correct version

not separate
last attempt for hash build step
2026-10-22 20:02:27 +00:00 · 2024-03-21 20:15:54 +01:00 · 2024-03-21 20:07:44 +01:00 · 2024-03-21 20:04:07 +01:00 · 2024-03-21 19:32:16 +01:00 · 2024-03-20 22:46:18 +01:00
413 changed files with 41259 additions and 23936 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 +10,42 @@ 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

      - name: Build and test with Gradle
        run: ./gradlew build shadowJar --no-daemon
-
+        
      - 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
+
+      - name: Calculate hash
+        uses: MCJack123/ghaction-generate-release-hashes@v4
+        if: github.event_name == 'release'
+        with:
+          get-assets: true
+          hash-type: sha256
+          file-name: hashes.txt
+
+      - name: Upload hashes
+        uses: actions/upload-artifact@v4
+        if: github.event_name == 'release'
+        with:
+          name: Artifact Hashes
+          path: hashes.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" />
@@ -4,6 +4,6 @@
    <option name="jvmTarget" value="11" />
  </component>
  <component name="KotlinJpsPluginSettings">
-    <option name="version" value="1.8.20-release-327" />
+    <option name="version" value="1.9.20" />
  </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-jdk8:1.9.22" />
    <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-jdk8/1.9.22/kotlin-stdlib-jdk8-1.9.22.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-jdk7/1.9.22/kotlin-stdlib-jdk7-1.9.22.jar!/" />
    </CLASSES>
-    <JAVADOC />
+    <JAVADOC>
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.9.22/kotlin-stdlib-jdk8-1.9.22-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.9.22/kotlin-stdlib-1.9.22-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0-javadoc.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.9.22/kotlin-stdlib-jdk7-1.9.22-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-jdk8/1.9.22/kotlin-stdlib-jdk8-1.9.22-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.9.22/kotlin-stdlib-1.9.22-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0-sources.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.9.22/kotlin-stdlib-jdk7-1.9.22-sources.jar!/" />
    </SOURCES>
  </library>
 </component>
@@ -1,13 +1,13 @@
 <component name="libraryTable">
  <library name="antlr.antlr4" type="repository">
-    <properties maven-id="org.antlr:antlr4:4.12.0">
+    <properties maven-id="org.antlr:antlr4:4.13.1">
      <exclude>
        <dependency maven-id="com.ibm.icu:icu4j" />
      </exclude>
    </properties>
    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4/4.12.0/antlr4-4.12.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4-runtime/4.12.0/antlr4-runtime-4.12.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4/4.13.1/antlr4-4.13.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/antlr/antlr4-runtime/4.13.1/antlr4-runtime-4.13.1.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!/" />
@@ -1,25 +0,0 @@
-<component name="libraryTable">
-  <library name="github.hypfvieh.dbus.java" type="repository">
-    <properties maven-id="com.github.hypfvieh:dbus-java:3.3.2" />
-    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/hypfvieh/dbus-java/3.3.2/dbus-java-3.3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jnr-unixsocket/0.38.17/jnr-unixsocket-0.38.17.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jnr-ffi/2.2.11/jnr-ffi-2.2.11.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jffi/1.3.9/jffi-1.3.9.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jffi/1.3.9/jffi-1.3.9-native.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/ow2/asm/asm/9.2/asm-9.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/ow2/asm/asm-commons/9.2/asm-commons-9.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/ow2/asm/asm-analysis/9.2/asm-analysis-9.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/ow2/asm/asm-tree/9.2/asm-tree-9.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/ow2/asm/asm-util/9.2/asm-util-9.2.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/0.10.3/jnr-constants-0.10.3.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jnr-enxio/0.32.13/jnr-enxio-0.32.13.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/jnr/jnr-posix/3.1.15/jnr-posix-3.1.15.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/slf4j/slf4j-api/1.7.36/slf4j-api-1.7.36.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>
@@ -1,10 +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 +1,21 @@
 <component name="libraryTable">
  <library name="io.kotest.assertions.core.jvm" type="repository">
-    <properties maven-id="io.kotest:kotest-assertions-core-jvm:5.5.5" />
+    <properties maven-id="io.kotest:kotest-assertions-core-jvm:5.8.0" />
    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.5.5/kotest-assertions-core-jvm-5.5.5.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-assertions-shared-jvm/5.5.5/kotest-assertions-shared-jvm-5.5.5.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.8.0/kotest-assertions-core-jvm-5.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.8.10/kotlin-stdlib-jdk8-1.8.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.8.10/kotlin-stdlib-1.8.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.8.10/kotlin-stdlib-jdk7-1.8.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.8.0/kotest-assertions-shared-jvm-5.8.0.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/1.2.0/opentest4j-1.2.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.6.21/kotlin-stdlib-common-1.6.21.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.6.4/kotlinx-coroutines-jdk8-1.6.4.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.6.21/kotlin-reflect-1.6.21.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.5.5/kotest-common-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.5.5/kotest-assertions-api-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.4/kotlinx-coroutines-core-jvm-1.6.4.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-common/1.8.10/kotlin-stdlib-common-1.8.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.7.0/kotlinx-coroutines-jdk8-1.7.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.8.10/kotlin-reflect-1.8.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.8.0/kotest-common-jvm-5.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.8.0/kotest-assertions-api-jvm-5.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.7.0/kotlinx-coroutines-core-jvm-1.7.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/23.0.0/annotations-23.0.0.jar!/" />
    </CLASSES>
    <JAVADOC />
    <SOURCES />
@@ -1,24 +0,0 @@
-<component name="libraryTable">
-  <library name="io.kotest.property.jvm" type="repository">
-    <properties maven-id="io.kotest:kotest-property-jvm:5.5.5" />
-    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-property-jvm/5.5.5/kotest-property-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.5.5/kotest-common-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.5.5/kotest-assertions-shared-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.5.5/kotest-assertions-api-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.6.4/kotlinx-coroutines-jdk8-1.6.4.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.6.21/kotlin-stdlib-common-1.6.21.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/github/curious-odd-man/rgxgen/1.4/rgxgen-1.4.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://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.4/kotlinx-coroutines-core-jvm-1.6.4.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/github/java-diff-utils/java-diff-utils/4.12/java-diff-utils-4.12.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>
@@ -1,55 +1,42 @@
 <component name="libraryTable">
  <library name="io.kotest.runner.junit5.jvm" type="repository">
-    <properties maven-id="io.kotest:kotest-runner-junit5-jvm:5.5.5" />
+    <properties maven-id="io.kotest:kotest-runner-junit5-jvm:5.8.0" />
    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-runner-junit5-jvm/5.5.5/kotest-runner-junit5-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-api-jvm/5.5.5/kotest-framework-api-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-test-jvm/1.6.4/kotlinx-coroutines-test-jvm-1.6.4.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.5.5/kotest-assertions-shared-jvm-5.5.5.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-runner-junit5-jvm/5.8.0/kotest-runner-junit5-jvm-5.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-api-jvm/5.8.0/kotest-framework-api-jvm-5.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.8.0/kotest-assertions-shared-jvm-5.8.0.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/jetbrains/kotlin/kotlin-stdlib-common/1.6.21/kotlin-stdlib-common-1.6.21.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.5.5/kotest-common-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-engine-jvm/5.5.5/kotest-framework-engine-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/github/classgraph/classgraph/4.8.154/classgraph-4.8.154.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-test-jvm/1.7.0/kotlinx-coroutines-test-jvm-1.7.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.8.0/kotest-common-jvm-5.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-engine-jvm/5.8.0/kotest-framework-engine-jvm-5.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/github/classgraph/classgraph/4.8.162/classgraph-4.8.162.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/1.6.4/kotlinx-coroutines-debug-1.6.4.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/1.7.0/kotlinx-coroutines-debug-1.7.0.jar!/" />
      <root url="jar://$MAVEN_REPOSITORY$/net/java/dev/jna/jna/5.9.0/jna-5.9.0.jar!/" />
      <root url="jar://$MAVEN_REPOSITORY$/net/java/dev/jna/jna-platform/5.9.0/jna-platform-5.9.0.jar!/" />
      <root url="jar://$MAVEN_REPOSITORY$/net/bytebuddy/byte-buddy/1.10.9/byte-buddy-1.10.9.jar!/" />
      <root url="jar://$MAVEN_REPOSITORY$/net/bytebuddy/byte-buddy-agent/1.10.9/byte-buddy-agent-1.10.9.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-discovery-jvm/5.5.5/kotest-framework-discovery-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.5.5/kotest-assertions-core-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.6.4/kotlinx-coroutines-jdk8-1.6.4.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.5.5/kotest-assertions-api-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-extensions-jvm/5.5.5/kotest-extensions-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-jvm/1.13.1/mockk-jvm-1.13.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-dsl-jvm/1.13.1/mockk-dsl-jvm-1.13.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-agent-jvm/1.13.1/mockk-agent-jvm-1.13.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/objenesis/objenesis/3.2/objenesis-3.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-agent-api-jvm/1.13.1/mockk-agent-api-jvm-1.13.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-core-jvm/1.13.1/mockk-core-jvm-1.13.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/slf4j/slf4j-api/1.7.36/slf4j-api-1.7.36.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/junit/junit/4.13.2/junit-4.13.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter/5.8.2/junit-jupiter-5.8.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-params/5.8.2/junit-jupiter-params-5.8.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-engine/5.8.2/junit-jupiter-engine-5.8.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core/1.6.4/kotlinx-coroutines-core-1.6.4.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-concurrency-jvm/5.5.5/kotest-framework-concurrency-jvm-5.5.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.4/kotlinx-coroutines-core-jvm-1.6.4.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://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-discovery-jvm/5.8.0/kotest-framework-discovery-jvm-5.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.8.0/kotest-assertions-core-jvm-5.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.7.0/kotlinx-coroutines-jdk8-1.7.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.8.0/kotest-assertions-api-jvm-5.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-extensions-jvm/5.8.0/kotest-extensions-jvm-5.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-concurrency-jvm/5.8.0/kotest-framework-concurrency-jvm-5.8.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.7.0/kotlinx-coroutines-core-jvm-1.7.0.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-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://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.8.10/kotlin-stdlib-jdk8-1.8.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.8.10/kotlin-stdlib-1.8.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.8.10/kotlin-stdlib-jdk7-1.8.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.8.10/kotlin-stdlib-common-1.8.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.8.10/kotlin-reflect-1.8.10.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:0.3.5" />
+    <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/0.3.5/kotlinx-cli-jvm-0.3.5.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:1.1.20" />
    <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/1.1.20/kotlin-result-jvm-1.1.20.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:2.0.7" />
-    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/slf4j/slf4j-simple/2.0.7/slf4j-simple-2.0.7.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/slf4j/slf4j-api/2.0.7/slf4j-api-2.0.7.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>
@@ -1,18 +0,0 @@
-<component name="libraryTable">
-  <library name="takes" type="repository">
-    <properties maven-id="org.takes:takes:1.24.4" />
-    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/takes/takes/1.24.4/takes-1.24.4.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/cactoos/cactoos/0.54.0/cactoos-0.54.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/javax/xml/bind/jaxb-api/2.4.0-b180830.0359/jaxb-api-2.4.0-b180830.0359.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/javax/activation/javax.activation-api/1.2.0/javax.activation-api-1.2.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/sun/xml/bind/jaxb-core/4.0.0/jaxb-core-4.0.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/jakarta/xml/bind/jakarta.xml.bind-api/4.0.0/jakarta.xml.bind-api-4.0.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/jakarta/activation/jakarta.activation-api/2.1.0/jakarta.activation-api-2.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/eclipse/angus/angus-activation/1.0.0/angus-activation-1.0.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/com/sun/xml/bind/jaxb-impl/4.0.0/jaxb-impl-4.0.0.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>
@@ -16,6 +16,9 @@
      </list>
    </option>
  </component>
+  <component name="Black">
+    <option name="sdkName" value="Python 3.11" />
+  </component>
  <component name="FrameworkDetectionExcludesConfiguration">
    <type id="Python" />
  </component>
@@ -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" />
@@ -9,17 +9,19 @@ version: 2
 build:
  os: ubuntu-22.04
  tools:
-    python: "3.11"
-
-# 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 +10,35 @@ 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).
+- 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 +51,8 @@ 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. It's possible to write games purely in Prog8, and even certain raster interrupt 'demoscene' effects.
 - 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)
@@ -35,6 +60,7 @@ 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
@@ -59,6 +85,8 @@ 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)


