version 8.6.1

Fixed by reintroducing splitting of comparison expression in if statements by using a temporary variable and/or register to precompute left/right values.

.idea/libraries/io_kotest_assertions_core_jvm.xml

@@ -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:5.1.0" />
+    <properties maven-id="io.kotest:kotest-assertions-core-jvm:5.3.2" />
     <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.1.0/kotest-assertions-core-jvm-5.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.6.10/kotlin-stdlib-jdk8-1.6.10.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.6.10/kotlin-stdlib-1.6.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.3.2/kotest-assertions-core-jvm-5.3.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.6.21/kotlin-stdlib-jdk8-1.6.21.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.6.21/kotlin-stdlib-1.6.21.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.6.10/kotlin-stdlib-jdk7-1.6.10.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.1.0/kotest-assertions-shared-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.6.21/kotlin-stdlib-jdk7-1.6.21.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.3.2/kotest-assertions-shared-jvm-5.3.2.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/io/github/java-diff-utils/java-diff-utils/4.11/java-diff-utils-4.11.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.6.0/kotlinx-coroutines-jdk8-1.6.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.6.10/kotlin-reflect-1.6.10.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.0/kotlinx-coroutines-core-jvm-1.6.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.6.1/kotlinx-coroutines-jdk8-1.6.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.6.21/kotlin-reflect-1.6.21.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.1/kotlinx-coroutines-core-jvm-1.6.1.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.6.0/kotlin-stdlib-common-1.6.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.1.0/kotest-common-jvm-5.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.1.0/kotest-assertions-api-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.3.2/kotest-common-jvm-5.3.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.3.2/kotest-assertions-api-jvm-5.3.2.jar!/" />
     </CLASSES>
     <JAVADOC />
     <SOURCES />

.idea/libraries/io_kotest_property_jvm.xml

@@ -1,22 +1,22 @@
 <component name="libraryTable">
   <library name="io.kotest.property.jvm" type="repository">
-    <properties maven-id="io.kotest:kotest-property-jvm:5.1.0" />
+    <properties maven-id="io.kotest:kotest-property-jvm:5.3.2" />
     <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-property-jvm/5.1.0/kotest-property-jvm-5.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.1.0/kotest-common-jvm-5.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.1.0/kotest-assertions-shared-jvm-5.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.1.0/kotest-assertions-api-jvm-5.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.6.0/kotlinx-coroutines-jdk8-1.6.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.6.10/kotlin-stdlib-jdk8-1.6.10.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.6.10/kotlin-stdlib-1.6.10.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.6.10/kotlin-stdlib-jdk7-1.6.10.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.6.10/kotlin-reflect-1.6.10.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.0/kotlinx-coroutines-core-jvm-1.6.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.6.0/kotlin-stdlib-common-1.6.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/github/java-diff-utils/java-diff-utils/4.11/java-diff-utils-4.11.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-property-jvm/5.3.2/kotest-property-jvm-5.3.2.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/com/github/curious-odd-man/rgxgen/1.3/rgxgen-1.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.6.21/kotlin-stdlib-jdk8-1.6.21.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.6.21/kotlin-stdlib-1.6.21.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.6.21/kotlin-stdlib-jdk7-1.6.21.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.3.2/kotest-common-jvm-5.3.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.3.2/kotest-assertions-shared-jvm-5.3.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.3.2/kotest-assertions-api-jvm-5.3.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.6.1/kotlinx-coroutines-jdk8-1.6.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/github/java-diff-utils/java-diff-utils/4.11/java-diff-utils-4.11.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.6.21/kotlin-reflect-1.6.21.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.1/kotlinx-coroutines-core-jvm-1.6.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.6.0/kotlin-stdlib-common-1.6.0.jar!/" />
     </CLASSES>
     <JAVADOC />
     <SOURCES />

.idea/libraries/io_kotest_runner_junit5_jvm.xml

@@ -1,39 +1,39 @@
 <component name="libraryTable">
   <library name="io.kotest.runner.junit5.jvm" type="repository">
-    <properties maven-id="io.kotest:kotest-runner-junit5-jvm:5.1.0" />
+    <properties maven-id="io.kotest:kotest-runner-junit5-jvm:5.3.2" />
     <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-runner-junit5-jvm/5.1.0/kotest-runner-junit5-jvm-5.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-api-jvm/5.1.0/kotest-framework-api-jvm-5.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-test-jvm/1.6.0/kotlinx-coroutines-test-jvm-1.6.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.1.0/kotest-assertions-shared-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-runner-junit5-jvm/5.3.2/kotest-runner-junit5-jvm-5.3.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-api-jvm/5.3.2/kotest-framework-api-jvm-5.3.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-shared-jvm/5.3.2/kotest-assertions-shared-jvm-5.3.2.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/io/github/java-diff-utils/java-diff-utils/4.11/java-diff-utils-4.11.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.1.0/kotest-common-jvm-5.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-engine-jvm/5.1.0/kotest-framework-engine-jvm-5.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/github/classgraph/classgraph/4.8.138/classgraph-4.8.138.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-test-jvm/1.6.1/kotlinx-coroutines-test-jvm-1.6.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-common-jvm/5.3.2/kotest-common-jvm-5.3.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-engine-jvm/5.3.2/kotest-framework-engine-jvm-5.3.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/github/classgraph/classgraph/4.8.146/classgraph-4.8.146.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/com/github/ajalt/mordant/1.2.1/mordant-1.2.1.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/com/github/ajalt/colormath/1.2.0/colormath-1.2.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-debug/1.6.0/kotlinx-coroutines-debug-1.6.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-debug/1.6.1/kotlinx-coroutines-debug-1.6.1.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/net/java/dev/jna/jna/5.9.0/jna-5.9.0.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/net/java/dev/jna/jna-platform/5.9.0/jna-platform-5.9.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-discovery-jvm/5.1.0/kotest-framework-discovery-jvm-5.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.1.0/kotest-assertions-core-jvm-5.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.6.0/kotlinx-coroutines-jdk8-1.6.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.1.0/kotest-assertions-api-jvm-5.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-extensions-jvm/5.1.0/kotest-extensions-jvm-5.1.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-discovery-jvm/5.3.2/kotest-framework-discovery-jvm-5.3.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-core-jvm/5.3.2/kotest-assertions-core-jvm-5.3.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-jdk8/1.6.1/kotlinx-coroutines-jdk8-1.6.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-assertions-api-jvm/5.3.2/kotest-assertions-api-jvm-5.3.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-extensions-jvm/5.3.2/kotest-extensions-jvm-5.3.2.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/commons-io/commons-io/2.11.0/commons-io-2.11.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk/1.12.2/mockk-1.12.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-dsl-jvm/1.12.2/mockk-dsl-jvm-1.12.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-dsl/1.12.2/mockk-dsl-1.12.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-common/1.12.2/mockk-common-1.12.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-agent-jvm/1.12.2/mockk-agent-jvm-1.12.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-agent-api/1.12.2/mockk-agent-api-1.12.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-agent-common/1.12.2/mockk-agent-common-1.12.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk/1.12.3/mockk-1.12.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-common/1.12.3/mockk-common-1.12.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-dsl/1.12.3/mockk-dsl-1.12.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-dsl-jvm/1.12.3/mockk-dsl-jvm-1.12.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-agent-jvm/1.12.3/mockk-agent-jvm-1.12.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-agent-api/1.12.3/mockk-agent-api-1.12.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/mockk/mockk-agent-common/1.12.3/mockk-agent-common-1.12.3.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/org/objenesis/objenesis/3.1/objenesis-3.1.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/net/bytebuddy/byte-buddy/1.12.5/byte-buddy-1.12.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/net/bytebuddy/byte-buddy-agent/1.12.5/byte-buddy-agent-1.12.5.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-concurrency-jvm/5.1.0/kotest-framework-concurrency-jvm-5.1.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.0/kotlinx-coroutines-core-jvm-1.6.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/net/bytebuddy/byte-buddy/1.12.6/byte-buddy-1.12.6.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/net/bytebuddy/byte-buddy-agent/1.12.6/byte-buddy-agent-1.12.6.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/io/kotest/kotest-framework-concurrency-jvm/5.3.2/kotest-framework-concurrency-jvm-5.3.2.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.1/kotlinx-coroutines-core-jvm-1.6.1.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.6.0/kotlin-stdlib-common-1.6.0.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-engine/1.7.2/junit-platform-engine-1.7.2.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/org/apiguardian/apiguardian-api/1.1.0/apiguardian-api-1.1.0.jar!/" />
@@ -41,11 +41,11 @@
       <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-suite-api/1.7.2/junit-platform-suite-api-1.7.2.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-launcher/1.7.2/junit-platform-launcher-1.7.2.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-api/5.7.2/junit-jupiter-api-5.7.2.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.6.10/kotlin-stdlib-jdk8-1.6.10.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.6.10/kotlin-stdlib-1.6.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/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-jdk7/1.6.10/kotlin-stdlib-jdk7-1.6.10.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-reflect/1.6.10/kotlin-reflect-1.6.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/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!/" />
     </CLASSES>
     <JAVADOC />
     <SOURCES />

.idea/libraries/michael_bull_kotlin_result_jvm.xml

@@ -1,13 +1,13 @@
 <component name="libraryTable">
   <library name="michael.bull.kotlin.result.jvm" type="repository">
-    <properties maven-id="com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.14" />
+    <properties maven-id="com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.16" />
     <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/com/michael-bull/kotlin-result/kotlin-result-jvm/1.1.14/kotlin-result-jvm-1.1.14.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk8/1.6.10/kotlin-stdlib-jdk8-1.6.10.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib/1.6.10/kotlin-stdlib-1.6.10.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/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://$MAVEN_REPOSITORY$/org/jetbrains/annotations/13.0/annotations-13.0.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-jdk7/1.6.10/kotlin-stdlib-jdk7-1.6.10.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/jetbrains/kotlin/kotlin-stdlib-common/1.6.10/kotlin-stdlib-common-1.6.10.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 />

.idea/libraries/takes.xml

@@ -1,11 +1,15 @@
 <component name="libraryTable">
   <library name="takes" type="repository">
-    <properties maven-id="org.takes:takes:1.19" />
+    <properties maven-id="org.takes:takes:1.20" />
     <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/takes/takes/1.19/takes-1.19.jar!/" />
-      <root url="jar://$MAVEN_REPOSITORY$/org/cactoos/cactoos/0.42/cactoos-0.42.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/takes/takes/1.20/takes-1.20.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/cactoos/cactoos/0.50/cactoos-0.50.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/javax/xml/bind/jaxb-api/2.3.0/jaxb-api-2.3.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/slf4j/slf4j-api/1.7.25/slf4j-api-1.7.25.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/org/apache/commons/commons-text/1.4/commons-text-1.4.jar!/" />
       <root url="jar://$MAVEN_REPOSITORY$/org/apache/commons/commons-lang3/3.7/commons-lang3-3.7.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/com/sun/xml/bind/jaxb-core/2.3.0/jaxb-core-2.3.0.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/com/sun/xml/bind/jaxb-impl/2.3.0/jaxb-impl-2.3.0.jar!/" />
     </CLASSES>
     <JAVADOC />
     <SOURCES />

.idea/misc.xml

@@ -19,7 +19,7 @@
   <component name="FrameworkDetectionExcludesConfiguration">
     <type id="Python" />
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" project-jdk-name="11" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="true" project-jdk-name="11" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>

.idea/modules.xml

@@ -2,10 +2,10 @@
 <project version="4">
   <component name="ProjectModuleManager">
     <modules>
-      <module fileurl="file://$PROJECT_DIR$/codeAst/codeAst.iml" filepath="$PROJECT_DIR$/codeAst/codeAst.iml" />
       <module fileurl="file://$PROJECT_DIR$/codeCore/codeCore.iml" filepath="$PROJECT_DIR$/codeCore/codeCore.iml" />
       <module fileurl="file://$PROJECT_DIR$/codeGenCpu6502/codeGenCpu6502.iml" filepath="$PROJECT_DIR$/codeGenCpu6502/codeGenCpu6502.iml" />
       <module fileurl="file://$PROJECT_DIR$/codeGenExperimental/codeGenExperimental.iml" filepath="$PROJECT_DIR$/codeGenExperimental/codeGenExperimental.iml" />
+      <module fileurl="file://$PROJECT_DIR$/codeGenIntermediate/codeGenIntermediate.iml" filepath="$PROJECT_DIR$/codeGenIntermediate/codeGenIntermediate.iml" />
       <module fileurl="file://$PROJECT_DIR$/codeGenVirtual/codeGenVirtual.iml" filepath="$PROJECT_DIR$/codeGenVirtual/codeGenVirtual.iml" />
       <module fileurl="file://$PROJECT_DIR$/codeOptimizers/codeOptimizers.iml" filepath="$PROJECT_DIR$/codeOptimizers/codeOptimizers.iml" />
       <module fileurl="file://$PROJECT_DIR$/compiler/compiler.iml" filepath="$PROJECT_DIR$/compiler/compiler.iml" />
@@ -14,6 +14,7 @@
       <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" />
     </modules>

LICENSE

@@ -1,9 +1,9 @@
 
-This sofware license is for Prog8 the compiler + associated libraries.
+This sofware license is for Prog8 the compiler + associated library files.
 
-Any and all outputs generated by the compiler (intermediary
-source code and compiled binary programs) are excluded from that
-and you can do with them whatever you want.
+Exception: All output files generated by the compiler (intermediary files
+and compiled binary programs) are excluded from this; you can do with those
+whatever you want.
 
 
 

README.md

@@ -16,10 +16,11 @@ https://prog8.readthedocs.io/
 
 Software license
 ----------------
-GNU GPL 3.0, see file LICENSE
+GNU GPL 3.0 (see file LICENSE), with exception for generated code:
 
-- prog8 (the compiler + libraries) is licensed under GNU GPL 3.0
-- *exception:* the resulting files created by running the compiler are free to use in whatever way desired.
+- The compiler and its libraries are free to use according to the terms of the GNU GPL 3.0
+- *exception:* the resulting files (intermediate source codes and resulting binary program) created by the compiler
+  are excluded from the GPL and are free to use in whatever way desired, commercially or not.
 
 
 What does Prog8 provide?

codeCore/build.gradle

@@ -26,7 +26,7 @@ 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:1.1.14"
+    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.16"
 }
 
 sourceSets {

codeCore/src/prog8/code/SymbolTable.kt

@@ -5,7 +5,7 @@ import prog8.code.core.*
 
 /**
  * Tree structure containing all symbol definitions in the program
- * (blocks, subroutines, variables (all types) and labels).
+ * (blocks, subroutines, variables (all types), memoryslabs, and labels).
  */
 class SymbolTable : StNode("", StNodeType.GLOBAL, Position.DUMMY) {
     fun print() = printIndented(0)
@@ -40,6 +40,24 @@ class SymbolTable : StNode("", StNodeType.GLOBAL, Position.DUMMY) {
         vars
     }
 
+    val allMemMappedVariables: Collection<StMemVar> by lazy {
+        val vars = mutableListOf<StMemVar>()
+        fun collect(node: StNode) {
+            for(child in node.children) {
+                if(child.value.type== StNodeType.MEMVAR)
+                    vars.add(child.value as StMemVar)
+                else
+                    collect(child.value)
+            }
+        }
+        collect(this)
+        vars
+    }
+
+    val allMemorySlabs: Collection<StMemorySlab> by lazy {
+        children.mapNotNull { if (it.value.type == StNodeType.MEMORYSLAB) it.value as StMemorySlab else null }
+    }
+
     override fun lookup(scopedName: List<String>) = flat[scopedName]
 }
 
@@ -54,7 +72,8 @@ enum class StNodeType {
     STATICVAR,
     MEMVAR,
     CONSTANT,
-    BUILTINFUNC
+    BUILTINFUNC,
+    MEMORYSLAB
 }
 
 
@@ -128,6 +147,7 @@ open class StNode(val name: String,
             StNodeType.LABEL -> print("(L) ")
             StNodeType.STATICVAR -> print("(V) ")
             StNodeType.MEMVAR -> print("(M) ")
+            StNodeType.MEMORYSLAB -> print("(MS) ")
             StNodeType.CONSTANT -> print("(C) ")
             StNodeType.BUILTINFUNC -> print("(F) ")
             StNodeType.ROMSUB -> print("(R) ")
@@ -149,26 +169,26 @@ open class StNode(val name: String,
 
 class StStaticVariable(name: String,
                        val dt: DataType,
-                       val initialNumericValue: Double?,
-                       val initialStringValue: StString?,
-                       val initialArrayValue: StArray?,
+                       val onetimeInitializationNumericValue: Double?,      // regular (every-run-time) initialization is done via regular assignments
+                       val onetimeInitializationStringValue: StString?,
+                       val onetimeInitializationArrayValue: StArray?,
                        val length: Int?,             // for arrays: the number of elements, for strings: number of characters *including* the terminating 0-byte
                        val zpwish: ZeropageWish,
                        position: Position) : StNode(name, StNodeType.STATICVAR, position) {
 
     init {
         if(length!=null) {
-            require(initialNumericValue == null)
-            if(initialArrayValue!=null)
-                require(length == initialArrayValue.size)
+            require(onetimeInitializationNumericValue == null)
+            if(onetimeInitializationArrayValue!=null)
+                require(length == onetimeInitializationArrayValue.size)
         }
-        if(initialNumericValue!=null)
+        if(onetimeInitializationNumericValue!=null)
             require(dt in NumericDatatypes)
-        if(initialArrayValue!=null)
+        if(onetimeInitializationArrayValue!=null)
             require(dt in ArrayDatatypes)
-        if(initialStringValue!=null) {
+        if(onetimeInitializationStringValue!=null) {
             require(dt == DataType.STR)
-            require(length == initialStringValue.first.length+1)
+            require(length == onetimeInitializationStringValue.first.length+1)
         }
     }
 
@@ -186,15 +206,30 @@ class StConstant(name: String, val dt: DataType, val value: Double, position: Po
 }
 
 
-class StMemVar(name: String, val dt: DataType, val address: UInt, position: Position) :
+class StMemVar(name: String,
+               val dt: DataType,
+               val address: UInt,
+               val length: Int?,             // for arrays: the number of elements, for strings: number of characters *including* the terminating 0-byte
+               position: Position) :
     StNode(name, StNodeType.MEMVAR, position) {
     override fun printProperties() {
         print("$name  dt=$dt address=${address.toHex()}")
     }
 }
 
+class StMemorySlab(
+    name: String,
+    val size: UInt,
+    val align: UInt,
+    position: Position
+):
+    StNode(name, StNodeType.MEMORYSLAB, position) {
+    override fun printProperties() {
+        print("$name  size=$size  align=$align")
+    }
+}
 
-class StSub(name: String, val parameters: List<StSubroutineParameter>, position: Position) :
+class StSub(name: String, val parameters: List<StSubroutineParameter>, val returnType: DataType?, position: Position) :
         StNode(name, StNodeType.SUBROUTINE, position) {
     override fun printProperties() {
         print(name)
@@ -202,7 +237,11 @@ class StSub(name: String, val parameters: List<StSubroutineParameter>, position:
 }
 
 
-class StRomSub(name: String, val address: UInt, parameters: List<StSubroutineParameter>, position: Position) :
+class StRomSub(name: String,
+               val address: UInt,
+               val parameters: List<StRomSubParameter>,
+               val returns: List<RegisterOrStatusflag>,
+               position: Position) :
     StNode(name, StNodeType.ROMSUB, position) {
     override fun printProperties() {
         print("$name  address=${address.toHex()}")
@@ -211,6 +250,7 @@ class StRomSub(name: String, val address: UInt, parameters: List<StSubroutinePar
 
 
 class StSubroutineParameter(val name: String, val type: DataType)
+class StRomSubParameter(val register: RegisterOrStatusflag, val type: DataType)
 class StArrayElement(val number: Double?, val addressOf: List<String>?)
 
 typealias StString = Pair<String, Encoding>

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

@@ -3,7 +3,7 @@ package prog8.code.ast
 import prog8.code.core.*
 import java.nio.file.Path
 
-// New (work-in-progress) simplified AST for the code generator.
+// New simplified AST for the code generator.
 
 
 sealed class PtNode(val position: Position) {

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

@@ -8,6 +8,21 @@ import kotlin.math.round
 
 
 sealed class PtExpression(val type: DataType, position: Position) : PtNode(position) {
+
+    init {
+        if(type==DataType.BOOL)
+            throw IllegalArgumentException("bool should have become ubyte @$position")
+        if(type==DataType.UNDEFINED) {
+            @Suppress("LeakingThis")
+            when(this) {
+                is PtBuiltinFunctionCall -> { /* void function call */ }
+                is PtFunctionCall -> { /* void function call */ }
+                is PtIdentifier -> { /* non-variable identifier */ }
+                else -> throw IllegalArgumentException("type should be known @$position")
+            }
+        }
+    }
+
     override fun printProperties() {
         print(type)
     }
@@ -73,6 +88,7 @@ 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
@@ -126,10 +142,12 @@ class PtMemoryByte(position: Position) : PtExpression(DataType.UBYTE, position)
 class PtNumber(type: DataType, val number: Double, position: Position) : PtExpression(type, position) {
 
     init {
+        if(type==DataType.BOOL)
+            throw IllegalArgumentException("bool should have become ubyte @$position")
         if(type!=DataType.FLOAT) {
             val rounded = round(number)
             if (rounded != number)
-                throw IllegalArgumentException("refused rounding of float to avoid loss of precision")
+                throw IllegalArgumentException("refused rounding of float to avoid loss of precision @$position")
         }
     }
 
@@ -149,23 +167,16 @@ class PtNumber(type: DataType, val number: Double, position: Position) : PtExpre
 }
 
 
-class PtPipe(type: DataType, val void: Boolean, position: Position) : PtExpression(type, position) {
-    init {
-        if(!void)
-            require(type!=DataType.UNDEFINED)
-    }
-
-    val segments: List<PtExpression>
-        get() = children.map { it as PtExpression }
-
-    override fun printProperties() {}
-}
-
-
 class PtPrefix(val operator: String, type: DataType, position: Position): PtExpression(type, position) {
     val value: PtExpression
         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
+        if(operator !in setOf("+", "-", "~"))
+            throw IllegalArgumentException("invalid prefix operator: $operator")
+    }
+
     override fun printProperties() {
         print(operator)
     }

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

@@ -8,6 +8,7 @@ class PtAsmSub(
     val address: UInt?,
     val clobbers: Set<CpuRegister>,
     val parameters: List<Pair<PtSubroutineParameter, RegisterOrStatusflag>>,
+    val returnTypes: List<DataType>,    // TODO join with register as Pairs ?
     val retvalRegisters: List<RegisterOrStatusflag>,
     val inline: Boolean,
     position: Position
@@ -28,6 +29,14 @@ class PtSub(
     override fun printProperties() {
         print(name)
     }
+
+    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")
+    }
 }
 
 

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

@@ -20,5 +20,8 @@ class CompilationOptions(val output: OutputType,
                          var asmQuiet: Boolean = false,
                          var asmListfile: Boolean = false,
                          var experimentalCodegen: Boolean = false,
-                         var outputDir: Path = Path("")
+                         var keepIR: Boolean = false,
+                         var evalStackBaseAddress: UInt? = null,
+                         var outputDir: Path = Path(""),
+                         var symbolDefs: Map<String, String> = emptyMap()
 )

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

@@ -6,12 +6,14 @@ enum class DataType {
     UWORD,              // pass by value
     WORD,               // pass by value
     FLOAT,              // pass by value
+    BOOL,               // pass by value
     STR,                // pass by reference
     ARRAY_UB,           // pass by reference
     ARRAY_B,            // pass by reference
     ARRAY_UW,           // pass by reference
     ARRAY_W,            // pass by reference
     ARRAY_F,            // pass by reference
+    ARRAY_BOOL,         // pass by reference
     UNDEFINED;
 
     /**
@@ -19,11 +21,12 @@ enum class DataType {
      */
     infix fun isAssignableTo(targetType: DataType) =
         when(this) {
-            UBYTE -> targetType.oneOf(UBYTE, WORD, UWORD, FLOAT)
+            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)
-            FLOAT -> targetType == FLOAT
+            FLOAT -> targetType.oneOf(FLOAT)
             STR -> targetType.oneOf(STR, UWORD)
             in ArrayDatatypes -> targetType == this
             else -> false
@@ -53,13 +56,7 @@ enum class DataType {
 enum class CpuRegister {
     A,
     X,
-    Y;
-
-    fun asRegisterOrPair(): RegisterOrPair = when(this) {
-        A -> RegisterOrPair.A
-        X -> RegisterOrPair.X
-        Y -> RegisterOrPair.Y
-    }
+    Y
 }
 
 enum class RegisterOrPair {
@@ -115,19 +112,20 @@ enum class BranchCondition {
 }
 
 
-val ByteDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE)
+val ByteDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE, DataType.BOOL)
 val WordDatatypes = arrayOf(DataType.UWORD, DataType.WORD)
-val IntegerDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD)
-val NumericDatatypes = arrayOf(DataType.UBYTE, DataType.BYTE, DataType.UWORD, DataType.WORD, DataType.FLOAT)
+val 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 IntegerArrayDatatypes = arrayOf(DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W)
-val ArrayDatatypes = arrayOf(DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W, DataType.ARRAY_F)
+val ArrayDatatypes = arrayOf(DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W, DataType.ARRAY_F, DataType.ARRAY_BOOL)
 val StringlyDatatypes = arrayOf(DataType.STR, DataType.ARRAY_UB, DataType.ARRAY_B, DataType.UWORD)
 val IterableDatatypes = arrayOf(
     DataType.STR,
     DataType.ARRAY_UB, DataType.ARRAY_B,
     DataType.ARRAY_UW, DataType.ARRAY_W,
-    DataType.ARRAY_F
+    DataType.ARRAY_F, DataType.ARRAY_BOOL
 )
 val PassByValueDatatypes = NumericDatatypes
 val PassByReferenceDatatypes = IterableDatatypes
@@ -137,14 +135,16 @@ val ArrayToElementTypes = mapOf(
     DataType.ARRAY_UB to DataType.UBYTE,
     DataType.ARRAY_W to DataType.WORD,
     DataType.ARRAY_UW to DataType.UWORD,
-    DataType.ARRAY_F to DataType.FLOAT
+    DataType.ARRAY_F to DataType.FLOAT,
+    DataType.ARRAY_BOOL to DataType.BOOL
 )
 val ElementToArrayTypes = mapOf(
     DataType.BYTE to DataType.ARRAY_B,
     DataType.UBYTE to DataType.ARRAY_UB,
     DataType.WORD to DataType.ARRAY_W,
     DataType.UWORD to DataType.ARRAY_UW,
-    DataType.FLOAT to DataType.ARRAY_F
+    DataType.FLOAT to DataType.ARRAY_F,
+    DataType.BOOL to DataType.ARRAY_BOOL
 )
 val Cx16VirtualRegisters = arrayOf(
     RegisterOrPair.R0, RegisterOrPair.R1, RegisterOrPair.R2, RegisterOrPair.R3,

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

@@ -3,11 +3,6 @@ package prog8.code.core
 import java.nio.file.Path
 
 
-interface IMachineFloat {
-    fun toDouble(): Double
-    fun makeFloatFillAsm(): String
-}
-
 enum class CpuType {
     CPU6502,
     CPU65c02,
@@ -18,8 +13,8 @@ interface IMachineDefinition {
     val FLOAT_MAX_NEGATIVE: Double
     val FLOAT_MAX_POSITIVE: Double
     val FLOAT_MEM_SIZE: Int
-    val ESTACK_LO: UInt
-    val ESTACK_HI: UInt
+    var ESTACK_LO: UInt
+    var ESTACK_HI: UInt
     val PROGRAM_LOAD_ADDRESS : UInt
 
     val opcodeNames: Set<String>
@@ -27,9 +22,14 @@ interface IMachineDefinition {
     val cpu: CpuType
 
     fun initializeZeropage(compilerOptions: CompilationOptions)
-    fun getFloat(num: Number): IMachineFloat
+    fun getFloatAsmBytes(num: Number): String
 
     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
+    }
 }

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

@@ -1,10 +1,11 @@
 package prog8.code.core
 
-val AssociativeOperators = setOf("+", "*", "&", "|", "^", "or", "and", "xor", "==", "!=")
+val AssociativeOperators = setOf("+", "*", "&", "|", "^", "==", "!=")
 val ComparisonOperators = setOf("==", "!=", "<", ">", "<=", ">=")
-val AugmentAssignmentOperators = setOf("+", "-", "/", "*", "&", "|", "^", "<<", ">>", "%", "and", "or", "xor")
 val LogicalOperators = setOf("and", "or", "xor", "not")
-val BitwiseOperators = setOf("&", "|", "^")
+val AugmentAssignmentOperators = setOf("+", "-", "/", "*", "&", "|", "^", "<<", ">>", "%", "and", "or", "xor")
+val BitwiseOperators = setOf("&", "|", "^", "~")
+// val InvalidOperatorsForBoolean = setOf("+", "-", "*", "/", "%", "<<", ">>") + BitwiseOperators
 
 fun invertedComparisonOperator(operator: String) =
     when (operator) {

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

@@ -1,16 +1,22 @@
 package prog8.code.core
 
+import java.nio.file.InvalidPathException
 import kotlin.io.path.Path
 import kotlin.io.path.absolute
 
 data class Position(val file: String, val line: Int, val startCol: Int, val endCol: Int) {
     override fun toString(): String = "[$file: line $line col ${startCol+1}-${endCol+1}]"
     fun toClickableStr(): String {
-        val path = Path(file).absolute().normalize()
-        return "file://$path:$line:$startCol:"
+        return try {
+            val path = Path(file).absolute().normalize().toString()
+            "file://$path:$line:$startCol:"
+        } catch(x: InvalidPathException) {
+            // this can occur on Windows when the source origin contains "invalid" characters such as ':'
+            "file://$file:$line:$startCol:"
+        }
     }
 
     companion object {
-        val DUMMY = Position("<dummy>", 0, 0, 0)
+        val DUMMY = Position("~dummy~", 0, 0, 0)
     }
 }

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

@@ -34,7 +34,7 @@ sealed class SourceCode {
      * Where this [SourceCode] instance came from.
      * This can be one of the following:
      * * a normal string representation of a [java.nio.file.Path], if it originates from a file (see [File])
-     * * `$stringSourcePrefix44c56085>` if was created via [String]
+     * * `string:44c56085` if was created via [String]
      * * `library:/x/y/z.ext` if it is a library file that was loaded from resources (see [Resource])
      */
     abstract val origin: String
@@ -55,7 +55,7 @@ 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 stringSourcePrefix = "string:"
         val curdir: Path = Path(".").toAbsolutePath()
         fun relative(path: Path): Path = curdir.relativize(path.toAbsolutePath())
         fun isRegularFilesystemPath(pathString: String) =
@@ -64,12 +64,12 @@ sealed class SourceCode {
 
     /**
      * Turn a plain String into a [SourceCode] object.
-     * [origin] will be something like `$stringSourcePrefix44c56085>`.
+     * [origin] will be something like `string:44c56085`.
      */
     class Text(override val text: String): SourceCode() {
         override val isFromResources = false
         override val isFromFilesystem = false
-        override val origin = "$stringSourcePrefix${System.identityHashCode(text).toString(16)}>"
+        override val origin = "$stringSourcePrefix${System.identityHashCode(text).toString(16)}"
         override val name = "<unnamed-text>"
     }
 
@@ -106,7 +106,7 @@ sealed class SourceCode {
      * [origin]: `library:/x/y/z.p8` for a given `pathString` of "x/y/z.p8"
      */
     class Resource(pathString: String): SourceCode() {
-        private val normalized = "/" + Path.of(pathString).normalize().toMutableList().joinToString("/")
+        private val normalized = "/" + Path(pathString).normalize().toMutableList().joinToString("/")
 
         override val isFromResources = true
         override val isFromFilesystem = false
@@ -125,7 +125,7 @@ sealed class SourceCode {
             }
             val stream = object {}.javaClass.getResourceAsStream(normalized)
             text = stream!!.reader().use { it.readText() }
-            name = Path.of(pathString).toFile().nameWithoutExtension
+            name = Path(pathString).toFile().nameWithoutExtension
         }
     }
 

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

@@ -117,4 +117,6 @@ abstract class Zeropage(protected val options: CompilationOptions) {
         require(size>0)
         return free.containsAll((address until address+size.toUInt()).toList())
     }
+
+    abstract fun allocateCx16VirtualRegisters()
 }

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

@@ -15,12 +15,12 @@ class AtariMachineDefinition: IMachineDefinition {
     override val PROGRAM_LOAD_ADDRESS = 0x2000u
 
     // the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
-    override val ESTACK_LO = 0x1a00u     //  $1a00-$1aff inclusive      // TODO
-    override val ESTACK_HI = 0x1b00u     //  $1b00-$1bff inclusive      // TODO
+    override var ESTACK_LO = 0x1a00u     //  $1a00-$1aff inclusive      // TODO
+    override var ESTACK_HI = 0x1b00u     //  $1b00-$1bff inclusive      // TODO
 
     override lateinit var zeropage: Zeropage
 
-    override fun getFloat(num: Number) = TODO("float from number")
+    override fun getFloatAsmBytes(num: Number) = TODO("float asm bytes from number")
 
     override fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
         return if (compilerOptions.output == OutputType.XEX)

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

@@ -12,7 +12,6 @@ class AtariZeropage(options: CompilationOptions) : Zeropage(options) {
     override val SCRATCH_W1 = 0xcdu      // temp storage 1 for a word  $cd+$ce
     override val SCRATCH_W2 = 0xcfu      // temp storage 2 for a word  $cf+$d0        TODO is $d0 okay to use?
 
-
     init {
         if (options.floats && options.zeropage !in arrayOf(
                 ZeropageType.FLOATSAFE,
@@ -40,6 +39,14 @@ class AtariZeropage(options: CompilationOptions) : Zeropage(options) {
             }
         }
 
+        val distictFree = free.distinct()
+        free.clear()
+        free.addAll(distictFree)
+
         removeReservedFromFreePool()
     }
+
+    override fun allocateCx16VirtualRegisters() {
+        TODO("Not known if atari can put the virtual regs in ZP")
+    }
 }

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

@@ -16,12 +16,12 @@ class C128MachineDefinition: IMachineDefinition {
     override val PROGRAM_LOAD_ADDRESS = 0x1c01u
 
     // the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
-    override val ESTACK_LO = 0x1a00u     //  $1a00-$1aff inclusive
-    override val ESTACK_HI = 0x1b00u     //  $1b00-$1bff inclusive
+    override var ESTACK_LO = 0x1a00u     //  $1a00-$1aff inclusive
+    override var ESTACK_HI = 0x1b00u     //  $1b00-$1bff inclusive
 
     override lateinit var zeropage: Zeropage
 
-    override fun getFloat(num: Number) = Mflpt5.fromNumber(num)
+    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)

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

@@ -38,6 +38,14 @@ class C128Zeropage(options: CompilationOptions) : Zeropage(options) {
             }
         }
 
+        val distictFree = free.distinct()
+        free.clear()
+        free.addAll(distictFree)
+
         removeReservedFromFreePool()
     }
+
+    override fun allocateCx16VirtualRegisters() {
+        TODO("Not known if C128 can put the virtual regs in ZP")
+    }
 }

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

@@ -16,12 +16,12 @@ class C64MachineDefinition: IMachineDefinition {
     override val PROGRAM_LOAD_ADDRESS = 0x0801u
 
     // the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
-    override val ESTACK_LO = 0xce00u     //  $ce00-$ceff inclusive
-    override val ESTACK_HI = 0xcf00u     //  $ce00-$ceff inclusive
+    override var ESTACK_LO = 0xce00u     //  $ce00-$ceff inclusive
+    override var ESTACK_HI = 0xcf00u     //  $ce00-$ceff inclusive
 
     override lateinit var zeropage: Zeropage
 
-    override fun getFloat(num: Number) = Mflpt5.fromNumber(num)
+    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)

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

@@ -1,9 +1,6 @@
 package prog8.code.target.c64
 
-import prog8.code.core.CompilationOptions
-import prog8.code.core.InternalCompilerException
-import prog8.code.core.Zeropage
-import prog8.code.core.ZeropageType
+import prog8.code.core.*
 
 
 class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
@@ -29,10 +26,9 @@ class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
         } else {
             if (options.zeropage == ZeropageType.KERNALSAFE || options.zeropage == ZeropageType.FLOATSAFE) {
                 free.addAll(listOf(
-                        0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
-                        0x16, 0x17, 0x18, 0x19, 0x1a,
-                        0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21,
-                        0x22, 0x23, 0x24, 0x25,
+                        0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+                        0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+                        0x20, 0x21, 0x22, 0x23, 0x24, 0x25,
                         0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46,
                         0x47, 0x48, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x51, 0x52, 0x53,
                         0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
@@ -48,8 +44,8 @@ class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
             if (options.zeropage == ZeropageType.FLOATSAFE) {
                 // remove the zeropage locations used for floating point operations from the free list
                 free.removeAll(listOf(
-                        0x22, 0x23, 0x24, 0x25,
-                        0x10, 0x11, 0x12, 0x26, 0x27, 0x28, 0x29, 0x2a,
+                        0x03, 0x04, 0x10, 0x11, 0x12,
+                        0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a,
                         0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
                         0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
                         0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72,
@@ -60,7 +56,7 @@ class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
             if(options.zeropage!= ZeropageType.DONTUSE) {
                 // add the free Zp addresses
                 // these are valid for the C-64 but allow BASIC to keep running fully *as long as you don't use tape I/O*
-                free.addAll(listOf(0x04, 0x05, 0x06, 0x0a, 0x0e,
+                free.addAll(listOf(0x02, 0x03, 0x04, 0x05, 0x06, 0x0a, 0x0e,
                         0x92, 0x96, 0x9b, 0x9c, 0x9e, 0x9f, 0xa5, 0xa6,
                         0xb0, 0xb1, 0xbe, 0xbf, 0xf9).map{it.toUInt()})
             } else {
@@ -69,6 +65,32 @@ class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
             }
         }
 
+        val distictFree = free.distinct()
+        free.clear()
+        free.addAll(distictFree)
+
         removeReservedFromFreePool()
+
+        if(options.zeropage==ZeropageType.FULL || options.zeropage==ZeropageType.KERNALSAFE) {
+            // in these cases there is enough space on the zero page to stick the cx16 virtual registers in there as well.
+            allocateCx16VirtualRegisters()
+        }
+    }
+
+    override fun allocateCx16VirtualRegisters() {
+        // Note: the 16 virtual registers R0-R15 are not regular allocated variables, they're *memory mapped* elsewhere to fixed addresses.
+        // However, to be able for the compiler to "see" them as zero page variables, we have to register them here as well.
+        // This is important because the compiler sometimes treats ZP variables more efficiently (for example if it's a pointer)
+        // The base addres is $04.  Unfortunately it cannot be the same as on the Commander X16 ($02).
+        for(reg in 0..15) {
+            allocatedVariables[listOf("cx16", "r${reg}")]   = ZpAllocation((4+reg*2).toUInt(), DataType.UWORD, 2)       // cx16.r0 .. cx16.r15
+            allocatedVariables[listOf("cx16", "r${reg}s")]  = ZpAllocation((4+reg*2).toUInt(), DataType.WORD, 2)        // cx16.r0s .. cx16.r15s
+            allocatedVariables[listOf("cx16", "r${reg}L")]  = ZpAllocation((4+reg*2).toUInt(), DataType.UBYTE, 1)       // cx16.r0L .. cx16.r15L
+            allocatedVariables[listOf("cx16", "r${reg}H")]  = ZpAllocation((5+reg*2).toUInt(), DataType.UBYTE, 1)       // cx16.r0H .. cx16.r15H
+            allocatedVariables[listOf("cx16", "r${reg}sL")] = ZpAllocation((4+reg*2).toUInt(), DataType.BYTE, 1)        // cx16.r0sL .. cx16.r15sL
+            allocatedVariables[listOf("cx16", "r${reg}sH")] = ZpAllocation((5+reg*2).toUInt(), DataType.BYTE, 1)        // cx16.r0sH .. cx16.r15sH
+            free.remove((4+reg*2).toUInt())
+            free.remove((5+reg*2).toUInt())
+        }
     }
 }

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

@@ -1,12 +1,11 @@
 package prog8.code.target.cbm
 
-import prog8.code.core.IMachineFloat
 import prog8.code.core.InternalCompilerException
 import kotlin.math.absoluteValue
 import kotlin.math.pow
 
 
-data class Mflpt5(val b0: UByte, val b1: UByte, val b2: UByte, val b3: UByte, val b4: UByte): IMachineFloat {
+data class Mflpt5(val b0: UByte, val b1: UByte, val b2: UByte, val b3: UByte, val b4: UByte) {
 
     companion object {
         const val FLOAT_MAX_POSITIVE = 1.7014118345e+38         // bytes: 255,127,255,255,255
@@ -58,7 +57,7 @@ data class Mflpt5(val b0: UByte, val b1: UByte, val b2: UByte, val b3: UByte, va
         }
     }
 
-    override fun toDouble(): Double {
+    fun toDouble(): Double {
         if (this == zero) return 0.0
         val exp = b0.toInt() - 128
         val sign = (b1.toInt() and 0x80) > 0
@@ -67,7 +66,7 @@ data class Mflpt5(val b0: UByte, val b1: UByte, val b2: UByte, val b3: UByte, va
         return if (sign) -result else result
     }
 
-    override fun makeFloatFillAsm(): String {
+    fun makeFloatFillAsm(): String {
         val b0 = "$" + b0.toString(16).padStart(2, '0')
         val b1 = "$" + b1.toString(16).padStart(2, '0')
         val b2 = "$" + b2.toString(16).padStart(2, '0')

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

@@ -15,12 +15,12 @@ class CX16MachineDefinition: IMachineDefinition {
     override val PROGRAM_LOAD_ADDRESS = 0x0801u
 
     // the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
-    override val ESTACK_LO = 0x0400u        //  $0400-$04ff inclusive
-    override val ESTACK_HI = 0x0500u        //  $0500-$05ff inclusive
+    override var ESTACK_LO = 0x0400u        //  $0400-$04ff inclusive
+    override var ESTACK_HI = 0x0500u        //  $0500-$05ff inclusive
 
     override lateinit var zeropage: Zeropage
 
-    override fun getFloat(num: Number) = Mflpt5.fromNumber(num)
+    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")

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

@@ -43,18 +43,27 @@ class CX16Zeropage(options: CompilationOptions) : Zeropage(options) {
                 else -> throw InternalCompilerException("for this machine target, zero page type 'floatsafe' is not available. ${options.zeropage}")
             }
 
+            val distictFree = free.distinct()
+            free.clear()
+            free.addAll(distictFree)
+
             removeReservedFromFreePool()
 
-            // note: the 16 virtual registers R0-R15 are not regular allocated variables, they're *memory mapped* elsewhere to fixed addresses.
-            // however, to be able for the compiler to "see" them as zero page variables, we have to register them here as well.
-            for(reg in 0..15) {
-                allocatedVariables[listOf("cx16", "r${reg}")]   = ZpAllocation((2+reg*2).toUInt(), DataType.UWORD, 2)        // cx16.r0 .. cx16.r15
-                allocatedVariables[listOf("cx16", "r${reg}s")]  = ZpAllocation((2+reg*2).toUInt(), DataType.WORD, 2)        // cx16.r0s .. cx16.r15s
-                allocatedVariables[listOf("cx16", "r${reg}L")]  = ZpAllocation((2+reg*2).toUInt(), DataType.UBYTE, 1)       // cx16.r0L .. cx16.r15L
-                allocatedVariables[listOf("cx16", "r${reg}H")]  = ZpAllocation((3+reg*2).toUInt(), DataType.UBYTE, 1)       // cx16.r0H .. cx16.r15H
-                allocatedVariables[listOf("cx16", "r${reg}sL")] = ZpAllocation((2+reg*2).toUInt(), DataType.BYTE, 1)       // cx16.r0sL .. cx16.r15sL
-                allocatedVariables[listOf("cx16", "r${reg}sH")] = ZpAllocation((3+reg*2).toUInt(), DataType.BYTE, 1)       // cx16.r0sH .. cx16.r15sH
-            }
+            allocateCx16VirtualRegisters()
+        }
+    }
+
+    override fun allocateCx16VirtualRegisters() {
+        // Note: the 16 virtual registers R0-R15 are not regular allocated variables, they're *memory mapped* elsewhere to fixed addresses.
+        // However, to be able for the compiler to "see" them as zero page variables, we have to register them here as well.
+        // This is important because the compiler sometimes treats ZP variables more efficiently (for example if it's a pointer)
+        for(reg in 0..15) {
+            allocatedVariables[listOf("cx16", "r${reg}")]   = ZpAllocation((2+reg*2).toUInt(), DataType.UWORD, 2)       // cx16.r0 .. cx16.r15
+            allocatedVariables[listOf("cx16", "r${reg}s")]  = ZpAllocation((2+reg*2).toUInt(), DataType.WORD, 2)        // cx16.r0s .. cx16.r15s
+            allocatedVariables[listOf("cx16", "r${reg}L")]  = ZpAllocation((2+reg*2).toUInt(), DataType.UBYTE, 1)       // cx16.r0L .. cx16.r15L
+            allocatedVariables[listOf("cx16", "r${reg}H")]  = ZpAllocation((3+reg*2).toUInt(), DataType.UBYTE, 1)       // cx16.r0H .. cx16.r15H
+            allocatedVariables[listOf("cx16", "r${reg}sL")] = ZpAllocation((2+reg*2).toUInt(), DataType.BYTE, 1)        // cx16.r0sL .. cx16.r15sL
+            allocatedVariables[listOf("cx16", "r${reg}sH")] = ZpAllocation((3+reg*2).toUInt(), DataType.BYTE, 1)        // cx16.r0sH .. cx16.r15sH
         }
     }
 }

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

@@ -6,6 +6,8 @@ import prog8.code.core.IMachineDefinition
 import prog8.code.core.Zeropage
 import java.io.File
 import java.nio.file.Path
+import kotlin.io.path.name
+import kotlin.io.path.readText
 
 
 class VirtualMachineDefinition: IMachineDefinition {
@@ -17,12 +19,12 @@ class VirtualMachineDefinition: IMachineDefinition {
     override val FLOAT_MEM_SIZE = 4             // 32-bits floating point
     override val PROGRAM_LOAD_ADDRESS = 0u      // not actually used
 
-    override val ESTACK_LO = 0u                 // not actually used
-    override val ESTACK_HI = 0u                 // not actually used
+    override var ESTACK_LO = 0u                 // not actually used
+    override var ESTACK_HI = 0u                 // not actually used
 
     override lateinit var zeropage: Zeropage     // not actually used
 
-    override fun getFloat(num: Number) = TODO("float from number")
+    override fun getFloatAsmBytes(num: Number) = TODO("float asm bytes from number")
 
     override fun importLibs(compilerOptions: CompilationOptions, compilationTargetName: String): List<String> {
         return listOf("syslib")
@@ -30,10 +32,17 @@ class VirtualMachineDefinition: IMachineDefinition {
 
     override fun launchEmulator(selectedEmulator: Int, programNameWithPath: Path) {
         println("\nStarting Virtual Machine...")
-        // to not have external module dependencies we launch the virtual machine via reflection
+        // to not have external module dependencies in our own module, we launch the virtual machine via reflection
         val vm = Class.forName("prog8.vm.VmRunner").getDeclaredConstructor().newInstance() as IVirtualMachineRunner
-        val source = File("$programNameWithPath.p8virt").readText()
-        vm.runProgram(source, true)
+        val filename = programNameWithPath.name
+        if(filename.endsWith(".p8virt")) {
+            vm.runProgram(programNameWithPath.readText())
+        } else if(File("$filename.p8virt").isFile) {
+            val source = File("$filename.p8virt").readText()
+            vm.runProgram(source)
+        }
+        else
+            throw IllegalArgumentException("vm can only run .p8virt or .p8ir files")
     }
 
     override fun isIOAddress(address: UInt): Boolean = false
@@ -44,5 +53,5 @@ class VirtualMachineDefinition: IMachineDefinition {
 }
 
 interface IVirtualMachineRunner {
-    fun runProgram(source: String, throttle: Boolean)
+    fun runProgram(source: String)
 }

codeGenCpu6502/build.gradle

@@ -24,12 +24,11 @@ compileTestKotlin {
 }
 
 dependencies {
-    implementation project(':codeAst')
     implementation project(':codeCore')
     implementation project(':compilerAst')
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
     // implementation "org.jetbrains.kotlin:kotlin-reflect"
-    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.14"
+    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.16"
 
 }
 

codeGenCpu6502/codeGenCpu6502.iml

@@ -9,7 +9,6 @@
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="library" name="KotlinJavaRuntime" level="project" />
-    <orderEntry type="module" module-name="codeAst" />
     <orderEntry type="module" module-name="codeCore" />
     <orderEntry type="module" module-name="compilerAst" />
     <orderEntry type="library" name="michael.bull.kotlin.result.jvm" level="project" />

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

@@ -8,6 +8,7 @@ import prog8.ast.Program
 import prog8.ast.base.FatalAstException
 import prog8.ast.expressions.*
 import prog8.ast.statements.*
+import prog8.code.StMemorySlab
 import prog8.code.SymbolTable
 import prog8.code.core.*
 import prog8.codegen.cpu6502.assignment.*
@@ -18,7 +19,6 @@ import kotlin.io.path.Path
 import kotlin.io.path.writeLines
 
 
-internal const val generatedLabelPrefix = "prog8_label_"
 internal const val subroutineFloatEvalResultVar1 = "prog8_float_eval_result1"
 internal const val subroutineFloatEvalResultVar2 = "prog8_float_eval_result2"
 
@@ -73,19 +73,12 @@ class AsmGen(internal val program: Program,
 
     internal fun isTargetCpu(cpu: CpuType) = options.compTarget.machine.cpu == cpu
 
-    private var generatedLabelSequenceNumber: Int = 0
-
-    internal fun makeLabel(postfix: String): String {
-        generatedLabelSequenceNumber++
-        return "${generatedLabelPrefix}${generatedLabelSequenceNumber}_$postfix"
-    }
-
     internal fun outputSourceLine(node: Node) {
         out(" ;\tsrc line: ${node.position.file}:${node.position.line}")
     }
 
     internal fun out(str: String, splitlines: Boolean = true) {
-        val fragment = (if(" | " in str) str.replace("|", "\n") else str).trim('\n')
+        val fragment = (if(splitlines && " | " in str) str.replace("|", "\n") else str).trim('\n')
         if (splitlines) {
             for (line in fragment.splitToSequence('\n')) {
                 val trimmed = if (line.startsWith(' ')) "\t" + line.trim() else line
@@ -319,13 +312,12 @@ class AsmGen(internal val program: Program,
             is Subroutine -> programGen.translateSubroutine(stmt)
             is InlineAssembly -> translate(stmt)
             is BuiltinFunctionCallStatement -> builtinFunctionsAsmGen.translateFunctioncallStatement(stmt)
-            is FunctionCallStatement -> functioncallAsmGen.translateFunctionCallStatement(stmt)         // TODO try to remove this last usage of FunctionCallStatement node in the codegen.
+            is FunctionCallStatement -> functioncallAsmGen.translateFunctionCallStatement(stmt)
             is Assignment -> assignmentAsmGen.translate(stmt)
             is Jump -> {
                 val (asmLabel, indirect) = getJumpTarget(stmt)
                 jmp(asmLabel, indirect)
             }
-            is GoSub -> translate(stmt)
             is PostIncrDecr -> postincrdecrAsmGen.translate(stmt)
             is Label -> translate(stmt)
             is ConditionalBranch -> translate(stmt)
@@ -334,7 +326,6 @@ class AsmGen(internal val program: Program,
             is RepeatLoop -> translate(stmt)
             is When -> translate(stmt)
             is AnonymousScope -> translate(stmt)
-            is Pipe -> translatePipeExpression(stmt.source, stmt.segments, stmt, isStatement = true, pushResultOnEstack = false)
             is VarDecl -> { /* do nothing; variables are handled elsewhere */ }
             is BuiltinFunctionPlaceholder -> throw AssemblyError("builtin function should not have placeholder anymore")
             is UntilLoop -> throw AssemblyError("do..until should have been converted to jumps")
@@ -444,27 +435,15 @@ class AsmGen(internal val program: Program,
     internal fun translateBuiltinFunctionCallExpression(bfc: BuiltinFunctionCall, resultToStack: Boolean, resultRegister: RegisterOrPair?) =
             builtinFunctionsAsmGen.translateFunctioncallExpression(bfc, resultToStack, resultRegister)
 
-    private fun translateBuiltinFunctionCallExpression(bfc: IFunctionCall, firstArg: AsmAssignSource, scope: Subroutine): DataType =
-            builtinFunctionsAsmGen.translateFunctionCallWithFirstArg(bfc, firstArg, false, scope)
-
-    private fun translateBuiltinFunctionCallStatement(bfc: IFunctionCall, firstArg: AsmAssignSource, scope: Subroutine) =
-            builtinFunctionsAsmGen.translateFunctionCallWithFirstArg(bfc, firstArg, true, scope)
-
     internal fun translateFunctionCall(functionCallExpr: FunctionCallExpression, isExpression: Boolean) =
             functioncallAsmGen.translateFunctionCall(functionCallExpr, isExpression)
 
     internal fun saveXbeforeCall(functionCall: IFunctionCall)  =
             functioncallAsmGen.saveXbeforeCall(functionCall)
 
-    internal fun saveXbeforeCall(gosub: GoSub)  =
-            functioncallAsmGen.saveXbeforeCall(gosub)
-
     internal fun restoreXafterCall(functionCall: IFunctionCall) =
             functioncallAsmGen.restoreXafterCall(functionCall)
 
-    internal fun restoreXafterCall(gosub: GoSub) =
-            functioncallAsmGen.restoreXafterCall(gosub)
-
     internal fun translateNormalAssignment(assign: AsmAssignment) =
             assignmentAsmGen.translateNormalAssignment(assign)
 
@@ -550,7 +529,7 @@ class AsmGen(internal val program: Program,
             if(jump is Jump) {
                 translateCompareAndJumpIfTrue(booleanCondition, jump)
             } else {
-                val endLabel = makeLabel("if_end")
+                val endLabel = program.makeLabel("if_end")
                 translateCompareAndJumpIfFalse(booleanCondition, endLabel)
                 translate(stmt.truepart)
                 out(endLabel)
@@ -558,8 +537,8 @@ class AsmGen(internal val program: Program,
         }
         else {
             // both true and else parts
-            val elseLabel = makeLabel("if_else")
-            val endLabel = makeLabel("if_end")
+            val elseLabel = program.makeLabel("if_else")
+            val endLabel = program.makeLabel("if_end")
             translateCompareAndJumpIfFalse(booleanCondition, elseLabel)
             translate(stmt.truepart)
             jmp(endLabel)
@@ -575,7 +554,7 @@ class AsmGen(internal val program: Program,
     }
 
     private fun translate(stmt: RepeatLoop) {
-        val endLabel = makeLabel("repeatend")
+        val endLabel = program.makeLabel("repeatend")
         loopEndLabels.push(endLabel)
 
         when (stmt.iterations) {
@@ -628,7 +607,7 @@ class AsmGen(internal val program: Program,
 
     private fun repeatWordCount(count: Int, stmt: RepeatLoop) {
         require(count in 257..65535)
-        val repeatLabel = makeLabel("repeat")
+        val repeatLabel = program.makeLabel("repeat")
         if(isTargetCpu(CpuType.CPU65c02)) {
             val counterVar = createRepeatCounterVar(DataType.UWORD, true, stmt)
             out("""
@@ -669,7 +648,7 @@ $repeatLabel""")
     private fun repeatWordCountInAY(endLabel: String, stmt: RepeatLoop) {
         // note: A/Y must have been loaded with the number of iterations!
         // no need to explicitly test for 0 iterations as this is done in the countdown logic below
-        val repeatLabel = makeLabel("repeat")
+        val repeatLabel = program.makeLabel("repeat")
         val counterVar = createRepeatCounterVar(DataType.UWORD, false, stmt)
         out("""
                 sta  $counterVar
@@ -690,7 +669,7 @@ $repeatLabel    lda  $counterVar
 
     private fun repeatByteCount(count: Int, stmt: RepeatLoop) {
         require(count in 2..256)
-        val repeatLabel = makeLabel("repeat")
+        val repeatLabel = program.makeLabel("repeat")
         if(isTargetCpu(CpuType.CPU65c02)) {
             val counterVar = createRepeatCounterVar(DataType.UBYTE, true, stmt)
             out("  lda  #${count and 255} |  sta  $counterVar")
@@ -708,7 +687,7 @@ $repeatLabel    lda  $counterVar
 
     private fun repeatCountInY(stmt: RepeatLoop, endLabel: String) {
         // note: Y must just have been loaded with the (variable) number of loops to be performed!
-        val repeatLabel = makeLabel("repeat")
+        val repeatLabel = program.makeLabel("repeat")
         if(isTargetCpu(CpuType.CPU65c02)) {
             val counterVar = createRepeatCounterVar(DataType.UBYTE, true, stmt)
             out("  beq  $endLabel |  sty  $counterVar")
@@ -745,7 +724,7 @@ $repeatLabel    lda  $counterVar
             }
         }
 
