version 5.2

some programs are now 100% source compatible between C64 and Cx16 targets!
import libraries have been rena;med

.gitignore

@@ -1,8 +1,8 @@
 .idea/workspace.xml
 .idea/discord.xml
-/build/
-/dist/
-/output/
+build/
+dist/
+output/
 .*cache/
 *.directory
 *.prg
@@ -12,9 +12,9 @@
 *.vice-mon-list
 docs/build
 out/
-**/*.interp
-**/*.tokens
-
+parser/**/*.interp
+parser/**/*.tokens
+parser/**/*.java
 *.py[cod]
 *.egg
 *.egg-info
@@ -28,5 +28,4 @@ parsetab.py
 .attach_pid*
 
 .gradle
-build/
 /prog8compiler.jar

.idea/misc.xml

@@ -16,7 +16,7 @@
       </list>
     </option>
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="false" project-jdk-name="Kotlin SDK" project-jdk-type="KotlinSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="false" project-jdk-name="Kotlin SDK" project-jdk-type="KotlinSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>

.travis.yml

@@ -4,8 +4,8 @@ sudo: false
 # dist: xenial
 
 before_install:
-  - chmod +x gradlew
+  - chmod +x ./gradlew
 
 script:
-  - gradle test
+  - ./gradlew test
 

README.md

@@ -1,63 +1,73 @@
 [![saythanks](https://img.shields.io/badge/say-thanks-ff69b4.svg)](https://saythanks.io/to/irmen)
 [![Build Status](https://travis-ci.org/irmen/prog8.svg?branch=master)](https://travis-ci.org/irmen/prog8)
+[![Documentation](https://readthedocs.org/projects/prog8/badge/?version=latest)](https://prog8.readthedocs.io/)
 
-Prog8 - Structured Programming Language for 8-bit 6502/6510 microprocessors
-===========================================================================
+Prog8 - Structured Programming Language for 8-bit 6502/65c02 microprocessors
+============================================================================
 
 *Written by Irmen de Jong (irmen@razorvine.net)*
 
 *Software license: GNU GPL 3.0, see file LICENSE*
 
 
-This is a structured programming language for the 8-bit 6502/6510 microprocessor from the late 1970's and 1980's
+This is a structured programming language for the 8-bit 6502/6510/65c02 microprocessor from the late 1970's and 1980's
 as used in many home computers from that era. It is a medium to low level programming language,
-which aims to provide many conveniences over raw assembly code (even when using a macro assembler):
+which aims to provide many conveniences over raw assembly code (even when using a macro assembler).
 
-- reduction of source code length
+Documentation
+-------------
+Full documentation (syntax reference, how to use the language and the compiler, etc.) can be found at:
+https://prog8.readthedocs.io/
+
+
+What does Prog8 provide?
+------------------------
+
+- big reduction of source code length over raw assembly
 - modularity, symbol scoping, subroutines
 - various data types other than just bytes (16-bit words, floats, strings)
 - automatic variable allocations, automatic string and array variables and string sharing
-- subroutines with a input- and output parameter signature
-- constant folding in expressions
+- subroutines with an input- and output parameter signature
+- no stack frame allocations because parameters and local variables are automatically allocated statically
+- constant folding in expressions and other high-level program optimizations
 - conditional branches
-- 'when' statement to provide a concise jump table alternative to if/elseif chains
-- structs to group together sets of variables and manipulate them at once
 - floating point operations  (requires the C64 Basic ROM routines for this)
-- abstracting away low level aspects such as ZeroPage handling, program startup, explicit memory addresses
-- various code optimizations (code structure, logical and numerical expressions, unused code removal...)
-- inline assembly allows you to have full control when every cycle or byte matters
+- 'when' statement to provide a concise jump table alternative to if/elseif chains
 - many built-in functions such as ``sin``, ``cos``, ``rnd``, ``abs``, ``min``, ``max``, ``sqrt``, ``msb``, ``rol``, ``ror``, ``swap``, ``memset``, ``memcopy``, ``sort`` and ``reverse``
+- structs to group together sets of variables and manipulate them at once
+- convenience abstractions for low level aspects such as ZeroPage handling, program startup, explicit memory addresses
+- fast execution speed due to compilation to native assembly code
+- inline assembly allows you to have full control when every cycle or byte matters
 
-Rapid edit-compile-run-debug cycle:
+*Rapid edit-compile-run-debug cycle:*
 
-- use modern PC to work on
-- quick compilation times (seconds)
-- option to automatically run the program in the Vice emulator
+- use a modern PC to do the work on, use nice editors and enjoy quick compilation times
+- can automatically run the program in the Vice emulator after succesful compilation
 - breakpoints, that let the Vice emulator drop into the monitor if execution hits them
 - source code labels automatically loaded in Vice emulator so it can show them in disassembly
-- virtual machine that can execute compiled code directy on the host system,
-  without having to actually convert it to assembly to run on a real 6502
 
-It is mainly targeted at the Commodore-64 machine at this time.
-Contributions to add support for other 8-bit (or other?!) machines are welcome.
+*Two supported compiler targets* (contributions to improve these or to add support for other machines are welcome!):
 
-Documentation/manual
---------------------
-This describes the language, but also how to build and run the compiler. See https://prog8.readthedocs.io/
+- "c64": Commodore-64  (6510 CPU = almost a 6502), the main target.
+- "cx16": [CommanderX16](https://www.commanderx16.com)  (65c02 CPU) .
+- If you only use standard kernel and prog8 library routines, it is possible to compile the *exact same program* for both machines (just change the compiler target flag)!
 
-Required tools
---------------
+
+
+Additional required tools
+-------------------------
 
 [64tass](https://sourceforge.net/projects/tass64/) - cross assembler. Install this on your shell path.
 A recent .exe version of this tool for Windows can be obtained from my [clone](https://github.com/irmen/64tass/releases) of this project.
 For other platforms it is very easy to compile it yourself (make ; make install).
 
-A **Java runtime (jre or jdk), version 8 or newer**  is required to run a prepackaged version of the compiler.
+A **Java runtime (jre or jdk), version 11 or newer**  is required to run a prepackaged version of the compiler.
 If you want to build it from source, you'll need a Java SDK + Kotlin 1.3.x SDK (or for instance,
 IntelliJ IDEA with the Kotlin plugin).
 
-It's handy to have a C-64 emulator or a real C-64 to run the programs on. The compiler assumes the presence
-of the [Vice emulator](http://vice-emu.sourceforge.net/)
+It's handy to have an emulator (or a real machine perhaps!) to run the programs on. The compiler assumes the presence
+of the [Vice emulator](http://vice-emu.sourceforge.net/)  for the C64 target,
+and the [x16emu emulator](https://github.com/commanderx16/x16-emulator) for the CommanderX16 target.
 
 
 Example code
@@ -65,44 +75,45 @@ Example code
 
 This code calculates prime numbers using the Sieve of Eratosthenes algorithm::
 
-    %import c64utils
+    %import textio
     %zeropage basicsafe
-
+    
     main {
-
+    
         ubyte[256] sieve
-        ubyte candidate_prime = 2
-
+        ubyte candidate_prime = 2       ; is increased in the loop
+    
         sub start() {
-            memset(sieve, 256, false)
-
-            c64scr.print("prime numbers up to 255:\n\n")
+            ; clear the sieve, to reset starting situation on subsequent runs
+            memset(sieve, 256, false)   
+            ; calculate primes
+            txt.print("prime numbers up to 255:\n\n")
             ubyte amount=0
-            while true {
+            repeat {
                 ubyte prime = find_next_prime()
                 if prime==0
                     break
-                c64scr.print_ub(prime)
-                c64scr.print(", ")
+                txt.print_ub(prime)
+                txt.print(", ")
                 amount++
             }
-            c64.CHROUT('\n')
-            c64scr.print("number of primes (expected 54): ")
-            c64scr.print_ub(amount)
-            c64.CHROUT('\n')
+            txt.chrout('\n')
+            txt.print("number of primes (expected 54): ")
+            txt.print_ub(amount)
+            txt.chrout('\n')
         }
-
-
+    
         sub find_next_prime() -> ubyte {
-
             while sieve[candidate_prime] {
                 candidate_prime++
                 if candidate_prime==0
-                    return 0
+                    return 0        ; we wrapped; no more primes available in the sieve
             }
-
+    
+            ; found next one, mark the multiples and return it.
             sieve[candidate_prime] = true
             uword multiple = candidate_prime
+    
             while multiple < len(sieve) {
                 sieve[lsb(multiple)] = true
                 multiple += candidate_prime
@@ -112,11 +123,11 @@ This code calculates prime numbers using the Sieve of Eratosthenes algorithm::
     }
 
 
+
 when compiled an ran on a C-64 you'll get:
 
 ![c64 screen](docs/source/_static/primes_example.png)
 
-
 One of the included examples (wizzine.p8) animates a bunch of sprite balloons and looks like this:
 
 ![wizzine screen](docs/source/_static/wizzine.png)
@@ -128,3 +139,8 @@ Another example (cube3d-sprites.p8) draws the vertices of a rotating 3d cube:
 If you want to play a video game, a fully working Tetris clone is included in the examples:
 
 ![tehtriz_screen](docs/source/_static/tehtriz.png)
+
+The CommanderX16 compiler target is quite capable already too, here's a well known space ship 
+animated in 3D with hidden line removal, in the CommanderX16 emulator:
+
+![cobra3d](docs/source/_static/cobra3d.png)

compiler/build.gradle

@@ -1,11 +1,11 @@
 buildscript {
     dependencies {
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.61"
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.4.20"
     }
 }
 
 plugins {
-    // id "org.jetbrains.kotlin.jvm" version "1.3.61"
+    // id "org.jetbrains.kotlin.jvm" version "1.4.20"
     id 'application'
     id 'org.jetbrains.dokka' version "0.9.18"
     id 'com.github.johnrengelman.shadow' version '5.2.0'
@@ -15,8 +15,8 @@ plugins {
 apply plugin: "kotlin"
 apply plugin: "java"
 
-targetCompatibility = 1.8
-sourceCompatibility = 1.8
+targetCompatibility = 11
+sourceCompatibility = 11
 
 repositories {
     mavenLocal()
@@ -34,6 +34,7 @@ dependencies {
     implementation 'org.antlr:antlr4-runtime:4.8'
     implementation 'org.jetbrains.kotlinx:kotlinx-cli-jvm:0.1.0-dev-5'
     // implementation 'net.razorvine:ksim65:1.6'
+    // implementation "com.github.hypfvieh:dbus-java:3.2.0"
     implementation project(':parser')
 
     testImplementation "org.jetbrains.kotlin:kotlin-test-junit5"
@@ -44,7 +45,7 @@ dependencies {
 
 compileKotlin {
     kotlinOptions {
-        jvmTarget = "1.8"
+        jvmTarget = "11"
         // verbose = true
         // freeCompilerArgs += "-XXLanguage:+NewInference"
     }
@@ -52,7 +53,7 @@ compileKotlin {
 
 compileTestKotlin {
     kotlinOptions {
-        jvmTarget = "1.8"
+        jvmTarget = "11"
     }
 }
 
@@ -100,7 +101,7 @@ test {
 
     // Show test results.
     testLogging {
-        events "passed", "skipped", "failed"
+        events "skipped", "failed"
     }
 }
 
@@ -109,3 +110,7 @@ dokka {
     outputFormat = 'html'
     outputDirectory = "$buildDir/kdoc"
 }
+
+task wrapper(type: Wrapper) {
+    gradleVersion = '6.1.1'
+}

compiler/compiler.iml

@@ -8,7 +8,7 @@
       <sourceFolder url="file://$MODULE_DIR$/test" isTestSource="true" />
       <excludeFolder url="file://$MODULE_DIR$/build" />
     </content>
-    <orderEntry type="jdk" jdkName="openjdk-11" jdkType="JavaSDK" />
+    <orderEntry type="jdk" jdkName="11" jdkType="JavaSDK" />
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="library" name="KotlinJavaRuntime" level="project" />
     <orderEntry type="module" module-name="parser" />