@@ -26,16 +26,16 @@ 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:1.1.20"
 }

 sourceSets {
    main {
        java {
-            srcDirs = ["${project.projectDir}/src"]
+            srcDir "${project.projectDir}/src"
        }
        resources {
-            srcDirs = ["${project.projectDir}/res"]
+            srcDir "${project.projectDir}/res"
        }
    }
 }
@@ -80,6 +80,16 @@ class SymbolTable(astProgram: PtProgram) : StNode(astProgram.name, StNodeType.GL
    }

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


@@ -185,14 +195,11 @@ 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)
@@ -203,8 +210,7 @@ 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,
@@ -215,6 +221,7 @@ class StMemVar(name: String,
    StNode(name, StNodeType.MEMVAR, astNode) {

    init{
+        require(dt!=DataType.BOOL && dt!=DataType.ARRAY_BOOL)
        if(dt in ArrayDatatypes || dt == DataType.STR)
            require(length!=null) { "memory mapped array or string must have known length" }
    }
@@ -226,16 +233,15 @@ 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) :
@@ -245,7 +251,7 @@ 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>
@@ -26,8 +26,6 @@ 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, 128u, Position.DUMMY),
-                PtMemMapped("P8ESTACK_HI", DataType.ARRAY_UB, options.compTarget.machine.ESTACK_HI, 128u, Position.DUMMY)
            ).forEach {
                it.parent = program
                st.add(StMemVar(it.name, it.type, it.address, it.arraySize?.toInt(), it))
@@ -40,14 +38,9 @@ class SymbolTableMaker(private val program: PtProgram, private val options: Comp
    private fun addToSt(node: PtNode, scope: Stack<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 +74,9 @@ 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 +91,9 @@ 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 -> {
@@ -130,9 +125,14 @@ class SymbolTableMaker(private val program: PtProgram, private val options: Comp
    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 +175,7 @@ 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)
 }


@@ -1,19 +1,14 @@
 package prog8.code.ast

-import prog8.code.core.DataType
-import prog8.code.core.Encoding
-import prog8.code.core.NumericDatatypes
-import prog8.code.core.Position
+import prog8.code.core.*
 import java.util.*
 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) {
@@ -27,14 +22,32 @@ 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 PtAddressOf -> {
+                if(other !is PtAddressOf)
+                    return false
+                if (other.type!==type || !(other.identifier isSameAs identifier))
+                    return false
+                if(other.children.size!=children.size)
+                    return false
+                if(children.size==1)
+                    return true
+                return arrayIndexExpr!! isSameAs other.arrayIndexExpr!!
+            }
+            is PtArrayIndexer -> other is PtArrayIndexer && other.type==type && other.variable isSameAs variable && other.index isSameAs index && other.splitWords==splitWords
+            is PtBinaryExpression -> {
+                if(other !is PtBinaryExpression || other.operator!=operator)
+                    false
+                else if(operator in AssociativeOperators)
+                    (other.left isSameAs left && other.right isSameAs right) || (other.left isSameAs right && other.right isSameAs left)
+                else
+                    other.left isSameAs left && other.right isSameAs right
+            }
            is PtContainmentCheck -> other is PtContainmentCheck && other.type==type && other.element isSameAs element && other.iterable isSameAs iterable
            is PtIdentifier -> other is PtIdentifier && other.type==type && other.name==name
            is PtMachineRegister -> other is PtMachineRegister && 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
@@ -51,13 +64,13 @@ 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) {
@@ -65,12 +78,18 @@ 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 PtMemoryByte -> address is PtNumber || address is PtIdentifier
+            is PtBool -> true
            is PtNumber -> true
            is PtPrefix -> value.isSimple()
            is PtRange -> true
@@ -97,6 +116,7 @@ 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))
@@ -108,18 +128,29 @@ 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
 }


 class PtArrayIndexer(elementType: DataType, position: Position): PtExpression(elementType, position) {
    val variable: PtIdentifier
-        get() = children[0] as PtIdentifier
+        get() {
+            require((children[0] as? PtIdentifier)?.type in ArrayDatatypes+DataType.STR)        // TODO remove
+            return 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)
    }
 }

@@ -153,15 +184,21 @@ 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) {
+class PtContainmentCheck(position: Position): PtExpression(DataType.BOOL, position) {
    val element: PtExpression
        get() = children[0] as PtExpression
    val iterable: PtIdentifier
@@ -198,6 +235,27 @@ class PtMemoryByte(position: Position) : PtExpression(DataType.UBYTE, position)
 }


+class PtBool(val value: Boolean, position: Position) : PtExpression(DataType.BOOL, position) {
+
+    companion object {
+        fun fromNumber(number: Number, position: Position): PtBool =
+            PtBool(if(number==0.0) false else true, 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 {
@@ -207,11 +265,11 @@ 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")
        }
    }

@@ -220,7 +278,10 @@ class PtNumber(type: DataType, val number: Double, position: Position) : PtExpre
    override fun equals(other: Any?): Boolean {
        if(other==null || other !is PtNumber)
            return false
-        return number==other.number
+        else if(type!=DataType.BOOL && other.type!=DataType.BOOL)
+            return number==other.number
+        else
+            return type==other.type && number==other.number
    }

    operator fun compareTo(other: PtNumber): Int = number.compareTo(other.number)
@@ -234,8 +295,7 @@ 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" }
    }
 }

@@ -297,5 +357,5 @@ class PtTypeCast(type: DataType, position: Position) : PtExpression(type, positi
 class PtMachineRegister(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
@@ -15,9 +15,14 @@ fun printAst(root: PtNode, skipLibraries: Boolean, output: (text: String) -> Uni
            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} ${type(node.type)}"
            is PtBuiltinFunctionCall -> {
                val str = if(node.void) "void " else ""
@@ -35,6 +40,7 @@ fun printAst(root: PtNode, skipLibraries: Boolean, output: (text: String) -> Uni
                val numstr = if(node.type == DataType.FLOAT) node.number.toString() else node.number.toHex()
                "$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, skipLibraries: Boolean, output: (text: String) -> Uni
                    "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 ${node.parameters.size} PARAMS..."
+                val params = node.parameters.map {
+                                val register = it.first.registerOrPair
+                                val statusflag = it.first.statusflag
+                                "${it.second.type} ${it.second.name} @${register ?: statusflag}"
+                            }.joinToString(", ")
                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 {
+                    "-> ${node.returns.map {
+                        val register = it.first.registerOrPair
+                        val statusflag = it.first.statusflag
+                        "${it.second} @${register ?: statusflag}"}
+                        .joinToString(", ")
+                    }"
+                }
                val str = if (node.inline) "inline " else ""
                if(node.address==null) {
                    str + "asmsub ${node.name}($params) $clobbers $returns"
@@ -70,12 +85,16 @@ fun printAst(root: PtNode, skipLibraries: Boolean, output: (text: String) -> Uni
                }
            }
            is PtBlock -> {
-                val addr = if(node.address==null) "" else "@${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, skipLibraries: Boolean, output: (text: String) -> Uni
                }
            }
            is PtSub -> {
-                val params = if (node.parameters.isEmpty()) "" else "...TODO ${node.parameters.size} PARAMS..."
+                val params = node.parameters.map { "${it.type} ${it.name}" }.joinToString(", ")
                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, skipLibraries: Boolean, output: (text: String) -> Uni
                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, skipLibraries: Boolean, output: (text: String) -> Uni
                else
                    "->"
            }
-            else -> throw InternalCompilerException("unrecognised ast node $node")
        }
    }

@@ -23,13 +23,13 @@ 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 }
    }
 }
@@ -98,12 +98,13 @@ class PtIfElse(position: Position) : PtNode(position) {
        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 }
@@ -111,12 +112,6 @@ 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
@@ -153,7 +148,11 @@ 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) {
@@ -68,9 +68,10 @@ 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),
@@ -78,36 +79,58 @@ val BuiltinFunctions: Map<String, FSignature> = mapOf(
    "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),
-    "prog8_lib_stringcompare"       to FSignature(true, listOf(FParam("str1", arrayOf(DataType.STR)), FParam("str2", arrayOf(DataType.STR))), DataType.BYTE),
-    "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),
+    "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),
-    "divmod"    to FSignature(false, listOf(FParam("number", arrayOf(DataType.UBYTE)), FParam("divident", arrayOf(DataType.UBYTE)), FParam("division", arrayOf(DataType.UBYTE)), FParam("remainder", arrayOf(DataType.UBYTE))), null),
-    "divmodw"   to FSignature(false, listOf(FParam("number", arrayOf(DataType.UWORD)), FParam("divident", arrayOf(DataType.UWORD)), FParam("division", arrayOf(DataType.UWORD)), FParam("remainder", arrayOf(DataType.UWORD))), null),
-    "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("number", arrayOf(DataType.UBYTE, DataType.UWORD)), FParam("divident", arrayOf(DataType.UBYTE, DataType.UWORD)), FParam("division", arrayOf(DataType.UBYTE, DataType.UWORD)), FParam("remainder", arrayOf(DataType.UBYTE, DataType.UWORD))), null),
+    "divmod__ubyte"    to FSignature(false, listOf(FParam("number", arrayOf(DataType.UBYTE)), FParam("divident", arrayOf(DataType.UBYTE)), FParam("division", arrayOf(DataType.UBYTE)), FParam("remainder", arrayOf(DataType.UBYTE))), null),
+    "divmod__uword"    to FSignature(false, listOf(FParam("number", arrayOf(DataType.UWORD)), FParam("divident", arrayOf(DataType.UWORD)), FParam("division", arrayOf(DataType.UWORD)), FParam("remainder", arrayOf(DataType.UWORD))), null),
+    "any"       to FSignature(true, listOf(FParam("values", ArrayDatatypes)), DataType.BOOL),
+    "all"       to FSignature(true, listOf(FParam("values", ArrayDatatypes)), DataType.BOOL),
    "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", "sort", "reverse")
@@ -8,24 +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 experimentalCodegen: Boolean = false,
-                         var varsHigh: Boolean = false,
-                         var useNewExprCode: 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 strictBool: Boolean = true,
+                         var breakpointCpuInstruction: String? = null,
                         var outputDir: Path = Path(""),
                         var symbolDefs: Map<String, String> = emptyMap()
 ) {
    init {
        compTarget.machine.initializeMemoryAreas(this)
    }
+
+    companion object {
+        val AllZeropageAllowed: List<UIntRange> = listOf(0u..255u)
+    }
 }
@@ -58,6 +58,7 @@ 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
@@ -74,6 +79,13 @@ enum class RegisterOrPair {

    companion object {
        val names by lazy { values().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) {
@@ -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 {
@@ -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
@@ -29,11 +29,4 @@ interface IMachineDefinition {
    fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String>
    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" }
-    }
-
 }
@@ -9,6 +9,8 @@ enum class Encoding(val prefix: String) {
 }

 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")
@@ -144,7 +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) {
@@ -1,6 +1,6 @@
 package prog8.code.core