-        val counterVar = makeLabel("counter")
+        val counterVar = program.makeLabel("counter")
         when(dt) {
             DataType.UBYTE, DataType.UWORD -> {
                 val result = zeropage.allocate(listOf(counterVar), dt, null, stmt.position, errors)
@@ -760,7 +739,7 @@ $repeatLabel    lda  $counterVar
     }
 
     private fun translate(stmt: When) {
-        val endLabel = makeLabel("choice_end")
+        val endLabel = program.makeLabel("choice_end")
         val choiceBlocks = mutableListOf<Pair<String, AnonymousScope>>()
         val conditionDt = stmt.condition.inferType(program)
         if(!conditionDt.isKnown)
@@ -771,7 +750,7 @@ $repeatLabel    lda  $counterVar
             assignExpressionToRegister(stmt.condition, RegisterOrPair.AY)
 
         for(choice in stmt.choices) {
-            val choiceLabel = makeLabel("choice")
+            val choiceLabel = program.makeLabel("choice")
             if(choice.values==null) {
                 // the else choice
                 translate(choice.statements)
@@ -835,14 +814,14 @@ $repeatLabel    lda  $counterVar
         } else {
             if(stmt.elsepart.isEmpty()) {
                 val instruction = branchInstruction(stmt.condition, true)
-                val elseLabel = makeLabel("branch_else")
+                val elseLabel = program.makeLabel("branch_else")
                 out("  $instruction  $elseLabel")
                 translate(stmt.truepart)
                 out(elseLabel)
             } else {
                 val instruction = branchInstruction(stmt.condition, true)
-                val elseLabel = makeLabel("branch_else")
-                val endLabel = makeLabel("branch_end")
+                val elseLabel = program.makeLabel("branch_else")
+                val endLabel = program.makeLabel("branch_end")
                 out("  $instruction  $elseLabel")
                 translate(stmt.truepart)
                 jmp(endLabel)
@@ -887,18 +866,6 @@ $repeatLabel    lda  $counterVar
         }
     }
 
-    private fun translate(gosub: GoSub) {
-        val tgt = gosub.identifier.targetSubroutine(program)
-        if(tgt!=null && tgt.isAsmSubroutine) {
-            // no need to rescue X , this has been taken care of already
-            out("  jsr  ${getJumpTarget(gosub)}")
-        } else {
-            saveXbeforeCall(gosub)
-            out("  jsr  ${getJumpTarget(gosub)}")
-            restoreXafterCall(gosub)
-        }
-    }
-
     private fun getJumpTarget(jump: Jump): Pair<String, Boolean> {
         val ident = jump.identifier
         val label = jump.generatedLabel
@@ -918,8 +885,6 @@ $repeatLabel    lda  $counterVar
         }
     }
 
-    private fun getJumpTarget(gosub: GoSub): String = asmSymbolName(gosub.identifier)
-
     private fun translate(ret: Return, withRts: Boolean=true) {
         ret.value?.let { returnvalue ->
             val sub = ret.definingSubroutine!!
@@ -1180,14 +1145,14 @@ $repeatLabel    lda  $counterVar
             return testVariableZeroAndJump(left, dt, operator, jumpIfFalseLabel)
 
         when(dt) {
-            DataType.UBYTE, DataType.UWORD -> {
+            DataType.BOOL, DataType.UBYTE, DataType.UWORD -> {
                 if(operator=="<") {
                     out("  jmp  $jumpIfFalseLabel")
                     return
                 } else if(operator==">=") {
                     return
                 }
-                if(dt==DataType.UBYTE) {
+                if(dt==DataType.UBYTE || dt==DataType.BOOL) {
                     assignExpressionToRegister(left, RegisterOrPair.A, false)
                     if (left is IFunctionCall && !left.isSimple)
                         out("  cmp  #0")
@@ -1267,7 +1232,7 @@ $repeatLabel    lda  $counterVar
         // optimized code if the expression is just an identifier (variable)
         val varname = asmVariableName(variable)
         when(dt) {
-            DataType.UBYTE -> when(operator) {
+            DataType.UBYTE, DataType.BOOL -> when(operator) {
                 "==" -> out("  lda  $varname |  bne  $jumpIfFalseLabel")
                 "!=" -> out("  lda  $varname |  beq  $jumpIfFalseLabel")
                 ">"  -> out("  lda  $varname |  beq  $jumpIfFalseLabel")
@@ -2812,123 +2777,6 @@ $repeatLabel    lda  $counterVar
         }
     }
 
-    internal fun translatePipeExpression(source: Expression, segments: List<Expression>, scope: Node, isStatement: Boolean, pushResultOnEstack: Boolean) {
-
-        // TODO more efficient code generation to avoid needless assignments to the temp var
-
-        // the source: an expression (could be anything) producing a value.
-        // one or more segment expressions, all are a IFunctionCall node, and LACKING the implicit first argument.
-        // when 'isStatement'=true, the last segment expression should be treated as a funcion call statement (discarding any result value if there is one)
-
-        val subroutine = scope.definingSubroutine!!
-        var valueDt = source.inferType(program).getOrElse { throw FatalAstException("invalid dt") }
-        var valueSource: AsmAssignSource =
-            if(source is IFunctionCall) {
-                val resultReg = returnRegisterOfFunction(source.target)
-                assignExpressionToRegister(source, resultReg, valueDt in listOf(DataType.BYTE, DataType.WORD, DataType.FLOAT))
-                AsmAssignSource(SourceStorageKind.REGISTER, program, this, valueDt, register = resultReg)
-            } else {
-                AsmAssignSource.fromAstSource(source, program, this)
-            }
-
-        // the segments (except the last one): function calls taking one or more parameters and producing a value.
-        //   directly assign their first argument from the previous call's returnvalue (and take the rest, if any, from the call itself)
-        segments.dropLast(1).forEach {
-            it as IFunctionCall
-            valueDt = translateFunctionCallWithFirstArg(it, valueSource, false, subroutine)
-            val resultReg = returnRegisterOfFunction(it.target)
-            valueSource = AsmAssignSource(SourceStorageKind.REGISTER, program, this, valueDt, register = resultReg)
-        }
-        // the last segment: function call taking one or more parameters and optionally producing a result value.
-        val lastCall = segments.last() as IFunctionCall
-        if(isStatement) {
-            translateFunctionCallWithFirstArg(lastCall, valueSource, true, subroutine)
-        } else {
-            valueDt = translateFunctionCallWithFirstArg(lastCall, valueSource, false, subroutine)
-            if(pushResultOnEstack) {
-                when (valueDt) {
-                    in ByteDatatypes -> {
-                        out("  sta  P8ESTACK_LO,x |  dex")
-                    }
-                    in WordDatatypes -> {
-                        out("  sta  P8ESTACK_LO,x |  tya |  sta  P8ESTACK_HI,x |  dex")
-                    }
-                    DataType.FLOAT -> {
-                        out("  jsr  floats.push_fac1")
-                    }
-                    else -> throw AssemblyError("invalid dt")
-                }
-            }
-        }
-    }
-
-    private fun translateFunctionCallWithFirstArg(
-        fcall: IFunctionCall,
-        firstArg: AsmAssignSource,
-        isStatement: Boolean,
-        scope: Subroutine
-    ): DataType {
-
-        if(fcall.args.isNotEmpty())
-            TODO("deal with additional args (non-unary function): ${fcall.target.nameInSource} (... , ${fcall.args.joinToString(", ")})")
-
-        when(val targetStmt = fcall.target.targetStatement(program)!!) {
-            is BuiltinFunctionPlaceholder -> {
-                return if(isStatement) {
-                    translateBuiltinFunctionCallStatement(fcall, firstArg, scope)
-                    DataType.UNDEFINED
-                } else {
-                    translateBuiltinFunctionCallExpression(fcall, firstArg, scope)
-                }
-            }
-            is Subroutine -> {
-                val argDt = targetStmt.parameters.single().type
-                if(targetStmt.isAsmSubroutine) {
-                    // argument via registers
-                    val argRegister = targetStmt.asmParameterRegisters.single().registerOrPair!!
-                    val assignArgument = AsmAssignment(
-                        firstArg,
-                        AsmAssignTarget.fromRegisters(argRegister, argDt in SignedDatatypes, scope, program, this),
-                        false, program.memsizer, fcall.position
-                    )
-                    translateNormalAssignment(assignArgument)
-                } else {
-                    val assignArgument: AsmAssignment =
-                        if(functioncallAsmGen.optimizeIntArgsViaRegisters(targetStmt)) {
-                            // argument goes via registers as optimization
-                            val paramReg: RegisterOrPair = when(argDt) {
-                                in ByteDatatypes -> RegisterOrPair.A
-                                in WordDatatypes -> RegisterOrPair.AY
-                                DataType.FLOAT -> RegisterOrPair.FAC1
-                                else -> throw AssemblyError("invalid dt")
-                            }
-                            AsmAssignment(
-                                firstArg,
-                                AsmAssignTarget(TargetStorageKind.REGISTER, program, this, argDt, scope, register = paramReg),
-                                false, program.memsizer, fcall.position
-                            )
-                        } else {
-                            // arg goes via parameter variable
-                            val argVarName = asmVariableName(targetStmt.scopedName + targetStmt.parameters.single().name)
-                            AsmAssignment(
-                                firstArg,
-                                AsmAssignTarget(TargetStorageKind.VARIABLE, program, this, argDt, scope, argVarName),
-                                false, program.memsizer, fcall.position
-                            )
-                        }
-                    translateNormalAssignment(assignArgument)
-                }
-                if(targetStmt.shouldSaveX())
-                    saveRegisterLocal(CpuRegister.X, scope)
-                out("  jsr  ${asmSymbolName(fcall.target)}")
-                if(targetStmt.shouldSaveX())
-                    restoreRegisterLocal(CpuRegister.X)
-                return if(isStatement) DataType.UNDEFINED else targetStmt.returntypes.single()
-            }
-            else -> throw AssemblyError("invalid call target")
-        }
-    }
-
     internal fun popCpuStack(dt: DataType, target: VarDecl, scope: Subroutine?) {
         // note: because A is pushed first so popped last, saving A is often not required here.
         val parameter = target.subroutineParameter
@@ -3006,7 +2854,7 @@ $repeatLabel    lda  $counterVar
                 }
             }
         } else {
-            val tgt = AsmAssignTarget(TargetStorageKind.VARIABLE, program, this, target.datatype, scope, variableAsmName = asmVariableName(target.name))
+            val tgt = AsmAssignTarget(TargetStorageKind.VARIABLE, this, target.datatype, scope, variableAsmName = asmVariableName(target.scopedName))
             if (dt in ByteDatatypes) {
                 out("  pla")
                 assignRegister(RegisterOrPair.A, tgt)
@@ -3034,6 +2882,9 @@ $repeatLabel    lda  $counterVar
         }
     }
 
+    internal fun needAsaveForExpr(arg: Expression): Boolean =
+        arg !is NumericLiteral && arg !is IdentifierReference && (arg !is DirectMemoryRead || !arg.isSimple)
+
     private val subroutineExtrasCache = mutableMapOf<Subroutine, SubroutineExtraAsmInfo>()
 
     internal fun subroutineExtra(sub: Subroutine): SubroutineExtraAsmInfo {
@@ -3046,6 +2897,12 @@ $repeatLabel    lda  $counterVar
         else
             extra
     }
+
+    fun addMemorySlab(name: String, size: UInt, align: UInt, position: Position): String {
+        val prefixedName = "prog8_memoryslab_$name"
+        symbolTable.add(StMemorySlab(prefixedName, size, align, position))
+        return prefixedName
+    }
 }
 
 

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

@@ -59,7 +59,14 @@ internal fun optimizeAssembly(lines: MutableList<String>, machine: IMachineDefin
         numberOfOptimizations++
     }
 
-    // TODO more assembly optimizations
+    mods = optimizeSamePointerIndexing(linesByFourteen, machine, program)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFourteen = getLinesBy(lines, 14)
+        numberOfOptimizations++
+    }
+
+    // TODO more assembly peephole optimizations
 
     return numberOfOptimizations
 }
@@ -320,6 +327,48 @@ private fun optimizeSameAssignments(linesByFourteen: List<List<IndexedValue<Stri
     return mods
 }
 
+private fun optimizeSamePointerIndexing(linesByFourteen: List<List<IndexedValue<String>>>, machine: IMachineDefinition, program: Program): List<Modification> {
+
+    // Optimize same pointer indexing where for instance we load and store to the same ptr index in Y
+    // if Y isn't modified in between we can omit the second LDY:
+    //    ldy  #0
+    //    lda  (ptr),y
+    //    ora  #3       ; <-- instruction(s) that don't modify Y
+    //    ldy  #0       ; <-- can be removed
+    //    sta  (ptr),y
+
+    val mods = mutableListOf<Modification>()
+    for (lines in linesByFourteen) {
+        val first = lines[0].value.trimStart()
+        val second = lines[1].value.trimStart()
+        val third = lines[2].value.trimStart()
+        val fourth = lines[3].value.trimStart()
+        val fifth = lines[4].value.trimStart()
+        val sixth = lines[5].value.trimStart()
+
+        if(first.startsWith("ldy") && second.startsWith("lda") && fourth.startsWith("ldy") && fifth.startsWith("sta")) {
+            val firstvalue = first.substring(4)
+            val secondvalue = second.substring(4)
+            val fourthvalue = fourth.substring(4)
+            val fifthvalue = fifth.substring(4)
+            if("y" !in third && firstvalue==fourthvalue && secondvalue==fifthvalue && secondvalue.endsWith(",y") && fifthvalue.endsWith(",y")) {
+                mods.add(Modification(lines[3].index, true, null))
+            }
+        }
+        if(first.startsWith("ldy") && second.startsWith("lda") && fifth.startsWith("ldy") && sixth.startsWith("sta")) {
+            val firstvalue = first.substring(4)
+            val secondvalue = second.substring(4)
+            val fifthvalue = fifth.substring(4)
+            val sixthvalue = sixth.substring(4)
+            if("y" !in third && "y" !in fourth && firstvalue==fifthvalue && secondvalue==sixthvalue && secondvalue.endsWith(",y") && sixthvalue.endsWith(",y")) {
+                mods.add(Modification(lines[4].index, true, null))
+            }
+        }
+    }
+
+    return mods
+}
+
 private fun optimizeStoreLoadSame(linesByFour: List<List<IndexedValue<String>>>, machine: IMachineDefinition, program: Program): List<Modification> {
     // sta X + lda X,  sty X + ldy X,   stx X + ldx X  -> the second instruction can OFTEN be eliminated
     val mods = mutableListOf<Modification>()

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

@@ -3,6 +3,7 @@ package prog8.codegen.cpu6502
 import com.github.michaelbull.result.Ok
 import com.github.michaelbull.result.Result
 import com.github.michaelbull.result.mapError
+import prog8.ast.generatedLabelPrefix
 import prog8.code.core.*
 import java.io.File
 import java.nio.file.Path

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

@@ -6,13 +6,11 @@ import prog8.ast.Program
 import prog8.ast.expressions.*
 import prog8.ast.statements.ArrayIndex
 import prog8.ast.statements.BuiltinFunctionCallStatement
-import prog8.ast.statements.DirectMemoryWrite
 import prog8.ast.statements.Subroutine
 import prog8.code.core.*
 import prog8.codegen.cpu6502.assignment.*
 import prog8.compiler.BuiltinFunctions
 import prog8.compiler.FSignature
-import prog8.compiler.builtinFunctionReturnType
 
 
 internal class BuiltinFunctionsAsmGen(private val program: Program,
@@ -30,44 +28,6 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
         translateFunctioncall(fcall, func, discardResult = true, resultToStack = false, resultRegister = null)
     }
 
-    internal fun translateFunctionCallWithFirstArg(bfc: IFunctionCall, singleArg: AsmAssignSource, isStatement: Boolean, scope: Subroutine): DataType {
-        val name = bfc.target.nameInSource.single()
-        val func = BuiltinFunctions.getValue(name)
-        val argExpression =
-            when(singleArg.kind) {
-                SourceStorageKind.LITERALNUMBER -> singleArg.number!!
-                SourceStorageKind.EXPRESSION -> singleArg.expression!!
-                SourceStorageKind.ARRAY -> singleArg.array!!
-                else -> {
-                    // TODO make it so that we can assign efficiently from something else as an expression....namely: register(s)
-                    //      this is useful in pipe expressions for instance, to skip the use of a temporary variable
-                    //      but for now, just assign it to a temporary variable and use that as a source
-                    //      Idea: to do this without having to rewrite every single function in translateFunctioncall(),
-                    //            hack a special IdentifierReference like "!6502.A/X/Y/AX/AY/XY" to reference a cpu register
-                    val tempvar = asmgen.getTempVarName(singleArg.datatype)
-                    val assignTempvar = AsmAssignment(
-                        singleArg,
-                        AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, singleArg.datatype, scope, variableAsmName = asmgen.asmVariableName(tempvar)),
-                        false, program.memsizer, Position.DUMMY
-                    )
-                    assignAsmGen.translateNormalAssignment(assignTempvar)
-                    // now use an expression to assign this tempvar
-                    val ident = IdentifierReference(tempvar, Position.DUMMY)
-                    ident.linkParents(scope)
-                    ident
-                }
-            }
-        val argExpressions = mutableListOf(argExpression)
-        val fcall = BuiltinFunctionCall(IdentifierReference(listOf(name), Position.DUMMY), argExpressions, Position.DUMMY)
-        fcall.linkParents(scope)
-        translateFunctioncall(fcall, func, discardResult = false, resultToStack = false, null)
-        return if(isStatement) {
-            DataType.UNDEFINED
-        } else {
-            builtinFunctionReturnType(func.name).getOrElse { throw AssemblyError("unknown dt") }
-        }
-    }
-
     private fun translateFunctioncall(fcall: IFunctionCall, func: FSignature, discardResult: Boolean, resultToStack: Boolean, resultRegister: RegisterOrPair?) {
         if (discardResult && func.pure)
             return  // can just ignore the whole function call altogether
@@ -82,7 +42,6 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
             "lsb" -> funcLsb(fcall, resultToStack, resultRegister)
             "mkword" -> funcMkword(fcall, resultToStack, resultRegister)
             "abs" -> funcAbs(fcall, func, resultToStack, resultRegister, sscope)
-            "swap" -> funcSwap(fcall)
             "any", "all" -> funcAnyAll(fcall, func, resultToStack, resultRegister, sscope)
             "sgn" -> funcSgn(fcall, func, resultToStack, resultRegister, sscope)
             "rnd", "rndw" -> funcRnd(func, resultToStack, resultRegister, sscope)
@@ -180,20 +139,19 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
             throw AssemblyError("callfar only works on cx16 target at this time")
 
         val bank = fcall.args[0].constValue(program)?.number?.toInt()
-        val address = fcall.args[1].constValue(program)?.number?.toInt()
-        if(bank==null || address==null)
-            throw AssemblyError("callfar (jsrfar) requires constant arguments")
-
-        if(address !in 0xa000..0xbfff)
-            throw AssemblyError("callfar done on address outside of cx16 banked ram")
-        if(bank==0)
-            throw AssemblyError("callfar done on bank 0 which is reserved for the kernal")
-
+        val address = fcall.args[1].constValue(program)?.number?.toInt() ?: 0
         val argAddrArg = fcall.args[2]
+        if(bank==null)
+            throw AssemblyError("callfar (jsrfar) bank has to be a constant")
+        if(fcall.args[1].constValue(program) == null) {
+            assignAsmGen.assignExpressionToRegister(fcall.args[1], RegisterOrPair.AY, false)
+            asmgen.out("  sta  (+)+0 |  sty  (+)+1  ; store jsrfar address word")
+        }
+
         if(argAddrArg.constValue(program)?.number == 0.0) {
             asmgen.out("""
                 jsr  cx16.jsrfar
-                .word  ${address.toHex()}
++               .word  ${address.toHex()}
                 .byte  ${bank.toHex()}""")
         } else {
             when(argAddrArg) {
@@ -203,7 +161,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
                     asmgen.out("""
                         lda  ${asmgen.asmVariableName(argAddrArg.identifier)}
                         jsr  cx16.jsrfar
-                        .word  ${address.toHex()}
++                       .word  ${address.toHex()}
                         .byte  ${bank.toHex()}
                         sta  ${asmgen.asmVariableName(argAddrArg.identifier)}""")
                 }
@@ -211,7 +169,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
                     asmgen.out("""
                         lda  ${argAddrArg.number.toHex()}
                         jsr  cx16.jsrfar
-                        .word  ${address.toHex()}
++                       .word  ${address.toHex()}
                         .byte  ${bank.toHex()}
                         sta  ${argAddrArg.number.toHex()}""")
                 }
@@ -353,22 +311,17 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
         require(name.all { it.isLetterOrDigit() || it=='_' }) {"memory name should be a valid symbol name"}
         val size = (fcall.args[1] as NumericLiteral).number.toUInt()
         val align = (fcall.args[2] as NumericLiteral).number.toUInt()
-
-        val existing = allocations.getMemorySlab(name)
-        if(existing!=null && (existing.first!=size || existing.second!=align))
-            throw AssemblyError("memory slab '$name' already exists with a different size or alignment at ${fcall.position}")
-
-        val slabname = IdentifierReference(listOf("prog8_slabs", name), fcall.position)
+        val prefixedName = asmgen.addMemorySlab(name, size, align, fcall.position)
+        val slabname = IdentifierReference(listOf("prog8_slabs", prefixedName), fcall.position)
         slabname.linkParents(fcall)
         val src = AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, DataType.UWORD, expression = AddressOf(slabname, fcall.position))
         val target =
             if(resultToStack)
-                AsmAssignTarget(TargetStorageKind.STACK, program, asmgen, DataType.UWORD, null)
+                AsmAssignTarget(TargetStorageKind.STACK,  asmgen, DataType.UWORD, null)
             else
-                AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.AY, false, null, program, asmgen)
+                AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.AY, false, null, asmgen)
         val assign = AsmAssignment(src, target, false, program.memsizer, fcall.position)
         asmgen.translateNormalAssignment(assign)
-        allocations.allocateMemorySlab(name, size, align)
     }
 
     private fun funcSqrt16(fcall: IFunctionCall, func: FSignature, resultToStack: Boolean, resultRegister: RegisterOrPair?, scope: Subroutine?) {
@@ -377,7 +330,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
             asmgen.out("  jsr  prog8_lib.func_sqrt16_stack")
         else {
             asmgen.out("  jsr  prog8_lib.func_sqrt16_into_A")
-            assignAsmGen.assignRegisterByte(AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.A, false, scope, program, asmgen), CpuRegister.A)
+            assignAsmGen.assignRegisterByte(AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.A, false, scope, asmgen), CpuRegister.A)
         }
     }
 
@@ -512,6 +465,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
                         } else {
                             val ptrAndIndex = asmgen.pointerViaIndexRegisterPossible(what.addressExpression)
                             if(ptrAndIndex!=null) {
+                                asmgen.saveRegisterLocal(CpuRegister.X, (fcall as Node).definingSubroutine!!)
                                 asmgen.assignExpressionToRegister(ptrAndIndex.second, RegisterOrPair.X)
                                 asmgen.saveRegisterLocal(CpuRegister.X, (fcall as Node).definingSubroutine!!)
                                 asmgen.assignExpressionToRegister(ptrAndIndex.first, RegisterOrPair.AY)
@@ -520,6 +474,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
                                     sta  (+) + 1
                                     sty  (+) + 2
 +                                   ror  ${'$'}ffff,x           ; modified""")
+                                asmgen.restoreRegisterLocal(CpuRegister.X)
                             } else {
                                 asmgen.assignExpressionToRegister(what.addressExpression, RegisterOrPair.AY)
                                 asmgen.out("""
@@ -613,6 +568,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
                         } else {
                             val ptrAndIndex = asmgen.pointerViaIndexRegisterPossible(what.addressExpression)
                             if(ptrAndIndex!=null) {
+                                asmgen.saveRegisterLocal(CpuRegister.X, (fcall as Node).definingSubroutine!!)
                                 asmgen.assignExpressionToRegister(ptrAndIndex.second, RegisterOrPair.X)
                                 asmgen.saveRegisterLocal(CpuRegister.X, (fcall as Node).definingSubroutine!!)
                                 asmgen.assignExpressionToRegister(ptrAndIndex.first, RegisterOrPair.AY)
@@ -621,6 +577,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
                                     sta  (+) + 1
                                     sty  (+) + 2
 +                                   rol  ${'$'}ffff,x           ; modified""")
+                                asmgen.restoreRegisterLocal(CpuRegister.X)
                             } else {
                                 asmgen.assignExpressionToRegister(what.addressExpression, RegisterOrPair.AY)
                                 asmgen.out("""
@@ -655,7 +612,13 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
     }
 
     private fun translateRolRorArrayArgs(arrayvar: IdentifierReference, indexer: ArrayIndex, operation: String, dt: Char) {
-        asmgen.assignExpressionToVariable(AddressOf(arrayvar, arrayvar.position), "prog8_lib.${operation}_array_u${dt}._arg_target", DataType.UWORD, null)
+        if(arrayvar.targetVarDecl(program)!!.datatype==DataType.UWORD) {
+            if(dt!='b')
+                throw AssemblyError("non-array var indexing requires bytes dt")
+            asmgen.assignExpressionToVariable(arrayvar, "prog8_lib.${operation}_array_u${dt}._arg_target", DataType.UWORD, null)
+        } else {
+            asmgen.assignExpressionToVariable(AddressOf(arrayvar, arrayvar.position), "prog8_lib.${operation}_array_u${dt}._arg_target", DataType.UWORD, null)
+        }
         asmgen.assignExpressionToVariable(indexer.indexExpr, "prog8_lib.${operation}_array_u${dt}._arg_index", DataType.UBYTE, null)
     }
 
@@ -680,7 +643,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
                 DataType.FLOAT -> asmgen.out("  jsr  floats.func_sign_f_into_A")
                 else -> throw AssemblyError("weird type $dt")
             }
-            assignAsmGen.assignRegisterByte(AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.A, false, scope, program, asmgen), CpuRegister.A)
+            assignAsmGen.assignRegisterByte(AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.A, false, scope, asmgen), CpuRegister.A)
         }
     }
 
@@ -701,427 +664,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
                 DataType.ARRAY_F -> asmgen.out("  jsr  floats.func_${function.name}_f_into_A |  ldy  #0")
                 else -> throw AssemblyError("weird type $dt")
             }
-            assignAsmGen.assignRegisterByte(AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.A, false, scope, program, asmgen), CpuRegister.A)
-        }
-    }
-
-
-    private fun funcSwap(fcall: IFunctionCall) {
-        val first = fcall.args[0]
-        val second = fcall.args[1]
-
-        // optimized simple case: swap two variables
-        if(first is IdentifierReference && second is IdentifierReference) {
-            val firstName = asmgen.asmVariableName(first)
-            val secondName = asmgen.asmVariableName(second)
-            val dt = first.inferType(program)
-            if(dt istype DataType.BYTE || dt istype DataType.UBYTE) {
-                asmgen.out(" ldy  $firstName |  lda  $secondName |  sta  $firstName |  sty  $secondName")
-                return
-            }
-            if(dt istype DataType.WORD || dt istype DataType.UWORD) {
-                asmgen.out("""
-                    ldy  $firstName
-                    lda  $secondName
-                    sta  $firstName
-                    sty  $secondName
-                    ldy  $firstName+1
-                    lda  $secondName+1
-                    sta  $firstName+1
-                    sty  $secondName+1
-                """)
-                return
-            }
-            if(dt istype DataType.FLOAT) {
-                asmgen.out("""
-                    lda  #<$firstName
-                    sta  P8ZP_SCRATCH_W1
-                    lda  #>$firstName
-                    sta  P8ZP_SCRATCH_W1+1
-                    lda  #<$secondName
-                    sta  P8ZP_SCRATCH_W2
-                    lda  #>$secondName
-                    sta  P8ZP_SCRATCH_W2+1
-                    jsr  floats.func_swap_f
-                """)
-                return
-            }
-        }
-
-        // optimized simple case: swap two memory locations
-        if(first is DirectMemoryRead && second is DirectMemoryRead) {
-            val addr1 = (first.addressExpression as? NumericLiteral)?.number?.toHex()
-            val addr2 = (second.addressExpression as? NumericLiteral)?.number?.toHex()
-            val name1 = if(first.addressExpression is IdentifierReference) asmgen.asmVariableName(first.addressExpression as IdentifierReference) else null
-            val name2 = if(second.addressExpression is IdentifierReference) asmgen.asmVariableName(second.addressExpression as IdentifierReference) else null
-
-            when {
-                addr1!=null && addr2!=null -> {
-                    asmgen.out("  ldy  $addr1 |  lda  $addr2 |  sta  $addr1 |  sty  $addr2")
-                    return
-                }
-                addr1!=null && name2!=null -> {
-                    asmgen.out("  ldy  $addr1 |  lda  $name2 |  sta  $addr1 |  sty  $name2")
-                    return
-                }
-                name1!=null && addr2 != null -> {
-                    asmgen.out("  ldy  $name1 |  lda  $addr2 |  sta  $name1 |  sty  $addr2")
-                    return
-                }
-                name1!=null && name2!=null -> {
-                    asmgen.out("  ldy  $name1 |  lda  $name2 |  sta  $name1 |  sty  $name2")
-                    return
-                }
-                addr1==null && addr2==null && name1==null && name2==null -> {
-                    val firstExpr = first.addressExpression as? BinaryExpression
-                    val secondExpr = second.addressExpression as? BinaryExpression
-                    if(firstExpr!=null && secondExpr!=null) {
-                        val pointerVariable = firstExpr.left as? IdentifierReference
-                        val firstOffset = firstExpr.right
-                        val secondOffset = secondExpr.right
-                        if(pointerVariable != null
-                            && pointerVariable isSameAs secondExpr.left
-                            && firstExpr.operator == "+" && secondExpr.operator == "+"
-                            && (firstOffset is NumericLiteral || firstOffset is IdentifierReference || firstOffset is TypecastExpression)
-                            && (secondOffset is NumericLiteral || secondOffset is IdentifierReference || secondOffset is TypecastExpression)
-                        ) {
-                            if(firstOffset is NumericLiteral && secondOffset is NumericLiteral) {
-                                if(firstOffset!=secondOffset) {
-                                    swapArrayValues(
-                                        DataType.UBYTE,
-                                        asmgen.asmVariableName(pointerVariable), firstOffset,
-                                        asmgen.asmVariableName(pointerVariable), secondOffset
-                                    )
-                                    return
-                                }
-                            } else if(firstOffset is TypecastExpression && secondOffset is TypecastExpression) {
-                                if(firstOffset.type in WordDatatypes && secondOffset.type in WordDatatypes) {
-                                    val firstOffsetVar = firstOffset.expression as? IdentifierReference
-                                    val secondOffsetVar = secondOffset.expression as? IdentifierReference
-                                    if(firstOffsetVar!=null && secondOffsetVar!=null) {
-                                        if(firstOffsetVar!=secondOffsetVar) {
-                                            swapArrayValues(
-                                                DataType.UBYTE,
-                                                asmgen.asmVariableName(pointerVariable), firstOffsetVar,
-                                                asmgen.asmVariableName(pointerVariable), secondOffsetVar
-                                            )
-                                            return
-                                        }
-                                    }
-                                }
-                            } else if(firstOffset is IdentifierReference || secondOffset is IdentifierReference) {
-                                throw AssemblyError("expected a typecast-to-word for index variable at ${firstOffset.position} and/or ${secondOffset.position}")
-                            }
-                        }
-                    }
-                }
-            }
-        }
-
-        if(first is ArrayIndexedExpression && second is ArrayIndexedExpression) {
-            val arrayVarName1 = asmgen.asmVariableName(first.arrayvar)
-            val arrayVarName2 = asmgen.asmVariableName(second.arrayvar)
-            val elementIDt = first.inferType(program)
-            val elementDt = elementIDt.getOrElse { throw AssemblyError("unknown dt") }
-
-            val firstNum = first.indexer.indexExpr as? NumericLiteral
-            val firstVar = first.indexer.indexExpr as? IdentifierReference
-            val secondNum = second.indexer.indexExpr as? NumericLiteral
-            val secondVar = second.indexer.indexExpr as? IdentifierReference
-
-            if(firstNum!=null && secondNum!=null) {
-                swapArrayValues(elementDt, arrayVarName1, firstNum, arrayVarName2, secondNum)
-                return
-            } else if(firstVar!=null && secondVar!=null) {
-                swapArrayValues(elementDt, arrayVarName1, firstVar, arrayVarName2, secondVar)
-                return
-            } else if(firstNum!=null && secondVar!=null) {
-                swapArrayValues(elementDt, arrayVarName1, firstNum, arrayVarName2, secondVar)
-                return
-            } else if(firstVar!=null && secondNum!=null) {
-                swapArrayValues(elementDt, arrayVarName1, firstVar, arrayVarName2, secondNum)
-                return
-            }
-        }
-
-        // all other types of swap() calls are done via a temporary variable
-
-        fun targetFromExpr(expr: Expression, datatype: DataType): AsmAssignTarget {
-            return when (expr) {
-                is IdentifierReference -> AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, datatype, expr.definingSubroutine, variableAsmName = asmgen.asmVariableName(expr))
-                is ArrayIndexedExpression -> AsmAssignTarget(TargetStorageKind.ARRAY, program, asmgen, datatype, expr.definingSubroutine, array = expr)
-                is DirectMemoryRead -> AsmAssignTarget(TargetStorageKind.MEMORY, program, asmgen, datatype, expr.definingSubroutine, memory = DirectMemoryWrite(expr.addressExpression, expr.position))
-                else -> throw AssemblyError("invalid expression object $expr")
-            }
-        }
-
-        when(val datatype: DataType = first.inferType(program).getOr(DataType.UNDEFINED)) {
-            in ByteDatatypes, in WordDatatypes -> {
-                asmgen.assignExpressionToVariable(first, "P8ZP_SCRATCH_W1", datatype, null)
-                asmgen.assignExpressionToVariable(second, "P8ZP_SCRATCH_W2", datatype, null)
-                val assignFirst = AsmAssignment(
-                        AsmAssignSource(SourceStorageKind.VARIABLE, program, asmgen, datatype, variableAsmName = "P8ZP_SCRATCH_W2"),
-                        targetFromExpr(first, datatype),
-                        false, program.memsizer, first.position
-                )
-                val assignSecond = AsmAssignment(
-                        AsmAssignSource(SourceStorageKind.VARIABLE, program, asmgen, datatype, variableAsmName = "P8ZP_SCRATCH_W1"),
-                        targetFromExpr(second, datatype),
-                        false, program.memsizer, second.position
-                )
-                asmgen.translateNormalAssignment(assignFirst)
-                asmgen.translateNormalAssignment(assignSecond)
-            }
-            DataType.FLOAT -> {
-                // via temp variable and FAC1
-                asmgen.assignExpressionTo(first, AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, DataType.FLOAT, first.definingSubroutine, "floats.tempvar_swap_float"))
-                asmgen.assignExpressionTo(second, AsmAssignTarget(TargetStorageKind.REGISTER, program, asmgen, DataType.FLOAT, null, register=RegisterOrPair.FAC1))
-                asmgen.translateNormalAssignment(
-                    AsmAssignment(
-                        AsmAssignSource(SourceStorageKind.REGISTER, program, asmgen, datatype, register = RegisterOrPair.FAC1),
-                        targetFromExpr(first, datatype),
-                        false, program.memsizer, first.position
-                    )
-                )
-                asmgen.translateNormalAssignment(
-                    AsmAssignment(
-                        AsmAssignSource(SourceStorageKind.VARIABLE, program, asmgen, datatype, "floats.tempvar_swap_float"),
-                        targetFromExpr(second, datatype),
-                        false, program.memsizer, second.position
-                    )
-                )
-            }
-            else -> throw AssemblyError("weird swap dt")
-        }
-    }
-
-    private fun swapArrayValues(elementDt: DataType, arrayVarName1: String, indexValue1: NumericLiteral, arrayVarName2: String, indexValue2: NumericLiteral) {
-        val index1 = indexValue1.number.toInt() * program.memsizer.memorySize(elementDt)
-        val index2 = indexValue2.number.toInt() * program.memsizer.memorySize(elementDt)
-        when(elementDt) {
-            DataType.UBYTE, DataType.BYTE -> {
-                asmgen.out("""
-                    lda  $arrayVarName1+$index1
-                    ldy  $arrayVarName2+$index2
-                    sta  $arrayVarName2+$index2
-                    sty  $arrayVarName1+$index1
-                """)
-            }
-            DataType.UWORD, DataType.WORD -> {
-                asmgen.out("""
-                    lda  $arrayVarName1+$index1
-                    ldy  $arrayVarName2+$index2
-                    sta  $arrayVarName2+$index2
-                    sty  $arrayVarName1+$index1
-                    lda  $arrayVarName1+$index1+1
-                    ldy  $arrayVarName2+$index2+1
-                    sta  $arrayVarName2+$index2+1
-                    sty  $arrayVarName1+$index1+1
-                """)
-            }
-            DataType.FLOAT -> {
-                asmgen.out("""
-                    lda  #<(${arrayVarName1}+$index1)
-                    sta  P8ZP_SCRATCH_W1
-                    lda  #>(${arrayVarName1}+$index1)
-                    sta  P8ZP_SCRATCH_W1+1
-                    lda  #<(${arrayVarName2}+$index2)
-                    sta  P8ZP_SCRATCH_W2
-                    lda  #>(${arrayVarName2}+$index2)
-                    sta  P8ZP_SCRATCH_W2+1
-                    jsr  floats.func_swap_f
-                """)
-            }
-            else -> throw AssemblyError("invalid aray elt type")
-        }
-    }
-
-    private fun swapArrayValues(elementDt: DataType, arrayVarName1: String, indexName1: IdentifierReference, arrayVarName2: String, indexName2: IdentifierReference) {
-        val idxAsmName1 = asmgen.asmVariableName(indexName1)
-        val idxAsmName2 = asmgen.asmVariableName(indexName2)
-        when(elementDt) {
-            DataType.UBYTE, DataType.BYTE -> {
-                asmgen.out("""
-                    stx  P8ZP_SCRATCH_REG
-                    ldx  $idxAsmName1
-                    ldy  $idxAsmName2
-                    lda  $arrayVarName1,x
-                    pha
-                    lda  $arrayVarName2,y
-                    sta  $arrayVarName1,x
-                    pla
-                    sta  $arrayVarName2,y
-                    ldx  P8ZP_SCRATCH_REG
-                """)
-            }
-            DataType.UWORD, DataType.WORD -> {
-                asmgen.out("""
-                    stx  P8ZP_SCRATCH_REG
-                    lda  $idxAsmName1
-                    asl  a
-                    tax
-                    lda  $idxAsmName2
-                    asl  a
-                    tay
-                    lda  $arrayVarName1,x
-                    pha
-                    lda  $arrayVarName2,y
-                    sta  $arrayVarName1,x
-                    pla
-                    sta  $arrayVarName2,y
-                    lda  $arrayVarName1+1,x
-                    pha
-                    lda  $arrayVarName2+1,y
-                    sta  $arrayVarName1+1,x
-                    pla
-                    sta  $arrayVarName2+1,y
-                    ldx  P8ZP_SCRATCH_REG
-                """)
-            }
-            DataType.FLOAT -> {
-                asmgen.out("""
-                    lda  #>$arrayVarName1
-                    sta  P8ZP_SCRATCH_W1+1
-                    lda  $idxAsmName1
-                    asl  a
-                    asl  a
-                    clc
-                    adc  $idxAsmName1
-                    adc  #<$arrayVarName1
-                    sta  P8ZP_SCRATCH_W1
-                    bcc  +
-                    inc  P8ZP_SCRATCH_W1+1
-+                   lda  #>$arrayVarName2
-                    sta  P8ZP_SCRATCH_W2+1
-                    lda  $idxAsmName2
-                    asl  a
-                    asl  a
-                    clc
-                    adc  $idxAsmName2
-                    adc  #<$arrayVarName2
-                    sta  P8ZP_SCRATCH_W2
-                    bcc  +
-                    inc  P8ZP_SCRATCH_W2+1
-+                   jsr  floats.func_swap_f                                   
-                """)
-            }
-            else -> throw AssemblyError("invalid aray elt type")
-        }
-    }
-
-    private fun swapArrayValues(elementDt: DataType, arrayVarName1: String, indexValue1: NumericLiteral, arrayVarName2: String, indexName2: IdentifierReference) {
-        val index1 = indexValue1.number.toInt() * program.memsizer.memorySize(elementDt)
-        val idxAsmName2 = asmgen.asmVariableName(indexName2)
-        when(elementDt) {
-            DataType.UBYTE, DataType.BYTE -> {
-                asmgen.out("""
-                    lda  $arrayVarName1 + $index1
-                    pha
-                    ldy  $idxAsmName2
-                    lda  $arrayVarName2,y
-                    sta  $arrayVarName1 + $index1
-                    pla
-                    sta  $arrayVarName2,y
-                """)
-            }
-            DataType.UWORD, DataType.WORD -> {
-                asmgen.out("""
-                    lda  $arrayVarName1 + $index1
-                    pha
-                    lda  $idxAsmName2
-                    asl  a
-                    tay
-                    lda  $arrayVarName2,y
-                    sta  $arrayVarName1 + $index1
-                    pla
-                    sta  $arrayVarName2,y
-                    lda  $arrayVarName1 + $index1+1
-                    pha
-                    lda  $arrayVarName2+1,y
-                    sta  $arrayVarName1 + $index1+1
-                    pla
-                    sta  $arrayVarName2+1,y
-                """)
-            }
-            DataType.FLOAT -> {
-                asmgen.out("""
-                    lda  #<(${arrayVarName1}+$index1)
-                    sta  P8ZP_SCRATCH_W1
-                    lda  #>(${arrayVarName1}+$index1)
-                    sta  P8ZP_SCRATCH_W1+1
-                    lda  #>$arrayVarName1
-                    sta  P8ZP_SCRATCH_W1+1
-                    lda  $idxAsmName2
-                    asl  a
-                    asl  a
-                    clc
-                    adc  $idxAsmName2
-                    adc  #<$arrayVarName1
-                    sta  P8ZP_SCRATCH_W1
-                    bcc  +
-                    inc  P8ZP_SCRATCH_W1+1
-+                   jsr  floats.func_swap_f
-                """)
-            }
-            else -> throw AssemblyError("invalid aray elt type")
-        }
-    }
-
-    private fun swapArrayValues(elementDt: DataType, arrayVarName1: String, indexName1: IdentifierReference, arrayVarName2: String, indexValue2: NumericLiteral) {
-        val idxAsmName1 = asmgen.asmVariableName(indexName1)
-        val index2 = indexValue2.number.toInt() * program.memsizer.memorySize(elementDt)
-        when(elementDt) {
-            DataType.UBYTE, DataType.BYTE -> {
-                asmgen.out("""
-                    lda  $arrayVarName2 + $index2
-                    pha
-                    ldy  $idxAsmName1
-                    lda  $arrayVarName1,y
-                    sta  $arrayVarName2 + $index2
-                    pla
-                    sta  $arrayVarName1,y
-                """)
-            }
-            DataType.UWORD, DataType.WORD -> {
-                asmgen.out("""
-                    lda  $arrayVarName2 + $index2
-                    pha
-                    lda  $idxAsmName1
-                    asl  a
-                    tay
-                    lda  $arrayVarName1,y
-                    sta  $arrayVarName2 + $index2
-                    pla
-                    sta  $arrayVarName1,y
-                    lda  $arrayVarName2 + $index2+1
-                    pha
-                    lda  $arrayVarName1+1,y
-                    sta  $arrayVarName2 + $index2+1
-                    pla
-                    sta  $arrayVarName1+1,y
-                """)
-            }
-            DataType.FLOAT -> {
-                asmgen.out("""
-                    lda  #>$arrayVarName1
-                    sta  P8ZP_SCRATCH_W1+1
-                    lda  $idxAsmName1
-                    asl  a
-                    asl  a
-                    clc
-                    adc  $idxAsmName1
-                    adc  #<$arrayVarName1
-                    sta  P8ZP_SCRATCH_W1
-                    bcc  +
-                    inc  P8ZP_SCRATCH_W1+1
-+                   lda  #<(${arrayVarName2}+$index2)
-                    sta  P8ZP_SCRATCH_W2
-                    lda  #>(${arrayVarName2}+$index2)
-                    sta  P8ZP_SCRATCH_W2+1
-                    jsr  floats.func_swap_f
-                """)
-            }
-            else -> throw AssemblyError("invalid aray elt type")
+            assignAsmGen.assignRegisterByte(AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.A, false, scope, asmgen), CpuRegister.A)
         }
     }
 
@@ -1144,7 +687,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
                 DataType.WORD -> asmgen.out("  jsr  prog8_lib.abs_w_into_AY")
                 else -> throw AssemblyError("weird type")
             }
-            assignAsmGen.assignRegisterpairWord(AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.AY, false, scope, program, asmgen), RegisterOrPair.AY)
+            assignAsmGen.assignRegisterpairWord(AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.AY, false, scope, asmgen), RegisterOrPair.AY)
         }
     }
 
@@ -1155,7 +698,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
                     asmgen.out("  jsr  prog8_lib.func_rnd_stack")
                 else {
                     asmgen.out("  jsr  math.randbyte")
-                    assignAsmGen.assignRegisterByte(AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.A, false, scope, program, asmgen), CpuRegister.A)
+                    assignAsmGen.assignRegisterByte(AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.A, false, scope, asmgen), CpuRegister.A)
                 }
             }
             "rndw" -> {
@@ -1163,7 +706,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
                     asmgen.out("  jsr  prog8_lib.func_rndw_stack")
                 else {
                     asmgen.out("  jsr  math.randword")
-                    assignAsmGen.assignRegisterpairWord(AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.AY, false, scope, program, asmgen), RegisterOrPair.AY)
+                    assignAsmGen.assignRegisterpairWord(AsmAssignTarget.fromRegisters(resultRegister ?: RegisterOrPair.AY, false, scope, asmgen), RegisterOrPair.AY)
                 }
             }
             else -> throw AssemblyError("wrong func")
@@ -1312,14 +855,14 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
             asmgen.out("  sta  P8ESTACK_LO,x |  tya |  sta  P8ESTACK_HI,x |  dex")
         } else {
             val reg = resultRegister ?: RegisterOrPair.AY
-            var needAsave = !(fcall.args[0] is DirectMemoryRead || fcall.args[0] is NumericLiteral || fcall.args[0] is IdentifierReference)
+            var needAsave = asmgen.needAsaveForExpr(fcall.args[0])
             if(!needAsave) {
                 val mr0 = fcall.args[0] as? DirectMemoryRead
                 val mr1 = fcall.args[1] as? DirectMemoryRead
                 if (mr0 != null)
-                    needAsave = mr0.addressExpression !is NumericLiteral && mr0.addressExpression !is IdentifierReference
+                    needAsave =  mr0.addressExpression !is NumericLiteral
                 if (mr1 != null)
-                    needAsave = needAsave or (mr1.addressExpression !is NumericLiteral && mr1.addressExpression !is IdentifierReference)
+                    needAsave = needAsave or (mr1.addressExpression !is NumericLiteral)
             }
             when(reg) {
                 RegisterOrPair.AX -> {
@@ -1536,7 +1079,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
                             AsmAssignSource.fromAstSource(value, program, asmgen)
                         }
                     }
-                    val tgt = AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, conv.dt, null, variableAsmName = varname)
+                    val tgt = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, conv.dt, null, variableAsmName = varname)
                     val assign = AsmAssignment(src, tgt, false, program.memsizer, value.position)
                     asmgen.translateNormalAssignment(assign)
                 }
@@ -1552,7 +1095,7 @@ internal class BuiltinFunctionsAsmGen(private val program: Program,
                             AsmAssignSource.fromAstSource(value, program, asmgen)
                         }
                     }
-                    val tgt = AsmAssignTarget.fromRegisters(conv.reg!!, false, null, program, asmgen)
+                    val tgt = AsmAssignTarget.fromRegisters(conv.reg!!, false, null, asmgen)
                     val assign = AsmAssignment(src, tgt, false, program.memsizer, value.position)
                     asmgen.translateNormalAssignment(assign)
                 }

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

@@ -34,8 +34,6 @@ internal class ExpressionsAsmGen(private val program: Program,
             is IdentifierReference -> translateExpression(expression)
             is FunctionCallExpression -> translateFunctionCallResultOntoStack(expression)
             is BuiltinFunctionCall -> asmgen.translateBuiltinFunctionCallExpression(expression, true, null)
-            is PipeExpression -> asmgen.translatePipeExpression(expression.source, expression.segments,
-                                                                expression, isStatement = false, pushResultOnEstack = true )
             is ContainmentCheck -> throw AssemblyError("containment check as complex expression value is not supported")
             is ArrayLiteral, is StringLiteral -> throw AssemblyError("no asm gen for string/array literal value assignment - should have been replaced by a variable")
             is RangeExpression -> throw AssemblyError("range expression should have been changed into array values")
@@ -138,7 +136,7 @@ internal class ExpressionsAsmGen(private val program: Program,
     private fun translateExpression(typecast: TypecastExpression) {
         translateExpressionInternal(typecast.expression)
         when(typecast.expression.inferType(program).getOr(DataType.UNDEFINED)) {
-            DataType.UBYTE -> {
+            DataType.UBYTE, DataType.BOOL -> {
                 when(typecast.type) {
                     DataType.UBYTE, DataType.BYTE -> {}
                     DataType.UWORD, DataType.WORD -> {
@@ -521,12 +519,37 @@ internal class ExpressionsAsmGen(private val program: Program,
                     val rightVal = expr.right.constValue(program)?.number?.toInt()
                     if(rightVal!=null && rightVal==2) {
                         translateExpressionInternal(expr.left)
-                        when(leftDt) {
-                            DataType.UBYTE -> asmgen.out("  lsr  P8ESTACK_LO+1,x")
-                            DataType.BYTE -> asmgen.out("  lda  P8ESTACK_LO+1,x |  asl  a |  ror  P8ESTACK_LO+1,x")
-                            DataType.UWORD -> asmgen.out("  lsr  P8ESTACK_HI+1,x |  ror  P8ESTACK_LO+1,x")
-                            DataType.WORD -> asmgen.out("  lda  P8ESTACK_HI+1,x |  asl  a |  ror  P8ESTACK_HI+1,x |  ror  P8ESTACK_LO+1,x")
-                            else -> throw AssemblyError("wrong dt")
+                        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
                     }
@@ -534,8 +557,8 @@ internal class ExpressionsAsmGen(private val program: Program,
             }
             in ComparisonOperators -> {
                 if(leftDt in NumericDatatypes && rightDt in NumericDatatypes) {
-                    val rightVal = expr.right.constValue(program)?.number?.toInt()
-                    if(rightVal==0)
+                    val rightVal = expr.right.constValue(program)?.number
+                    if(rightVal==0.0)
                         return translateComparisonWithZero(expr.left, leftDt, expr.operator)
                 }
             }
@@ -562,6 +585,42 @@ internal class ExpressionsAsmGen(private val program: Program,
     }
 
     private fun translateComparisonWithZero(expr: Expression, 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) {
             "==" -> {
@@ -666,22 +725,6 @@ internal class ExpressionsAsmGen(private val program: Program,
                     else -> throw AssemblyError("weird type")
                 }
             }
-            "not" -> {
-                when(type) {
-                    // if reg==0 ->
-                    /*
-        lda  P8ESTACK_LO+1,x
-		beq  +
-		lda  #1
-+		eor  #1
-		sta  P8ESTACK_LO+1,x
-		rts
-                     */
-                    in ByteDatatypes -> asmgen.out("  jsr  prog8_lib.not_byte")
-                    in WordDatatypes -> asmgen.out("  jsr  prog8_lib.not_word")
-                    else -> throw AssemblyError("weird type")
-                }
-            }
             else -> throw AssemblyError("invalid prefix operator ${expr.operator}")
         }
     }
@@ -692,6 +735,25 @@ internal class ExpressionsAsmGen(private val program: Program,
             throw AssemblyError("unknown dt")
         val elementDt = elementIDt.getOr(DataType.UNDEFINED)
         val arrayVarName = asmgen.asmVariableName(arrayExpr.arrayvar)
+
+        val arrayVarDecl = arrayExpr.arrayvar.targetVarDecl(program)!!
+        if(arrayVarDecl.datatype==DataType.UWORD) {
+            // indexing a pointer var instead of a real array or string
+            if(elementDt !in ByteDatatypes)
+                throw AssemblyError("non-array var indexing requires bytes dt")
+            if(arrayExpr.inferType(program) isnot DataType.UBYTE)
+                throw AssemblyError("non-array var indexing requires bytes index")
+            asmgen.loadScaledArrayIndexIntoRegister(arrayExpr, elementDt, CpuRegister.Y)
+            if(asmgen.isZpVar(arrayExpr.arrayvar)) {
+                asmgen.out("  lda  ($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.indexer.constIndex()
         if(constIndexNum!=null) {
             val indexValue = constIndexNum * program.memsizer.memorySize(elementDt)
@@ -767,9 +829,6 @@ internal class ExpressionsAsmGen(private val program: Program,
             "&" -> asmgen.out("  jsr  prog8_lib.bitand_b")
             "^" -> asmgen.out("  jsr  prog8_lib.bitxor_b")
             "|" -> asmgen.out("  jsr  prog8_lib.bitor_b")
-            "and" -> asmgen.out("  jsr  prog8_lib.and_b")
-            "or" -> asmgen.out("  jsr  prog8_lib.or_b")
-            "xor" -> asmgen.out("  jsr  prog8_lib.xor_b")
             else -> throw AssemblyError("invalid operator $operator")
         }
     }
@@ -801,9 +860,6 @@ internal class ExpressionsAsmGen(private val program: Program,
             "&" -> asmgen.out("  jsr  prog8_lib.bitand_w")
             "^" -> asmgen.out("  jsr  prog8_lib.bitxor_w")
             "|" -> asmgen.out("  jsr  prog8_lib.bitor_w")
-            "and" -> asmgen.out("  jsr  prog8_lib.and_w")
-            "or" -> asmgen.out("  jsr  prog8_lib.or_w")
-            "xor" -> asmgen.out("  jsr  prog8_lib.xor_w")
             else -> throw AssemblyError("invalid operator $operator")
         }
     }
@@ -820,7 +876,7 @@ internal class ExpressionsAsmGen(private val program: Program,
             ">=" -> asmgen.out("  jsr  floats.greatereq_f")
             "==" -> asmgen.out("  jsr  floats.equal_f")
             "!=" -> asmgen.out("  jsr  floats.notequal_f")
-            "%", "<<", ">>", "&", "^", "|", "and", "or", "xor" -> throw AssemblyError("requires integer datatype")
+            "%", "<<", ">>", "&", "^", "|" -> throw AssemblyError("requires integer datatype")
             else -> throw AssemblyError("invalid operator $operator")
         }
     }