compiler/res/prog8lib/c64/floats.asm

@@ -0,0 +1,676 @@
+; --- low level floating point assembly routines for the C64
+
+FL_ONE_const	.byte  129     			; 1.0
+FL_ZERO_const	.byte  0,0,0,0,0		; 0.0
+
+floats_store_reg	.byte  0		; temp storage
+
+
+ub2float	.proc
+		; -- convert ubyte in SCRATCH_ZPB1 to float at address A/Y
+		;    clobbers A, Y
+		stx  P8ZP_SCRATCH_REG
+		sta  P8ZP_SCRATCH_W2
+		sty  P8ZP_SCRATCH_W2+1
+		ldy  P8ZP_SCRATCH_B1
+		lda  #0
+		jsr  GIVAYF
+_fac_to_mem	ldx  P8ZP_SCRATCH_W2
+		ldy  P8ZP_SCRATCH_W2+1
+		jsr  MOVMF
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+b2float		.proc
+		; -- convert byte in SCRATCH_ZPB1 to float at address A/Y
+		;    clobbers A, Y
+		stx  P8ZP_SCRATCH_REG
+		sta  P8ZP_SCRATCH_W2
+		sty  P8ZP_SCRATCH_W2+1
+		lda  P8ZP_SCRATCH_B1
+		jsr  FREADSA
+		jmp  ub2float._fac_to_mem
+		.pend
+
+uw2float	.proc
+		; -- convert uword in SCRATCH_ZPWORD1 to float at address A/Y
+		stx  P8ZP_SCRATCH_REG
+		sta  P8ZP_SCRATCH_W2
+		sty  P8ZP_SCRATCH_W2+1
+		lda  P8ZP_SCRATCH_W1
+		ldy  P8ZP_SCRATCH_W1+1
+		jsr  GIVUAYFAY
+		jmp  ub2float._fac_to_mem
+		.pend
+
+w2float		.proc
+		; -- convert word in SCRATCH_ZPWORD1 to float at address A/Y
+		stx  P8ZP_SCRATCH_REG
+		sta  P8ZP_SCRATCH_W2
+		sty  P8ZP_SCRATCH_W2+1
+		ldy  P8ZP_SCRATCH_W1
+		lda  P8ZP_SCRATCH_W1+1
+		jsr  GIVAYF
+		jmp  ub2float._fac_to_mem
+		.pend
+
+
+cast_from_uw	.proc
+		; -- uword in A/Y into float var at (P8ZP_SCRATCH_W2)
+		stx  P8ZP_SCRATCH_REG
+		jsr  GIVUAYFAY
+		jmp  ub2float._fac_to_mem
+		.pend
+
+
+cast_from_w	.proc
+		; -- word in A/Y into float var at (P8ZP_SCRATCH_W2)
+		stx  P8ZP_SCRATCH_REG
+		jsr  GIVAYFAY
+		jmp  ub2float._fac_to_mem
+		.pend
+
+
+cast_from_ub	.proc
+		; -- ubyte in Y into float var at (P8ZP_SCRATCH_W2)
+		stx  P8ZP_SCRATCH_REG
+		jsr  FREADUY
+		jmp  ub2float._fac_to_mem
+		.pend
+
+
+cast_from_b	.proc
+		; -- byte in A into float var at (P8ZP_SCRATCH_W2)
+		stx  P8ZP_SCRATCH_REG
+		jsr  FREADSA
+		jmp  ub2float._fac_to_mem
+		.pend
+
+cast_as_uw_into_ya	.proc               ; also used for float 2 ub
+		; -- cast float at A/Y to uword into Y/A
+		jsr  MOVFM
+		jmp  cast_FAC1_as_uw_into_ya
+		.pend
+
+cast_as_w_into_ay	.proc               ; also used for float 2 b
+		; -- cast float at A/Y to word into A/Y
+		jsr  MOVFM
+		jmp  cast_FAC1_as_w_into_ay
+		.pend
+
+cast_FAC1_as_uw_into_ya	.proc               ; also used for float 2 ub
+		; -- cast fac1 to uword into Y/A
+		stx  P8ZP_SCRATCH_REG
+		jsr  GETADR     ; into Y/A
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+cast_FAC1_as_w_into_ay	.proc               ; also used for float 2 b
+		; -- cast fac1 to word into A/Y
+		stx  P8ZP_SCRATCH_REG
+		jsr  AYINT
+		ldy  $64
+		lda  $65
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+
+stack_b2float	.proc
+		; -- b2float operating on the stack
+		inx
+		lda  P8ESTACK_LO,x
+		stx  P8ZP_SCRATCH_REG
+		jsr  FREADSA
+		jmp  push_fac1._internal
+		.pend
+
+stack_w2float	.proc
+		; -- w2float operating on the stack
+		inx
+		ldy  P8ESTACK_LO,x
+		lda  P8ESTACK_HI,x
+		stx  P8ZP_SCRATCH_REG
+		jsr  GIVAYF
+		jmp  push_fac1._internal
+		.pend
+
+stack_ub2float	.proc
+		; -- ub2float operating on the stack
+		inx
+		lda  P8ESTACK_LO,x
+		stx  P8ZP_SCRATCH_REG
+		tay
+		lda  #0
+		jsr  GIVAYF
+		jmp  push_fac1._internal
+		.pend
+
+stack_uw2float	.proc
+		; -- uw2float operating on the stack
+		inx
+		lda  P8ESTACK_LO,x
+		ldy  P8ESTACK_HI,x
+		stx  P8ZP_SCRATCH_REG
+		jsr  GIVUAYFAY
+		jmp  push_fac1._internal
+		.pend
+
+stack_float2w	.proc               ; also used for float2b
+		jsr  pop_float_fac1
+		stx  P8ZP_SCRATCH_REG
+		jsr  AYINT
+		ldx  P8ZP_SCRATCH_REG
+		lda  $64
+		sta  P8ESTACK_HI,x
+		lda  $65
+		sta  P8ESTACK_LO,x
+		dex
+		rts
+		.pend
+
+stack_float2uw	.proc               ; also used for float2ub
+		jsr  pop_float_fac1
+		stx  P8ZP_SCRATCH_REG
+		jsr  GETADR
+		ldx  P8ZP_SCRATCH_REG
+		sta  P8ESTACK_HI,x
+		tya
+		sta  P8ESTACK_LO,x
+		dex
+		rts
+		.pend
+
+push_float	.proc
+		; ---- push mflpt5 in A/Y onto stack
+		; (taking 3 stack positions = 6 bytes of which 1 is padding)
+		sta  P8ZP_SCRATCH_W1
+		sty  P8ZP_SCRATCH_W1+1
+		ldy  #0
+		lda  (P8ZP_SCRATCH_W1),y
+		sta  P8ESTACK_LO,x
+		iny
+		lda  (P8ZP_SCRATCH_W1),y
+		sta  P8ESTACK_HI,x
+		dex
+		iny
+		lda  (P8ZP_SCRATCH_W1),y
+		sta  P8ESTACK_LO,x
+		iny
+		lda  (P8ZP_SCRATCH_W1),y
+		sta  P8ESTACK_HI,x
+		dex
+		iny
+		lda  (P8ZP_SCRATCH_W1),y
+		sta  P8ESTACK_LO,x
+		dex
+		rts
+		.pend
+
+pop_float	.proc
+		; ---- pops mflpt5 from stack to memory A/Y
+		; (frees 3 stack positions = 6 bytes of which 1 is padding)
+		sta  P8ZP_SCRATCH_W1
+		sty  P8ZP_SCRATCH_W1+1
+		ldy  #4
+		inx
+		lda  P8ESTACK_LO,x
+		sta  (P8ZP_SCRATCH_W1),y
+		dey
+		inx
+		lda  P8ESTACK_HI,x
+		sta  (P8ZP_SCRATCH_W1),y
+		dey
+		lda  P8ESTACK_LO,x
+		sta  (P8ZP_SCRATCH_W1),y
+		dey
+		inx
+		lda  P8ESTACK_HI,x
+		sta  (P8ZP_SCRATCH_W1),y
+		dey
+		lda  P8ESTACK_LO,x
+		sta  (P8ZP_SCRATCH_W1),y
+		rts
+		.pend
+
+pop_float_fac1	.proc
+		; -- pops float from stack into FAC1
+		lda  #<fmath_float1
+		ldy  #>fmath_float1
+		jsr  pop_float
+		lda  #<fmath_float1
+		ldy  #>fmath_float1
+		jmp  MOVFM
+		.pend
+
+copy_float	.proc
+		; -- copies the 5 bytes of the mflt value pointed to by SCRATCH_ZPWORD1,
+		;    into the 5 bytes pointed to by A/Y.  Clobbers A,Y.
+		sta  _target+1
+		sty  _target+2
+		ldy  #4
+_loop		lda  (P8ZP_SCRATCH_W1),y
+_target		sta  $ffff,y			; modified
+		dey
+		bpl  _loop
+		rts
+		.pend
+
+inc_var_f	.proc
+		; -- add 1 to float pointed to by A/Y
+		sta  P8ZP_SCRATCH_W1
+		sty  P8ZP_SCRATCH_W1+1
+		stx  P8ZP_SCRATCH_REG
+		jsr  MOVFM
+		lda  #<FL_ONE_const
+		ldy  #>FL_ONE_const
+		jsr  FADD
+		ldx  P8ZP_SCRATCH_W1
+		ldy  P8ZP_SCRATCH_W1+1
+		jsr  MOVMF
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+dec_var_f	.proc
+		; -- subtract 1 from float pointed to by A/Y
+		sta  P8ZP_SCRATCH_W1
+		sty  P8ZP_SCRATCH_W1+1
+		stx  P8ZP_SCRATCH_REG
+		lda  #<FL_ONE_const
+		ldy  #>FL_ONE_const
+		jsr  MOVFM
+		lda  P8ZP_SCRATCH_W1
+		ldy  P8ZP_SCRATCH_W1+1
+		jsr  FSUB
+		ldx  P8ZP_SCRATCH_W1
+		ldy  P8ZP_SCRATCH_W1+1
+		jsr  MOVMF
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+
+pop_2_floats_f2_in_fac1	.proc
+		; -- pop 2 floats from stack, load the second one in FAC1 as well
+		lda  #<fmath_float2
+		ldy  #>fmath_float2
+		jsr  pop_float
+		lda  #<fmath_float1
+		ldy  #>fmath_float1
+		jsr  pop_float
+		lda  #<fmath_float2
+		ldy  #>fmath_float2
+		jmp  MOVFM
+		.pend
+
+
+fmath_float1	.byte 0,0,0,0,0	; storage for a mflpt5 value
+fmath_float2	.byte 0,0,0,0,0	; storage for a mflpt5 value
+
+
+push_fac1	.proc
+		; -- push the float in FAC1 onto the stack
+		stx  P8ZP_SCRATCH_REG
+_internal	ldx  #<fmath_float1
+		ldy  #>fmath_float1
+		jsr  MOVMF
+		lda  #<fmath_float1
+		ldy  #>fmath_float1
+		ldx  P8ZP_SCRATCH_REG
+		jmp  push_float
+		.pend
+
+
+pow_f		.proc
+		; -- push f1 ** f2 on stack
+		lda  #<fmath_float2
+		ldy  #>fmath_float2
+		jsr  pop_float
+		lda  #<fmath_float1
+		ldy  #>fmath_float1
+		jsr  pop_float
+		stx  P8ZP_SCRATCH_REG
+		lda  #<fmath_float1
+		ldy  #>fmath_float1
+		jsr  CONUPK		; fac2 = float1
+		lda  #<fmath_float2
+		ldy  #>fmath_float2
+		jsr  FPWR
+		jmp  push_fac1._internal
+		.pend
+
+div_f		.proc
+		; -- push f1/f2 on stack
+		jsr  pop_2_floats_f2_in_fac1
+		stx  P8ZP_SCRATCH_REG
+		lda  #<fmath_float1
+		ldy  #>fmath_float1
+		jsr  FDIV
+		jmp  push_fac1._internal
+		.pend
+
+add_f		.proc
+		; -- push f1+f2 on stack
+		jsr  pop_2_floats_f2_in_fac1
+		stx  P8ZP_SCRATCH_REG
+		lda  #<fmath_float1
+		ldy  #>fmath_float1
+		jsr  FADD
+		jmp  push_fac1._internal
+		.pend
+
+sub_f		.proc
+		; -- push f1-f2 on stack
+		jsr  pop_2_floats_f2_in_fac1
+		stx  P8ZP_SCRATCH_REG
+		lda  #<fmath_float1
+		ldy  #>fmath_float1
+		jsr  FSUB
+		jmp  push_fac1._internal
+		.pend
+
+mul_f		.proc
+		; -- push f1*f2 on stack
+		jsr  pop_2_floats_f2_in_fac1
+		stx  P8ZP_SCRATCH_REG
+		lda  #<fmath_float1
+		ldy  #>fmath_float1
+		jsr  FMULT
+		jmp  push_fac1._internal
+		.pend
+
+neg_f		.proc
+		; -- toggle the sign bit on the stack
+		lda  P8ESTACK_HI+3,x
+		eor  #$80
+		sta  P8ESTACK_HI+3,x
+		rts
+		.pend
+
+var_fac1_less_f	.proc
+		; -- is the float in FAC1 < the variable AY?
+		stx  P8ZP_SCRATCH_REG
+		jsr  FCOMP
+		ldx  P8ZP_SCRATCH_REG
+		cmp  #255
+		beq  +
+		lda  #0
+		rts
++		lda  #1
+		rts
+		.pend
+
+var_fac1_lesseq_f	.proc
+		; -- is the float in FAC1 <= the variable AY?
+		stx  P8ZP_SCRATCH_REG
+		jsr  FCOMP
+		ldx  P8ZP_SCRATCH_REG
+		cmp  #0
+		beq  +
+		cmp  #255
+		beq  +
+		lda  #0
+		rts
++		lda  #1
+		rts
+		.pend
+
+var_fac1_greater_f	.proc
+		; -- is the float in FAC1 > the variable AY?
+		stx  P8ZP_SCRATCH_REG
+		jsr  FCOMP
+		ldx  P8ZP_SCRATCH_REG
+		cmp  #1
+		beq  +
+		lda  #0
++		rts
+		.pend
+
+var_fac1_greatereq_f	.proc
+		; -- is the float in FAC1 >= the variable AY?
+		stx  P8ZP_SCRATCH_REG
+		jsr  FCOMP
+		ldx  P8ZP_SCRATCH_REG
+		cmp  #0
+		beq  +
+		cmp  #1
+		beq  +
+		lda  #0
+		rts
++		lda  #1
+		rts
+		.pend
+
+var_fac1_notequal_f	.proc
+		; -- are the floats numbers in FAC1 and the variable AY *not* identical?
+		stx  P8ZP_SCRATCH_REG
+		jsr  FCOMP
+		ldx  P8ZP_SCRATCH_REG
+		and  #1
+		rts
+		.pend
+
+vars_equal_f	.proc
+		; -- are the mflpt5 numbers in P8ZP_SCRATCH_W1 and AY identical?
+		sta  P8ZP_SCRATCH_W2
+		sty  P8ZP_SCRATCH_W2+1
+		ldy  #0
+		lda  (P8ZP_SCRATCH_W1),y
+		cmp  (P8ZP_SCRATCH_W2),y
+		bne  _false
+		iny
+		lda  (P8ZP_SCRATCH_W1),y
+		cmp  (P8ZP_SCRATCH_W2),y
+		bne  _false
+		iny
+		lda  (P8ZP_SCRATCH_W1),y
+		cmp  (P8ZP_SCRATCH_W2),y
+		bne  _false
+		iny
+		lda  (P8ZP_SCRATCH_W1),y
+		cmp  (P8ZP_SCRATCH_W2),y
+		bne  _false
+		iny
+		lda  (P8ZP_SCRATCH_W1),y
+		cmp  (P8ZP_SCRATCH_W2),y
+		bne  _false
+		lda  #1
+		rts
+_false		lda  #0
+		rts
+		.pend
+
+equal_f		.proc
+		; -- are the two mflpt5 numbers on the stack identical?
+		inx
+		inx
+		inx
+		inx
+		lda  P8ESTACK_LO-3,x
+		cmp  P8ESTACK_LO,x
+		bne  _equals_false
+		lda  P8ESTACK_LO-2,x
+		cmp  P8ESTACK_LO+1,x
+		bne  _equals_false
+		lda  P8ESTACK_LO-1,x
+		cmp  P8ESTACK_LO+2,x
+		bne  _equals_false
+		lda  P8ESTACK_HI-2,x
+		cmp  P8ESTACK_HI+1,x
+		bne  _equals_false
+		lda  P8ESTACK_HI-1,x
+		cmp  P8ESTACK_HI+2,x
+		bne  _equals_false
+_equals_true	lda  #1
+_equals_store	inx
+		sta  P8ESTACK_LO+1,x
+		rts
+_equals_false	lda  #0
+		beq  _equals_store
+		.pend
+
+notequal_f	.proc
+		; -- are the two mflpt5 numbers on the stack different?
+		jsr  equal_f
+		eor  #1		; invert the result
+		sta  P8ESTACK_LO+1,x
+		rts
+		.pend
+
+vars_less_f	.proc
+		; -- is float in AY < float in P8ZP_SCRATCH_W2 ?
+		jsr  MOVFM
+		lda  P8ZP_SCRATCH_W2
+		ldy  P8ZP_SCRATCH_W2+1
+		stx  P8ZP_SCRATCH_REG
+		jsr  FCOMP
+		ldx  P8ZP_SCRATCH_REG
+		cmp  #255
+		bne  +
+		lda  #1
+		rts
++		lda  #0
+		rts
+		.pend
+
+vars_lesseq_f	.proc
+		; -- is float in AY <= float in P8ZP_SCRATCH_W2 ?
+		jsr  MOVFM
+		lda  P8ZP_SCRATCH_W2
+		ldy  P8ZP_SCRATCH_W2+1
+		stx  P8ZP_SCRATCH_REG
+		jsr  FCOMP
+		ldx  P8ZP_SCRATCH_REG
+		cmp  #255
+		bne  +
+-		lda  #1
+		rts
++		cmp  #0
+		beq  -
+		lda  #0
+		rts
+		.pend
+
+less_f		.proc
+		; -- is f1 < f2?
+		jsr  compare_floats
+		cmp  #255
+		beq  compare_floats._return_true
+		bne  compare_floats._return_false
+		.pend
+
+
+lesseq_f	.proc
+		; -- is f1 <= f2?
+		jsr  compare_floats
+		cmp  #255
+		beq  compare_floats._return_true
+		cmp  #0
+		beq  compare_floats._return_true
+		bne  compare_floats._return_false
+		.pend
+
+greater_f	.proc
+		; -- is f1 > f2?
+		jsr  compare_floats
+		cmp  #1
+		beq  compare_floats._return_true
+		bne  compare_floats._return_false
+		.pend
+
+greatereq_f	.proc
+		; -- is f1 >= f2?
+		jsr  compare_floats
+		cmp  #1
+		beq  compare_floats._return_true
+		cmp  #0
+		beq  compare_floats._return_true
+		bne  compare_floats._return_false
+		.pend
+
+compare_floats	.proc
+		lda  #<fmath_float2
+		ldy  #>fmath_float2
+		jsr  pop_float
+		lda  #<fmath_float1
+		ldy  #>fmath_float1
+		jsr  pop_float
+		lda  #<fmath_float1
+		ldy  #>fmath_float1
+		jsr  MOVFM		; fac1 = flt1
+		lda  #<fmath_float2
+		ldy  #>fmath_float2
+		stx  P8ZP_SCRATCH_REG
+		jsr  FCOMP		; A = flt1 compared with flt2 (0=equal, 1=flt1>flt2, 255=flt1<flt2)
+		ldx  P8ZP_SCRATCH_REG
+		rts
+_return_false	lda  #0
+_return_result  sta  P8ESTACK_LO,x
+		dex
+		rts
+_return_true	lda  #1
+		bne  _return_result
+		.pend
+
+set_array_float_from_fac1	.proc
+		; -- set the float in FAC1 in the array (index in A, array in P8ZP_SCRATCH_W1)
+		sta  P8ZP_SCRATCH_B1
+		asl  a
+		asl  a
+		clc
+		adc  P8ZP_SCRATCH_B1
+		ldy  P8ZP_SCRATCH_W1+1
+		clc
+		adc  P8ZP_SCRATCH_W1
+		bcc  +
+		iny
++		stx  floats_store_reg
+		tax
+		jsr  MOVMF
+		ldx  floats_store_reg
+		rts
+		.pend
+
+
+set_0_array_float	.proc
+		; -- set a float in an array to zero (index in A, array in P8ZP_SCRATCH_W1)
+		sta  P8ZP_SCRATCH_B1
+		asl  a
+		asl  a
+		clc
+		adc  P8ZP_SCRATCH_B1
+		tay
+		lda  #0
+		sta  (P8ZP_SCRATCH_W1),y
+		iny
+		sta  (P8ZP_SCRATCH_W1),y
+		iny
+		sta  (P8ZP_SCRATCH_W1),y
+		iny
+		sta  (P8ZP_SCRATCH_W1),y
+		iny
+		sta  (P8ZP_SCRATCH_W1),y
+		rts
+		.pend
+
+
+set_array_float		.proc
+		; -- set a float in an array to a value (index in A, float in P8ZP_SCRATCH_W1, array in P8ZP_SCRATCH_W2)
+		sta  P8ZP_SCRATCH_B1
+		asl  a
+		asl  a
+		clc
+		adc  P8ZP_SCRATCH_B1
+		adc  P8ZP_SCRATCH_W2
+		ldy  P8ZP_SCRATCH_W2+1
+		bcc  +
+		iny
++		jmp  copy_float
+			; -- copies the 5 bytes of the mflt value pointed to by SCRATCH_ZPWORD1,
+			;    into the 5 bytes pointed to by A/Y.  Clobbers A,Y.
+		.pend
+
+