-import prog8.code.core.SourceCode.Companion.libraryFilePrefix
+import prog8.code.core.SourceCode.Companion.LIBRARYFILEPREFIX
 import java.nio.file.InvalidPathException
 import kotlin.io.path.Path
 import kotlin.io.path.absolute
@@ -10,7 +10,7 @@ data class Position(val file: String, val line: Int, val startCol: Int, val endC
    fun toClickableStr(): String {
        if(this===DUMMY)
            return ""
-        if(file.startsWith(libraryFilePrefix))
+        if(file.startsWith(LIBRARYFILEPREFIX))
            return "$file:$line:$startCol:"
        return try {
            val path = Path(file).absolute().normalize().toString()
@@ -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 +1,130 @@
+package prog8.code.optimize
+
+import prog8.code.ast.*
+import prog8.code.core.*
+
+
+fun optimizeIntermediateAst(program: PtProgram, options: CompilationOptions, errors: IErrorReporter) {
+    if (!options.optimize)
+        return
+    while(errors.noErrors() && optimizeCommonSubExpressions(program, errors)>0) {
+        // keep rolling
+    }
+}
+
+
+private fun walkAst(root: PtNode, act: (node: PtNode, depth: Int) -> Boolean) {
+    fun recurse(node: PtNode, depth: Int) {
+        if(act(node, depth))
+            node.children.forEach { recurse(it, depth+1) }
+    }
+    recurse(root, 0)
+}
+
+
+private var tempVarCounter = 0
+
+private fun optimizeCommonSubExpressions(program: PtProgram, errors: IErrorReporter): Int {
+
+    fun extractableSubExpr(expr: PtExpression): Boolean {
+        val result = if(expr is PtBinaryExpression)
+            expr.type !in ByteDatatypes ||
+                    !expr.left.isSimple() ||
+                    !expr.right.isSimple() ||
+                    (expr.operator !in LogicalOperators && expr.operator !in BitwiseOperators)
+        else if (expr is PtArrayIndexer && expr.type !in ByteDatatypes)
+            true
+        else
+            !expr.isSimple()
+        return result
+    }
+
+    // for each Binaryexpression, recurse to find a common subexpression pair therein.
+    val commons = mutableMapOf<PtBinaryExpression, Pair<PtExpression, PtExpression>>()
+    walkAst(program) { node: PtNode, depth: Int ->
+        if(node is PtBinaryExpression) {
+            val subExpressions = mutableListOf<PtExpression>()
+            walkAst(node.left) { subNode: PtNode, subDepth: Int ->
+                if (subNode is PtExpression) {
+                    if(extractableSubExpr(subNode)) subExpressions.add(subNode)
+                    true
+                } else false
+            }
+            walkAst(node.right) { subNode: PtNode, subDepth: Int ->
+                if (subNode is PtExpression) {
+                    if(extractableSubExpr(subNode)) subExpressions.add(subNode)
+                    true
+                } else false
+            }
+
+            outer@for (first in subExpressions) {
+                for (second in subExpressions) {
+                    if (first!==second && first isSameAs second) {
+                        commons[node] = first to second
+                        break@outer     // do only 1 replacement at a time per binaryexpression
+                    }
+                }
+            }
+            false
+        } else true
+    }
+
+    // replace common subexpressions by a temp variable that is assigned only once.
+    // TODO: check for commonalities across multiple separate expressions in the current scope, not only inside a single line
+    commons.forEach { binexpr, (occurrence1, occurrence2) ->
+        val (stmtContainer, stmt) = findContainingStatements(binexpr)
+        val occurrence1idx = occurrence1.parent.children.indexOf(occurrence1)
+        val occurrence2idx = occurrence2.parent.children.indexOf(occurrence2)
+        val containerScopedName = findScopeName(stmtContainer)
+        tempVarCounter++
+        val tempvarName = "prog8_subexprvar_$tempVarCounter"
+        // TODO: some tempvars could be reused, if they are from different lines
+
+        val datatype = occurrence1.type
+        val singleReplacement1 = PtIdentifier("$containerScopedName.$tempvarName", datatype, occurrence1.position)
+        val singleReplacement2 = PtIdentifier("$containerScopedName.$tempvarName", datatype, occurrence2.position)
+        occurrence1.parent.children[occurrence1idx] = singleReplacement1
+        singleReplacement1.parent = occurrence1.parent
+        occurrence2.parent.children[occurrence2idx] = singleReplacement2
+        singleReplacement2.parent = occurrence2.parent
+
+        val tempassign = PtAssignment(binexpr.position).also { assign ->
+            assign.add(PtAssignTarget(binexpr.position).also { tgt->
+                tgt.add(PtIdentifier("$containerScopedName.$tempvarName", datatype, binexpr.position))
+            })
+            assign.add(occurrence1)
+            occurrence1.parent = assign
+        }
+        stmtContainer.children.add(stmtContainer.children.indexOf(stmt), tempassign)
+        tempassign.parent = stmtContainer
+
+        val tempvar = PtVariable(tempvarName, datatype, ZeropageWish.NOT_IN_ZEROPAGE, null, null, binexpr.position)
+        stmtContainer.add(0, tempvar)
+        tempvar.parent = stmtContainer
+
+        // errors.info("common subexpressions replaced by a tempvar, maybe simplify the expression manually", binexpr.position)
+    }
+
+    return commons.size
+}
+
+
+internal fun findScopeName(node: PtNode): String {
+    var parent=node
+    while(parent !is PtNamedNode)
+        parent = parent.parent
+    return parent.scopedName
+}
+
+
+internal fun findContainingStatements(node: PtNode): Pair<PtNode, PtNode> {      // returns (parentstatementcontainer, childstatement)
+    var parent = node.parent
+    var child = node
+    while(true) {
+        if(parent is IPtStatementContainer) {
+            return parent to child
+        }
+        child=parent
+        parent=parent.parent
+    }
+}
@@ -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 {
@@ -11,7 +11,6 @@ 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 {
@@ -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 {
@@ -10,6 +10,8 @@ import prog8.code.target.cbm.PetsciiEncoding


 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)
@@ -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
 }
@@ -13,12 +13,10 @@ 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
@@ -48,6 +48,7 @@ class AtariZeropage(options: CompilationOptions) : Zeropage(options) {
        free.addAll(distinctFree)

        removeReservedFromFreePool()
+        retainAllowed()
    }

    override fun allocateCx16VirtualRegisters() {
@@ -15,12 +15,10 @@ 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
@@ -69,6 +69,7 @@ class C128Zeropage(options: CompilationOptions) : Zeropage(options) {
        free.addAll(distinctFree)

        removeReservedFromFreePool()
+        retainAllowed()
    }

    override fun allocateCx16VirtualRegisters() {
@@ -16,12 +16,10 @@ 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
@@ -62,7 +60,7 @@ class C64MachineDefinition: IMachineDefinition {

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

 }
@@ -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
@@ -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
 }
@@ -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}'")
                }
            }
        }
@@ -15,12 +15,10 @@ 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
@@ -40,7 +38,7 @@ class CX16MachineDefinition: IMachineDefinition {
        when(selectedEmulator) {
            1 -> {
                emulator = "x16emu"
-                extraArgs = emptyList()
+                extraArgs = listOf("-debug")
            }
            2 -> {
                emulator = "box16"
@@ -53,7 +51,7 @@ 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()
@@ -64,7 +62,7 @@ class CX16MachineDefinition: IMachineDefinition {

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

 }
@@ -40,7 +40,6 @@ 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 distinctFree = free.distinct()
@@ -48,8 +47,8 @@ class CX16Zeropage(options: CompilationOptions) : Zeropage(options) {
            free.addAll(distinctFree)

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

@@ -0,0 +1,57 @@
+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 importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
+        return if (compilerOptions.launcher == CbmPrgLauncherType.BASIC || compilerOptions.output == OutputType.PRG)
+            listOf("syslib")
+        else
+            emptyList()
+    }
+
+    override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
+        if(selectedEmulator!=1) {
+            System.err.println("The 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")
+    }
+}
@@ -12,20 +12,20 @@ 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(", ")
    }
@@ -1,9 +1,7 @@
-
 plugins {
    id 'java'
    id 'application'
    id "org.jetbrains.kotlin.jvm"
-    id "io.kotest" version "0.3.9"
 }

 java {
@@ -28,18 +26,20 @@ 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:1.1.20"

-    testImplementation 'io.kotest:kotest-runner-junit5-jvm:5.5.5'
+    testImplementation 'io.kotest:kotest-runner-junit5-jvm:5.8.0'
+    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 {
@@ -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 +29,21 @@ 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)
@@ -58,7 +58,7 @@ 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)
@@ -75,61 +75,48 @@ 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> {
@@ -319,7 +306,7 @@ private fun optimizeSameAssignments(
    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:
@@ -356,31 +343,57 @@ 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()

+        // 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 =
@@ -419,15 +432,21 @@ 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
@@ -458,7 +477,7 @@ 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) {
@@ -475,14 +494,17 @@ 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) {
@@ -514,6 +536,109 @@ 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  $label")
+                mods += Modification(lines[3].index, true, null)
+            }
+        }
    }
    return mods
 }
+
+private fun optimizeUselessPushPopStack(linesByFour: Sequence<List<IndexedValue<String>>>): List<Modification> {
+    val mods = mutableListOf<Modification>()
+
+    fun optimize(register: Char, lines: List<IndexedValue<String>>) {
+        if(lines[0].value.trimStart().startsWith("ph$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)
+    }
+    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) }
-}
@@ -1,14 +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 prog8.code.target.C64Target
-import java.io.File
 import java.nio.file.Path
-import kotlin.io.path.Path
-import kotlin.io.path.isRegularFile


 internal class AssemblyProgram(
@@ -28,15 +22,20 @@ internal class AssemblyProgram(
        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",
+                    "-Wall", // "-Wno-strict-bool", "-Werror",
                    "--dump-labels", "--vice-labels", "--labels=$viceMonListFile", "--no-monitor"
                )

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

@@ -65,10 +64,15 @@ 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")