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

@@ -31,10 +31,10 @@ internal class ForLoopsAsmGen(private val program: Program, private val asmgen:
     }
 
     private fun translateForOverNonconstRange(stmt: ForLoop, iterableDt: DataType, range: RangeExpression) {
-        val loopLabel = asmgen.makeLabel("for_loop")
-        val endLabel = asmgen.makeLabel("for_end")
-        val modifiedLabel = asmgen.makeLabel("for_modified")
-        val modifiedLabel2 = asmgen.makeLabel("for_modifiedb")
+        val loopLabel = program.makeLabel("for_loop")
+        val endLabel = program.makeLabel("for_end")
+        val modifiedLabel = program.makeLabel("for_modified")
+        val modifiedLabel2 = program.makeLabel("for_modifiedb")
         asmgen.loopEndLabels.push(endLabel)
         val stepsize=range.step.constValue(program)!!.number.toInt()
 
@@ -238,8 +238,8 @@ $endLabel""")
     }
 
     private fun translateForOverIterableVar(stmt: ForLoop, iterableDt: DataType, ident: IdentifierReference) {
-        val loopLabel = asmgen.makeLabel("for_loop")
-        val endLabel = asmgen.makeLabel("for_end")
+        val loopLabel = program.makeLabel("for_loop")
+        val endLabel = program.makeLabel("for_end")
         asmgen.loopEndLabels.push(endLabel)
         val iterableName = asmgen.asmVariableName(ident)
         val decl = ident.targetVarDecl(program)!!
@@ -263,7 +263,7 @@ $endLabel""")
             }
             DataType.ARRAY_UB, DataType.ARRAY_B -> {
                 val length = decl.arraysize!!.constIndex()!!
-                val indexVar = asmgen.makeLabel("for_index")
+                val indexVar = program.makeLabel("for_index")
                 asmgen.out("""
                     ldy  #0
 $loopLabel          sty  $indexVar
@@ -299,7 +299,7 @@ $loopLabel          sty  $indexVar
             }
             DataType.ARRAY_W, DataType.ARRAY_UW -> {
                 val length = decl.arraysize!!.constIndex()!! * 2
-                val indexVar = asmgen.makeLabel("for_index")
+                val indexVar = program.makeLabel("for_index")
                 val loopvarName = asmgen.asmVariableName(stmt.loopVar)
                 asmgen.out("""
                     ldy  #0
@@ -359,8 +359,8 @@ $loopLabel          sty  $indexVar
         }
 
         // not one of the easy cases, generate more complex code...
-        val loopLabel = asmgen.makeLabel("for_loop")
-        val endLabel = asmgen.makeLabel("for_end")
+        val loopLabel = program.makeLabel("for_loop")
+        val endLabel = program.makeLabel("for_end")
         asmgen.loopEndLabels.push(endLabel)
         when(iterableDt) {
             DataType.ARRAY_B, DataType.ARRAY_UB -> {
@@ -471,8 +471,8 @@ $loopLabel""")
     }
 
     private fun translateForSimpleByteRangeAsc(stmt: ForLoop, range: IntProgression) {
-        val loopLabel = asmgen.makeLabel("for_loop")
-        val endLabel = asmgen.makeLabel("for_end")
+        val loopLabel = program.makeLabel("for_loop")
+        val endLabel = program.makeLabel("for_end")
         asmgen.loopEndLabels.push(endLabel)
         val varname = asmgen.asmVariableName(stmt.loopVar)
         asmgen.out("""
@@ -497,8 +497,8 @@ $endLabel""")
     }
 
     private fun translateForSimpleByteRangeDesc(stmt: ForLoop, range: IntProgression) {
-        val loopLabel = asmgen.makeLabel("for_loop")
-        val endLabel = asmgen.makeLabel("for_end")
+        val loopLabel = program.makeLabel("for_loop")
+        val endLabel = program.makeLabel("for_end")
         asmgen.loopEndLabels.push(endLabel)
         val varname = asmgen.asmVariableName(stmt.loopVar)
         asmgen.out("""
@@ -534,8 +534,8 @@ $endLabel""")
     }
 
     private fun translateForSimpleWordRangeAsc(stmt: ForLoop, range: IntProgression) {
-        val loopLabel = asmgen.makeLabel("for_loop")
-        val endLabel = asmgen.makeLabel("for_end")
+        val loopLabel = program.makeLabel("for_loop")
+        val endLabel = program.makeLabel("for_end")
         asmgen.loopEndLabels.push(endLabel)
         val varname = asmgen.asmVariableName(stmt.loopVar)
         asmgen.out("""
@@ -561,8 +561,8 @@ $loopLabel""")
     }
 
     private fun translateForSimpleWordRangeDesc(stmt: ForLoop, range: IntProgression) {
-        val loopLabel = asmgen.makeLabel("for_loop")
-        val endLabel = asmgen.makeLabel("for_end")
+        val loopLabel = program.makeLabel("for_loop")
+        val endLabel = program.makeLabel("for_end")
         asmgen.loopEndLabels.push(endLabel)
         val varname = asmgen.asmVariableName(stmt.loopVar)
         asmgen.out("""

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

@@ -7,7 +7,10 @@ import prog8.ast.expressions.AddressOf
 import prog8.ast.expressions.Expression
 import prog8.ast.expressions.IdentifierReference
 import prog8.ast.expressions.NumericLiteral
-import prog8.ast.statements.*
+import prog8.ast.statements.FunctionCallStatement
+import prog8.ast.statements.InlineAssembly
+import prog8.ast.statements.Subroutine
+import prog8.ast.statements.SubroutineParameter
 import prog8.code.core.*
 import prog8.codegen.cpu6502.assignment.AsmAssignSource
 import prog8.codegen.cpu6502.assignment.AsmAssignTarget
@@ -35,17 +38,6 @@ internal class FunctionCallAsmGen(private val program: Program, private val asmg
         }
     }
 
-    internal fun saveXbeforeCall(gosub: GoSub) {
-        val sub = gosub.identifier.targetSubroutine(program)
-        if(sub?.shouldSaveX()==true) {
-            val regSaveOnStack = sub.asmAddress==null       // rom-routines don't require registers to be saved on stack, normal subroutines do because they can contain nested calls
-            if(regSaveOnStack)
-                asmgen.saveRegisterStack(CpuRegister.X, sub.shouldKeepA().saveOnEntry)
-            else
-                asmgen.saveRegisterLocal(CpuRegister.X, gosub.definingSubroutine!!)
-        }
-    }
-
     internal fun restoreXafterCall(stmt: IFunctionCall) {
         val sub = stmt.target.targetSubroutine(program) ?: throw AssemblyError("undefined subroutine ${stmt.target}")
         if(sub.shouldSaveX()) {
@@ -57,17 +49,6 @@ internal class FunctionCallAsmGen(private val program: Program, private val asmg
         }
     }
 
-    internal fun restoreXafterCall(gosub: GoSub) {
-        val sub = gosub.identifier.targetSubroutine(program)
-        if(sub?.shouldSaveX()==true) {
-            val regSaveOnStack = sub.asmAddress==null       // rom-routines don't require registers to be saved on stack, normal subroutines do because they can contain nested calls
-            if(regSaveOnStack)
-                asmgen.restoreRegisterStack(CpuRegister.X, sub.shouldKeepA().saveOnReturn)
-            else
-                asmgen.restoreRegisterLocal(CpuRegister.X)
-        }
-    }
-
     internal fun optimizeIntArgsViaRegisters(sub: Subroutine) =
         (sub.parameters.size==1 && sub.parameters[0].type in IntegerDatatypes)
                 || (sub.parameters.size==2 && sub.parameters[0].type in ByteDatatypes && sub.parameters[1].type in ByteDatatypes)
@@ -81,11 +62,6 @@ internal class FunctionCallAsmGen(private val program: Program, private val asmg
         val sub = call.target.targetSubroutine(program) ?: throw AssemblyError("undefined subroutine ${call.target}")
         val subAsmName = asmgen.asmSymbolName(call.target)
 
-        if(!isExpression && !sub.isAsmSubroutine) {
-            if(!optimizeIntArgsViaRegisters(sub))
-                throw AssemblyError("functioncall statements to non-asmsub should have been replaced by GoSub $call")
-        }
-
         if(sub.isAsmSubroutine) {
             argumentsViaRegisters(sub, call)
             if (sub.inline && asmgen.options.optimize) {
@@ -111,10 +87,10 @@ internal class FunctionCallAsmGen(private val program: Program, private val asmg
                 } else {
                     // 2 byte params, second in Y, first in A
                     argumentViaRegister(sub, IndexedValue(0, sub.parameters[0]), call.args[0], RegisterOrPair.A)
-                    if(!call.args[1].isSimple)
+                    if(asmgen.needAsaveForExpr(call.args[1]))
                         asmgen.out("  pha")
                     argumentViaRegister(sub, IndexedValue(1, sub.parameters[1]), call.args[1], RegisterOrPair.Y)
-                    if(!call.args[1].isSimple)
+                    if(asmgen.needAsaveForExpr(call.args[1]))
                         asmgen.out("  pla")
                 }
             } else {
@@ -159,7 +135,7 @@ internal class FunctionCallAsmGen(private val program: Program, private val asmg
         }
         argOrder.forEach {
             val param = callee.parameters[it]
-            val targetVar = callee.searchAsmParameter(param.name)!!
+            val targetVar = callee.searchParameter(param.name)!!
             asmgen.popCpuStack(param.type, targetVar, (call as Node).definingSubroutine)
         }
     }
@@ -234,10 +210,10 @@ internal class FunctionCallAsmGen(private val program: Program, private val asmg
             } else {
                 val target: AsmAssignTarget =
                     if(parameter.value.type in ByteDatatypes && (register==RegisterOrPair.AX || register == RegisterOrPair.AY || register==RegisterOrPair.XY || register in Cx16VirtualRegisters))
-                        AsmAssignTarget(TargetStorageKind.REGISTER, program, asmgen, parameter.value.type, sub, register = register)
+                        AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, parameter.value.type, sub, register = register)
                     else {
                         val signed = parameter.value.type == DataType.BYTE || parameter.value.type == DataType.WORD
-                        AsmAssignTarget.fromRegisters(register, signed, sub, program, asmgen)
+                        AsmAssignTarget.fromRegisters(register, signed, sub, asmgen)
                     }
                 val src = if(valueDt in PassByReferenceDatatypes) {
                     if(value is IdentifierReference) {

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

@@ -44,6 +44,15 @@ internal class ProgramAndVarsGen(
 
         if(errors.noErrors())  {
             program.allBlocks.forEach { block2asm(it) }
+
+            // the global list of all floating point constants for the whole program
+            asmgen.out("; global float constants")
+            for (flt in allocator.globalFloatConsts) {
+                val floatFill = compTarget.machine.getFloatAsmBytes(flt.key)
+                val floatvalue = flt.key
+                asmgen.out("${flt.value}\t.byte  $floatFill  ; float $floatvalue")
+            }
+
             memorySlabs()
             footer()
         }
@@ -70,8 +79,17 @@ internal class ProgramAndVarsGen(
         asmgen.out("P8ZP_SCRATCH_REG = ${zp.SCRATCH_REG}")
         asmgen.out("P8ZP_SCRATCH_W1 = ${zp.SCRATCH_W1}    ; word")
         asmgen.out("P8ZP_SCRATCH_W2 = ${zp.SCRATCH_W2}    ; word")
+        asmgen.out(".weak")   // hack to allow user to override the following two with command line redefinition (however, just use '-esa' command line option instead!)
         asmgen.out("P8ESTACK_LO = ${compTarget.machine.ESTACK_LO.toHex()}")
         asmgen.out("P8ESTACK_HI = ${compTarget.machine.ESTACK_HI.toHex()}")
+        asmgen.out(".endweak")
+
+        if(options.symbolDefs.isNotEmpty()) {
+            asmgen.out("; -- user supplied symbols on the command line")
+            for((name, value) in options.symbolDefs) {
+                asmgen.out("$name = $value")
+            }
+        }
 
         when(options.output) {
             OutputType.RAW -> {
@@ -127,11 +145,8 @@ internal class ProgramAndVarsGen(
             "cx16" -> {
                 if(options.floats)
                     asmgen.out("  lda  #4 |  sta  $01")    // to use floats, make sure Basic rom is banked in
-                asmgen.out("  jsr  main.start |  lda  #4 |  sta  $01")
-                if(!options.noSysInit)
-                    asmgen.out("  jmp  ${compTarget.name}.cleanup_at_exit")
-                else
-                    asmgen.out("  rts")
+                asmgen.out("  jsr  main.start")
+                asmgen.out("  jmp  ${compTarget.name}.cleanup_at_exit")
             }
             "c64" -> {
                 asmgen.out("  jsr  main.start |  lda  #31 |  sta  $01")
@@ -155,23 +170,15 @@ internal class ProgramAndVarsGen(
     private fun memorySlabs() {
         asmgen.out("; memory slabs")
         asmgen.out("prog8_slabs\t.block")
-        for((name, info) in allocator.memorySlabs) {
-            if(info.second>1u)
-                asmgen.out("\t.align  ${info.second.toHex()}")
-            asmgen.out("$name\t.fill  ${info.first}")
+        for(slab in symboltable.allMemorySlabs) {
+            if(slab.align>1u)
+                asmgen.out("\t.align  ${slab.align.toHex()}")
+            asmgen.out("${slab.name}\t.fill  ${slab.size}")
         }
         asmgen.out("\t.bend")
     }
 
     private fun footer() {
-        // the global list of all floating point constants for the whole program
-        asmgen.out("; global float constants")
-        for (flt in allocator.globalFloatConsts) {
-            val floatFill = compTarget.machine.getFloat(flt.key).makeFloatFillAsm()
-            val floatvalue = flt.key
-            asmgen.out("${flt.value}\t.byte  $floatFill  ; float $floatvalue")
-        }
-
         // program end
         asmgen.out("prog8_program_end\t; end of program label for progend()")
     }
@@ -209,9 +216,9 @@ internal class ProgramAndVarsGen(
         if(!options.dontReinitGlobals) {
             // generate subroutine to initialize block-level (global) variables
             if (initializers.isNotEmpty()) {
-                asmgen.out("prog8_init_vars\t.proc\n")
+                asmgen.out("prog8_init_vars\t.block\n")
                 initializers.forEach { assign -> asmgen.translate(assign) }
-                asmgen.out("  rts\n  .pend")
+                asmgen.out("  rts\n  .bend")
             }
         }
 
@@ -263,17 +270,27 @@ internal class ProgramAndVarsGen(
 
         asmgen.out("")
 
+        val asmStartScope: String
+        val asmEndScope: String
+        if(sub.definingBlock.options().contains("force_output")) {
+            asmStartScope = ".block"
+            asmEndScope = ".bend"
+        } else {
+            asmStartScope = ".proc"
+            asmEndScope = ".pend"
+        }
+
         if(sub.isAsmSubroutine) {
             if(sub.asmAddress!=null)
                 return  // already done at the memvars section
 
             // asmsub with most likely just an inline asm in it
-            asmgen.out("${sub.name}\t.proc")
+            asmgen.out("${sub.name}\t$asmStartScope")
             sub.statements.forEach { asmgen.translate(it) }
-            asmgen.out("  .pend\n")
+            asmgen.out("  $asmEndScope\n")
         } else {
             // regular subroutine
-            asmgen.out("${sub.name}\t.proc")
+            asmgen.out("${sub.name}\t$asmStartScope")
 
             val scope = symboltable.lookupOrElse(sub.scopedName) { throw AssemblyError("lookup") }
             require(scope.type==StNodeType.SUBROUTINE)
@@ -302,7 +319,7 @@ internal class ProgramAndVarsGen(
                 asmgen.out("; simple int arg(s) passed via register(s)")
                 if(sub.parameters.size==1) {
                     val dt = sub.parameters[0].type
-                    val target = AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, dt, sub, variableAsmName = sub.parameters[0].name)
+                    val target = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, dt, sub, variableAsmName = sub.parameters[0].name)
                     if(dt in ByteDatatypes)
                         asmgen.assignRegister(RegisterOrPair.A, target)
                     else
@@ -310,8 +327,8 @@ internal class ProgramAndVarsGen(
                 } else {
                     require(sub.parameters.size==2)
                     // 2 simple byte args, first in A, second in Y
-                    val target1 = AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, sub.parameters[0].type, sub, variableAsmName = sub.parameters[0].name)
-                    val target2 = AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, sub.parameters[1].type, sub, variableAsmName = sub.parameters[1].name)
+                    val target1 = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, sub.parameters[0].type, sub, variableAsmName = sub.parameters[0].name)
+                    val target2 = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, sub.parameters[1].type, sub, variableAsmName = sub.parameters[1].name)
                     asmgen.assignRegister(RegisterOrPair.A, target1)
                     asmgen.assignRegister(RegisterOrPair.Y, target2)
                 }
@@ -350,7 +367,7 @@ internal class ProgramAndVarsGen(
                 .map { it.value as StStaticVariable }
             nonZpVariables2asm(variables)
 
-            asmgen.out("  .pend\n")
+            asmgen.out("  $asmEndScope\n")
         }
     }
 
@@ -432,9 +449,9 @@ internal class ProgramAndVarsGen(
         val result = mutableListOf<ZpStringWithInitial>()
         val vars = allocator.zeropageVars.filter { it.value.dt==DataType.STR }
         for (variable in vars) {
-            val svar = symboltable.lookup(variable.key) as StStaticVariable        // TODO faster in flat lookup table
-            if(svar.initialStringValue!=null)
-                result.add(ZpStringWithInitial(variable.key, variable.value, svar.initialStringValue!!))
+            val svar = symboltable.flat.getValue(variable.key) as StStaticVariable
+            if(svar.onetimeInitializationStringValue!=null)
+                result.add(ZpStringWithInitial(variable.key, variable.value, svar.onetimeInitializationStringValue!!))
         }
         return result
     }
@@ -443,9 +460,9 @@ internal class ProgramAndVarsGen(
         val result = mutableListOf<ZpArrayWithInitial>()
         val vars = allocator.zeropageVars.filter { it.value.dt in ArrayDatatypes }
         for (variable in vars) {
-            val svar = symboltable.lookup(variable.key) as StStaticVariable        // TODO faster in flat lookup table
-            if(svar.initialArrayValue!=null)
-                result.add(ZpArrayWithInitial(variable.key, variable.value, svar.initialArrayValue!!))
+            val svar = symboltable.flat.getValue(variable.key) as StStaticVariable
+            if(svar.onetimeInitializationArrayValue!=null)
+                result.add(ZpArrayWithInitial(variable.key, variable.value, svar.onetimeInitializationArrayValue!!))
         }
         return result
     }
@@ -464,7 +481,7 @@ internal class ProgramAndVarsGen(
         asmgen.out("; non-zeropage variables")
         val (stringvars, othervars) = variables.partition { it.dt==DataType.STR }
         stringvars.forEach {
-            outputStringvar(it.name, it.initialStringValue!!.second, it.initialStringValue!!.first)
+            outputStringvar(it.name, it.onetimeInitializationStringValue!!.second, it.onetimeInitializationStringValue!!.first)
         }
         othervars.sortedBy { it.type }.forEach {
             staticVariable2asm(it)
@@ -474,11 +491,11 @@ internal class ProgramAndVarsGen(
     private fun staticVariable2asm(variable: StStaticVariable) {
         val name = variable.name
         val initialValue: Number =
-            if(variable.initialNumericValue!=null) {
+            if(variable.onetimeInitializationNumericValue!=null) {
                 if(variable.dt== DataType.FLOAT)
-                    variable.initialNumericValue!!
+                    variable.onetimeInitializationNumericValue!!
                 else
-                    variable.initialNumericValue!!.toInt()
+                    variable.onetimeInitializationNumericValue!!.toInt()
             } else 0
 
         when (variable.dt) {
@@ -490,14 +507,14 @@ internal class ProgramAndVarsGen(
                 if(initialValue==0) {
                     asmgen.out("$name\t.byte  0,0,0,0,0  ; float")
                 } else {
-                    val floatFill = compTarget.machine.getFloat(initialValue).makeFloatFillAsm()
+                    val floatFill = compTarget.machine.getFloatAsmBytes(initialValue)
                     asmgen.out("$name\t.byte  $floatFill  ; float $initialValue")
                 }
             }
             DataType.STR -> {
                 throw AssemblyError("all string vars should have been interned into prog")
             }
-            in ArrayDatatypes -> arrayVariable2asm(name, variable.dt, variable.initialArrayValue, variable.length)
+            in ArrayDatatypes -> arrayVariable2asm(name, variable.dt, variable.onetimeInitializationArrayValue, variable.length)
             else -> {
                 throw AssemblyError("weird dt")
             }
@@ -549,7 +566,7 @@ internal class ProgramAndVarsGen(
             DataType.ARRAY_F -> {
                 val array = value ?: zeroFilledArray(orNumberOfZeros!!)
                 val floatFills = array.map {
-                    compTarget.machine.getFloat(it.number!!).makeFloatFillAsm()
+                    compTarget.machine.getFloatAsmBytes(it.number!!)
                 }
                 asmgen.out(varname)
                 for (f in array.zip(floatFills))
@@ -589,7 +606,7 @@ internal class ProgramAndVarsGen(
     }
 
     private fun outputStringvar(varname: String, encoding: Encoding, value: String) {
-        asmgen.out("$varname\t; $encoding:\"${value.escape().replace("\u0000", "<NULL>")}\"")
+        asmgen.out("$varname\t; $encoding:\"${value.escape().replace("\u0000", "<NULL>")}\"", false)
         val bytes = compTarget.encodeString(value, encoding).plus(0.toUByte())
         val outputBytes = bytes.map { "$" + it.toString(16).padStart(2, '0') }
         for (chunk in outputBytes.chunked(16))

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

@@ -15,8 +15,6 @@ internal class VariableAllocator(private val symboltable: SymbolTable,
 ) {
 
     private val zeropage = options.compTarget.machine.zeropage
-    private val memorySlabsInternal = mutableMapOf<String, Pair<UInt, UInt>>()
-    internal val memorySlabs: Map<String, Pair<UInt, UInt>> = memorySlabsInternal
     internal val globalFloatConsts = mutableMapOf<Double, String>()     // all float values in the entire program (value -> varname)
     internal val zeropageVars: Map<List<String>, Zeropage.ZpAllocation> = zeropage.allocatedVariables
 
@@ -24,12 +22,6 @@ internal class VariableAllocator(private val symboltable: SymbolTable,
         allocateZeropageVariables()
     }
 
-    internal fun getMemorySlab(name: String) = memorySlabsInternal[name]
-
-    internal fun allocateMemorySlab(name: String, size: UInt, align: UInt) {
-        memorySlabsInternal[name] = Pair(size, align)
-    }
-
     internal fun isZpVar(scopedName: List<String>) = scopedName in zeropage.allocatedVariables
 
     internal fun getFloatAsmConst(number: Double): String {
@@ -116,9 +108,9 @@ internal class VariableAllocator(private val symboltable: SymbolTable,
             }
         }
 
-        println("  number of allocated vars: $numberOfAllocatableVariables")
-        println("  put into zeropage: $numVariablesAllocatedInZP,  non-zp allocatable: ${numberOfNonIntegerVariables+numberOfExplicitNonZpVariables}")
-        println("  zeropage free space: ${zeropage.free.size} bytes")
+//        println("  number of allocated vars: $numberOfAllocatableVariables")
+//        println("  put into zeropage: $numVariablesAllocatedInZP,  non-zp allocatable: ${numberOfNonIntegerVariables+numberOfExplicitNonZpVariables}")
+//        println("  zeropage free space: ${zeropage.free.size} bytes")
     }
 
     private fun collectAllVariables(st: SymbolTable): Collection<StStaticVariable> {

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

@@ -2,7 +2,10 @@ package prog8.codegen.cpu6502.assignment
 
 import prog8.ast.Program
 import prog8.ast.expressions.*
-import prog8.ast.statements.*
+import prog8.ast.statements.AssignTarget
+import prog8.ast.statements.Assignment
+import prog8.ast.statements.DirectMemoryWrite
+import prog8.ast.statements.Subroutine
 import prog8.code.core.*
 import prog8.codegen.cpu6502.AsmGen
 
@@ -26,7 +29,6 @@ internal enum class SourceStorageKind {
 }
 
 internal class AsmAssignTarget(val kind: TargetStorageKind,
-                               private val program: Program,
                                private val asmgen: AsmGen,
                                val datatype: DataType,
                                val scope: Subroutine?,
@@ -37,7 +39,6 @@ internal class AsmAssignTarget(val kind: TargetStorageKind,
                                val origAstTarget: AssignTarget? = null
                                )
 {
-    val constMemoryAddress by lazy { memory?.addressExpression?.constValue(program)?.number?.toUInt() ?: 0u}
     val constArrayIndexValue by lazy { array?.indexer?.constIndex()?.toUInt() }
     val asmVarname: String by lazy {
         if (array == null)
@@ -68,28 +69,28 @@ internal class AsmAssignTarget(val kind: TargetStorageKind,
                                 if(reg.statusflag!=null)
                                     throw AssemblyError("can't assign value to processor statusflag directly")
                                 else
-                                    return AsmAssignTarget(TargetStorageKind.REGISTER, program, asmgen, dt, assign.definingSubroutine, register=reg.registerOrPair, origAstTarget = this)
+                                    return AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, dt, assign.definingSubroutine, register=reg.registerOrPair, origAstTarget = this)
                             }
                         }
-                        return AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, dt, assign.definingSubroutine, variableAsmName = asmgen.asmVariableName(identifier!!), origAstTarget =  this)
+                        return AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, dt, assign.definingSubroutine, variableAsmName = asmgen.asmVariableName(identifier!!), origAstTarget =  this)
                     }
-                    arrayindexed != null -> return AsmAssignTarget(TargetStorageKind.ARRAY, program, asmgen, dt, assign.definingSubroutine, array = arrayindexed, origAstTarget =  this)
-                    memoryAddress != null -> return AsmAssignTarget(TargetStorageKind.MEMORY, program, asmgen, dt, assign.definingSubroutine, memory =  memoryAddress, origAstTarget =  this)
+                    arrayindexed != null -> return AsmAssignTarget(TargetStorageKind.ARRAY, asmgen, dt, assign.definingSubroutine, array = arrayindexed, origAstTarget =  this)
+                    memoryAddress != null -> return AsmAssignTarget(TargetStorageKind.MEMORY, asmgen, dt, assign.definingSubroutine, memory =  memoryAddress, origAstTarget =  this)
                     else -> throw AssemblyError("weird target")
                 }
             }
         }
 
-        fun fromRegisters(registers: RegisterOrPair, signed: Boolean, scope: Subroutine?, program: Program, asmgen: AsmGen): AsmAssignTarget =
+        fun fromRegisters(registers: RegisterOrPair, signed: Boolean, scope: Subroutine?, asmgen: AsmGen): AsmAssignTarget =
                 when(registers) {
                     RegisterOrPair.A,
                     RegisterOrPair.X,
-                    RegisterOrPair.Y -> AsmAssignTarget(TargetStorageKind.REGISTER, program, asmgen, if(signed) DataType.BYTE else DataType.UBYTE, scope, register = registers)
+                    RegisterOrPair.Y -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, if(signed) DataType.BYTE else DataType.UBYTE, scope, register = registers)
                     RegisterOrPair.AX,
                     RegisterOrPair.AY,
-                    RegisterOrPair.XY -> AsmAssignTarget(TargetStorageKind.REGISTER, program, asmgen, if(signed) DataType.WORD else DataType.UWORD, scope, register = registers)
+                    RegisterOrPair.XY -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, if(signed) DataType.WORD else DataType.UWORD, scope, register = registers)
                     RegisterOrPair.FAC1,
-                    RegisterOrPair.FAC2 -> AsmAssignTarget(TargetStorageKind.REGISTER, program, asmgen, DataType.FLOAT, scope, register = registers)
+                    RegisterOrPair.FAC2 -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, DataType.FLOAT, scope, register = registers)
                     RegisterOrPair.R0,
                     RegisterOrPair.R1,
                     RegisterOrPair.R2,
@@ -105,7 +106,7 @@ internal class AsmAssignTarget(val kind: TargetStorageKind,
                     RegisterOrPair.R12,
                     RegisterOrPair.R13,
                     RegisterOrPair.R14,
-                    RegisterOrPair.R15 -> AsmAssignTarget(TargetStorageKind.REGISTER, program, asmgen, if(signed) DataType.WORD else DataType.UWORD, scope, register = registers)
+                    RegisterOrPair.R15 -> AsmAssignTarget(TargetStorageKind.REGISTER, asmgen, if(signed) DataType.WORD else DataType.UWORD, scope, register = registers)
                 }
     }
 }
@@ -122,9 +123,6 @@ internal class AsmAssignSource(val kind: SourceStorageKind,
                                val expression: Expression? = null
 )
 {
-    val constMemoryAddress by lazy { memory?.addressExpression?.constValue(program)?.number?.toUInt() ?: 0u}
-    val constArrayIndexValue by lazy { array?.indexer?.constIndex()?.toUInt() }
-
     val asmVarname: String
         get() = if(array==null)
             variableAsmName!!
@@ -132,8 +130,6 @@ internal class AsmAssignSource(val kind: SourceStorageKind,
             asmgen.asmVariableName(array.arrayvar)
 
     companion object {
-        fun fromAstSource(indexer: ArrayIndex, program: Program, asmgen: AsmGen): AsmAssignSource = fromAstSource(indexer.indexExpr, program, asmgen)
-
         fun fromAstSource(value: Expression, program: Program, asmgen: AsmGen): AsmAssignSource {
             val cv = value.constValue(program)
             if(cv!=null)

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

@@ -29,7 +29,7 @@ internal class AssignmentAsmGen(private val program: Program,
 
     internal fun virtualRegsToVariables(origtarget: AsmAssignTarget): AsmAssignTarget {
         return if(origtarget.kind==TargetStorageKind.REGISTER && origtarget.register in Cx16VirtualRegisters) {
-            AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, origtarget.datatype, origtarget.scope,
+            AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, origtarget.datatype, origtarget.scope,
                 variableAsmName = "cx16.${origtarget.register!!.name.lowercase()}", origAstTarget = origtarget.origAstTarget)
         } else origtarget
     }
@@ -72,6 +72,25 @@ internal class AssignmentAsmGen(private val program: Program,
                 val value = assign.source.array!!
                 val elementDt = assign.source.datatype
                 val arrayVarName = asmgen.asmVariableName(value.arrayvar)
+
+                val arrayVarDecl = value.arrayvar.targetVarDecl(program)!!
+                if(arrayVarDecl.datatype==DataType.UWORD) {
+                    // indexing a pointer var instead of a real array or string
+                    if(elementDt !in ByteDatatypes)
+                        throw AssemblyError("non-array var indexing requires bytes dt")
+                    if(value.inferType(program) isnot DataType.UBYTE)
+                        throw AssemblyError("non-array var indexing requires bytes index")
+                    asmgen.loadScaledArrayIndexIntoRegister(value, elementDt, CpuRegister.Y)
+                    if(asmgen.isZpVar(value.arrayvar)) {
+                        asmgen.out("  lda  ($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")
+                    }
+                    assignRegisterByte(assign.target, CpuRegister.A)
+                    return
+                }
+
                 val constIndex = value.indexer.constIndex()
                 if (constIndex!=null) {
                     // constant array index value
@@ -201,9 +220,25 @@ internal class AssignmentAsmGen(private val program: Program,
                             RegisterOrPair.A -> assignRegisterByte(assign.target, CpuRegister.A)
                             RegisterOrPair.X -> assignRegisterByte(assign.target, CpuRegister.X)
                             RegisterOrPair.Y -> assignRegisterByte(assign.target, CpuRegister.Y)
-                            RegisterOrPair.AX -> assignRegisterpairWord(assign.target, RegisterOrPair.AX)
-                            RegisterOrPair.AY -> assignRegisterpairWord(assign.target, RegisterOrPair.AY)
-                            RegisterOrPair.XY -> assignRegisterpairWord(assign.target, RegisterOrPair.XY)
+                            RegisterOrPair.AX -> assignVirtualRegister(assign.target, RegisterOrPair.AX)
+                            RegisterOrPair.AY -> assignVirtualRegister(assign.target, RegisterOrPair.AY)
+                            RegisterOrPair.XY -> assignVirtualRegister(assign.target, RegisterOrPair.XY)
+                            RegisterOrPair.R0 -> assignVirtualRegister(assign.target, RegisterOrPair.R0)
+                            RegisterOrPair.R1 -> assignVirtualRegister(assign.target, RegisterOrPair.R1)
+                            RegisterOrPair.R2 -> assignVirtualRegister(assign.target, RegisterOrPair.R2)
+                            RegisterOrPair.R3 -> assignVirtualRegister(assign.target, RegisterOrPair.R3)
+                            RegisterOrPair.R4 -> assignVirtualRegister(assign.target, RegisterOrPair.R4)
+                            RegisterOrPair.R5 -> assignVirtualRegister(assign.target, RegisterOrPair.R5)
+                            RegisterOrPair.R6 -> assignVirtualRegister(assign.target, RegisterOrPair.R6)
+                            RegisterOrPair.R7 -> assignVirtualRegister(assign.target, RegisterOrPair.R7)
+                            RegisterOrPair.R8 -> assignVirtualRegister(assign.target, RegisterOrPair.R8)
+                            RegisterOrPair.R9 -> assignVirtualRegister(assign.target, RegisterOrPair.R9)
+                            RegisterOrPair.R10 -> assignVirtualRegister(assign.target, RegisterOrPair.R10)
+                            RegisterOrPair.R11 -> assignVirtualRegister(assign.target, RegisterOrPair.R11)
+                            RegisterOrPair.R12 -> assignVirtualRegister(assign.target, RegisterOrPair.R12)
+                            RegisterOrPair.R13 -> assignVirtualRegister(assign.target, RegisterOrPair.R13)
+                            RegisterOrPair.R14 -> assignVirtualRegister(assign.target, RegisterOrPair.R14)
+                            RegisterOrPair.R15 -> assignVirtualRegister(assign.target, RegisterOrPair.R15)
                             else -> {
                                 val sflag = returnValue.second.statusflag
                                 if(sflag!=null)
@@ -263,7 +298,6 @@ internal class AssignmentAsmGen(private val program: Program,
                     "+" -> {}
                     "-" -> augmentableAsmGen.inplaceNegate(target, target.datatype)
                     "~" -> augmentableAsmGen.inplaceInvert(target, target.datatype)
-                    "not" -> augmentableAsmGen.inplaceBooleanNot(target, target.datatype)
                     else -> throw AssemblyError("invalid prefix operator")
                 }
             }
@@ -271,35 +305,8 @@ internal class AssignmentAsmGen(private val program: Program,
                 containmentCheckIntoA(value)
                 assignRegisterByte(assign.target, CpuRegister.A)
             }
-            is PipeExpression -> {
-                asmgen.translatePipeExpression(value.source, value.segments, value, false, false)
-                val resultDt = value.inferType(program)
-                val register =
-                    if(resultDt.isBytes) RegisterOrPair.A
-                    else if(resultDt.isWords) RegisterOrPair.AY
-                    else if(resultDt istype DataType.FLOAT) RegisterOrPair.FAC1
-                    else throw AssemblyError("invalid dt")
-                asmgen.assignRegister(register, assign.target)
-            }
             is BinaryExpression -> {
-                if(value.operator in ComparisonOperators) {
-                    // TODO real optimized code for comparison expressions that yield a boolean result value
-                    assignConstantByte(assign.target, 0)
-                    val origTarget = assign.target.origAstTarget
-                    if(origTarget!=null) {
-                        val assignTrue = AnonymousScope(mutableListOf(
-                            Assignment(origTarget, NumericLiteral.fromBoolean(true, assign.position), AssignmentOrigin.ASMGEN, assign.position)
-                        ), assign.position)
-                        val assignFalse = AnonymousScope(mutableListOf(), assign.position)
-                        val ifelse = IfElse(value.copy(), assignTrue, assignFalse, assign.position)
-                        ifelse.linkParents(value)
-                        asmgen.translate(ifelse)
-                    }
-                    else {
-                        // no orig ast assign target so can't use the workaround, so fallback to stack eval
-                        fallbackToStackEval(assign)
-                    }
-                } else {
+                if(!attemptAssignOptimizedBinexpr(value, assign)) {
                     // All remaining binary expressions just evaluate via the stack for now.
                     // (we can't use the assignment helper functions (assignExpressionTo...) to do it via registers here,
                     // because the code here is the implementation of exactly that...)
@@ -310,9 +317,400 @@ internal class AssignmentAsmGen(private val program: Program,
         }
     }
 
+    private fun assignVirtualRegister(target: AsmAssignTarget, register: RegisterOrPair) {
+        when(target.datatype) {
+            in ByteDatatypes -> {
+                asmgen.out("  lda  cx16.${register.toString().lowercase()}L")
+                assignRegisterByte(target, CpuRegister.A)
+            }
+            in WordDatatypes -> assignRegisterpairWord(target, register)
+            else -> throw AssemblyError("expected byte or word")
+        }
+    }
+
+    private fun attemptAssignOptimizedBinexpr(expr: BinaryExpression, assign: AsmAssignment): Boolean {
+        if(expr.operator in ComparisonOperators) {
+            if(expr.right.constValue(program)?.number == 0.0) {
+                if(expr.operator == "==" || expr.operator=="!=") {
+                    when(assign.target.datatype) {
+                        in ByteDatatypes -> if(attemptAssignToByteCompareZero(expr, assign)) return true
+                        else -> {
+                            // do nothing, this is handled by a type cast.
+                        }
+                    }
+                }
+            }
+            val origTarget = assign.target.origAstTarget
+            if(origTarget!=null) {
+                assignConstantByte(assign.target, 0)
+                val assignTrue = AnonymousScope(mutableListOf(
+                    Assignment(origTarget, NumericLiteral.fromBoolean(true, assign.position), AssignmentOrigin.ASMGEN, assign.position)
+                ), assign.position)
+                val assignFalse = AnonymousScope(mutableListOf(), assign.position)
+                val ifelse = IfElse(expr.copy(), assignTrue, assignFalse, assign.position)
+                ifelse.linkParents(expr)
+                asmgen.translate(ifelse)
+                return true
+            }
+        }
+
+        if(!expr.inferType(program).isInteger)
+            return false
+
+        if(expr.operator in setOf("&", "|", "^", "and", "or", "xor")) {
+            if(expr.left.inferType(program).isBytes && expr.right.inferType(program).isBytes &&
+                    expr.left.isSimple && expr.right.isSimple) {
+                if(expr.right is NumericLiteral || expr.right is IdentifierReference)
+                    assignLogicalWithSimpleRightOperandByte(assign.target, expr.left, expr.operator, expr.right)
+                else if(expr.left is NumericLiteral || expr.left is IdentifierReference)
+                    assignLogicalWithSimpleRightOperandByte(assign.target, expr.right, expr.operator, expr.left)
+                else {
+                    assignExpressionToRegister(expr.left, RegisterOrPair.A, false)
+                    asmgen.saveRegisterStack(CpuRegister.A, false)
+                    assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_B1", DataType.UBYTE, expr.definingSubroutine)
+                    asmgen.restoreRegisterStack(CpuRegister.A, false)
+                    when (expr.operator) {
+                        "&", "and" -> asmgen.out("  and  P8ZP_SCRATCH_B1")
+                        "|", "or" -> asmgen.out("  ora  P8ZP_SCRATCH_B1")
+                        "^", "xor" -> asmgen.out("  eor  P8ZP_SCRATCH_B1")
+                        else -> throw AssemblyError("invalid operator")
+                    }
+                    assignRegisterByte(assign.target, CpuRegister.A)
+                }
+                return true
+            }
+            if(expr.left.inferType(program).isWords && expr.right.inferType(program).isWords &&
+                    expr.left.isSimple && expr.right.isSimple) {
+                if(expr.right is NumericLiteral || expr.right is IdentifierReference)
+                    assignLogicalWithSimpleRightOperandWord(assign.target, expr.left, expr.operator, expr.right)
+                else if(expr.left is NumericLiteral || expr.left is IdentifierReference)
+                    assignLogicalWithSimpleRightOperandWord(assign.target, expr.right, expr.operator, expr.left)
+                else {
+                    assignExpressionToRegister(expr.left, RegisterOrPair.AY, false)
+                    asmgen.saveRegisterStack(CpuRegister.A, false)
+                    asmgen.saveRegisterStack(CpuRegister.Y, false)
+                    assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_W1", DataType.UWORD, expr.definingSubroutine)
+                    when (expr.operator) {
+                        "&", "and" -> asmgen.out("  pla |  and  P8ZP_SCRATCH_W1+1 |  tay |  pla |  and  P8ZP_SCRATCH_W1")
+                        "|", "or" -> asmgen.out("  pla |  ora  P8ZP_SCRATCH_W1+1 |  tay |  pla |  ora  P8ZP_SCRATCH_W1")
+                        "^", "xor" -> asmgen.out("  pla |  eor  P8ZP_SCRATCH_W1+1 |  tay |  pla |  eor  P8ZP_SCRATCH_W1")
+                        else -> throw AssemblyError("invalid operator")
+                    }
+                    assignRegisterpairWord(assign.target, RegisterOrPair.AY)
+                }
+                return true
+            }
+            return false
+        }
+
+        if(expr.operator == "==" || expr.operator == "!=") {
+            // expression datatype is BOOL (ubyte) but operands can be anything
+            if(expr.left.inferType(program).isBytes && expr.right.inferType(program).isBytes &&
+                    expr.left.isSimple && expr.right.isSimple) {
+                assignExpressionToRegister(expr.left, RegisterOrPair.A, false)
+                asmgen.saveRegisterStack(CpuRegister.A, false)
+                assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_B1", DataType.UBYTE, expr.definingSubroutine)
+                asmgen.restoreRegisterStack(CpuRegister.A, false)
+                if(expr.operator=="==") {
+                    asmgen.out("""
+                        cmp  P8ZP_SCRATCH_B1
+                        bne  +
+                        lda  #1
+                        bne  ++
++                       lda  #0
++""")
+                } else {
+                    asmgen.out("""
+                        cmp  P8ZP_SCRATCH_B1
+                        beq  +
+                        lda  #1
+                        bne  ++
++                       lda  #0
++""")
+                }
+                assignRegisterByte(assign.target, CpuRegister.A)
+                return true
+            } else if(expr.left.inferType(program).isWords && expr.right.inferType(program).isWords &&
+                    expr.left.isSimple && expr.right.isSimple) {
+                assignExpressionToRegister(expr.left, RegisterOrPair.AY, false)
+                asmgen.saveRegisterStack(CpuRegister.A, false)
+                asmgen.saveRegisterStack(CpuRegister.Y, false)
+                assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_W1", DataType.UWORD, expr.definingSubroutine)
+                asmgen.restoreRegisterStack(CpuRegister.Y, false)
+                asmgen.restoreRegisterStack(CpuRegister.A, false)
+                if(expr.operator=="==") {
+                    asmgen.out("""
+                        cmp  P8ZP_SCRATCH_W1
+                        bne  +
+                        cpy  P8ZP_SCRATCH_W1+1
+                        bne  +
+                        lda  #1
+                        bne  ++
++                       lda  #0
++""")
+                } else {
+                    asmgen.out("""
+                        cmp  P8ZP_SCRATCH_W1
+                        bne  +
+                        cpy  P8ZP_SCRATCH_W1+1
+                        bne  +
+                        lda  #0
+                        bne  ++
++                       lda  #1
++""")
+                }
+                assignRegisterByte(assign.target, CpuRegister.A)
+                return true
+            }
+            return false
+        }
+        else if(expr.operator=="+" || expr.operator=="-") {
+            val dt = expr.inferType(program).getOrElse { throw AssemblyError("invalid dt") }
+            val left = expr.left
+            val right = expr.right
+            if(dt in ByteDatatypes) {
+                when (right) {
+                    is IdentifierReference -> {
+                        assignExpressionToRegister(left, RegisterOrPair.A, dt==DataType.BYTE)
+                        val symname = asmgen.asmVariableName(right)
+                        if(expr.operator=="+")
+                            asmgen.out("  clc |  adc  $symname")
+                        else
+                            asmgen.out("  sec |  sbc  $symname")
+                        assignRegisterByte(assign.target, CpuRegister.A)
+                        return true
+                    }
+                    is NumericLiteral -> {
+                        assignExpressionToRegister(left, RegisterOrPair.A, dt==DataType.BYTE)
+                        if(expr.operator=="+")
+                            asmgen.out("  clc |  adc  #${right.number.toHex()}")
+                        else
+                            asmgen.out("  sec |  sbc  #${right.number.toHex()}")
+                        assignRegisterByte(assign.target, CpuRegister.A)
+                        return true
+                    }
+                    else -> return false
+                }
+            } else if(dt in WordDatatypes) {
+                when (right) {
+                    is AddressOf -> {
+                        assignExpressionToRegister(left, RegisterOrPair.AY, dt==DataType.WORD)
+                        val symbol = asmgen.asmVariableName(right.identifier)
+                        if(expr.operator=="+")
+                            asmgen.out("""
+                                clc
+                                adc  #<$symbol
+                                pha
+                                tya
+                                adc  #>$symbol
+                                tay
+                                pla""")
+                        else
+                            asmgen.out("""
+                                sec
+                                sbc  #<$symbol
+                                pha
+                                tya
+                                sbc  #>$symbol
+                                tay
+                                pla""")
+                        assignRegisterpairWord(assign.target, RegisterOrPair.AY)
+                        return true
+                    }
+                    is IdentifierReference -> {
+                        val symname = asmgen.asmVariableName(right)
+                        assignExpressionToRegister(left, RegisterOrPair.AY, dt==DataType.WORD)
+                        if(expr.operator=="+")
+                            asmgen.out("""
+                                clc
+                                adc  $symname
+                                pha
+                                tya
+                                adc  $symname+1
+                                tay
+                                pla""")
+                        else
+                            asmgen.out("""
+                                sec
+                                sbc  $symname
+                                pha
+                                tya
+                                sbc  $symname+1
+                                tay
+                                pla""")
+                        assignRegisterpairWord(assign.target, RegisterOrPair.AY)
+                        return true
+                    }
+                    is NumericLiteral -> {
+                        assignExpressionToRegister(left, RegisterOrPair.AY, dt==DataType.WORD)
+                        if(expr.operator=="+") {
+                            asmgen.out("""
+                                clc
+                                adc  #<${right.number.toHex()}
+                                pha
+                                tya
+                                adc  #>${right.number.toHex()}
+                                tay
+                                pla""")
+                        } else if(expr.operator=="-") {
+                            asmgen.out("""
+                                sec
+                                sbc  #<${right.number.toHex()}
+                                pha
+                                tya
+                                sbc  #>${right.number.toHex()}
+                                tay
+                                pla""")
+                        }
+                        assignRegisterpairWord(assign.target, RegisterOrPair.AY)
+                        return true
+                    }
+                    is TypecastExpression -> {
+                        val castedValue = right.expression
+                        if(right.type in WordDatatypes && castedValue.inferType(program).isBytes) {
+                            if(castedValue is IdentifierReference) {
+                                val castedSymname = asmgen.asmVariableName(castedValue)
+                                assignExpressionToRegister(left, RegisterOrPair.AY, dt==DataType.WORD)
+                                if(expr.operator=="+")
+                                    asmgen.out("""
+                                        clc
+                                        adc  $castedSymname
+                                        bcc  +
+                                        iny
+    +""")
+                                else
+                                    asmgen.out("""
+                                        sec
+                                        sbc  $castedSymname
+                                        bcs  +
+                                        dey
+    +""")
+                                assignRegisterpairWord(assign.target, RegisterOrPair.AY)
+                                return true
+                            }
+                        }
+                    }
+                    else -> return false
+                }
+            }
+        }
+        return false
+    }
+
+    private fun assignLogicalWithSimpleRightOperandByte(target: AsmAssignTarget, left: Expression, operator: String, right: Expression) {
+        assignExpressionToRegister(left, RegisterOrPair.A, false)
+        val operand = when(right) {
+            is NumericLiteral -> "#${right.number.toHex()}"
+            is IdentifierReference -> asmgen.asmSymbolName(right)
+            else -> throw AssemblyError("wrong right operand type")
+        }
+        when (operator) {
+            "&", "and" -> asmgen.out("  and  $operand")
+            "|", "or" -> asmgen.out("  ora  $operand")
+            "^", "xor" -> asmgen.out("  eor  $operand")
+            else -> throw AssemblyError("invalid operator")
+        }
+        assignRegisterByte(target, CpuRegister.A)
+    }
+
+    private fun assignLogicalWithSimpleRightOperandWord(target: AsmAssignTarget, left: Expression, operator: String, right: Expression) {
+        assignExpressionToRegister(left, RegisterOrPair.AY, false)
+        when(right) {
+            is NumericLiteral -> {
+                val number = right.number.toHex()
+                when (operator) {
+                    "&", "and" -> asmgen.out("  and  #<$number |  pha |  tya |  and  #>$number |  tay |  pla")
+                    "|", "or" -> asmgen.out("  ora  #<$number |  pha |  tya |  ora  #>$number |  tay |  pla")
+                    "^", "xor" -> asmgen.out("  eor  #<$number |  pha |  tya |  eor  #>$number |  tay |  pla")
+                    else -> throw AssemblyError("invalid operator")
+                }
+            }
+            is IdentifierReference -> {
+                val name = asmgen.asmSymbolName(right)
+                when (operator) {
+                    "&", "and" -> asmgen.out("  and  $name |  pha |  tya |  and  $name+1 |  tay |  pla")
+                    "|", "or" -> asmgen.out("  ora  $name |  pha |  tya |  ora  $name+1 |  tay |  pla")
+                    "^", "xor" -> asmgen.out("  eor  $name |  pha |  tya |  eor  $name+1 |  tay |  pla")
+                    else -> throw AssemblyError("invalid operator")
+                }
+            }
+            else -> throw AssemblyError("wrong right operand type")
+        }
+        assignRegisterpairWord(target, RegisterOrPair.AY)
+    }
+
+    private fun attemptAssignToByteCompareZero(expr: BinaryExpression, assign: AsmAssignment): Boolean {
+        when (expr.operator) {
+            "==" -> {
+                when(val dt = expr.left.inferType(program).getOrElse { throw AssemblyError("invalid dt") }) {
+                    in ByteDatatypes -> {
+                        assignExpressionToRegister(expr.left, RegisterOrPair.A, dt==DataType.BYTE)
+                        asmgen.out("""
+                            beq  +
+                            lda  #0
+                            beq  ++
++                           lda  #1
++""")
+                        assignRegisterByte(assign.target, CpuRegister.A)
+                        return true
+                    }
+                    in WordDatatypes -> {
+                        assignExpressionToRegister(expr.left, RegisterOrPair.AY, dt==DataType.WORD)
+                        asmgen.out("""
+                            sty  P8ZP_SCRATCH_B1
+                            ora  P8ZP_SCRATCH_B1
+                            beq  +
+                            lda  #0
+                            beq  ++
++                           lda  #1
++""")
+                        assignRegisterByte(assign.target, CpuRegister.A)
+                        return true
+                    }
+                    DataType.FLOAT -> {
+                        assignExpressionToRegister(expr.left, RegisterOrPair.FAC1, true)
+                        asmgen.out("  jsr  floats.SIGN |  and  #1 |  eor  #1")
+                        assignRegisterByte(assign.target, CpuRegister.A)
+                        return true
+                    }
+                    else->{
+                        return false
+                    }
+                }
+            }
+            "!=" -> {
+                when(val dt = expr.left.inferType(program).getOrElse { throw AssemblyError("invalid dt") }) {
+                    in ByteDatatypes -> {
+                        assignExpressionToRegister(expr.left, RegisterOrPair.A, dt==DataType.BYTE)
+                        asmgen.out("  beq  + |  lda  #1")
+                        asmgen.out("+")
+                        assignRegisterByte(assign.target, CpuRegister.A)
+                        return true
+                    }
+                    in WordDatatypes -> {
+                        assignExpressionToRegister(expr.left, RegisterOrPair.AY, dt==DataType.WORD)
+                        asmgen.out("  sty  P8ZP_SCRATCH_B1 |  ora  P8ZP_SCRATCH_B1")
+                        asmgen.out("  beq  + |  lda  #1")
+                        asmgen.out("+")
+                        assignRegisterByte(assign.target, CpuRegister.A)
+                        return true
+                    }
+                    DataType.FLOAT -> {
+                        assignExpressionToRegister(expr.left, RegisterOrPair.FAC1, true)
+                        asmgen.out("  jsr  floats.SIGN")
+                        assignRegisterByte(assign.target, CpuRegister.A)
+                        return true
+                    }
+                    else->{
+                        return false
+                    }
+                }
+            }
+            else -> return false
+        }
+    }
+
     private fun fallbackToStackEval(assign: AsmAssignment) {
-        // TODO DON'T STACK-EVAL... perhaps by using a temp var? so that it becomes augmentable assignment expression?
-        //      or don't try to solve it here in this one case and rather rewrite the whole stack based value evaluation.
         // this routine is called for assigning a binaryexpression value:
         // - if it's a boolean comparison expression and the workaround isn't possible (no origTarget ast node)
         // - for all other binary expressions.
@@ -336,7 +734,7 @@ internal class AssignmentAsmGen(private val program: Program,
                     val varname = asmgen.asmVariableName(containment.iterable as IdentifierReference)
                     assignExpressionToRegister(containment.element, RegisterOrPair.A, elementDt istype DataType.BYTE)
                     asmgen.saveRegisterLocal(CpuRegister.A, containment.definingSubroutine!!)
-                    assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W1"), varname)
+                    assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W1"), varname)
                     asmgen.restoreRegisterLocal(CpuRegister.A)
                     asmgen.out("  ldy  #${stringVal.value.length}")
                     asmgen.out("  jsr  prog8_lib.containment_bytearray")
@@ -355,14 +753,14 @@ internal class AssignmentAsmGen(private val program: Program,
                         in ByteDatatypes -> {
                             assignExpressionToRegister(containment.element, RegisterOrPair.A, elementDt istype DataType.BYTE)
                             asmgen.saveRegisterLocal(CpuRegister.A, containment.definingSubroutine!!)
-                            assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W1"), varname)
+                            assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W1"), varname)
                             asmgen.restoreRegisterLocal(CpuRegister.A)
                             asmgen.out("  ldy  #${arrayVal.value.size}")
                             asmgen.out("  jsr  prog8_lib.containment_bytearray")
                         }
                         in WordDatatypes -> {
                             assignExpressionToVariable(containment.element, "P8ZP_SCRATCH_W1", elementDt.getOr(DataType.UNDEFINED), containment.definingSubroutine)
-                            assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W2"), varname)
+                            assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W2"), varname)
                             asmgen.out("  ldy  #${arrayVal.value.size}")
                             asmgen.out("  jsr  prog8_lib.containment_wordarray")
                         }
@@ -379,7 +777,7 @@ internal class AssignmentAsmGen(private val program: Program,
                 // use subroutine
                 assignExpressionToRegister(containment.element, RegisterOrPair.A, elementDt istype DataType.BYTE)
                 asmgen.saveRegisterLocal(CpuRegister.A, containment.definingSubroutine!!)
-                assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W1"), varname)
+                assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W1"), varname)
                 asmgen.restoreRegisterLocal(CpuRegister.A)
                 val stringVal = variable.value as StringLiteral
                 asmgen.out("  ldy  #${stringVal.value.length}")
@@ -393,7 +791,7 @@ internal class AssignmentAsmGen(private val program: Program,
                 val arrayVal = variable.value as ArrayLiteral
                 assignExpressionToRegister(containment.element, RegisterOrPair.A, elementDt istype DataType.BYTE)
                 asmgen.saveRegisterLocal(CpuRegister.A, containment.definingSubroutine!!)
-                assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W1"), varname)
+                assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W1"), varname)
                 asmgen.restoreRegisterLocal(CpuRegister.A)
                 asmgen.out("  ldy  #${arrayVal.value.size}")
                 asmgen.out("  jsr  prog8_lib.containment_bytearray")
@@ -402,7 +800,7 @@ internal class AssignmentAsmGen(private val program: Program,
             DataType.ARRAY_W, DataType.ARRAY_UW -> {
                 val arrayVal = variable.value as ArrayLiteral
                 assignExpressionToVariable(containment.element, "P8ZP_SCRATCH_W1", elementDt.getOr(DataType.UNDEFINED), containment.definingSubroutine)
-                assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W2"), varname)
+                assignAddressOf(AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, DataType.UWORD, containment.definingSubroutine, "P8ZP_SCRATCH_W2"), varname)
                 asmgen.out("  ldy  #${arrayVal.value.size}")
                 asmgen.out("  jsr  prog8_lib.containment_wordarray")
                 return
@@ -513,10 +911,10 @@ internal class AssignmentAsmGen(private val program: Program,
             return
         }
 