compiler/res/prog8lib/c64/floats.p8

@@ -0,0 +1,218 @@
+; 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
+
+%target c64
+%option enable_floats
+
+floats {
+	; ---- this block contains C-64 floating point related functions ----
+
+        const float  PI     = 3.141592653589793
+        const float  TWOPI  = 6.283185307179586
+
+
+; ---- C64 basic and kernal ROM float constants and functions ----
+
+		; note: the fac1 and fac2 are working registers and take 6 bytes each,
+		; floats in memory  (and rom) are stored in 5-byte MFLPT packed format.
+
+		; constants in five-byte "mflpt" format in the BASIC ROM
+		&float  FL_PIVAL	= $aea8  ; 3.1415926...
+		&float  FL_N32768	= $b1a5  ; -32768
+		&float  FL_FONE		= $b9bc  ; 1
+		&float  FL_SQRHLF	= $b9d6  ; SQR(2) / 2
+		&float  FL_SQRTWO	= $b9db  ; SQR(2)
+		&float  FL_NEGHLF	= $b9e0  ; -.5
+		&float  FL_LOG2		= $b9e5  ; LOG(2)
+		&float  FL_TENC		= $baf9  ; 10
+		&float  FL_NZMIL	= $bdbd  ; 1e9 (1 billion)
+		&float  FL_FHALF	= $bf11  ; .5
+		&float  FL_LOGEB2	= $bfbf  ; 1 / LOG(2)
+		&float  FL_PIHALF	= $e2e0  ; PI / 2
+		&float  FL_TWOPI	= $e2e5  ; 2 * PI
+		&float  FL_FR4		= $e2ea  ; .25
+		; oddly enough, 0.0 isn't available in the kernel.
+
+
+; note: fac1/2 might get clobbered even if not mentioned in the function's name.
+; note: for subtraction and division, the left operand is in fac2, the right operand in fac1.
+
+romsub $bba2 = MOVFM(uword mflpt @ AY) clobbers(A,Y)        ; load mflpt value from memory  in A/Y into fac1
+romsub $bba6 = FREADMEM() clobbers(A,Y)                     ; load mflpt value from memory  in $22/$23 into fac1
+romsub $ba8c = CONUPK(uword mflpt @ AY) clobbers(A,Y)       ; load mflpt value from memory  in A/Y into fac2
+romsub $ba90 = FAREADMEM() clobbers(A,Y)                    ; load mflpt value from memory  in $22/$23 into fac2
+romsub $bbfc = MOVFA() clobbers(A,X)                        ; copy fac2 to fac1
+romsub $bc0c = MOVAF() clobbers(A,X)                        ; copy fac1 to fac2  (rounded)
+romsub $bc0f = MOVEF() clobbers(A,X)                        ; copy fac1 to fac2
+romsub $bbd4 = MOVMF(uword mflpt @ XY) clobbers(A,Y)        ; store fac1 to memory  X/Y as 5-byte mflpt
+
+; fac1-> signed word in Y/A (might throw ILLEGAL QUANTITY)
+; (tip: use floats.FTOSWRDAY to get A/Y output; lo/hi switched to normal little endian order)
+romsub $b1aa = FTOSWORDYA() clobbers(X) -> ubyte @ Y, ubyte @ A       ; note: calls AYINT.
+
+; fac1 -> unsigned word in Y/A (might throw ILLEGAL QUANTITY) (result also in $14/15)
+; (tip: use floats.GETADRAY to get A/Y output; lo/hi switched to normal little endian order)
+romsub $b7f7 = GETADR() clobbers(X) -> ubyte @ Y, ubyte @ A
+
+romsub $bc9b = QINT() clobbers(A,X,Y)           ; fac1 -> 4-byte signed integer in 98-101 ($62-$65), with the MSB FIRST.
+romsub $b1bf = AYINT() clobbers(A,X,Y)          ; fac1-> signed word in 100-101 ($64-$65) MSB FIRST. (might throw ILLEGAL QUANTITY)
+
+; GIVAYF: signed word in Y/A (note different lsb/msb order) -> float in fac1
+; (tip: use floats.GIVAYFAY to use A/Y input; lo/hi switched to normal order)
+; there is also floats.GIVUAYFAY - unsigned word in A/Y (lo/hi) to fac1
+; there is also floats.FREADS32  that reads from 98-101 ($62-$65) MSB FIRST
+; there is also floats.FREADUS32  that reads from 98-101 ($62-$65) MSB FIRST
+; there is also floats.FREADS24AXY  that reads signed int24 into fac1 from A/X/Y (lo/mid/hi bytes)
+romsub $b391 = GIVAYF(ubyte lo @ Y, ubyte hi @ A) clobbers(A,X,Y)
+
+romsub $b3a2 = FREADUY(ubyte value @ Y) clobbers(A,X,Y)     ; 8 bit unsigned Y -> float in fac1
+romsub $bc3c = FREADSA(byte value @ A) clobbers(A,X,Y)      ; 8 bit signed A -> float in fac1
+romsub $b7b5 = FREADSTR(ubyte length @ A) clobbers(A,X,Y)   ; str -> fac1, $22/23 must point to string, A=string length
+romsub $aabc = FPRINTLN() clobbers(A,X,Y)                   ; print string of fac1, on one line (= with newline) destroys fac1.  (consider FOUT + STROUT as well)
+romsub $bddd = FOUT() clobbers(X) -> uword @ AY             ; fac1 -> string, address returned in AY ($0100)
+
+romsub $b849 = FADDH() clobbers(A,X,Y)                      ; fac1 += 0.5, for rounding- call this before INT
+romsub $bae2 = MUL10() clobbers(A,X,Y)                      ; fac1 *= 10
+romsub $bafe = DIV10() clobbers(A,X,Y)                      ; fac1 /= 10 , CAUTION: result is always positive!
+romsub $bc5b = FCOMP(uword mflpt @ AY) clobbers(X,Y) -> ubyte @ A   ; A = compare fac1 to mflpt in A/Y, 0=equal 1=fac1 is greater, 255=fac1 is less than
+
+romsub $b86a = FADDT() clobbers(A,X,Y)                      ; fac1 += fac2
+romsub $b867 = FADD(uword mflpt @ AY) clobbers(A,X,Y)       ; fac1 += mflpt value from A/Y
+romsub $b853 = FSUBT() clobbers(A,X,Y)                      ; fac1 = fac2-fac1   mind the order of the operands
+romsub $b850 = FSUB(uword mflpt @ AY) clobbers(A,X,Y)       ; fac1 = mflpt from A/Y - fac1
+romsub $ba2b = FMULTT() clobbers(A,X,Y)                     ; fac1 *= fac2
+romsub $ba28 = FMULT(uword mflpt @ AY) clobbers(A,X,Y)      ; fac1 *= mflpt value from A/Y
+romsub $bb12 = FDIVT() clobbers(A,X,Y)                      ; fac1 = fac2/fac1  (remainder in fac2)  mind the order of the operands
+romsub $bb0f = FDIV(uword mflpt @ AY) clobbers(A,X,Y)       ; fac1 = mflpt in A/Y / fac1  (remainder in fac2)
+romsub $bf7b = FPWRT() clobbers(A,X,Y)                      ; fac1 = fac2 ** fac1
+romsub $bf78 = FPWR(uword mflpt @ AY) clobbers(A,X,Y)       ; fac1 = fac2 ** mflpt from A/Y
+romsub $bd7e = FINLOG(byte value @A) clobbers (A, X, Y)     ; fac1 += signed byte in A
+
+romsub $aed4 = NOTOP() clobbers(A,X,Y)                      ; fac1 = NOT(fac1)
+romsub $bccc = INT() clobbers(A,X,Y)                        ; INT() truncates, use FADDH first to round instead of trunc
+romsub $b9ea = LOG() clobbers(A,X,Y)                        ; fac1 = LN(fac1)  (natural log)
+romsub $bc39 = SGN() clobbers(A,X,Y)                        ; fac1 = SGN(fac1), result of SIGN (-1, 0 or 1)
+romsub $bc2b = SIGN() -> ubyte @ A                          ; SIGN(fac1) to A, $ff, $0, $1 for negative, zero, positive
+romsub $bc58 = ABS()                                        ; fac1 = ABS(fac1)
+romsub $bf71 = SQR() clobbers(A,X,Y)                        ; fac1 = SQRT(fac1)
+romsub $bf74 = SQRA() clobbers(A,X,Y)                       ; fac1 = SQRT(fac2)
+romsub $bfed = EXP() clobbers(A,X,Y)                        ; fac1 = EXP(fac1)  (e ** fac1)
+romsub $bfb4 = NEGOP() clobbers(A)                          ; switch the sign of fac1
+romsub $e097 = RND() clobbers(A,X,Y)                        ; fac1 = RND(fac1) float random number generator
+romsub $e264 = COS() clobbers(A,X,Y)                        ; fac1 = COS(fac1)
+romsub $e26b = SIN() clobbers(A,X,Y)                        ; fac1 = SIN(fac1)
+romsub $e2b4 = TAN() clobbers(A,X,Y)                        ; fac1 = TAN(fac1)
+romsub $e30e = ATN() clobbers(A,X,Y)                        ; fac1 = ATN(fac1)
+
+
+
+asmsub  FREADS32() clobbers(A,X,Y)  {
+	; ---- fac1 = signed int32 from $62-$65 big endian (MSB FIRST)
+	%asm {{
+		lda  $62
+		eor  #$ff
+		asl  a
+		lda  #0
+		ldx  #$a0
+		jmp  $bc4f		; internal BASIC routine
+	}}
+}
+
+asmsub  FREADUS32  () clobbers(A,X,Y)  {
+	; ---- fac1 = uint32 from $62-$65 big endian (MSB FIRST)
+	%asm {{
+		sec
+		lda  #0
+		ldx  #$a0
+		jmp  $bc4f		; internal BASIC routine
+	}}
+}
+
+asmsub  FREADS24AXY  (ubyte lo @ A, ubyte mid @ X, ubyte hi @ Y) clobbers(A,X,Y)  {
+	; ---- fac1 = signed int24 (A/X/Y contain lo/mid/hi bytes)
+	;      note: there is no FREADU24AXY (unsigned), use FREADUS32 instead.
+	%asm {{
+		sty  $62
+		stx  $63
+		sta  $64
+		lda  $62
+		eor  #$FF
+		asl  a
+		lda  #0
+		sta  $65
+		ldx  #$98
+		jmp  $bc4f		; internal BASIC routine
+	}}
+}
+
+asmsub  GIVUAYFAY  (uword value @ AY) clobbers(A,X,Y)  {
+	; ---- unsigned 16 bit word in A/Y (lo/hi) to fac1
+	%asm {{
+		sty  $62
+		sta  $63
+		ldx  #$90
+		sec
+		jmp  $bc49		; internal BASIC routine
+	}}
+}
+
+asmsub  GIVAYFAY  (uword value @ AY) clobbers(A,X,Y)  {
+	; ---- signed 16 bit word in A/Y (lo/hi) to float in fac1
+	%asm {{
+		sta  P8ZP_SCRATCH_REG
+		tya
+		ldy  P8ZP_SCRATCH_REG
+		jmp  GIVAYF		; this uses the inverse order, Y/A
+	}}
+}
+
+asmsub  FTOSWRDAY  () clobbers(X) -> uword @ AY  {
+	; ---- fac1 to signed word in A/Y
+	%asm {{
+		jsr  FTOSWORDYA	; note the inverse Y/A order
+		sta  P8ZP_SCRATCH_REG
+		tya
+		ldy  P8ZP_SCRATCH_REG
+		rts
+	}}
+}
+
+asmsub  GETADRAY  () clobbers(X) -> uword @ AY  {
+	; ---- fac1 to unsigned word in A/Y
+	%asm {{
+		jsr  GETADR		; this uses the inverse order, Y/A
+		sta  P8ZP_SCRATCH_B1
+		tya
+		ldy  P8ZP_SCRATCH_B1
+		rts
+	}}
+}
+
+sub  print_f  (float value) {
+	; ---- prints the floating point value (without a newline).
+	%asm {{
+		stx  floats_store_reg
+		lda  #<value
+		ldy  #>value
+		jsr  MOVFM		; load float into fac1
+		jsr  FOUT		; fac1 to string in A/Y
+		sta  P8ZP_SCRATCH_W1
+		sty  P8ZP_SCRATCH_W1+1
+		ldy  #0
+-		lda  (P8ZP_SCRATCH_W1),y
+		beq  +
+		jsr  c64.CHROUT
+		iny
+		bne  -
++		ldx  floats_store_reg
+		rts
+	}}
+}
+
+%asminclude "library:c64/floats.asm", ""
+%asminclude "library:c64/floats_funcs.asm", ""
+
+}

compiler/res/prog8lib/c64/floats_funcs.asm

@@ -0,0 +1,437 @@
+; --- floating point builtin functions
+
+
+abs_f_stack	.proc
+		; -- push abs(AY) on stack
+		jsr  floats.MOVFM
+		jsr  floats.ABS
+		jmp  push_fac1
+		.pend
+
+abs_f_fac1	.proc
+		; -- FAC1 = abs(AY)
+		jsr  floats.MOVFM
+		jmp  floats.ABS
+		.pend
+
+func_atan_stack	.proc
+		jsr  func_atan_fac1
+		jmp  push_fac1
+		.pend
+
+func_atan_fac1	.proc
+		jsr  MOVFM
+		stx  P8ZP_SCRATCH_REG
+		jsr  ATN
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+func_ceil_stack	.proc
+		jsr  func_ceil_fac1
+		jmp  push_fac1
+		.pend
+
+func_ceil_fac1	.proc
+		; -- ceil: tr = int(f); if tr==f -> return  else return tr+1
+		jsr  MOVFM
+		stx  P8ZP_SCRATCH_REG
+		ldx  #<fmath_float1
+		ldy  #>fmath_float1
+		jsr  MOVMF
+		jsr  INT
+		lda  #<fmath_float1
+		ldy  #>fmath_float1
+		jsr  FCOMP
+		cmp  #0
+		beq  +
+		lda  #<FL_ONE_const
+		ldy  #>FL_ONE_const
+		jsr  FADD
++		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+func_floor_stack	.proc
+		jsr  func_floor_fac1
+		jmp  push_fac1
+		.pend
+
+func_floor_fac1	.proc
+		jsr  MOVFM
+		stx  P8ZP_SCRATCH_REG
+		jsr  INT
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+func_round_stack	.proc
+		jsr  func_round_fac1
+		jmp  push_fac1
+		.pend
+
+func_round_fac1	.proc
+		jsr  MOVFM
+		stx  P8ZP_SCRATCH_REG
+		jsr  FADDH
+		jsr  INT
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+func_sin_stack	.proc
+		jsr  func_sin_fac1
+		jmp  push_fac1
+		.pend
+
+func_sin_fac1	.proc
+		jsr  MOVFM
+		stx  P8ZP_SCRATCH_REG
+		jsr  SIN
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+func_cos_stack	.proc
+		jsr  func_cos_fac1
+		jmp  push_fac1
+		.pend
+
+func_cos_fac1	.proc
+		jsr  MOVFM
+		stx  P8ZP_SCRATCH_REG
+		jsr  COS
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+func_tan_stack	.proc
+		jsr  func_tan_fac1
+		jmp  push_fac1
+		.pend
+
+func_tan_fac1	.proc
+		jsr  MOVFM
+		stx  P8ZP_SCRATCH_REG
+		jsr  TAN
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+func_rad_stack	.proc
+		jsr  func_rad_fac1
+		jmp  push_fac1
+		.pend
+
+func_rad_fac1	.proc
+		; -- convert degrees to radians (d * pi / 180)
+		jsr  MOVFM
+		stx  P8ZP_SCRATCH_REG
+		lda  #<_pi_div_180
+		ldy  #>_pi_div_180
+		jsr  FMULT
+		ldx  P8ZP_SCRATCH_REG
+		rts
+_pi_div_180	.byte 123, 14, 250, 53, 18		; pi / 180
+		.pend
+
+func_deg_stack	.proc
+		jsr  func_deg_fac1
+		jmp  push_fac1
+		.pend
+
+func_deg_fac1	.proc
+		; -- convert radians to degrees (d * (1/ pi * 180))
+		jsr  MOVFM
+		stx  P8ZP_SCRATCH_REG
+		lda  #<_one_over_pi_div_180
+		ldy  #>_one_over_pi_div_180
+		jsr  FMULT
+		ldx  P8ZP_SCRATCH_REG
+		rts
+_one_over_pi_div_180	.byte 134, 101, 46, 224, 211		; 1 / (pi * 180)
+		.pend
+
+func_ln_stack	.proc
+		jsr  func_ln_fac1
+		jmp  push_fac1
+		.pend
+
+func_ln_fac1	.proc
+		jsr  MOVFM
+		stx  P8ZP_SCRATCH_REG
+		jsr  LOG
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+func_log2_stack	.proc
+		jsr  func_log2_fac1
+		jmp  push_fac1
+		.pend
+
+func_log2_fac1	.proc
+		jsr  MOVFM
+		stx  P8ZP_SCRATCH_REG
+		jsr  LOG
+		jsr  MOVEF
+		lda  #<FL_LOG2
+		ldy  #>FL_LOG2
+		jsr  MOVFM
+		jsr  FDIVT
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+func_sign_f_stack	.proc
+		jsr  func_sign_f_into_A
+		sta  P8ESTACK_LO,x
+		dex
+		rts
+		.pend
+
+func_sign_f_into_A	.proc
+		jsr  MOVFM
+		jmp  SIGN
+		.pend
+
+func_sqrt_stack	.proc
+		jsr  func_sqrt_fac1
+		jmp  push_fac1
+		.pend
+
+func_sqrt_fac1	.proc
+		jsr  MOVFM
+		stx  P8ZP_SCRATCH_REG
+		jsr  SQR
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+func_rndf_stack	.proc
+		jsr  func_rndf_fac1
+		jmp  push_fac1
+		.pend
+
+func_rndf_fac1	.proc
+		stx  P8ZP_SCRATCH_REG
+		lda  #1
+		jsr  FREADSA
+		jsr  RND		; rng into fac1
+		ldx  P8ZP_SCRATCH_REG
+		rts
+		.pend
+
+func_swap_f	.proc
+		; -- swap floats pointed to by SCRATCH_ZPWORD1, SCRATCH_ZPWORD2
+		ldy  #4
+-               lda  (P8ZP_SCRATCH_W1),y
+		pha
+		lda  (P8ZP_SCRATCH_W2),y
+		sta  (P8ZP_SCRATCH_W1),y
+		pla
+		sta  (P8ZP_SCRATCH_W2),y
+		dey
+		bpl  -
+		rts
+		.pend
+
+func_reverse_f	.proc
+		; --- reverse an array of floats (array in P8ZP_SCRATCH_W1, num elements in A)
+_left_index = P8ZP_SCRATCH_W2
+_right_index = P8ZP_SCRATCH_W2+1
+_loop_count = P8ZP_SCRATCH_REG
+		pha
+		jsr  a_times_5
+		sec
+		sbc  #5
+		sta  _right_index
+		lda  #0
+		sta  _left_index
+		pla
+		lsr  a
+		sta  _loop_count
+_loop		; push the left indexed float on the stack
+		ldy  _left_index
+		lda  (P8ZP_SCRATCH_W1),y
+		pha
+		iny
+		lda  (P8ZP_SCRATCH_W1),y
+		pha
+		iny
+		lda  (P8ZP_SCRATCH_W1),y
+		pha
+		iny
+		lda  (P8ZP_SCRATCH_W1),y
+		pha
+		iny
+		lda  (P8ZP_SCRATCH_W1),y
+		pha
+		; copy right index float to left index float
+		ldy  _right_index
+		lda  (P8ZP_SCRATCH_W1),y
+		ldy  _left_index
+		sta  (P8ZP_SCRATCH_W1),y
+		inc  _left_index
+		inc  _right_index
+		ldy  _right_index
+		lda  (P8ZP_SCRATCH_W1),y
+		ldy  _left_index
+		sta  (P8ZP_SCRATCH_W1),y
+		inc  _left_index
+		inc  _right_index
+		ldy  _right_index
+		lda  (P8ZP_SCRATCH_W1),y
+		ldy  _left_index
+		sta  (P8ZP_SCRATCH_W1),y
+		inc  _left_index
+		inc  _right_index
+		ldy  _right_index
+		lda  (P8ZP_SCRATCH_W1),y
+		ldy  _left_index
+		sta  (P8ZP_SCRATCH_W1),y
+		inc  _left_index
+		inc  _right_index
+		ldy  _right_index
+		lda  (P8ZP_SCRATCH_W1),y
+		ldy  _left_index
+		sta  (P8ZP_SCRATCH_W1),y
+		; pop the float off the stack into the right index float
+		ldy  _right_index
+		pla
+		sta  (P8ZP_SCRATCH_W1),y
+		dey
+		pla
+		sta  (P8ZP_SCRATCH_W1),y
+		dey
+		pla
+		sta  (P8ZP_SCRATCH_W1),y
+		dey
+		pla
+		sta  (P8ZP_SCRATCH_W1),y
+		dey
+		pla
+		sta  (P8ZP_SCRATCH_W1),y
+		inc  _left_index
+		lda  _right_index
+		sec
+		sbc  #9
+		sta  _right_index
+		dec  _loop_count
+		bne  _loop
+		rts
+
+		.pend
+
+
+
+a_times_5	.proc
+		sta  P8ZP_SCRATCH_B1
+		asl  a
+		asl  a
+		clc
+		adc  P8ZP_SCRATCH_B1
+		rts
+		.pend
+
+func_any_f_into_A	.proc
+		jsr  a_times_5
+		jmp  prog8_lib.func_any_b_into_A
+		.pend
+
+func_all_f_into_A	.proc
+		jsr  a_times_5
+		jmp  prog8_lib.func_all_b_into_A
+		.pend
+
+func_any_f_stack	.proc
+		jsr  a_times_5
+		jmp  prog8_lib.func_any_b_stack
+		.pend
+
+func_all_f_stack	.proc
+		jsr  a_times_5
+		jmp  prog8_lib.func_all_b_stack
+		.pend
+
+func_max_f_stack	.proc
+		jsr  func_max_f_fac1
+		jmp  push_fac1
+		.pend
+
+func_max_f_fac1	.proc
+		; -- max(array) -> fac1,  array in P8ZP_SCRATCH_W1, num elts in A
+_loop_count = P8ZP_SCRATCH_REG
+		stx  floats_store_reg
+		sta  _loop_count
+		lda  #255
+		sta  _minmax_cmp+1		; modifying
+		lda  #<_largest_neg_float
+		ldy  #>_largest_neg_float
+_minmax_entry	jsr  MOVFM
+-		lda  P8ZP_SCRATCH_W1
+		ldy  P8ZP_SCRATCH_W1+1
+		jsr  FCOMP
+_minmax_cmp	cmp  #255			; modified
+		bne  +
+		lda  P8ZP_SCRATCH_W1
+		ldy  P8ZP_SCRATCH_W1+1
+		jsr  MOVFM
++		lda  P8ZP_SCRATCH_W1
+		clc
+		adc  #5
+		sta  P8ZP_SCRATCH_W1
+		bcc  +
+		inc  P8ZP_SCRATCH_W1+1
++		dec  _loop_count
+		bne  -
+		ldx  floats_store_reg
+		rts
+_largest_neg_float	.byte 255,255,255,255,255		; largest negative float -1.7014118345e+38
+		.pend
+
+func_min_f_stack	.proc
+		jsr  func_min_f_fac1
+		jmp  push_fac1
+		.pend
+
+func_min_f_fac1	.proc
+		; -- min(array) -> fac1,  array in P8ZP_SCRATCH_W1, num elts in A
+		sta  func_max_f_fac1._loop_count
+		lda  #1
+		sta  func_max_f_fac1._minmax_cmp+1
+		lda  #<_largest_pos_float
+		ldy  #>_largest_pos_float
+		jmp  func_max_f_fac1._minmax_entry
+_largest_pos_float	.byte  255,127,255,255,255		; largest positive float
+		rts
+		.pend
+
+
+func_sum_f_stack	.proc
+		jsr  func_sum_f_fac1
+		jmp  push_fac1
+		.pend
+
+func_sum_f_fac1	.proc
+		; -- sum(array) -> fac1,  array in P8ZP_SCRATCH_W1, num elts in A
+_loop_count = P8ZP_SCRATCH_REG
+		stx  floats_store_reg
+		sta  _loop_count
+		lda  #<FL_ZERO_const
+		ldy  #>FL_ZERO_const
+		jsr  MOVFM
+-		lda  P8ZP_SCRATCH_W1
+		ldy  P8ZP_SCRATCH_W1+1
+		jsr  FADD
+		lda  P8ZP_SCRATCH_W1
+		clc
+		adc  #5
+		sta  P8ZP_SCRATCH_W1
+		bcc  +
+		inc  P8ZP_SCRATCH_W1+1
++		dec  _loop_count
+		bne  -
+		ldx  floats_store_reg
+		rts
+		.pend