@@ -130,18 +134,3 @@ 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)
-    }
-}
@@ -1,929 +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 -> translateContainmentCheck(expression)
-            is PtArray, is PtString -> throw AssemblyError("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 translateContainmentCheck(check: PtContainmentCheck) {
-        asmgen.assignExpressionToRegister(check, RegisterOrPair.A)
-        asmgen.out("  sta  P8ESTACK_LO,x |  dex")
-    }
-
-    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) {
-        require(!asmgen.options.useNewExprCode)
-
-        // Uses evalstack to evaluate the given expression.  THIS IS SLOW AND SHOULD BE AVOIDED!
-        if(translateSomewhatOptimized(expr.left, expr.operator, expr.right))
-            return
-
-        val leftDt = expr.left.type
-        val rightDt = expr.right.type
-
-        // compare with zero
-        if(expr.operator 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==DataType.STR && rightDt==DataType.STR && expr.operator in ComparisonOperators)
-            return translateCompareStrings(expr.left, expr.operator, expr.right)
-
-        if((leftDt in ByteDatatypes && rightDt !in ByteDatatypes)
-                || (leftDt in WordDatatypes && rightDt !in WordDatatypes))
-            throw AssemblyError("binary operator ${expr.operator} left/right dt not identical")
-
-        // 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 translateSomewhatOptimized(left: PtExpression, operator: String, right: PtExpression): Boolean {
-        val leftDt = left.type
-        val rightDt = right.type
-        when(operator) {
-            "+" -> {
-                if(leftDt in IntegerDatatypes && rightDt in IntegerDatatypes) {
-                    val leftVal = left.asConstInteger()
-                    val rightVal = right.asConstInteger()
-                    if (leftVal!=null && leftVal in -4..4) {
-                        translateExpressionInternal(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 true
-                    }
-                    else if (rightVal!=null && rightVal in -4..4)
-                    {
-                        translateExpressionInternal(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 true
-                    }
-                }
-            }
-            "-" -> {
-                if(leftDt in IntegerDatatypes && rightDt in IntegerDatatypes) {
-                    val rightVal = right.asConstInteger()
-                    if (rightVal!=null && rightVal in -4..4)
-                    {
-                        translateExpressionInternal(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 true
-                    }
-                }
-            }
-            ">>" -> {
-                val amount = right.asConstInteger()
-                if(amount!=null) {
-                    translateExpressionInternal(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 true
-                            }
-                            var amountLeft = amount
-                            while (amountLeft >= 7) {
-                                asmgen.out(" jsr  math.shift_right_uw_7")
-                                amountLeft -= 7
-                            }
-                            if (amountLeft in 0..2)
-                                repeat(amountLeft) { asmgen.out(" lsr  P8ESTACK_HI+1,x |  ror  P8ESTACK_LO+1,x") }
-                            else
-                                asmgen.out(" jsr  math.shift_right_uw_$amountLeft")
-                        }
-                        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 true
-                            }
-                            var amountLeft = amount
-                            while (amountLeft >= 7) {
-                                asmgen.out(" jsr  math.shift_right_w_7")
-                                amountLeft -= 7
-                            }
-                            if (amountLeft in 0..2)
-                                repeat(amountLeft) { 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_$amountLeft")
-                        }
-                        else -> throw AssemblyError("weird type")
-                    }
-                    return true
-                }
-            }
-            "<<" -> {
-                val amount = right.asConstInteger()
-                if(amount!=null) {
-                    translateExpressionInternal(left)
-                    if (leftDt in ByteDatatypes) {
-                        if (amount <= 2)
-                            repeat(amount) { asmgen.out("  asl  P8ESTACK_LO+1,x") }
-                        else {
-                            asmgen.out("  lda  P8ESTACK_LO+1,x")
-                            repeat(amount) { asmgen.out("  asl  a") }
-                            asmgen.out("  sta  P8ESTACK_LO+1,x")
-                        }
-                    } else {
-                        var amountLeft = amount
-                        while (amountLeft >= 7) {
-                            asmgen.out(" jsr  math.shift_left_w_7")
-                            amountLeft -= 7
-                        }
-                        if (amountLeft in 0..2)
-                            repeat(amountLeft) { asmgen.out("  asl  P8ESTACK_LO+1,x |  rol  P8ESTACK_HI+1,x") }
-                        else
-                            asmgen.out(" jsr  math.shift_left_w_$amountLeft")
-                    }
-                    return true
-                }
-            }
-            "*" -> {
-                if(leftDt in IntegerDatatypes && rightDt in IntegerDatatypes) {
-                    val leftVar = left as? PtIdentifier
-                    val rightVar = right as? PtIdentifier
-                    if(leftVar!=null && rightVar!=null && leftVar==rightVar) {
-                        translateSquared(leftVar, leftDt)
-                        return true
-                    }
-                }
-
-                val value = right as? PtNumber
-                if(value!=null) {
-                    if(rightDt in IntegerDatatypes) {
-                        val amount = value.number.toInt()
-                        if(amount==2) {
-                            // optimize x*2 common case
-                            translateExpressionInternal(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 true
-                        }
-                        when(rightDt) {
-                            DataType.UBYTE -> {
-                                if(amount in asmgen.optimizedByteMultiplications) {
-                                    translateExpressionInternal(left)
-                                    asmgen.out(" jsr  math.stack_mul_byte_$amount")
-                                    return true
-                                }
-                            }
-                            DataType.BYTE -> {
-                                if(amount in asmgen.optimizedByteMultiplications) {
-                                    translateExpressionInternal(left)
-                                    asmgen.out(" jsr  math.stack_mul_byte_$amount")
-                                    return true
-                                }
-                                if(amount.absoluteValue in asmgen.optimizedByteMultiplications) {
-                                    translateExpressionInternal(left)
-                                    asmgen.out(" jsr  prog8_lib.neg_b |  jsr  math.stack_mul_byte_${amount.absoluteValue}")
-                                    return true
-                                }
-                            }
-                            DataType.UWORD -> {
-                                if(amount in asmgen.optimizedWordMultiplications) {
-                                    translateExpressionInternal(left)
-                                    asmgen.out(" jsr  math.stack_mul_word_$amount")
-                                    return true
-                                }
-                            }
-                            DataType.WORD -> {
-                                if(amount in asmgen.optimizedWordMultiplications) {
-                                    translateExpressionInternal(left)
-                                    asmgen.out(" jsr  math.stack_mul_word_$amount")
-                                    return true
-                                }
-                                if(amount.absoluteValue in asmgen.optimizedWordMultiplications) {
-                                    translateExpressionInternal(left)
-                                    asmgen.out(" jsr  prog8_lib.neg_w |  jsr  math.stack_mul_word_${amount.absoluteValue}")
-                                    return true
-                                }
-                            }
-                            else -> {}
-                        }
-                    }
-                }
-            }
-            "/" -> {
-                if(leftDt in IntegerDatatypes && rightDt in IntegerDatatypes) {
-                    val rightVal = right.asConstInteger()
-                    if(rightVal!=null && rightVal==2) {
-                        translateExpressionInternal(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 true
-                    }
-                }
-            }
-        }
-
-        return false
-    }
-
-    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.lessequalzero_sb")
-                    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)
-        asmgen.assignExpressionToVariable(s2, "prog8_lib.strcmp_expression._arg_s2", DataType.UWORD)
-        asmgen.out(" jsr  prog8_lib.strcmp_expression")    // result  of compare is in A
-        compareStringsProcessResultInA(operator)
-    }
-
-    private fun compareStringsProcessResultInA(operator: String) {
-        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
@@ -51,7 +56,35 @@ internal class ForLoopsAsmGen(private val program: PtProgram,
                    // loop over byte range via loopvar
                    val varname = asmgen.asmVariableName(stmt.variable)
                    asmgen.assignExpressionToVariable(range.from, varname, ArrayToElementTypes.getValue(iterableDt))
-                    asmgen.assignExpressionToVariable(range.to, "$modifiedLabel+1", ArrayToElementTypes.getValue(iterableDt))
+                    asmgen.assignExpressionToRegister(range.to, RegisterOrPair.A, false)
+                    // pre-check for end already reached
+                    if(iterableDt==DataType.ARRAY_B) {
+                        asmgen.out("  sta  $modifiedLabel+1")
+                        if(stepsize<0)
+                            asmgen.out("""
+                                clc
+                                sbc  $varname
+                                bvc  +
+                                eor  #${'$'}80
+                               bpl  $endLabel""")
+                        else
+                            asmgen.out("""
+                                sec
+                                sbc  $varname
+                                bvc  +
+                                eor  #${'$'}80
+                               bmi  $endLabel""")
+                    } else {
+                        if(stepsize<0)
+                            asmgen.out("""
+                                cmp  $varname
+                                beq  +
+                                bcs  $endLabel
+""")
+                        else
+                            asmgen.out("  cmp  $varname  |  bcc  $endLabel")
+                        asmgen.out("  sta  $modifiedLabel+1")
+                    }
                    asmgen.out(loopLabel)
                    asmgen.translate(stmt.statements)
                    asmgen.out("""
@@ -69,7 +102,35 @@ $modifiedLabel          cmp  #0         ; modified
                    // loop over byte range via loopvar
                    val varname = asmgen.asmVariableName(stmt.variable)
                    asmgen.assignExpressionToVariable(range.from, varname, ArrayToElementTypes.getValue(iterableDt))
-                    asmgen.assignExpressionToVariable(range.to, "$modifiedLabel+1", ArrayToElementTypes.getValue(iterableDt))
+                    asmgen.assignExpressionToRegister(range.to, RegisterOrPair.A, false)
+                    // pre-check for end already reached
+                    if(iterableDt==DataType.ARRAY_B) {
+                        asmgen.out("  sta  $modifiedLabel+1")
+                        if(stepsize<0)
+                            asmgen.out("""
+                                clc
+                                sbc  $varname
+                                bvc  +
+                                eor  #${'$'}80
+                               bpl  $endLabel""")
+                        else
+                            asmgen.out("""
+                                sec
+                                sbc  $varname
+                                bvc  +
+                                eor  #${'$'}80
+                               bmi  $endLabel""")
+                    } else {
+                        if(stepsize<0)
+                            asmgen.out("""
+                                cmp  $varname
+                                beq  +
+                                bcs  $endLabel
+""")
+                        else
+                            asmgen.out("  cmp  $varname  |  bcc  $endLabel")
+                        asmgen.out("  sta  $modifiedLabel+1")
+                    }
                    asmgen.out(loopLabel)
                    asmgen.translate(stmt.statements)
                    if(stepsize>0) {
@@ -100,8 +161,9 @@ $modifiedLabel              cmp  #0     ; modified

                    stepsize == 1 || stepsize == -1 -> {
                        val varname = asmgen.asmVariableName(stmt.variable)
-                        assignLoopvar(stmt, range)
+                        assignLoopvarWord(stmt, range)
                        asmgen.assignExpressionToRegister(range.to, RegisterOrPair.AY)
+                        precheckFromToWord(iterableDt, stepsize, varname, endLabel)
                        asmgen.out("""
                            sty  $modifiedLabel+1
                            sta  $modifiedLabel2+1
@@ -134,8 +196,9 @@ $modifiedLabel2 cmp  #0    ; modified

                        // (u)words, step >= 2
                        val varname = asmgen.asmVariableName(stmt.variable)
-                        assignLoopvar(stmt, range)
+                        assignLoopvarWord(stmt, range)
                        asmgen.assignExpressionToRegister(range.to, RegisterOrPair.AY)
+                        precheckFromToWord(iterableDt, stepsize, varname, endLabel)
                        asmgen.out("""
                            sty  $modifiedLabel+1
                            sta  $modifiedLabel2+1
@@ -182,41 +245,25 @@ $endLabel""")

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

-                        if(iterableDt==DataType.ARRAY_UW) {
                            asmgen.out("""
                lda  $varname
                sec
                sbc  #<${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
@@ -224,7 +271,6 @@ $modifiedLabel  sbc  #0    ; modified
                eor  #$80
 +               bpl  $loopLabel                
 $endLabel""")
-                        }
                    }
                }
            }
@@ -234,17 +280,66 @@ $endLabel""")
        asmgen.loopEndLabels.pop()
    }