-        if(origTypeCastExpression.type == DataType.UBYTE) {
+        if(valueDt in WordDatatypes && origTypeCastExpression.type == DataType.UBYTE) {
             val parentTc = origTypeCastExpression.parent as? TypecastExpression
             if(parentTc!=null && parentTc.type==DataType.UWORD) {
-                // typecast something to ubyte and directly back to uword
+                // typecast a word value to ubyte and directly back to uword
                 // generate code for lsb(value) here instead of the ubyte typecast
                 return assignCastViaLsbFunc(value, target)
             }
@@ -566,6 +964,23 @@ internal class AssignmentAsmGen(private val program: Program,
                 assignTypeCastedFloatFAC1("P8ZP_SCRATCH_W1", target.datatype)
                 assignVariableToRegister("P8ZP_SCRATCH_W1", target.register!!, target.datatype in SignedDatatypes)
             } else {
+                if(!(valueDt isAssignableTo targetDt)) {
+                    if(valueDt in WordDatatypes && targetDt in ByteDatatypes) {
+                        // word to byte, just take the lsb
+                        return assignCastViaLsbFunc(value, target)
+                    } else if(valueDt in WordDatatypes && targetDt in WordDatatypes) {
+                        // word to word, just assign
+                        assignExpressionToRegister(value, target.register!!, targetDt==DataType.BYTE || targetDt==DataType.WORD)
+                    } else if(valueDt in ByteDatatypes && targetDt in ByteDatatypes) {
+                        // byte to byte, just assign
+                        assignExpressionToRegister(value, target.register!!, targetDt==DataType.BYTE || targetDt==DataType.WORD)
+                    } else if(valueDt in ByteDatatypes && targetDt in WordDatatypes) {
+                        // byte to word, just assign
+                        assignExpressionToRegister(value, target.register!!, targetDt==DataType.WORD)
+                    }
+                    else
+                        throw AssemblyError("can't cast $valueDt to $targetDt, this should have been checked in the astchecker")
+                }
                 assignExpressionToRegister(value, target.register!!, targetDt==DataType.BYTE || targetDt==DataType.WORD)
             }
             return
@@ -634,7 +1049,7 @@ internal class AssignmentAsmGen(private val program: Program,
         when(sourceDt) {
             DataType.UBYTE -> {
                 when(targetDt) {
-                    DataType.UBYTE, DataType.BYTE -> {
+                    DataType.BYTE -> {
                         asmgen.out("  lda  $sourceAsmVarName |  sta  $targetAsmVarName")
                     }
                     DataType.UWORD, DataType.WORD -> {
@@ -657,7 +1072,7 @@ internal class AssignmentAsmGen(private val program: Program,
             }
             DataType.BYTE -> {
                 when(targetDt) {
-                    DataType.UBYTE, DataType.BYTE -> {
+                    DataType.UBYTE -> {
                         asmgen.out("  lda  $sourceAsmVarName |  sta  $targetAsmVarName")
                     }
                     DataType.UWORD -> {
@@ -687,7 +1102,7 @@ internal class AssignmentAsmGen(private val program: Program,
                     DataType.BYTE, DataType.UBYTE -> {
                         asmgen.out("  lda  $sourceAsmVarName |  sta  $targetAsmVarName")
                     }
-                    DataType.WORD, DataType.UWORD -> {
+                    DataType.WORD -> {
                         asmgen.out("  lda  $sourceAsmVarName |  sta  $targetAsmVarName |  lda  $sourceAsmVarName+1 |  sta  $targetAsmVarName+1")
                     }
                     DataType.FLOAT -> {
@@ -708,7 +1123,7 @@ internal class AssignmentAsmGen(private val program: Program,
                     DataType.BYTE, DataType.UBYTE -> {
                         asmgen.out("  lda  $sourceAsmVarName |  sta  $targetAsmVarName")
                     }
-                    DataType.WORD, DataType.UWORD -> {
+                    DataType.UWORD -> {
                         asmgen.out("  lda  $sourceAsmVarName |  sta  $targetAsmVarName |  lda  $sourceAsmVarName+1 |  sta  $targetAsmVarName+1")
                     }
                     DataType.FLOAT -> {
@@ -749,7 +1164,7 @@ internal class AssignmentAsmGen(private val program: Program,
         when(sourceDt) {
             DataType.UBYTE -> {
                 when(targetDt) {
-                    DataType.UBYTE, DataType.BYTE -> {
+                    DataType.BYTE -> {
                         asmgen.out("  st${regs.toString().lowercase()}  $targetAsmVarName")
                     }
                     DataType.UWORD, DataType.WORD -> {
@@ -783,7 +1198,7 @@ internal class AssignmentAsmGen(private val program: Program,
             }
             DataType.BYTE -> {
                 when(targetDt) {
-                    DataType.UBYTE, DataType.BYTE -> {
+                    DataType.UBYTE -> {
                         asmgen.out("  st${regs.toString().lowercase()}  $targetAsmVarName")
                     }
                     DataType.UWORD -> {
@@ -830,7 +1245,7 @@ internal class AssignmentAsmGen(private val program: Program,
                     DataType.BYTE, DataType.UBYTE -> {
                         asmgen.out("  st${regs.toString().lowercase().first()}  $targetAsmVarName")
                     }
-                    DataType.WORD, DataType.UWORD -> {
+                    DataType.WORD -> {
                         when(regs) {
                             RegisterOrPair.AX -> asmgen.out("  sta  $targetAsmVarName |  stx  $targetAsmVarName+1")
                             RegisterOrPair.AY -> asmgen.out("  sta  $targetAsmVarName |  sty  $targetAsmVarName+1")
@@ -858,7 +1273,7 @@ internal class AssignmentAsmGen(private val program: Program,
                     DataType.BYTE, DataType.UBYTE -> {
                         asmgen.out("  st${regs.toString().lowercase().first()}  $targetAsmVarName")
                     }
-                    DataType.WORD, DataType.UWORD -> {
+                    DataType.UWORD -> {
                         when(regs) {
                             RegisterOrPair.AX -> asmgen.out("  sta  $targetAsmVarName |  stx  $targetAsmVarName+1")
                             RegisterOrPair.AY -> asmgen.out("  sta  $targetAsmVarName |  sty  $targetAsmVarName+1")
@@ -1365,6 +1780,22 @@ internal class AssignmentAsmGen(private val program: Program,
                 storeRegisterAInMemoryAddress(target.memory!!)
             }
             TargetStorageKind.ARRAY -> {
+                if(target.origAstTarget?.arrayindexed?.arrayvar?.targetVarDecl(program)?.datatype==DataType.UWORD) {
+                    // assigning an indexed pointer var
+                    if (target.constArrayIndexValue==0u) {
+                        asmgen.out("  lda  $sourceName")
+                        asmgen.storeAIntoPointerVar(target.origAstTarget.arrayindexed!!.arrayvar)
+                    } else {
+                        asmgen.loadScaledArrayIndexIntoRegister(target.array!!, DataType.UBYTE, CpuRegister.Y)
+                        if (asmgen.isZpVar(target.origAstTarget.arrayindexed!!.arrayvar)) {
+                            asmgen.out("  lda  $sourceName |  sta  (${target.asmVarname}),y")
+                        } else {
+                            asmgen.out("  lda  ${target.asmVarname} |  sta  P8ZP_SCRATCH_W2 |  lda  ${target.asmVarname}+1 |  sta  P8ZP_SCRATCH_W2+1")
+                            asmgen.out("  lda  $sourceName |  sta  (P8ZP_SCRATCH_W2),y")
+                        }
+                    }
+                    return
+                }
                 if (target.constArrayIndexValue!=null) {
                     val scaledIdx = target.constArrayIndexValue!! * program.memsizer.memorySize(target.datatype).toUInt()
                     asmgen.out(" lda  $sourceName  | sta  ${target.asmVarname}+$scaledIdx")
@@ -1897,6 +2328,22 @@ internal class AssignmentAsmGen(private val program: Program,
                     storeRegisterAInMemoryAddress(target.memory!!)
                 }
                 TargetStorageKind.ARRAY -> {
+                    if(target.origAstTarget?.arrayindexed?.arrayvar?.targetVarDecl(program)?.datatype==DataType.UWORD) {
+                        // assigning an indexed pointer var
+                        if (target.constArrayIndexValue==0u) {
+                            asmgen.out("  lda  #0")
+                            asmgen.storeAIntoPointerVar(target.origAstTarget.arrayindexed!!.arrayvar)
+                        } else {
+                            asmgen.loadScaledArrayIndexIntoRegister(target.array!!, DataType.UBYTE, CpuRegister.Y)
+                            if (asmgen.isZpVar(target.origAstTarget.arrayindexed!!.arrayvar)) {
+                                asmgen.out("  lda  #0 |  sta  (${target.asmVarname}),y")
+                            } else {
+                                asmgen.out("  lda  ${target.asmVarname} |  sta  P8ZP_SCRATCH_W2 |  lda  ${target.asmVarname}+1 |  sta  P8ZP_SCRATCH_W2+1")
+                                asmgen.out("  lda  #0 |  sta  (P8ZP_SCRATCH_W2),y")
+                            }
+                        }
+                        return
+                    }
                     if (target.constArrayIndexValue!=null) {
                         val indexValue = target.constArrayIndexValue!!
                         asmgen.out("  stz  ${target.asmVarname}+$indexValue")
@@ -1915,10 +2362,7 @@ internal class AssignmentAsmGen(private val program: Program,
                     RegisterOrPair.XY -> asmgen.out("  ldx  #0 |  ldy  #0")
                     RegisterOrPair.FAC1, RegisterOrPair.FAC2 -> throw AssemblyError("expected typecasted byte to float")
                     in Cx16VirtualRegisters -> {
-                        asmgen.out(
-                            "  stz  cx16.${
-                                target.register.toString().lowercase()
-                            } |  stz  cx16.${target.register.toString().lowercase()}+1")
+                        asmgen.out("  stz  cx16.${target.register.toString().lowercase()} |  stz  cx16.${target.register.toString().lowercase()}+1")
                     }
                     else -> throw AssemblyError("weird register")
                 }
@@ -1940,13 +2384,29 @@ internal class AssignmentAsmGen(private val program: Program,
                 storeRegisterAInMemoryAddress(target.memory!!)
             }
             TargetStorageKind.ARRAY -> {
+                if(target.origAstTarget?.arrayindexed?.arrayvar?.targetVarDecl(program)?.datatype==DataType.UWORD) {
+                    // assigning an indexed pointer var
+                    if (target.constArrayIndexValue==0u) {
+                        asmgen.out("  lda  #${byte.toHex()}")
+                        asmgen.storeAIntoPointerVar(target.origAstTarget.arrayindexed!!.arrayvar)
+                    } else {
+                        asmgen.loadScaledArrayIndexIntoRegister(target.array!!, DataType.UBYTE, CpuRegister.Y)
+                        if (asmgen.isZpVar(target.origAstTarget.arrayindexed!!.arrayvar)) {
+                            asmgen.out("  lda  #${byte.toHex()} |  sta  (${target.asmVarname}),y")
+                        } else {
+                            asmgen.out("  lda  ${target.asmVarname} |  sta  P8ZP_SCRATCH_W2 |  lda  ${target.asmVarname}+1 |  sta  P8ZP_SCRATCH_W2+1")
+                            asmgen.out("  lda  #${byte.toHex()} |  sta  (P8ZP_SCRATCH_W2),y")
+                        }
+                    }
+                    return
+                }
                 if (target.constArrayIndexValue!=null) {
                     val indexValue = target.constArrayIndexValue!!
                     asmgen.out("  lda  #${byte.toHex()} |  sta  ${target.asmVarname}+$indexValue")
                 }
                 else {
                     asmgen.loadScaledArrayIndexIntoRegister(target.array!!, DataType.UBYTE, CpuRegister.Y)
-                    asmgen.out("  lda  #<${byte.toHex()} |  sta  ${target.asmVarname},y")
+                    asmgen.out("  lda  #${byte.toHex()} |  sta  ${target.asmVarname},y")
                 }
             }
             TargetStorageKind.REGISTER -> when(target.register!!) {
@@ -2295,7 +2755,7 @@ internal class AssignmentAsmGen(private val program: Program,
 
     internal fun assignExpressionToRegister(expr: Expression, register: RegisterOrPair, signed: Boolean) {
         val src = AsmAssignSource.fromAstSource(expr, program, asmgen)
-        val tgt = AsmAssignTarget.fromRegisters(register, signed, null, program, asmgen)
+        val tgt = AsmAssignTarget.fromRegisters(register, signed, null, asmgen)
         val assign = AsmAssignment(src, tgt, false, program.memsizer, expr.position)
         translateNormalAssignment(assign)
     }
@@ -2305,14 +2765,14 @@ internal class AssignmentAsmGen(private val program: Program,
             throw AssemblyError("can't directly assign a FLOAT expression to an integer variable $expr")
         } else {
             val src = AsmAssignSource.fromAstSource(expr, program, asmgen)
-            val tgt = AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, dt, scope, variableAsmName = asmVarName)
+            val tgt = AsmAssignTarget(TargetStorageKind.VARIABLE, asmgen, dt, scope, variableAsmName = asmVarName)
             val assign = AsmAssignment(src, tgt, false, program.memsizer, expr.position)
             translateNormalAssignment(assign)
         }
     }
 
     internal fun assignVariableToRegister(asmVarName: String, register: RegisterOrPair, signed: Boolean) {
-        val tgt = AsmAssignTarget.fromRegisters(register, signed, null, program, asmgen)
+        val tgt = AsmAssignTarget.fromRegisters(register, signed, null, asmgen)
         val src = AsmAssignSource(SourceStorageKind.VARIABLE, program, asmgen, tgt.datatype, variableAsmName = asmVarName)
         val assign = AsmAssignment(src, tgt, false, program.memsizer, Position.DUMMY)
         translateNormalAssignment(assign)

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

@@ -28,7 +28,6 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     "+" -> {}
                     "-" -> inplaceNegate(target, type)
                     "~" -> inplaceInvert(target, type)
-                    "not" -> inplaceBooleanNot(target, type)
                     else -> throw AssemblyError("invalid prefix operator")
                 }
             }
@@ -237,7 +236,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     }
                     else -> {
                         // TODO use some other evaluation here; don't use the estack to transfer the address to read/write from
-                        asmgen.assignExpressionTo(memory.addressExpression, AsmAssignTarget(TargetStorageKind.STACK, program, asmgen, DataType.UWORD, memory.definingSubroutine))
+                        asmgen.assignExpressionTo(memory.addressExpression, AsmAssignTarget(TargetStorageKind.STACK, asmgen, DataType.UWORD, memory.definingSubroutine))
                         asmgen.out("  jsr  prog8_lib.read_byte_from_address_on_stack |  sta  P8ZP_SCRATCH_B1")
                         when {
                             valueLv != null -> inplaceModification_byte_litval_to_variable("P8ZP_SCRATCH_B1", DataType.UBYTE, operator, valueLv.toInt())
@@ -306,7 +305,6 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                                         AsmAssignTarget.fromRegisters(
                                             RegisterOrPair.A,
                                             target.datatype == DataType.BYTE, null,
-                                            program,
                                             asmgen
                                         )
                                     val assign = AsmAssignment(target.origAssign.source, tgt, false, program.memsizer, value.position)
@@ -318,7 +316,6 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                                         AsmAssignTarget.fromRegisters(
                                             RegisterOrPair.AY,
                                             target.datatype == DataType.WORD, null,
-                                            program,
                                             asmgen
                                         )
                                     val assign = AsmAssignment(target.origAssign.source, tgt, false, program.memsizer, value.position)
@@ -330,7 +327,6 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                                         AsmAssignTarget.fromRegisters(
                                             RegisterOrPair.FAC1,
                                             true, null,
-                                            program,
                                             asmgen
                                         )
                                     val assign = AsmAssignment(target.origAssign.source, tgt, false, program.memsizer, value.position)
@@ -391,9 +387,9 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     bne  -
 +""")
             }
-            "&", "and" -> asmgen.out(" and  P8ZP_SCRATCH_B1")
-            "|", "or" -> asmgen.out(" ora  P8ZP_SCRATCH_B1")
-            "^", "xor" -> asmgen.out(" eor  P8ZP_SCRATCH_B1")
+            "&" -> asmgen.out(" and  P8ZP_SCRATCH_B1")
+            "|" -> asmgen.out(" ora  P8ZP_SCRATCH_B1")
+            "^" -> asmgen.out(" eor  P8ZP_SCRATCH_B1")
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
         asmgen.storeAIntoZpPointerVar(sourceName)
@@ -428,9 +424,9 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                         bne  -
 +""")
             }
-            "&", "and" -> asmgen.out(" and  $otherName")
-            "|", "or" -> asmgen.out(" ora  $otherName")
-            "^", "xor" -> asmgen.out(" eor  $otherName")
+            "&" -> asmgen.out(" and  $otherName")
+            "|" -> asmgen.out(" ora  $otherName")
+            "^" -> asmgen.out(" eor  $otherName")
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
         asmgen.storeAIntoZpPointerVar(sourceName)
@@ -485,17 +481,17 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     asmgen.storeAIntoZpPointerVar(sourceName)
                 }
             }
-            "&", "and" -> {
+            "&" -> {
                 val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
                 asmgen.out("  and  #$value")
                 asmgen.storeAIntoZpPointerVar(sourceName)
             }
-            "|", "or" -> {
+            "|"-> {
                 val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
                 asmgen.out("  ora  #$value")
                 asmgen.storeAIntoZpPointerVar(sourceName)
             }
-            "^", "xor" -> {
+            "^" -> {
                 val sourceName = asmgen.loadByteFromPointerIntoA(pointervar)
                 asmgen.out("  eor  #$value")
                 asmgen.storeAIntoZpPointerVar(sourceName)
@@ -563,15 +559,15 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
 +""")
                 }
             }
-            "&", "and" -> {
+            "&" -> {
                 asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
                 asmgen.out("  and  $name |  sta  $name")
             }
-            "|", "or" -> {
+            "|" -> {
                 asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
                 asmgen.out("  ora  $name |  sta  $name")
             }
-            "^", "xor" -> {
+            "^" -> {
                 asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
                 asmgen.out("  eor  $name |  sta  $name")
             }
@@ -649,9 +645,9 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
 +""")
                 }
             }
-            "&", "and" -> asmgen.out(" lda  $name |  and  $otherName |  sta  $name")
-            "|", "or" -> asmgen.out(" lda  $name |  ora  $otherName |  sta  $name")
-            "^", "xor" -> asmgen.out(" lda  $name |  eor  $otherName |  sta  $name")
+            "&" -> asmgen.out(" lda  $name |  and  $otherName |  sta  $name")
+            "|" -> asmgen.out(" lda  $name |  ora  $otherName |  sta  $name")
+            "^" -> asmgen.out(" lda  $name |  eor  $otherName |  sta  $name")
             "==" -> {
                 asmgen.out("""
                     lda  $otherName
@@ -740,9 +736,9 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     }
                 }
             }
-            "&", "and" -> asmgen.out(" lda  $name |  and  #$value |  sta  $name")
-            "|", "or" -> asmgen.out(" lda  $name |  ora  #$value |  sta  $name")
-            "^", "xor" -> asmgen.out(" lda  $name |  eor  #$value |  sta  $name")
+            "&" -> asmgen.out(" lda  $name |  and  #$value |  sta  $name")
+            "|" -> asmgen.out(" lda  $name |  ora  #$value |  sta  $name")
+            "^" -> asmgen.out(" lda  $name |  eor  #$value |  sta  $name")
             "==" -> {
                 asmgen.out("""
                     lda  $name
@@ -785,15 +781,15 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     sbc  P8ZP_SCRATCH_B1
                     sta  $name""")
             }
-            "|", "or" -> {
+            "|" -> {
                 asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("  ora  $name  |  sta  $name")
             }
-            "&", "and" -> {
+            "&" -> {
                 asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("  and  $name  |  sta  $name")
             }
-            "^", "xor" -> {
+            "^" -> {
                 asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("  eor  $name  |  sta  $name")
             }
@@ -828,11 +824,11 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     dec  $name+1
 +""")
             }
-            "|", "or" -> {
+            "|" -> {
                 asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("  ora  $name  |  sta  $name")
             }
-            "&", "and" -> {
+            "&" -> {
                 asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("  and  $name  |  sta  $name")
                 if(dt in WordDatatypes) {
@@ -842,7 +838,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                         asmgen.out("  lda  #0 |  sta  $name+1")
                 }
             }
-            "^", "xor" -> {
+            "^" -> {
                 asmgen.translateDirectMemReadExpressionToRegAorStack(memread, false)
                 asmgen.out("  eor  $name  |  sta  $name")
             }
@@ -1059,7 +1055,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     }
                 }
             }
-            "&", "and" -> {
+            "&" -> {
                 when {
                     value == 0 -> {
                         if(asmgen.isTargetCpu(CpuType.CPU65c02))
@@ -1096,7 +1092,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     else -> asmgen.out("  lda  $name |  and  #<$value |  sta  $name |  lda  $name+1 |  and  #>$value |  sta  $name+1")
                 }
             }
-            "|", "or" -> {
+            "|" -> {
                 when {
                     value == 0 -> {}
                     value and 255 == 0 -> asmgen.out("  lda  $name+1 |  ora  #>$value |  sta  $name+1")
@@ -1104,7 +1100,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     else -> asmgen.out("  lda  $name |  ora  #<$value |  sta  $name |  lda  $name+1 |  ora  #>$value |  sta  $name+1")
                 }
             }
-            "^", "xor" -> {
+            "^" -> {
                 when {
                     value == 0 -> {}
                     value and 255 == 0 -> asmgen.out("  lda  $name+1 |  eor  #>$value |  sta  $name+1")
@@ -1268,7 +1264,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
 +""")
                         }
                     }
-                    "&", "and" -> {
+                    "&" -> {
                         asmgen.out("  lda  $otherName |  and  $name |  sta  $name")
                         if(dt in WordDatatypes) {
                             if(asmgen.isTargetCpu(CpuType.CPU65c02))
@@ -1277,8 +1273,8 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                                 asmgen.out("  lda  #0 |  sta  $name+1")
                         }
                     }
-                    "|", "or" -> asmgen.out("  lda  $otherName |  ora  $name |  sta  $name")
-                    "^", "xor" -> asmgen.out("  lda  $otherName |  eor  $name |  sta  $name")
+                    "|" -> asmgen.out("  lda  $otherName |  ora  $name |  sta  $name")
+                    "^" -> asmgen.out("  lda  $otherName |  eor  $name |  sta  $name")
                     else -> throw AssemblyError("invalid operator for in-place modification $operator")
                 }
             }
@@ -1349,9 +1345,9 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                         """)
                     }
                     "<<", ">>" -> throw AssemblyError("shift by a word value not supported, max is a byte")
-                    "&", "and" -> asmgen.out(" lda  $name |  and  $otherName |  sta  $name |  lda  $name+1 |  and  $otherName+1 |  sta  $name+1")
-                    "|", "or" -> asmgen.out(" lda  $name |  ora  $otherName |  sta  $name |  lda  $name+1 |  ora  $otherName+1 |  sta  $name+1")
-                    "^", "xor" -> asmgen.out(" lda  $name |  eor  $otherName |  sta  $name |  lda  $name+1 |  eor  $otherName+1 |  sta  $name+1")
+                    "&" -> asmgen.out(" lda  $name |  and  $otherName |  sta  $name |  lda  $name+1 |  and  $otherName+1 |  sta  $name+1")
+                    "|" -> asmgen.out(" lda  $name |  ora  $otherName |  sta  $name |  lda  $name+1 |  ora  $otherName+1 |  sta  $name+1")
+                    "^" -> asmgen.out(" lda  $name |  eor  $otherName |  sta  $name |  lda  $name+1 |  eor  $otherName+1 |  sta  $name+1")
                     else -> throw AssemblyError("invalid operator for in-place modification $operator")
                 }
             }
@@ -1521,7 +1517,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                             bne  -
 +""")
                     }
-                    "&", "and" -> {
+                    "&" -> {
                         asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
                         asmgen.out("  and  $name |  sta  $name")
                         if(dt in WordDatatypes) {
@@ -1531,11 +1527,11 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                                 asmgen.out("  lda  #0 |  sta  $name+1")
                         }
                     }
-                    "|", "or" -> {
+                    "|" -> {
                         asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
                         asmgen.out("  ora  $name |  sta  $name")
                     }
-                    "^", "xor" -> {
+                    "^" -> {
                         asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
                         asmgen.out("  eor  $name |  sta  $name")
                     }
@@ -1567,15 +1563,15 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                         remainderVarByWordInAY()
                     }
                     "<<", ">>" -> throw AssemblyError("shift by a word value not supported, max is a byte")
-                    "&", "and" -> {
+                    "&" -> {
                         asmgen.assignExpressionToRegister(value, RegisterOrPair.AY)
                         asmgen.out("  and  $name |  sta  $name |  tya |  and  $name+1 |  sta  $name+1")
                     }
-                    "|", "or" -> {
+                    "|" -> {
                         asmgen.assignExpressionToRegister(value, RegisterOrPair.AY)
                         asmgen.out("  ora  $name |  sta  $name |  tya |  ora  $name+1 |  sta  $name+1")
                     }
-                    "^", "xor" -> {
+                    "^" -> {
                         asmgen.assignExpressionToRegister(value, RegisterOrPair.AY)
                         asmgen.out("  eor  $name |  sta  $name |  tya |  eor  $name+1 |  sta  $name+1")
                     }
@@ -1800,136 +1796,6 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
         }
     }
 
-    internal fun inplaceBooleanNot(target: AsmAssignTarget, dt: DataType) {
-        when (dt) {
-            DataType.UBYTE -> {
-                when (target.kind) {
-                    TargetStorageKind.VARIABLE -> {
-                        asmgen.out("""
-                            lda  ${target.asmVarname}
-                            beq  +
-                            lda  #1
-+                           eor  #1
-                            sta  ${target.asmVarname}""")
-                    }
-                    TargetStorageKind.MEMORY -> {
-                        val mem = target.memory!!
-                        when (mem.addressExpression) {
-                            is NumericLiteral -> {
-                                val addr = (mem.addressExpression as NumericLiteral).number.toHex()
-                                asmgen.out("""
-                                    lda  $addr
-                                    beq  +
-                                    lda  #1
-+                                   eor  #1
-                                    sta  $addr""")
-                            }
-                            is IdentifierReference -> {
-                                val sourceName = asmgen.loadByteFromPointerIntoA(mem.addressExpression as IdentifierReference)
-                                asmgen.out("""
-                                    beq  +
-                                    lda  #1
-+                                   eor  #1""")
-                                asmgen.storeAIntoZpPointerVar(sourceName)
-                            }
-                            else -> {
-                                asmgen.assignExpressionToVariable(mem.addressExpression, "P8ZP_SCRATCH_W2", DataType.UWORD, target.scope)
-                                asmgen.loadAFromZpPointerVar("P8ZP_SCRATCH_W2")
-                                asmgen.out("""
-                                    beq  +
-                                    lda  #1
-+                                   eor  #1""")
-                                asmgen.storeAIntoZpPointerVar("P8ZP_SCRATCH_W2")
-                            }
-                        }
-                    }
-                    TargetStorageKind.REGISTER -> {
-                        when(target.register!!) {
-                            RegisterOrPair.A -> asmgen.out("""
-                                cmp  #0
-                                beq  +
-                                lda  #1
-+                               eor  #1""")
-                            RegisterOrPair.X -> asmgen.out("""
-                                txa
-                                beq  +
-                                lda  #1
-+                               eor  #1
-                                tax""")
-                            RegisterOrPair.Y -> asmgen.out("""
-                                tya
-                                beq  +
-                                lda  #1
-+                               eor  #1
-                                tay""")
-                            else -> throw AssemblyError("invalid reg dt for byte not")
-                        }
-                    }
-                    TargetStorageKind.STACK -> TODO("no asm gen for byte stack not")
-                    else -> throw AssemblyError("no asm gen for in-place not of ubyte ${target.kind}")
-                }
-            }
-            DataType.UWORD -> {
-                when (target.kind) {
-                    TargetStorageKind.VARIABLE -> {
-                        asmgen.out("""
-                            lda  ${target.asmVarname}
-                            ora  ${target.asmVarname}+1
-                            beq  +
-                            lda  #1
-+                           eor  #1
-                            sta  ${target.asmVarname}
-                            lsr  a
-                            sta  ${target.asmVarname}+1""")
-                    }
-                    TargetStorageKind.REGISTER -> {
-                        when(target.register!!) {
-                            RegisterOrPair.AX -> {
-                                asmgen.out("""
-                                    stx  P8ZP_SCRATCH_REG
-                                    ora  P8ZP_SCRATCH_REG
-                                    beq  +
-                                    lda  #0
-                                    tax
-                                    beq  ++
-        +                           lda  #1
-        +""")
-                            }
-                            RegisterOrPair.AY -> {
-                                asmgen.out("""
-                                    sty  P8ZP_SCRATCH_REG
-                                    ora  P8ZP_SCRATCH_REG
-                                    beq  +
-                                    lda  #0
-                                    tay
-                                    beq  ++
-        +                           lda  #1
-        +""")
-                            }
-                            RegisterOrPair.XY -> {
-                                asmgen.out("""
-                                    stx  P8ZP_SCRATCH_REG
-                                    tya
-                                    ora  P8ZP_SCRATCH_REG
-                                    beq  +
-                                    ldy  #0
-                                    ldx  #0
-                                    beq  ++
-        +                           ldx  #1
-        +""")
-                            }
-                            in Cx16VirtualRegisters -> throw AssemblyError("cx16 virtual regs should be variables, not real registers")
-                            else -> throw AssemblyError("invalid reg dt for word not")
-                        }
-                    }
-                    TargetStorageKind.STACK -> TODO("no asm gen for word stack not")
-                    else -> throw AssemblyError("no asm gen for in-place not of uword for ${target.kind}")
-                }
-            }
-            else -> throw AssemblyError("boolean-not of invalid type")
-        }
-    }
-
     internal fun inplaceInvert(target: AsmAssignTarget, dt: DataType) {
         when (dt) {
             DataType.UBYTE -> {

codeGenExperimental/build.gradle

@@ -24,11 +24,12 @@ compileTestKotlin {
 }
 
 dependencies {
-    implementation project(':codeAst')
     implementation project(':codeCore')
+    implementation project(':intermediate')
+    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:1.1.14"
+    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.16"
 
 }
 

codeGenExperimental/codeGenExperimental.iml

@@ -10,7 +10,8 @@
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="library" name="KotlinJavaRuntime" level="project" />
     <orderEntry type="library" name="michael.bull.kotlin.result.jvm" level="project" />
-    <orderEntry type="module" module-name="codeAst" />
+    <orderEntry type="module" module-name="codeGenIntermediate" />
+    <orderEntry type="module" module-name="intermediate" />
     <orderEntry type="module" module-name="codeCore" />
   </component>
 </module>

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

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

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

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

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

@@ -1,666 +0,0 @@
-package prog8.codegen.experimental
-
-import prog8.code.*
-import prog8.code.ast.*
-import prog8.code.core.*
-import javax.xml.stream.XMLOutputFactory
-import kotlin.io.path.Path
-import kotlin.io.path.absolutePathString
-import kotlin.io.path.div
-
-/*
-
-    NOTE: The goal is to keep the dependencies as lean as possible! For now, we depend only on:
-         - codeAst (the 'lean' new AST and the SymbolTable)
-         - codeCore (various base enums and interfaces)
-
-    This *should* be enough to build a complete code generator with. But we'll see :)
-
- */
-
-
-class AstToXmlConverter(internal val program: PtProgram,
-                        internal val symbolTable: SymbolTable,
-                        internal val options: CompilationOptions
-) {
-
-    private lateinit var xml: IndentingXmlWriter
-
-    fun writeXml() {
-        val writer = (options.outputDir / Path(program.name+"-ast.xml")).toFile().printWriter()
-        xml = IndentingXmlWriter(XMLOutputFactory.newFactory().createXMLStreamWriter(writer))
-        xml.doc()
-        xml.elt("program")
-        xml.attr("name", program.name)
-        xml.startChildren()
-        writeOptions(options)
-        program.children.forEach { writeNode(it) }
-        writeSymboltable(symbolTable)
-        xml.endElt()
-        xml.endDoc()
-        xml.close()
-    }
-
-    private fun writeSymboltable(st: SymbolTable) {
-        xml.elt("symboltable")
-        xml.startChildren()
-        st.flat.forEach{ (name, entry) ->
-            xml.elt("entry")
-            xml.attr("name", name.joinToString("."))
-            xml.attr("type", entry.type.name)
-            xml.startChildren()
-            writeStNode(entry)
-            xml.endElt()
-        }
-        xml.endElt()
-    }
-
-    private fun writeStNode(node: StNode) {
-        when(node.type) {
-            StNodeType.GLOBAL,
-            StNodeType.LABEL,
-            StNodeType.BLOCK,
-            StNodeType.BUILTINFUNC,
-            StNodeType.SUBROUTINE -> {/* no additional info*/}
-            StNodeType.ROMSUB -> {
-                node as StRomSub
-                xml.elt("romsub")
-                xml.attr("address", node.address.toString())
-                xml.endElt()
-            }
-            StNodeType.STATICVAR -> {
-                node as StStaticVariable
-                xml.elt("var")
-                xml.attr("type", node.dt.name)
-                xml.attr("zpwish", node.zpwish.name)
-                if(node.length!=null)
-                    xml.attr("length", node.length.toString())
-                if(node.initialNumericValue!=null || node.initialArrayValue!=null || node.initialStringValue!=null) {
-                    xml.startChildren()
-                    if(node.initialNumericValue!=null) {
-                        writeNumber(node.dt, node.initialNumericValue!!)
-                    }
-                    if(node.initialStringValue!=null) {
-                        xml.writeTextNode(
-                            "string",
-                            listOf(Pair("encoding", node.initialStringValue!!.second.name)),
-                            node.initialStringValue!!.first,
-                            false
-                        )
-                    }
-                    if(node.initialArrayValue!=null) {
-                        xml.elt("array")
-                        xml.startChildren()
-                        val eltDt = ArrayToElementTypes.getValue(node.dt)
-                        node.initialArrayValue!!.forEach {
-                            if(it.number!=null) {
-                                writeNumber(eltDt, it.number!!)
-                            }
-                            if(it.addressOf!=null) {
-                                xml.elt("addressof")
-                                xml.attr("symbol", it.addressOf!!.joinToString("."))
-                                xml.endElt()
-                            }
-                        }
-                        xml.endElt()
-                    }
-                }
-                xml.endElt()
-            }
-            StNodeType.MEMVAR -> {
-                node as StMemVar
-                xml.writeTextNode("memvar",
-                    listOf(Pair("type", node.dt.name)),
-                    node.address.toString(),
-                    false)
-            }
-            StNodeType.CONSTANT -> {
-                node as StConstant
-                xml.writeTextNode("const",
-                    listOf(Pair("type", node.dt.name)),
-                    intOrDouble(node.dt, node.value).toString(),
-                    false)
-            }
-        }
-    }
-
-    private fun writeOptions(options: CompilationOptions) {
-        xml.elt("options")
-        xml.attr("target", options.compTarget.name)
-        xml.attr("output", options.output.name)
-        xml.attr("launcher", options.launcher.name)
-        xml.attr("zeropage", options.zeropage.name)
-        xml.attr("loadaddress", options.loadAddress.toString())
-        xml.attr("floatsenabled", options.floats.toString())
-        xml.attr("nosysinit", options.noSysInit.toString())
-        xml.attr("dontreinitglobals", options.dontReinitGlobals.toString())
-        xml.attr("optimize", options.optimize.toString())
-        if(options.zpReserved.isNotEmpty()) {
-            xml.startChildren()
-            options.zpReserved.forEach {
-                xml.elt("zpreserved")
-                xml.attr("from", it.first.toString())
-                xml.attr("to", it.last.toString())
-                xml.endElt()
-            }
-        }
-        xml.endElt()
-    }
-
-    private fun writeNode(it: PtNode) {
-        when(it) {
-            is PtBlock -> write(it)
-            is PtSub -> write(it)
-            is PtVariable -> write(it)
-            is PtAssignment -> write(it)
-            is PtConstant -> write(it)
-            is PtAsmSub -> write(it)
-            is PtAddressOf -> write(it)
-            is PtArrayIndexer -> write(it)
-            is PtArray -> write(it)
-            is PtBinaryExpression -> write(it)
-            is PtBuiltinFunctionCall -> write(it)
-            is PtConditionalBranch -> write(it)
-            is PtContainmentCheck -> write(it)
-            is PtForLoop -> write(it)
-            is PtFunctionCall -> write(it)
-            is PtIdentifier -> write(it)
-            is PtIfElse -> write(it)
-            is PtInlineAssembly -> write(it)
-            is PtIncludeBinary -> write(it)
-            is PtJump -> write(it)
-            is PtMemoryByte -> write(it)
-            is PtMemMapped -> write(it)
-            is PtNumber -> write(it)
-            is PtPipe -> write(it)
-            is PtPostIncrDecr -> write(it)
-            is PtPrefix -> write(it)
-            is PtRange -> write(it)
-            is PtRepeatLoop -> write(it)
-            is PtReturn -> write(it)
-            is PtString -> write(it)
-            is PtTypeCast -> write(it)
-            is PtWhen -> write(it)
-            is PtWhenChoice -> write(it)
-            is PtLabel -> write(it)
-            is PtNop -> {}
-            is PtBreakpoint -> write(it)
-            is PtScopeVarsDecls -> write(it)
-            is PtNodeGroup -> it.children.forEach { writeNode(it) }
-            else -> TODO("$it")
-        }
-    }
-
-    private fun write(vars: PtScopeVarsDecls) {
-        xml.elt("vars")
-        xml.startChildren()
-        vars.children.forEach { writeNode(it) }
-        xml.endElt()
-    }
-
-    private fun write(breakPt: PtBreakpoint) {
-        xml.elt("breakpoint")
-        xml.pos(breakPt.position)
-        xml.endElt()
-    }
-
-    private fun write(pipe: PtPipe) {
-        xml.elt("pipe")
-        xml.attr("type", pipe.type.name)
-        xml.startChildren()
-        pipe.children.forEach { writeNode(it) }
-        xml.endElt()
-    }
-
-    private fun write(array: PtArray) {
-        xml.elt("array")
-        xml.attr("type", array.type.name)
-        xml.startChildren()
-        array.children.forEach { writeNode(it) }
-        xml.endElt()
-    }
-
-    private fun write(prefix: PtPrefix) {
-        xml.elt("prefix")
-        xml.attr("op", prefix.operator)
-        xml.attr("type", prefix.type.name)
-        xml.startChildren()
-        xml.elt("value")
-        xml.startChildren()
-        writeNode(prefix.value)
-        xml.endElt()
-        xml.endElt()
-    }
-
-    private fun write(string: PtString) =
-        xml.writeTextNode("string", listOf(Pair("encoding", string.encoding.name)), string.value, false)
-
-    private fun write(rept: PtRepeatLoop) {
-        xml.elt("repeat")
-        xml.pos(rept.position)
-        xml.startChildren()
-        xml.elt("count")
-        xml.startChildren()
-        writeNode(rept.count)
-        xml.endElt()
-        writeNode(rept.statements)
-        xml.endElt()
-    }
-
-    private fun write(branch: PtConditionalBranch) {
-        xml.elt("conditionalbranch")
-        xml.attr("condition", branch.condition.name)
-        xml.pos(branch.position)
-        xml.startChildren()
-        xml.elt("true")
-        xml.startChildren()
-        writeNode(branch.trueScope)
-        xml.endElt()
-        if(branch.falseScope.children.isNotEmpty()) {
-            xml.elt("false")
-            xml.startChildren()
-            writeNode(branch.falseScope)
-            xml.endElt()
-        }
-        xml.endElt()
-    }
-
-    private fun write(check: PtContainmentCheck) {
-        xml.elt("containment")
-        xml.attr("type", check.type.name)
-        xml.startChildren()
-        xml.elt("element")
-        xml.startChildren()
-        writeNode(check.children[0])
-        xml.endElt()
-        xml.elt("iterable")
-        xml.startChildren()
-        writeNode(check.children[1])
-        xml.endElt()
-        xml.endElt()
-    }
-
-    private fun write(range: PtRange) {
-        xml.elt("range")
-        xml.attr("type", range.type.name)
-        xml.startChildren()
-        xml.elt("from")
-        xml.startChildren()
-        writeNode(range.from)
-        xml.endElt()
-        xml.elt("to")
-        xml.startChildren()
-        writeNode(range.to)
-        xml.endElt()
-        xml.elt("step")
-        xml.startChildren()
-        writeNode(range.step)
-        xml.endElt()
-        xml.endElt()
-    }
-
-    private fun write(forLoop: PtForLoop) {
-        xml.elt("for")
-        xml.attr("loopvar", strTargetName(forLoop.variable))
-        xml.pos(forLoop.position)
-        xml.startChildren()
-        xml.elt("iterable")
-        xml.startChildren()
-        writeNode(forLoop.iterable)
-        xml.endElt()
-        writeNode(forLoop.statements)
-        xml.endElt()
-    }
-
-    private fun write(membyte: PtMemoryByte) {
-        xml.elt("membyte")
-        xml.attr("type", membyte.type.name)
-        xml.startChildren()
-        xml.elt("address")
-        xml.startChildren()
-        writeNode(membyte.address)
-        xml.endElt()
-        xml.endElt()
-    }
-
-    private fun write(whenStmt: PtWhen) {
-        xml.elt("when")
-        xml.pos(whenStmt.position)
-        xml.startChildren()
-        xml.elt("value")
-        xml.startChildren()
-        writeNode(whenStmt.value)
-        xml.endElt()
-        xml.elt("choices")
-        xml.startChildren()
-        writeNode(whenStmt.choices)
-        xml.endElt()
-        xml.endElt()
-    }
-
-    private fun write(choice: PtWhenChoice) {
-        xml.elt("choice")
-        if(choice.isElse) {
-            xml.attr("else", "true")
-            xml.startChildren()
-        } else {
-            xml.startChildren()
-            xml.elt("values")
-            xml.startChildren()
-            writeNode(choice.values)
-            xml.endElt()
-        }
-        writeNode(choice.statements)
-        xml.endElt()
-    }
-
-    private fun write(inlineAsm: PtInlineAssembly) {
-        xml.elt("assembly")
-        xml.pos(inlineAsm.position)
-        xml.startChildren()
-        xml.writeTextNode("code", emptyList(), inlineAsm.assembly)
-        xml.endElt()
-    }
-
-    private fun write(inlineBinary: PtIncludeBinary) {
-        xml.elt("binary")
-        xml.attr("filename", inlineBinary.file.absolutePathString())
-        if(inlineBinary.offset!=null)
-            xml.attr("offset", inlineBinary.offset!!.toString())
-        if(inlineBinary.length!=null)
-            xml.attr("length", inlineBinary.length!!.toString())
-        xml.pos(inlineBinary.position)
-        xml.endElt()
-    }
-
-    private fun write(fcall: PtBuiltinFunctionCall) {
-        xml.elt("builtinfcall")
-        xml.attr("name", fcall.name)
-        if(fcall.void)
-            xml.attr("type", "VOID")
-        else
-            xml.attr("type", fcall.type.name)
-        xml.startChildren()
-        fcall.children.forEach { writeNode(it) }
-        xml.endElt()
-    }
-
-    private fun write(cast: PtTypeCast) {
-        xml.elt("cast")
-        xml.attr("type", cast.type.name)
-        xml.startChildren()
-        writeNode(cast.value)
-        xml.endElt()
-    }
-
-    private fun write(aix: PtArrayIndexer) {
-        xml.elt("arrayindexed")
-        xml.attr("type", aix.type.name)
-        xml.startChildren()
-        write(aix.variable)
-        writeNode(aix.index)
-        xml.endElt()
-    }
-
-    private fun write(binexpr: PtBinaryExpression) {
-        xml.elt("binexpr")
-        xml.attr("op", binexpr.operator)
-        xml.attr("type", binexpr.type.name)
-        xml.startChildren()
-        writeNode(binexpr.left)
-        writeNode(binexpr.right)
-        xml.endElt()
-    }
-
-    private fun write(addrof: PtAddressOf) {
-        xml.elt("addressof")
-        xml.attr("symbol", strTargetName(addrof.identifier))
-        xml.endElt()
-    }
-
-    private fun write(fcall: PtFunctionCall) {
-        xml.elt("fcall")
-        xml.attr("name", strTargetName(fcall))
-        if(fcall.void)
-            xml.attr("type", "VOID")
-        else
-            xml.attr("type", fcall.type.name)
-        xml.pos(fcall.position)
-        xml.startChildren()
-        fcall.children.forEach { writeNode(it) }
-        xml.endElt()
-    }
-
-    private fun write(number: PtNumber) = writeNumber(number.type, number.number)
-
-    private fun writeNumber(type: DataType, number: Double) =
-        xml.writeTextNode("number", listOf(Pair("type", type.name)), intOrDouble(type, number).toString(), false)
-
-    private fun write(symbol: PtIdentifier) {
-        xml.elt("symbol")
-        xml.attr("name", strTargetName(symbol))
-        xml.attr("type", symbol.type.name)
-        xml.endElt()
-    }
-
-    private fun write(assign: PtAssignment) {
-        xml.elt("assign")
-        xml.pos(assign.position)
-        xml.startChildren()
-        write(assign.target)
-        writeNode(assign.value)
-        xml.endElt()
-    }
-
-    private fun write(ifElse: PtIfElse) {
-        xml.elt("ifelse")
-        xml.pos(ifElse.position)
-        xml.startChildren()
-        xml.elt("condition")
-        xml.startChildren()
-        writeNode(ifElse.condition)
-        xml.endElt()
-        xml.elt("true")
-        xml.pos(ifElse.ifScope.position)
-        xml.startChildren()
-        writeNode(ifElse.ifScope)
-        xml.endElt()
-        if(ifElse.elseScope.children.isNotEmpty()) {
-            xml.elt("false")
-            xml.pos(ifElse.elseScope.position)
-            xml.startChildren()
-            writeNode(ifElse.elseScope)
-            xml.endElt()
-        }
-        xml.endElt()
-    }
-
-    private fun write(ret: PtReturn) {
-        xml.elt("return")
-        if(ret.hasValue) {
-            xml.startChildren()
-            writeNode(ret.value!!)
-        }
-        xml.endElt()
-    }
-
-    private fun write(incdec: PtPostIncrDecr) {
-        if(incdec.operator=="++") xml.elt("inc") else xml.elt("dec")
-        xml.startChildren()
-        write(incdec.target)
-        xml.endElt()
-    }
-
-    private fun write(label: PtLabel) {
-        xml.elt("label")
-        xml.attr("name", label.scopedName.joinToString("."))
-        xml.pos(label.position)
-        xml.endElt()
-    }
-
-    private fun write(block: PtBlock) {
-        xml.elt("block")
-        xml.attr("name", block.scopedName.joinToString("."))
-        if(block.address!=null)
-            xml.attr("address", block.address!!.toString())
-        xml.attr("library", block.library.toString())
-        xml.pos(block.position)
-        xml.startChildren()
-        block.children.forEach { writeNode(it) }
-        xml.endElt()
-    }
-
-    private fun write(memMapped: PtMemMapped) {
-        xml.writeTextNode("memvar",
-            listOf(
-                Pair("name", memMapped.scopedName.joinToString(".")),
-                Pair("type", memMapped.type.name)
-            ),
-            memMapped.address.toString(),
-            false)
-    }
-
-    private fun write(target: PtAssignTarget) {
-        xml.elt("target")
-        xml.startChildren()
-        if(target.identifier!=null) {
-            writeNode(target.identifier!!)
-        } else if(target.memory!=null) {
-            writeNode(target.memory!!)
-        } else if(target.array!=null) {
-            writeNode(target.array!!)
-        } else
-            throw InternalCompilerException("weird assign target")
-        xml.endElt()
-    }
-
-    private fun write(jump: PtJump) {
-        xml.elt("jump")
-        if(jump.identifier!=null) xml.attr("symbol", strTargetName(jump.identifier!!))
-        else if(jump.address!=null) xml.attr("address", jump.address!!.toString())
-        else if(jump.generatedLabel!=null) xml.attr("label", jump.generatedLabel!!)
-        else
-            throw InternalCompilerException("weird jump target")
-        xml.endElt()
-    }
-
-    private fun write(sub: PtSub) {
-        xml.elt("sub")
-        xml.attr("name", sub.scopedName.joinToString("."))
-        if(sub.inline)
-            xml.attr("inline", "true")
-        xml.attr("returntype", sub.returntype?.toString() ?: "VOID")
-        xml.pos(sub.position)
-        xml.startChildren()
-        if(sub.parameters.isNotEmpty()) {
-            xml.elt("parameters")
-            xml.startChildren()
-            sub.parameters.forEach { write(it) }
-            xml.endElt()
-        }
-        sub.children.forEach { writeNode(it) }
-        xml.endElt()
-    }
-
-    private fun write(parameter: PtSubroutineParameter, registerOrStatusflag: RegisterOrStatusflag? = null) {
-        xml.elt("param")
-        xml.attr("name", parameter.name)
-        xml.attr("type", parameter.type.name)
-        if(registerOrStatusflag?.statusflag!=null) {
-            xml.attr("statusflag", registerOrStatusflag.statusflag!!.toString())
-        }
-        if(registerOrStatusflag?.registerOrPair!=null){
-            xml.attr("registers", registerOrStatusflag.registerOrPair!!.name)
-        }
-        xml.endElt()
-    }
-
-    private fun write(asmSub: PtAsmSub) {
-        if(asmSub.address!=null) {
-            xml.elt("romsub")
-            xml.attr("name", asmSub.scopedName.joinToString("."))
-            xml.attr("address", asmSub.address!!.toString())
-            if(asmSub.inline)
-                xml.attr("inline", "true")
-            xml.pos(asmSub.position)
-            xml.startChildren()
-            paramsEtcetera(asmSub)
-            xml.endElt()
-        }
-        else {
-            xml.elt("asmsub")
-            xml.attr("name", asmSub.scopedName.joinToString("."))
-            if(asmSub.inline)
-                xml.attr("inline", "true")
-            xml.pos(asmSub.position)
-            xml.startChildren()
-            paramsEtcetera(asmSub)
-            xml.elt("code")
-            xml.startChildren()
-            asmSub.children.forEach { writeNode(it) }
-            xml.endElt()
-            xml.endElt()
-        }
-    }
-
-    private fun paramsEtcetera(asmSub: PtAsmSub) {
-        if(asmSub.parameters.isNotEmpty()) {
-            xml.elt("parameters")
-            xml.startChildren()
-            asmSub.parameters.forEach { (param, reg) -> write(param, reg) }
-            xml.endElt()
-        }
-        if(asmSub.clobbers.isNotEmpty()) {
-            xml.elt("clobbers")
-            xml.attr("registers", asmSub.clobbers.joinToString(",") { it.name })
-            xml.endElt()
-        }
-        if(asmSub.retvalRegisters.isNotEmpty()) {
-            xml.elt("returns")
-            xml.startChildren()
-            asmSub.retvalRegisters.forEach {
-                xml.elt("register")
-                if(it.statusflag!=null)
-                    xml.attr("statusflag", it.statusflag!!.toString())
-                if(it.registerOrPair!=null)
-                    xml.attr("registers", it.registerOrPair!!.toString())
-                xml.endElt()
-            }
-            xml.endElt()
-        }
-    }
-
-    private fun write(constant: PtConstant) {
-        xml.writeTextNode("const",
-            listOf(
-                Pair("name", constant.scopedName.joinToString(".")),
-                Pair("type", constant.type.name)
-            ),
-            intOrDouble(constant.type, constant.value).toString(), false)
-    }
-
-    private fun write(variable: PtVariable) {
-        // the variable declaration nodes are still present in the Ast,
-        // but the Symboltable should be used look up their details.
-        xml.elt("vardecl")
-        xml.attr("name", variable.scopedName.joinToString("."))
-        xml.attr("type", variable.type.name)
-        if(variable.arraySize!=null)
-            xml.attr("arraysize", variable.arraySize.toString())
-        if(variable.value!=null) {
-            // static initialization value
-            xml.startChildren()
-            writeNode(variable.value!!)
-        }
-        xml.endElt()
-    }
-
-
-
-    private fun strTargetName(ident: PtIdentifier): String = ident.targetName.joinToString(".")
-
-    private fun strTargetName(call: PtFunctionCall): String = call.functionName.joinToString(".")
-
-    private fun intOrDouble(type: DataType, value: Double): Number =
-        if(type in IntegerDatatypes) value.toInt() else value
-}

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

@@ -0,0 +1,30 @@
+package prog8.codegen.experimental
+
+import prog8.code.SymbolTable
+import prog8.code.ast.PtProgram
+import prog8.code.core.CompilationOptions
+import prog8.code.core.IAssemblyGenerator
+import prog8.code.core.IAssemblyProgram
+import prog8.code.core.IErrorReporter
+import prog8.codegen.intermediate.IRCodeGen
+import prog8.intermediate.IRFileWriter
+
+class CodeGen(private val program: PtProgram,
+              private val symbolTable: SymbolTable,
+              private val options: CompilationOptions,
+              private val errors: IErrorReporter
+): IAssemblyGenerator {
+    override fun compileToAssembly(): IAssemblyProgram? {
+
+        // you could write a code generator directly on the PtProgram AST,
+        // but you can also use the Intermediate Representation to build a codegen on:
+        val irCodeGen = IRCodeGen(program, symbolTable, options, errors)
+        val irProgram = irCodeGen.generate()
+
+        // this stub only writes the IR program to disk but doesn't generate anything else.
+        IRFileWriter(irProgram).writeFile()
+
+        println("** experimental codegen stub: no assembly generated **")
+        return null
+    }
+}

