[idx-1].value
+                if(prev.opcode==Opcode.LOADM) {
+                    // loadm.X rX,something | storem.X rX,something ?? -> get rid of the store.
+                    if(ins.labelSymbol!=null && ins.labelSymbol==prev.labelSymbol && ins.labelSymbolOffset==prev.labelSymbolOffset) {
+                        changed=true
+                        chunk.instructions.removeAt(idx)
+                    }
+                    else if(ins.address!=null && ins.address==prev.address) {
+                        changed=true
+                        chunk.instructions.removeAt(idx)
+                    }
+                }
+            }

-            // TODO: detect multiple loads to the same target registers, only keep first (if source is not I/O memory)
-            // TODO: detect multiple stores to the same target, only keep first (if target is not I/O memory)
-            // TODO: detect multiple float ffrom/fto to the same target, only keep first
-            // TODO: detect multiple sequential rnd with same reg1, only keep one
-            // TODO: detect subsequent same xors/nots/negs, remove the pairs completely as they cancel out
-            // TODO: detect multiple same ands, ors; only keep first
-            // TODO: (hard) detect multiple registers being assigned the same value (and not changed) - use only 1 of them
+/*
+    Possible other optimizations:
+            // detect multiple loads to the same target registers, only keep first (if source is not I/O memory)
+            // detect multiple stores to the same target, only keep first (if target is not I/O memory)
+            // detect multiple float ffrom/fto to the same target, only keep first
+            // detect subsequent same xors/nots/negs, remove the pairs completely as they cancel out
+            // detect multiple same ands, ors; only keep first
+            // detect multiple registers being assigned the same value (and not changed) - use only 1 of them  (hard!)
            // ...
+*/
        }
        return changed
    }
@@ -1,38 +1,21 @@
 package prog8.codegen.intermediate

 import prog8.code.core.IErrorReporter
-import prog8.code.core.SourceCode.Companion.libraryFilePrefix
 import prog8.intermediate.*


-internal class IRUnusedCodeRemover(private val irprog: IRProgram, private val errors: IErrorReporter) {
+class IRUnusedCodeRemover(
+    private val irprog: IRProgram,
+    private val errors: IErrorReporter
+) {
    fun optimize(): Int {
-        val allLabeledChunks = mutableMapOf<String, IRCodeChunkBase>()
-
-        irprog.blocks.asSequence().flatMap { it.children.filterIsInstance<IRSubroutine>() }.forEach { sub ->
-            sub.chunks.forEach { chunk ->
-                chunk.label?.let { allLabeledChunks[it] = chunk }
-            }
-        }
-
-        var numRemoved = removeSimpleUnlinked(allLabeledChunks) + removeUnreachable(allLabeledChunks)
-
-        // remove empty subs
-        irprog.blocks.forEach { block ->
-            block.children.filterIsInstance<IRSubroutine>().reversed().forEach { sub ->
-                if(sub.isEmpty()) {
-                    if(!sub.position.file.startsWith(libraryFilePrefix))
-                        errors.warn("unused subroutine ${sub.label}", sub.position)
-                    block.children.remove(sub)
-                    numRemoved++
-                }
-            }
-        }
+        var numRemoved = removeUnusedSubroutines() + removeUnusedAsmSubroutines()

        // remove empty blocks
        irprog.blocks.reversed().forEach { block ->
            if(block.isEmpty()) {
                irprog.blocks.remove(block)
+                pruneSymboltable(block.label)
                numRemoved++
            }
        }
@@ -40,9 +23,144 @@ internal class IRUnusedCodeRemover(private val irprog: IRProgram, private val er
        return numRemoved
    }