+    private fun precheckFromToWord(iterableDt: DataType, stepsize: Int, fromVar: String, endLabel: String) {
+        // pre-check for end already reached.
+        // 'to' is in AY, do NOT clobber this!
+        if(iterableDt==DataType.ARRAY_W) {
+            if(stepsize<0)
+                asmgen.out("""
+                    sta  P8ZP_SCRATCH_W2        ; to
+                    sty  P8ZP_SCRATCH_W2+1      ; to
+                    lda  $fromVar
+	                cmp  P8ZP_SCRATCH_W2
+                    lda  $fromVar+1
+	                sbc  P8ZP_SCRATCH_W2+1
+	                bvc  +
+	                eor  #${'$'}80
+           		bmi  $endLabel
+                    lda  P8ZP_SCRATCH_W2
+                    ldy  P8ZP_SCRATCH_W2+1""")
+            else
+                asmgen.out("""
+                    sta  P8ZP_SCRATCH_REG
+	                cmp  $fromVar
+	                tya
+	                sbc  $fromVar+1
+	                bvc  +
+	                eor  #${'$'}80
+           		bmi  $endLabel
+                    lda  P8ZP_SCRATCH_REG""")
+        } else {
+            if(stepsize<0)
+                asmgen.out("""
+                    cpy  $fromVar+1
+                    beq  +
+                    bcc  ++
+                    bcs  $endLabel
+                   cmp  $fromVar
+                    bcc  +
+                    beq  +
+                    bne  $endLabel
+""")
+            else
+                asmgen.out("""
+                	cpy  $fromVar+1
+	                bcc  $endLabel
+	                bne  +
+	                cmp  $fromVar
+	                bcc  $endLabel
+""")
+        }
+    }
+
    private fun translateForOverIterableVar(stmt: PtForLoop, iterableDt: DataType, ident: PtIdentifier) {
        val loopLabel = asmgen.makeLabel("for_loop")
        val endLabel = asmgen.makeLabel("for_end")
        asmgen.loopEndLabels.push(endLabel)
        val iterableName = asmgen.asmVariableName(ident)
        val 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(symbol) {
+            is StStaticVariable -> symbol.length!!
+            is StMemVar -> symbol.length!!
+            else -> 0
        }
        when(iterableDt) {
            DataType.STR -> {
@@ -264,7 +359,7 @@ $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 +367,7 @@ $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 +382,11 @@ $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 +395,7 @@ $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 +406,7 @@ $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 +423,49 @@ $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 {
@@ -590,7 +723,7 @@ $loopLabel""")
        asmgen.loopEndLabels.pop()
    }

-    private fun assignLoopvar(stmt: PtForLoop, range: PtRange) =
+    private fun assignLoopvarWord(stmt: PtForLoop, range: PtRange) =
        asmgen.assignExpressionToVariable(
            range.from,
            asmgen.asmVariableName(stmt.variable),
@@ -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 PtMachineRegister -> false
+            is PtMemoryByte -> return usesOtherRegistersWhileEvaluating(arg.address)
+            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, false)
+                        if(usedY()) asmgen.saveRegisterStack(CpuRegister.Y, false)
+                        if(usedA()) asmgen.saveRegisterStack(CpuRegister.A, false)
+                        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)
+                }
+            }
        }
    }

@@ -144,7 +135,7 @@ internal class FunctionCallAsmGen(private val program: PtProgram, private val as
        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
@@ -183,15 +178,11 @@ 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
@@ -224,12 +215,15 @@ internal class FunctionCallAsmGen(private val program: PtProgram, private val as
                }
                asmgen.translateNormalAssignment(AsmAssignment(src, target, program.memsizer, Position.DUMMY), scope)
            }
+            return RegisterOrStatusflag(register, null)
        }
    }

    private fun isArgumentTypeCompatible(argType: DataType, paramType: DataType): Boolean {
        if(argType isAssignableTo paramType)
            return true
+        if(argType==DataType.BOOL && paramType==DataType.BOOL)
+            return true
        if(argType in ByteDatatypes && paramType in ByteDatatypes)
            return true
        if(argType in WordDatatypes && paramType in WordDatatypes)
@@ -245,3 +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")
            }
        }

@@ -134,29 +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 |  lda  #0 |  sta ${"$"}ff00")
-                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")
        }
    }

@@ -173,47 +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)
@@ -236,7 +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> =
@@ -269,16 +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 {
@@ -301,7 +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 {
@@ -311,7 +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)

@@ -331,7 +397,7 @@ 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)) {
@@ -339,7 +405,7 @@ internal class ProgramAndVarsGen(
            if(sub.parameters.size==1) {
                val dt = sub.parameters[0].type
                val target = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, dt, sub, sub.parameters[0].position, variableAsmName = sub.parameters[0].name)
-                if(dt in ByteDatatypes)
+                if(dt in ByteDatatypesWithBoolean)
                    asmgen.assignRegister(RegisterOrPair.A, target)
                else
                    asmgen.assignRegister(RegisterOrPair.AY, target)
@@ -369,12 +435,6 @@ internal class ProgramAndVarsGen(
                else -> throw AssemblyError("weird dt for extravar $dt")
            }
        }
-        if(asmGenInfo.usedRegsaveA)      // will probably never occur
-            asmgen.out("prog8_regsaveA     .byte  ?")
-        if(asmGenInfo.usedRegsaveX)
-            asmgen.out("prog8_regsaveX     .byte  ?")
-        if(asmGenInfo.usedRegsaveY)
-            asmgen.out("prog8_regsaveY     .byte  ?")
        if(asmGenInfo.usedFloatEvalResultVar1)
            asmgen.out("$subroutineFloatEvalResultVar1    .fill  ${options.compTarget.machine.FLOAT_MEM_SIZE}")
        if(asmGenInfo.usedFloatEvalResultVar2)
@@ -434,12 +494,12 @@ internal class ProgramAndVarsGen(
                asmgen.out("""
                    lda  #<${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""")
@@ -458,7 +518,6 @@ internal class ProgramAndVarsGen(
        }

        asmgen.out("""+        
-                    ldx  #127       ; init estack ptr (half page)
                    clv
                    clc""")
    }
@@ -480,8 +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
@@ -492,8 +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
@@ -504,7 +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}")
+            }
        }
    }

@@ -538,11 +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")
@@ -563,6 +635,7 @@ internal class ProgramAndVarsGen(
            } else 0

        when (variable.dt) {
+            DataType.BOOL -> TODO("bool var to asm")
            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()}")
@@ -587,7 +660,7 @@ 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  ${data.joinToString()}")
@@ -627,6 +700,18 @@ internal class ProgramAndVarsGen(
                        asmgen.out("  .sint  " + chunk.joinToString())
                }
            }
+            DataType.ARRAY_UW_SPLIT -> {
+                val data = makeArrayFillDataUnsigned(dt, value, orNumberOfZeros)
+                asmgen.out("_array_$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_$varname")
+            }
            DataType.ARRAY_F -> {
                val array = value ?: zeroFilledArray(orNumberOfZeros!!)
                val floatFills = array.map {
@@ -643,7 +728,7 @@ internal class ProgramAndVarsGen(
    private fun zeroFilledArray(numElts: Int): StArray {
        val values = mutableListOf<StArrayElement>()
        repeat(numElts) {
-            values.add(StArrayElement(0.0, null))
+            values.add(StArrayElement(0.0, null, null))
        }
        return values
    }
@@ -680,13 +765,23 @@ internal class ProgramAndVarsGen(
    private fun makeArrayFillDataUnsigned(dt: DataType, value: StArray?, orNumberOfZeros: Int?): List<String> {
        val array = value ?: zeroFilledArray(orNumberOfZeros!!)
        return when (dt) {
+            DataType.ARRAY_BOOL ->
+                // byte array can never contain pointer-to types, so treat values as all integers
+                array.map {
+                    if(it.boolean!=null)
+                        if(it.boolean==true) "1" else "0"
+                    else {
+                        val number = it.number!!
+                        if(number==0.0) "0" else "1"
+                    }
+                }
            DataType.ARRAY_UB ->
                // byte array can never contain pointer-to types, so treat values as all integers
                array.map {
                    val number = it.number!!.toInt()
                    "$"+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')
                }
@@ -718,11 +813,11 @@ 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)
@@ -91,7 +91,7 @@ internal class VariableAllocator(private val symboltable: SymbolTable,
            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 {
@@ -0,0 +1,253 @@
+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"
+                }
+                return assignWordBinExpr(expr)
+            }
+            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 assignWordBinExpr(expr: PtBinaryExpression): Boolean {
+        when(expr.operator) {
+            "+" -> TODO("word + at ${expr.position}")
+            "-" -> TODO("word - at ${expr.position}")
+            "*" -> TODO("word * at ${expr.position}")
+            "/" -> TODO("word / at ${expr.position}")
+            "<<" -> TODO("word << at ${expr.position}")
+            ">>" -> TODO("word >> at ${expr.position}")
+            "%" -> TODO("word % at ${expr.position}")
+            "and" -> TODO("word logical and (with optional shortcircuit) ${expr.position}")
+            "or" -> TODO("word logical or (with optional shortcircuit) ${expr.position}")
+            "&" -> TODO("word and at ${expr.position}")
+            "|" -> TODO("word or at ${expr.position}")
+            "^", "xor" -> TODO("word xor at ${expr.position}")
+            "==" -> TODO("word == at ${expr.position}")
+            "!=" -> TODO("word != at ${expr.position}")
+            "<" -> TODO("word < at ${expr.position}")
+            "<=" -> TODO("word <= at ${expr.position}")
+            ">" -> TODO("word > at ${expr.position}")
+            ">=" -> TODO("word >= at ${expr.position}")
+            else -> return false
+        }
+    }
+
+    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
 }

@@ -45,8 +44,8 @@ internal class AsmAssignTarget(val kind: TargetStorageKind,
    }

    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 {
@@ -115,12 +114,12 @@ internal class AsmAssignTarget(val kind: TargetStorageKind,
                left is PtIdentifier && left.name==scopedName
            }
            TargetStorageKind.ARRAY -> {
-                left is PtArrayIndexer && left isSameAs array!!
+                left is PtArrayIndexer && left isSameAs array!! && left.splitWords==array.splitWords
            }
            TargetStorageKind.MEMORY -> {
                left isSameAs memory!!
            }
-            TargetStorageKind.REGISTER, TargetStorageKind.STACK -> {
+            TargetStorageKind.REGISTER -> {
                false
            }
        }
@@ -135,6 +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
 )
 {
@@ -149,6 +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")
@@ -178,8 +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")

@@ -196,7 +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()
    }
@@ -27,11 +29,11 @@ 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) {
        val text = "${position.toClickableStr()} $msg"
@@ -45,13 +47,25 @@ internal class ErrorReporterForTests(private val throwExceptionAtReportIfErrors:
            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()
        }
@@ -60,5 +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))
@@ -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
+            }
+        }
+    }
 })

@@ -29,17 +29,17 @@ 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:1.1.20"

 }

 sourceSets {
    main {
        java {
-            srcDirs = ["${project.projectDir}/src"]
+            srcDir "${project.projectDir}/src"
        }
        resources {
-            srcDirs = ["${project.projectDir}/res"]
+            srcDir "${project.projectDir}/res"
        }
    }
 }
@@ -15,7 +15,7 @@ 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:
@@ -26,6 +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
+    }
+
+}
@@ -28,18 +28,21 @@ 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:1.1.20"
+
+    testImplementation 'io.kotest:kotest-runner-junit5-jvm:5.8.0'
+    testImplementation 'org.junit.jupiter:junit-jupiter:5.9.2'
+    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'

-    testImplementation 'io.kotest:kotest-runner-junit5-jvm:5.5.5'
 }

 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="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="michael.bull.kotlin.result.jvm" level="project" />
  </component>
 </module>
@@ -1,20 +1,42 @@
 package prog8.codegen.intermediate

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

-internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
-    fun optimizeOnlyJoinChunks() {
-        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
    }

-    fun optimize() {
-        irprog.blocks.asSequence().flatMap { it.children.filterIsInstance<IRSubroutine>() }.forEach { sub ->
+    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
@@ -23,20 +45,39 @@ 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
+                        // TODO other optimizations
                    } while (changed)
                }
            }
            removeEmptyChunks(sub)
        }

-        irprog.linkChunks() // re-link
+        // TODO also do register optimization step here at the end?
+
+        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) {
@@ -46,7 +87,7 @@ 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: merge both 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.
@@ -55,6 +96,7 @@ 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()) {
@@ -68,10 +110,18 @@ 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: merge 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!!
+                                    }
+                                }
                            }
                        }
                    }
@@ -81,10 +131,32 @@ 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) {
@@ -93,7 +165,7 @@ 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) {
@@ -110,12 +182,41 @@ 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
+            val candidate = sub.chunks[ix]
+            when(candidate) {
+                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
@@ -202,10 +303,45 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
            }