compiler/res/prog8lib/c64/graphics.p8

@@ -0,0 +1,253 @@
+%target c64
+%import textio
+
+; bitmap pixel graphics module for the C64
+; only black/white monchrome 320x200 for now
+; assumes bitmap screen memory is $2000-$3fff
+
+graphics {
+    const uword BITMAP_ADDRESS = $2000
+    const uword WIDTH = 320
+    const ubyte HEIGHT = 200
+
+    sub enable_bitmap_mode() {
+        ; enable bitmap screen, erase it and set colors to black/white.
+        c64.SCROLY = %00111011
+        c64.SCROLX = %00001000
+        c64.VMCSB = (c64.VMCSB & %11110000) | %00001000   ; $2000-$3fff
+        clear_screen(1, 0)
+    }
+
+    sub disable_bitmap_mode() {
+        ; enables text mode, erase the text screen, color white
+        c64.SCROLY = %00011011
+        c64.SCROLX = %00001000
+        c64.VMCSB = (c64.VMCSB & %11110000) | %00000100   ; $1000-$2fff
+        txt.fill_screen(' ', 1)
+    }
+
+    sub clear_screen(ubyte pixelcolor, ubyte bgcolor) {
+        memset(BITMAP_ADDRESS, 320*200/8, 0)
+        txt.fill_screen(pixelcolor << 4 | bgcolor, 0)
+    }
+
+    sub line(uword @zp x1, ubyte @zp y1, uword @zp x2, ubyte @zp y2) {
+        ; Bresenham algorithm.
+        ; This code special cases various quadrant loops to allow simple ++ and -- operations.
+        ; TODO rewrite this in optimized assembly
+        if y1>y2 {
+            ; make sure dy is always positive to avoid 8 instead of just 4 special cases
+            swap(x1, x2)
+            swap(y1, y2)
+        }
+        word @zp d = 0
+        ubyte positive_ix = true
+        word @zp dx = x2-x1 as word
+        word @zp dy = y2-y1
+        if dx < 0 {
+            dx = -dx
+            positive_ix = false
+        }
+        dx *= 2
+        dy *= 2
+        internal_plotx = x1
+
+        if dx >= dy {
+            if positive_ix {
+                repeat {
+                    internal_plot(y1)
+                    if internal_plotx==x2
+                        return
+                    internal_plotx++
+                    d += dy
+                    if d > dx {
+                        y1++
+                        d -= dx
+                    }
+                }
+            } else {
+                repeat {
+                    internal_plot(y1)
+                    if internal_plotx==x2
+                        return
+                    internal_plotx--
+                    d += dy
+                    if d > dx {
+                        y1++
+                        d -= dx
+                    }
+                }
+            }
+        }
+        else {
+            if positive_ix {
+                repeat {
+                    internal_plot(y1)
+                    if y1 == y2
+                        return
+                    y1++
+                    d += dx
+                    if d > dy {
+                        internal_plotx++
+                        d -= dy
+                    }
+                }
+            } else {
+                repeat {
+                    internal_plot(y1)
+                    if y1 == y2
+                        return
+                    y1++
+                    d += dx
+                    if d > dy {
+                        internal_plotx--
+                        d -= dy
+                    }
+                }
+            }
+        }
+    }
+
+    sub circle(uword xcenter, ubyte ycenter, ubyte radius) {
+        ; Midpoint algorithm
+        ubyte @zp ploty
+        ubyte @zp xx = radius
+        ubyte @zp yy = 0
+        byte @zp decisionOver2 = 1-xx as byte
+
+        while xx>=yy {
+            internal_plotx = xcenter + xx
+            ploty = ycenter + yy
+            internal_plot(ploty)
+            internal_plotx = xcenter - xx
+            internal_plot(ploty)
+            internal_plotx = xcenter + xx
+            ploty = ycenter - yy
+            internal_plot(ploty)
+            internal_plotx = xcenter - xx
+            internal_plot(ploty)
+            internal_plotx = xcenter + yy
+            ploty = ycenter + xx
+            internal_plot(ploty)
+            internal_plotx = xcenter - yy
+            internal_plot(ploty)
+            internal_plotx = xcenter + yy
+            ploty = ycenter - xx
+            internal_plot(ploty)
+            internal_plotx = xcenter - yy
+            internal_plot(ploty)
+            yy++
+            if decisionOver2<=0
+                decisionOver2 += 2*yy+1
+            else {
+                xx--
+                decisionOver2 += 2*(yy-xx)+1
+            }
+        }
+    }
+
+    sub disc(uword xcenter, ubyte ycenter, ubyte radius) {
+        ; Midpoint algorithm, filled
+        ubyte xx = radius
+        ubyte yy = 0
+        byte decisionOver2 = 1-xx as byte
+
+        while xx>=yy {
+            ubyte ycenter_plus_yy = ycenter + yy
+            ubyte ycenter_min_yy = ycenter - yy
+            ubyte ycenter_plus_xx = ycenter + xx
+            ubyte ycenter_min_xx = ycenter - xx
+
+            for internal_plotx in xcenter to xcenter+xx {
+                internal_plot(ycenter_plus_yy)
+                internal_plot(ycenter_min_yy)
+            }
+            for internal_plotx in xcenter-xx to xcenter-1 {
+                internal_plot(ycenter_plus_yy)
+                internal_plot(ycenter_min_yy)
+            }
+            for internal_plotx in xcenter to xcenter+yy {
+                internal_plot(ycenter_plus_xx)
+                internal_plot(ycenter_min_xx)
+            }
+            for internal_plotx in xcenter-yy to xcenter {
+                internal_plot(ycenter_plus_xx)
+                internal_plot(ycenter_min_xx)
+            }
+            yy++
+            if decisionOver2<=0
+                decisionOver2 += 2*yy+1
+            else {
+                xx--
+                decisionOver2 += 2*(yy-xx)+1
+            }
+        }
+    }
+
+
+; here is the non-asm code for the plot routine below:
+;    sub plot_nonasm(uword px, ubyte py) {
+;        ubyte[] ormask = [128, 64, 32, 16, 8, 4, 2, 1]
+;        uword addr = BITMAP_ADDRESS + 320*(py>>3) + (py & 7) + (px & %0000000111111000)
+;        @(addr) |= ormask[lsb(px) & 7]
+;    }
+
+    asmsub  plot(uword plotx @XY, ubyte ploty @A) clobbers (A, X, Y) {
+        %asm {{
+            stx  internal_plotx
+            sty  internal_plotx+1
+            jmp  internal_plot
+        }}
+    }
+
+    ; 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()
+
+    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 {{
+        tay
+        lda  internal_plotx+1
+        sta  P8ZP_SCRATCH_W2+1
+        lsr  a            ; 0
+        sta  P8ZP_SCRATCH_W2
+        lda  internal_plotx
+        pha
+        and  #7
+        tax
+
+        lda  _y_lookup_lo,y
+        clc
+        adc  P8ZP_SCRATCH_W2
+        sta  P8ZP_SCRATCH_W2
+        lda  _y_lookup_hi,y
+        adc  P8ZP_SCRATCH_W2+1
+        sta  P8ZP_SCRATCH_W2+1
+
+        pla     ; internal_plotx
+        and  #%11111000
+        tay
+        lda  (P8ZP_SCRATCH_W2),y
+        ora  _ormask,x
+        sta  (P8ZP_SCRATCH_W2),y
+        rts
+
+_ormask     .byte 128, 64, 32, 16, 8, 4, 2, 1
+
+; note: this can be even faster if we also have a 256 byte x-lookup table, but hey.
+; see http://codebase64.org/doku.php?id=base:various_techniques_to_calculate_adresses_fast_common_screen_formats_for_pixel_graphics
+; the y lookup tables encodes this formula:  BITMAP_ADDRESS + 320*(py>>3) + (py & 7)    (y from 0..199)
+; We use the 64tass syntax for range expressions to calculate this table on assembly time.
+
+_plot_y_values := $2000 + 320*(range(200)>>3) + (range(200) & 7)
+
+_y_lookup_lo    .byte  <_plot_y_values
+_y_lookup_hi    .byte  >_plot_y_values
+
+        }}
+    }
+
+}
+
+