+    private fun pruneSymboltable(blockLabel: String) {
+        // we could clean up the SymbolTable as well, but ONLY if these symbols aren't referenced somewhere still in an instruction or variable initializer value
+        val prefix = "$blockLabel."
+        val blockVars = irprog.st.allVariables().filter { it.name.startsWith(prefix) }
+        blockVars.forEach { stVar ->
+            irprog.allSubs().flatMap { it.chunks }.forEach { chunk ->
+                chunk.instructions.forEach { ins ->
+                    if(ins.labelSymbol == stVar.name) {
+                        return  // symbol occurs in an instruction
+                    }
+                }
+            }
+
+            irprog.st.allVariables().forEach { variable ->
+                val initValue = variable.onetimeInitializationArrayValue
+                if(!initValue.isNullOrEmpty()) {
+                    if(initValue.any {
+                        it.addressOfSymbol?.startsWith(blockLabel)==true
+                    })
+                        return   // symbol occurs in an initializer value (address-of this symbol)_
+                }
+            }
+        }
+
+        irprog.st.removeTree(blockLabel)
+    }
+
+    private fun removeUnusedSubroutines(): Int {
+        val allLabeledChunks = mutableMapOf<String, IRCodeChunkBase>()
+        irprog.foreachCodeChunk { chunk ->
+            chunk.label?.let { allLabeledChunks[it] = chunk }
+        }
+
+        var numRemoved = removeSimpleUnlinked(allLabeledChunks) + removeUnreachable(allLabeledChunks)
+        irprog.blocks.forEach { block ->
+            block.children.filterIsInstance<IRSubroutine>().reversed().forEach { sub ->
+                if(sub.isEmpty()) {
+                    if(!block.options.ignoreUnused) {
+                        errors.info("unused subroutine '${sub.label}'", sub.position)
+                    }
+                    block.children.remove(sub)
+                    irprog.st.removeTree(sub.label)
+                    numRemoved++
+                }
+            }
+        }
+
+        return numRemoved
+    }
+
+    private fun removeUnusedAsmSubroutines(): Int {
+        val allLabeledAsmsubs = irprog.blocks.asSequence().flatMap { it.children.filterIsInstance<IRAsmSubroutine>() }
+            .associateBy { it.label }
+
+        var numRemoved = removeSimpleUnlinkedAsmsubs(allLabeledAsmsubs)
+        irprog.blocks.forEach { block ->
+            block.children.filterIsInstance<IRAsmSubroutine>().reversed().forEach { sub ->
+                if(sub.isEmpty()) {
+                    if(!block.options.ignoreUnused) {
+                        errors.info("unused subroutine '${sub.label}'", sub.position)
+                    }
+                    block.children.remove(sub)
+                    irprog.st.removeTree(sub.label)
+                    numRemoved++
+                }
+            }
+        }
+
+        return numRemoved
+    }
+
+    private fun removeSimpleUnlinkedAsmsubs(allSubs: Map<String, IRAsmSubroutine>): Int {
+        val linkedAsmSubs = mutableSetOf<IRAsmSubroutine>()
+
+        // TODO: asmsubs in library modules are never removed, we can't really tell here if they're actually being called or not...
+
+        // check if asmsub is called from another asmsub
+        irprog.blocks.asSequence().forEach { block ->
+            block.children.filterIsInstance<IRAsmSubroutine>().forEach { sub ->
+                if (block.options.forceOutput || block.library)
+                    linkedAsmSubs += sub
+                if (sub.asmChunk.isNotEmpty()) {
+                    allSubs.forEach { (label, asmsub) ->
+                        if (sub.asmChunk.assembly.contains(label))
+                            linkedAsmSubs += asmsub
+                    }
+                }
+                val inlineAsm = sub.asmChunk.next as? IRInlineAsmChunk
+                if(inlineAsm!=null) {
+                    allSubs.forEach { (label, asmsub) ->
+                        if (inlineAsm.assembly.contains(label))
+                            linkedAsmSubs += asmsub
+                    }
+                }
+            }
+        }
+
+        // check if asmsub is linked or called from another regular subroutine
+        irprog.foreachCodeChunk { chunk ->
+            chunk.instructions.forEach {
+                it.labelSymbol?.let { label -> allSubs[label]?.let { cc -> linkedAsmSubs += cc } }
+                // note: branchTarget can't yet point to another IRAsmSubroutine, so do nothing when it's set
+            }
+        }
+
+        return removeUnlinkedAsmsubs(linkedAsmSubs)
+    }
+
+    private fun removeUnlinkedAsmsubs(linkedAsmSubs: Set<IRAsmSubroutine>): Int {
+        var numRemoved = 0
+        irprog.blocks.asSequence().forEach { block ->
+            block.children.withIndex().reversed().forEach { (index, child) ->
+                if(child is IRAsmSubroutine && child !in linkedAsmSubs) {
+                    block.children.removeAt(index)
+                    numRemoved++
+                }
+            }
+        }
+        return numRemoved
+    }
+
    private fun removeUnreachable(allLabeledChunks: MutableMap<String, IRCodeChunkBase>): Int {
-        val entrypointSub = irprog.blocks.single { it.name=="main" }.children.single { it is IRSubroutine && it.label=="main.start" }
+        val entrypointSub = irprog.blocks.single { it.label=="main" }
+            .children.single { it is IRSubroutine && it.label=="main.start" }
        val reachable = mutableSetOf((entrypointSub as IRSubroutine).chunks.first())
+        reachable.add(irprog.globalInits)
+
+        // all chunks referenced in array initializer values are also 'reachable':
+        irprog.st.allVariables()
+            .filter { !it.uninitialized }
+            .forEach {
+                it.onetimeInitializationArrayValue?.let { array ->
+                    array.forEach {elt ->
+                        if(elt.addressOfSymbol!=null && irprog.st.lookup(elt.addressOfSymbol!!)==null)
+                            reachable.add(irprog.getChunkWithLabel(elt.addressOfSymbol!!))
+                    }
+                }
+            }