            // replace call + return --> jump
-            if(idx>0 && ins.opcode==Opcode.RETURN) {
-                val previous = chunk.instructions[idx-1]
-                if(previous.opcode==Opcode.CALL || previous.opcode==Opcode.CALLR) {
-                    chunk.instructions[idx-1] = IRInstruction(Opcode.JUMP, address = previous.address, labelSymbol = previous.labelSymbol, branchTarget = previous.branchTarget)
+            // 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
                }
@@ -214,6 +350,20 @@ 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
@@ -283,18 +433,21 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
    }

    private fun removeDoubleLoadsAndStores(chunk: IRCodeChunk, indexedInstructions: List<IndexedValue<IRInstruction>>): Boolean {
+        return false
+
+/*
        var changed = false
        indexedInstructions.forEach { (idx, ins) ->

            // 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
            // ...
        }
        return changed
+*/
    }
 }
@@ -0,0 +1,103 @@
+package prog8.codegen.intermediate
+
+import prog8.intermediate.IRProgram
+
+
+class IRRegisterOptimizer(private val irProg: IRProgram) {
+    fun optimize() {
+        // reuseRegisters()
+    }
+
+/*
+    TODO: this register re-use renumbering isn't going to work like this,
+    because subroutines will be clobbering the registers that the subroutine
+    which is calling them might be using...
+
+
+    private fun reuseRegisters() {
+
+        fun addToUsage(usage: MutableMap<Pair<Int, IRDataType>, MutableSet<IRCodeChunkBase>>,
+                       regnum: Int,
+                       dt: IRDataType,
+                       chunk: IRCodeChunkBase) {
+            val key = regnum to dt
+            val chunks = usage[key] ?: mutableSetOf()
+            chunks.add(chunk)
+            usage[key] = chunks
+        }
+
+        val usage: MutableMap<Pair<Int, IRDataType>, MutableSet<IRCodeChunkBase>> = mutableMapOf()
+
+        irProg.foreachCodeChunk { chunk ->
+            chunk.usedRegisters().regsTypes.forEach { (regNum, types) ->
+                types.forEach { dt ->
+                    addToUsage(usage, regNum, dt, chunk)
+                }
+            }
+        }
+
+        val registerReplacements = usage.asSequence()
+            .filter { it.value.size==1 }
+            .map { it.key to it.value.iterator().next() }
+            .groupBy({ it.second }, {it.first})
+            .asSequence()
+            .associate { (chunk, registers) ->
+                chunk to registers.withIndex().associate { (index, reg) -> reg to 50000+index }
+            }
+
+        registerReplacements.forEach { replaceRegisters(it.key, it.value) }
+    }
+
+    private fun replaceRegisters(chunk: IRCodeChunkBase, replacements: Map<Pair<Int, IRDataType>, Int>) {
+        val (rF, rI) = replacements.asSequence().partition { it.key.second==IRDataType.FLOAT }
+        val replacementsInt = rI.associate { it.key.first to it.value }
+        val replacementsFloat = rF.associate { it.key.first to it.value }
+
+        fun replaceRegs(fcallArgs: FunctionCallArgs?): FunctionCallArgs? {
+            if(fcallArgs==null)
+                return null
+            val args = if(fcallArgs.arguments.isEmpty()) fcallArgs.arguments else {
+                fcallArgs.arguments.map {
+                    FunctionCallArgs.ArgumentSpec(
+                        it.name,
+                        it.address,
+                        FunctionCallArgs.RegSpec(
+                            it.reg.dt,
+                            if(it.reg.dt==IRDataType.FLOAT)
+                                replacementsFloat.getOrDefault(it.reg.registerNum, it.reg.registerNum)
+                            else
+                                replacementsInt.getOrDefault(it.reg.registerNum, it.reg.registerNum),
+                            it.reg.cpuRegister
+                        )
+                    )
+                }
+            }
+            val rt = fcallArgs.returns
+            val returns = if(rt==null) null else {
+                FunctionCallArgs.RegSpec(
+                    rt.dt,
+                    if(rt.dt==IRDataType.FLOAT)
+                        replacementsFloat.getOrDefault(rt.registerNum, rt.registerNum)
+                    else
+                        replacementsInt.getOrDefault(rt.registerNum, rt.registerNum),
+                    rt.cpuRegister
+                )
+            }
+            return FunctionCallArgs(args, returns)
+        }
+
+        fun replaceRegs(instruction: IRInstruction): IRInstruction {
+            val reg1 = replacementsInt.getOrDefault(instruction.reg1, instruction.reg1)
+            val reg2 = replacementsInt.getOrDefault(instruction.reg2, instruction.reg2)
+            val fpReg1 = replacementsFloat.getOrDefault(instruction.fpReg1, instruction.fpReg1)
+            val fpReg2 = replacementsFloat.getOrDefault(instruction.fpReg2, instruction.fpReg2)
+            return instruction.copy(reg1 = reg1, reg2 = reg2, fpReg1 = fpReg1, fpReg2 = fpReg2, fcallArgs = replaceRegs(instruction.fcallArgs))
+        }
+        val newInstructions = chunk.instructions.map {
+            replaceRegs(it)
+        }
+        chunk.instructions.clear()
+        chunk.instructions.addAll(newInstructions)
+    }
+*/
+}
@@ -1,45 +1,21 @@
 package prog8.codegen.intermediate

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


-internal class IRUnusedCodeRemover(
+class IRUnusedCodeRemover(
    private val irprog: IRProgram,
-    private val symbolTable: IRSymbolTable,
    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)
-                    symbolTable.removeTree(sub.label)
-                    numRemoved++
-                }
-            }
-        }
+        var numRemoved = removeUnusedSubroutines() + removeUnusedAsmSubroutines()

        // remove empty blocks
        irprog.blocks.reversed().forEach { block ->
            if(block.isEmpty()) {
                irprog.blocks.remove(block)
-                symbolTable.removeTree(block.label)
+                pruneSymboltable(block.label)
                numRemoved++
            }
        }
@@ -47,9 +23,144 @@ internal class IRUnusedCodeRemover(
        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.label=="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>()
@@ -57,7 +168,13 @@ internal class IRUnusedCodeRemover(
                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!!
                }
@@ -79,29 +196,48 @@ internal class IRUnusedCodeRemover(
    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) }
+}
@@ -16,7 +16,7 @@ class VmCodeGen: ICodeGeneratorBackend {
        symbolTable: SymbolTable,
        options: CompilationOptions,
        errors: IErrorReporter
-    ): IAssemblyProgram? {
+    ): IAssemblyProgram {
        val irCodeGen = IRCodeGen(program, symbolTable, options, errors)
        val irProgram = irCodeGen.generate()
        return VmAssemblyProgram(irProgram.name, irProgram)
@@ -3,7 +3,7 @@ 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
    }
@@ -16,6 +16,8 @@ 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()
    }
@@ -25,11 +27,11 @@ 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) {
        val text = "${position.toClickableStr()} $msg"
@@ -43,13 +45,25 @@ internal class ErrorReporterForTests(private val throwExceptionAtReportIfErrors:
            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()
        }
@@ -58,5 +72,6 @@ internal class ErrorReporterForTests(private val throwExceptionAtReportIfErrors:
    fun clear() {
        errors.clear()
        warnings.clear()
+        infos.clear()
    }
 }
@@ -8,7 +8,7 @@ import prog8.intermediate.*
 class TestIRPeepholeOpt: FunSpec({
    fun makeIRProgram(chunks: List<IRCodeChunkBase>): IRProgram {
        require(chunks.first().label=="main.start")
-        val block = IRBlock("main", null, IRBlock.BlockAlignment.NONE, Position.DUMMY)
+        val block = IRBlock("main", false, IRBlock.Options(), Position.DUMMY)
        val sub = IRSubroutine("main.start", emptyList(), null, Position.DUMMY)
        chunks.forEach { sub += it }
        block += sub
@@ -18,12 +18,13 @@ class TestIRPeepholeOpt: FunSpec({
            CbmPrgLauncherType.NONE,
            ZeropageType.DONTUSE,
            emptyList(),
+            CompilationOptions.AllZeropageAllowed,
            floats = false,
            noSysInit = true,
            compTarget = target,
            loadAddress = target.machine.PROGRAM_LOAD_ADDRESS
        )
-        val prog = IRProgram("test", IRSymbolTable(null), options, target)
+        val prog = IRProgram("test", IRSymbolTable(), options, target)
        prog.addBlock(block)
        prog.linkChunks()
        prog.validate()
@@ -36,7 +37,7 @@ class TestIRPeepholeOpt: FunSpec({
        return makeIRProgram(listOf(chunk))
    }

-    fun IRProgram.chunks(): List<IRCodeChunkBase> = this.blocks.flatMap { it.children.filterIsInstance<IRSubroutine>() }.flatMap { it.chunks }
+    fun IRProgram.chunks(): List<IRCodeChunkBase> = this.allSubs().flatMap { it.chunks }.toList()

    test("remove nops") {
        val irProg = makeIRProgram(listOf(
@@ -46,15 +47,15 @@ class TestIRPeepholeOpt: FunSpec({
        ))
        irProg.chunks().single().instructions.size shouldBe 3
        val opt = IRPeepholeOptimizer(irProg)
-        opt.optimize()
+        opt.optimize(true, ErrorReporterForTests())
        irProg.chunks().single().instructions.size shouldBe 1
    }

    test("remove jmp to label below") {
        val c1 = IRCodeChunk("main.start", null)
-        c1 += IRInstruction(Opcode.JUMP, labelSymbol = "label")  // removed, but chunk stays because of label
+        c1 += IRInstruction(Opcode.JUMP, labelSymbol = "label")
        val c2 = IRCodeChunk("label", null)
-        c2 += IRInstruction(Opcode.JUMP, labelSymbol = "label2") // removed, but chunk stays because of label
+        c2 += IRInstruction(Opcode.JUMP, labelSymbol = "label2")
        c2 += IRInstruction(Opcode.NOP)  // removed
        val c3 = IRCodeChunk("label2", null)
        c3 += IRInstruction(Opcode.JUMP, labelSymbol = "label3")
@@ -65,16 +66,14 @@ class TestIRPeepholeOpt: FunSpec({
        irProg.chunks().size shouldBe 4
        irProg.chunks().flatMap { it.instructions }.size shouldBe 5
        val opt = IRPeepholeOptimizer(irProg)
-        opt.optimize()
-        irProg.chunks().size shouldBe 4
+        opt.optimize(true, ErrorReporterForTests())
+        irProg.chunks().size shouldBe 3
        irProg.chunks()[0].label shouldBe "main.start"
-        irProg.chunks()[1].label shouldBe "label"
-        irProg.chunks()[2].label shouldBe "label2"
-        irProg.chunks()[3].label shouldBe "label3"
+        irProg.chunks()[1].label shouldBe "label2"
+        irProg.chunks()[2].label shouldBe "label3"
        irProg.chunks()[0].isEmpty() shouldBe true
-        irProg.chunks()[1].isEmpty() shouldBe true
-        irProg.chunks()[2].isEmpty() shouldBe false
-        irProg.chunks()[3].isEmpty() shouldBe true
+        irProg.chunks()[1].isEmpty() shouldBe false
+        irProg.chunks()[2].isEmpty() shouldBe true
        val instr = irProg.chunks().flatMap { it.instructions }
        instr.size shouldBe 2
        instr[0].opcode shouldBe Opcode.JUMP
@@ -92,7 +91,7 @@ class TestIRPeepholeOpt: FunSpec({
        ))
        irProg.chunks().single().instructions.size shouldBe 6
        val opt = IRPeepholeOptimizer(irProg)
-        opt.optimize()
+        opt.optimize(true, ErrorReporterForTests())
        val instr = irProg.chunks().single().instructions
        instr.size shouldBe 1
        instr[0].opcode shouldBe Opcode.CLC
@@ -107,7 +106,7 @@ class TestIRPeepholeOpt: FunSpec({
        ))
        irProg.chunks().single().instructions.size shouldBe 4
        val opt = IRPeepholeOptimizer(irProg)
-        opt.optimize()
+        opt.optimize(true, ErrorReporterForTests())
        val instr = irProg.chunks().single().instructions
        instr.size shouldBe 1
        instr[0].opcode shouldBe Opcode.LOADR
@@ -130,7 +129,7 @@ class TestIRPeepholeOpt: FunSpec({
        ))
        irProg.chunks().single().instructions.size shouldBe 10
        val opt = IRPeepholeOptimizer(irProg)
-        opt.optimize()
+        opt.optimize(true, ErrorReporterForTests())
        irProg.chunks().single().instructions.size shouldBe 4
    }