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

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

codeGenIntermediate/build.gradle

@@ -0,0 +1,63 @@
+
+plugins {
+    id 'java'
+    id 'application'
+    id "org.jetbrains.kotlin.jvm"
+}
+
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(javaVersion)
+    }
+}
+
+compileKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+compileTestKotlin {
+    kotlinOptions {
+        jvmTarget = javaVersion
+    }
+}
+
+dependencies {
+    implementation project(':codeCore')
+    implementation 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"
+
+    testImplementation 'io.kotest:kotest-runner-junit5-jvm:5.3.2'
+}
+
+sourceSets {
+    main {
+        java {
+            srcDirs = ["${project.projectDir}/src"]
+        }
+        resources {
+            srcDirs = ["${project.projectDir}/res"]
+        }
+    }
+    test {
+        java {
+            srcDir "${project.projectDir}/test"
+        }
+    }
+}
+
+test {
+    // Enable JUnit 5 (Gradle 4.6+).
+    useJUnitPlatform()
+
+    // Always run tests, even when nothing changed.
+    dependsOn 'cleanTest'
+
+    // Show test results.
+    testLogging {
+        events "skipped", "failed"
+    }
+}

codeGenIntermediate/codeGenIntermediate.iml

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

codeGenIntermediate/src/prog8/codegen/intermediate/AssignmentGen.kt

@@ -0,0 +1,294 @@
+package prog8.codegen.intermediate
+
+import prog8.code.ast.*
+import prog8.code.core.AssemblyError
+import prog8.code.core.DataType
+import prog8.code.core.Position
+import prog8.code.core.SignedDatatypes
+import prog8.intermediate.IRCodeChunk
+import prog8.intermediate.IRCodeInstruction
+import prog8.intermediate.Opcode
+import prog8.intermediate.VmDataType
+
+internal class AssignmentGen(private val codeGen: IRCodeGen, private val expressionEval: ExpressionGen) {
+
+    internal fun translate(assignment: PtAssignment): IRCodeChunk {
+        if(assignment.target.children.single() is PtMachineRegister)
+            throw AssemblyError("assigning to a register should be done by just evaluating the expression into resultregister")
+
+        return if (assignment.isInplaceAssign)
+            translateInplaceAssign(assignment)
+        else
+            translateRegularAssign(assignment)
+    }
+
+    private fun translateInplaceAssign(assignment: PtAssignment): IRCodeChunk {
+        val ident = assignment.target.identifier
+        val memory = assignment.target.memory
+        val array = assignment.target.array
+
+        return if(ident!=null) {
+            assignSelfInMemory(ident.targetName.joinToString("."), assignment.value, assignment)
+        } else if(memory != null) {
+            if(memory.address is PtNumber)
+                assignSelfInMemoryKnownAddress((memory.address as PtNumber).number.toInt(), assignment.value, assignment)
+            else
+                fallbackAssign(assignment)
+        } else if(array!=null) {
+            // NOTE: naive fallback assignment here will sometimes generate code that loads the index value multiple times
+            // in a register. It's way too much work to optimize that here - instead, we trust that the generated IL assembly
+            // will be optimized later and have the double assignments removed.
+            fallbackAssign(assignment)
+        } else {
+            fallbackAssign(assignment)
+        }
+    }
+
+    private fun assignSelfInMemoryKnownAddress(
+        address: Int,
+        value: PtExpression,
+        origAssign: PtAssignment
+    ): IRCodeChunk {
+        val vmDt = codeGen.vmType(value.type)
+        val code = IRCodeChunk(origAssign.position)
+        when(value) {
+            is PtIdentifier -> return code // do nothing, x=x null assignment.
+            is PtMachineRegister -> return code // do nothing, reg=reg null assignment
+            is PtPrefix -> return inplacePrefix(value.operator, vmDt, address, null, value.position)
+            is PtBinaryExpression -> return inplaceBinexpr(value.operator, value.right, vmDt, value.type in SignedDatatypes, address, null, origAssign)
+            is PtMemoryByte -> {
+                return if (!codeGen.options.compTarget.machine.isIOAddress(address.toUInt()))
+                    code // do nothing, mem=mem null assignment.
+                else {
+                    // read and write a (i/o) memory location to itself.
+                    val tempReg = codeGen.vmRegisters.nextFree()
+                    code += IRCodeInstruction(Opcode.LOADM, vmDt, reg1 = tempReg, value = address)
+                    code += IRCodeInstruction(Opcode.STOREM, vmDt, reg1 = tempReg, value = address)
+                    code
+                }
+            }
+            else -> return fallbackAssign(origAssign)
+        }
+    }
+
+    private fun assignSelfInMemory(
+        symbol: String,
+        value: PtExpression,
+        origAssign: PtAssignment
+    ): IRCodeChunk {
+        val vmDt = codeGen.vmType(value.type)
+        val code = IRCodeChunk(origAssign.position)
+        when(value) {
+            is PtIdentifier -> return code // do nothing, x=x null assignment.
+            is PtMachineRegister -> return code // do nothing, reg=reg null assignment
+            is PtPrefix -> return inplacePrefix(value.operator, vmDt, null, symbol, value.position)
+            is PtBinaryExpression -> return inplaceBinexpr(value.operator, value.right, vmDt, value.type in SignedDatatypes, null, symbol, origAssign)
+            is PtMemoryByte -> {
+                val tempReg = codeGen.vmRegisters.nextFree()
+                code += IRCodeInstruction(Opcode.LOADM, vmDt, reg1 = tempReg, labelSymbol = symbol)
+                code += IRCodeInstruction(Opcode.STOREM, vmDt, reg1 = tempReg, labelSymbol = symbol)
+                return code
+            }
+            else -> return fallbackAssign(origAssign)
+        }
+    }
+
+    private fun fallbackAssign(origAssign: PtAssignment): IRCodeChunk {
+        if (codeGen.options.slowCodegenWarnings)
+            codeGen.errors.warn("indirect code for in-place assignment", origAssign.position)
+        return translateRegularAssign(origAssign)
+    }
+
+    private fun inplaceBinexpr(
+        operator: String,
+        operand: PtExpression,
+        vmDt: VmDataType,
+        signed: Boolean,
+        knownAddress: Int?,
+        symbol: String?,
+        origAssign: PtAssignment
+    ): IRCodeChunk {
+        if(knownAddress!=null) {
+            when (operator) {
+                "+" -> return expressionEval.operatorPlusInplace(knownAddress, null, vmDt, operand)
+                "-" -> return expressionEval.operatorMinusInplace(knownAddress, null, vmDt, operand)
+                "*" -> return expressionEval.operatorMultiplyInplace(knownAddress, null, vmDt, operand)
+                "/" -> return expressionEval.operatorDivideInplace(knownAddress, null, vmDt, signed, operand)
+                "|" -> return expressionEval.operatorOrInplace(knownAddress, null, vmDt, operand)
+                "&" -> return expressionEval.operatorAndInplace(knownAddress, null, vmDt, operand)
+                "^" -> return expressionEval.operatorXorInplace(knownAddress, null, vmDt, operand)
+                "<<" -> return expressionEval.operatorShiftLeftInplace(knownAddress, null, vmDt, operand)
+                ">>" -> return expressionEval.operatorShiftRightInplace(knownAddress, null, vmDt, signed, operand)
+                else -> {}
+            }
+        } else {
+            symbol!!
+            when (operator) {
+                "+" -> return expressionEval.operatorPlusInplace(null, symbol, vmDt, operand)
+                "-" -> return expressionEval.operatorMinusInplace(null, symbol, vmDt, operand)
+                "*" -> return expressionEval.operatorMultiplyInplace(null, symbol, vmDt, operand)
+                "/" -> return expressionEval.operatorDivideInplace(null, symbol, vmDt, signed, operand)
+                "|" -> return expressionEval.operatorOrInplace(null, symbol, vmDt, operand)
+                "&" -> return expressionEval.operatorAndInplace(null, symbol, vmDt, operand)
+                "^" -> return expressionEval.operatorXorInplace(null, symbol, vmDt, operand)
+                "<<" -> return expressionEval.operatorShiftLeftInplace(null, symbol, vmDt, operand)
+                ">>" -> return expressionEval.operatorShiftRightInplace(null, symbol, vmDt, signed, operand)
+                else -> {}
+            }
+        }
+        return fallbackAssign(origAssign)
+    }
+
+    private fun inplacePrefix(operator: String, vmDt: VmDataType, knownAddress: Int?, addressSymbol: String?, position: Position): IRCodeChunk {
+        val code= IRCodeChunk(position)
+        when(operator) {
+            "+" -> { }
+            "-" -> {
+                code += if(knownAddress!=null)
+                    IRCodeInstruction(Opcode.NEGM, vmDt, value = knownAddress)
+                else
+                    IRCodeInstruction(Opcode.NEGM, vmDt, labelSymbol = addressSymbol)
+            }
+            "~" -> {
+                val regMask = codeGen.vmRegisters.nextFree()
+                val mask = if(vmDt==VmDataType.BYTE) 0x00ff else 0xffff
+                code += IRCodeInstruction(Opcode.LOAD, vmDt, reg1=regMask, value = mask)
+                code += if(knownAddress!=null)
+                    IRCodeInstruction(Opcode.XORM, vmDt, reg1=regMask, value = knownAddress)
+                else
+                    IRCodeInstruction(Opcode.XORM, vmDt, reg1=regMask, labelSymbol = addressSymbol)
+            }
+            else -> throw AssemblyError("weird prefix operator")
+        }
+        return code
+    }
+
+    private fun translateRegularAssign(assignment: PtAssignment): IRCodeChunk {
+        // note: assigning array and string values is done via an explicit memcopy/stringcopy function call.
+        val ident = assignment.target.identifier
+        val memory = assignment.target.memory
+        val array = assignment.target.array
+        val vmDt = codeGen.vmType(assignment.value.type)
+
+        val code = IRCodeChunk(assignment.position)
+        var resultRegister = -1
+        var resultFpRegister = -1
+        val zero = codeGen.isZero(assignment.value)
+        if(!zero) {
+            // calculate the assignment value
+            if (vmDt == VmDataType.FLOAT) {
+                resultFpRegister = codeGen.vmRegisters.nextFreeFloat()
+                code += expressionEval.translateExpression(assignment.value, -1, resultFpRegister)
+            } else {
+                resultRegister = if (assignment.value is PtMachineRegister) {
+                    (assignment.value as PtMachineRegister).register
+                } else {
+                    val reg = codeGen.vmRegisters.nextFree()
+                    code += expressionEval.translateExpression(assignment.value, reg, -1)
+                    reg
+                }
+            }
+        }
+        if(ident!=null) {
+            val symbol = ident.targetName.joinToString(".")
+            code += if(zero) {
+                IRCodeInstruction(Opcode.STOREZM, vmDt, labelSymbol = symbol)
+            } else {
+                if (vmDt == VmDataType.FLOAT)
+                    IRCodeInstruction(Opcode.STOREM, vmDt, fpReg1 = resultFpRegister, labelSymbol = symbol)
+                else
+                    IRCodeInstruction(Opcode.STOREM, vmDt, reg1 = resultRegister, labelSymbol = symbol)
+            }
+        }
+        else if(array!=null) {
+            val variable = array.variable.targetName.joinToString(".")
+            val itemsize = codeGen.program.memsizer.memorySize(array.type)
+
+            if(array.variable.type==DataType.UWORD) {
+                // indexing a pointer var instead of a real array or string
+                if(itemsize!=1)
+                    throw AssemblyError("non-array var indexing requires bytes dt")
+                if(array.index.type!=DataType.UBYTE)
+                    throw AssemblyError("non-array var indexing requires bytes index")
+                val idxReg = codeGen.vmRegisters.nextFree()
+                code += expressionEval.translateExpression(array.index, idxReg, -1)
+                if(zero) {
+                    // there's no STOREZIX instruction
+                    resultRegister = codeGen.vmRegisters.nextFree()
+                    code += IRCodeInstruction(Opcode.LOAD, vmDt, reg1=resultRegister, value=0)
+                }
+                code += IRCodeInstruction(Opcode.STOREIX, vmDt, reg1=resultRegister, reg2=idxReg, labelSymbol = variable)
+                return code
+            }
+
+            val fixedIndex = constIntValue(array.index)
+            if(zero) {
+                if(fixedIndex!=null) {
+                    val offset = fixedIndex*itemsize
+                    code += IRCodeInstruction(Opcode.STOREZM, vmDt, labelSymbol = "$variable+$offset")
+                } else {
+                    val indexReg = codeGen.vmRegisters.nextFree()
+                    code += loadIndexReg(array, itemsize, indexReg, array.position)
+                    code += IRCodeInstruction(Opcode.STOREZX, vmDt, reg1=indexReg, labelSymbol = variable)
+                }
+            } else {
+                if(vmDt== VmDataType.FLOAT) {
+                    if(fixedIndex!=null) {
+                        val offset = fixedIndex*itemsize
+                        code += IRCodeInstruction(Opcode.STOREM, vmDt, fpReg1 = resultFpRegister, labelSymbol = "$variable+$offset")
+                    } else {
+                        val indexReg = codeGen.vmRegisters.nextFree()
+                        code += loadIndexReg(array, itemsize, indexReg, array.position)
+                        code += IRCodeInstruction(Opcode.STOREX, vmDt, reg1 = resultRegister, reg2=indexReg, labelSymbol = variable)
+                    }
+                } else {
+                    if(fixedIndex!=null) {
+                        val offset = fixedIndex*itemsize
+                        code += IRCodeInstruction(Opcode.STOREM, vmDt, reg1 = resultRegister, labelSymbol = "$variable+$offset")
+                    } else {
+                        val indexReg = codeGen.vmRegisters.nextFree()
+                        code += loadIndexReg(array, itemsize, indexReg, array.position)
+                        code += IRCodeInstruction(Opcode.STOREX, vmDt, reg1 = resultRegister, reg2=indexReg, labelSymbol = variable)
+                    }
+                }
+            }
+        }
+        else if(memory!=null) {
+            require(vmDt== VmDataType.BYTE)
+            if(zero) {
+                if(memory.address is PtNumber) {
+                    code += IRCodeInstruction(Opcode.STOREZM, vmDt, value=(memory.address as PtNumber).number.toInt())
+                } else {
+                    val addressReg = codeGen.vmRegisters.nextFree()
+                    code += expressionEval.translateExpression(memory.address, addressReg, -1)
+                    code += IRCodeInstruction(Opcode.STOREZI, vmDt, reg1=addressReg)
+                }
+            } else {
+                if(memory.address is PtNumber) {
+                    code += IRCodeInstruction(Opcode.STOREM, vmDt, reg1=resultRegister, value=(memory.address as PtNumber).number.toInt())
+                } else {
+                    val addressReg = codeGen.vmRegisters.nextFree()
+                    code += expressionEval.translateExpression(memory.address, addressReg, -1)
+                    code += IRCodeInstruction(Opcode.STOREI, vmDt, reg1=resultRegister, reg2=addressReg)
+                }
+            }
+        }
+        else
+            throw AssemblyError("weird assigntarget")
+        return code
+    }
+
+    private fun loadIndexReg(array: PtArrayIndexer, itemsize: Int, indexReg: Int, position: Position): IRCodeChunk {
+        val code = IRCodeChunk(position)
+        if(itemsize==1) {
+            code += expressionEval.translateExpression(array.index, indexReg, -1)
+        }
+        else {
+            val mult = PtBinaryExpression("*", DataType.UBYTE, array.position)
+            mult.children += array.index
+            mult.children += PtNumber(DataType.UBYTE, itemsize.toDouble(), array.position)
+            code += expressionEval.translateExpression(mult, indexReg, -1)
+        }
+        return code
+    }
+}

codeGenIntermediate/src/prog8/codegen/intermediate/BuiltinFuncGen.kt

@@ -1,16 +1,16 @@
-package prog8.codegen.virtual
+package prog8.codegen.intermediate
 
 import prog8.code.StStaticVariable
 import prog8.code.ast.*
 import prog8.code.core.AssemblyError
 import prog8.code.core.DataType
-import prog8.vm.Opcode
-import prog8.vm.Syscall
-import prog8.vm.VmDataType
+import prog8.code.core.Position
+import prog8.intermediate.*
 
-internal class BuiltinFuncGen(private val codeGen: CodeGen, private val exprGen: ExpressionGen) {
 
-    fun translate(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk {
+internal class BuiltinFuncGen(private val codeGen: IRCodeGen, private val exprGen: ExpressionGen) {
+
+    fun translate(call: PtBuiltinFunctionCall, resultRegister: Int): IRCodeChunk {
         return when(call.name) {
             "any" -> funcAny(call, resultRegister)
             "all" -> funcAll(call, resultRegister)
@@ -25,9 +25,9 @@ internal class BuiltinFuncGen(private val codeGen: CodeGen, private val exprGen:
             "rsave",
             "rsavex",
             "rrestore",
-            "rrestorex" -> VmCodeChunk() // vm doesn't have registers to save/restore
-            "rnd" -> funcRnd(resultRegister)
-            "rndw" -> funcRndw(resultRegister)
+            "rrestorex" -> IRCodeChunk(call.position) // vm doesn't have registers to save/restore
+            "rnd" -> funcRnd(resultRegister, call.position)
+            "rndw" -> funcRndw(resultRegister, call.position)
             "callfar" -> throw AssemblyError("callfar() is for cx16 target only")
             "callrom" -> throw AssemblyError("callrom() is for cx16 target only")
             "msb" -> funcMsb(call, resultRegister)
@@ -37,98 +37,97 @@ internal class BuiltinFuncGen(private val codeGen: CodeGen, private val exprGen:
             "peekw" -> funcPeekW(call, resultRegister)
             "poke" -> funcPoke(call)
             "pokew" -> funcPokeW(call)
-            "pokemon" -> VmCodeChunk()
+            "pokemon" -> IRCodeChunk(call.position)
             "mkword" -> funcMkword(call, resultRegister)
             "sort" -> funcSort(call)
             "reverse" -> funcReverse(call)
-            "swap" -> funcSwap(call)
-            "rol" -> funcRolRor2(Opcode.ROXL, call, resultRegister)
-            "ror" -> funcRolRor2(Opcode.ROXR, call, resultRegister)
-            "rol2" -> funcRolRor2(Opcode.ROL, call, resultRegister)
-            "ror2" -> funcRolRor2(Opcode.ROR, call, resultRegister)
-            else -> TODO("builtinfunc ${call.name}")
+            "rol" -> funcRolRor(Opcode.ROXL, call, resultRegister)
+            "ror" -> funcRolRor(Opcode.ROXR, call, resultRegister)
+            "rol2" -> funcRolRor(Opcode.ROL, call, resultRegister)
+            "ror2" -> funcRolRor(Opcode.ROR, call, resultRegister)
+            else -> throw AssemblyError("missing builtinfunc for ${call.name}")
         }
     }
 
-    private fun funcCmp(call: PtBuiltinFunctionCall): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun funcCmp(call: PtBuiltinFunctionCall): IRCodeChunk {
+        val code = IRCodeChunk(call.position)
         val leftRegister = codeGen.vmRegisters.nextFree()
         val rightRegister = codeGen.vmRegisters.nextFree()
         code += exprGen.translateExpression(call.args[0], leftRegister, -1)
         code += exprGen.translateExpression(call.args[1], rightRegister, -1)
-        code += VmCodeInstruction(Opcode.CMP, codeGen.vmType(call.args[0].type), reg1=leftRegister, reg2=rightRegister)
+        code += IRCodeInstruction(Opcode.CMP, codeGen.vmType(call.args[0].type), reg1=leftRegister, reg2=rightRegister)
         return code
     }
 
-    private fun funcAny(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk {
+    private fun funcAny(call: PtBuiltinFunctionCall, resultRegister: Int): IRCodeChunk {
         val arrayName = call.args[0] as PtIdentifier
         val array = codeGen.symbolTable.flat.getValue(arrayName.targetName) as StStaticVariable
-        val code = VmCodeChunk()
+        val code = IRCodeChunk(call.position)
         val syscall =
             when (array.dt) {
                 DataType.ARRAY_UB,
-                DataType.ARRAY_B -> Syscall.ANY_BYTE
+                DataType.ARRAY_B -> IMSyscall.ANY_BYTE
                 DataType.ARRAY_UW,
-                DataType.ARRAY_W -> Syscall.ANY_WORD
-                DataType.ARRAY_F -> Syscall.ANY_FLOAT
+                DataType.ARRAY_W -> IMSyscall.ANY_WORD
+                DataType.ARRAY_F -> IMSyscall.ANY_FLOAT
                 else -> throw IllegalArgumentException("weird type")
             }
         code += exprGen.translateExpression(call.args[0], 0, -1)
-        code += VmCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1 = 1, value = array.length)
-        code += VmCodeInstruction(Opcode.SYSCALL, value = syscall.ordinal)
+        code += IRCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1 = 1, value = array.length)
+        code += IRCodeInstruction(Opcode.SYSCALL, value = syscall.ordinal)
         if (resultRegister != 0)
-            code += VmCodeInstruction(Opcode.LOADR, VmDataType.BYTE, reg1 = resultRegister, reg2 = 0)
+            code += IRCodeInstruction(Opcode.LOADR, VmDataType.BYTE, reg1 = resultRegister, reg2 = 0)
         return code
     }
 
-    private fun funcAll(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk {
+    private fun funcAll(call: PtBuiltinFunctionCall, resultRegister: Int): IRCodeChunk {
         val arrayName = call.args[0] as PtIdentifier
         val array = codeGen.symbolTable.flat.getValue(arrayName.targetName) as StStaticVariable
         val syscall =
             when(array.dt) {
                 DataType.ARRAY_UB,
-                DataType.ARRAY_B -> Syscall.ALL_BYTE
+                DataType.ARRAY_B -> IMSyscall.ALL_BYTE
                 DataType.ARRAY_UW,
-                DataType.ARRAY_W -> Syscall.ALL_WORD
-                DataType.ARRAY_F -> Syscall.ALL_FLOAT
+                DataType.ARRAY_W -> IMSyscall.ALL_WORD
+                DataType.ARRAY_F -> IMSyscall.ALL_FLOAT
                 else -> throw IllegalArgumentException("weird type")
             }
-        val code = VmCodeChunk()
+        val code = IRCodeChunk(call.position)
         code += exprGen.translateExpression(call.args[0], 0, -1)
-        code += VmCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=1, value=array.length)
-        code += VmCodeInstruction(Opcode.SYSCALL, value=syscall.ordinal)
+        code += IRCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=1, value=array.length)
+        code += IRCodeInstruction(Opcode.SYSCALL, value=syscall.ordinal)
         if(resultRegister!=0)
-            code += VmCodeInstruction(Opcode.LOADR, VmDataType.BYTE, reg1=resultRegister, reg2=0)
+            code += IRCodeInstruction(Opcode.LOADR, VmDataType.BYTE, reg1=resultRegister, reg2=0)
         return code
     }
 
-    private fun funcAbs(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun funcAbs(call: PtBuiltinFunctionCall, resultRegister: Int): IRCodeChunk {
+        val code = IRCodeChunk(call.position)
         val sourceDt = call.args.single().type
         if(sourceDt!=DataType.UWORD) {
             code += exprGen.translateExpression(call.args[0], resultRegister, -1)
             when (sourceDt) {
                 DataType.UBYTE -> {
-                    code += VmCodeInstruction(Opcode.EXT, VmDataType.BYTE, reg1=resultRegister)
+                    code += IRCodeInstruction(Opcode.EXT, VmDataType.BYTE, reg1=resultRegister)
                 }
                 DataType.BYTE -> {
-                    val andReg = codeGen.vmRegisters.nextFree()
                     val notNegativeLabel = codeGen.createLabelName()
-                    code += VmCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=andReg, value=0x80)
-                    code += VmCodeInstruction(Opcode.AND, VmDataType.BYTE, reg1=andReg, reg2=resultRegister)
-                    code += VmCodeInstruction(Opcode.BZ, VmDataType.BYTE, reg1=andReg, labelSymbol = notNegativeLabel)
-                    code += VmCodeInstruction(Opcode.NEG, VmDataType.BYTE, reg1=resultRegister)
-                    code += VmCodeInstruction(Opcode.EXT, VmDataType.BYTE, reg1=resultRegister)
-                    code += VmCodeLabel(notNegativeLabel)
+                    val compareReg = codeGen.vmRegisters.nextFree()
+                    code += IRCodeInstruction(Opcode.LOADR, VmDataType.BYTE, reg1=compareReg, reg2=resultRegister)
+                    code += IRCodeInstruction(Opcode.AND, VmDataType.BYTE, reg1=compareReg, value=0x80)
+                    code += IRCodeInstruction(Opcode.BZ, VmDataType.BYTE, reg1=compareReg, labelSymbol = notNegativeLabel)
+                    code += IRCodeInstruction(Opcode.NEG, VmDataType.BYTE, reg1=resultRegister)
+                    code += IRCodeInstruction(Opcode.EXT, VmDataType.BYTE, reg1=resultRegister)
+                    code += IRCodeLabel(notNegativeLabel)
                 }
                 DataType.WORD -> {
-                    val andReg = codeGen.vmRegisters.nextFree()
                     val notNegativeLabel = codeGen.createLabelName()
-                    code += VmCodeInstruction(Opcode.LOAD, VmDataType.WORD, reg1=andReg, value=0x8000)
-                    code += VmCodeInstruction(Opcode.AND, VmDataType.WORD, reg1=andReg, reg2=resultRegister)
-                    code += VmCodeInstruction(Opcode.BZ, VmDataType.WORD, reg1=andReg, labelSymbol = notNegativeLabel)
-                    code += VmCodeInstruction(Opcode.NEG, VmDataType.WORD, reg1=resultRegister)
-                    code += VmCodeLabel(notNegativeLabel)
+                    val compareReg = codeGen.vmRegisters.nextFree()
+                    code += IRCodeInstruction(Opcode.LOADR, VmDataType.WORD, reg1=compareReg, reg2=resultRegister)
+                    code += IRCodeInstruction(Opcode.AND, VmDataType.WORD, reg1=compareReg, value=0x8000)
+                    code += IRCodeInstruction(Opcode.BZ, VmDataType.WORD, reg1=compareReg, labelSymbol = notNegativeLabel)
+                    code += IRCodeInstruction(Opcode.NEG, VmDataType.WORD, reg1=resultRegister)
+                    code += IRCodeLabel(notNegativeLabel)
                 }
                 else -> throw AssemblyError("weird type")
             }
@@ -136,249 +135,228 @@ internal class BuiltinFuncGen(private val codeGen: CodeGen, private val exprGen:
         return code
     }
 
-    private fun funcSgn(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun funcSgn(call: PtBuiltinFunctionCall, resultRegister: Int): IRCodeChunk {
+        val code = IRCodeChunk(call.position)
         val reg = codeGen.vmRegisters.nextFree()
         code += exprGen.translateExpression(call.args.single(), reg, -1)
-        code += VmCodeInstruction(Opcode.SGN, codeGen.vmType(call.type), reg1=resultRegister, reg2=reg)
+        code += IRCodeInstruction(Opcode.SGN, codeGen.vmType(call.type), reg1=resultRegister, reg2=reg)
         return code
     }
 
-    private fun funcSqrt16(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun funcSqrt16(call: PtBuiltinFunctionCall, resultRegister: Int): IRCodeChunk {
+        val code = IRCodeChunk(call.position)
         val reg = codeGen.vmRegisters.nextFree()
         code += exprGen.translateExpression(call.args.single(), reg, -1)
-        code += VmCodeInstruction(Opcode.SQRT, VmDataType.WORD, reg1=resultRegister, reg2=reg)
+        code += IRCodeInstruction(Opcode.SQRT, VmDataType.WORD, reg1=resultRegister, reg2=reg)
         return code
     }
 
-    private fun funcPop(call: PtBuiltinFunctionCall): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun funcPop(call: PtBuiltinFunctionCall): IRCodeChunk {
+        val code = IRCodeChunk(call.position)
         val reg = codeGen.vmRegisters.nextFree()
-        code += VmCodeInstruction(Opcode.POP, VmDataType.BYTE, reg1=reg)
+        code += IRCodeInstruction(Opcode.POP, VmDataType.BYTE, reg1=reg)
         code += assignRegisterTo(call.args.single(), reg)
         return code
     }
 
-    private fun funcPopw(call: PtBuiltinFunctionCall): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun funcPopw(call: PtBuiltinFunctionCall): IRCodeChunk {
+        val code = IRCodeChunk(call.position)
         val reg = codeGen.vmRegisters.nextFree()
-        code += VmCodeInstruction(Opcode.POP, VmDataType.WORD, reg1=reg)
+        code += IRCodeInstruction(Opcode.POP, VmDataType.WORD, reg1=reg)
         code += assignRegisterTo(call.args.single(), reg)
         return code
     }
 
-    private fun funcPush(call: PtBuiltinFunctionCall): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun funcPush(call: PtBuiltinFunctionCall): IRCodeChunk {
+        val code = IRCodeChunk(call.position)
         val reg = codeGen.vmRegisters.nextFree()
         code += exprGen.translateExpression(call.args.single(), reg, -1)
-        code += VmCodeInstruction(Opcode.PUSH, VmDataType.BYTE, reg1=reg)
+        code += IRCodeInstruction(Opcode.PUSH, VmDataType.BYTE, reg1=reg)
         return code
     }
 
-    private fun funcPushw(call: PtBuiltinFunctionCall): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun funcPushw(call: PtBuiltinFunctionCall): IRCodeChunk {
+        val code = IRCodeChunk(call.position)
         val reg = codeGen.vmRegisters.nextFree()
         code += exprGen.translateExpression(call.args.single(), reg, -1)
-        code += VmCodeInstruction(Opcode.PUSH, VmDataType.WORD, reg1=reg)
+        code += IRCodeInstruction(Opcode.PUSH, VmDataType.WORD, reg1=reg)
         return code
     }
 
-    private fun funcSwap(call: PtBuiltinFunctionCall): VmCodeChunk {
-        val left = call.args[0]
-        val right = call.args[1]
-        val leftReg = codeGen.vmRegisters.nextFree()
-        val rightReg = codeGen.vmRegisters.nextFree()
-        val code = VmCodeChunk()
-        code += exprGen.translateExpression(left, leftReg, -1)
-        code += exprGen.translateExpression(right, rightReg, -1)
-        code += assignRegisterTo(left, rightReg)
-        code += assignRegisterTo(right, leftReg)
-        return code
-    }
-
-    private fun funcReverse(call: PtBuiltinFunctionCall): VmCodeChunk {
+    private fun funcReverse(call: PtBuiltinFunctionCall): IRCodeChunk {
         val arrayName = call.args[0] as PtIdentifier
         val array = codeGen.symbolTable.flat.getValue(arrayName.targetName) as StStaticVariable
-        val sortSyscall =
+        val syscall =
             when(array.dt) {
-                DataType.ARRAY_UB, DataType.ARRAY_B, DataType.STR -> Syscall.REVERSE_BYTES
-                DataType.ARRAY_UW, DataType.ARRAY_W -> Syscall.REVERSE_WORDS
-                DataType.ARRAY_F -> Syscall.REVERSE_FLOATS
+                DataType.ARRAY_UB, DataType.ARRAY_B, DataType.STR -> IMSyscall.REVERSE_BYTES
+                DataType.ARRAY_UW, DataType.ARRAY_W -> IMSyscall.REVERSE_WORDS
+                DataType.ARRAY_F -> IMSyscall.REVERSE_FLOATS
                 else -> throw IllegalArgumentException("weird type to reverse")
             }
-        val code = VmCodeChunk()
+        val code = IRCodeChunk(call.position)
         code += exprGen.translateExpression(call.args[0], 0, -1)
-        code += VmCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=1, value=array.length)
-        code += VmCodeInstruction(Opcode.SYSCALL, value=sortSyscall.ordinal)
+        code += IRCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=1, value=array.length)
+        code += IRCodeInstruction(Opcode.SYSCALL, value=syscall.ordinal)
         return code
     }
 
-    private fun funcSort(call: PtBuiltinFunctionCall): VmCodeChunk {
+    private fun funcSort(call: PtBuiltinFunctionCall): IRCodeChunk {
         val arrayName = call.args[0] as PtIdentifier
         val array = codeGen.symbolTable.flat.getValue(arrayName.targetName) as StStaticVariable
-        val sortSyscall =
+        val syscall =
             when(array.dt) {
-                DataType.ARRAY_UB -> Syscall.SORT_UBYTE
-                DataType.ARRAY_B -> Syscall.SORT_BYTE
-                DataType.ARRAY_UW -> Syscall.SORT_UWORD
-                DataType.ARRAY_W -> Syscall.SORT_WORD
-                DataType.STR -> Syscall.SORT_UBYTE
-                DataType.ARRAY_F -> throw java.lang.IllegalArgumentException("sorting a floating point array is not supported")
+                DataType.ARRAY_UB -> IMSyscall.SORT_UBYTE
+                DataType.ARRAY_B -> IMSyscall.SORT_BYTE
+                DataType.ARRAY_UW -> IMSyscall.SORT_UWORD
+                DataType.ARRAY_W -> IMSyscall.SORT_WORD
+                DataType.STR -> IMSyscall.SORT_UBYTE
+                DataType.ARRAY_F -> throw IllegalArgumentException("sorting a floating point array is not supported")
                 else -> throw IllegalArgumentException("weird type to sort")
             }
-        val code = VmCodeChunk()
+        val code = IRCodeChunk(call.position)
         code += exprGen.translateExpression(call.args[0], 0, -1)
-        code += VmCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=1, value=array.length)
-        code += VmCodeInstruction(Opcode.SYSCALL, value=sortSyscall.ordinal)
+        code += IRCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=1, value=array.length)
+        code += IRCodeInstruction(Opcode.SYSCALL, value=syscall.ordinal)
         return code
     }
 
-    private fun funcMkword(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk {
+    private fun funcMkword(call: PtBuiltinFunctionCall, resultRegister: Int): IRCodeChunk {
         val msbReg = codeGen.vmRegisters.nextFree()
-        val code = VmCodeChunk()
+        val code = IRCodeChunk(call.position)
         code += exprGen.translateExpression(call.args[0], msbReg, -1)
         code += exprGen.translateExpression(call.args[1], resultRegister, -1)
-        code += VmCodeInstruction(Opcode.CONCAT, VmDataType.BYTE, reg1=resultRegister, reg2=msbReg)
+        code += IRCodeInstruction(Opcode.CONCAT, VmDataType.BYTE, reg1=resultRegister, reg2=msbReg)
         return code
     }
 
-    private fun funcPokeW(call: PtBuiltinFunctionCall): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun funcPokeW(call: PtBuiltinFunctionCall): IRCodeChunk {
+        val code = IRCodeChunk(call.position)
         if(codeGen.isZero(call.args[1])) {
             if (call.args[0] is PtNumber) {
                 val address = (call.args[0] as PtNumber).number.toInt()
-                code += VmCodeInstruction(Opcode.STOREZM, VmDataType.WORD, value = address)
+                code += IRCodeInstruction(Opcode.STOREZM, VmDataType.WORD, value = address)
             } else {
                 val addressReg = codeGen.vmRegisters.nextFree()
                 code += exprGen.translateExpression(call.args[0], addressReg, -1)
-                code += VmCodeInstruction(Opcode.STOREZI, VmDataType.WORD, reg2 = addressReg)
+                code += IRCodeInstruction(Opcode.STOREZI, VmDataType.WORD, reg2 = addressReg)
             }
         } else {
             val valueReg = codeGen.vmRegisters.nextFree()
             if (call.args[0] is PtNumber) {
                 val address = (call.args[0] as PtNumber).number.toInt()
                 code += exprGen.translateExpression(call.args[1], valueReg, -1)
-                code += VmCodeInstruction(Opcode.STOREM, VmDataType.WORD, reg1 = valueReg, value = address)
+                code += IRCodeInstruction(Opcode.STOREM, VmDataType.WORD, reg1 = valueReg, value = address)
             } else {
                 val addressReg = codeGen.vmRegisters.nextFree()
                 code += exprGen.translateExpression(call.args[0], addressReg, -1)
                 code += exprGen.translateExpression(call.args[1], valueReg, -1)
-                code += VmCodeInstruction(Opcode.STOREI, VmDataType.WORD, reg1 = valueReg, reg2 = addressReg)
+                code += IRCodeInstruction(Opcode.STOREI, VmDataType.WORD, reg1 = valueReg, reg2 = addressReg)
             }
         }
         return code
     }
 
-    private fun funcPoke(call: PtBuiltinFunctionCall): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun funcPoke(call: PtBuiltinFunctionCall): IRCodeChunk {
+        val code = IRCodeChunk(call.position)
         if(codeGen.isZero(call.args[1])) {
             if (call.args[0] is PtNumber) {
                 val address = (call.args[0] as PtNumber).number.toInt()
-                code += VmCodeInstruction(Opcode.STOREZM, VmDataType.BYTE, value = address)
+                code += IRCodeInstruction(Opcode.STOREZM, VmDataType.BYTE, value = address)
             } else {
                 val addressReg = codeGen.vmRegisters.nextFree()
                 code += exprGen.translateExpression(call.args[0], addressReg, -1)
-                code += VmCodeInstruction(Opcode.STOREZI, VmDataType.BYTE, reg2 = addressReg)
+                code += IRCodeInstruction(Opcode.STOREZI, VmDataType.BYTE, reg2 = addressReg)
             }
         } else {
             val valueReg = codeGen.vmRegisters.nextFree()
             if (call.args[0] is PtNumber) {
                 val address = (call.args[0] as PtNumber).number.toInt()
                 code += exprGen.translateExpression(call.args[1], valueReg, -1)
-                code += VmCodeInstruction(Opcode.STOREM, VmDataType.BYTE, reg1 = valueReg, value = address)
+                code += IRCodeInstruction(Opcode.STOREM, VmDataType.BYTE, reg1 = valueReg, value = address)
             } else {
                 val addressReg = codeGen.vmRegisters.nextFree()
                 code += exprGen.translateExpression(call.args[0], addressReg, -1)
                 code += exprGen.translateExpression(call.args[1], valueReg, -1)
-                code += VmCodeInstruction(Opcode.STOREI, VmDataType.BYTE, reg1 = valueReg, reg2 = addressReg)
+                code += IRCodeInstruction(Opcode.STOREI, VmDataType.BYTE, reg1 = valueReg, reg2 = addressReg)
             }
         }
         return code
     }
 
-    private fun funcPeekW(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun funcPeekW(call: PtBuiltinFunctionCall, resultRegister: Int): IRCodeChunk {
+        val code = IRCodeChunk(call.position)
         if(call.args[0] is PtNumber) {
             val address = (call.args[0] as PtNumber).number.toInt()
-            code += VmCodeInstruction(Opcode.LOADM, VmDataType.WORD, reg1 = resultRegister, value = address)
+            code += IRCodeInstruction(Opcode.LOADM, VmDataType.WORD, reg1 = resultRegister, value = address)
         } else {
             val addressReg = codeGen.vmRegisters.nextFree()
             code += exprGen.translateExpression(call.args.single(), addressReg, -1)
-            code += VmCodeInstruction(Opcode.LOADI, VmDataType.WORD, reg1 = resultRegister, reg2 = addressReg)
+            code += IRCodeInstruction(Opcode.LOADI, VmDataType.WORD, reg1 = resultRegister, reg2 = addressReg)
         }
         return code
     }
 
-    private fun funcPeek(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun funcPeek(call: PtBuiltinFunctionCall, resultRegister: Int): IRCodeChunk {
+        val code = IRCodeChunk(call.position)
         if(call.args[0] is PtNumber) {
             val address = (call.args[0] as PtNumber).number.toInt()
-            code += VmCodeInstruction(Opcode.LOADM, VmDataType.BYTE, reg1 = resultRegister, value = address)
+            code += IRCodeInstruction(Opcode.LOADM, VmDataType.BYTE, reg1 = resultRegister, value = address)
         } else {
             val addressReg = codeGen.vmRegisters.nextFree()
             code += exprGen.translateExpression(call.args.single(), addressReg, -1)
-            code += VmCodeInstruction(Opcode.LOADI, VmDataType.BYTE, reg1 = resultRegister, reg2 = addressReg)
+            code += IRCodeInstruction(Opcode.LOADI, VmDataType.BYTE, reg1 = resultRegister, reg2 = addressReg)
         }
         return code
     }
 
-    private fun funcRnd(resultRegister: Int): VmCodeChunk {
-        val code = VmCodeChunk()
-        code += VmCodeInstruction(Opcode.RND, VmDataType.BYTE, reg1=resultRegister)
+    private fun funcRnd(resultRegister: Int, position: Position): IRCodeChunk {
+        val code = IRCodeChunk(position)
+        code += IRCodeInstruction(Opcode.RND, VmDataType.BYTE, reg1=resultRegister)
         return code
     }
 
-    private fun funcRndw(resultRegister: Int): VmCodeChunk {
-        val code = VmCodeChunk()
-        code += VmCodeInstruction(Opcode.RND, VmDataType.WORD, reg1=resultRegister)
+    private fun funcRndw(resultRegister: Int, position: Position): IRCodeChunk {
+        val code = IRCodeChunk(position)
+        code += IRCodeInstruction(Opcode.RND, VmDataType.WORD, reg1=resultRegister)
         return code
     }
 
-    private fun funcMemory(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk {
+    private fun funcMemory(call: PtBuiltinFunctionCall, resultRegister: Int): IRCodeChunk {
         val name = (call.args[0] as PtString).value
         val size = (call.args[1] as PtNumber).number.toUInt()
         val align = (call.args[2] as PtNumber).number.toUInt()
-        val existing = codeGen.allocations.getMemorySlab(name)
-        val address = if(existing==null)
-            codeGen.allocations.allocateMemorySlab(name, size, align)
-        else if(existing.second!=size || existing.third!=align) {
-            codeGen.errors.err("memory slab '$name' already exists with a different size or alignment", call.position)
-            return VmCodeChunk()
-        }
-        else
-            existing.first
-        val code = VmCodeChunk()
-        code += VmCodeInstruction(Opcode.LOAD, VmDataType.WORD, reg1=resultRegister, value=address.toInt())
+        val label = codeGen.addMemorySlab(name, size, align, call.position)
+        val code = IRCodeChunk(call.position)
+        code += IRCodeInstruction(Opcode.LOAD, VmDataType.WORD, reg1=resultRegister, labelSymbol = label)
         return code
     }
 
-    private fun funcLsb(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun funcLsb(call: PtBuiltinFunctionCall, resultRegister: Int): IRCodeChunk {
+        val code = IRCodeChunk(call.position)
         code += exprGen.translateExpression(call.args.single(), resultRegister, -1)
         // note: if a word result is needed, the upper byte is cleared by the typecast that follows. No need to do it here.
         return code
     }
 
-    private fun funcMsb(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun funcMsb(call: PtBuiltinFunctionCall, resultRegister: Int): IRCodeChunk {
+        val code = IRCodeChunk(call.position)
         code += exprGen.translateExpression(call.args.single(), resultRegister, -1)
-        code += VmCodeInstruction(Opcode.MSIG, VmDataType.BYTE, reg1 = resultRegister, reg2=resultRegister)
+        code += IRCodeInstruction(Opcode.MSIG, VmDataType.BYTE, reg1 = resultRegister, reg2=resultRegister)
         // note: if a word result is needed, the upper byte is cleared by the typecast that follows. No need to do it here.
         return code
     }
 
-    private fun funcRolRor2(opcode: Opcode, call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk {
+    private fun funcRolRor(opcode: Opcode, call: PtBuiltinFunctionCall, resultRegister: Int): IRCodeChunk {
         val vmDt = codeGen.vmType(call.args[0].type)
-        val code = VmCodeChunk()
+        val code = IRCodeChunk(call.position)
         code += exprGen.translateExpression(call.args[0], resultRegister, -1)
-        code += VmCodeInstruction(opcode, vmDt, reg1=resultRegister)
+        code += IRCodeInstruction(opcode, vmDt, reg1=resultRegister)
         code += assignRegisterTo(call.args[0], resultRegister)
         return code
     }
 
-    private fun assignRegisterTo(target: PtExpression, register: Int): VmCodeChunk {
-        val code = VmCodeChunk()
+    private fun assignRegisterTo(target: PtExpression, register: Int): IRCodeChunk {
+        val code = IRCodeChunk(target.position)
         val assignment = PtAssignment(target.position)
         val assignTarget = PtAssignTarget(target.position)
         assignTarget.children.add(target)

codeGenIntermediate/src/prog8/codegen/intermediate/IRPeepholeOptimizer.kt

@@ -0,0 +1,180 @@
+package prog8.codegen.intermediate
+
+import prog8.intermediate.*
+
+internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
+    fun optimize() {
+        irprog.blocks.asSequence().flatMap { it.subroutines }.forEach { sub ->
+            sub.chunks.forEach { chunk ->
+                // we don't optimize Inline Asm chunks here.
+                if(chunk is IRCodeChunk) {
+                    do {
+                        val indexedInstructions = chunk.lines.withIndex()
+                            .filter { it.value is IRCodeInstruction }
+                            .map { IndexedValue(it.index, (it.value as IRCodeInstruction).ins) }
+                        val changed = removeNops(chunk, indexedInstructions)
+                                || removeDoubleLoadsAndStores(chunk, indexedInstructions)       // TODO not yet implemented
+                                || removeUselessArithmetic(chunk, indexedInstructions)
+                                || removeWeirdBranches(chunk, indexedInstructions)
+                                || removeDoubleSecClc(chunk, indexedInstructions)
+                                || cleanupPushPop(chunk, indexedInstructions)
+                        // TODO other optimizations:
+                        //  more complex optimizations such as unused registers
+                    } while (changed)
+                }
+            }
+        }
+    }
+
+    private fun cleanupPushPop(chunk: IRCodeChunk, indexedInstructions: List<IndexedValue<Instruction>>): Boolean {
+        //  push followed by pop to same target, or different target->replace with load
+        var changed = false
+        indexedInstructions.reversed().forEach { (idx, ins) ->
+            if(ins.opcode== Opcode.PUSH) {
+                if(idx < chunk.lines.size-1) {
+                    val insAfter = chunk.lines[idx+1] as? IRCodeInstruction
+                    if(insAfter!=null && insAfter.ins.opcode == Opcode.POP) {
+                        if(ins.reg1==insAfter.ins.reg1) {
+                            chunk.lines.removeAt(idx)
+                            chunk.lines.removeAt(idx)
+                        } else {
+                            chunk.lines[idx] = IRCodeInstruction(Opcode.LOADR, ins.type, reg1=insAfter.ins.reg1, reg2=ins.reg1)
+                            chunk.lines.removeAt(idx+1)
+                        }
+                        changed = true
+                    }
+                }
+            }
+        }
+        return changed
+    }
+
+    private fun removeDoubleSecClc(chunk: IRCodeChunk, indexedInstructions: List<IndexedValue<Instruction>>): Boolean {
+        //  double sec, clc
+        //  sec+clc or clc+sec
+        var changed = false
+        indexedInstructions.reversed().forEach { (idx, ins) ->
+            if(ins.opcode== Opcode.SEC || ins.opcode== Opcode.CLC) {
+                if(idx < chunk.lines.size-1) {
+                    val insAfter = chunk.lines[idx+1] as? IRCodeInstruction
+                    if(insAfter?.ins?.opcode == ins.opcode) {
+                        chunk.lines.removeAt(idx)
+                        changed = true
+                    }
+                    else if(ins.opcode== Opcode.SEC && insAfter?.ins?.opcode== Opcode.CLC) {
+                        chunk.lines.removeAt(idx)
+                        changed = true
+                    }
+                    else if(ins.opcode== Opcode.CLC && insAfter?.ins?.opcode== Opcode.SEC) {
+                        chunk.lines.removeAt(idx)
+                        changed = true
+                    }
+                }
+            }
+        }
+        return changed
+    }
+
+    private fun removeWeirdBranches(chunk: IRCodeChunk, indexedInstructions: List<IndexedValue<Instruction>>): Boolean {
+        //  jump/branch to label immediately below
+        var changed = false
+        indexedInstructions.reversed().forEach { (idx, ins) ->
+            val labelSymbol = ins.labelSymbol
+            if(ins.opcode== Opcode.JUMP && labelSymbol!=null) {
+                // if jumping to label immediately following this
+                if(idx < chunk.lines.size-1) {
+                    val label = chunk.lines[idx+1] as? IRCodeLabel
+                    if(labelSymbol.size==1 && label?.name == labelSymbol[0]) {
+                        chunk.lines.removeAt(idx)
+                        changed = true
+                    }
+                }
+            }
+        }
+        return changed
+    }
+
+    private fun removeUselessArithmetic(chunk: IRCodeChunk, indexedInstructions: List<IndexedValue<Instruction>>): Boolean {
+        // note: this is hard to solve for the non-immediate instructions atm because the values are loaded into registers first
+        var changed = false
+        indexedInstructions.reversed().forEach { (idx, ins) ->
+            when (ins.opcode) {
+                Opcode.DIV, Opcode.DIVS, Opcode.MUL, Opcode.MOD -> {
+                    if (ins.value == 1) {
+                        chunk.lines.removeAt(idx)
+                        changed = true
+                    }
+                }
+                Opcode.ADD, Opcode.SUB -> {
+                    if (ins.value == 1) {
+                        chunk.lines[idx] = IRCodeInstruction(
+                            if (ins.opcode == Opcode.ADD) Opcode.INC else Opcode.DEC,
+                            ins.type,
+                            ins.reg1
+                        )
+                        changed = true
+                    } else if (ins.value == 0) {
+                        chunk.lines.removeAt(idx)
+                        changed = true
+                    }
+                }
+                Opcode.AND -> {
+                    if (ins.value == 0) {
+                        chunk.lines[idx] = IRCodeInstruction(Opcode.LOAD, ins.type, reg1 = ins.reg1, value = 0)
+                        changed = true
+                    } else if (ins.value == 255 && ins.type == VmDataType.BYTE) {
+                        chunk.lines.removeAt(idx)
+                        changed = true
+                    } else if (ins.value == 65535 && ins.type == VmDataType.WORD) {
+                        chunk.lines.removeAt(idx)
+                        changed = true
+                    }
+                }
+                Opcode.OR -> {
+                    if (ins.value == 0) {
+                        chunk.lines.removeAt(idx)
+                        changed = true
+                    } else if ((ins.value == 255 && ins.type == VmDataType.BYTE) || (ins.value == 65535 && ins.type == VmDataType.WORD)) {
+                        chunk.lines[idx] = IRCodeInstruction(Opcode.LOAD, ins.type, reg1 = ins.reg1, value = ins.value)
+                        changed = true
+                    }
+                }
+                Opcode.XOR -> {
+                    if (ins.value == 0) {
+                        chunk.lines.removeAt(idx)
+                        changed = true
+                    }
+                }
+                else -> {}
+            }
+        }
+        return changed
+    }
+
+    private fun removeNops(chunk: IRCodeChunk, indexedInstructions: List<IndexedValue<Instruction>>): Boolean {
+        var changed = false
+        indexedInstructions.reversed().forEach { (idx, ins) ->
+            if (ins.opcode == Opcode.NOP) {
+                changed = true
+                chunk.lines.removeAt(idx)
+            }
+        }
+        return changed
+    }
+
+    private fun removeDoubleLoadsAndStores(chunk: IRCodeChunk, indexedInstructions: List<IndexedValue<Instruction>>): Boolean {
+        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
+    }
+}

codeGenIntermediate/src/prog8/codegen/intermediate/RegisterPool.kt

@@ -0,0 +1,27 @@
+package prog8.codegen.intermediate
+
+import prog8.code.core.AssemblyError
+
+internal class RegisterPool {
+    private var firstFree: Int=3        // integer registers 0,1,2 are reserved
+    private var firstFreeFloat: Int=0
+
+    fun peekNext() = firstFree
+    fun peekNextFloat() = firstFreeFloat
+
+    fun nextFree(): Int {
+        val result = firstFree
+        firstFree++
+        if(firstFree>65535)
+            throw AssemblyError("out of virtual registers (int)")
+        return result
+    }
+
+    fun nextFreeFloat(): Int {
+        val result = firstFreeFloat
+        firstFreeFloat++
+        if(firstFreeFloat>65535)
+            throw AssemblyError("out of virtual registers (fp)")
+        return result
+    }
+}

codeGenIntermediate/test/Dummies.kt

@@ -0,0 +1,20 @@
+import prog8.code.core.DataType
+import prog8.code.core.Encoding
+import prog8.code.core.IMemSizer
+import prog8.code.core.IStringEncoding
+
+
+internal object DummyMemsizer : IMemSizer {
+    override fun memorySize(dt: DataType) = 0
+    override fun memorySize(arrayDt: DataType, numElements: Int) = 0
+}
+
+internal object DummyStringEncoder : IStringEncoding {
+    override fun encodeString(str: String, encoding: Encoding): List<UByte> {
+        return emptyList()
+    }
+
+    override fun decodeString(bytes: List<UByte>, encoding: Encoding): String {
+        return ""
+    }
+}

codeGenIntermediate/test/TestIRPeepholeOpt.kt

@@ -0,0 +1,177 @@
+import io.kotest.core.spec.style.FunSpec
+import io.kotest.matchers.shouldBe
+import prog8.code.core.*
+import prog8.code.target.VMTarget
+import prog8.codegen.intermediate.IRPeepholeOptimizer
+import prog8.intermediate.*
+
+class TestIRPeepholeOpt: FunSpec({
+    fun makeIRProgram(lines: List<IRCodeLine>): IRProgram {
+        val block = IRBlock("main", null, IRBlock.BlockAlignment.NONE, Position.DUMMY)
+        val sub = IRSubroutine("main.start", emptyList(), null, Position.DUMMY)
+        val chunk = IRCodeChunk(Position.DUMMY)
+        for(line in lines)
+            chunk += line
+        sub += chunk
+        block += sub
+        val target = VMTarget()
+        val options = CompilationOptions(
+            OutputType.RAW,
+            CbmPrgLauncherType.NONE,
+            ZeropageType.DONTUSE,
+            emptyList(),
+            floats = false,
+            noSysInit = true,
+            compTarget = target,
+            loadAddress = target.machine.PROGRAM_LOAD_ADDRESS
+        )
+        val prog = IRProgram("test", IRSymbolTable(null), options, target)
+        prog.addBlock(block)
+        return prog
+    }
+
+    fun IRProgram.lines(): List<IRCodeLine> = this.blocks.flatMap { it.subroutines }.flatMap { it.chunks }.flatMap { it.lines }
+
+    test("remove nops") {
+        val irProg = makeIRProgram(listOf(
+            IRCodeInstruction(Opcode.JUMP, labelSymbol = "dummy"),
+            IRCodeInstruction(Opcode.NOP),
+            IRCodeInstruction(Opcode.NOP)
+        ))
+        irProg.lines().size shouldBe 3
+        val opt = IRPeepholeOptimizer(irProg)
+        opt.optimize()
+        irProg.lines().size shouldBe 1
+    }
+
+    test("remove jmp to label below") {
+        val irProg = makeIRProgram(listOf(
+            IRCodeInstruction(Opcode.JUMP, labelSymbol = "label"),  // removed
+            IRCodeLabel("label"),
+            IRCodeInstruction(Opcode.JUMP, labelSymbol = "label2"), // removed
+            IRCodeInstruction(Opcode.NOP),  // removed
+            IRCodeLabel("label2"),
+            IRCodeInstruction(Opcode.JUMP, labelSymbol = "label3"),
+            IRCodeInstruction(Opcode.INC, VmDataType.BYTE, reg1=1),
+            IRCodeLabel("label3")
+        ))
+        irProg.lines().size shouldBe 8
+        val opt = IRPeepholeOptimizer(irProg)
+        opt.optimize()
+        val lines = irProg.lines()
+        lines.size shouldBe 5
+        (lines[0] as IRCodeLabel).name shouldBe "label"
+        (lines[1] as IRCodeLabel).name shouldBe "label2"
+        (lines[2] as IRCodeInstruction).ins.opcode shouldBe Opcode.JUMP
+        (lines[3] as IRCodeInstruction).ins.opcode shouldBe Opcode.INC
+        (lines[4] as IRCodeLabel).name shouldBe "label3"
+    }
+
+    test("remove double sec/clc") {
+        val irProg = makeIRProgram(listOf(
+            IRCodeInstruction(Opcode.SEC),
+            IRCodeInstruction(Opcode.SEC),
+            IRCodeInstruction(Opcode.SEC),
+            IRCodeInstruction(Opcode.CLC),
+            IRCodeInstruction(Opcode.CLC),
+            IRCodeInstruction(Opcode.CLC)
+        ))
+        irProg.lines().size shouldBe 6
+        val opt = IRPeepholeOptimizer(irProg)
+        opt.optimize()
+        val lines = irProg.lines()
+        lines.size shouldBe 1
+        (lines[0] as IRCodeInstruction).ins.opcode shouldBe Opcode.CLC
+    }
+
+    test("push followed by pop") {
+        val irProg = makeIRProgram(listOf(
+            IRCodeInstruction(Opcode.PUSH, VmDataType.BYTE, reg1=42),
+            IRCodeInstruction(Opcode.POP, VmDataType.BYTE, reg1=42),
+            IRCodeInstruction(Opcode.PUSH, VmDataType.BYTE, reg1=99),
+            IRCodeInstruction(Opcode.POP, VmDataType.BYTE, reg1=222)
+        ))
+        irProg.lines().size shouldBe 4
+        val opt = IRPeepholeOptimizer(irProg)
+        opt.optimize()
+        val lines = irProg.lines()
+        lines.size shouldBe 1
+        (lines[0] as IRCodeInstruction).ins.opcode shouldBe Opcode.LOADR
+        (lines[0] as IRCodeInstruction).ins.reg1 shouldBe 222
+        (lines[0] as IRCodeInstruction).ins.reg2 shouldBe 99
+    }
+
+    test("remove useless div/mul, add/sub") {
+        val irProg = makeIRProgram(listOf(
+            IRCodeInstruction(Opcode.DIV, VmDataType.BYTE, reg1=42, value = 1),
+            IRCodeInstruction(Opcode.DIVS, VmDataType.BYTE, reg1=42, value = 1),
+            IRCodeInstruction(Opcode.MUL, VmDataType.BYTE, reg1=42, value = 1),
+            IRCodeInstruction(Opcode.MOD, VmDataType.BYTE, reg1=42, value = 1),
+            IRCodeInstruction(Opcode.DIV, VmDataType.BYTE, reg1=42, value = 2),
+            IRCodeInstruction(Opcode.DIVS, VmDataType.BYTE, reg1=42, value = 2),
+            IRCodeInstruction(Opcode.MUL, VmDataType.BYTE, reg1=42, value = 2),
+            IRCodeInstruction(Opcode.MOD, VmDataType.BYTE, reg1=42, value = 2),
+            IRCodeInstruction(Opcode.ADD, VmDataType.BYTE, reg1=42, value = 0),
+            IRCodeInstruction(Opcode.SUB, VmDataType.BYTE, reg1=42, value = 0)
+        ))
+        irProg.lines().size shouldBe 10
+        val opt = IRPeepholeOptimizer(irProg)
+        opt.optimize()
+        val lines = irProg.lines()
+        lines.size shouldBe 4
+    }
+
+    test("replace add/sub 1 by inc/dec") {
+        val irProg = makeIRProgram(listOf(
+            IRCodeInstruction(Opcode.ADD, VmDataType.BYTE, reg1=42, value = 1),
+            IRCodeInstruction(Opcode.SUB, VmDataType.BYTE, reg1=42, value = 1)
+        ))
+        irProg.lines().size shouldBe 2
+        val opt = IRPeepholeOptimizer(irProg)
+        opt.optimize()
+        val lines = irProg.lines()
+        lines.size shouldBe 2
+        (lines[0] as IRCodeInstruction).ins.opcode shouldBe Opcode.INC
+        (lines[1] as IRCodeInstruction).ins.opcode shouldBe Opcode.DEC
+    }
+
+    test("remove useless and/or/xor") {
+        val irProg = makeIRProgram(listOf(
+            IRCodeInstruction(Opcode.AND, VmDataType.BYTE, reg1=42, value = 255),
+            IRCodeInstruction(Opcode.AND, VmDataType.WORD, reg1=42, value = 65535),
+            IRCodeInstruction(Opcode.OR, VmDataType.BYTE, reg1=42, value = 0),
+            IRCodeInstruction(Opcode.XOR, VmDataType.BYTE, reg1=42, value = 0),
+            IRCodeInstruction(Opcode.AND, VmDataType.BYTE, reg1=42, value = 200),
+            IRCodeInstruction(Opcode.AND, VmDataType.WORD, reg1=42, value = 60000),
+            IRCodeInstruction(Opcode.OR, VmDataType.BYTE, reg1=42, value = 1),
+            IRCodeInstruction(Opcode.XOR, VmDataType.BYTE, reg1=42, value = 1)
+        ))
+        irProg.lines().size shouldBe 8
+        val opt = IRPeepholeOptimizer(irProg)
+        opt.optimize()
+        val lines = irProg.lines()
+        lines.size shouldBe 4
+    }
+
+    test("replace and/or/xor by constant number") {
+        val irProg = makeIRProgram(listOf(
+            IRCodeInstruction(Opcode.AND, VmDataType.BYTE, reg1=42, value = 0),
+            IRCodeInstruction(Opcode.AND, VmDataType.WORD, reg1=42, value = 0),
+            IRCodeInstruction(Opcode.OR, VmDataType.BYTE, reg1=42, value = 255),
+            IRCodeInstruction(Opcode.OR, VmDataType.WORD, reg1=42, value = 65535)
+        ))
+        irProg.lines().size shouldBe 4
+        val opt = IRPeepholeOptimizer(irProg)
+        opt.optimize()
+        val lines = irProg.lines()
+        lines.size shouldBe 4
+        (lines[0] as IRCodeInstruction).ins.opcode shouldBe Opcode.LOAD
+        (lines[1] as IRCodeInstruction).ins.opcode shouldBe Opcode.LOAD
+        (lines[2] as IRCodeInstruction).ins.opcode shouldBe Opcode.LOAD
+        (lines[3] as IRCodeInstruction).ins.opcode shouldBe Opcode.LOAD
+        (lines[0] as IRCodeInstruction).ins.value shouldBe 0
+        (lines[1] as IRCodeInstruction).ins.value shouldBe 0
+        (lines[2] as IRCodeInstruction).ins.value shouldBe 255
+        (lines[3] as IRCodeInstruction).ins.value shouldBe 65535
+    }
+})

codeGenVirtual/build.gradle

@@ -3,6 +3,7 @@ plugins {
     id 'java'
     id 'application'
     id "org.jetbrains.kotlin.jvm"
+    id "io.kotest" version "0.3.9"
 }
 
 java {
@@ -24,13 +25,15 @@ compileTestKotlin {
 }
 
 dependencies {
-    implementation project(':virtualmachine')
-    implementation project(':codeAst')
     implementation project(':codeCore')
+    implementation project(':intermediate')
+    implementation project(':codeGenIntermediate')
+    implementation project(':virtualmachine')
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
     // implementation "org.jetbrains.kotlin:kotlin-reflect"
-    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.14"
+    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.16"
 