        fun grow() {
            val new = mutableSetOf<IRCodeChunkBase>()
@@ -50,7 +168,13 @@ internal class IRUnusedCodeRemover(private val irprog: IRProgram, private val er
                it.next?.let { next -> new += next }
                it.instructions.forEach { instr ->
                    if (instr.branchTarget == null)
-                        instr.labelSymbol?.let { label -> allLabeledChunks[label]?.let { chunk -> new += chunk } }
+                        instr.labelSymbol?.let { label ->
+                            val chunk = allLabeledChunks[label] ?: allLabeledChunks[label.substringBeforeLast('.')]
+                            if(chunk!=null)
+                                new+=chunk
+                            else
+                                allLabeledChunks[label]?.let { new += it }
+                        }
                    else
                        new += instr.branchTarget!!
                }
@@ -72,29 +196,48 @@ internal class IRUnusedCodeRemover(private val irprog: IRProgram, private val er
    private fun removeSimpleUnlinked(allLabeledChunks: Map<String, IRCodeChunkBase>): Int {
        val linkedChunks = mutableSetOf<IRCodeChunkBase>()

-        irprog.blocks.asSequence().flatMap { it.children.filterIsInstance<IRSubroutine>() }.forEach { sub ->
-            sub.chunks.forEach { chunk ->
-                chunk.next?.let { next -> linkedChunks += next }
-                chunk.instructions.forEach {
-                    if(it.branchTarget==null) {
-                        it.labelSymbol?.let { label -> allLabeledChunks[label]?.let { cc -> linkedChunks += cc } }
-                    } else {
-                        linkedChunks += it.branchTarget!!
+        // all chunks referenced in array initializer values are linked as well!:
+        irprog.st.allVariables()
+            .filter { !it.uninitialized }
+            .forEach {
+                it.onetimeInitializationArrayValue?.let { array ->
+                    array.forEach {elt ->
+                        if(elt.addressOfSymbol!=null && irprog.st.lookup(elt.addressOfSymbol!!)==null)
+                            linkedChunks += irprog.getChunkWithLabel(elt.addressOfSymbol!!)
                    }
                }
-                if (chunk.label == "main.start")
-                    linkedChunks += chunk
+            }
+
+        irprog.foreachCodeChunk { chunk ->
+            chunk.next?.let { next -> linkedChunks += next }
+            chunk.instructions.forEach {
+                if(it.branchTarget==null) {
+                    it.labelSymbol?.let { label -> allLabeledChunks[label]?.let { cc -> linkedChunks += cc } }
+                } else {
+                    linkedChunks += it.branchTarget!!
+                }
+            }
+            if (chunk.label == "main.start")
+                linkedChunks += chunk
+        }
+
+        // make sure that chunks that are only used as a prefix of a label, are also marked as linked
+        linkedChunks.toList().forEach { chunk ->
+            chunk.instructions.forEach {
+                if(it.labelSymbol!=null) {
+                    val chunkName = it.labelSymbol!!.substringBeforeLast('.')
+                    allLabeledChunks[chunkName]?.let { linkedChunks+=it }
+                }
            }
        }