@@ -141,7 +140,7 @@ class TestIRPeepholeOpt: FunSpec({
        ))
        irProg.chunks().single().instructions.size shouldBe 2
        val opt = IRPeepholeOptimizer(irProg)
-        opt.optimize()
+        opt.optimize(true, ErrorReporterForTests())
        val instr = irProg.chunks().single().instructions
        instr.size shouldBe 2
        instr[0].opcode shouldBe Opcode.INC
@@ -161,7 +160,7 @@ class TestIRPeepholeOpt: FunSpec({
        ))
        irProg.chunks().single().instructions.size shouldBe 8
        val opt = IRPeepholeOptimizer(irProg)
-        opt.optimize()
+        opt.optimize(true, ErrorReporterForTests())
        irProg.chunks().single().instructions.size shouldBe 4
    }

@@ -174,7 +173,7 @@ class TestIRPeepholeOpt: FunSpec({
        ))
        irProg.chunks().single().instructions.size shouldBe 4
        val opt = IRPeepholeOptimizer(irProg)
-        opt.optimize()
+        opt.optimize(true, ErrorReporterForTests())
        val instr = irProg.chunks().single().instructions
        instr.size shouldBe 4
        instr[0].opcode shouldBe Opcode.LOAD
@@ -19,6 +19,7 @@ class TestVmCodeGen: FunSpec({
            CbmPrgLauncherType.NONE,
            ZeropageType.DONTUSE,
            zpReserved = emptyList(),
+            zpAllowed = CompilationOptions.AllZeropageAllowed,
            floats = true,
            noSysInit = false,
            compTarget = target,
@@ -41,7 +42,7 @@ class TestVmCodeGen: FunSpec({
 //}
        val codegen = VmCodeGen()
        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))
@@ -91,7 +92,7 @@ class TestVmCodeGen: 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)

@@ -120,11 +121,11 @@ class TestVmCodeGen: FunSpec({
 //}
        val codegen = VmCodeGen()
        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("f1", DataType.FLOAT, ZeropageWish.DONTCARE, null, null, Position.DUMMY))
        val if1 = PtIfElse(Position.DUMMY)
-        val cmp1 = PtBinaryExpression("==", DataType.UBYTE, Position.DUMMY)
+        val cmp1 = PtBinaryExpression("==", DataType.BOOL, Position.DUMMY)
        cmp1.add(PtIdentifier("main.start.f1", DataType.FLOAT, Position.DUMMY))
        cmp1.add(PtNumber(DataType.FLOAT, 0.0, Position.DUMMY))
        if1.add(cmp1)
@@ -132,7 +133,7 @@ class TestVmCodeGen: FunSpec({
        if1.add(PtNodeGroup().also { it.add(PtNop(Position.DUMMY)) })
        sub.add(if1)
        val if2 = PtIfElse(Position.DUMMY)
-        val cmp2 = PtBinaryExpression("!=", DataType.UBYTE, Position.DUMMY)
+        val cmp2 = PtBinaryExpression("!=", DataType.BOOL, Position.DUMMY)
        cmp2.add(PtIdentifier("main.start.f1", DataType.FLOAT, Position.DUMMY))
        cmp2.add(PtNumber(DataType.FLOAT, 0.0, Position.DUMMY))
        if2.add(cmp2)
@@ -140,7 +141,7 @@ class TestVmCodeGen: FunSpec({
        if2.add(PtNodeGroup().also { it.add(PtNop(Position.DUMMY)) })
        sub.add(if2)
        val if3 = PtIfElse(Position.DUMMY)
-        val cmp3 = PtBinaryExpression("<", DataType.UBYTE, Position.DUMMY)
+        val cmp3 = PtBinaryExpression("<", DataType.BOOL, Position.DUMMY)
        cmp3.add(PtIdentifier("main.start.f1", DataType.FLOAT, Position.DUMMY))
        cmp3.add(PtNumber(DataType.FLOAT, 0.0, Position.DUMMY))
        if3.add(cmp3)
@@ -148,7 +149,7 @@ class TestVmCodeGen: FunSpec({
        if3.add(PtNodeGroup().also { it.add(PtNop(Position.DUMMY)) })
        sub.add(if3)
        val if4 = PtIfElse(Position.DUMMY)
-        val cmp4 = PtBinaryExpression(">", DataType.UBYTE, Position.DUMMY)
+        val cmp4 = PtBinaryExpression(">", DataType.BOOL, Position.DUMMY)
        cmp4.add(PtIdentifier("main.start.f1", DataType.FLOAT, Position.DUMMY))
        cmp4.add(PtNumber(DataType.FLOAT, 0.0, Position.DUMMY))
        if4.add(cmp4)
@@ -183,11 +184,11 @@ class TestVmCodeGen: FunSpec({
 //}
        val codegen = VmCodeGen()
        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("f1", DataType.FLOAT, ZeropageWish.DONTCARE, null, null, Position.DUMMY))
        val if1 = PtIfElse(Position.DUMMY)
-        val cmp1 = PtBinaryExpression("==", DataType.UBYTE, Position.DUMMY)
+        val cmp1 = PtBinaryExpression("==", DataType.BOOL, Position.DUMMY)
        cmp1.add(PtIdentifier("main.start.f1", DataType.FLOAT, Position.DUMMY))
        cmp1.add(PtNumber(DataType.FLOAT, 42.0, Position.DUMMY))
        if1.add(cmp1)
@@ -195,7 +196,7 @@ class TestVmCodeGen: FunSpec({
        if1.add(PtNodeGroup().also { it.add(PtNop(Position.DUMMY)) })
        sub.add(if1)
        val if2 = PtIfElse(Position.DUMMY)
-        val cmp2 = PtBinaryExpression("!=", DataType.UBYTE, Position.DUMMY)
+        val cmp2 = PtBinaryExpression("!=", DataType.BOOL, Position.DUMMY)
        cmp2.add(PtIdentifier("main.start.f1", DataType.FLOAT, Position.DUMMY))
        cmp2.add(PtNumber(DataType.FLOAT, 42.0, Position.DUMMY))
        if2.add(cmp2)
@@ -203,7 +204,7 @@ class TestVmCodeGen: FunSpec({
        if2.add(PtNodeGroup().also { it.add(PtNop(Position.DUMMY)) })
        sub.add(if2)
        val if3 = PtIfElse(Position.DUMMY)
-        val cmp3 = PtBinaryExpression("<", DataType.UBYTE, Position.DUMMY)
+        val cmp3 = PtBinaryExpression("<", DataType.BOOL, Position.DUMMY)
        cmp3.add(PtIdentifier("main.start.f1", DataType.FLOAT, Position.DUMMY))
        cmp3.add(PtNumber(DataType.FLOAT, 42.0, Position.DUMMY))
        if3.add(cmp3)
@@ -211,7 +212,7 @@ class TestVmCodeGen: FunSpec({
        if3.add(PtNodeGroup().also { it.add(PtNop(Position.DUMMY)) })
        sub.add(if3)
        val if4 = PtIfElse(Position.DUMMY)
-        val cmp4 = PtBinaryExpression(">", DataType.UBYTE, Position.DUMMY)
+        val cmp4 = PtBinaryExpression(">", DataType.BOOL, Position.DUMMY)
        cmp4.add(PtIdentifier("main.start.f1", DataType.FLOAT, Position.DUMMY))
        cmp4.add(PtNumber(DataType.FLOAT, 42.0, Position.DUMMY))
        if4.add(cmp4)
@@ -242,23 +243,23 @@ class TestVmCodeGen: FunSpec({
 //}
        val codegen = VmCodeGen()
        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("f1", DataType.FLOAT, ZeropageWish.DONTCARE, null, null, Position.DUMMY))
        val if1 = PtIfElse(Position.DUMMY)
-        val cmp1 = PtBinaryExpression("==", DataType.UBYTE, Position.DUMMY)
+        val cmp1 = PtBinaryExpression("==", DataType.BOOL, Position.DUMMY)
        cmp1.add(PtIdentifier("main.start.f1", DataType.FLOAT, Position.DUMMY))
        cmp1.add(PtNumber(DataType.FLOAT, 42.0, Position.DUMMY))
        if1.add(cmp1)
-        if1.add(PtNodeGroup().also { it.add(PtJump(null, 0xc000u, null, Position.DUMMY)) })
+        if1.add(PtNodeGroup().also { it.add(PtJump(null, 0xc000u, Position.DUMMY)) })
        if1.add(PtNodeGroup())
        sub.add(if1)
        val if2 = PtIfElse(Position.DUMMY)
-        val cmp2 = PtBinaryExpression(">", DataType.UBYTE, Position.DUMMY)
+        val cmp2 = PtBinaryExpression(">", DataType.BOOL, Position.DUMMY)
        cmp2.add(PtIdentifier("main.start.f1", DataType.FLOAT, Position.DUMMY))
        cmp2.add(PtNumber(DataType.FLOAT, 42.0, Position.DUMMY))
        if2.add(cmp2)
-        if2.add(PtNodeGroup().also { it.add(PtJump(null, 0xc000u, null, Position.DUMMY)) })
+        if2.add(PtNodeGroup().also { it.add(PtJump(null, 0xc000u, Position.DUMMY)) })
        if2.add(PtNodeGroup())
        sub.add(if2)
        block.add(sub)
@@ -289,11 +290,11 @@ class TestVmCodeGen: FunSpec({
 //}
        val codegen = VmCodeGen()
        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("sb1", DataType.BYTE, ZeropageWish.DONTCARE, null, null, Position.DUMMY))
        val if1 = PtIfElse(Position.DUMMY)
-        val cmp1 = PtBinaryExpression("==", DataType.BYTE, Position.DUMMY)
+        val cmp1 = PtBinaryExpression("==", DataType.BOOL, Position.DUMMY)
        cmp1.add(PtIdentifier("main.start.sb1", DataType.BYTE, Position.DUMMY))
        cmp1.add(PtNumber(DataType.BYTE, 0.0, Position.DUMMY))
        if1.add(cmp1)
@@ -301,7 +302,7 @@ class TestVmCodeGen: FunSpec({
        if1.add(PtNodeGroup().also { it.add(PtNop(Position.DUMMY)) })
        sub.add(if1)
        val if2 = PtIfElse(Position.DUMMY)
-        val cmp2 = PtBinaryExpression("!=", DataType.BYTE, Position.DUMMY)
+        val cmp2 = PtBinaryExpression("!=", DataType.BOOL, Position.DUMMY)
        cmp2.add(PtIdentifier("main.start.sb1", DataType.BYTE, Position.DUMMY))
        cmp2.add(PtNumber(DataType.BYTE, 0.0, Position.DUMMY))
        if2.add(cmp2)
@@ -309,7 +310,7 @@ class TestVmCodeGen: FunSpec({
        if2.add(PtNodeGroup().also { it.add(PtNop(Position.DUMMY)) })
        sub.add(if2)
        val if3 = PtIfElse(Position.DUMMY)
-        val cmp3 = PtBinaryExpression("<", DataType.BYTE, Position.DUMMY)
+        val cmp3 = PtBinaryExpression("<", DataType.BOOL, Position.DUMMY)
        cmp3.add(PtIdentifier("main.start.sb1", DataType.BYTE, Position.DUMMY))
        cmp3.add(PtNumber(DataType.BYTE, 0.0, Position.DUMMY))
        if3.add(cmp3)
@@ -317,7 +318,7 @@ class TestVmCodeGen: FunSpec({
        if3.add(PtNodeGroup().also { it.add(PtNop(Position.DUMMY)) })
        sub.add(if3)
        val if4 = PtIfElse(Position.DUMMY)
-        val cmp4 = PtBinaryExpression(">", DataType.BYTE, Position.DUMMY)
+        val cmp4 = PtBinaryExpression(">", DataType.BOOL, Position.DUMMY)
        cmp4.add(PtIdentifier("main.start.sb1", DataType.BYTE, Position.DUMMY))
        cmp4.add(PtNumber(DataType.BYTE, 0.0, Position.DUMMY))
        if4.add(cmp4)
@@ -352,11 +353,11 @@ class TestVmCodeGen: FunSpec({
 //}
        val codegen = VmCodeGen()
        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("sb1", DataType.BYTE, ZeropageWish.DONTCARE, null, null, Position.DUMMY))
        val if1 = PtIfElse(Position.DUMMY)
-        val cmp1 = PtBinaryExpression("==", DataType.BYTE, Position.DUMMY)
+        val cmp1 = PtBinaryExpression("==", DataType.BOOL, Position.DUMMY)
        cmp1.add(PtIdentifier("main.start.sb1", DataType.BYTE, Position.DUMMY))
        cmp1.add(PtNumber(DataType.BYTE, 42.0, Position.DUMMY))
        if1.add(cmp1)
@@ -364,7 +365,7 @@ class TestVmCodeGen: FunSpec({
        if1.add(PtNodeGroup().also { it.add(PtNop(Position.DUMMY)) })
        sub.add(if1)
        val if2 = PtIfElse(Position.DUMMY)
-        val cmp2 = PtBinaryExpression("!=", DataType.BYTE, Position.DUMMY)
+        val cmp2 = PtBinaryExpression("!=", DataType.BOOL, Position.DUMMY)
        cmp2.add(PtIdentifier("main.start.sb1", DataType.BYTE, Position.DUMMY))
        cmp2.add(PtNumber(DataType.BYTE, 42.0, Position.DUMMY))
        if2.add(cmp2)
@@ -372,7 +373,7 @@ class TestVmCodeGen: FunSpec({
        if2.add(PtNodeGroup().also { it.add(PtNop(Position.DUMMY)) })
        sub.add(if2)
        val if3 = PtIfElse(Position.DUMMY)
-        val cmp3 = PtBinaryExpression("<", DataType.BYTE, Position.DUMMY)
+        val cmp3 = PtBinaryExpression("<", DataType.BOOL, Position.DUMMY)
        cmp3.add(PtIdentifier("main.start.sb1", DataType.BYTE, Position.DUMMY))
        cmp3.add(PtNumber(DataType.BYTE, 42.0, Position.DUMMY))
        if3.add(cmp3)
@@ -380,7 +381,7 @@ class TestVmCodeGen: FunSpec({
        if3.add(PtNodeGroup().also { it.add(PtNop(Position.DUMMY)) })
        sub.add(if3)
        val if4 = PtIfElse(Position.DUMMY)
-        val cmp4 = PtBinaryExpression(">", DataType.BYTE, Position.DUMMY)
+        val cmp4 = PtBinaryExpression(">", DataType.BOOL, Position.DUMMY)
        cmp4.add(PtIdentifier("main.start.sb1", DataType.BYTE, Position.DUMMY))
        cmp4.add(PtNumber(DataType.BYTE, 42.0, Position.DUMMY))
        if4.add(cmp4)
@@ -411,23 +412,23 @@ class TestVmCodeGen: FunSpec({
 //}
        val codegen = VmCodeGen()
        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("ub1", DataType.UBYTE, ZeropageWish.DONTCARE, null, null, Position.DUMMY))
        val if1 = PtIfElse(Position.DUMMY)
-        val cmp1 = PtBinaryExpression("==", DataType.UBYTE, Position.DUMMY)
+        val cmp1 = PtBinaryExpression("==", DataType.BOOL, Position.DUMMY)
        cmp1.add(PtIdentifier("main.start.ub1", DataType.UBYTE, Position.DUMMY))
        cmp1.add(PtNumber(DataType.UBYTE, 42.0, Position.DUMMY))
        if1.add(cmp1)
-        if1.add(PtNodeGroup().also { it.add(PtJump(null, 0xc000u, null, Position.DUMMY)) })
+        if1.add(PtNodeGroup().also { it.add(PtJump(null, 0xc000u, Position.DUMMY)) })
        if1.add(PtNodeGroup())
        sub.add(if1)
        val if2 = PtIfElse(Position.DUMMY)
-        val cmp2 = PtBinaryExpression(">", DataType.UBYTE, Position.DUMMY)
+        val cmp2 = PtBinaryExpression(">", DataType.BOOL, Position.DUMMY)
        cmp2.add(PtIdentifier("main.start.ub1", DataType.UBYTE, Position.DUMMY))
        cmp2.add(PtNumber(DataType.UBYTE, 42.0, Position.DUMMY))
        if2.add(cmp2)
-        if2.add(PtNodeGroup().also { it.add(PtJump(null, 0xc000u, null, Position.DUMMY)) })
+        if2.add(PtNodeGroup().also { it.add(PtJump(null, 0xc000u, Position.DUMMY)) })
        if2.add(PtNodeGroup())
        sub.add(if2)
        block.add(sub)
@@ -441,7 +442,7 @@ class TestVmCodeGen: FunSpec({
        irChunks.size shouldBe 1
    }