compiler/res/prog8lib/c64/syslib.p8

@@ -0,0 +1,448 @@
+; 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
+
+%target c64
+
+c64 {
+        &ubyte  TIME_HI         = $a0       ; software jiffy clock, hi byte
+        &ubyte  TIME_MID        = $a1       ;  .. mid byte
+        &ubyte  TIME_LO         = $a2       ;    .. lo byte. Updated by IRQ every 1/60 sec
+        &ubyte  STATUS          = $90       ; kernel status variable for I/O
+        &ubyte  STKEY           = $91       ; various keyboard statuses (updated by IRQ)
+        &ubyte  SFDX            = $cb       ; current key pressed (matrix value) (updated by IRQ)
+
+        &ubyte  COLOR           = $0286     ; cursor color
+        &ubyte  HIBASE          = $0288     ; screen base address / 256 (hi-byte of screen memory address)
+        &uword  CINV            = $0314     ; IRQ vector
+        &uword  NMI_VEC         = $FFFA     ; 6502 nmi vector, determined by the kernal if banked in
+        &uword  RESET_VEC       = $FFFC     ; 6502 reset vector, determined by the kernal if banked in
+        &uword  IRQ_VEC         = $FFFE     ; 6502 interrupt vector, determined by the kernal if banked in
+
+        ; the default addresses for the character screen chars and colors
+        const  uword  Screen    = $0400     ; to have this as an array[40*25] the compiler would have to support array size > 255
+        const  uword  Colors    = $d800     ; to have this as an array[40*25] the compiler would have to support array size > 255
+
+        ; the default locations of the 8 sprite pointers (store address of sprite / 64)
+        &ubyte  SPRPTR0         = 2040
+        &ubyte  SPRPTR1         = 2041
+        &ubyte  SPRPTR2         = 2042
+        &ubyte  SPRPTR3         = 2043
+        &ubyte  SPRPTR4         = 2044
+        &ubyte  SPRPTR5         = 2045
+        &ubyte  SPRPTR6         = 2046
+        &ubyte  SPRPTR7         = 2047
+        &ubyte[8]  SPRPTR       = 2040      ; the 8 sprite pointers as an array.
+
+
+; ---- VIC-II 6567/6569/856x registers ----
+
+        &ubyte  SP0X            = $d000
+        &ubyte  SP0Y            = $d001
+        &ubyte  SP1X            = $d002
+        &ubyte  SP1Y            = $d003
+        &ubyte  SP2X            = $d004
+        &ubyte  SP2Y            = $d005
+        &ubyte  SP3X            = $d006
+        &ubyte  SP3Y            = $d007
+        &ubyte  SP4X            = $d008
+        &ubyte  SP4Y            = $d009
+        &ubyte  SP5X            = $d00a
+        &ubyte  SP5Y            = $d00b
+        &ubyte  SP6X            = $d00c
+        &ubyte  SP6Y            = $d00d
+        &ubyte  SP7X            = $d00e
+        &ubyte  SP7Y            = $d00f
+        &ubyte[16]  SPXY        = $d000        ; the 8 sprite X and Y registers as an array.
+        &uword[8]  SPXYW        = $d000        ; the 8 sprite X and Y registers as a combined xy word array.
+
+        &ubyte  MSIGX           = $d010
+        &ubyte  SCROLY          = $d011
+        &ubyte  RASTER          = $d012
+        &ubyte  LPENX           = $d013
+        &ubyte  LPENY           = $d014
+        &ubyte  SPENA           = $d015
+        &ubyte  SCROLX          = $d016
+        &ubyte  YXPAND          = $d017
+        &ubyte  VMCSB           = $d018
+        &ubyte  VICIRQ          = $d019
+        &ubyte  IREQMASK        = $d01a
+        &ubyte  SPBGPR          = $d01b
+        &ubyte  SPMC            = $d01c
+        &ubyte  XXPAND          = $d01d
+        &ubyte  SPSPCL          = $d01e
+        &ubyte  SPBGCL          = $d01f
+
+        &ubyte  EXTCOL          = $d020        ; border color
+        &ubyte  BGCOL0          = $d021        ; screen color
+        &ubyte  BGCOL1          = $d022
+        &ubyte  BGCOL2          = $d023
+        &ubyte  BGCOL4          = $d024
+        &ubyte  SPMC0           = $d025
+        &ubyte  SPMC1           = $d026
+        &ubyte  SP0COL          = $d027
+        &ubyte  SP1COL          = $d028
+        &ubyte  SP2COL          = $d029
+        &ubyte  SP3COL          = $d02a
+        &ubyte  SP4COL          = $d02b
+        &ubyte  SP5COL          = $d02c
+        &ubyte  SP6COL          = $d02d
+        &ubyte  SP7COL          = $d02e
+        &ubyte[8]  SPCOL        = $d027
+
+
+; ---- end of VIC-II registers ----
+
+; ---- CIA 6526 1 & 2 registers ----
+
+        &ubyte  CIA1PRA         = $DC00        ; CIA 1 DRA, keyboard column drive (and joystick control port #2)
+        &ubyte  CIA1PRB         = $DC01        ; CIA 1 DRB, keyboard row port (and joystick control port #1)
+        &ubyte  CIA1DDRA        = $DC02        ; CIA 1 DDRA, keyboard column
+        &ubyte  CIA1DDRB        = $DC03        ; CIA 1 DDRB, keyboard row
+        &ubyte  CIA1TAL         = $DC04        ; CIA 1 timer A low byte
+        &ubyte  CIA1TAH         = $DC05        ; CIA 1 timer A high byte
+        &ubyte  CIA1TBL         = $DC06        ; CIA 1 timer B low byte
+        &ubyte  CIA1TBH         = $DC07        ; CIA 1 timer B high byte
+        &ubyte  CIA1TOD10       = $DC08        ; time of day, 1/10 sec.
+        &ubyte  CIA1TODSEC      = $DC09        ; time of day, seconds
+        &ubyte  CIA1TODMMIN     = $DC0A        ; time of day, minutes
+        &ubyte  CIA1TODHR       = $DC0B        ; time of day, hours
+        &ubyte  CIA1SDR         = $DC0C        ; Serial Data Register
+        &ubyte  CIA1ICR         = $DC0D
+        &ubyte  CIA1CRA         = $DC0E
+        &ubyte  CIA1CRB         = $DC0F
+
+        &ubyte  CIA2PRA         = $DD00        ; CIA 2 DRA, serial port and video address
+        &ubyte  CIA2PRB         = $DD01        ; CIA 2 DRB, RS232 port / USERPORT
+        &ubyte  CIA2DDRA        = $DD02        ; CIA 2 DDRA, serial port and video address
+        &ubyte  CIA2DDRB        = $DD03        ; CIA 2 DDRB, RS232 port / USERPORT
+        &ubyte  CIA2TAL         = $DD04        ; CIA 2 timer A low byte
+        &ubyte  CIA2TAH         = $DD05        ; CIA 2 timer A high byte
+        &ubyte  CIA2TBL         = $DD06        ; CIA 2 timer B low byte
+        &ubyte  CIA2TBH         = $DD07        ; CIA 2 timer B high byte
+        &ubyte  CIA2TOD10       = $DD08        ; time of day, 1/10 sec.
+        &ubyte  CIA2TODSEC      = $DD09        ; time of day, seconds
+        &ubyte  CIA2TODMIN      = $DD0A        ; time of day, minutes
+        &ubyte  CIA2TODHR       = $DD0B        ; time of day, hours
+        &ubyte  CIA2SDR         = $DD0C        ; Serial Data Register
+        &ubyte  CIA2ICR         = $DD0D
+        &ubyte  CIA2CRA         = $DD0E
+        &ubyte  CIA2CRB         = $DD0F
+
+; ---- end of CIA registers ----
+
+; ---- SID 6581/8580 registers ----
+
+        &ubyte  FREQLO1         = $D400        ; channel 1 freq lo
+        &ubyte  FREQHI1         = $D401        ; channel 1 freq hi
+        &uword  FREQ1           = $D400        ; channel 1 freq (word)
+        &ubyte  PWLO1           = $D402        ; channel 1 pulse width lo (7-0)
+        &ubyte  PWHI1           = $D403        ; channel 1 pulse width hi (11-8)
+        &uword  PW1             = $D402        ; channel 1 pulse width (word)
+        &ubyte  CR1             = $D404        ; channel 1 voice control register
+        &ubyte  AD1             = $D405        ; channel 1 attack & decay
+        &ubyte  SR1             = $D406        ; channel 1 sustain & release
+        &ubyte  FREQLO2         = $D407        ; channel 2 freq lo
+        &ubyte  FREQHI2         = $D408        ; channel 2 freq hi
+        &uword  FREQ2           = $D407        ; channel 2 freq (word)
+        &ubyte  PWLO2           = $D409        ; channel 2 pulse width lo (7-0)
+        &ubyte  PWHI2           = $D40A        ; channel 2 pulse width hi (11-8)
+        &uword  PW2             = $D409        ; channel 2 pulse width (word)
+        &ubyte  CR2             = $D40B        ; channel 2 voice control register
+        &ubyte  AD2             = $D40C        ; channel 2 attack & decay
+        &ubyte  SR2             = $D40D        ; channel 2 sustain & release
+        &ubyte  FREQLO3         = $D40E        ; channel 3 freq lo
+        &ubyte  FREQHI3         = $D40F        ; channel 3 freq hi
+        &uword  FREQ3           = $D40E        ; channel 3 freq (word)
+        &ubyte  PWLO3           = $D410        ; channel 3 pulse width lo (7-0)
+        &ubyte  PWHI3           = $D411        ; channel 3 pulse width hi (11-8)
+        &uword  PW3             = $D410        ; channel 3 pulse width (word)
+        &ubyte  CR3             = $D412        ; channel 3 voice control register
+        &ubyte  AD3             = $D413        ; channel 3 attack & decay
+        &ubyte  SR3             = $D414        ; channel 3 sustain & release
+        &ubyte  FCLO            = $D415        ; filter cutoff lo (2-0)
+        &ubyte  FCHI            = $D416        ; filter cutoff hi (10-3)
+        &uword  FC              = $D415        ; filter cutoff (word)
+        &ubyte  RESFILT         = $D417        ; filter resonance and routing
+        &ubyte  MVOL            = $D418        ; filter mode and main volume control
+        &ubyte  POTX            = $D419        ; potentiometer X
+        &ubyte  POTY            = $D41A        ; potentiometer Y
+        &ubyte  OSC3            = $D41B        ; channel 3 oscillator value read
+        &ubyte  ENV3            = $D41C        ; channel 3 envelope value read
+
+; ---- end of SID registers ----
+
+
+; ---- C64 ROM kernal routines ----
+
+romsub $AB1E = STROUT(uword strptr @ AY) clobbers(A, X, Y)      ; print null-terminated string (use c64scr.print instead)
+romsub $E544 = CLEARSCR() clobbers(A,X,Y)                       ; clear the screen
+romsub $E566 = HOMECRSR() clobbers(A,X,Y)                       ; cursor to top left of screen
+romsub $EA31 = IRQDFRT() clobbers(A,X,Y)                        ; default IRQ routine
+romsub $EA81 = IRQDFEND() clobbers(A,X,Y)                       ; default IRQ end/cleanup
+romsub $FF81 = CINT() clobbers(A,X,Y)                           ; (alias: SCINIT) initialize screen editor and video chip
+romsub $FF84 = IOINIT() clobbers(A, X)                          ; initialize I/O devices (CIA, SID, IRQ)
+romsub $FF87 = RAMTAS() clobbers(A,X,Y)                         ; initialize RAM, tape buffer, screen
+romsub $FF8A = RESTOR() clobbers(A,X,Y)                         ; restore default I/O vectors
+romsub $FF8D = VECTOR(uword userptr @ XY, ubyte dir @ Pc) clobbers(A,Y)     ; read/set I/O vector table
+romsub $FF90 = SETMSG(ubyte value @ A)                          ; set Kernal message control flag
+romsub $FF93 = SECOND(ubyte address @ A) clobbers(A)            ; (alias: LSTNSA) send secondary address after LISTEN
+romsub $FF96 = TKSA(ubyte address @ A) clobbers(A)              ; (alias: TALKSA) send secondary address after TALK
+romsub $FF99 = MEMTOP(uword address @ XY, ubyte dir @ Pc) -> uword @ XY     ; read/set top of memory  pointer
+romsub $FF9C = MEMBOT(uword address @ XY, ubyte dir @ Pc) -> uword @ XY     ; read/set bottom of memory  pointer
+romsub $FF9F = SCNKEY() clobbers(A,X,Y)                         ; scan the keyboard
+romsub $FFA2 = SETTMO(ubyte timeout @ A)                        ; set time-out flag for IEEE bus
+romsub $FFA5 = ACPTR() -> ubyte @ A                             ; (alias: IECIN) input byte from serial bus
+romsub $FFA8 = CIOUT(ubyte databyte @ A)                        ; (alias: IECOUT) output byte to serial bus
+romsub $FFAB = UNTLK() clobbers(A)                              ; command serial bus device to UNTALK
+romsub $FFAE = UNLSN() clobbers(A)                              ; command serial bus device to UNLISTEN
+romsub $FFB1 = LISTEN(ubyte device @ A) clobbers(A)             ; command serial bus device to LISTEN
+romsub $FFB4 = TALK(ubyte device @ A) clobbers(A)               ; command serial bus device to TALK
+romsub $FFB7 = READST() -> ubyte @ A                            ; read I/O status word
+romsub $FFBA = SETLFS(ubyte logical @ A, ubyte device @ X, ubyte address @ Y)   ; set logical file parameters
+romsub $FFBD = SETNAM(ubyte namelen @ A, str filename @ XY)     ; set filename parameters
+romsub $FFC0 = OPEN() clobbers(X,Y) -> ubyte @Pc, ubyte @A      ; (via 794 ($31A)) open a logical file
+romsub $FFC3 = CLOSE(ubyte logical @ A) clobbers(A,X,Y)         ; (via 796 ($31C)) close a logical file
+romsub $FFC6 = CHKIN(ubyte logical @ X) clobbers(A,X) -> ubyte @Pc    ; (via 798 ($31E)) define an input channel
+romsub $FFC9 = CHKOUT(ubyte logical @ X) clobbers(A,X)          ; (via 800 ($320)) define an output channel
+romsub $FFCC = CLRCHN() clobbers(A,X)                           ; (via 802 ($322)) restore default devices
+romsub $FFCF = CHRIN() clobbers(X, Y) -> ubyte @ A   ; (via 804 ($324)) input a character (for keyboard, read a whole line from the screen) A=byte read.
+romsub $FFD2 = CHROUT(ubyte char @ A)                           ; (via 806 ($326)) output a character
+romsub $FFD5 = LOAD(ubyte verify @ A, uword address @ XY) -> ubyte @Pc, ubyte @ A, ubyte @ X, ubyte @ Y     ; (via 816 ($330)) load from device
+romsub $FFD8 = SAVE(ubyte zp_startaddr @ A, uword endaddr @ XY) -> ubyte @ Pc, ubyte @ A                    ; (via 818 ($332)) save to a device
+romsub $FFDB = SETTIM(ubyte low @ A, ubyte middle @ X, ubyte high @ Y)      ; set the software clock
+romsub $FFDE = RDTIM() -> ubyte @ A, ubyte @ X, ubyte @ Y       ; read the software clock
+romsub $FFE1 = STOP() clobbers(X) -> ubyte @ Pz, ubyte @ A      ; (via 808 ($328)) check the STOP key (and some others in A)
+romsub $FFE4 = GETIN() clobbers(X,Y) -> ubyte @Pc, ubyte @ A    ; (via 810 ($32A)) get a character
+romsub $FFE7 = CLALL() clobbers(A,X)                            ; (via 812 ($32C)) close all files
+romsub $FFEA = UDTIM() clobbers(A,X)                            ; update the software clock
+romsub $FFED = SCREEN() -> ubyte @ X, ubyte @ Y                 ; read number of screen rows and columns
+romsub $FFF0 = PLOT(ubyte col @ Y, ubyte row @ X, ubyte dir @ Pc) -> ubyte @ X, ubyte @ Y       ; read/set position of cursor on screen.  Use txt.plot for a 'safe' wrapper that preserves X.
+romsub $FFF3 = IOBASE() -> uword @ XY                           ; read base address of I/O devices
+
+; ---- end of C64 ROM kernal routines ----
+
+
+; ---- C64 specific system utility routines: ----
+
+asmsub  init_system()  {
+    ; Initializes the machine to a sane starting state.
+    ; Called automatically by the loader program logic.
+    ; This means that the BASIC, KERNAL and CHARGEN ROMs are banked in,
+    ; the VIC, SID and CIA chips are reset, screen is cleared, and the default IRQ is set.
+    ; Also a different color scheme is chosen to identify ourselves a little.
+    ; Uppercase charset is activated, and all three registers set to 0, status flags cleared.
+    %asm {{
+        sei
+        cld
+        lda  #%00101111
+        sta  $00
+        lda  #%00100111
+        sta  $01
+        jsr  c64.IOINIT
+        jsr  c64.RESTOR
+        jsr  c64.CINT
+        lda  #6
+        sta  c64.EXTCOL
+        lda  #7
+        sta  c64.COLOR
+        lda  #0
+        sta  c64.BGCOL0
+        jsr  disable_runstop_and_charsetswitch
+        clc
+        clv
+        cli
+        rts
+    }}
+}
+
+asmsub  reset_system()  {
+    ; Soft-reset the system back to Basic prompt.
+    %asm {{
+        sei
+        lda  #14
+        sta  $01        ; bank the kernal in
+        jmp  (c64.RESET_VEC)
+    }}
+}
+
+asmsub  disable_runstop_and_charsetswitch() {
+    %asm {{
+        lda  #$80
+        sta  657    ; disable charset switching
+        lda  #239
+        sta  808    ; disable run/stop key
+        rts
+    }}
+}
+
+asmsub  set_irqvec_excl() clobbers(A)  {
+	%asm {{
+		sei
+		lda  #<_irq_handler
+		sta  c64.CINV
+		lda  #>_irq_handler
+		sta  c64.CINV+1
+		cli
+		rts
+_irq_handler	jsr  set_irqvec._irq_handler_init
+		jsr  irq.irq
+		jsr  set_irqvec._irq_handler_end
+		lda  #$ff
+		sta  c64.VICIRQ			; acknowledge raster irq
+		lda  c64.CIA1ICR		; acknowledge CIA1 interrupt
+		jmp  c64.IRQDFEND		; end irq processing - don't call kernel
+	}}
+}
+
+asmsub  set_irqvec() clobbers(A)  {
+	%asm {{
+		sei
+		lda  #<_irq_handler
+		sta  c64.CINV
+		lda  #>_irq_handler
+		sta  c64.CINV+1
+		cli
+		rts
+_irq_handler    jsr  _irq_handler_init
+		jsr  irq.irq
+		jsr  _irq_handler_end
+		jmp  c64.IRQDFRT		; continue with normal kernel irq routine
+
+_irq_handler_init
+		; save all zp scratch registers and the X register as these might be clobbered by the irq routine
+		stx  IRQ_X_REG
+		lda  P8ZP_SCRATCH_B1
+		sta  IRQ_SCRATCH_ZPB1
+		lda  P8ZP_SCRATCH_REG
+		sta  IRQ_SCRATCH_ZPREG
+		lda  P8ZP_SCRATCH_W1
+		sta  IRQ_SCRATCH_ZPWORD1
+		lda  P8ZP_SCRATCH_W1+1
+		sta  IRQ_SCRATCH_ZPWORD1+1
+		lda  P8ZP_SCRATCH_W2
+		sta  IRQ_SCRATCH_ZPWORD2
+		lda  P8ZP_SCRATCH_W2+1
+		sta  IRQ_SCRATCH_ZPWORD2+1
+		; stack protector; make sure we don't clobber the top of the evaluation stack
+		dex
+		dex
+		dex
+		dex
+		dex
+		dex
+		cld
+		rts
+
+_irq_handler_end
+		; restore all zp scratch registers and the X register
+		lda  IRQ_SCRATCH_ZPB1
+		sta  P8ZP_SCRATCH_B1
+		lda  IRQ_SCRATCH_ZPREG
+		sta  P8ZP_SCRATCH_REG
+		lda  IRQ_SCRATCH_ZPWORD1
+		sta  P8ZP_SCRATCH_W1
+		lda  IRQ_SCRATCH_ZPWORD1+1
+		sta  P8ZP_SCRATCH_W1+1
+		lda  IRQ_SCRATCH_ZPWORD2
+		sta  P8ZP_SCRATCH_W2
+		lda  IRQ_SCRATCH_ZPWORD2+1
+		sta  P8ZP_SCRATCH_W2+1
+		ldx  IRQ_X_REG
+		rts
+
+IRQ_X_REG		.byte  0
+IRQ_SCRATCH_ZPB1	.byte  0
+IRQ_SCRATCH_ZPREG	.byte  0
+IRQ_SCRATCH_ZPWORD1	.word  0
+IRQ_SCRATCH_ZPWORD2	.word  0
+
+		}}
+}
+
+asmsub  restore_irqvec() {
+	%asm {{
+		sei
+		lda  #<c64.IRQDFRT
+		sta  c64.CINV
+		lda  #>c64.IRQDFRT
+		sta  c64.CINV+1
+		lda  #0
+		sta  c64.IREQMASK	; disable raster irq
+		lda  #%10000001
+		sta  c64.CIA1ICR	; restore CIA1 irq
+		cli
+		rts
+	}}
+}
+
+asmsub  set_rasterirq(uword rasterpos @ AY) clobbers(A) {
+	%asm {{
+		sei
+		jsr  _setup_raster_irq
+		lda  #<_raster_irq_handler
+		sta  c64.CINV
+		lda  #>_raster_irq_handler
+		sta  c64.CINV+1
+		cli
+		rts
+
+_raster_irq_handler
+		jsr  set_irqvec._irq_handler_init
+		jsr  irq.irq
+		jsr  set_irqvec._irq_handler_end
+		lda  #$ff
+		sta  c64.VICIRQ			; acknowledge raster irq
+		jmp  c64.IRQDFRT
+
+_setup_raster_irq
+		pha
+		lda  #%01111111
+		sta  c64.CIA1ICR    ; "switch off" interrupts signals from cia-1
+		sta  c64.CIA2ICR    ; "switch off" interrupts signals from cia-2
+		and  c64.SCROLY
+		sta  c64.SCROLY     ; clear most significant bit of raster position
+		lda  c64.CIA1ICR    ; ack previous irq
+		lda  c64.CIA2ICR    ; ack previous irq
+		pla
+		sta  c64.RASTER     ; set the raster line number where interrupt should occur
+		cpy  #0
+		beq  +
+		lda  c64.SCROLY
+		ora  #%10000000
+		sta  c64.SCROLY     ; set most significant bit of raster position
++		lda  #%00000001
+		sta  c64.IREQMASK   ;enable raster interrupt signals from vic
+		rts
+	}}
+}
+
+asmsub  set_rasterirq_excl(uword rasterpos @ AY) clobbers(A) {
+	%asm {{
+		sei
+		jsr  set_rasterirq._setup_raster_irq
+		lda  #<_raster_irq_handler
+		sta  c64.CINV
+		lda  #>_raster_irq_handler
+		sta  c64.CINV+1
+		cli
+		rts
+
+_raster_irq_handler
+		jsr  set_irqvec._irq_handler_init
+		jsr  irq.irq
+		jsr  set_irqvec._irq_handler_end
+		lda  #$ff
+		sta  c64.VICIRQ			; acknowledge raster irq
+		jmp  c64.IRQDFEND		; end irq processing - don't call kernel
+
+	}}
+}
+
+; ---- end of C64 specific system utility routines ----
+
+
+}