+        linkedChunks.add(irprog.globalInits)
        return removeUnlinkedChunks(linkedChunks)
    }

-    private fun removeUnlinkedChunks(
-        linkedChunks: MutableSet<IRCodeChunkBase>
-    ): Int {
+    private fun removeUnlinkedChunks(linkedChunks: Set<IRCodeChunkBase>): Int {
        var numRemoved = 0
-        irprog.blocks.asSequence().flatMap { it.children.filterIsInstance<IRSubroutine>() }.forEach { sub ->
+        irprog.foreachSub { sub ->
            sub.chunks.withIndex().reversed().forEach { (index, chunk) ->
                if (chunk !in linkedChunks) {
                    if (chunk === sub.chunks[0]) {
@@ -0,0 +1,47 @@
+package prog8.codegen.intermediate
+
+import prog8.code.ast.*
+
+
+internal fun makeAllNodenamesScoped(program: PtProgram) {
+    val renames = mutableListOf<Pair<PtNamedNode, String>>()
+    fun recurse(node: PtNode) {
+        node.children.forEach {
+            if(it is PtNamedNode)
+                renames.add(it to it.scopedName)
+            recurse(it)
+        }
+    }
+    recurse(program)
+    renames.forEach { it.first.name = it.second }
+}
+
+internal fun moveAllNestedSubroutinesToBlockScope(program: PtProgram) {
+    val movedSubs = mutableListOf<Pair<PtBlock, PtSub>>()
+    val removedSubs = mutableListOf<Pair<PtSub, PtSub>>()
+
+    fun moveToBlock(block: PtBlock, parent: PtSub, asmsub: PtAsmSub) {
+        block.add(asmsub)
+        parent.children.remove(asmsub)
+    }
+
+    fun moveToBlock(block: PtBlock, parent: PtSub, sub: PtSub) {
+        sub.children.filterIsInstance<PtSub>().forEach { subsub -> moveToBlock(block, sub, subsub) }
+        sub.children.filterIsInstance<PtAsmSub>().forEach { asmsubsub -> moveToBlock(block, sub, asmsubsub) }
+        movedSubs += Pair(block, sub)
+        removedSubs += Pair(parent, sub)
+    }
+
+    program.allBlocks().forEach { block ->
+        block.children.toList().forEach {
+            if (it is PtSub) {
+                // Only regular subroutines can have nested subroutines.
+                it.children.filterIsInstance<PtSub>().forEach { subsub -> moveToBlock(block, it, subsub) }
+                it.children.filterIsInstance<PtAsmSub>().forEach { asmsubsub -> moveToBlock(block, it, asmsubsub) }
+            }
+        }
+    }
+
+    removedSubs.forEach { (parent, sub) -> parent.children.remove(sub) }
+    movedSubs.forEach { (block, sub) -> block.add(sub) }
+}
@@ -1,10 +1,7 @@
 package prog8.codegen.intermediate

-import prog8.code.core.AssemblyError
-import prog8.intermediate.SyscallRegisterBase
-
 internal class RegisterPool {
-    // reserve 0,1,2 for return values of subroutine calls and syscalls
+    // reserve 0,1,2 for return values of subroutine calls and syscalls in IR assembly code
    private var firstFree: Int=3
    private var firstFreeFloat: Int=3

@@ -14,16 +11,12 @@ internal class RegisterPool {
    fun nextFree(): Int {
        val result = firstFree
        firstFree++
-        if(firstFree >= SyscallRegisterBase)
-            throw AssemblyError("out of virtual registers (int)")
        return result
    }

    fun nextFreeFloat(): Int {
        val result = firstFreeFloat
        firstFreeFloat++
-        if(firstFreeFloat >= SyscallRegisterBase)
-            throw AssemblyError("out of virtual registers (fp)")
        return result
    }
 }