-    test("romsub allowed in codegen") {
+    test("romsub allowed in ir-codegen") {
 //main {
 //    romsub $5000 = routine()
 //
@@ -451,8 +452,8 @@ class TestVmCodeGen: FunSpec({
 //}
        val codegen = VmCodeGen()
        val program = PtProgram("test", DummyMemsizer, DummyStringEncoder)
-        val block = PtBlock("main", null, false, false, PtBlock.BlockAlignment.NONE, SourceCode.Generated("test"), Position.DUMMY)
-        val romsub = PtAsmSub("routine", 0x5000u, emptySet(), emptyList(), emptyList(), false, Position.DUMMY)
+        val block = PtBlock("main", false, SourceCode.Generated("test"), PtBlock.Options(), Position.DUMMY)
+        val romsub = PtAsmSub("routine", 0x5000u, setOf(CpuRegister.Y), emptyList(), emptyList(), false, Position.DUMMY)
        block.add(romsub)
        val sub = PtSub("start", emptyList(), null, Position.DUMMY)
        val call = PtFunctionCall("main.routine", true, DataType.UNDEFINED, Position.DUMMY)
@@ -466,7 +467,11 @@ class TestVmCodeGen: FunSpec({
        val result = codegen.generate(program, st, options, errors) as VmAssemblyProgram
        val irChunks = (result.irProgram.blocks.first().children.single() as IRSubroutine).chunks
        irChunks.size shouldBe 1
-        val callInstr = irChunks.single().instructions.single()
+        irChunks[0].instructions.size shouldBe 2
+        val preparecallInstr = irChunks[0].instructions[0]
+        preparecallInstr.opcode shouldBe Opcode.PREPARECALL
+        preparecallInstr.immediate shouldBe 0
+        val callInstr = irChunks[0].instructions[1]
        callInstr.opcode shouldBe Opcode.CALL
        callInstr.address shouldBe 0x5000
    }
@@ -27,16 +27,17 @@ dependencies {
    implementation project(':codeCore')
    implementation project(':compilerAst')
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
+    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.20"
    // implementation "org.jetbrains.kotlin:kotlin-reflect"
 }

 sourceSets {
    main {
        java {
-            srcDirs = ["${project.projectDir}/src"]
+            srcDir "${project.projectDir}/src"
        }
        resources {
-            srcDirs = ["${project.projectDir}/res"]
+            srcDir "${project.projectDir}/res"
        }
    }
 }
@@ -11,5 +11,6 @@
    <orderEntry type="library" name="KotlinJavaRuntime" level="project" />
    <orderEntry type="module" module-name="codeCore" />
    <orderEntry type="module" module-name="compilerAst" />
+    <orderEntry type="library" name="michael.bull.kotlin.result.jvm" level="project" />
  </component>
 </module>
@@ -1,71 +0,0 @@
-package prog8.optimizer
-
-import prog8.ast.IStatementContainer
-import prog8.ast.Node
-import prog8.ast.Program
-import prog8.ast.expressions.BinaryExpression
-import prog8.ast.statements.AssignTarget
-import prog8.ast.statements.Assignment
-import prog8.ast.statements.AssignmentOrigin
-import prog8.ast.walk.AstWalker
-import prog8.ast.walk.IAstModification
-import prog8.code.core.AugmentAssignmentOperators
-import prog8.code.core.CompilationOptions
-import prog8.code.core.DataType
-import prog8.code.target.VMTarget
-
-
-class BinExprSplitter(private val program: Program, private val options: CompilationOptions) : AstWalker() {
-
-    override fun after(assignment: Assignment, parent: Node): Iterable<IAstModification> {
-
-        if(options.compTarget.name == VMTarget.NAME)
-            return noModifications  // don't split expressions when targeting the vm codegen, it handles nested expressions well
-
-        if(assignment.value.inferType(program) istype DataType.FLOAT && !options.optimizeFloatExpressions)
-            return noModifications
-
-        val binExpr = assignment.value as? BinaryExpression
-        if (binExpr != null) {
-
-            if(binExpr.operator in AugmentAssignmentOperators && isSimpleTarget(assignment.target)) {
-                if(assignment.target isSameAs binExpr.right)
-                    return noModifications
-                if(assignment.target isSameAs binExpr.left) {
-                    if(binExpr.right.isSimple)
-                        return noModifications
-                    val leftBx = binExpr.left as? BinaryExpression
-                    if(leftBx!=null && (!leftBx.left.isSimple || !leftBx.right.isSimple))
-                        return noModifications
-                    val rightBx = binExpr.right as? BinaryExpression
-                    if(rightBx!=null && (!rightBx.left.isSimple || !rightBx.right.isSimple))
-                        return noModifications
-                }
-
-                if(binExpr.right.isSimple) {
-                    val firstAssign = Assignment(assignment.target.copy(), binExpr.left, AssignmentOrigin.OPTIMIZER, binExpr.left.position)
-                    val targetExpr = assignment.target.toExpression()
-                    val augExpr = BinaryExpression(targetExpr, binExpr.operator, binExpr.right, binExpr.right.position)
-                    return listOf(
-                        IAstModification.ReplaceNode(binExpr, augExpr, assignment),
-                        IAstModification.InsertBefore(assignment, firstAssign, assignment.parent as IStatementContainer)
-                    )
-                }
-            }
-
-            // Further unraveling of binary expressions is really complicated here and
-            // often results in much bigger code, thereby defeating the purpose a bit.
-            // All in all this should probably be fixed in a better code generation backend
-            // that doesn't require this at all.
-        }
-
-        return noModifications
-    }
-
-    private fun isSimpleTarget(target: AssignTarget) =
-            if (target.identifier!=null || target.memoryAddress!=null)
-                !target.isIOAddress(options.compTarget.machine)
-            else
-                false
-
-}