compiler/res/prog8lib/c64/textio.p8

@@ -0,0 +1,587 @@
+; 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
+
+%target c64
+%import syslib
+%import conv
+
+
+txt {
+
+const ubyte DEFAULT_WIDTH = 40
+const ubyte DEFAULT_HEIGHT = 25
+
+
+sub  clear_screen() {
+    clear_screenchars(' ')
+}
+
+asmsub  fill_screen (ubyte char @ A, ubyte color @ Y) clobbers(A)  {
+	; ---- fill the character screen with the given fill character and character color.
+	;      (assumes screen and color matrix are at their default addresses)
+
+	%asm {{
+		pha
+		tya
+		jsr  clear_screencolors
+		pla
+		jsr  clear_screenchars
+		rts
+        }}
+
+}
+
+asmsub  clear_screenchars (ubyte char @ A) clobbers(Y)  {
+	; ---- clear the character screen with the given fill character (leaves colors)
+	;      (assumes screen matrix is at the default address)
+	%asm {{
+		ldy  #0
+_loop		sta  c64.Screen,y
+		sta  c64.Screen+$0100,y
+		sta  c64.Screen+$0200,y
+		sta  c64.Screen+$02e8,y
+		iny
+		bne  _loop
+		rts
+        }}
+}
+
+asmsub  clear_screencolors (ubyte color @ A) clobbers(Y)  {
+	; ---- clear the character screen colors with the given color (leaves characters).
+	;      (assumes color matrix is at the default address)
+	%asm {{
+		ldy  #0
+_loop		sta  c64.Colors,y
+		sta  c64.Colors+$0100,y
+		sta  c64.Colors+$0200,y
+		sta  c64.Colors+$02e8,y
+		iny
+		bne  _loop
+		rts
+        }}
+}
+
+sub color (ubyte txtcol) {
+    c64.COLOR = txtcol
+}
+
+sub lowercase() {
+    c64.VMCSB |= 2
+}
+
+sub uppercase() {
+    c64.VMCSB &= ~2
+}
+
+asmsub  scroll_left  (ubyte alsocolors @ Pc) clobbers(A, Y)  {
+	; ---- scroll the whole screen 1 character to the left
+	;      contents of the rightmost column are unchanged, you should clear/refill this yourself
+	;      Carry flag determines if screen color data must be scrolled too
+
+	%asm {{
+		stx  P8ZP_SCRATCH_REG
+		bcs  +
+		jmp  _scroll_screen
+
++               ; scroll the color memory
+		ldx  #0
+		ldy  #38
+-
+	.for row=0, row<=24, row+=1
+		lda  c64.Colors + 40*row + 1,x
+		sta  c64.Colors + 40*row,x
+	.next
+		inx
+		dey
+		bpl  -
+
+_scroll_screen  ; scroll the screen memory
+		ldx  #0
+		ldy  #38
+-
+	.for row=0, row<=24, row+=1
+		lda  c64.Screen + 40*row + 1,x
+		sta  c64.Screen + 40*row,x
+	.next
+		inx
+		dey
+		bpl  -
+
+		ldx  P8ZP_SCRATCH_REG
+		rts
+	}}
+}
+
+asmsub  scroll_right  (ubyte alsocolors @ Pc) clobbers(A)  {
+	; ---- scroll the whole screen 1 character to the right
+	;      contents of the leftmost column are unchanged, you should clear/refill this yourself
+	;      Carry flag determines if screen color data must be scrolled too
+	%asm {{
+		stx  P8ZP_SCRATCH_REG
+		bcs  +
+		jmp  _scroll_screen
+
++               ; scroll the color memory
+		ldx  #38
+-
+	.for row=0, row<=24, row+=1
+		lda  c64.Colors + 40*row + 0,x
+		sta  c64.Colors + 40*row + 1,x
+	.next
+		dex
+		bpl  -
+
+_scroll_screen  ; scroll the screen memory
+		ldx  #38
+-
+	.for row=0, row<=24, row+=1
+		lda  c64.Screen + 40*row + 0,x
+		sta  c64.Screen + 40*row + 1,x
+	.next
+		dex
+		bpl  -
+
+		ldx  P8ZP_SCRATCH_REG
+		rts
+	}}
+}
+
+asmsub  scroll_up  (ubyte alsocolors @ Pc) clobbers(A)  {
+	; ---- scroll the whole screen 1 character up
+	;      contents of the bottom row are unchanged, you should refill/clear this yourself
+	;      Carry flag determines if screen color data must be scrolled too
+	%asm {{
+		stx  P8ZP_SCRATCH_REG
+		bcs  +
+		jmp  _scroll_screen
+
++               ; scroll the color memory
+		ldx #39
+-
+	.for row=1, row<=24, row+=1
+		lda  c64.Colors + 40*row,x
+		sta  c64.Colors + 40*(row-1),x
+	.next
+		dex
+		bpl  -
+
+_scroll_screen  ; scroll the screen memory
+		ldx #39
+-
+	.for row=1, row<=24, row+=1
+		lda  c64.Screen + 40*row,x
+		sta  c64.Screen + 40*(row-1),x
+	.next
+		dex
+		bpl  -
+
+		ldx  P8ZP_SCRATCH_REG
+		rts
+	}}
+}
+
+asmsub  scroll_down  (ubyte alsocolors @ Pc) clobbers(A)  {
+	; ---- scroll the whole screen 1 character down
+	;      contents of the top row are unchanged, you should refill/clear this yourself
+	;      Carry flag determines if screen color data must be scrolled too
+	%asm {{
+		stx  P8ZP_SCRATCH_REG
+		bcs  +
+		jmp  _scroll_screen
+
++               ; scroll the color memory
+		ldx #39
+-
+	.for row=23, row>=0, row-=1
+		lda  c64.Colors + 40*row,x
+		sta  c64.Colors + 40*(row+1),x
+	.next
+		dex
+		bpl  -
+
+_scroll_screen  ; scroll the screen memory
+		ldx #39
+-
+	.for row=23, row>=0, row-=1
+		lda  c64.Screen + 40*row,x
+		sta  c64.Screen + 40*(row+1),x
+	.next
+		dex
+		bpl  -
+
+		ldx  P8ZP_SCRATCH_REG
+		rts
+	}}
+}
+
+romsub $FFD2 = chrout(ubyte char @ A)    ; for consistency. You can also use c64.CHROUT directly ofcourse.
+
+asmsub  print (str text @ AY) clobbers(A,Y)  {
+	; ---- print null terminated string from A/Y
+	; note: the compiler contains an optimization that will replace
+	;       a call to this subroutine with a string argument of just one char,
+	;       by just one call to c64.CHROUT of that single char.
+	%asm {{
+		sta  P8ZP_SCRATCH_B1
+		sty  P8ZP_SCRATCH_REG
+		ldy  #0
+-		lda  (P8ZP_SCRATCH_B1),y
+		beq  +
+		jsr  c64.CHROUT
+		iny
+		bne  -
++		rts
+	}}
+}
+
+asmsub  print_ub0  (ubyte value @ A) clobbers(A,Y)  {
+	; ---- print the ubyte in A in decimal form, with left padding 0s (3 positions total)
+	%asm {{
+		stx  P8ZP_SCRATCH_REG
+		jsr  conv.ubyte2decimal
+		pha
+		tya
+		jsr  c64.CHROUT
+		pla
+		jsr  c64.CHROUT
+		txa
+		jsr  c64.CHROUT
+		ldx  P8ZP_SCRATCH_REG
+		rts
+	}}
+}
+
+asmsub  print_ub  (ubyte value @ A) clobbers(A,Y)  {
+	; ---- print the ubyte in A in decimal form, without left padding 0s
+	%asm {{
+		stx  P8ZP_SCRATCH_REG
+		jsr  conv.ubyte2decimal
+_print_byte_digits
+		pha
+		cpy  #'0'
+		beq  +
+		tya
+		jsr  c64.CHROUT
+		pla
+		jsr  c64.CHROUT
+		jmp  _ones
++       pla
+        cmp  #'0'
+        beq  _ones
+        jsr  c64.CHROUT
+_ones   txa
+		jsr  c64.CHROUT
+		ldx  P8ZP_SCRATCH_REG
+		rts
+	}}
+}
+
+asmsub  print_b  (byte value @ A) clobbers(A,Y)  {
+	; ---- print the byte in A in decimal form, without left padding 0s
+	%asm {{
+		stx  P8ZP_SCRATCH_REG
+		pha
+		cmp  #0
+		bpl  +
+		lda  #'-'
+		jsr  c64.CHROUT
++		pla
+		jsr  conv.byte2decimal
+		jmp  print_ub._print_byte_digits
+	}}
+}
+
+asmsub  print_ubhex  (ubyte value @ A, ubyte prefix @ Pc) clobbers(A,Y)  {
+	; ---- print the ubyte in A in hex form (if Carry is set, a radix prefix '$' is printed as well)
+	%asm {{
+		stx  P8ZP_SCRATCH_REG
+		bcc  +
+		pha
+		lda  #'$'
+		jsr  c64.CHROUT
+		pla
++		jsr  conv.ubyte2hex
+		jsr  c64.CHROUT
+		tya
+		jsr  c64.CHROUT
+		ldx  P8ZP_SCRATCH_REG
+		rts
+	}}
+}
+
+asmsub  print_ubbin  (ubyte value @ A, ubyte prefix @ Pc) clobbers(A,Y)  {
+	; ---- print the ubyte in A in binary form (if Carry is set, a radix prefix '%' is printed as well)
+	%asm {{
+		stx  P8ZP_SCRATCH_REG
+		sta  P8ZP_SCRATCH_B1
+		bcc  +
+		lda  #'%'
+		jsr  c64.CHROUT
++		ldy  #8
+-		lda  #'0'
+		asl  P8ZP_SCRATCH_B1
+		bcc  +
+		lda  #'1'
++		jsr  c64.CHROUT
+		dey
+		bne  -
+		ldx  P8ZP_SCRATCH_REG
+		rts
+	}}
+}
+
+asmsub  print_uwbin  (uword value @ AY, ubyte prefix @ Pc) clobbers(A,Y)  {
+	; ---- print the uword in A/Y in binary form (if Carry is set, a radix prefix '%' is printed as well)
+	%asm {{
+		pha
+		tya
+		jsr  print_ubbin
+		pla
+		clc
+		jmp  print_ubbin
+	}}
+}
+
+asmsub  print_uwhex  (uword value @ AY, ubyte prefix @ Pc) clobbers(A,Y)  {
+	; ---- print the uword in A/Y in hexadecimal form (4 digits)
+	;      (if Carry is set, a radix prefix '$' is printed as well)
+	%asm {{
+		pha
+		tya
+		jsr  print_ubhex
+		pla
+		clc
+		jmp  print_ubhex
+	}}
+}
+
+asmsub  print_uw0  (uword value @ AY) clobbers(A,Y)  {
+	; ---- print the uword in A/Y in decimal form, with left padding 0s (5 positions total)
+	%asm {{
+	    stx  P8ZP_SCRATCH_REG
+		jsr  conv.uword2decimal
+		ldy  #0
+-		lda  conv.uword2decimal.decTenThousands,y
+        beq  +
+		jsr  c64.CHROUT
+		iny
+		bne  -
++		ldx  P8ZP_SCRATCH_REG
+		rts
+	}}
+}
+
+asmsub  print_uw  (uword value @ AY) clobbers(A,Y)  {
+	; ---- print the uword in A/Y in decimal form, without left padding 0s
+	%asm {{
+	    stx  P8ZP_SCRATCH_REG
+		jsr  conv.uword2decimal
+		ldx  P8ZP_SCRATCH_REG
+		ldy  #0
+-		lda  conv.uword2decimal.decTenThousands,y
+		beq  _allzero
+		cmp  #'0'
+		bne  _gotdigit
+		iny
+		bne  -
+
+_gotdigit
+		jsr  c64.CHROUT
+		iny
+		lda  conv.uword2decimal.decTenThousands,y
+		bne  _gotdigit
+		rts
+_allzero
+        lda  #'0'
+        jmp  c64.CHROUT
+	}}
+}
+
+asmsub  print_w  (word value @ AY) clobbers(A,Y)  {
+	; ---- print the (signed) word in A/Y in decimal form, without left padding 0's
+	%asm {{
+		cpy  #0
+		bpl  +
+		pha
+		lda  #'-'
+		jsr  c64.CHROUT
+		tya
+		eor  #255
+		tay
+		pla
+		eor  #255
+		clc
+		adc  #1
+		bcc  +
+		iny
++		jmp  print_uw
+	}}
+}
+
+asmsub  input_chars  (uword buffer @ AY) clobbers(A) -> ubyte @ Y  {
+	; ---- Input a string (max. 80 chars) from the keyboard. Returns length in Y. (string is terminated with a 0 byte as well)
+	;      It assumes the keyboard is selected as I/O channel!
+
+	%asm {{
+		sta  P8ZP_SCRATCH_W1
+		sty  P8ZP_SCRATCH_W1+1
+		ldy  #0				; char counter = 0
+-		jsr  c64.CHRIN
+		cmp  #$0d			; return (ascii 13) pressed?
+		beq  +				; yes, end.
+		sta  (P8ZP_SCRATCH_W1),y	; else store char in buffer
+		iny
+		bne  -
++		lda  #0
+		sta  (P8ZP_SCRATCH_W1),y	; finish string with 0 byte
+		rts
+
+	}}
+}
+
+asmsub  setchr  (ubyte col @X, ubyte row @Y, ubyte character @A) clobbers(A, Y)  {
+	; ---- sets the character in the screen matrix at the given position
+	%asm {{
+		pha
+		tya
+		asl  a
+		tay
+		lda  _screenrows+1,y
+		sta  _mod+2
+		txa
+		clc
+		adc  _screenrows,y
+		sta  _mod+1
+		bcc  +
+		inc  _mod+2
++		pla
+_mod		sta  $ffff		; modified
+		rts
+
+_screenrows	.word  $0400 + range(0, 1000, 40)
+	}}
+}
+
+asmsub  getchr  (ubyte col @A, ubyte row @Y) clobbers(Y) -> ubyte @ A {
+	; ---- get the character in the screen matrix at the given location
+	%asm  {{
+		pha
+		tya
+		asl  a
+		tay
+		lda  setchr._screenrows+1,y
+		sta  _mod+2
+		pla
+		clc
+		adc  setchr._screenrows,y
+		sta  _mod+1
+		bcc  _mod
+		inc  _mod+2
+_mod		lda  $ffff		; modified
+		rts
+	}}
+}
+
+asmsub  setclr  (ubyte col @X, ubyte row @Y, ubyte color @A) clobbers(A, Y)  {
+	; ---- set the color in A on the screen matrix at the given position
+	%asm {{
+		pha
+		tya
+		asl  a
+		tay
+		lda  _colorrows+1,y
+		sta  _mod+2
+		txa
+		clc
+		adc  _colorrows,y
+		sta  _mod+1
+		bcc  +
+		inc  _mod+2
++		pla
+_mod		sta  $ffff		; modified
+		rts
+
+_colorrows	.word  $d800 + range(0, 1000, 40)
+	}}
+}
+
+asmsub  getclr  (ubyte col @A, ubyte row @Y) clobbers(Y) -> ubyte @ A {
+	; ---- get the color in the screen color matrix at the given location
+	%asm  {{
+		pha
+		tya
+		asl  a
+		tay
+		lda  setclr._colorrows+1,y
+		sta  _mod+2
+		pla
+		clc
+		adc  setclr._colorrows,y
+		sta  _mod+1
+		bcc  _mod
+		inc  _mod+2
+_mod		lda  $ffff		; modified
+		rts
+	}}
+}
+
+sub  setcc  (ubyte column, ubyte row, ubyte char, ubyte charcolor)  {
+	; ---- set char+color at the given position on the screen
+	%asm {{
+		lda  row
+		asl  a
+		tay
+		lda  setchr._screenrows+1,y
+		sta  _charmod+2
+		adc  #$d4
+		sta  _colormod+2
+		lda  setchr._screenrows,y
+		clc
+		adc  column
+		sta  _charmod+1
+		sta  _colormod+1
+		bcc  +
+		inc  _charmod+2
+		inc  _colormod+2
++		lda  char
+_charmod	sta  $ffff		; modified
+		lda  charcolor
+_colormod	sta  $ffff		; modified
+		rts
+	}}
+}
+
+asmsub  plot  (ubyte col @ Y, ubyte row @ A) clobbers(A) {
+	; ---- safe wrapper around PLOT kernel routine, to save the X register.
+	%asm  {{
+		stx  P8ZP_SCRATCH_REG
+		tax
+		clc
+		jsr  c64.PLOT
+		ldx  P8ZP_SCRATCH_REG
+		rts
+	}}
+}
+
+asmsub width() clobbers(X,Y) -> ubyte @A {
+    ; -- returns the text screen width (number of columns)
+    %asm {{
+        jsr  c64.SCREEN
+        txa
+        rts
+    }}
+}
+
+asmsub height() clobbers(X, Y) -> ubyte @A {
+    ; -- returns the text screen height (number of rows)
+    %asm {{
+        jsr  c64.SCREEN
+        tya
+        rts
+    }}
+}
+
+}