+    testImplementation 'io.kotest:kotest-runner-junit5-jvm:5.3.2'
 }
 
 sourceSets {
@@ -42,6 +45,22 @@ sourceSets {
             srcDirs = ["${project.projectDir}/res"]
         }
     }
+    test {
+        java {
+            srcDir "${project.projectDir}/test"
+        }
+    }
 }
 
-// note: there are no unit tests in this module!
+test {
+    // Enable JUnit 5 (Gradle 4.6+).
+    useJUnitPlatform()
+
+    // Always run tests, even when nothing changed.
+    dependsOn 'cleanTest'
+
+    // Show test results.
+    testLogging {
+        events "skipped", "failed"
+    }
+}

codeGenVirtual/codeGenVirtual.iml

@@ -4,13 +4,18 @@
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/test" isTestSource="true" />
+      <excludeFolder url="file://$MODULE_DIR$/build" />
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="library" name="KotlinJavaRuntime" level="project" />
     <orderEntry type="library" name="michael.bull.kotlin.result.jvm" level="project" />
-    <orderEntry type="module" module-name="codeAst" />
+    <orderEntry type="library" name="io.kotest.assertions.core.jvm" level="project" />
+    <orderEntry type="library" name="io.kotest.runner.junit5.jvm" level="project" />
     <orderEntry type="module" module-name="codeCore" />
+    <orderEntry type="module" module-name="intermediate" />
+    <orderEntry type="module" module-name="codeGenIntermediate" />
     <orderEntry type="module" module-name="virtualmachine" />
   </component>
 </module>

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

@@ -1,138 +0,0 @@
-package prog8.codegen.virtual
-
-import prog8.code.core.AssemblyError
-import prog8.code.core.CompilationOptions
-import prog8.code.core.IAssemblyProgram
-import prog8.vm.Instruction
-import prog8.vm.Opcode
-import prog8.vm.OpcodesWithAddress
-import prog8.vm.VmDataType
-import java.io.BufferedWriter
-import java.nio.file.Path
-import kotlin.io.path.bufferedWriter
-import kotlin.io.path.div
-
-
-internal class AssemblyProgram(override val name: String,
-                               private val allocations: VariableAllocator
-) : IAssemblyProgram {
-
-    private val globalInits = mutableListOf<VmCodeLine>()
-    private val blocks = mutableListOf<VmCodeChunk>()
-
-    override fun assemble(options: CompilationOptions): Boolean {
-        val outfile = options.outputDir / ("$name.p8virt")
-        println("write code to $outfile")
-        outfile.bufferedWriter().use { out ->
-            allocations.asVmMemory().forEach { (name, alloc) ->
-                out.write("; ${name.joinToString(".")}\n")
-                out.write(alloc + "\n")
-            }
-            out.write("------PROGRAM------\n")
-
-            if(!options.dontReinitGlobals) {
-                out.write("; global var inits\n")
-                globalInits.forEach { out.writeLine(it) }
-            }
-
-            out.write("; actual program code\n")
-            blocks.asSequence().flatMap { it.lines }.forEach { line->out.writeLine(line) }
-        }
-        return true
-    }
-
-    private fun BufferedWriter.writeLine(line: VmCodeLine) {
-        when(line) {
-            is VmCodeComment -> write("; ${line.comment}\n")
-            is VmCodeInstruction -> {
-                write(line.ins.toString() + "\n")
-            }
-            is VmCodeLabel -> write("_" + line.name.joinToString(".") + ":\n")
-            is VmCodeInlineAsm -> {
-                val asm = line.assembly.replace("""\{[a-zA-Z\d_\.]+\}""".toRegex()) { matchResult ->
-                    val name = matchResult.value.substring(1, matchResult.value.length-1).split('.')
-                    allocations.get(name).toString() }
-                write(asm+"\n")
-            }
-            is VmCodeInlineBinary -> {
-                write("incbin \"${line.file}\"")
-                if(line.offset!=null)
-                    write(",${line.offset}")
-                if(line.length!=null)
-                    write(",${line.length}")
-                write("\n")
-            }
-            else -> throw AssemblyError("invalid vm code line")
-        }
-    }
-
-    fun addGlobalInits(chunk: VmCodeChunk) = globalInits.addAll(chunk.lines)
-    fun addBlock(block: VmCodeChunk) = blocks.add(block)
-}
-
-internal sealed class VmCodeLine
-
-internal class VmCodeInstruction(
-    opcode: Opcode,
-    type: VmDataType?=null,
-    reg1: Int?=null,        // 0-$ffff
-    reg2: Int?=null,        // 0-$ffff
-    fpReg1: Int?=null,      // 0-$ffff
-    fpReg2: Int?=null,      // 0-$ffff
-    value: Int?=null,       // 0-$ffff
-    fpValue: Float?=null,
-    labelSymbol: List<String>?=null    // alternative to value for branch/call/jump labels
-    ): VmCodeLine() {
-        val ins = Instruction(opcode, type, reg1, reg2, fpReg1, fpReg2, value, fpValue, labelSymbol)
-
-        init {
-            if(reg1!=null && (reg1<0 || reg1>65536))
-                throw IllegalArgumentException("reg1 out of bounds")
-            if(reg2!=null && (reg2<0 || reg2>65536))
-                throw IllegalArgumentException("reg2 out of bounds")
-            if(fpReg1!=null && (fpReg1<0 || fpReg1>65536))
-                throw IllegalArgumentException("fpReg1 out of bounds")
-            if(fpReg2!=null && (fpReg2<0 || fpReg2>65536))
-                throw IllegalArgumentException("fpReg2 out of bounds")
-
-            if(value!=null && opcode !in OpcodesWithAddress) {
-                when (type) {
-                    VmDataType.BYTE -> {
-                        if (value < -128 || value > 255)
-                            throw IllegalArgumentException("value out of range for byte: $value")
-                    }
-                    VmDataType.WORD -> {
-                        if (value < -32768 || value > 65535)
-                            throw IllegalArgumentException("value out of range for word: $value")
-                    }
-                    VmDataType.FLOAT, null -> {}
-                }
-            }
-        }
-    }
-
-internal class VmCodeLabel(val name: List<String>): VmCodeLine()
-internal class VmCodeComment(val comment: String): VmCodeLine()
-
-internal class VmCodeChunk(initial: VmCodeLine? = null) {
-    val lines = mutableListOf<VmCodeLine>()
-
-    init {
-        if(initial!=null)
-            lines.add(initial)
-    }
-
-    operator fun plusAssign(line: VmCodeLine) {
-        lines.add(line)
-    }
-
-    operator fun plusAssign(chunk: VmCodeChunk) {
-        lines.addAll(chunk.lines)
-    }
-}
-
-internal class VmCodeInlineAsm(asm: String): VmCodeLine() {
-    val assembly: String = asm.trimIndent()
-}
-
-internal class VmCodeInlineBinary(val file: Path, val offset: UInt?, val length: UInt?): VmCodeLine()

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

@@ -1,232 +0,0 @@
-package prog8.codegen.virtual
-
-import prog8.code.ast.*
-import prog8.code.core.AssemblyError
-import prog8.code.core.DataType
-import prog8.code.core.SignedDatatypes
-import prog8.vm.Opcode
-import prog8.vm.VmDataType
-
-internal class AssignmentGen(private val codeGen: CodeGen, private val expressionEval: ExpressionGen) {
-
-    internal fun translate(assignment: PtAssignment): VmCodeChunk {
-        if(assignment.target.children.single() is PtMachineRegister)
-            throw AssemblyError("assigning to a register should be done by just evaluating the expression into resultregister")
-
-        return if (assignment.isInplaceAssign)
-            translateInplaceAssign(assignment)
-        else
-            translateRegularAssign(assignment)
-    }
-
-    private fun translateInplaceAssign(assignment: PtAssignment): VmCodeChunk {
-        val ident = assignment.target.identifier
-        val memory = assignment.target.memory
-        val array = assignment.target.array
-
-        return if(ident!=null) {
-            val address = codeGen.allocations.get(ident.targetName)
-            assignSelfInMemory(address, assignment.value, assignment)
-        } else if(memory != null) {
-            if(memory.address is PtNumber)
-                assignSelfInMemory((memory.address as PtNumber).number.toInt(), assignment.value, assignment)
-            else
-                fallbackAssign(assignment)
-        } else if(array!=null) {
-            // TODO in-place array element assignment?
-            fallbackAssign(assignment)
-        } else {
-            fallbackAssign(assignment)
-        }
-    }
-
-    private fun assignSelfInMemory(
-        address: Int,
-        value: PtExpression,
-        origAssign: PtAssignment
-    ): VmCodeChunk {
-        val vmDt = codeGen.vmType(value.type)
-        val code = VmCodeChunk()
-        when(value) {
-            is PtIdentifier -> return code // do nothing, x=x null assignment.
-            is PtMachineRegister -> return code // do nothing, reg=reg null assignment
-            is PtPrefix -> return inplacePrefix(value.operator, vmDt, address)
-            is PtBinaryExpression -> return inplaceBinexpr(value.operator, value.right, vmDt, value.type in SignedDatatypes, address, origAssign)
-            is PtMemoryByte -> {
-                return if (!codeGen.options.compTarget.machine.isIOAddress(address.toUInt()))
-                    code // do nothing, mem=mem null assignment.
-                else {
-                    // read and write a (i/o) memory location to itself.
-                    val tempReg = codeGen.vmRegisters.nextFree()
-                    code += VmCodeInstruction(Opcode.LOADM, vmDt, reg1 = tempReg, value = address)
-                    code += VmCodeInstruction(Opcode.STOREM, vmDt, reg1 = tempReg, value = address)
-                    code
-                }
-            }
-            else -> return fallbackAssign(origAssign)
-        }
-
-    }
-
-    private fun fallbackAssign(origAssign: PtAssignment): VmCodeChunk {
-        if (codeGen.options.slowCodegenWarnings)
-            codeGen.errors.warn("indirect code for in-place assignment", origAssign.position)
-        return translateRegularAssign(origAssign)
-    }
-
-    private fun inplaceBinexpr(
-        operator: String,
-        operand: PtExpression,
-        vmDt: VmDataType,
-        signed: Boolean,
-        address: Int,
-        origAssign: PtAssignment
-    ): VmCodeChunk {
-        when(operator) {
-            "+" -> return expressionEval.operatorPlusInplace(address, vmDt, operand)
-            "-" -> return expressionEval.operatorMinusInplace(address, vmDt, operand)
-            "*" -> return expressionEval.operatorMultiplyInplace(address, vmDt, operand)
-            "/" -> return expressionEval.operatorDivideInplace(address, vmDt, signed, operand)
-            "|" -> return expressionEval.operatorOrInplace(address, vmDt, operand)
-            "&" -> return expressionEval.operatorAndInplace(address, vmDt, operand)
-            "^" -> return expressionEval.operatorXorInplace(address, vmDt, operand)
-            "<<" -> return expressionEval.operatorShiftLeftInplace(address, vmDt, operand)
-            ">>" -> return expressionEval.operatorShiftRightInplace(address, vmDt, signed, operand)
-            else -> {}
-        }
-        return fallbackAssign(origAssign)
-    }
-
-    private fun inplacePrefix(operator: String, vmDt: VmDataType, address: Int): VmCodeChunk {
-        val code= VmCodeChunk()
-        when(operator) {
-            "+" -> { }
-            "-" -> {
-                code += VmCodeInstruction(Opcode.NEGM, vmDt, value = address)
-            }
-            "~" -> {
-                val regMask = codeGen.vmRegisters.nextFree()
-                val mask = if(vmDt==VmDataType.BYTE) 0x00ff else 0xffff
-                code += VmCodeInstruction(Opcode.LOAD, vmDt, reg1=regMask, value = mask)
-                code += VmCodeInstruction(Opcode.XORM, vmDt, reg1=regMask, value = address)
-            }
-            "not" -> {
-                code += VmCodeInstruction(Opcode.NOTM, vmDt, value = address)
-            }
-            else -> throw AssemblyError("weird prefix operator")
-        }
-        return code
-    }
-
-    private fun translateRegularAssign(assignment: PtAssignment): VmCodeChunk {
-        // note: assigning array and string values is done via an explicit memcopy/stringcopy function call.
-        val ident = assignment.target.identifier
-        val memory = assignment.target.memory
-        val array = assignment.target.array
-        val vmDt = codeGen.vmType(assignment.value.type)
-
-        val code = VmCodeChunk()
-        var resultRegister = -1
-        var resultFpRegister = -1
-        val zero = codeGen.isZero(assignment.value)
-        if(!zero) {
-            // calculate the assignment value
-            if (vmDt == VmDataType.FLOAT) {
-                resultFpRegister = codeGen.vmRegisters.nextFreeFloat()
-                code += expressionEval.translateExpression(assignment.value, -1, resultFpRegister)
-            } else {
-                resultRegister = if (assignment.value is PtMachineRegister) {
-                    (assignment.value as PtMachineRegister).register
-                } else {
-                    val reg = codeGen.vmRegisters.nextFree()
-                    code += expressionEval.translateExpression(assignment.value, reg, -1)
-                    reg
-                }
-            }
-        }
-        if(ident!=null) {
-            val address = codeGen.allocations.get(ident.targetName)
-            code += if(zero) {
-                VmCodeInstruction(Opcode.STOREZM, vmDt, value = address)
-            } else {
-                if (vmDt == VmDataType.FLOAT)
-                    VmCodeInstruction(Opcode.STOREM, vmDt, fpReg1 = resultFpRegister, value = address)
-                else
-                    VmCodeInstruction(Opcode.STOREM, vmDt, reg1 = resultRegister, value = address)
-            }
-        }
-        else if(array!=null) {
-            val variable = array.variable.targetName
-            var variableAddr = codeGen.allocations.get(variable)
-            val itemsize = codeGen.program.memsizer.memorySize(array.type)
-            val fixedIndex = constIntValue(array.index)
-            if(zero) {
-                if(fixedIndex!=null) {
-                    variableAddr += fixedIndex*itemsize
-                    code += VmCodeInstruction(Opcode.STOREZM, vmDt, value=variableAddr)
-                } else {
-                    val indexReg = codeGen.vmRegisters.nextFree()
-                    code += loadIndexReg(array, itemsize, indexReg)
-                    code += VmCodeInstruction(Opcode.STOREZX, vmDt, reg1=indexReg, value=variableAddr)
-                }
-            } else {
-                if(vmDt== VmDataType.FLOAT) {
-                    if(fixedIndex!=null) {
-                        variableAddr += fixedIndex*itemsize
-                        code += VmCodeInstruction(Opcode.STOREM, vmDt, fpReg1 = resultFpRegister, value=variableAddr)
-                    } else {
-                        val indexReg = codeGen.vmRegisters.nextFree()
-                        code += loadIndexReg(array, itemsize, indexReg)
-                        code += VmCodeInstruction(Opcode.STOREX, vmDt, reg1 = resultRegister, reg2=indexReg, value=variableAddr)
-                    }
-                } else {
-                    if(fixedIndex!=null) {
-                        variableAddr += fixedIndex*itemsize
-                        code += VmCodeInstruction(Opcode.STOREM, vmDt, reg1 = resultRegister, value=variableAddr)
-                    } else {
-                        val indexReg = codeGen.vmRegisters.nextFree()
-                        code += loadIndexReg(array, itemsize, indexReg)
-                        code += VmCodeInstruction(Opcode.STOREX, vmDt, reg1 = resultRegister, reg2=indexReg, value=variableAddr)
-                    }
-                }
-            }
-        }
-        else if(memory!=null) {
-            require(vmDt== VmDataType.BYTE)
-            if(zero) {
-                if(memory.address is PtNumber) {
-                    code += VmCodeInstruction(Opcode.STOREZM, vmDt, value=(memory.address as PtNumber).number.toInt())
-                } else {
-                    val addressReg = codeGen.vmRegisters.nextFree()
-                    code += expressionEval.translateExpression(memory.address, addressReg, -1)
-                    code += VmCodeInstruction(Opcode.STOREZI, vmDt, reg1=addressReg)
-                }
-            } else {
-                if(memory.address is PtNumber) {
-                    code += VmCodeInstruction(Opcode.STOREM, vmDt, reg1=resultRegister, value=(memory.address as PtNumber).number.toInt())
-                } else {
-                    val addressReg = codeGen.vmRegisters.nextFree()
-                    code += expressionEval.translateExpression(memory.address, addressReg, -1)
-                    code += VmCodeInstruction(Opcode.STOREI, vmDt, reg1=resultRegister, reg2=addressReg)
-                }
-            }
-        }
-        else
-            throw AssemblyError("weird assigntarget")
-        return code
-    }
-
-    private fun loadIndexReg(array: PtArrayIndexer, itemsize: Int, indexReg: Int): VmCodeChunk {
-        val code = VmCodeChunk()
-        if(itemsize==1) {
-            code += expressionEval.translateExpression(array.index, indexReg, -1)
-        }
-        else {
-            val mult = PtBinaryExpression("*", DataType.UBYTE, array.position)
-            mult.children += array.index
-            mult.children += PtNumber(DataType.UBYTE, itemsize.toDouble(), array.position)
-            code += expressionEval.translateExpression(mult, indexReg, -1)
-        }
-        return code
-    }
-}

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

@@ -1,832 +0,0 @@
-package prog8.codegen.virtual
-
-import prog8.code.StStaticVariable
-import prog8.code.SymbolTable
-import prog8.code.ast.*
-import prog8.code.core.*
-import prog8.vm.Opcode
-import prog8.vm.VmDataType
-import kotlin.math.pow
-
-
-internal class VmRegisterPool {
-    private var firstFree: Int=3        // integer registers 0,1,2 are reserved
-    private var firstFreeFloat: Int=0
-
-    fun peekNext() = firstFree
-    fun peekNextFloat() = firstFreeFloat
-
-    fun nextFree(): Int {
-        val result = firstFree
-        firstFree++
-        if(firstFree>65535)
-            throw AssemblyError("out of virtual registers (int)")
-        return result
-    }
-
-    fun nextFreeFloat(): Int {
-        val result = firstFreeFloat
-        firstFreeFloat++
-        if(firstFreeFloat>65535)
-            throw AssemblyError("out of virtual registers (fp)")
-        return result
-    }
-}
-
-
-class CodeGen(internal val program: PtProgram,
-              internal val symbolTable: SymbolTable,
-              internal val options: CompilationOptions,
-              internal val errors: IErrorReporter
-): IAssemblyGenerator {
-
-    internal val allocations = VariableAllocator(symbolTable, program, errors)
-    private val expressionEval = ExpressionGen(this)
-    private val builtinFuncGen = BuiltinFuncGen(this, expressionEval)
-    private val assignmentGen = AssignmentGen(this, expressionEval)
-    internal val vmRegisters = VmRegisterPool()
-
-    override fun compileToAssembly(): IAssemblyProgram? {
-        val vmprog = AssemblyProgram(program.name, allocations)
-
-        if(!options.dontReinitGlobals) {
-            // collect global variables initializers
-            program.allBlocks().forEach {
-                val code = VmCodeChunk()
-                it.children.filterIsInstance<PtAssignment>().forEach { assign -> code += assignmentGen.translate(assign) }
-                vmprog.addGlobalInits(code)
-            }
-        }
-
-        for (block in program.allBlocks()) {
-            vmprog.addBlock(translate(block))
-        }
-
-        println("Vm codegen: amount of vm registers=${vmRegisters.peekNext()}")
-
-        return vmprog
-    }
-
-
-    internal fun translateNode(node: PtNode): VmCodeChunk {
-        val code = when(node) {
-            is PtBlock -> translate(node)
-            is PtSub -> translate(node)
-            is PtScopeVarsDecls -> VmCodeChunk() // vars should be looked up via symbol table
-            is PtVariable -> VmCodeChunk() // var should be looked up via symbol table
-            is PtMemMapped -> VmCodeChunk() // memmapped var should be looked up via symbol table
-            is PtConstant -> VmCodeChunk() // constants have all been folded into the code
-            is PtAssignment -> assignmentGen.translate(node)
-            is PtNodeGroup -> translateGroup(node.children)
-            is PtBuiltinFunctionCall -> translateBuiltinFunc(node, 0)
-            is PtFunctionCall -> expressionEval.translate(node, 0, 0)
-            is PtNop -> VmCodeChunk()
-            is PtReturn -> translate(node)
-            is PtJump -> translate(node)
-            is PtWhen -> translate(node)
-            is PtPipe -> expressionEval.translate(node, 0)
-            is PtForLoop -> translate(node)
-            is PtIfElse -> translate(node)
-            is PtPostIncrDecr -> translate(node)
-            is PtRepeatLoop -> translate(node)
-            is PtLabel -> VmCodeChunk(VmCodeLabel(node.scopedName))
-            is PtBreakpoint -> VmCodeChunk(VmCodeInstruction(Opcode.BREAKPOINT))
-            is PtConditionalBranch -> translate(node)
-            is PtInlineAssembly -> VmCodeChunk(VmCodeInlineAsm(node.assembly))
-            is PtIncludeBinary -> VmCodeChunk(VmCodeInlineBinary(node.file, node.offset, node.length))
-            is PtAsmSub -> TODO("asmsub not yet supported on virtual machine target ${node.position}")
-            is PtAddressOf,
-            is PtContainmentCheck,
-            is PtMemoryByte,
-            is PtProgram,
-            is PtArrayIndexer,
-            is PtBinaryExpression,
-            is PtIdentifier,
-            is PtWhenChoice,
-            is PtPrefix,
-            is PtRange,
-            is PtAssignTarget,
-            is PtTypeCast,
-            is PtSubroutineParameter,
-            is PtNumber,
-            is PtArray,
-            is PtString -> throw AssemblyError("should not occur as separate statement node ${node.position}")
-            else -> TODO("missing codegen for $node")
-        }
-        if(code.lines.isNotEmpty() && node.position.line!=0)
-            code.lines.add(0, VmCodeComment(node.position.toString()))
-        return code
-    }
-
-    private fun translate(branch: PtConditionalBranch): VmCodeChunk {
-        val code = VmCodeChunk()
-        val elseLabel = createLabelName()
-        // note that the branch opcode used is the opposite as the branch condition, because the generated code jumps to the 'else' part
-        code += when(branch.condition) {
-            BranchCondition.CS -> VmCodeInstruction(Opcode.BSTCC, labelSymbol = elseLabel)
-            BranchCondition.CC -> VmCodeInstruction(Opcode.BSTCS, labelSymbol = elseLabel)
-            BranchCondition.EQ, BranchCondition.Z -> VmCodeInstruction(Opcode.BSTNE, labelSymbol = elseLabel)
-            BranchCondition.NE, BranchCondition.NZ -> VmCodeInstruction(Opcode.BSTEQ, labelSymbol = elseLabel)
-            BranchCondition.MI, BranchCondition.NEG -> VmCodeInstruction(Opcode.BSTPOS, labelSymbol = elseLabel)
-            BranchCondition.PL, BranchCondition.POS -> VmCodeInstruction(Opcode.BSTNEG, labelSymbol = elseLabel)
-            BranchCondition.VC,
-            BranchCondition.VS -> throw AssemblyError("conditional branch ${branch.condition} not supported in vm target due to lack of cpu V flag ${branch.position}")
-        }
-        code += translateNode(branch.trueScope)
-        if(branch.falseScope.children.isNotEmpty()) {
-            val endLabel = createLabelName()
-            code += VmCodeInstruction(Opcode.JUMP, labelSymbol = endLabel)
-            code += VmCodeLabel(elseLabel)
-            code += translateNode(branch.falseScope)
-            code += VmCodeLabel(endLabel)
-        } else {
-            code += VmCodeLabel(elseLabel)
-        }
-        return code
-    }
-
-    private fun translate(whenStmt: PtWhen): VmCodeChunk {
-        if(whenStmt.choices.children.isEmpty())
-            return VmCodeChunk()
-        val code = VmCodeChunk()
-        val valueReg = vmRegisters.nextFree()
-        val choiceReg = vmRegisters.nextFree()
-        val valueDt = vmType(whenStmt.value.type)
-        code += expressionEval.translateExpression(whenStmt.value, valueReg, -1)
-        val choices = whenStmt.choices.children.map {it as PtWhenChoice }
-        val endLabel = createLabelName()
-        for (choice in choices) {
-            if(choice.isElse) {
-                code += translateNode(choice.statements)
-            } else {
-                val skipLabel = createLabelName()
-                val values = choice.values.children.map {it as PtNumber}
-                if(values.size==1) {
-                    code += VmCodeInstruction(Opcode.LOAD, valueDt, reg1=choiceReg, value=values[0].number.toInt())
-                    code += VmCodeInstruction(Opcode.BNE, valueDt, reg1=valueReg, reg2=choiceReg, labelSymbol = skipLabel)
-                    code += translateNode(choice.statements)
-                    if(choice.statements.children.last() !is PtReturn)
-                        code += VmCodeInstruction(Opcode.JUMP, labelSymbol = endLabel)
-                } else {
-                    val matchLabel = createLabelName()
-                    for (value in values) {
-                        code += VmCodeInstruction(Opcode.LOAD, valueDt, reg1=choiceReg, value=value.number.toInt())
-                        code += VmCodeInstruction(Opcode.BEQ, valueDt, reg1=valueReg, reg2=choiceReg, labelSymbol = matchLabel)
-                    }
-                    code += VmCodeInstruction(Opcode.JUMP, labelSymbol = skipLabel)
-                    code += VmCodeLabel(matchLabel)
-                    code += translateNode(choice.statements)
-                    if(choice.statements.children.last() !is PtReturn)
-                        code += VmCodeInstruction(Opcode.JUMP, labelSymbol = endLabel)
-                }
-                code += VmCodeLabel(skipLabel)
-            }
-        }
-        code += VmCodeLabel(endLabel)
-        return code
-    }
-
-    private fun translate(forLoop: PtForLoop): VmCodeChunk {
-        val loopvar = symbolTable.lookup(forLoop.variable.targetName) as StStaticVariable
-        val iterable = forLoop.iterable
-        val code = VmCodeChunk()
-        when(iterable) {
-            is PtRange -> {
-                if(iterable.from is PtNumber && iterable.to is PtNumber)
-                    code += translateForInConstantRange(forLoop, loopvar)
-                else
-                    code += translateForInNonConstantRange(forLoop, loopvar)
-            }
-            is PtIdentifier -> {
-                val arrayAddress = allocations.get(iterable.targetName)
-                val iterableVar = symbolTable.lookup(iterable.targetName) as StStaticVariable
-                val loopvarAddress = allocations.get(loopvar.scopedName)
-                val indexReg = vmRegisters.nextFree()
-                val tmpReg = vmRegisters.nextFree()
-                val loopLabel = createLabelName()
-                val endLabel = createLabelName()
-                if(iterableVar.dt==DataType.STR) {
-                    // iterate over a zero-terminated string
-                    code += VmCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=indexReg, value=0)
-                    code += VmCodeLabel(loopLabel)
-                    code += VmCodeInstruction(Opcode.LOADX, VmDataType.BYTE, reg1=tmpReg, reg2=indexReg, value = arrayAddress)
-                    code += VmCodeInstruction(Opcode.BZ, VmDataType.BYTE, reg1=tmpReg, labelSymbol = endLabel)
-                    code += VmCodeInstruction(Opcode.STOREM, VmDataType.BYTE, reg1=tmpReg, value = loopvarAddress)
-                    code += translateNode(forLoop.statements)
-                    code += VmCodeInstruction(Opcode.INC, VmDataType.BYTE, reg1=indexReg)
-                    code += VmCodeInstruction(Opcode.JUMP, labelSymbol = loopLabel)
-                    code += VmCodeLabel(endLabel)
-                } else {
-                    // iterate over array
-                    val elementDt = ArrayToElementTypes.getValue(iterable.type)
-                    val elementSize = program.memsizer.memorySize(elementDt)
-                    val lengthBytes = iterableVar.length!! * elementSize
-                    if(lengthBytes<256) {
-                        val lengthReg = vmRegisters.nextFree()
-                        code += VmCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=indexReg, value=0)
-                        code += VmCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=lengthReg, value=lengthBytes)
-                        code += VmCodeLabel(loopLabel)
-                        code += VmCodeInstruction(Opcode.LOADX, vmType(elementDt), reg1=tmpReg, reg2=indexReg, value=arrayAddress)
-                        code += VmCodeInstruction(Opcode.STOREM, vmType(elementDt), reg1=tmpReg, value = loopvarAddress)
-                        code += translateNode(forLoop.statements)
-                        code += addConstReg(VmDataType.BYTE, indexReg, elementSize)
-                        code += VmCodeInstruction(Opcode.BNE, VmDataType.BYTE, reg1=indexReg, reg2=lengthReg, labelSymbol = loopLabel)
-                    } else if(lengthBytes==256) {
-                        code += VmCodeInstruction(Opcode.LOAD, VmDataType.BYTE, reg1=indexReg, value=0)
-                        code += VmCodeLabel(loopLabel)
-                        code += VmCodeInstruction(Opcode.LOADX, vmType(elementDt), reg1=tmpReg, reg2=indexReg, value=arrayAddress)
-                        code += VmCodeInstruction(Opcode.STOREM, vmType(elementDt), reg1=tmpReg, value = loopvarAddress)
-                        code += translateNode(forLoop.statements)
-                        code += addConstReg(VmDataType.BYTE, indexReg, elementSize)
-                        code += VmCodeInstruction(Opcode.BNZ, VmDataType.BYTE, reg1=indexReg, labelSymbol = loopLabel)
-                    } else {
-                        throw AssemblyError("iterator length should never exceed 256")
-                    }
-                }
-            }
-            else -> throw AssemblyError("weird for iterable")
-        }
-        return code
-    }
-
-    private fun translateForInNonConstantRange(forLoop: PtForLoop, loopvar: StStaticVariable): VmCodeChunk {
-        val iterable = forLoop.iterable as PtRange
-        val step = iterable.step.number.toInt()
-        if (step==0)
-            throw AssemblyError("step 0")
-        val indexReg = vmRegisters.nextFree()
-        val endvalueReg = vmRegisters.nextFree()
-        val loopvarAddress = allocations.get(loopvar.scopedName)
-        val loopvarDt = vmType(loopvar.dt)
-        val loopLabel = createLabelName()
-        val code = VmCodeChunk()
-
-        code += expressionEval.translateExpression(iterable.to, endvalueReg, -1)
-        code += expressionEval.translateExpression(iterable.from, indexReg, -1)
-        code += VmCodeInstruction(Opcode.STOREM, loopvarDt, reg1=indexReg, value=loopvarAddress)
-        code += VmCodeLabel(loopLabel)
-        code += translateNode(forLoop.statements)
-        if(step<3) {
-            code += addConstMem(loopvarDt, loopvarAddress.toUInt(), step)
-            code += VmCodeInstruction(Opcode.LOADM, loopvarDt, reg1 = indexReg, value = loopvarAddress)
-        } else {
-            code += VmCodeInstruction(Opcode.LOADM, loopvarDt, reg1 = indexReg, value = loopvarAddress)
-            code += addConstReg(loopvarDt, indexReg, step)
-            code += VmCodeInstruction(Opcode.STOREM, loopvarDt, reg1 = indexReg, value = loopvarAddress)
-        }
-        val branchOpcode = if(loopvar.dt in SignedDatatypes) Opcode.BLES else Opcode.BLE
-        code += VmCodeInstruction(branchOpcode, loopvarDt, reg1=indexReg, reg2=endvalueReg, labelSymbol=loopLabel)
-        return code
-    }
-
-    private fun translateForInConstantRange(forLoop: PtForLoop, loopvar: StStaticVariable): VmCodeChunk {
-        val loopLabel = createLabelName()
-        val loopvarAddress = allocations.get(loopvar.scopedName)
-        val indexReg = vmRegisters.nextFree()
-        val loopvarDt = vmType(loopvar.dt)
-        val iterable = forLoop.iterable as PtRange
-        val step = iterable.step.number.toInt()
-        val rangeStart = (iterable.from as PtNumber).number.toInt()
-        val rangeEndUntyped = (iterable.to as PtNumber).number.toInt() + step
-        if(step==0)
-            throw AssemblyError("step 0")
-        if(step>0 && rangeEndUntyped<rangeStart || step<0 && rangeEndUntyped>rangeStart)
-            throw AssemblyError("empty range")
-        val rangeEndWrapped = if(loopvarDt==VmDataType.BYTE) rangeEndUntyped and 255 else rangeEndUntyped and 65535
-        val code = VmCodeChunk()
-        val endvalueReg: Int
-        if(rangeEndWrapped!=0) {
-            endvalueReg = vmRegisters.nextFree()
-            code += VmCodeInstruction(Opcode.LOAD, loopvarDt, reg1 = endvalueReg, value = rangeEndWrapped)
-        } else {
-            endvalueReg = -1 // not used
-        }
-        code += VmCodeInstruction(Opcode.LOAD, loopvarDt, reg1=indexReg, value=rangeStart)
-        code += VmCodeInstruction(Opcode.STOREM, loopvarDt, reg1=indexReg, value=loopvarAddress)
-        code += VmCodeLabel(loopLabel)
-        code += translateNode(forLoop.statements)
-        if(step<3) {
-            code += addConstMem(loopvarDt, loopvarAddress.toUInt(), step)
-            code += VmCodeInstruction(Opcode.LOADM, loopvarDt, reg1 = indexReg, value = loopvarAddress)
-        } else {
-            code += VmCodeInstruction(Opcode.LOADM, loopvarDt, reg1 = indexReg, value = loopvarAddress)
-            code += addConstReg(loopvarDt, indexReg, step)
-            code += VmCodeInstruction(Opcode.STOREM, loopvarDt, reg1 = indexReg, value = loopvarAddress)
-        }
-        code += if(rangeEndWrapped==0) {
-            VmCodeInstruction(Opcode.BNZ, loopvarDt, reg1 = indexReg, labelSymbol = loopLabel)
-        } else {
-            VmCodeInstruction(Opcode.BNE, loopvarDt, reg1 = indexReg, reg2 = endvalueReg, labelSymbol = loopLabel)
-        }
-        return code
-    }
-
-    private fun addConstReg(dt: VmDataType, reg: Int, value: Int): VmCodeChunk {
-        val code = VmCodeChunk()
-        when(value) {
-            0 -> { /* do nothing */ }
-            1 -> {
-                code += VmCodeInstruction(Opcode.INC, dt, reg1=reg)
-            }
-            2 -> {
-                code += VmCodeInstruction(Opcode.INC, dt, reg1=reg)
-                code += VmCodeInstruction(Opcode.INC, dt, reg1=reg)
-            }
-            -1 -> {
-                code += VmCodeInstruction(Opcode.DEC, dt, reg1=reg)
-            }
-            -2 -> {
-                code += VmCodeInstruction(Opcode.DEC, dt, reg1=reg)
-                code += VmCodeInstruction(Opcode.DEC, dt, reg1=reg)
-            }
-            else -> {
-                val valueReg = vmRegisters.nextFree()
-                if(value>0) {
-                    code += VmCodeInstruction(Opcode.LOAD, dt, reg1=valueReg, value= value)
-                    code += VmCodeInstruction(Opcode.ADD, dt, reg1 = reg, reg2 = valueReg)
-                }
-                else {
-                    code += VmCodeInstruction(Opcode.LOAD, dt, reg1=valueReg, value= -value)
-                    code += VmCodeInstruction(Opcode.SUB, dt, reg1 = reg, reg2 = valueReg)
-                }
-            }
-        }
-        return code
-    }
-
-    private fun addConstMem(dt: VmDataType, address: UInt, value: Int): VmCodeChunk {
-        val code = VmCodeChunk()
-        when(value) {
-            0 -> { /* do nothing */ }
-            1 -> {
-                code += VmCodeInstruction(Opcode.INCM, dt, value=address.toInt())
-            }
-            2 -> {
-                code += VmCodeInstruction(Opcode.INCM, dt, value=address.toInt())
-                code += VmCodeInstruction(Opcode.INCM, dt, value=address.toInt())
-            }
-            -1 -> {
-                code += VmCodeInstruction(Opcode.DECM, dt, value=address.toInt())
-            }
-            -2 -> {
-                code += VmCodeInstruction(Opcode.DECM, dt, value=address.toInt())
-                code += VmCodeInstruction(Opcode.DECM, dt, value=address.toInt())
-            }
-            else -> {
-                val valueReg = vmRegisters.nextFree()
-                val operandReg = vmRegisters.nextFree()
-                if(value>0) {
-                    code += VmCodeInstruction(Opcode.LOADM, dt, reg1=valueReg, value=address.toInt())
-                    code += VmCodeInstruction(Opcode.LOAD, dt, reg1=operandReg, value=value)
-                    code += VmCodeInstruction(Opcode.ADD, dt, reg1 = valueReg, reg2 = operandReg)
-                    code += VmCodeInstruction(Opcode.STOREM, dt, reg1=valueReg, value=address.toInt())
-                }
-                else {
-                    code += VmCodeInstruction(Opcode.LOADM, dt, reg1=valueReg, value=address.toInt())
-                    code += VmCodeInstruction(Opcode.LOAD, dt, reg1=operandReg, value=-value)
-                    code += VmCodeInstruction(Opcode.SUB, dt, reg1 = valueReg, reg2 = operandReg)
-                    code += VmCodeInstruction(Opcode.STOREM, dt, reg1=valueReg, value=address.toInt())
-                }
-            }
-        }
-        return code
-    }
-
-    internal fun multiplyByConstFloat(fpReg: Int, factor: Float): VmCodeChunk {
-        val code = VmCodeChunk()
-        if(factor==1f)
-            return code
-        if(factor==0f) {
-            code += VmCodeInstruction(Opcode.LOAD, VmDataType.FLOAT, fpReg1 = fpReg, fpValue = 0f)
-        } else {
-            val factorReg = vmRegisters.nextFreeFloat()
-            code += VmCodeInstruction(Opcode.LOAD, VmDataType.FLOAT, fpReg1=factorReg, fpValue = factor)
-            code += VmCodeInstruction(Opcode.MUL, VmDataType.FLOAT, fpReg1 = fpReg, fpReg2 = factorReg)
-        }
-        return code
-    }
-
-    internal fun multiplyByConstFloatInplace(address: Int, factor: Float): VmCodeChunk {
-        val code = VmCodeChunk()
-        if(factor==1f)
-            return code
-        if(factor==0f) {
-            code += VmCodeInstruction(Opcode.STOREZM, VmDataType.FLOAT, value = address)
-        } else {
-            val factorReg = vmRegisters.nextFreeFloat()
-            code += VmCodeInstruction(Opcode.LOAD, VmDataType.FLOAT, fpReg1=factorReg, fpValue = factor)
-            code += VmCodeInstruction(Opcode.MULM, VmDataType.FLOAT, fpReg1 = factorReg, value = address)
-        }
-        return code
-    }
-
-    internal val powersOfTwo = (0..16).map { 2.0.pow(it.toDouble()).toInt() }
-
-    internal fun multiplyByConst(dt: VmDataType, reg: Int, factor: Int): VmCodeChunk {
-        val code = VmCodeChunk()
-        if(factor==1)
-            return code
-        val pow2 = powersOfTwo.indexOf(factor)
-        if(pow2==1) {
-            // just shift 1 bit
-            code += VmCodeInstruction(Opcode.LSL, dt, reg1=reg)
-        }
-        else if(pow2>=1) {
-            // just shift multiple bits
-            val pow2reg = vmRegisters.nextFree()
-            code += VmCodeInstruction(Opcode.LOAD, dt, reg1=pow2reg, value=pow2)
-            code += VmCodeInstruction(Opcode.LSLN, dt, reg1=reg, reg2=pow2reg)
-        } else {
-            if (factor == 0) {
-                code += VmCodeInstruction(Opcode.LOAD, dt, reg1=reg, value=0)
-            }
-            else {
-                val factorReg = vmRegisters.nextFree()
-                code += VmCodeInstruction(Opcode.LOAD, dt, reg1=factorReg, value= factor)
-                code += VmCodeInstruction(Opcode.MUL, dt, reg1=reg, reg2=factorReg)
-            }
-        }
-        return code
-    }
-
-    internal fun multiplyByConstInplace(dt: VmDataType, address: Int, factor: Int): VmCodeChunk {
-        val code = VmCodeChunk()
-        if(factor==1)
-            return code
-        val pow2 = powersOfTwo.indexOf(factor)
-        if(pow2==1) {
-            // just shift 1 bit
-            code += VmCodeInstruction(Opcode.LSLM, dt, value = address)
-        }
-        else if(pow2>=1) {
-            // just shift multiple bits
-            val pow2reg = vmRegisters.nextFree()
-            code += VmCodeInstruction(Opcode.LOAD, dt, reg1=pow2reg, value=pow2)
-            code += VmCodeInstruction(Opcode.LSLNM, dt, reg1=pow2reg, value=address)
-        } else {
-            if (factor == 0) {
-                code += VmCodeInstruction(Opcode.STOREZM, dt, value=address)
-            }
-            else {
-                val factorReg = vmRegisters.nextFree()
-                code += VmCodeInstruction(Opcode.LOAD, dt, reg1=factorReg, value = factor)
-                code += VmCodeInstruction(Opcode.MULM, dt, reg1=factorReg, value = address)
-            }
-        }
-        return code
-    }
-
-    internal fun divideByConstFloat(fpReg: Int, factor: Float): VmCodeChunk {
-        val code = VmCodeChunk()
-        if(factor==1f)
-            return code
-        if(factor==0f) {
-            code += VmCodeInstruction(Opcode.LOAD, VmDataType.FLOAT, fpReg1 = fpReg, fpValue = Float.MAX_VALUE)
-        } else {
-            val factorReg = vmRegisters.nextFreeFloat()
-            code += VmCodeInstruction(Opcode.LOAD, VmDataType.FLOAT, fpReg1=factorReg, fpValue = factor)
-            code += VmCodeInstruction(Opcode.DIVS, VmDataType.FLOAT, fpReg1 = fpReg, fpReg2 = factorReg)
-        }
-        return code
-    }
-
-    internal fun divideByConstFloatInplace(address: Int, factor: Float): VmCodeChunk {
-        val code = VmCodeChunk()
-        if(factor==1f)
-            return code
-        if(factor==0f) {
-            val maxvalueReg = vmRegisters.nextFreeFloat()
-            code += VmCodeInstruction(Opcode.LOAD, VmDataType.FLOAT, fpReg1 = maxvalueReg, fpValue = Float.MAX_VALUE)
-            code += VmCodeInstruction(Opcode.STOREM, VmDataType.FLOAT, fpReg1 = maxvalueReg, value=address)
-        } else {
-            val factorReg = vmRegisters.nextFreeFloat()
-            code += VmCodeInstruction(Opcode.LOAD, VmDataType.FLOAT, fpReg1=factorReg, fpValue = factor)
-            code += VmCodeInstruction(Opcode.DIVSM, VmDataType.FLOAT, fpReg1 = factorReg, value=address)
-        }
-        return code
-    }
-
-    internal fun divideByConst(dt: VmDataType, reg: Int, factor: Int, signed: Boolean): VmCodeChunk {
-        val code = VmCodeChunk()
-        if(factor==1)
-            return code
-        val pow2 = powersOfTwo.indexOf(factor)
-        if(pow2==1) {
-            // just shift 1 bit
-            code += if(signed)
-                VmCodeInstruction(Opcode.ASR, dt, reg1=reg)
-            else
-                VmCodeInstruction(Opcode.LSR, dt, reg1=reg)
-        }
-        else if(pow2>=1) {
-            // just shift multiple bits
-            val pow2reg = vmRegisters.nextFree()
-            code += VmCodeInstruction(Opcode.LOAD, dt, reg1=pow2reg, value=pow2)
-            code += if(signed)
-                VmCodeInstruction(Opcode.ASRN, dt, reg1=reg, reg2=pow2reg)
-            else
-                VmCodeInstruction(Opcode.LSRN, dt, reg1=reg, reg2=pow2reg)
-        } else {
-            if (factor == 0) {
-                code += VmCodeInstruction(Opcode.LOAD, dt, reg1=reg, value=0xffff)
-            }
-            else {
-                val factorReg = vmRegisters.nextFree()
-                code += VmCodeInstruction(Opcode.LOAD, dt, reg1=factorReg, value= factor)
-                code += if(signed)
-                    VmCodeInstruction(Opcode.DIVS, dt, reg1=reg, reg2=factorReg)
-                else
-                    VmCodeInstruction(Opcode.DIV, dt, reg1=reg, reg2=factorReg)
-            }
-        }
-        return code
-    }
-
-    internal fun divideByConstInplace(dt: VmDataType, address: Int, factor: Int, signed: Boolean): VmCodeChunk {
-        val code = VmCodeChunk()
-        if(factor==1)
-            return code
-        val pow2 = powersOfTwo.indexOf(factor)
-        if(pow2==1) {
-            // just shift 1 bit
-            code += if(signed)
-                VmCodeInstruction(Opcode.ASRM, dt, value=address)
-            else
-                VmCodeInstruction(Opcode.LSRM, dt, value=address)
-        }
-        else if(pow2>=1) {
-            // just shift multiple bits
-            val pow2reg = vmRegisters.nextFree()
-            code += VmCodeInstruction(Opcode.LOAD, dt, reg1=pow2reg, value=pow2)
-            code += if(signed)
-                VmCodeInstruction(Opcode.ASRNM, dt, reg1=pow2reg, value=address)
-            else
-                VmCodeInstruction(Opcode.LSRNM, dt, reg1=pow2reg, value=address)
-        } else {
-            if (factor == 0) {
-                val reg = vmRegisters.nextFree()
-                code += VmCodeInstruction(Opcode.LOAD, dt, reg1=reg, value=0xffff)
-                code += VmCodeInstruction(Opcode.STOREM, dt, reg1=reg, value=address)
-            }
-            else {
-                val factorReg = vmRegisters.nextFree()
-                code += VmCodeInstruction(Opcode.LOAD, dt, reg1=factorReg, value= factor)
-                code += if(signed)
-                    VmCodeInstruction(Opcode.DIVSM, dt, reg1=factorReg, value=address)
-                else
-                    VmCodeInstruction(Opcode.DIVM, dt, reg1=factorReg, value=address)
-            }
-        }
-        return code
-    }
-
-    private fun translate(ifElse: PtIfElse): VmCodeChunk {
-        if(ifElse.condition.operator !in ComparisonOperators)
-            throw AssemblyError("if condition should only be a binary comparison expression")
-
-        val signed = ifElse.condition.left.type in arrayOf(DataType.BYTE, DataType.WORD, DataType.FLOAT)
-        val vmDt = vmType(ifElse.condition.left.type)
-        val code = VmCodeChunk()
-
-        fun translateNonZeroComparison(): VmCodeChunk {
-            val elseBranch = when(ifElse.condition.operator) {
-                "==" -> Opcode.BNE
-                "!=" -> Opcode.BEQ
-                "<" -> if(signed) Opcode.BGES else Opcode.BGE
-                ">" -> if(signed) Opcode.BLES else Opcode.BLE
-                "<=" -> if(signed) Opcode.BGTS else Opcode.BGT
-                ">=" -> if(signed) Opcode.BLTS else Opcode.BLT
-                else -> throw AssemblyError("invalid comparison operator")
-            }
-
-            val leftReg = vmRegisters.nextFree()
-            val rightReg = vmRegisters.nextFree()
-            code += expressionEval.translateExpression(ifElse.condition.left, leftReg, -1)
-            code += expressionEval.translateExpression(ifElse.condition.right, rightReg, -1)
-            if(ifElse.elseScope.children.isNotEmpty()) {
-                // if and else parts
-                val elseLabel = createLabelName()
-                val afterIfLabel = createLabelName()
-                code += VmCodeInstruction(elseBranch, vmDt, reg1=leftReg, reg2=rightReg, labelSymbol = elseLabel)
-                code += translateNode(ifElse.ifScope)
-                code += VmCodeInstruction(Opcode.JUMP, labelSymbol = afterIfLabel)
-                code += VmCodeLabel(elseLabel)
-                code += translateNode(ifElse.elseScope)
-                code += VmCodeLabel(afterIfLabel)
-            } else {
-                // only if part
-                val afterIfLabel = createLabelName()
-                code += VmCodeInstruction(elseBranch, vmDt, reg1=leftReg, reg2=rightReg, labelSymbol = afterIfLabel)
-                code += translateNode(ifElse.ifScope)
-                code += VmCodeLabel(afterIfLabel)
-            }
-            return code
-        }
-
-        fun translateZeroComparison(): VmCodeChunk {
-            fun equalOrNotEqualZero(elseBranch: Opcode): VmCodeChunk {
-                val leftReg = vmRegisters.nextFree()
-                code += expressionEval.translateExpression(ifElse.condition.left, leftReg, -1)
-                if(ifElse.elseScope.children.isNotEmpty()) {
-                    // if and else parts
-                    val elseLabel = createLabelName()
-                    val afterIfLabel = createLabelName()
-                    code += VmCodeInstruction(elseBranch, vmDt, reg1=leftReg, labelSymbol = elseLabel)
-                    code += translateNode(ifElse.ifScope)
-                    code += VmCodeInstruction(Opcode.JUMP, labelSymbol = afterIfLabel)
-                    code += VmCodeLabel(elseLabel)
-                    code += translateNode(ifElse.elseScope)
-                    code += VmCodeLabel(afterIfLabel)
-                } else {
-                    // only if part
-                    val afterIfLabel = createLabelName()
-                    code += VmCodeInstruction(elseBranch, vmDt, reg1=leftReg, labelSymbol = afterIfLabel)
-                    code += translateNode(ifElse.ifScope)
-                    code += VmCodeLabel(afterIfLabel)
-                }
-                return code
-            }
-
-            return when (ifElse.condition.operator) {
-                "==" -> {
-                    // if X==0 ...   so we just branch on left expr is Not-zero.
-                    equalOrNotEqualZero(Opcode.BNZ)
-                }
-                "!=" -> {
-                    // if X!=0 ...   so we just branch on left expr is Zero.
-                    equalOrNotEqualZero(Opcode.BZ)
-                }
-                else -> {
-                    // another comparison against 0, just use regular codegen for this.
-                    translateNonZeroComparison()
-                }
-            }
-        }
-
-        return if(constValue(ifElse.condition.right)==0.0)
-            translateZeroComparison()
-        else
-            translateNonZeroComparison()
-    }
-
-
-    private fun translate(postIncrDecr: PtPostIncrDecr): VmCodeChunk {
-        val code = VmCodeChunk()
-        val operationMem: Opcode
-        val operationRegister: Opcode
-        when(postIncrDecr.operator) {
-            "++" -> {
-                operationMem = Opcode.INCM
-                operationRegister = Opcode.INC
-            }
-            "--" -> {
-                operationMem = Opcode.DECM
-                operationRegister = Opcode.DEC
-            }
-            else -> throw AssemblyError("weird operator")
-        }
-        val ident = postIncrDecr.target.identifier
-        val memory = postIncrDecr.target.memory
-        val array = postIncrDecr.target.array
-        val vmDt = vmType(postIncrDecr.target.type)
-        if(ident!=null) {
-            val address = allocations.get(ident.targetName)
-            code += VmCodeInstruction(operationMem, vmDt, value = address)
-        } else if(memory!=null) {
-            if(memory.address is PtNumber) {
-                val address = (memory.address as PtNumber).number.toInt()
-                code += VmCodeInstruction(operationMem, vmDt, value = address)
-            } else {
-                val incReg = vmRegisters.nextFree()
-                val addressReg = vmRegisters.nextFree()
-                code += expressionEval.translateExpression(memory.address, addressReg, -1)
-                code += VmCodeInstruction(Opcode.LOADI, vmDt, reg1 = incReg, reg2 = addressReg)
-                code += VmCodeInstruction(operationRegister, vmDt, reg1 = incReg)
-                code += VmCodeInstruction(Opcode.STOREI, vmDt, reg1 = incReg, reg2 = addressReg)
-            }
-        } else if (array!=null) {
-            val variable = array.variable.targetName
-            var variableAddr = allocations.get(variable)
-            val itemsize = program.memsizer.memorySize(array.type)
-            val fixedIndex = constIntValue(array.index)
-            if(fixedIndex!=null) {
-                variableAddr += fixedIndex*itemsize
-                code += VmCodeInstruction(operationMem, vmDt, value=variableAddr)
-            } else {
-                val incReg = vmRegisters.nextFree()
-                val indexReg = vmRegisters.nextFree()
-                code += expressionEval.translateExpression(array.index, indexReg, -1)
-                code += VmCodeInstruction(Opcode.LOADX, vmDt, reg1=incReg, reg2=indexReg, value=variableAddr)
-                code += VmCodeInstruction(operationRegister, vmDt, reg1=incReg)
-                code += VmCodeInstruction(Opcode.STOREX, vmDt, reg1=incReg, reg2=indexReg, value=variableAddr)
-            }
-        } else
-            throw AssemblyError("weird assigntarget")
-
-        return code
-    }
-
-    private fun translate(repeat: PtRepeatLoop): VmCodeChunk {
-        when (constIntValue(repeat.count)) {
-            0 -> return VmCodeChunk()
-            1 -> return translateGroup(repeat.children)
-            256 -> {
-                // 256 iterations can still be done with just a byte counter if you set it to zero as starting value.
-                repeat.children[0] = PtNumber(DataType.UBYTE, 0.0, repeat.count.position)
-            }
-        }
-
-        val code = VmCodeChunk()
-        val counterReg = vmRegisters.nextFree()
-        val vmDt = vmType(repeat.count.type)
-        code += expressionEval.translateExpression(repeat.count, counterReg, -1)
-        val repeatLabel = createLabelName()
-        code += VmCodeLabel(repeatLabel)
-        code += translateNode(repeat.statements)
-        code += VmCodeInstruction(Opcode.DEC, vmDt, reg1=counterReg)
-        code += VmCodeInstruction(Opcode.BNZ, vmDt, reg1=counterReg, labelSymbol = repeatLabel)
-        return code
-    }
-
-    private fun translate(jump: PtJump): VmCodeChunk {
-        val code = VmCodeChunk()
-        if(jump.address!=null)
-            throw AssemblyError("cannot jump to memory location in the vm target")
-        code += if(jump.generatedLabel!=null)
-            VmCodeInstruction(Opcode.JUMP, labelSymbol = listOf(jump.generatedLabel!!))
-        else if(jump.identifier!=null)
-            VmCodeInstruction(Opcode.JUMP, labelSymbol = jump.identifier!!.targetName)
-        else
-            throw AssemblyError("weird jump")
-        return code
-    }
-
-    private fun translateGroup(group: List<PtNode>): VmCodeChunk {
-        val code = VmCodeChunk()
-        group.forEach { code += translateNode(it) }
-        return code
-    }
-
-    private fun translate(ret: PtReturn): VmCodeChunk {
-        val code = VmCodeChunk()
-        val value = ret.value
-        if(value!=null) {
-            // Call Convention: return value is always returned in r0 (or fr0 if float)
-            code += if(value.type==DataType.FLOAT)
-                expressionEval.translateExpression(value, -1, 0)
-            else
-                expressionEval.translateExpression(value, 0, -1)
-        }
-        code += VmCodeInstruction(Opcode.RETURN)
-        return code
-    }
-
-    private fun translate(sub: PtSub): VmCodeChunk {
-        val code = VmCodeChunk()
-        code += VmCodeComment("SUB: ${sub.scopedName} -> ${sub.returntype}")
-        code += VmCodeLabel(sub.scopedName)
-        for (child in sub.children) {
-            code += translateNode(child)
-        }
-        code += VmCodeComment("SUB-END '${sub.name}'")
-        return code
-    }
-
-    private fun translate(block: PtBlock): VmCodeChunk {
-        val code = VmCodeChunk()
-        code += VmCodeComment("BLOCK '${block.name}'  addr=${block.address}  lib=${block.library}")
-        for (child in block.children) {
-            if(child !is PtAssignment) // global variable initialization is done elsewhere
-                code += translateNode(child)
-        }
-        code += VmCodeComment("BLOCK-END '${block.name}'")
-        return code
-    }
-
-
-    internal fun vmType(type: DataType): VmDataType {
-        return when(type) {
-            DataType.UBYTE,
-            DataType.BYTE -> VmDataType.BYTE
-            DataType.UWORD,
-            DataType.WORD -> VmDataType.WORD
-            DataType.FLOAT -> VmDataType.FLOAT
-            in PassByReferenceDatatypes -> VmDataType.WORD
-            else -> throw AssemblyError("no vm datatype for $type")
-        }
-    }
-
-    private var labelSequenceNumber = 0
-    internal fun createLabelName(): List<String> {
-        labelSequenceNumber++
-        return listOf("prog8_label_gen_$labelSequenceNumber")
-    }
-
-    internal fun translateBuiltinFunc(call: PtBuiltinFunctionCall, resultRegister: Int): VmCodeChunk =
-        builtinFuncGen.translate(call, resultRegister)
-
-    internal fun isZero(expression: PtExpression): Boolean = expression is PtNumber && expression.number==0.0
-
-    internal fun isOne(expression: PtExpression): Boolean = expression is PtNumber && expression.number==1.0
-}
-