compiler/res/prog8lib/c64flt.p8

@@ -1,969 +0,0 @@
-; 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
-
-
-c64flt {
-	; ---- this block contains C-64 floating point related functions ----
-
-		const  float  PI	= 3.141592653589793
-		const  float  TWOPI	= 6.283185307179586
-
-
-; ---- C64 basic and kernal ROM float constants and functions ----
-
-		; note: the fac1 and fac2 are working registers and take 6 bytes each,
-		; floats in memory  (and rom) are stored in 5-byte MFLPT packed format.
-
-		; constants in five-byte "mflpt" format in the BASIC ROM
-		&float  FL_PIVAL	= $aea8  ; 3.1415926...
-		&float  FL_N32768	= $b1a5  ; -32768
-		&float  FL_FONE		= $b9bc  ; 1
-		&float  FL_SQRHLF	= $b9d6  ; SQR(2) / 2
-		&float  FL_SQRTWO	= $b9db  ; SQR(2)
-		&float  FL_NEGHLF	= $b9e0  ; -.5
-		&float  FL_LOG2		= $b9e5  ; LOG(2)
-		&float  FL_TENC		= $baf9  ; 10
-		&float  FL_NZMIL	= $bdbd  ; 1e9 (1 billion)
-		&float  FL_FHALF	= $bf11  ; .5
-		&float  FL_LOGEB2	= $bfbf  ; 1 / LOG(2)
-		&float  FL_PIHALF	= $e2e0  ; PI / 2
-		&float  FL_TWOPI	= $e2e5  ; 2 * PI
-		&float  FL_FR4		= $e2ea  ; .25
-		 float  FL_ZERO		= 0.0    ; oddly enough 0.0 isn't available in the kernel
-
-
-; note: fac1/2 might get clobbered even if not mentioned in the function's name.
-; note: for subtraction and division, the left operand is in fac2, the right operand in fac1.
-
-; checked functions below:
-asmsub	MOVFM		(uword mflpt @ AY) clobbers(A,Y)	= $bba2		; load mflpt value from memory  in A/Y into fac1
-asmsub	FREADMEM	() clobbers(A,Y)			= $bba6		; load mflpt value from memory  in $22/$23 into fac1
-asmsub	CONUPK		(uword mflpt @ AY) clobbers(A,Y)	= $ba8c		; load mflpt value from memory  in A/Y into fac2
-asmsub	FAREADMEM	() clobbers(A,Y)			= $ba90		; load mflpt value from memory  in $22/$23 into fac2
-asmsub	MOVFA		() clobbers(A,X)			= $bbfc		; copy fac2 to fac1
-asmsub	MOVAF		() clobbers(A,X)			= $bc0c		; copy fac1 to fac2  (rounded)
-asmsub	MOVEF		() clobbers(A,X)			= $bc0f		; copy fac1 to fac2
-asmsub	MOVMF		(uword mflpt @ XY) clobbers(A,Y)	= $bbd4		; store fac1 to memory  X/Y as 5-byte mflpt
-
-; fac1-> signed word in Y/A (might throw ILLEGAL QUANTITY)
-; (tip: use c64flt.FTOSWRDAY to get A/Y output; lo/hi switched to normal little endian order)
-asmsub	FTOSWORDYA	() clobbers(X) -> ubyte @ Y, ubyte @ A  = $b1aa     ; note: calls AYINT.
-
-; fac1 -> unsigned word in Y/A (might throw ILLEGAL QUANTITY) (result also in $14/15)
-; (tip: use c64flt.GETADRAY to get A/Y output; lo/hi switched to normal little endian order)
-asmsub	GETADR		() clobbers(X) -> ubyte @ Y, ubyte @ A  = $b7f7
-
-asmsub	QINT		() clobbers(A,X,Y)			= $bc9b		; fac1 -> 4-byte signed integer in 98-101 ($62-$65), with the MSB FIRST.
-asmsub	AYINT		() clobbers(A,X,Y)			= $b1bf		; fac1-> signed word in 100-101 ($64-$65) MSB FIRST. (might throw ILLEGAL QUANTITY)
-
-; GIVAYF: signed word in Y/A (note different lsb/msb order) -> float in fac1
-; (tip: use c64flt.GIVAYFAY to use A/Y input; lo/hi switched to normal order)
-; there is also c64flt.GIVUAYFAY - unsigned word in A/Y (lo/hi) to fac1
-; there is also c64flt.FREADS32  that reads from 98-101 ($62-$65) MSB FIRST
-; there is also c64flt.FREADUS32  that reads from 98-101 ($62-$65) MSB FIRST
-; there is also c64flt.FREADS24AXY  that reads signed int24 into fac1 from A/X/Y (lo/mid/hi bytes)
-asmsub	GIVAYF		(ubyte lo @ Y, ubyte hi @ A) clobbers(A,X,Y)	= $b391
-
-asmsub	FREADUY		(ubyte value @ Y) clobbers(A,X,Y)	= $b3a2		; 8 bit unsigned Y -> float in fac1
-asmsub	FREADSA		(byte value @ A) clobbers(A,X,Y)	= $bc3c		; 8 bit signed A -> float in fac1
-asmsub	FREADSTR	(ubyte length @ A) clobbers(A,X,Y)	= $b7b5		; str -> fac1, $22/23 must point to string, A=string length
-asmsub	FPRINTLN	() clobbers(A,X,Y)			= $aabc		; print string of fac1, on one line (= with newline) destroys fac1.  (consider FOUT + STROUT as well)
-asmsub	FOUT		() clobbers(X) -> uword @ AY		= $bddd		; fac1 -> string, address returned in AY ($0100)
-
-asmsub	FADDH		() clobbers(A,X,Y)			= $b849		; fac1 += 0.5, for rounding- call this before INT
-asmsub	MUL10		() clobbers(A,X,Y)			= $bae2		; fac1 *= 10
-asmsub	DIV10		() clobbers(A,X,Y)			= $bafe		; fac1 /= 10 , CAUTION: result is always positive!
-asmsub	FCOMP		(uword mflpt @ AY) clobbers(X,Y) -> ubyte @ A = $bc5b		; A = compare fac1 to mflpt in A/Y, 0=equal 1=fac1 is greater, 255=fac1 is less than
-
-asmsub	FADDT		() clobbers(A,X,Y)			= $b86a		; fac1 += fac2
-asmsub	FADD		(uword mflpt @ AY) clobbers(A,X,Y)	= $b867		; fac1 += mflpt value from A/Y
-asmsub	FSUBT		() clobbers(A,X,Y)			= $b853		; fac1 = fac2-fac1   mind the order of the operands
-asmsub	FSUB		(uword mflpt @ AY) clobbers(A,X,Y)	= $b850		; fac1 = mflpt from A/Y - fac1
-asmsub	FMULTT 		() clobbers(A,X,Y)			= $ba2b		; fac1 *= fac2
-asmsub	FMULT		(uword mflpt @ AY) clobbers(A,X,Y)	= $ba28		; fac1 *= mflpt value from A/Y
-asmsub	FDIVT 		() clobbers(A,X,Y)			= $bb12		; fac1 = fac2/fac1  (remainder in fac2)  mind the order of the operands
-asmsub	FDIV  		(uword mflpt @ AY) clobbers(A,X,Y)	= $bb0f		; fac1 = mflpt in A/Y / fac1  (remainder in fac2)
-asmsub	FPWRT		() clobbers(A,X,Y)			= $bf7b		; fac1 = fac2 ** fac1
-asmsub	FPWR		(uword mflpt @ AY) clobbers(A,X,Y)	= $bf78		; fac1 = fac2 ** mflpt from A/Y
-
-asmsub	NOTOP		() clobbers(A,X,Y)			= $aed4		; fac1 = NOT(fac1)
-asmsub	INT		() clobbers(A,X,Y)			= $bccc		; INT() truncates, use FADDH first to round instead of trunc
-asmsub	LOG		() clobbers(A,X,Y)			= $b9ea		; fac1 = LN(fac1)  (natural log)
-asmsub	SGN		() clobbers(A,X,Y)			= $bc39		; fac1 = SGN(fac1), result of SIGN (-1, 0 or 1)
-asmsub	SIGN		() -> ubyte @ A				= $bc2b		; SIGN(fac1) to A, $ff, $0, $1 for negative, zero, positive
-asmsub	ABS		()					= $bc58		; fac1 = ABS(fac1)
-asmsub	SQR		() clobbers(A,X,Y)			= $bf71		; fac1 = SQRT(fac1)
-asmsub	SQRA		() clobbers(A,X,Y)			= $bf74		; fac1 = SQRT(fac2)
-asmsub	EXP		() clobbers(A,X,Y)			= $bfed		; fac1 = EXP(fac1)  (e ** fac1)
-asmsub	NEGOP		() clobbers(A)				= $bfb4		; switch the sign of fac1
-asmsub	RND		() clobbers(A,X,Y)			= $e097		; fac1 = RND(fac1) float random number generator
-asmsub	COS		() clobbers(A,X,Y)			= $e264		; fac1 = COS(fac1)
-asmsub	SIN		() clobbers(A,X,Y)			= $e26b		; fac1 = SIN(fac1)
-asmsub	TAN		() clobbers(A,X,Y)			= $e2b4		; fac1 = TAN(fac1)
-asmsub	ATN		() clobbers(A,X,Y)			= $e30e		; fac1 = ATN(fac1)
-
-
-
-
-asmsub  FREADS32  () clobbers(A,X,Y)  {
-	; ---- fac1 = signed int32 from $62-$65 big endian (MSB FIRST)
-	%asm {{
-		lda  $62
-		eor  #$ff
-		asl  a
-		lda  #0
-		ldx  #$a0
-		jmp  $bc4f		; internal BASIC routine
-	}}
-}
-
-asmsub  FREADUS32  () clobbers(A,X,Y)  {
-	; ---- fac1 = uint32 from $62-$65 big endian (MSB FIRST)
-	%asm {{
-		sec
-		lda  #0
-		ldx  #$a0
-		jmp  $bc4f		; internal BASIC routine
-	}}
-}
-
-asmsub  FREADS24AXY  (ubyte lo @ A, ubyte mid @ X, ubyte hi @ Y) clobbers(A,X,Y)  {
-	; ---- fac1 = signed int24 (A/X/Y contain lo/mid/hi bytes)
-	;      note: there is no FREADU24AXY (unsigned), use FREADUS32 instead.
-	%asm {{
-		sty  $62
-		stx  $63
-		sta  $64
-		lda  $62
-		eor  #$FF
-		asl  a
-		lda  #0
-		sta  $65
-		ldx  #$98
-		jmp  $bc4f		; internal BASIC routine
-	}}
-}
-
-asmsub  GIVUAYFAY  (uword value @ AY) clobbers(A,X,Y)  {
-	; ---- unsigned 16 bit word in A/Y (lo/hi) to fac1
-	%asm {{
-		sty  $62
-		sta  $63
-		ldx  #$90
-		sec
-		jmp  $bc49		; internal BASIC routine
-	}}
-}
-
-asmsub  GIVAYFAY  (uword value @ AY) clobbers(A,X,Y)  {
-	; ---- signed 16 bit word in A/Y (lo/hi) to float in fac1
-	%asm {{
-		sta  c64.SCRATCH_ZPREG
-		tya
-		ldy  c64.SCRATCH_ZPREG
-		jmp  GIVAYF		; this uses the inverse order, Y/A
-	}}
-}
-
-asmsub  FTOSWRDAY  () clobbers(X) -> uword @ AY  {
-	; ---- fac1 to signed word in A/Y
-	%asm {{
-		jsr  FTOSWORDYA	; note the inverse Y/A order
-		sta  c64.SCRATCH_ZPREG
-		tya
-		ldy  c64.SCRATCH_ZPREG
-		rts
-	}}
-}
-
-asmsub  GETADRAY  () clobbers(X) -> uword @ AY  {
-	; ---- fac1 to unsigned word in A/Y
-	%asm {{
-		jsr  GETADR		; this uses the inverse order, Y/A
-		sta  c64.SCRATCH_ZPB1
-		tya
-		ldy  c64.SCRATCH_ZPB1
-		rts
-	}}
-}
-
-sub  print_f  (float value) {
-	; ---- prints the floating point value (without a newline) using basic rom routines.
-	%asm {{
-		stx  c64.SCRATCH_ZPREGX
-		lda  #<value
-		ldy  #>value
-		jsr  MOVFM		; load float into fac1
-		jsr  FOUT		; fac1 to string in A/Y
-		jsr  c64.STROUT			; print string in A/Y
-		ldx  c64.SCRATCH_ZPREGX
-		rts
-	}}
-}
-
-sub  print_fln  (float value) {
-	; ---- prints the floating point value (with a newline at the end) using basic rom routines
-	%asm {{
-		stx  c64.SCRATCH_ZPREGX
-		lda  #<print_fln_value
-		ldy  #>print_fln_value
-		jsr  MOVFM		; load float into fac1
-		jsr  FPRINTLN		; print fac1 with newline
-		ldx  c64.SCRATCH_ZPREGX
-		rts
-	}}
-
-}
-
-
-; --- low level floating point assembly routines
-%asm {{
-ub2float	.proc
-		; -- convert ubyte in SCRATCH_ZPB1 to float at address A/Y
-		;    clobbers A, Y
-		stx  c64.SCRATCH_ZPREGX
-		sta  c64.SCRATCH_ZPWORD2
-		sty  c64.SCRATCH_ZPWORD2+1
-		ldy  c64.SCRATCH_ZPB1
-		jsr  FREADUY
-_fac_to_mem	ldx  c64.SCRATCH_ZPWORD2
-		ldy  c64.SCRATCH_ZPWORD2+1
-		jsr  MOVMF
-		ldx  c64.SCRATCH_ZPREGX
-		rts
-		.pend
-
-b2float		.proc
-		; -- convert byte in SCRATCH_ZPB1 to float at address A/Y
-		;    clobbers A, Y
-		stx  c64.SCRATCH_ZPREGX
-		sta  c64.SCRATCH_ZPWORD2
-		sty  c64.SCRATCH_ZPWORD2+1
-		lda  c64.SCRATCH_ZPB1
-		jsr  FREADSA
-		jmp  ub2float._fac_to_mem
-		.pend
-
-uw2float	.proc
-		; -- convert uword in SCRATCH_ZPWORD1 to float at address A/Y
-		stx  c64.SCRATCH_ZPREGX
-		sta  c64.SCRATCH_ZPWORD2
-		sty  c64.SCRATCH_ZPWORD2+1
-		lda  c64.SCRATCH_ZPWORD1
-		ldy  c64.SCRATCH_ZPWORD1+1
-		jsr  GIVUAYFAY
-		jmp  ub2float._fac_to_mem
-		.pend
-
-w2float		.proc
-		; -- convert word in SCRATCH_ZPWORD1 to float at address A/Y
-		stx  c64.SCRATCH_ZPREGX
-		sta  c64.SCRATCH_ZPWORD2
-		sty  c64.SCRATCH_ZPWORD2+1
-		ldy  c64.SCRATCH_ZPWORD1
-		lda  c64.SCRATCH_ZPWORD1+1
-		jsr  GIVAYF
-		jmp  ub2float._fac_to_mem
-		.pend
-
-stack_b2float	.proc
-		; -- b2float operating on the stack
-		inx
-		lda  c64.ESTACK_LO,x
-		stx  c64.SCRATCH_ZPREGX
-		jsr  FREADSA
-		jmp  push_fac1_as_result
-		.pend
-
-stack_w2float	.proc
-		; -- w2float operating on the stack
-		inx
-		ldy  c64.ESTACK_LO,x
-		lda  c64.ESTACK_HI,x
-		stx  c64.SCRATCH_ZPREGX
-		jsr  GIVAYF
-		jmp  push_fac1_as_result
-		.pend
-
-stack_ub2float	.proc
-		; -- ub2float operating on the stack
-		inx
-		lda  c64.ESTACK_LO,x
-		stx  c64.SCRATCH_ZPREGX
-		tay
-		jsr  FREADUY
-		jmp  push_fac1_as_result
-		.pend
-
-stack_uw2float	.proc
-		; -- uw2float operating on the stack
-		inx
-		lda  c64.ESTACK_LO,x
-		ldy  c64.ESTACK_HI,x
-		stx  c64.SCRATCH_ZPREGX
-		jsr  GIVUAYFAY
-		jmp  push_fac1_as_result
-		.pend
-
-stack_float2w	.proc               ; also used for float2b
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		jsr  AYINT
-		ldx  c64.SCRATCH_ZPREGX
-		lda  $64
-		sta  c64.ESTACK_HI,x
-		lda  $65
-		sta  c64.ESTACK_LO,x
-		dex
-		rts
-		.pend
-
-stack_float2uw	.proc               ; also used for float2ub
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		jsr  GETADR
-		ldx  c64.SCRATCH_ZPREGX
-		sta  c64.ESTACK_HI,x
-		tya
-		sta  c64.ESTACK_LO,x
-		dex
-		rts
-		.pend
-
-push_float	.proc
-		; ---- push mflpt5 in A/Y onto stack
-		; (taking 3 stack positions = 6 bytes of which 1 is padding)
-		sta  c64.SCRATCH_ZPWORD1
-		sty  c64.SCRATCH_ZPWORD1+1
-		ldy  #0
-		lda  (c64.SCRATCH_ZPWORD1),y
-		sta  c64.ESTACK_LO,x
-		iny
-		lda  (c64.SCRATCH_ZPWORD1),y
-		sta  c64.ESTACK_HI,x
-		dex
-		iny
-		lda  (c64.SCRATCH_ZPWORD1),y
-		sta  c64.ESTACK_LO,x
-		iny
-		lda  (c64.SCRATCH_ZPWORD1),y
-		sta  c64.ESTACK_HI,x
-		dex
-		iny
-		lda  (c64.SCRATCH_ZPWORD1),y
-		sta  c64.ESTACK_LO,x
-		dex
-		rts
-		.pend
-
-func_rndf	.proc
-		; -- put a random floating point value on the stack
-		stx  c64.SCRATCH_ZPREG
-		lda  #1
-		jsr  FREADSA
-		jsr  RND		; rng into fac1
-		ldx  #<_rndf_rnum5
-		ldy  #>_rndf_rnum5
-		jsr  MOVMF	; fac1 to mem X/Y
-		ldx  c64.SCRATCH_ZPREG
-		lda  #<_rndf_rnum5
-		ldy  #>_rndf_rnum5
-		jmp  push_float
-_rndf_rnum5	.byte  0,0,0,0,0
-		.pend
-
-push_float_from_indexed_var	.proc
-		; -- push the float from the array at A/Y with index on stack, onto the stack.
-		sta  c64.SCRATCH_ZPWORD1
-		sty  c64.SCRATCH_ZPWORD1+1
-		jsr  prog8_lib.pop_index_times_5
-		jsr  prog8_lib.add_a_to_zpword
-		lda  c64.SCRATCH_ZPWORD1
-		ldy  c64.SCRATCH_ZPWORD1+1
-		jmp  push_float
-		.pend
-
-pop_float	.proc
-		; ---- pops mflpt5 from stack to memory A/Y
-		; (frees 3 stack positions = 6 bytes of which 1 is padding)
-		sta  c64.SCRATCH_ZPWORD1
-		sty  c64.SCRATCH_ZPWORD1+1
-		ldy  #4
-		inx
-		lda  c64.ESTACK_LO,x
-		sta  (c64.SCRATCH_ZPWORD1),y
-		dey
-		inx
-		lda  c64.ESTACK_HI,x
-		sta  (c64.SCRATCH_ZPWORD1),y
-		dey
-		lda  c64.ESTACK_LO,x
-		sta  (c64.SCRATCH_ZPWORD1),y
-		dey
-		inx
-		lda  c64.ESTACK_HI,x
-		sta  (c64.SCRATCH_ZPWORD1),y
-		dey
-		lda  c64.ESTACK_LO,x
-		sta  (c64.SCRATCH_ZPWORD1),y
-		rts
-		.pend
-
-pop_float_fac1	.proc
-		; -- pops float from stack into FAC1
-		lda  #<fmath_float1
-		ldy  #>fmath_float1
-		jsr  pop_float
-		lda  #<fmath_float1
-		ldy  #>fmath_float1
-		jmp  MOVFM
-		.pend
-
-pop_float_to_indexed_var	.proc
-		; -- pop the float on the stack, to the memory in the array at A/Y indexed by the byte on stack
-		sta  c64.SCRATCH_ZPWORD1
-		sty  c64.SCRATCH_ZPWORD1+1
-		jsr  prog8_lib.pop_index_times_5
-		jsr  prog8_lib.add_a_to_zpword
-		lda  c64.SCRATCH_ZPWORD1
-		ldy  c64.SCRATCH_ZPWORD1+1
-		jmp  pop_float
-		.pend
-
-copy_float	.proc
-		; -- copies the 5 bytes of the mflt value pointed to by SCRATCH_ZPWORD1,
-		;    into the 5 bytes pointed to by A/Y.  Clobbers A,Y.
-		sta  c64.SCRATCH_ZPWORD2
-		sty  c64.SCRATCH_ZPWORD2+1
-		ldy  #0
-		lda  (c64.SCRATCH_ZPWORD1),y
-		sta  (c64.SCRATCH_ZPWORD2),y
-		iny
-		lda  (c64.SCRATCH_ZPWORD1),y
-		sta  (c64.SCRATCH_ZPWORD2),y
-		iny
-		lda  (c64.SCRATCH_ZPWORD1),y
-		sta  (c64.SCRATCH_ZPWORD2),y
-		iny
-		lda  (c64.SCRATCH_ZPWORD1),y
-		sta  (c64.SCRATCH_ZPWORD2),y
-		iny
-		lda  (c64.SCRATCH_ZPWORD1),y
-		sta  (c64.SCRATCH_ZPWORD2),y
-		rts
-		.pend
-
-inc_var_f	.proc
-		; -- add 1 to float pointed to by A/Y
-		sta  c64.SCRATCH_ZPWORD1
-		sty  c64.SCRATCH_ZPWORD1+1
-		stx  c64.SCRATCH_ZPREGX
-		jsr  MOVFM
-		lda  #<FL_FONE
-		ldy  #>FL_FONE
-		jsr  FADD
-		ldx  c64.SCRATCH_ZPWORD1
-		ldy  c64.SCRATCH_ZPWORD1+1
-		jsr  MOVMF
-		ldx  c64.SCRATCH_ZPREGX
-		rts
-		.pend
-
-dec_var_f	.proc
-		; -- subtract 1 from float pointed to by A/Y
-		sta  c64.SCRATCH_ZPWORD1
-		sty  c64.SCRATCH_ZPWORD1+1
-		stx  c64.SCRATCH_ZPREGX
-		lda  #<FL_FONE
-		ldy  #>FL_FONE
-		jsr  MOVFM
-		lda  c64.SCRATCH_ZPWORD1
-		ldy  c64.SCRATCH_ZPWORD1+1
-		jsr  FSUB
-		ldx  c64.SCRATCH_ZPWORD1
-		ldy  c64.SCRATCH_ZPWORD1+1
-		jsr  MOVMF
-		ldx  c64.SCRATCH_ZPREGX
-		rts
-		.pend
-
-inc_indexed_var_f	.proc
-		; -- add 1 to float in array pointed to by A/Y, at index X
-		pha
-		txa
-		sta  c64.SCRATCH_ZPB1
-		asl  a
-		asl  a
-		clc
-		adc  c64.SCRATCH_ZPB1
-		sta  c64.SCRATCH_ZPB1
-		pla
-		clc
-		adc  c64.SCRATCH_ZPB1
-		bcc  +
-		iny
-+		jmp  inc_var_f
-		.pend
-
-dec_indexed_var_f	.proc
-		; -- subtract 1 to float in array pointed to by A/Y, at index X
-		pha
-		txa
-		sta  c64.SCRATCH_ZPB1
-		asl  a
-		asl  a
-		clc
-		adc  c64.SCRATCH_ZPB1
-		sta  c64.SCRATCH_ZPB1
-		pla
-		clc
-		adc  c64.SCRATCH_ZPB1
-		bcc  +
-		iny
-+		jmp  dec_var_f
-		.pend
-
-
-pop_2_floats_f2_in_fac1	.proc
-		; -- pop 2 floats from stack, load the second one in FAC1 as well
-		lda  #<fmath_float2
-		ldy  #>fmath_float2
-		jsr  pop_float
-		lda  #<fmath_float1
-		ldy  #>fmath_float1
-		jsr  pop_float
-		lda  #<fmath_float2
-		ldy  #>fmath_float2
-		jmp  MOVFM
-		.pend
-
-
-fmath_float1	.byte 0,0,0,0,0	; storage for a mflpt5 value
-fmath_float2	.byte 0,0,0,0,0	; storage for a mflpt5 value
-
-push_fac1_as_result	.proc
-		; -- push the float in FAC1 onto the stack, and return from calculation
-		ldx  #<fmath_float1
-		ldy  #>fmath_float1
-		jsr  MOVMF
-		lda  #<fmath_float1
-		ldy  #>fmath_float1
-		ldx  c64.SCRATCH_ZPREGX
-		jmp  push_float
-		.pend
-
-pow_f		.proc
-		; -- push f1 ** f2 on stack
-		lda  #<fmath_float2
-		ldy  #>fmath_float2
-		jsr  pop_float
-		lda  #<fmath_float1
-		ldy  #>fmath_float1
-		jsr  pop_float
-		stx  c64.SCRATCH_ZPREGX
-		lda  #<fmath_float1
-		ldy  #>fmath_float1
-		jsr  CONUPK		; fac2 = float1
-		lda  #<fmath_float2
-		ldy  #>fmath_float2
-		jsr  FPWR
-		ldx  c64.SCRATCH_ZPREGX
-		jmp  push_fac1_as_result
-		.pend
-
-div_f		.proc
-		; -- push f1/f2 on stack
-		jsr  pop_2_floats_f2_in_fac1
-		stx  c64.SCRATCH_ZPREGX
-		lda  #<fmath_float1
-		ldy  #>fmath_float1
-		jsr  FDIV
-		jmp  push_fac1_as_result
-		.pend
-
-add_f		.proc
-		; -- push f1+f2 on stack
-		jsr  pop_2_floats_f2_in_fac1
-		stx  c64.SCRATCH_ZPREGX
-		lda  #<fmath_float1
-		ldy  #>fmath_float1
-		jsr  FADD
-		jmp  push_fac1_as_result
-		.pend
-
-sub_f		.proc
-		; -- push f1-f2 on stack
-		jsr  pop_2_floats_f2_in_fac1
-		stx  c64.SCRATCH_ZPREGX
-		lda  #<fmath_float1
-		ldy  #>fmath_float1
-		jsr  FSUB
-		jmp  push_fac1_as_result
-		.pend
-
-mul_f		.proc
-		; -- push f1*f2 on stack
-		jsr  pop_2_floats_f2_in_fac1
-		stx  c64.SCRATCH_ZPREGX
-		lda  #<fmath_float1
-		ldy  #>fmath_float1
-		jsr  FMULT
-		jmp  push_fac1_as_result
-		.pend
-
-neg_f		.proc
-		; -- push -flt back on stack
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		jsr  NEGOP
-		jmp  push_fac1_as_result
-		.pend
-
-abs_f		.proc
-		; -- push abs(float) on stack (as float)
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		jsr  ABS
-		jmp  push_fac1_as_result
-		.pend
-
-equal_f		.proc
-		; -- are the two mflpt5 numbers on the stack identical?
-		inx
-		inx
-		inx
-		inx
-		lda  c64.ESTACK_LO-3,x
-		cmp  c64.ESTACK_LO,x
-		bne  _equals_false
-		lda  c64.ESTACK_LO-2,x
-		cmp  c64.ESTACK_LO+1,x
-		bne  _equals_false
-		lda  c64.ESTACK_LO-1,x
-		cmp  c64.ESTACK_LO+2,x
-		bne  _equals_false
-		lda  c64.ESTACK_HI-2,x
-		cmp  c64.ESTACK_HI+1,x
-		bne  _equals_false
-		lda  c64.ESTACK_HI-1,x
-		cmp  c64.ESTACK_HI+2,x
-		bne  _equals_false
-_equals_true	lda  #1
-_equals_store	inx
-		sta  c64.ESTACK_LO+1,x
-		rts
-_equals_false	lda  #0
-		beq  _equals_store
-		.pend
-
-notequal_f	.proc
-		; -- are the two mflpt5 numbers on the stack different?
-		jsr  equal_f
-		eor  #1		; invert the result
-		sta  c64.ESTACK_LO+1,x
-		rts
-		.pend
-
-less_f		.proc
-		; -- is f1 < f2?
-		jsr  compare_floats
-		cmp  #255
-		beq  compare_floats._return_true
-		bne  compare_floats._return_false
-		.pend
-
-
-lesseq_f	.proc
-		; -- is f1 <= f2?
-		jsr  compare_floats
-		cmp  #255
-		beq  compare_floats._return_true
-		cmp  #0
-		beq  compare_floats._return_true
-		bne  compare_floats._return_false
-		.pend
-
-greater_f	.proc
-		; -- is f1 > f2?
-		jsr  compare_floats
-		cmp  #1
-		beq  compare_floats._return_true
-		bne  compare_floats._return_false
-		.pend
-
-greatereq_f	.proc
-		; -- is f1 >= f2?
-		jsr  compare_floats
-		cmp  #1
-		beq  compare_floats._return_true
-		cmp  #0
-		beq  compare_floats._return_true
-		bne  compare_floats._return_false
-		.pend
-
-compare_floats	.proc
-		lda  #<fmath_float2
-		ldy  #>fmath_float2
-		jsr  pop_float
-		lda  #<fmath_float1
-		ldy  #>fmath_float1
-		jsr  pop_float
-		lda  #<fmath_float1
-		ldy  #>fmath_float1
-		jsr  MOVFM		; fac1 = flt1
-		lda  #<fmath_float2
-		ldy  #>fmath_float2
-		stx  c64.SCRATCH_ZPREG
-		jsr  FCOMP		; A = flt1 compared with flt2 (0=equal, 1=flt1>flt2, 255=flt1<flt2)
-		ldx  c64.SCRATCH_ZPREG
-		rts
-_return_false	lda  #0
-_return_result  sta  c64.ESTACK_LO,x
-		dex
-		rts
-_return_true	lda  #1
-		bne  _return_result
-		.pend
-
-func_sin	.proc
-		; -- push sin(f) back onto stack
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		jsr  SIN
-		jmp  push_fac1_as_result
-		.pend
-
-func_cos	.proc
-		; -- push cos(f) back onto stack
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		jsr  COS
-		jmp  push_fac1_as_result
-		.pend
-
-func_tan	.proc
-		; -- push tan(f) back onto stack
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		jsr  TAN
-		jmp  push_fac1_as_result
-		.pend
-
-func_atan	.proc
-		; -- push atan(f) back onto stack
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		jsr  ATN
-		jmp  push_fac1_as_result
-		.pend
-
-func_ln		.proc
-		; -- push ln(f) back onto stack
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		jsr  LOG
-		jmp  push_fac1_as_result
-		.pend
-
-func_log2	.proc
-		; -- push log base 2, ln(f)/ln(2), back onto stack
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		jsr  LOG
-		jsr  MOVEF
-		lda  #<c64.FL_LOG2
-		ldy  #>c64.FL_LOG2
-		jsr  MOVFM
-		jsr  FDIVT
-		jmp  push_fac1_as_result
-		.pend
-
-func_sqrt	.proc
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		jsr  SQR
-		jmp  push_fac1_as_result
-		.pend
-
-func_rad	.proc
-		; -- convert degrees to radians (d * pi / 180)
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		lda  #<_pi_div_180
-		ldy  #>_pi_div_180
-		jsr  FMULT
-		jmp  push_fac1_as_result
-_pi_div_180	.byte 123, 14, 250, 53, 18		; pi / 180
-		.pend
-
-func_deg	.proc
-		; -- convert radians to degrees (d * (1/ pi * 180))
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		lda  #<_one_over_pi_div_180
-		ldy  #>_one_over_pi_div_180
-		jsr  FMULT
-		jmp  push_fac1_as_result
-_one_over_pi_div_180	.byte 134, 101, 46, 224, 211		; 1 / (pi * 180)
-		.pend
-
-func_round	.proc
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		jsr  FADDH
-		jsr  INT
-		jmp  push_fac1_as_result
-		.pend
-
-func_floor	.proc
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		jsr  INT
-		jmp  push_fac1_as_result
-		.pend
-
-func_ceil	.proc
-		; -- ceil: tr = int(f); if tr==f -> return  else return tr+1
-		jsr  pop_float_fac1
-		stx  c64.SCRATCH_ZPREGX
-		ldx  #<fmath_float1
-		ldy  #>fmath_float1
-		jsr  MOVMF
-		jsr  INT
-		lda  #<fmath_float1
-		ldy  #>fmath_float1
-		jsr  FCOMP
-		cmp  #0
-		beq  +
-		lda  #<FL_FONE
-		ldy  #>FL_FONE
-		jsr  FADD
-+		jmp  push_fac1_as_result
-		.pend
-
-func_any_f	.proc
-		inx
-		lda  c64.ESTACK_LO,x	; array size
-		sta  c64.SCRATCH_ZPB1
-		asl  a
-		asl  a
-		clc
-		adc  c64.SCRATCH_ZPB1	; times 5 because of float
-		jmp  prog8_lib.func_any_b._entry
-		.pend
-
-func_all_f	.proc
-		inx
-		jsr  prog8_lib.peek_address
-		lda  c64.ESTACK_LO,x	; array size
-		sta  c64.SCRATCH_ZPB1
-		asl  a
-		asl  a
-		clc
-		adc  c64.SCRATCH_ZPB1	; times 5 because of float
-		tay
-		dey
--		lda  (c64.SCRATCH_ZPWORD1),y
-		clc
-		dey
-		adc  (c64.SCRATCH_ZPWORD1),y
-		dey
-		adc  (c64.SCRATCH_ZPWORD1),y
-		dey
-		adc  (c64.SCRATCH_ZPWORD1),y
-		dey
-		adc  (c64.SCRATCH_ZPWORD1),y
-		dey
-		cmp  #0
-		beq  +
-        cpy  #255
-        bne  -
-		lda  #1
-		sta  c64.ESTACK_LO+1,x
-		rts
-+		sta  c64.ESTACK_LO+1,x
-		rts
-		.pend
-
-func_max_f	.proc
-		lda  #255
-		sta  _minmax_cmp+1
-		lda  #<_largest_neg_float
-		ldy  #>_largest_neg_float
-_minmax_entry	jsr  MOVFM
-		jsr  prog8_lib.pop_array_and_lengthmin1Y
-		stx  c64.SCRATCH_ZPREGX
--		sty  c64.SCRATCH_ZPREG
-		lda  c64.SCRATCH_ZPWORD1
-		ldy  c64.SCRATCH_ZPWORD1+1
-		jsr  FCOMP
-_minmax_cmp	cmp  #255			; modified
-		bne  +
-		lda  c64.SCRATCH_ZPWORD1
-		ldy  c64.SCRATCH_ZPWORD1+1
-		jsr  MOVFM
-+		lda  c64.SCRATCH_ZPWORD1
-		clc
-		adc  #5
-		sta  c64.SCRATCH_ZPWORD1
-		bcc  +
-		inc  c64.SCRATCH_ZPWORD1+1
-+		ldy  c64.SCRATCH_ZPREG
-		dey
-		cpy  #255
-		bne  -
-		jmp  push_fac1_as_result
-_largest_neg_float	.byte 255,255,255,255,255		; largest negative float -1.7014118345e+38
-		.pend
-
-func_min_f	.proc
-		lda  #1
-		sta  func_max_f._minmax_cmp+1
-		lda  #<_largest_pos_float
-		ldy  #>_largest_pos_float
-		jmp  func_max_f._minmax_entry
-_largest_pos_float	.byte  255,127,255,255,255		; largest positive float
-		rts
-		.pend
-
-func_sum_f	.proc
-		lda  #<FL_ZERO
-		ldy  #>FL_ZERO
-		jsr  MOVFM
-		jsr  prog8_lib.pop_array_and_lengthmin1Y
-		stx  c64.SCRATCH_ZPREGX
--		sty  c64.SCRATCH_ZPREG
-		lda  c64.SCRATCH_ZPWORD1
-		ldy  c64.SCRATCH_ZPWORD1+1
-		jsr  FADD
-		ldy  c64.SCRATCH_ZPREG
-		dey
-		cpy  #255
-		beq  +
-		lda  c64.SCRATCH_ZPWORD1
-		clc
-		adc  #5
-		sta  c64.SCRATCH_ZPWORD1
-		bcc  -
-		inc  c64.SCRATCH_ZPWORD1+1
-		bne  -
-+		jmp  push_fac1_as_result
-		.pend
-		
-sign_f		.proc
-		jsr  pop_float_fac1
-		jsr  SIGN
-		sta  c64.ESTACK_LO,x
-		dex
-		rts
-		.pend
-		
-
-}}
-
-}  ; ------ end of block c64flt