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

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

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

@@ -0,0 +1,125 @@
+package prog8.codegen.virtual
+
+import prog8.code.core.AssemblyError
+import prog8.code.core.CompilationOptions
+import prog8.code.core.IAssemblyProgram
+import prog8.intermediate.*
+import prog8.vm.Syscall
+import java.io.BufferedWriter
+import kotlin.io.path.bufferedWriter
+import kotlin.io.path.div
+
+internal class VmAssemblyProgram(override val name: String, private val irProgram: IRProgram): IAssemblyProgram {
+
+    override fun assemble(dummyOptions: CompilationOptions): Boolean {
+        val outfile = irProgram.options.outputDir / ("$name.p8virt")
+        println("write code to $outfile")
+
+        // at last, allocate the variables in memory.
+        val allocations = VmVariableAllocator(irProgram.st, irProgram.encoding, irProgram.options.compTarget)
+
+        outfile.bufferedWriter().use { out ->
+            allocations.asVmMemory().forEach { (name, alloc) ->
+                out.write("var ${name} $alloc\n")
+            }
+
+            out.write("------PROGRAM------\n")
+
+            if(!irProgram.options.dontReinitGlobals) {
+                out.write("; global var inits\n")
+                irProgram.globalInits.forEach { out.writeLine(it) }
+            }
+            irProgram.blocks.firstOrNull()?.let {
+                if(it.subroutines.any { it.name=="main.start" }) {
+                    // there is a "main.start" entrypoint, jump to it
+                    out.writeLine(IRCodeInstruction(Opcode.JUMP, labelSymbol = "main.start"))
+                }
+            }
+
+            out.write("; actual program code\n")
+
+            irProgram.blocks.forEach { block ->
+                if(block.address!=null)
+                    TODO("blocks can't have a load address for vm")
+                out.write("; BLOCK ${block.name} ${block.position}\n")
+                block.inlineAssembly.forEach { asm ->
+                    out.write("; ASM ${asm.position}\n")
+                    out.write(asm.assembly)
+                    out.write("\n")
+                }
+                block.subroutines.forEach { sub ->
+                    out.write("; SUB ${sub.name} ${sub.position}\n")
+                    out.write("_${sub.name}:\n")
+                    sub.chunks.forEach { chunk ->
+                        if(chunk is IRInlineAsmChunk) {
+                            out.write("; ASM ${chunk.position}\n")
+                            out.write(processInlinedAsm(chunk.assembly, allocations))
+                            out.write("\n")
+                        } else {
+                            chunk.lines.forEach { out.writeLine(it) }
+                        }
+                    }
+                    out.write("; END SUB ${sub.name}\n")
+                }
+                block.asmSubroutines.forEach { sub ->
+                    out.write("; ASMSUB ${sub.name} ${sub.position}\n")
+                    out.write("_${sub.name}:\n")
+                    out.write(processInlinedAsm(sub.assembly, allocations))
+                    out.write("\n; END ASMSUB ${sub.name}\n")
+                }
+                out.write("; END BLOCK ${block.name}\n")
+            }
+        }
+        return true
+    }
+
+    private fun processInlinedAsm(asm: String, allocations: VmVariableAllocator): String {
+        // TODO do we have to replace variable names by their allocated address???
+        return asm
+    }
+}
+
+private fun BufferedWriter.writeLine(line: IRCodeLine) {
+    when(line) {
+        is IRCodeComment -> {
+            write("; ${line.comment}\n")
+        }
+        is IRCodeInstruction -> {
+            if(line.ins.opcode==Opcode.SYSCALL) {
+                // convert IM Syscall to VM Syscall
+                val vmSyscall = when(line.ins.value!!) {
+                    IMSyscall.SORT_UBYTE.ordinal -> Syscall.SORT_UBYTE
+                    IMSyscall.SORT_BYTE.ordinal -> Syscall.SORT_BYTE
+                    IMSyscall.SORT_UWORD.ordinal -> Syscall.SORT_UWORD
+                    IMSyscall.SORT_WORD.ordinal -> Syscall.SORT_WORD
+                    IMSyscall.ANY_BYTE.ordinal -> Syscall.ANY_BYTE
+                    IMSyscall.ANY_WORD.ordinal -> Syscall.ANY_WORD
+                    IMSyscall.ANY_FLOAT.ordinal -> Syscall.ANY_FLOAT
+                    IMSyscall.ALL_BYTE.ordinal -> Syscall.ALL_BYTE
+                    IMSyscall.ALL_WORD.ordinal -> Syscall.ALL_WORD
+                    IMSyscall.ALL_FLOAT.ordinal -> Syscall.ALL_FLOAT
+                    IMSyscall.REVERSE_BYTES.ordinal -> Syscall.REVERSE_BYTES
+                    IMSyscall.REVERSE_WORDS.ordinal -> Syscall.REVERSE_WORDS
+                    IMSyscall.REVERSE_FLOATS.ordinal -> Syscall.REVERSE_FLOATS
+                    else -> throw IllegalArgumentException("invalid IM syscall number ${line.ins.value}")
+                }
+                val newIns = line.ins.copy(value = vmSyscall.ordinal)
+                write(newIns.toString() + "\n")
+            } else
+                write(line.ins.toString() + "\n")
+        }
+        is IRCodeInlineBinary -> {
+            write("!binary ")
+            line.data.withIndex().forEach {(index, byte) ->
+                write(byte.toString(16).padStart(2,'0'))
+                if(index and 63 == 63 && index<line.data.size-1)
+                    write("\n!binary ")
+            }
+            write("\n")
+        }
+        is IRCodeLabel -> {
+            write("_${line.name}:\n")
+        }
+        else -> throw AssemblyError("invalid IR code line")
+    }
+}

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

@@ -0,0 +1,40 @@
+package prog8.codegen.virtual
+
+import prog8.code.SymbolTable
+import prog8.code.ast.PtProgram
+import prog8.code.core.CompilationOptions
+import prog8.code.core.IAssemblyGenerator
+import prog8.code.core.IAssemblyProgram
+import prog8.code.core.IErrorReporter
+import prog8.codegen.intermediate.IRCodeGen
+import prog8.intermediate.IRFileReader
+import prog8.intermediate.IRFileWriter
+import kotlin.io.path.Path
+
+class VmCodeGen(private val program: PtProgram,
+                private val symbolTable: SymbolTable,
+                private val options: CompilationOptions,
+                private val errors: IErrorReporter
+): IAssemblyGenerator {
+    override fun compileToAssembly(): IAssemblyProgram? {
+
+        val irCodeGen = IRCodeGen(program, symbolTable, options, errors)
+        val irProgram = irCodeGen.generate()
+
+        return if(options.keepIR) {
+            //create IR file on disk and read it back.
+            IRFileWriter(irProgram).writeFile()
+            val irProgram2 = IRFileReader(options.outputDir, irProgram.name).readFile()
+            VmAssemblyProgram(irProgram2.name, irProgram2)
+        } else {
+            VmAssemblyProgram(irProgram.name, irProgram)
+        }
+    }
+
+    companion object {
+        fun compileIR(listingFilename: String): IAssemblyProgram {
+            val irProgram = IRFileReader(Path(""), listingFilename).readFile()
+            return VmAssemblyProgram(irProgram.name, irProgram)
+        }
+    }
+}

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

@@ -0,0 +1,97 @@
+package prog8.codegen.virtual
+
+import prog8.code.core.*
+import prog8.intermediate.IRSymbolTable
+import prog8.intermediate.getTypeString
+
+internal class VmVariableAllocator(val st: IRSymbolTable, val encoding: IStringEncoding, memsizer: IMemSizer) {
+
+    internal val allocations = mutableMapOf<String, Int>()
+    private var freeMemoryStart: Int
+
+    val freeMem: Int
+        get() = freeMemoryStart
+
+
+    init {
+        var nextLocation = 0
+        for (variable in st.allVariables()) {
+            val memsize =
+                when (variable.dt) {
+                    DataType.STR -> variable.onetimeInitializationStringValue!!.first.length + 1  // include the zero byte
+                    in NumericDatatypes -> memsizer.memorySize(variable.dt)
+                    in ArrayDatatypes -> memsizer.memorySize(variable.dt, variable.length!!)
+                    else -> throw InternalCompilerException("weird dt")
+                }
+
+            allocations[variable.name] = nextLocation
+            nextLocation += memsize
+        }
+        for(slab in st.allMemorySlabs()) {
+            // we ignore the alignment for the VM.
+            allocations[slab.name] = nextLocation
+            nextLocation += slab.size.toInt()
+        }
+
+        freeMemoryStart = nextLocation
+    }
+
+    fun asVmMemory(): List<Pair<String, String>> {
+        val mm = mutableListOf<Pair<String, String>>()
+
+        // normal variables
+        for (variable in st.allVariables()) {
+            val location = allocations.getValue(variable.name)
+            val value = when(variable.dt) {
+                DataType.FLOAT -> (variable.onetimeInitializationNumericValue ?: 0.0).toString()
+                in NumericDatatypes -> (variable.onetimeInitializationNumericValue ?: 0).toHex()
+                DataType.STR -> {
+                    val encoded = encoding.encodeString(variable.onetimeInitializationStringValue!!.first, variable.onetimeInitializationStringValue!!.second) + listOf(0u)
+                    encoded.joinToString(",") { it.toInt().toHex() }
+                }
+                DataType.ARRAY_F -> {
+                    if(variable.onetimeInitializationArrayValue!=null) {
+                        variable.onetimeInitializationArrayValue!!.joinToString(",") { it.number!!.toString() }
+                    } else {
+                        (1..variable.length!!).joinToString(",") { "0" }
+                    }
+                }
+                in ArrayDatatypes -> {
+                    if(variable.onetimeInitializationArrayValue!==null) {
+                        variable.onetimeInitializationArrayValue!!.joinToString(",") {
+                            if(it.number!=null)
+                                it.number!!.toHex()
+                            else
+                                "&${it.addressOf!!.joinToString(".")}"
+                        }
+                    } else {
+                        (1..variable.length!!).joinToString(",") { "0" }
+                    }
+                }
+                else -> throw InternalCompilerException("weird dt")
+            }
+            mm.add(Pair(variable.name, "@$location ${getTypeString(variable)} $value"))
+        }
+
+        // memory mapped variables
+        for (variable in st.allMemMappedVariables()) {
+            val value = when(variable.dt) {
+                DataType.FLOAT -> "0.0"
+                in NumericDatatypes -> "0"
+                DataType.ARRAY_F -> (1..variable.length!!).joinToString(",") { "0.0" }
+                in ArrayDatatypes -> (1..variable.length!!).joinToString(",") { "0" }
+                else -> throw InternalCompilerException("weird dt for mem mapped var")
+            }
+            mm.add(Pair(variable.name, "@${variable.address} ${getTypeString(variable)} $value"))
+        }
+
+        // memory slabs.
+        for(slab in st.allMemorySlabs()) {
+            val address = allocations.getValue(slab.name)
+            mm.add(Pair(slab.name, "@$address ubyte[${slab.size}] 0"))
+        }
+
+        return mm
+    }
+
+}

codeOptimizers/src/prog8/optimizer/BinExprSplitter.kt

@@ -22,6 +22,9 @@ class BinExprSplitter(private val program: Program, private val options: Compila
 
     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
 

codeOptimizers/src/prog8/optimizer/ConstExprEvaluator.kt

@@ -22,9 +22,6 @@ class ConstExprEvaluator {
                 "&" -> bitwiseand(left, right)
                 "|" -> bitwiseor(left, right)
                 "^" -> bitwisexor(left, right)
-                "and" -> logicaland(left, right)
-                "or" -> logicalor(left, right)
-                "xor" -> logicalxor(left, right)
                 "<" -> NumericLiteral.fromBoolean(left < right, left.position)
                 ">" -> NumericLiteral.fromBoolean(left > right, left.position)
                 "<=" -> NumericLiteral.fromBoolean(left <= right, left.position)
@@ -58,57 +55,6 @@ class ConstExprEvaluator {
         return NumericLiteral(left.type, result.toDouble(), left.position)
     }
 
-    private fun logicalxor(left: NumericLiteral, right: NumericLiteral): NumericLiteral {
-        val error = "cannot compute $left locical-bitxor $right"
-        return when (left.type) {
-            in IntegerDatatypes -> when (right.type) {
-                in IntegerDatatypes -> NumericLiteral.fromBoolean((left.number.toInt() != 0) xor (right.number.toInt() != 0), left.position)
-                DataType.FLOAT -> NumericLiteral.fromBoolean((left.number.toInt() != 0) xor (right.number != 0.0), left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            DataType.FLOAT -> when (right.type) {
-                in IntegerDatatypes -> NumericLiteral.fromBoolean((left.number != 0.0) xor (right.number.toInt() != 0), left.position)
-                DataType.FLOAT -> NumericLiteral.fromBoolean((left.number != 0.0) xor (right.number != 0.0), left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            else -> throw ExpressionError(error, left.position)
-        }
-    }
-
-    private fun logicalor(left: NumericLiteral, right: NumericLiteral): NumericLiteral {
-        val error = "cannot compute $left locical-or $right"
-        return when (left.type) {
-            in IntegerDatatypes -> when (right.type) {
-                in IntegerDatatypes -> NumericLiteral.fromBoolean(left.number.toInt() != 0 || right.number.toInt() != 0, left.position)
-                DataType.FLOAT -> NumericLiteral.fromBoolean(left.number.toInt() != 0 || right.number != 0.0, left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            DataType.FLOAT -> when (right.type) {
-                in IntegerDatatypes -> NumericLiteral.fromBoolean(left.number != 0.0 || right.number.toInt() != 0, left.position)
-                DataType.FLOAT -> NumericLiteral.fromBoolean(left.number != 0.0 || right.number != 0.0, left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            else -> throw ExpressionError(error, left.position)
-        }
-    }
-
-    private fun logicaland(left: NumericLiteral, right: NumericLiteral): NumericLiteral {
-        val error = "cannot compute $left locical-and $right"
-        return when (left.type) {
-            in IntegerDatatypes -> when (right.type) {
-                in IntegerDatatypes -> NumericLiteral.fromBoolean(left.number.toInt() != 0 && right.number.toInt() != 0, left.position)
-                DataType.FLOAT -> NumericLiteral.fromBoolean(left.number.toInt() != 0 && right.number != 0.0, left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            DataType.FLOAT -> when (right.type) {
-                in IntegerDatatypes -> NumericLiteral.fromBoolean(left.number != 0.0 && right.number.toInt() != 0, left.position)
-                DataType.FLOAT -> NumericLiteral.fromBoolean(left.number != 0.0 && right.number != 0.0, left.position)
-                else -> throw ExpressionError(error, left.position)
-            }
-            else -> throw ExpressionError(error, left.position)
-        }
-    }
-
     private fun bitwisexor(left: NumericLiteral, right: NumericLiteral): NumericLiteral {
         if(left.type== DataType.UBYTE) {
             if(right.type in IntegerDatatypes) {

codeOptimizers/src/prog8/optimizer/ConstantFoldingOptimizer.kt

@@ -2,10 +2,10 @@ package prog8.optimizer
 
 import prog8.ast.Node
 import prog8.ast.Program
-import prog8.ast.base.ExpressionError
 import prog8.ast.base.FatalAstException
 import prog8.ast.base.UndefinedSymbolError
 import prog8.ast.expressions.*
+import prog8.ast.maySwapOperandOrder
 import prog8.ast.statements.ForLoop
 import prog8.ast.statements.VarDecl
 import prog8.ast.statements.VarDeclType
@@ -13,7 +13,6 @@ import prog8.ast.walk.AstWalker
 import prog8.ast.walk.IAstModification
 import prog8.code.core.AssociativeOperators
 import prog8.code.core.DataType
-import prog8.code.core.IntegerDatatypes
 
 
 class ConstantFoldingOptimizer(private val program: Program) : AstWalker() {
@@ -35,59 +34,8 @@ class ConstantFoldingOptimizer(private val program: Program) : AstWalker() {
     }
 
     override fun after(expr: PrefixExpression, parent: Node): Iterable<IAstModification> {
-        // Try to turn a unary prefix expression into a single constant value.
-        // Compile-time constant sub expressions will be evaluated on the spot.
-        // For instance, the expression for "- 4.5" will be optimized into the float literal -4.5
-        val subexpr = expr.expression
-        if (subexpr is NumericLiteral) {
-            // accept prefixed literal values (such as -3, not true)
-            return when (expr.operator) {
-                "+" -> listOf(IAstModification.ReplaceNode(expr, subexpr, parent))
-                "-" -> when (subexpr.type) {
-                    in IntegerDatatypes -> {
-                        listOf(IAstModification.ReplaceNode(expr,
-                                NumericLiteral.optimalInteger(-subexpr.number.toInt(), subexpr.position),
-                                parent))
-                    }
-                    DataType.FLOAT -> {
-                        listOf(IAstModification.ReplaceNode(expr,
-                                NumericLiteral(DataType.FLOAT, -subexpr.number, subexpr.position),
-                                parent))
-                    }
-                    else -> throw ExpressionError("can only take negative of int or float", subexpr.position)
-                }
-                "~" -> when (subexpr.type) {
-                    DataType.BYTE -> {
-                        listOf(IAstModification.ReplaceNode(expr,
-                                NumericLiteral(DataType.BYTE, subexpr.number.toInt().inv().toDouble(), subexpr.position),
-                                parent))
-                    }
-                    DataType.UBYTE -> {
-                        listOf(IAstModification.ReplaceNode(expr,
-                                NumericLiteral(DataType.UBYTE, (subexpr.number.toInt().inv() and 255).toDouble(), subexpr.position),
-                                parent))
-                    }
-                    DataType.WORD -> {
-                        listOf(IAstModification.ReplaceNode(expr,
-                                NumericLiteral(DataType.WORD, subexpr.number.toInt().inv().toDouble(), subexpr.position),
-                                parent))
-                    }
-                    DataType.UWORD -> {
-                        listOf(IAstModification.ReplaceNode(expr,
-                                NumericLiteral(DataType.UWORD, (subexpr.number.toInt().inv() and 65535).toDouble(), subexpr.position),
-                                parent))
-                    }
-                    else -> throw ExpressionError("can only take bitwise inversion of int", subexpr.position)
-                }
-                "not" -> {
-                    listOf(IAstModification.ReplaceNode(expr,
-                            NumericLiteral.fromBoolean(subexpr.number == 0.0, subexpr.position),
-                            parent))
-                }
-                else -> throw ExpressionError(expr.operator, subexpr.position)
-            }
-        }
-        return noModifications
+        val constValue = expr.constValue(program) ?: return noModifications
+        return listOf(IAstModification.ReplaceNode(expr, constValue, parent))
     }
 
     /*
@@ -192,6 +140,21 @@ class ConstantFoldingOptimizer(private val program: Program) : AstWalker() {
             modifications += IAstModification.ReplaceNode(expr, result, parent)
         }
 
+        if(leftconst==null && rightconst!=null && rightconst.number<0.0) {
+            if (expr.operator == "-") {
+                // X - -1 ---> X + 1
+                val posNumber = NumericLiteral.optimalNumeric(-rightconst.number, rightconst.position)
+                val plusExpr = BinaryExpression(expr.left, "+", posNumber, expr.position)
+                return listOf(IAstModification.ReplaceNode(expr, plusExpr, parent))
+            }
+            else if (expr.operator == "+") {
+                // X + -1 ---> X - 1
+                val posNumber = NumericLiteral.optimalNumeric(-rightconst.number, rightconst.position)
+                val plusExpr = BinaryExpression(expr.left, "-", posNumber, expr.position)
+                return listOf(IAstModification.ReplaceNode(expr, plusExpr, parent))
+            }
+        }
+
 
         val leftBinExpr = expr.left as? BinaryExpression
         val rightBinExpr = expr.right as? BinaryExpression
@@ -302,7 +265,6 @@ class ConstantFoldingOptimizer(private val program: Program) : AstWalker() {
     }
 
     override fun after(functionCallExpr: FunctionCallExpression, parent: Node): Iterable<IAstModification> {
-        // the args of a fuction are constfolded via recursion already.
         val constvalue = functionCallExpr.constValue(program)
         return if(constvalue!=null)
             listOf(IAstModification.ReplaceNode(functionCallExpr, constvalue, parent))
@@ -310,6 +272,14 @@ class ConstantFoldingOptimizer(private val program: Program) : AstWalker() {
             noModifications
     }
 
+    override fun after(bfc: BuiltinFunctionCall, parent: Node): Iterable<IAstModification> {
+        val constvalue = bfc.constValue(program)
+        return if(constvalue!=null)
+            listOf(IAstModification.ReplaceNode(bfc, constvalue, parent))
+        else
+            noModifications
+    }
+
     override fun after(forLoop: ForLoop, parent: Node): Iterable<IAstModification> {
         fun adjustRangeDt(rangeFrom: NumericLiteral, targetDt: DataType, rangeTo: NumericLiteral, stepLiteral: NumericLiteral?, range: RangeExpression): RangeExpression? {
             val fromCast = rangeFrom.cast(targetDt)
@@ -423,7 +393,7 @@ class ConstantFoldingOptimizer(private val program: Program) : AstWalker() {
             // both operators are the same.
 
             // If associative,  we can simply shuffle the const operands around to optimize.
-            if(expr.operator in AssociativeOperators) {
+            if(expr.operator in AssociativeOperators && maySwapOperandOrder(expr)) {
                 return if(leftIsConst) {
                     if(subleftIsConst)
                         ShuffleOperands(expr, null, subExpr, subExpr.right, null, null, expr.left)

codeOptimizers/src/prog8/optimizer/ExpressionSimplifier.kt

@@ -1,19 +1,26 @@
 package prog8.optimizer
 
-import prog8.ast.*
+import prog8.ast.IStatementContainer
+import prog8.ast.Node
+import prog8.ast.Program
 import prog8.ast.base.FatalAstException
 import prog8.ast.expressions.*
-import prog8.ast.statements.*
+import prog8.ast.maySwapOperandOrder
+import prog8.ast.statements.AnonymousScope
+import prog8.ast.statements.Assignment
+import prog8.ast.statements.IfElse
+import prog8.ast.statements.Jump
 import prog8.ast.walk.AstWalker
 import prog8.ast.walk.IAstModification
 import prog8.code.core.*
+import prog8.code.target.VMTarget
 import kotlin.math.abs
 import kotlin.math.log2
 import kotlin.math.pow
 
 // TODO add more peephole expression optimizations? Investigate what optimizations binaryen has, also see  https://egorbo.com/peephole-optimizations.html
 
-class ExpressionSimplifier(private val program: Program, private val errors: IErrorReporter) : AstWalker() {
+class ExpressionSimplifier(private val program: Program, private val compTarget: ICompilationTarget) : AstWalker() {
     private val powersOfTwo = (1..16).map { (2.0).pow(it) }.toSet()
     private val negativePowersOfTwo = powersOfTwo.map { -it }.toSet()
 
@@ -24,8 +31,9 @@ class ExpressionSimplifier(private val program: Program, private val errors: IEr
         val literal = typecast.expression as? NumericLiteral
         if (literal != null) {
             val newLiteral = literal.cast(typecast.type)
-            if (newLiteral.isValid && newLiteral.valueOrZero() !== literal)
-                mods += IAstModification.ReplaceNode(typecast.expression, newLiteral.valueOrZero(), typecast)
+            if (newLiteral.isValid && newLiteral.valueOrZero() !== literal) {
+                mods += IAstModification.ReplaceNode(typecast, newLiteral.valueOrZero(), parent)
+            }
         }
 
         // remove redundant nested typecasts
@@ -67,6 +75,22 @@ class ExpressionSimplifier(private val program: Program, private val errors: IEr
                 }
             }
         }
+
+        if(compTarget.name!=VMTarget.NAME) {
+            val booleanCondition = ifElse.condition as? BinaryExpression
+            if(booleanCondition!=null && booleanCondition.operator=="&") {
+                // special optimization of WORD & $ff00  ->  just and the msb of WORD with $ff
+                val rightNum = booleanCondition.right as? NumericLiteral
+                if(rightNum!=null && rightNum.type==DataType.UWORD && (rightNum.number.toInt() and 0x00ff)==0) {
+                    val msb = BuiltinFunctionCall(IdentifierReference(listOf("msb"), booleanCondition.left.position), mutableListOf(booleanCondition.left), booleanCondition.left.position)
+                    val bytevalue = NumericLiteral(DataType.UBYTE, (rightNum.number.toInt() shr 8).toDouble(), booleanCondition.right.position)
+                    return listOf(
+                        IAstModification.ReplaceNode(booleanCondition.left, msb, booleanCondition),
+                        IAstModification.ReplaceNode(booleanCondition.right, bytevalue, booleanCondition))
+                }
+            }
+        }
+
         return noModifications
     }
 
@@ -80,12 +104,12 @@ class ExpressionSimplifier(private val program: Program, private val errors: IEr
             throw FatalAstException("can't determine datatype of both expression operands $expr")
 
         // ConstValue <associativeoperator> X -->  X <associativeoperator> ConstValue
-        if (leftVal != null && expr.operator in AssociativeOperators && rightVal == null)
+        if (leftVal != null && expr.operator in AssociativeOperators && rightVal == null && maySwapOperandOrder(expr))
             return listOf(IAstModification.SwapOperands(expr))
 
         // NonBinaryExpression  <associativeoperator>  BinaryExpression  -->  BinaryExpression  <associativeoperator>  NonBinaryExpression
         if (expr.operator in AssociativeOperators && expr.left !is BinaryExpression && expr.right is BinaryExpression) {
-            if(parent !is Assignment || !(expr.left isSameAs parent.target))
+            if(parent !is Assignment || !(expr.left isSameAs parent.target) && maySwapOperandOrder(expr))
                 return listOf(IAstModification.SwapOperands(expr))
         }
 
@@ -187,35 +211,19 @@ class ExpressionSimplifier(private val program: Program, private val errors: IEr
             }
         }
 
+        // boolvar & 1  --> boolvar
+        // boolvar & 2  --> false
+        if(expr.operator=="&" && rightDt in IntegerDatatypes && (leftDt == DataType.BOOL || (expr.left as? TypecastExpression)?.expression?.inferType(program)?.istype(DataType.BOOL)==true)) {
+            if(rightVal?.number==1.0) {
+                return listOf(IAstModification.ReplaceNode(expr, expr.left, parent))
+            } else if(rightVal?.number!=null && (rightVal.number.toInt() and 1)==0) {
+                return listOf(IAstModification.ReplaceNode(expr, NumericLiteral.fromBoolean(false, expr.position), parent))
+            }
+        }
+
         // simplify when a term is constant and directly determines the outcome
-        val constTrue = NumericLiteral.fromBoolean(true, expr.position)
         val constFalse = NumericLiteral.fromBoolean(false, expr.position)
         val newExpr: Expression? = when (expr.operator) {
-            "or" -> {
-                when {
-                    leftVal != null && leftVal.asBooleanValue || rightVal != null && rightVal.asBooleanValue -> constTrue
-                    leftVal != null && !leftVal.asBooleanValue -> expr.right
-                    rightVal != null && !rightVal.asBooleanValue -> expr.left
-                    else -> null
-                }
-            }
-            "and" -> {
-                when {
-                    leftVal != null && !leftVal.asBooleanValue || rightVal != null && !rightVal.asBooleanValue -> constFalse
-                    leftVal != null && leftVal.asBooleanValue -> expr.right
-                    rightVal != null && rightVal.asBooleanValue -> expr.left
-                    else -> null
-                }
-            }
-            "xor" -> {
-                when {
-                    leftVal != null && !leftVal.asBooleanValue -> expr.right
-                    rightVal != null && !rightVal.asBooleanValue -> expr.left
-                    leftVal != null && leftVal.asBooleanValue -> PrefixExpression("not", expr.right, expr.right.position)
-                    rightVal != null && rightVal.asBooleanValue -> PrefixExpression("not", expr.left, expr.left.position)
-                    else -> null
-                }
-            }
             "|" -> {
                 when {
                     leftVal?.number==0.0 -> expr.right
@@ -259,6 +267,28 @@ class ExpressionSimplifier(private val program: Program, private val errors: IEr
             else -> null
         }
 
+        if(rightVal!=null && leftDt==DataType.BOOL) {
+            // see if we can replace comparison against true/1 with simpler comparison against zero
+            if (expr.operator == "==") {
+                if (rightVal.number == 1.0) {
+                    val zero = NumericLiteral(DataType.UBYTE, 0.0, expr.right.position)
+                    return listOf(
+                        IAstModification.SetExpression({expr.operator="!="}, expr, parent),
+                        IAstModification.ReplaceNode(expr.right, zero, expr)
+                    )
+                }
+            }
+            if (expr.operator == "!=") {
+                if (rightVal.number == 1.0) {
+                    val zero = NumericLiteral(DataType.UBYTE, 0.0, expr.right.position)
+                    return listOf(
+                        IAstModification.SetExpression({expr.operator="=="}, expr, parent),
+                        IAstModification.ReplaceNode(expr.right, zero, expr)
+                    )
+                }
+            }
+        }
+
         if(newExpr != null)
             return listOf(IAstModification.ReplaceNode(expr, newExpr, parent))
 
@@ -277,6 +307,12 @@ class ExpressionSimplifier(private val program: Program, private val errors: IEr
                     return listOf(IAstModification.ReplaceNode(functionCallExpr, arg.expression, parent))
                 }
             } else {
+                if(arg is IdentifierReference && arg.nameInSource.size==2
+                    && arg.nameInSource[0]=="cx16" && arg.nameInSource[1].uppercase() in RegisterOrPair.names) {
+                    // lsb(cx16.r0) -> cx16.r0L
+                    val highReg = IdentifierReference(listOf("cx16", arg.nameInSource[1]+'L'), arg.position)
+                    return listOf(IAstModification.ReplaceNode(functionCallExpr, highReg, parent))
+                }
                 val argDt = arg.inferType(program)
                 if (argDt istype DataType.BYTE || argDt istype DataType.UBYTE) {
                     // useless lsb() of byte value
@@ -298,6 +334,12 @@ class ExpressionSimplifier(private val program: Program, private val errors: IEr
                             parent))
                 }
             } else {
+                if(arg is IdentifierReference && arg.nameInSource.size==2
+                    && arg.nameInSource[0]=="cx16" && arg.nameInSource[1].uppercase() in RegisterOrPair.names) {
+                    // msb(cx16.r0) -> cx16.r0H
+                    val highReg = IdentifierReference(listOf("cx16", arg.nameInSource[1]+'H'), arg.position)
+                    return listOf(IAstModification.ReplaceNode(functionCallExpr, highReg, parent))
+                }
                 val argDt = arg.inferType(program)
                 if (argDt istype DataType.BYTE || argDt istype DataType.UBYTE) {
                     // useless msb() of byte value, replace with 0
@@ -309,49 +351,14 @@ class ExpressionSimplifier(private val program: Program, private val errors: IEr
             }
         }
 
-        return noModifications
-    }
-
-    override fun after(containment: ContainmentCheck, parent: Node): Iterable<IAstModification> {
-        val range = containment.iterable as? RangeExpression
-        if(range!=null && range.step.constValue(program)?.number==1.0) {
-            val from = range.from.constValue(program)
-            val to = range.to.constValue(program)
-            val value = containment.element
-            if(from!=null && to!=null && value.isSimple) {
-                if(to.number-from.number>6.0) {
-                    // replace containment test with X>=from and X<=to
-                    val left = BinaryExpression(value, ">=", from, containment.position)
-                    val right = BinaryExpression(value.copy(), "<=", to, containment.position)
-                    val comparison = BinaryExpression(left, "and", right, containment.position)
-                    return listOf(IAstModification.ReplaceNode(containment, comparison, parent))
-                }
+        if(functionCallExpr.target.nameInSource == listOf("mkword")) {
+            if(functionCallExpr.args[0].constValue(program)?.number==0.0) {
+                // just cast the lsb to uword
+                val cast = TypecastExpression(functionCallExpr.args[1], DataType.UWORD, true, functionCallExpr.position)
+                return listOf(IAstModification.ReplaceNode(functionCallExpr, cast, parent))
             }
         }
-        return noModifications
-    }
 
-    override fun after(pipeExpr: PipeExpression, parent: Node) = processPipe(pipeExpr, parent)
-    override fun after(pipe: Pipe, parent: Node) = processPipe(pipe, parent)
-
-    private fun processPipe(pipe: IPipe, parent: Node): Iterable<IAstModification> {
-        if(pipe.source.isSimple) {
-            val segments = pipe.segments
-            if(segments.size==1) {
-                // replace the whole pipe with a normal function call
-                val funcname = (segments[0] as IFunctionCall).target
-                val call = if(pipe is Pipe)
-                    FunctionCallStatement(funcname, mutableListOf(pipe.source), true, pipe.position)
-                else
-                    FunctionCallExpression(funcname, mutableListOf(pipe.source), pipe.position)
-                return listOf(IAstModification.ReplaceNode(pipe as Node, call, parent))
-            } else if(segments.size>1) {
-                // replace source+firstsegment by firstsegment(source) call as the new source
-                val firstSegment = segments.removeAt(0) as IFunctionCall
-                val call = FunctionCallExpression(firstSegment.target, mutableListOf(pipe.source), pipe.position)
-                return listOf(IAstModification.ReplaceNode(pipe.source, call, pipe as Node))
-            }
-        }
         return noModifications
     }
 
@@ -487,19 +494,14 @@ class ExpressionSimplifier(private val program: Program, private val errors: IEr
                     }
                 }
                 in powersOfTwo -> {
-                    if (leftDt in IntegerDatatypes) {
-                        // divided by a power of two => shift right
+                    if (leftDt==DataType.UBYTE || leftDt==DataType.UWORD) {
+                        // Unsigned number divided by a power of two => shift right
+                        // Signed number can't simply be bitshifted in this case (due to rounding issues for negative values),
+                        // so we leave that as is and let the code generator deal with it.
                         val numshifts = log2(cv).toInt()
                         return BinaryExpression(expr.left, ">>", NumericLiteral.optimalInteger(numshifts, expr.position), expr.position)
                     }
                 }
-                in negativePowersOfTwo -> {
-                    if (leftDt in IntegerDatatypes) {
-                        // divided by a negative power of two => negate, then shift right
-                        val numshifts = log2(-cv).toInt()
-                        return BinaryExpression(PrefixExpression("-", expr.left, expr.position), ">>", NumericLiteral.optimalInteger(numshifts, expr.position), expr.position)
-                    }
-                }
             }
 
             if (leftDt == DataType.UBYTE) {
@@ -557,9 +559,10 @@ class ExpressionSimplifier(private val program: Program, private val errors: IEr
                 }
                 in negativePowersOfTwo -> {
                     if (leftValue.inferType(program).isInteger) {
-                        // times a negative power of two => negate, then shift left
+                        // times a negative power of two => negate, then shift
                         val numshifts = log2(-cv).toInt()
-                        return BinaryExpression(PrefixExpression("-", expr2.left, expr.position), "<<", NumericLiteral.optimalInteger(numshifts, expr.position), expr.position)
+                        val negation = PrefixExpression("-", expr2.left, expr.position)
+                        return BinaryExpression(negation, "<<", NumericLiteral.optimalInteger(numshifts, expr.position), expr.position)
                     }
                 }
             }
@@ -589,7 +592,14 @@ class ExpressionSimplifier(private val program: Program, private val errors: IEr
             DataType.UWORD, DataType.WORD -> {
                 if (amount >= 16) {
                     return NumericLiteral(targetDt, 0.0, expr.position)
-                } else if (amount > 8) {
+                }
+                else if(amount==8) {
+                    // shift left by 8 bits is just a byte operation: mkword(lsb(X), 0)
+                    val lsb = FunctionCallExpression(IdentifierReference(listOf("lsb"), expr.position), mutableListOf(expr.left), expr.position)
+                    return FunctionCallExpression(IdentifierReference(listOf("mkword"), expr.position), mutableListOf(lsb, NumericLiteral(DataType.UBYTE, 0.0, expr.position)), expr.position)
+                }
+                else if (amount > 8) {
+                    // same as above but with residual shifts.
                     val lsb = FunctionCallExpression(IdentifierReference(listOf("lsb"), expr.position), mutableListOf(expr.left), expr.position)
                     val shifted = BinaryExpression(lsb, "<<", NumericLiteral.optimalInteger(amount - 8, expr.position), expr.position)
                     return FunctionCallExpression(IdentifierReference(listOf("mkword"), expr.position), mutableListOf(shifted, NumericLiteral.optimalInteger(0, expr.position)), expr.position)
@@ -628,12 +638,19 @@ class ExpressionSimplifier(private val program: Program, private val errors: IEr
                 if (amount >= 16) {
                     return NumericLiteral.optimalInteger(0, expr.position)
                 }
+                else if(amount==8) {
+                    // shift right by 8 bits is just a byte operation: msb(X) as uword
+                    val msb = FunctionCallExpression(IdentifierReference(listOf("msb"), expr.position), mutableListOf(expr.left), expr.position)
+                    return TypecastExpression(msb, DataType.UWORD, true, expr.position)
+                }
                 else if (amount > 8) {
+                    // same as above but with residual shifts.
                     val msb = FunctionCallExpression(IdentifierReference(listOf("msb"), expr.position), mutableListOf(expr.left), expr.position)
                     return TypecastExpression(BinaryExpression(msb, ">>", NumericLiteral.optimalInteger(amount - 8, expr.position), expr.position), DataType.UWORD, true, expr.position)
                 }
             }
             DataType.WORD -> {
+                // bit-shifting a signed value shouldn't be allowed by the compiler but here we go...
                 if (amount > 16) {
                     expr.right = NumericLiteral.optimalInteger(16, expr.right.position)
                     return null
@@ -646,7 +663,7 @@ class ExpressionSimplifier(private val program: Program, private val errors: IEr
     }
 
     private fun reorderAssociativeWithConstant(expr: BinaryExpression, leftVal: NumericLiteral?): BinExprWithConstants {
-        if (expr.operator in AssociativeOperators && leftVal != null) {
+        if (expr.operator in AssociativeOperators && leftVal != null && maySwapOperandOrder(expr)) {
             // swap left and right so that right is always the constant
             val tmp = expr.left
             expr.left = expr.right

codeOptimizers/src/prog8/optimizer/Extensions.kt

@@ -60,8 +60,8 @@ fun Program.inlineSubroutines(): Int {
     return inliner.applyModifications()
 }
 
-fun Program.simplifyExpressions(errors: IErrorReporter) : Int {
-    val opti = ExpressionSimplifier(this, errors)
+fun Program.simplifyExpressions(target: ICompilationTarget) : Int {
+    val opti = ExpressionSimplifier(this, target)
     opti.visit(this)
     return opti.applyModifications()
 }

codeOptimizers/src/prog8/optimizer/Inliner.kt

@@ -14,6 +14,8 @@ import prog8.code.core.InternalCompilerException
 private  fun isEmptyReturn(stmt: Statement): Boolean = stmt is Return && stmt.value==null
 
 
+// inliner potentially enables *ONE LINED* subroutines, wihtout to be inlined.
+
 class Inliner(val program: Program): AstWalker() {
 
     class DetermineInlineSubs(val program: Program): IAstVisitor {
@@ -104,7 +106,7 @@ class Inliner(val program: Program): AstWalker() {
                                     } else
                                         false
                                 }
-                                is Jump, is GoSub -> true
+                                is Jump -> true
                                 else -> false
                             }
                     }
@@ -142,8 +144,10 @@ class Inliner(val program: Program): AstWalker() {
         }
 
         private fun makeFullyScoped(call: FunctionCallExpression) {
+            val sub = call.target.targetSubroutine(program)!!
+            val scopedName = IdentifierReference(sub.scopedName, call.target.position)
             val scopedArgs = makeScopedArgs(call.args)
-            val scopedCall = FunctionCallExpression(call.target.copy(), scopedArgs.toMutableList(), call.position)
+            val scopedCall = FunctionCallExpression(scopedName, scopedArgs.toMutableList(), call.position)
             modifications += IAstModification.ReplaceNode(call, scopedCall, call.parent)
         }
 
@@ -166,43 +170,63 @@ class Inliner(val program: Program): AstWalker() {
         return super.before(program)
     }
 
-    override fun after(gosub: GoSub, parent: Node): Iterable<IAstModification> {
-        val sub = gosub.identifier.targetStatement(program) as? Subroutine
-        if(sub!=null && sub.inline && sub.parameters.isEmpty()) {
+    private fun possibleInlineFcallStmt(sub: Subroutine, origNode: Node, parent: Node): Iterable<IAstModification> {
+        if(sub.inline && sub.parameters.isEmpty()) {
             require(sub.statements.size == 1 || (sub.statements.size == 2 && isEmptyReturn(sub.statements[1])))
             return if(sub.isAsmSubroutine) {
                 // simply insert the asm for the argument-less routine
-                listOf(IAstModification.ReplaceNode(gosub, sub.statements.single().copy(), parent))
+                listOf(IAstModification.ReplaceNode(origNode, sub.statements.single().copy(), parent))
             } else {
                 // note that we don't have to process any args, because we online inline parameterless subroutines.
                 when (val toInline = sub.statements.first()) {
-                    is Return -> noModifications
-                    else -> listOf(IAstModification.ReplaceNode(gosub, toInline.copy(), parent))
+                    is Return -> {
+                        val fcall = toInline.value as? FunctionCallExpression
+                        if(fcall!=null) {
+                            // insert the function call expression as a void function call directly
+                            val call = FunctionCallStatement(fcall.target.copy(), fcall.args.map { it.copy() }.toMutableList(), true, fcall.position)
+                            listOf(IAstModification.ReplaceNode(origNode, call, parent))
+                        } else
+                            noModifications
+                    }
+                    else -> listOf(IAstModification.ReplaceNode(origNode, toInline.copy(), parent))
                 }
             }
-
         }
         return noModifications
     }
 
     override fun after(functionCallStatement: FunctionCallStatement, parent: Node): Iterable<IAstModification>  {
         val sub = functionCallStatement.target.targetStatement(program) as? Subroutine
+        return if(sub==null)
+            noModifications
+        else
+            possibleInlineFcallStmt(sub, functionCallStatement, parent)
+    }
+
+    override fun before(functionCallExpr: FunctionCallExpression, parent: Node): Iterable<IAstModification> {
+        val sub = functionCallExpr.target.targetStatement(program) as? Subroutine
         if(sub!=null && sub.inline && sub.parameters.isEmpty()) {
             require(sub.statements.size==1 || (sub.statements.size==2 && isEmptyReturn(sub.statements[1])))
             return if(sub.isAsmSubroutine) {
-                // simply insert the asm for the argument-less routine
-                listOf(IAstModification.ReplaceNode(functionCallStatement, sub.statements.single().copy(), parent))
+                // cannot inline assembly directly in the Ast here as an Asm node is not an expression....
+                noModifications
             } else {
-                // note that we don't have to process any args, because we online inline parameterless subroutines.
                 when (val toInline = sub.statements.first()) {
-                    is Return -> noModifications
-                    else -> listOf(IAstModification.ReplaceNode(functionCallStatement, toInline.copy(), parent))
+                    is Return -> {
+                        // is an expression, so we have to have a Return here in the inlined sub
+                        // note that we don't have to process any args, because we online inline parameterless subroutines.
+                        if(toInline.value!=null)
+                            listOf(IAstModification.ReplaceNode(functionCallExpr, toInline.value!!.copy(), parent))
+                        else
+                            noModifications
+                    }
+                    else -> noModifications
                 }
             }
         }
+
         return noModifications
     }
 
-    // TODO also inline function call expressions, and remove it from the StatementOptimizer
 }
 

codeOptimizers/src/prog8/optimizer/StatementOptimizer.kt

@@ -16,46 +16,6 @@ class StatementOptimizer(private val program: Program,
                          private val compTarget: ICompilationTarget
 ) : AstWalker() {
 
-    override fun before(functionCallExpr: FunctionCallExpression, parent: Node): Iterable<IAstModification> {
-        // if the first instruction in the called subroutine is a return statement with a simple value (NOT being a parameter),
-        // remove the jump altogeter and inline the returnvalue directly. (only if not part of a pipe expression)
-
-        fun scopePrefix(variable: IdentifierReference): IdentifierReference {
-            val target = variable.targetStatement(program) as INamedStatement
-            return IdentifierReference(target.scopedName, variable.position)
-        }
-
-        val subroutine = functionCallExpr.target.targetSubroutine(program)
-        if(subroutine!=null) {
-            val first = subroutine.statements.asSequence().filterNot { it is VarDecl || it is Directive }.firstOrNull()
-            if(first is Return && first.value?.isSimple==true && parent !is IPipe) {
-                val copy = when(val orig = first.value!!) {
-                    is AddressOf -> {
-                        val scoped = scopePrefix(orig.identifier)
-                        AddressOf(scoped, orig.position)
-                    }
-                    is DirectMemoryRead -> {
-                        when(val expr = orig.addressExpression) {
-                            is NumericLiteral -> DirectMemoryRead(expr.copy(), orig.position)
-                            else -> return noModifications
-                        }
-                    }
-                    is IdentifierReference -> {
-                        if(orig.targetVarDecl(program)?.origin == VarDeclOrigin.SUBROUTINEPARAM)
-                            return noModifications
-                        else
-                            scopePrefix(orig)
-                    }
-                    is NumericLiteral -> orig.copy()
-                    is StringLiteral -> orig.copy()
-                    else -> return noModifications
-                }
-                return listOf(IAstModification.ReplaceNode(functionCallExpr, copy, parent))
-            }
-        }
-        return noModifications
-    }
-
     override fun after(functionCallStatement: FunctionCallStatement, parent: Node): Iterable<IAstModification> {
         if(functionCallStatement.target.nameInSource.size==1) {
             val functionName = functionCallStatement.target.nameInSource[0]
@@ -113,31 +73,6 @@ class StatementOptimizer(private val program: Program,
             }
         }
 
-        // if the first instruction in the called subroutine is a return statement, remove the jump altogeter
-        val subroutine = functionCallStatement.target.targetSubroutine(program)
-        if(subroutine!=null) {
-            val first = subroutine.statements.asSequence().filterNot { it is VarDecl || it is Directive }.firstOrNull()
-            if(first is Return)
-                return listOf(IAstModification.Remove(functionCallStatement, parent as IStatementContainer))
-        }
-
-        if(compTarget.name!=VMTarget.NAME) {
-            // see if we can optimize any complex argument expressions to be just a simple variable
-            // TODO for now, only works for single-argument functions because we use just 1 temp var: R9
-            if(functionCallStatement.target.nameInSource !in listOf(listOf("pop"), listOf("popw")) && functionCallStatement.args.size==1) {
-                val arg = functionCallStatement.args[0]
-                if(!arg.isSimple && arg !is IFunctionCall) {
-                    val name = getTempRegisterName(arg.inferType(program))
-                    val tempvar = IdentifierReference(name, functionCallStatement.position)
-                    val assignTempvar = Assignment(AssignTarget(tempvar.copy(), null, null, functionCallStatement.position), arg, AssignmentOrigin.OPTIMIZER, functionCallStatement.position)
-                    return listOf(
-                        IAstModification.InsertBefore(functionCallStatement, assignTempvar, parent as IStatementContainer),
-                        IAstModification.ReplaceNode(arg, tempvar, functionCallStatement)
-                    )
-                }
-            }
-        }
-
         return noModifications
     }
 
@@ -148,7 +83,7 @@ class StatementOptimizer(private val program: Program,
 
         // empty true part? switch with the else part
         if(ifElse.truepart.isEmpty() && ifElse.elsepart.isNotEmpty()) {
-            val invertedCondition = PrefixExpression("not", ifElse.condition, ifElse.condition.position)
+            val invertedCondition = BinaryExpression(ifElse.condition, "==", NumericLiteral(DataType.UBYTE, 0.0, ifElse.condition.position), ifElse.condition.position)
             val emptyscope = AnonymousScope(mutableListOf(), ifElse.elsepart.position)
             val truepart = AnonymousScope(ifElse.elsepart.statements, ifElse.truepart.position)
             return listOf(
@@ -284,25 +219,6 @@ class StatementOptimizer(private val program: Program,
         return noModifications
     }
 
-
-    // NOTE: do NOT remove a jump to the next statement, because this will lead to wrong code when this occurs at the end of a subroutine
-    // if we want to optimize this away, it can be done later at code generation time.
-
-    override fun after(gosub: GoSub, parent: Node): Iterable<IAstModification> {
-        // if the next statement is return with no returnvalue, change into a regular jump if there are no parameters as well.
-        val subroutineParams = gosub.identifier.targetSubroutine(program)?.parameters
-        if(subroutineParams!=null && subroutineParams.isEmpty()) {
-            val returnstmt = gosub.nextSibling() as? Return
-            if(returnstmt!=null && returnstmt.value==null) {
-                return listOf(
-                    IAstModification.Remove(returnstmt, parent as IStatementContainer),
-                    IAstModification.ReplaceNode(gosub, Jump(null, gosub.identifier, null, gosub.position), parent)
-                )
-            }
-        }
-        return noModifications
-    }
-
     override fun before(assignment: Assignment, parent: Node): Iterable<IAstModification> {
 
         val binExpr = assignment.value as? BinaryExpression
@@ -313,7 +229,7 @@ class StatementOptimizer(private val program: Program,
                     val op1 = binExpr.operator
                     val op2 = rExpr.operator
 
-                    if(rExpr.left is NumericLiteral && op2 in AssociativeOperators) {
+                    if(rExpr.left is NumericLiteral && op2 in AssociativeOperators && maySwapOperandOrder(binExpr)) {
                         // associative operator, make sure the constant numeric value is second (right)
                         return listOf(IAstModification.SwapOperands(rExpr))
                     }
@@ -352,7 +268,7 @@ class StatementOptimizer(private val program: Program,
             if(binExpr.operator in AssociativeOperators && binExpr.right isSameAs assignment.target) {
                 // associative operator, swap the operands so that the assignment target is first (left)
                 // unless the other operand is the same in which case we don't swap (endless loop!)
-                if (!(binExpr.left isSameAs binExpr.right))
+                if (!(binExpr.left isSameAs binExpr.right) && maySwapOperandOrder(binExpr))
                     return listOf(IAstModification.SwapOperands(binExpr))
             }
 
@@ -469,31 +385,22 @@ class StatementOptimizer(private val program: Program,
         if(compTarget.name==VMTarget.NAME)
             return noModifications
 
-        fun returnViaIntermediaryVar(value: Expression): Iterable<IAstModification>? {
-            val subr = returnStmt.definingSubroutine!!
-            val returnDt = subr.returntypes.single()
-            if (returnDt in IntegerDatatypes) {
-                // first assign to intermediary variable, then return that
-                val (returnVarName, _) = program.getTempVar(returnDt)
-                val returnValueIntermediary = IdentifierReference(returnVarName, returnStmt.position)
-                val tgt = AssignTarget(returnValueIntermediary, null, null, returnStmt.position)
-                val assign = Assignment(tgt, value, AssignmentOrigin.OPTIMIZER, returnStmt.position)
-                val returnReplacement = Return(returnValueIntermediary.copy(), returnStmt.position)
-                return listOf(
-                    IAstModification.InsertBefore(returnStmt, assign, parent as IStatementContainer),
-                    IAstModification.ReplaceNode(returnStmt, returnReplacement, parent)
-                )
-            }
-            return null
-        }
-
-        // TODO decision when to use intermediary variable to calculate returnvalue seems a bit arbitrary...
         val returnvalue = returnStmt.value
         if (returnvalue!=null) {
-            if (returnvalue is BinaryExpression || (returnvalue is TypecastExpression && !returnvalue.expression.isSimple)) {
-                val mod = returnViaIntermediaryVar(returnvalue)
-                if(mod!=null)
-                    return mod
+            val dt = returnvalue.inferType(program).getOr(DataType.UNDEFINED)
+            if(dt!=DataType.UNDEFINED) {
+                if (returnvalue is BinaryExpression || (returnvalue is TypecastExpression && !returnvalue.expression.isSimple)) {
+                    // first assign to intermediary variable, then return that
+                    val (returnVarName, _) = program.getTempVar(dt)
+                    val returnValueIntermediary = IdentifierReference(returnVarName, returnStmt.position)
+                    val tgt = AssignTarget(returnValueIntermediary, null, null, returnStmt.position)
+                    val assign = Assignment(tgt, returnvalue, AssignmentOrigin.OPTIMIZER, returnStmt.position)
+                    val returnReplacement = Return(returnValueIntermediary.copy(), returnStmt.position)
+                    return listOf(
+                        IAstModification.InsertBefore(returnStmt, assign, parent as IStatementContainer),
+                        IAstModification.ReplaceNode(returnStmt, returnReplacement, parent)
+                    )
+                }
             }
         }
 

codeOptimizers/src/prog8/optimizer/UnusedCodeRemover.kt

@@ -1,7 +1,10 @@
 package prog8.optimizer
 
 import prog8.ast.*
-import prog8.ast.expressions.*
+import prog8.ast.expressions.BinaryExpression
+import prog8.ast.expressions.NumericLiteral
+import prog8.ast.expressions.PrefixExpression
+import prog8.ast.expressions.TypecastExpression
 import prog8.ast.statements.*
 import prog8.ast.walk.AstWalker
 import prog8.ast.walk.IAstModification
@@ -28,23 +31,23 @@ class UnusedCodeRemover(private val program: Program,
 
     override fun before(breakStmt: Break, parent: Node): Iterable<IAstModification> {
         reportUnreachable(breakStmt)
-        return emptyList()
+        return noModifications
     }
 
     override fun before(jump: Jump, parent: Node): Iterable<IAstModification> {
         reportUnreachable(jump)
-        return emptyList()
+        return noModifications
     }
 
     override fun before(returnStmt: Return, parent: Node): Iterable<IAstModification> {
         reportUnreachable(returnStmt)
-        return emptyList()
+        return noModifications
     }
 
     override fun before(functionCallStatement: FunctionCallStatement, parent: Node): Iterable<IAstModification> {
         if(functionCallStatement.target.nameInSource.last() == "exit")
             reportUnreachable(functionCallStatement)
-        return emptyList()
+        return noModifications
     }
 
     private fun reportUnreachable(stmt: Statement) {
@@ -236,7 +239,6 @@ class UnusedCodeRemover(private val program: Program,
                                 is PrefixExpression,
                                 is BinaryExpression,
                                 is TypecastExpression,
-                                is PipeExpression,
                                 is IFunctionCall -> { /* don't remove */ }
                                 else -> {
                                     if(assign1.value !is IFunctionCall)

compiler/build.gradle

@@ -27,20 +27,20 @@ compileTestKotlin {
 def prog8version = rootProject.file('compiler/res/version.txt').text.trim()
 
 dependencies {
-    implementation project(':codeAst')
     implementation project(':codeCore')
     implementation project(':codeOptimizers')
     implementation project(':compilerAst')
     implementation project(':codeGenCpu6502')
     implementation project(':codeGenVirtual')
     implementation project(':codeGenExperimental')
+    implementation project(':virtualmachine')
     implementation 'org.antlr:antlr4-runtime:4.10.1'
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
     // implementation "org.jetbrains.kotlin:kotlin-reflect"
     implementation 'org.jetbrains.kotlinx:kotlinx-cli:0.3.4'
-    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.14"
+    implementation "com.michael-bull.kotlin-result:kotlin-result-jvm:1.1.16"
 
-    testImplementation 'io.kotest:kotest-runner-junit5-jvm:5.1.0'
+    testImplementation 'io.kotest:kotest-runner-junit5-jvm:5.3.2'
 }
 
 configurations.all {
@@ -68,7 +68,6 @@ sourceSets {
     test {
         java {
             srcDir "${project.projectDir}/test"
-            srcDir "${project(':compilerAst').projectDir}/test/helpers"
         }
     }
 }

compiler/compiler.iml

@@ -17,11 +17,11 @@
     <orderEntry type="library" name="io.kotest.runner.junit5.jvm" level="project" />
     <orderEntry type="library" name="antlr.antlr4" level="project" />
     <orderEntry type="module" module-name="codeCore" />
-    <orderEntry type="module" module-name="codeAst" />
     <orderEntry type="module" module-name="compilerAst" />
     <orderEntry type="module" module-name="codeOptimizers" />
     <orderEntry type="module" module-name="codeGenCpu6502" />
     <orderEntry type="module" module-name="codeGenExperimental" />
     <orderEntry type="module" module-name="codeGenVirtual" />
+    <orderEntry type="module" module-name="virtualmachine" />
   </component>
 </module>

compiler/res/prog8lib/atari/syslib.p8

@@ -1,8 +1,5 @@
 ; Prog8 definitions for the Atari800XL
 ; Including memory registers, I/O registers, Basic and Kernal subroutines.
-;
-; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
-;
 
 atari {
 

compiler/res/prog8lib/atari/textio.p8

@@ -1,6 +1,4 @@
 ; Prog8 definitions for the Text I/O and Screen routines for the Atari 800XL
-;
-; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
 
 %import syslib
 %import conv

compiler/res/prog8lib/c128/floats.p8

@@ -1,6 +1,4 @@
 ; Prog8 definitions for floating point handling on the Commodore 128
-;
-; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
 
 %option enable_floats
 %import floats_functions

compiler/res/prog8lib/c128/syslib.p8

@@ -1,8 +1,5 @@
 ; Prog8 definitions for the Commodore-128
 ; Including memory registers, I/O registers, Basic and Kernal subroutines.
-;
-; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
-;
 
 c64 {
 
@@ -725,6 +722,7 @@ cx16 {
     ; $1300-$1bff is unused RAM on C128. We'll use $1a00-$1bff as the lo/hi evalstack.
     ; the virtual registers are allocated at the bottom of the eval-stack (should be ample space unless
     ; you're doing insane nesting of expressions...)
+    ; NOTE: the memory location of these registers can change based on the "-esa" compiler option
     &uword r0  = $1b00
     &uword r1  = $1b02
     &uword r2  = $1b04

compiler/res/prog8lib/c128/textio.p8

@@ -1,8 +1,4 @@
 ; Prog8 definitions for the Text I/O and Screen routines for the Commodore-64
-;
-; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
-;
-; indent format: TABS, size=8
 
 %import syslib
 %import conv

compiler/res/prog8lib/c64/floats.p8

@@ -1,8 +1,4 @@
 ; Prog8 definitions for floating point handling on the Commodore-64
-;
-; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
-;
-; indent format: TABS, size=8
 
 %option enable_floats
 %import floats_functions
@@ -13,7 +9,6 @@ floats {
         const float  PI     = 3.141592653589793
         const float  TWOPI  = 6.283185307179586
 
-        float  tempvar_swap_float     ; used for some swap() operations
 
 ; ---- C64 basic and kernal ROM float constants and functions ----
 

compiler/res/prog8lib/c64/graphics.p8

@@ -38,8 +38,12 @@ graphics {
 
         if y1>y2 {
             ; make sure dy is always positive to have only 4 instead of 8 special cases
-            swap(x1, x2)
-            swap(y1, y2)
+            cx16.r0 = x1
+            x1 = x2
+            x2 = cx16.r0
+            cx16.r0L = y1
+            y1 = y2
+            y2 = cx16.r0L
         }
         word @zp dx = (x2 as word)-x1
         word @zp dy = (y2 as word)-y1
@@ -311,7 +315,7 @@ hline_zero2
     ; for efficiency of internal algorithms here is the internal plot routine
     ; that takes the plotx coordinate in a separate variable instead of the XY register pair:
 
-    uword internal_plotx     ; 0..319        ; separate 'parameter' for internal_plot()
+    uword @zp internal_plotx     ; 0..319        ; separate 'parameter' for internal_plot()
 
     asmsub  internal_plot(ubyte ploty @A) clobbers (A, X, Y) {      ; internal_plotx is 16 bits 0 to 319... doesn't fit in a register
         %asm {{

compiler/res/prog8lib/c64/syslib.p8

@@ -1,9 +1,5 @@
 ; Prog8 definitions for the Commodore-64
 ; Including memory registers, I/O registers, Basic and Kernal subroutines.
-;
-; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
-;
-; indent format: TABS, size=8
 
 c64 {
         &ubyte  TIME_HI         = $a0       ; software jiffy clock, hi byte
@@ -689,6 +685,7 @@ cx16 {
     ; (because there's no room for them in the zeropage)
     ; they are allocated at the bottom of the eval-stack (should be ample space unless
     ; you're doing insane nesting of expressions...)
+    ; NOTE: the memory location of these registers can change based on the "-esa" compiler option
     &uword r0  = $cf00
     &uword r1  = $cf02
     &uword r2  = $cf04

compiler/res/prog8lib/c64/textio.p8

@@ -1,8 +1,4 @@
 ; Prog8 definitions for the Text I/O and Screen routines for the Commodore-64
-;
-; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
-;
-; indent format: TABS, size=8
 
 %import syslib
 %import conv

compiler/res/prog8lib/conv.p8

@@ -1,7 +1,4 @@
 ; Number conversions routines.
-;
-; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
-
 
 conv {
 
@@ -419,6 +416,9 @@ _loop
 	beq  _stop
 	cmp  #7                 ; screencode letters A-F are 1-6
 	bcc  _add_letter
+	and  #127
+	cmp  #97
+	bcs  _try_iso            ; maybe letter is iso:'a'-iso:'f' (97-102)
 	cmp  #'g'
 	bcs  _stop
 	cmp  #'a'
@@ -454,6 +454,11 @@ _add_letter
 	sta  P8ZP_SCRATCH_B1
 	pla
 	jmp  _calc
+_try_iso
+        cmp  #103
+        bcs  _stop
+        and  #63
+        bne  _add_letter
 	}}
 }
 

compiler/res/prog8lib/cx16/cx16diskio.p8

@@ -1,6 +1,4 @@
 ; Cx16 specific disk drive I/O routines.
-;
-; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
 
 %import diskio
 
@@ -73,4 +71,102 @@ cx16diskio {
         }}
     }
 
+
+    ; replacement function that makes use of fast block read capability of the X16
+    ; use this in place of regular diskio.f_read()
+    sub f_read(uword bufferpointer, uword num_bytes) -> uword {
+        ; -- read from the currently open file, up to the given number of bytes.
+        ;    returns the actual number of bytes read.  (checks for End-of-file and error conditions)
+        if not diskio.iteration_in_progress or not num_bytes
+            return 0
+
+        diskio.list_blocks = 0     ; we reuse this variable for the total number of bytes read
+        if diskio.have_first_byte {
+            diskio.have_first_byte=false
+            @(bufferpointer) = diskio.first_byte
+            bufferpointer++
+            diskio.list_blocks++
+            num_bytes--
+        }
+
+        void c64.CHKIN(11)        ; use #11 as input channel again
+
+        ; commander X16 supports fast block-read via macptr() kernal call
+        uword size
+        while num_bytes {
+            size = 255
+            if num_bytes<size
+                size = num_bytes
+            size = cx16.macptr(lsb(size), bufferpointer)
+            if_cs
+                goto byte_read_loop     ; macptr block read not supported, do fallback loop
+            diskio.list_blocks += size
+            bufferpointer += size
+            if msb(bufferpointer) == $c0
+                bufferpointer = mkword($a0, lsb(bufferpointer))  ; wrap over bank boundary
+            num_bytes -= size
+            if c64.READST() & $40 {
+                diskio.f_close()       ; end of file, close it
+                break
+            }
+        }
+        return diskio.list_blocks  ; number of bytes read
+
+byte_read_loop:         ; fallback if macptr() isn't supported on the device
+        %asm {{
+            lda  bufferpointer
+            sta  m_in_buffer+1
+            lda  bufferpointer+1
+            sta  m_in_buffer+2
+        }}
+        repeat num_bytes {
+            %asm {{
+                jsr  c64.CHRIN
+                sta  cx16.r5
+m_in_buffer     sta  $ffff
+                inc  m_in_buffer+1
+                bne  +
+                inc  m_in_buffer+2
++               inc  diskio.list_blocks
+                bne  +
+                inc  diskio.list_blocks+1
++
+            }}
+
+            if cx16.r5==$0d {   ; chance on I/o error status?
+                diskio.first_byte = c64.READST()
+                if diskio.first_byte & $40 {
+                    diskio.f_close()       ; end of file, close it
+                    diskio.list_blocks--   ; don't count that last CHRIN read
+                }
+                if diskio.first_byte
+                    return diskio.list_blocks  ; number of bytes read
+            }
+        }
+        return diskio.list_blocks  ; number of bytes read
+    }
+
+    ; replacement function that makes use of fast block read capability of the X16
+    ; use this in place of regular diskio.f_read_all()
+    sub f_read_all(uword bufferpointer) -> uword {
+        ; -- read the full contents of the file, returns number of bytes read.
+        if not diskio.iteration_in_progress
+            return 0
+
+        uword total_read = 0
+        if diskio.have_first_byte {
+            diskio.have_first_byte=false
+            @(bufferpointer) = diskio.first_byte
+            bufferpointer++
+            total_read = 1
+        }
+
+        while not c64.READST() {
+            uword size = cx16diskio.f_read(bufferpointer, 256)
+            total_read += size
+            bufferpointer += size
+        }
+        return total_read
+    }
+
 }

compiler/res/prog8lib/cx16/floats.p8

@@ -1,8 +1,4 @@
 ; Prog8 definitions for floating point handling on the CommanderX16
-;
-; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
-;
-; indent format: TABS, size=8
 
 %option enable_floats
 %import floats_functions

compiler/res/prog8lib/cx16/gfx2.p8

@@ -28,7 +28,7 @@ gfx2 {
     uword width = 0
     uword height = 0
     ubyte bpp = 0
-    ubyte monochrome_dont_stipple_flag = false            ; set to false to enable stippling mode in monochrome displaymodes
+    bool monochrome_dont_stipple_flag = false            ; set to false to enable stippling mode in monochrome displaymodes
 
     sub screen_mode(ubyte mode) {
         when mode {
@@ -127,7 +127,7 @@ gfx2 {
         position(0, 0)
     }
 
-    sub monochrome_stipple(ubyte enable) {
+    sub monochrome_stipple(bool enable) {
         monochrome_dont_stipple_flag = not enable
     }
 
@@ -394,8 +394,12 @@ _done
         ; This code special-cases various quadrant loops to allow simple ++ and -- operations.
         if y1>y2 {
             ; make sure dy is always positive to have only 4 instead of 8 special cases
-            swap(x1, x2)
-            swap(y1, y2)
+            cx16.r0 = x1
+            x1 = x2
+            x2 = cx16.r0
+            cx16.r0 = y1
+            y1 = y2
+            y2 = cx16.r0
         }
         word @zp dx = (x2 as word)-x1
         word @zp dy = (y2 as word)-y1
@@ -679,7 +683,7 @@ _done
         }
     }
 
-    sub position2(uword @zp x, uword y, ubyte also_port_1) {
+    sub position2(uword @zp x, uword y, bool also_port_1) {
         position(x, y)
         if also_port_1 {
             when active_mode {
@@ -840,25 +844,28 @@ _done
             }
             6 -> {
                 ; hires 4c
+                ; we're going to use a few cx16 registers to make sure every variable is in zeropage in the inner loop.
+                cx16.r11L = color
+                cx16.r8 = y
                 while @(sctextptr) {
                     chardataptr = charset_addr + (@(sctextptr) as uword)*8
                     repeat 8 {
                         ; TODO rewrite this inner loop partly in assembly
                         ;      requires expanding the charbits to 2-bits per pixel (based on color)
                         ;      also it's way more efficient to draw whole horizontal spans instead of per-character
-                        ubyte charbits = cx16.vpeek(charset_bank, chardataptr)
+                        cx16.r9L = cx16.vpeek(charset_bank, chardataptr)  ; get the 8 horizontal character bits
+                        cx16.r7 = x
                         repeat 8 {
-                            charbits <<= 1
+                            cx16.r9L <<= 1
                             if_cs
-                                plot(x, y, color)
-                            x++
+                                plot(cx16.r7, cx16.r8, cx16.r11L)
+                            cx16.r7++
                         }
-                        x-=8
                         chardataptr++
-                        y++
+                        cx16.r8++
                     }
                     x+=8
-                    y-=8
+                    cx16.r8-=8
                     sctextptr++
                 }
             }

compiler/res/prog8lib/cx16/graphics.p8

@@ -2,15 +2,20 @@
 %import textio
 
 ; Bitmap pixel graphics module for the CommanderX16
-; wraps the graphics functions that are in ROM.
-; only black/white monochrome 320x200 for now. (i.e. truncated at the bottom)
-; For full-screen 640x480 or 320x240 graphics, use the "gfx2" module instead. (but that is Cx16-specific)
+; Wraps the graphics functions that are in ROM.
+; Only lo-res 320x240 256 color mode for now.
+; Unlike graphics module on the C64, you can use colors() to set new drawing colors for every draw operation.
+; For other resolutions or other color modes, use the "gfx2" module instead. (which is Cx16-specific)
 ; Note: there is no color palette manipulation here, you have to do that yourself or use the "palette" module.
 
 
 graphics {
     const uword WIDTH = 320
-    const ubyte HEIGHT = 200
+    const ubyte HEIGHT = 240
+
+
+    ubyte stroke_color = 1
+    ubyte background_color = 0
 
     sub enable_bitmap_mode() {
         ; enable bitmap screen, erase it and set colors to black/white.
@@ -27,10 +32,18 @@ graphics {
 
 
     sub clear_screen(ubyte pixelcolor, ubyte bgcolor) {
+        stroke_color = pixelcolor
+        background_color = bgcolor
         cx16.GRAPH_set_colors(pixelcolor, pixelcolor, bgcolor)
         cx16.GRAPH_clear()
     }
 
+    sub colors(ubyte stroke, ubyte fill) {
+        ; this routine is only available on the cx16, other targets can't change colors on the fly
+        cx16.GRAPH_set_colors(stroke, fill, background_color)
+        stroke_color = stroke
+    }
+
     sub line(uword @zp x1, ubyte @zp y1, uword @zp x2, ubyte @zp y2) {
         cx16.GRAPH_draw_line(x1, y1, x2, y2)
     }
@@ -71,31 +84,31 @@ graphics {
             cx16.r0 = xcenter + xx
             cx16.r1 = ycenter + yy
             cx16.FB_cursor_position2()
-            cx16.FB_set_pixel(1)
+            cx16.FB_set_pixel(stroke_color)
             cx16.r0 = xcenter - xx
             cx16.FB_cursor_position2()
-            cx16.FB_set_pixel(1)
+            cx16.FB_set_pixel(stroke_color)
             cx16.r0 = xcenter + xx
             cx16.r1 = ycenter - yy
             cx16.FB_cursor_position2()
-            cx16.FB_set_pixel(1)
+            cx16.FB_set_pixel(stroke_color)
             cx16.r0 = xcenter - xx
             cx16.FB_cursor_position2()
-            cx16.FB_set_pixel(1)
+            cx16.FB_set_pixel(stroke_color)
             cx16.r0 = xcenter + yy
             cx16.r1 = ycenter + xx
             cx16.FB_cursor_position2()
-            cx16.FB_set_pixel(1)
+            cx16.FB_set_pixel(stroke_color)
             cx16.r0 = xcenter - yy
             cx16.FB_cursor_position2()
-            cx16.FB_set_pixel(1)
+            cx16.FB_set_pixel(stroke_color)
             cx16.r0 = xcenter + yy
             cx16.r1 = ycenter - xx
             cx16.FB_cursor_position2()
-            cx16.FB_set_pixel(1)
+            cx16.FB_set_pixel(stroke_color)
             cx16.r0 = xcenter - yy
             cx16.FB_cursor_position2()
-            cx16.FB_set_pixel(1)
+            cx16.FB_set_pixel(stroke_color)
             yy++
             if decisionOver2<=0 {
                 decisionOver2 += (yy as word)*2+1

compiler/res/prog8lib/cx16/palette.p8

@@ -13,20 +13,20 @@ palette {
         cx16.vpoke(1, vera_palette_ptr, msb(color))
     }
 
-    sub set_rgb4(uword palette_bytes_ptr, uword num_colors) {
-        ; 2 bytes per color entry, the Vera uses this, but the R/GB bytes order is swapped
+    sub set_rgb_be(uword palette_ptr, uword num_colors) {
+        ; 1 word per color entry, $0rgb in big endian format
         vera_palette_ptr = $fa00
         repeat num_colors {
-            cx16.vpoke(1, vera_palette_ptr+1, @(palette_bytes_ptr))
-            palette_bytes_ptr++
-            cx16.vpoke(1, vera_palette_ptr, @(palette_bytes_ptr))
-            palette_bytes_ptr++
+            cx16.vpoke(1, vera_palette_ptr+1, @(palette_ptr))
+            palette_ptr++
+            cx16.vpoke(1, vera_palette_ptr, @(palette_ptr))
+            palette_ptr++
             vera_palette_ptr+=2
         }
     }
 
     sub set_rgb(uword palette_words_ptr, uword num_colors) {
-        ; 1 word per color entry (in little endian format so $gb0r)
+        ; 1 word per color entry (in little endian format as layed out in video memory, so $gb0r)
         vera_palette_ptr = $fa00
         repeat num_colors*2 {
             cx16.vpoke(1, vera_palette_ptr, @(palette_words_ptr))

compiler/res/prog8lib/cx16/psg.p8

@@ -0,0 +1,176 @@
+%import syslib
+
+psg {
+    ; $1F9C0 - $1F9FF 	16 blocks of 4 PSG registers (16 voices)
+    ; 00  frequency word LSB
+    ; 01  frequency word MSB.    freqword = HERZ / 0.3725290298461914
+    ; 02  bit 7 =right, bit 6 = left, bits 5-0 = volume 0-63 levels
+    ; 03  bit 7,6 = waveform, bits 5-0 = Pulse width 0-63
+    ; waveform: 0=pulse, 1=sawtooth, 2=triangle, 3=noise
+    const ubyte PULSE    = %00000000
+    const ubyte SAWTOOTH = %01000000
+    const ubyte TRIANGLE = %10000000
+    const ubyte NOISE    = %11000000
+    const ubyte LEFT     = %01000000
+    const ubyte RIGHT    = %10000000
+
+    sub voice(ubyte voice_num, ubyte channel, ubyte volume, ubyte waveform, ubyte pulsewidth) {
+        ; -- Enables a 'voice' on the PSG.
+        ;    voice_num = 0-15, the voice number.
+        ;    channel = either LEFT or RIGHT or (LEFT|RIGHT). Specifies the stereo channel(s) to use.
+        ;    volume = 0-63, the starting volume for the voice
+        ;    waveform = one of PULSE,SAWTOOTH,TRIANGLE,NOISE.
+        ;    pulsewidth = 0-63.  Specifies the pulse width for waveform=PULSE.
+        envelope_states[voice_num] = 255
+        cx16.r0 = $f9c2 + voice_num * 4
+        cx16.VERA_CTRL = 0
+        cx16.VERA_ADDR_L = lsb(cx16.r0)
+        cx16.VERA_ADDR_M = msb(cx16.r0)
+        cx16.VERA_ADDR_H = 1
+        cx16.VERA_DATA0 = channel | volume
+        cx16.VERA_ADDR_L++
+        cx16.VERA_DATA0 = waveform | pulsewidth
+        envelope_volumes[voice_num] = mkword(volume, 0)
+        envelope_maxvolumes[voice_num] = volume
+    }
+
+;    sub freq_hz(ubyte voice_num, float hertz) {
+;        ; this would rely on floating point math to convert hertz to vera frequency
+;        ; could be replaced by integer math maybe with a lookup table?
+;        uword vera_freq = (hertz / 0.3725290298461914) as uword
+;        freq(voice_num, vera_freq)
+;    }
+
+    sub freq(ubyte voice_num, uword vera_freq) {
+        ; -- Changes the frequency of the voice's sound.
+        ;    voice_num = 0-15,  vera_freq = 0-65535  calculate this via the formula given in the Vera's PSG documentation.
+        ;    (https://github.com/commanderx16/x16-docs/blob/master/VERA%20Programmer's%20Reference.md)
+        cx16.r0 = $f9c0 + voice_num * 4
+        cx16.VERA_CTRL = 0
+        cx16.VERA_ADDR_L = lsb(cx16.r0)
+        cx16.VERA_ADDR_M = msb(cx16.r0)
+        cx16.VERA_ADDR_H = 1
+        cx16.VERA_DATA0 = lsb(vera_freq)
+        cx16.VERA_ADDR_L++
+        cx16.VERA_DATA0 = msb(vera_freq)
+    }
+
+    sub volume(ubyte voice_num, ubyte vol) {
+        ; -- Modifies the volume of this voice.
+        ;    voice_num = 0-15, vol = 0-63 where 0=silent, 63=loudest.
+        cx16.r0 = $f9c2 + voice_num * 4
+        cx16.vpoke(1, cx16.r0, cx16.vpeek(1, cx16.r0) & %11000000 | vol)
+        envelope_volumes[voice_num] = mkword(vol, 0)
+        envelope_maxvolumes[voice_num] = vol
+    }
+
+    sub pulse_width(ubyte voice_num, ubyte pw) {
+        ; -- Modifies the pulse width of this voice (when waveform=PULSE)
+        ;    voice_num = 0-15, pw = 0-63  where 0=narrow, 63=50%cycle so square wave.
+        cx16.r0 = $f9c3 + voice_num * 4
+        cx16.vpoke(1, cx16.r0, cx16.vpeek(1, cx16.r0) & %11000000 | pw)
+    }
+
+    sub envelope(ubyte voice_num, ubyte maxvolume, ubyte attack, ubyte sustain, ubyte release) {
+        ; -- Enables AttackSustainRelease volume envelope for a voice.
+        ;    Note: this requires setting up envelopes_irq() as well, read its description.
+        ;    voice_num = 0-15   maxvolume = 0-63
+        ;    attack, sustain, release = 0-255 that determine the speed of the A/D/R.
+        ;    TODO describe how the speeds are calculated. For now, experiment. Higher values means *slower* enveloping.
+        envelope_states[voice_num] = 255
+        envelope_attacks[voice_num] = attack
+        envelope_sustains[voice_num] = sustain
+        envelope_releases[voice_num] = release
+        if attack
+            attack = 0
+        else
+            attack = maxvolume     ; max volume when no attack is set
+        envelope_volumes[voice_num] = mkword(attack, 0)
+        envelope_maxvolumes[voice_num] = maxvolume
+        envelope_states[voice_num] = 0
+    }
+
+    sub silent() {
+        ; -- Shut down all PSG voices.
+        for cx16.r1L in 0 to 15 {
+            envelope_states[cx16.r1L] = 255
+            envelope_volumes[cx16.r1L] = 0
+            volume(cx16.r1L, 0)
+        }
+    }
+
+    sub envelopes_irq() {
+        ; If you want to use real-time volume envelopes (Attack-Sustain-Release),
+        ; you have to call this routine every 1/60th second, for example from your vsync irq handler,
+        ; or just install this routine as the only irq handler if you don't have to do other things there.
+        ; Example: cx16.set_irq(&psg.envelopes_irq, true)
+
+        ; cx16.r0 = the volume word (volume scaled by 256)
+        ; cx16.r1L = the voice number
+        ; cx16.r2L = attack value
+
+        pushw(cx16.r0)
+        push(cx16.r1L)
+        push(cx16.r2L)
+        pushw(cx16.r9)
+        ; calculate new volumes
+        for cx16.r1L in 0 to 15 {
+            when envelope_states[cx16.r1L] {
+                0 -> {
+                    ; attack
+                    cx16.r2L = envelope_maxvolumes[cx16.r1L]
+                    cx16.r0 = envelope_volumes[cx16.r1L] + envelope_attacks[cx16.r1L] * $0040
+                    if msb(cx16.r0) > cx16.r2L or envelope_attacks[cx16.r1L]==0 {
+                        cx16.r0 = mkword(cx16.r2L, 0)
+                        envelope_attacks[cx16.r1L] = 0
+                        envelope_states[cx16.r1L] = 1  ; start sustain
+                    }
+                    envelope_volumes[cx16.r1L] = cx16.r0
+                }
+                1 -> {
+                    ; sustain
+                    if envelope_sustains[cx16.r1L] {
+                        envelope_sustains[cx16.r1L]--
+                    } else {
+                        envelope_states[cx16.r1L] = 2  ; start release
+                    }
+                }
+                2 -> {
+                    ; release
+                    cx16.r0 = envelope_volumes[cx16.r1L] - envelope_releases[cx16.r1L] * $0040
+                    if msb(cx16.r0) & %11000000 {
+                        cx16.r0 = 0
+                        envelope_releases[cx16.r1L] = 0
+                    }
+                    envelope_volumes[cx16.r1L] = cx16.r0
+                }
+            }
+        }
+
+        ; set new volumes of all 16 voices, using vera stride of 4
+        cx16.push_vera_context()
+        cx16.VERA_CTRL = 0
+        cx16.VERA_ADDR_L = $c2
+        cx16.VERA_ADDR_M = $f9
+        cx16.VERA_ADDR_H = 1 | %00110000
+        cx16.VERA_CTRL = 1
+        cx16.VERA_ADDR_L = $c2
+        cx16.VERA_ADDR_M = $f9
+        cx16.VERA_ADDR_H = 1 | %00110000
+        for cx16.r1L in 0 to 15 {
+            cx16.VERA_DATA0 = cx16.VERA_DATA1 & %11000000 | msb(envelope_volumes[cx16.r1L])
+        }
+        cx16.pop_vera_context()
+        popw(cx16.r9)
+        pop(cx16.r2L)
+        pop(cx16.r1L)
+        popw(cx16.r0)
+    }
+
+    ubyte[16] envelope_states
+    uword[16] envelope_volumes      ; scaled by 256
+    ubyte[16] envelope_attacks
+    ubyte[16] envelope_sustains
+    ubyte[16] envelope_releases
+    ubyte[16] envelope_maxvolumes
+}

compiler/res/prog8lib/cx16/syslib.p8

@@ -1,9 +1,5 @@
 ; Prog8 definitions for the CommanderX16
 ; Including memory registers, I/O registers, Basic and Kernal subroutines.
-;
-; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
-;
-; indent format: TABS, size=8
 
 c64 {
 
@@ -102,7 +98,7 @@ cx16 {
     &uword  ISTOP           = $0328
     &uword  IGETIN          = $032a
     &uword  ICLALL          = $032c
-    &uword  KEYHDL          = $032e     ; keyboard scan code handler
+    &uword  KEYHDL          = $032e     ; keyboard scan code handler see examples/cx16/keyboardhandler.p8
     &uword  ILOAD           = $0330
     &uword  ISAVE           = $0332
     &uword  NMI_VEC         = $FFFA     ; 65c02 nmi vector, determined by the kernal if banked in
@@ -310,7 +306,7 @@ romsub $ff5c = lkupsa(ubyte sa @Y)  clobbers(A,X,Y)
 romsub $ff5f = screen_mode(ubyte mode @A, ubyte getCurrent @Pc)  clobbers(A, X, Y) -> ubyte @Pc
 romsub $ff62 = screen_set_charset(ubyte charset @A, uword charsetptr @XY)  clobbers(A,X,Y)      ; incompatible with C128  dlchr()
 ; not yet supported: romsub $ff65 = pfkey()  clobbers(A,X,Y)
-romsub $ff6e = jsrfar()
+romsub $ff6e = jsrfar()  ; following word = address to call, byte after that=rom/ram bank it is in
 romsub $ff74 = fetch(ubyte bank @X, ubyte index @Y)  clobbers(X) -> ubyte @A
 romsub $ff77 = stash(ubyte data @A, ubyte bank @X, ubyte index @Y)  clobbers(X)
 romsub $ff7a = cmpare(ubyte data @A, ubyte bank @X, ubyte index @Y)  clobbers(X)
@@ -367,12 +363,13 @@ romsub $fed5 = console_set_paging_message(uword msgptr @R0)  clobbers(A,X,Y)
 romsub $fecf = entropy_get() -> ubyte @A, ubyte @X, ubyte @Y
 romsub $fecc = monitor()  clobbers(A,X,Y)
 
-romsub $ff44 = macptr()  clobbers(A,X,Y)
+romsub $ff44 = macptr(ubyte length @A, uword buffer @XY)  clobbers(A) -> ubyte @Pc, uword @XY
 romsub $ff47 = enter_basic(ubyte cold_or_warm @Pc)  clobbers(A,X,Y)
 romsub $ff4d = clock_set_date_time(uword yearmonth @R0, uword dayhours @R1, uword minsecs @R2, ubyte jiffies @R3)  clobbers(A, X, Y)
 romsub $ff50 = clock_get_date_time()  clobbers(A, X, Y)  -> uword @R0, uword @R1, uword @R2, ubyte @R3   ; result registers see clock_set_date_time()
 
 ; keyboard, mouse, joystick
+; note: also see the kbdbuf_clear() helper routine below!
 romsub $febd = kbdbuf_peek() -> ubyte @A, ubyte @X     ; key in A, queue length in X
 romsub $febd = kbdbuf_peek2() -> uword @AX             ; alternative to above to not have the hassle to deal with multiple return values
 romsub $fec0 = kbdbuf_get_modifiers() -> ubyte @A
@@ -384,6 +381,15 @@ romsub $ff53 = joystick_scan()  clobbers(A, X, Y)
 romsub $ff56 = joystick_get(ubyte joynr @A) -> ubyte @A, ubyte @X, ubyte @Y
 romsub $ff56 = joystick_get2(ubyte joynr @A) clobbers(Y) -> uword @AX   ; alternative to above to not have the hassle to deal with multiple return values
 
+asmsub kbdbuf_clear() {
+    ; -- convenience helper routine to clear the keyboard buffer
+    %asm {{
+-       jsr  c64.GETIN
+        bne  -
+        rts
+    }}
+}
+
 asmsub mouse_config2(ubyte shape @A) clobbers (A, X, Y) {
     ; -- convenience wrapper function that handles the screen resolution for mouse_config() for you
     %asm {{
@@ -415,28 +421,28 @@ asmsub mouse_pos() -> ubyte @A {
 inline asmsub rombank(ubyte bank @A) {
     ; -- set the rom banks
     %asm {{
-        sta  $01            ; rom bank register (v39+, used to be cx16.d1prb $9f60 in v38)
+        sta  $01
     }}
 }
 
 inline asmsub rambank(ubyte bank @A) {
     ; -- set the ram bank
     %asm {{
-        sta  $00            ; ram bank register (v39+, used to be cx16.d1pra $9f61 in v38)
+        sta  $00
     }}
 }
 
 inline asmsub getrombank() -> ubyte @A {
     ; -- get the current rom bank
     %asm {{
-        lda  $01            ; rom bank register (v39+, used to be cx16.d1prb $9f60 in v38)
+        lda  $01
     }}
 }
 
 inline asmsub getrambank() -> ubyte @A {
     ; -- get the current ram bank
     %asm {{
-        lda  $00            ; ram bank register (v39+, used to be cx16.d1pra $9f61 in v38)
+        lda  $00
     }}
 }
 
@@ -643,8 +649,12 @@ asmsub  init_system_phase2()  {
 
 asmsub  cleanup_at_exit() {
     ; executed when the main subroutine does rts
-    ; just an rts here, nothing special to clean up on cx16
     %asm {{
+        lda  #1
+        sta  $00        ; ram bank 1
+        lda  #4
+        sta  $01        ; rom bank 4 (kernal)
+        stz  $2d        ; hack to reset machine code monitor bank to 0
         rts
     }}
 }
@@ -735,6 +745,56 @@ IRQ_SCRATCH_ZPWORD2	.word  0
 		}}
 }
 
+asmsub push_vera_context() clobbers(A) {
+    ; -- use this at the start of your IRQ handler if it uses Vera registers, to save the state
+    %asm {{
+        ; note cannot store this on cpu hardware stack because this gets called as a subroutine
+        lda  cx16.VERA_ADDR_L
+        sta  _vera_storage
+        lda  cx16.VERA_ADDR_M
+        sta  _vera_storage+1
+        lda  cx16.VERA_ADDR_H
+        sta  _vera_storage+2
+        lda  cx16.VERA_CTRL
+        sta  _vera_storage+3
+        eor  #1
+        sta  cx16.VERA_CTRL
+        lda  cx16.VERA_ADDR_L
+        sta  _vera_storage+4
+        lda  cx16.VERA_ADDR_M
+        sta  _vera_storage+5
+        lda  cx16.VERA_ADDR_H
+        sta  _vera_storage+6
+        lda  cx16.VERA_CTRL
+        sta  _vera_storage+7
+        rts
+_vera_storage:  .byte 0,0,0,0,0,0,0,0
+    }}
+}
+
+asmsub pop_vera_context() clobbers(A) {
+    ; -- use this at the end of your IRQ handler if it uses Vera registers, to restore the state
+    %asm {{
+        lda  cx16.push_vera_context._vera_storage+7
+        sta  cx16.VERA_CTRL
+        lda  cx16.push_vera_context._vera_storage+6
+        sta  cx16.VERA_ADDR_H
+        lda  cx16.push_vera_context._vera_storage+5
+        sta  cx16.VERA_ADDR_M
+        lda  cx16.push_vera_context._vera_storage+4
+        sta  cx16.VERA_ADDR_L
+        lda  cx16.push_vera_context._vera_storage+3
+        sta  cx16.VERA_CTRL
+        lda  cx16.push_vera_context._vera_storage+2
+        sta  cx16.VERA_ADDR_H
+        lda  cx16.push_vera_context._vera_storage+1
+        sta  cx16.VERA_ADDR_M
+        lda  cx16.push_vera_context._vera_storage+0
+        sta  cx16.VERA_ADDR_L
+        rts
+    }}
+}
+
 
 asmsub  restore_irq() clobbers(A) {
 	%asm {{
@@ -818,7 +878,9 @@ sys {
         ; Soft-reset the system back to initial power-on Basic prompt.
         %asm {{
             sei
-            stz  $01            ; bank the kernal in
+            stz  $01                        ; bank the kernal in
+            lda  #$80
+            sta  cx16.VERA_CTRL             ; reset Vera (kernal doesn't do this?)
             jmp  (cx16.RESET_VEC)
         }}
     }

compiler/res/prog8lib/cx16/textio.p8

@@ -1,8 +1,4 @@
 ; Prog8 definitions for the Text I/O and Screen routines for the CommanderX16
-;
-; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
-;
-; indent format: TABS, size=8
 
 %import syslib
 %import conv

compiler/res/prog8lib/diskio.p8

@@ -1,6 +1,4 @@
 ; C64 and Cx16 disk drive I/O routines.
-;
-; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
 
 %import textio
 %import string
@@ -8,11 +6,12 @@
 
 diskio {
 
-    sub directory(ubyte drivenumber) -> ubyte {
+    sub directory(ubyte drivenumber) -> bool {
         ; -- Prints the directory contents of disk drive 8-11 to the screen. Returns success.
 
         c64.SETNAM(1, "$")
         c64.SETLFS(13, drivenumber, 0)
+        ubyte status = 1
         void c64.OPEN()          ; open 13,8,0,"$"
         if_cs
             goto io_error
@@ -25,8 +24,13 @@ diskio {
         }
 
         ; while not key pressed / EOF encountered, read data.
-        ubyte status = c64.READST()
-        while not status {
+        status = c64.READST()
+        if status!=0 {
+            status = 1
+            goto io_error
+        }
+
+        while status==0 {
             ubyte low = c64.CHRIN()
             ubyte high = c64.CHRIN()
             txt.print_uw(mkword(high, low))
@@ -45,9 +49,9 @@ diskio {
             if c64.STOP2()
                 break
         }
+        status = c64.READST()
 
 io_error:
-        status = c64.READST()
         c64.CLRCHN()        ; restore default i/o devices
         c64.CLOSE(13)
 
@@ -61,34 +65,69 @@ io_error:
         return true
     }
 
+    sub diskname(ubyte drivenumber) -> uword {
+        ; -- Returns pointer to disk name string or 0 if failure.
+
+        c64.SETNAM(1, "$")
+        c64.SETLFS(13, drivenumber, 0)
+        ubyte okay = false
+        void c64.OPEN()          ; open 13,8,0,"$"
+        if_cs
+            goto io_error
+        void c64.CHKIN(13)        ; use #13 as input channel
+        if_cs
+            goto io_error
+
+        repeat 6 {
+            void c64.CHRIN()     ; skip the 6 prologue bytes
+        }
+        if c64.READST()!=0
+            goto io_error
+
+        ; while not key pressed / EOF encountered, read data.
+        cx16.r0 = &list_filename
+        repeat {
+            @(cx16.r0) = c64.CHRIN()
+            if @(cx16.r0)==0
+                break
+            cx16.r0++
+        }
+        okay = true
+
+io_error:
+        c64.CLRCHN()        ; restore default i/o devices
+        c64.CLOSE(13)
+        if okay
+            return &list_filename
+        return 0
+    }
 
     ; internal variables for the iterative file lister / loader
-    ubyte list_skip_disk_name
+    bool list_skip_disk_name
     uword list_pattern
     uword list_blocks
-    ubyte iteration_in_progress = false
+    bool iteration_in_progress = false
     ubyte @zp first_byte
-    ubyte have_first_byte
-    str   list_filename = "?" * 32
-
+    bool have_first_byte
+    str list_filename = "?" * 50
 
     ; ----- get a list of files (uses iteration functions internally) -----
 
     sub list_files(ubyte drivenumber, uword pattern_ptr, uword name_ptrs, ubyte max_names) -> ubyte {
-        ; -- fill the array 'name_ptrs' with (pointers to) the names of the files requested.
-        const uword names_buf_size = 800
-        uword names_buffer = memory("filenames", names_buf_size, 0)
-        uword buffer_start = names_buffer
+        ; -- fill the array 'name_ptrs' with (pointers to) the names of the files requested. Returns number of files.
+        const uword filenames_buf_size = 800
+        uword filenames_buffer = memory("filenames", filenames_buf_size, 0)
+        uword buffer_start = filenames_buffer
         ubyte files_found = 0
         if lf_start_list(drivenumber, pattern_ptr) {
             while lf_next_entry() {
-                @(name_ptrs) = lsb(names_buffer)
+                @(name_ptrs) = lsb(filenames_buffer)
                 name_ptrs++
-                @(name_ptrs) = msb(names_buffer)
+                @(name_ptrs) = msb(filenames_buffer)
                 name_ptrs++
-                names_buffer += string.copy(diskio.list_filename, names_buffer) + 1
+                filenames_buffer += string.copy(diskio.list_filename, filenames_buffer) + 1
                 files_found++
-                if names_buffer - buffer_start > names_buf_size-18
+                if filenames_buffer - buffer_start > filenames_buf_size-18
                     break
                 if files_found == max_names
                     break
@@ -100,7 +139,7 @@ io_error:
 
     ; ----- iterative file lister functions (uses io channel 12) -----
 
-    sub lf_start_list(ubyte drivenumber, uword pattern_ptr) -> ubyte {
+    sub lf_start_list(ubyte drivenumber, uword pattern_ptr) -> bool {
         ; -- start an iterative file listing with optional pattern matching.
         ;    note: only a single iteration loop can be active at a time!
         lf_end_list()
@@ -129,7 +168,7 @@ io_error:
         return false
     }
 
-    sub lf_next_entry() -> ubyte {
+    sub lf_next_entry() -> bool {
         ; -- retrieve the next entry from an iterative file listing session.
         ;    results will be found in list_blocks and list_filename.
         ;    if it returns false though, there are no more entries (or an error occurred).
@@ -201,7 +240,7 @@ close_end:
 
     ; ----- iterative file loader functions (uses io channel 11) -----
 
-    sub f_open(ubyte drivenumber, uword filenameptr) -> ubyte {
+    sub f_open(ubyte drivenumber, uword filenameptr) -> bool {
         ; -- open a file for iterative reading with f_read
         ;    note: only a single iteration loop can be active at a time!
         f_close()
@@ -210,14 +249,16 @@ close_end:
         c64.SETLFS(11, drivenumber, 0)
         void c64.OPEN()          ; open 11,8,0,"filename"
         if_cc {
-            iteration_in_progress = true
-            have_first_byte = false
-            void c64.CHKIN(11)        ; use #11 as input channel
-            if_cc {
-                first_byte = c64.CHRIN()   ; read first byte to test for file not found
-                if not c64.READST() {
-                    have_first_byte = true
-                    return true
+            if c64.READST()==0 {
+                iteration_in_progress = true
+                have_first_byte = false
+                void c64.CHKIN(11)        ; use #11 as input channel
+                if_cc {
+                    first_byte = c64.CHRIN()   ; read first byte to test for file not found
+                    if not c64.READST() {
+                        have_first_byte = true
+                        return true
+                    }
                 }
             }
         }
@@ -228,6 +269,8 @@ close_end:
     sub f_read(uword bufferpointer, uword num_bytes) -> uword {
         ; -- read from the currently open file, up to the given number of bytes.
         ;    returns the actual number of bytes read.  (checks for End-of-file and error conditions)
+        ;    NOTE: on systems with banked ram (such as Commander X16) this routine DOES NOT
+        ;          automatically load into subsequent banks if it reaches a bank boundary!
         if not iteration_in_progress or not num_bytes
             return 0
 
@@ -241,6 +284,7 @@ close_end:
         }
 
         void c64.CHKIN(11)        ; use #11 as input channel again
+
         %asm {{
             lda  bufferpointer
             sta  m_in_buffer+1
@@ -263,13 +307,15 @@ m_in_buffer     sta  $ffff
 
             if cx16.r5==$0d {   ; chance on I/o error status?
                 first_byte = c64.READST()
-                if first_byte & $40
+                if first_byte & $40 {
                     f_close()       ; end of file, close it
+                    list_blocks--   ; don't count that last CHRIN read
+                }
                 if first_byte
-                    return list_blocks
+                    return list_blocks  ; number of bytes read
             }
         }
-        return list_blocks
+        return list_blocks  ; number of bytes read
     }
 
     sub f_read_all(uword bufferpointer) -> uword {
@@ -277,19 +323,20 @@ m_in_buffer     sta  $ffff
         if not iteration_in_progress
             return 0
 
-        list_blocks = 0     ; we reuse this variable for the total number of bytes read
+        uword total_read = 0
         if have_first_byte {
             have_first_byte=false
             @(bufferpointer) = first_byte
             bufferpointer++
-            list_blocks++
+            total_read = 1
         }
 
         while not c64.READST() {
-            list_blocks += f_read(bufferpointer, 256)
-            bufferpointer += 256
+            uword size = f_read(bufferpointer, 256)
+            total_read += size
+            bufferpointer += size
         }
-        return list_blocks
+        return total_read
     }
 
     asmsub f_readline(uword bufptr @AY) clobbers(X) -> ubyte @Y {
@@ -339,7 +386,7 @@ _end        rts
 
     ; ----- iterative file saver functions (uses io channel 14) -----
 
-    sub f_open_w(ubyte drivenumber, uword filenameptr) -> ubyte {
+    sub f_open_w(ubyte drivenumber, uword filenameptr) -> bool {
         ; -- open a file for iterative writing with f_write
         f_close_w()
 
@@ -354,7 +401,7 @@ _end        rts
         return false
     }
 
-    sub f_write(uword bufferpointer, uword num_bytes) -> ubyte {
+    sub f_write(uword bufferpointer, uword num_bytes) -> bool {
         ; -- write the given umber of bytes to the currently open file
         if num_bytes!=0 {
             void c64.CHKOUT(14)        ; use #14 as input channel again
@@ -378,8 +425,8 @@ _end        rts
 
     sub status(ubyte drivenumber) -> uword {
         ; -- retrieve the disk drive's current status message
-        uword messageptr = &filename
-        c64.SETNAM(0, filename)
+        uword messageptr = &list_filename
+        c64.SETNAM(0, list_filename)
         c64.SETLFS(15, drivenumber, 15)
         void c64.OPEN()          ; open 15,8,15
         if_cs
@@ -389,22 +436,25 @@ _end        rts
             goto io_error
 
         while not c64.READST() {
-            @(messageptr) = c64.CHRIN()
+            first_byte = c64.CHRIN()
+            if first_byte=='\r' or first_byte=='\n'
+                break
+            @(messageptr) = first_byte
             messageptr++
         }
-
         @(messageptr) = 0
+
 done:
         c64.CLRCHN()        ; restore default i/o devices
         c64.CLOSE(15)
-        return filename
+        return list_filename
 
 io_error:
-        filename = "?disk error"
+        list_filename = "?disk error"
         goto done
     }
 
-    sub save(ubyte drivenumber, uword filenameptr, uword address, uword size) -> ubyte {
+    sub save(ubyte drivenumber, uword filenameptr, uword address, uword size) -> bool {
         c64.SETNAM(string.length(filenameptr), filenameptr)
         c64.SETLFS(1, drivenumber, 0)
         uword @shared end_address = address + size
@@ -474,7 +524,7 @@ io_error:
 
     ; Internal routine, only to be used on Commander X16 platform if headerless=true,
     ; because this routine uses kernal support for that to load headerless files.
-    sub load_headerless_cx16(ubyte drivenumber, uword filenameptr, uword address_override, ubyte headerless) -> uword {
+    sub load_headerless_cx16(ubyte drivenumber, uword filenameptr, uword address_override, bool headerless) -> uword {
         c64.SETNAM(string.length(filenameptr), filenameptr)
         ubyte secondary = 1
         cx16.r1 = 0
@@ -502,10 +552,10 @@ io_error:
 
     sub delete(ubyte drivenumber, uword filenameptr) {
         ; -- delete a file on the drive
-        filename[0] = 's'
-        filename[1] = ':'
-        ubyte flen = string.copy(filenameptr, &filename+2)
-        c64.SETNAM(flen+2, filename)
+        list_filename[0] = 's'
+        list_filename[1] = ':'
+        ubyte flen = string.copy(filenameptr, &list_filename+2)
+        c64.SETNAM(flen+2, list_filename)
         c64.SETLFS(1, drivenumber, 15)
         void c64.OPEN()
         c64.CLRCHN()
@@ -514,17 +564,24 @@ io_error:
 
     sub rename(ubyte drivenumber, uword oldfileptr, uword newfileptr) {
         ; -- rename a file on the drive
-        filename[0] = 'r'
-        filename[1] = ':'
-        ubyte flen_new = string.copy(newfileptr, &filename+2)
-        filename[flen_new+2] = '='
-        ubyte flen_old = string.copy(oldfileptr, &filename+3+flen_new)
-        c64.SETNAM(3+flen_new+flen_old, filename)
+        list_filename[0] = 'r'
+        list_filename[1] = ':'
+        ubyte flen_new = string.copy(newfileptr, &list_filename+2)
+        list_filename[flen_new+2] = '='
+        ubyte flen_old = string.copy(oldfileptr, &list_filename+3+flen_new)
+        c64.SETNAM(3+flen_new+flen_old, list_filename)
         c64.SETLFS(1, drivenumber, 15)
         void c64.OPEN()
         c64.CLRCHN()
         c64.CLOSE(1)
     }
 
-    str filename = "0:??????????????????????????????????????"
+    sub send_command(ubyte drivenumber, uword commandptr) {
+        ; -- send a dos command to the drive
+        c64.SETNAM(string.length(commandptr), commandptr)
+        c64.SETLFS(15, drivenumber, 15)
+        void c64.OPEN()
+        c64.CLRCHN()
+        c64.CLOSE(15)
+    }
 }