compiler/res/prog8lib/c64lib.p8

@@ -1,243 +0,0 @@
-; 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 {
-		const   uword  ESTACK_LO	= $ce00		; evaluation stack (lsb)
-		const   uword  ESTACK_HI	= $cf00		; evaluation stack (msb)
-		&ubyte  SCRATCH_ZPB1		= $02		; scratch byte 1 in ZP
-		&ubyte  SCRATCH_ZPREG		= $03		; scratch register in ZP
-		&ubyte  SCRATCH_ZPREGX		= $fa		; temp storage for X register (stack pointer)
-		&uword  SCRATCH_ZPWORD1		= $fb		; scratch word in ZP ($fb/$fc)
-		&uword  SCRATCH_ZPWORD2		= $fd		; scratch word in ZP ($fd/$fe)
-
-
-		&ubyte  TIME_HI			= $a0		; software jiffy clock, hi byte
-		&ubyte  TIME_MID		= $a1		;  .. mid byte
-		&ubyte  TIME_LO			= $a2		;    .. lo byte. Updated by IRQ every 1/60 sec
-		&ubyte  STKEY			= $91		; various keyboard statuses (updated by IRQ)
-		&ubyte  SFDX			= $cb		; current key pressed (matrix value) (updated by IRQ)
-
-		&ubyte  COLOR			= $0286		; cursor color
-		&ubyte  HIBASE			= $0288		; screen base address / 256 (hi-byte of screen memory address)
-		&uword  CINV			= $0314		; IRQ vector
-		&uword  NMI_VEC			= $FFFA		; 6502 nmi vector, determined by the kernal if banked in
-		&uword  RESET_VEC		= $FFFC		; 6502 reset vector, determined by the kernal if banked in
-		&uword  IRQ_VEC			= $FFFE		; 6502 interrupt vector, determined by the kernal if banked in
-
-		; the default addresses for the character screen chars and colors
-		const   uword  Screen		= $0400		; to have this as an array[40*25] the compiler would have to support array size > 255
-		const   uword  Colors		= $d800		; to have this as an array[40*25] the compiler would have to support array size > 255
-
-		; the default locations of the 8 sprite pointers (store address of sprite / 64)
-		&ubyte  SPRPTR0			= 2040
-		&ubyte  SPRPTR1			= 2041
-		&ubyte  SPRPTR2			= 2042
-		&ubyte  SPRPTR3			= 2043
-		&ubyte  SPRPTR4			= 2044
-		&ubyte  SPRPTR5			= 2045
-		&ubyte  SPRPTR6			= 2046
-		&ubyte  SPRPTR7			= 2047
-		&ubyte[8]  SPRPTR		= 2040		; the 8 sprite pointers as an array.
-
-
-; ---- VIC-II 6567/6569/856x registers ----
-
-		&ubyte  SP0X		= $d000
-		&ubyte  SP0Y		= $d001
-		&ubyte  SP1X		= $d002
-		&ubyte  SP1Y		= $d003
-		&ubyte  SP2X		= $d004
-		&ubyte  SP2Y		= $d005
-		&ubyte  SP3X		= $d006
-		&ubyte  SP3Y		= $d007
-		&ubyte  SP4X		= $d008
-		&ubyte  SP4Y		= $d009
-		&ubyte  SP5X		= $d00a
-		&ubyte  SP5Y		= $d00b
-		&ubyte  SP6X		= $d00c
-		&ubyte  SP6Y		= $d00d
-		&ubyte  SP7X		= $d00e
-		&ubyte  SP7Y		= $d00f
-		&ubyte[16]  SPXY	= $d000		; the 8 sprite X and Y registers as an array.
-		&uword[8]  SPXYW	= $d000		; the 8 sprite X and Y registers as a combined xy word array.
-
-		&ubyte  MSIGX		= $d010
-		&ubyte  SCROLY		= $d011
-		&ubyte  RASTER		= $d012
-		&ubyte  LPENX		= $d013
-		&ubyte  LPENY		= $d014
-		&ubyte  SPENA		= $d015
-		&ubyte  SCROLX		= $d016
-		&ubyte  YXPAND		= $d017
-		&ubyte  VMCSB		= $d018
-		&ubyte  VICIRQ		= $d019
-		&ubyte  IREQMASK	= $d01a
-		&ubyte  SPBGPR		= $d01b
-		&ubyte  SPMC		= $d01c
-		&ubyte  XXPAND		= $d01d
-		&ubyte  SPSPCL		= $d01e
-		&ubyte  SPBGCL		= $d01f
-
-		&ubyte  EXTCOL		= $d020		; border color
-		&ubyte  BGCOL0		= $d021		; screen color
-		&ubyte  BGCOL1		= $d022
-		&ubyte  BGCOL2		= $d023
-		&ubyte  BGCOL4		= $d024
-		&ubyte  SPMC0		= $d025
-		&ubyte  SPMC1		= $d026
-		&ubyte  SP0COL		= $d027
-		&ubyte  SP1COL		= $d028
-		&ubyte  SP2COL		= $d029
-		&ubyte  SP3COL		= $d02a
-		&ubyte  SP4COL		= $d02b
-		&ubyte  SP5COL		= $d02c
-		&ubyte  SP6COL		= $d02d
-		&ubyte  SP7COL		= $d02e
-		&ubyte[8]  SPCOL	= $d027
-
-
-; ---- end of VIC-II registers ----
-
-; ---- CIA 6526 1 & 2 registers ----
-
-		&ubyte  CIA1PRA		= $DC00		; CIA 1 DRA, keyboard column drive (and joystick control port #2)
-		&ubyte  CIA1PRB		= $DC01		; CIA 1 DRB, keyboard row port (and joystick control port #1)
-		&ubyte  CIA1DDRA	= $DC02		; CIA 1 DDRA, keyboard column
-		&ubyte  CIA1DDRB	= $DC03		; CIA 1 DDRB, keyboard row
-		&ubyte  CIA1TAL		= $DC04		; CIA 1 timer A low byte
-		&ubyte  CIA1TAH		= $DC05		; CIA 1 timer A high byte
-		&ubyte  CIA1TBL		= $DC06		; CIA 1 timer B low byte
-		&ubyte  CIA1TBH		= $DC07		; CIA 1 timer B high byte
-		&ubyte  CIA1TOD10	= $DC08		; time of day, 1/10 sec.
-		&ubyte  CIA1TODSEC	= $DC09		; time of day, seconds
-		&ubyte  CIA1TODMMIN	= $DC0A		; time of day, minutes
-		&ubyte  CIA1TODHR	= $DC0B		; time of day, hours
-		&ubyte  CIA1SDR		= $DC0C		; Serial Data Register
-		&ubyte  CIA1ICR		= $DC0D
-		&ubyte  CIA1CRA		= $DC0E
-		&ubyte  CIA1CRB		= $DC0F
-
-		&ubyte  CIA2PRA		= $DD00		; CIA 2 DRA, serial port and video address
-		&ubyte  CIA2PRB		= $DD01		; CIA 2 DRB, RS232 port / USERPORT
-		&ubyte  CIA2DDRA	= $DD02		; CIA 2 DDRA, serial port and video address
-		&ubyte  CIA2DDRB	= $DD03		; CIA 2 DDRB, RS232 port / USERPORT
-		&ubyte  CIA2TAL		= $DD04		; CIA 2 timer A low byte
-		&ubyte  CIA2TAH		= $DD05		; CIA 2 timer A high byte
-		&ubyte  CIA2TBL		= $DD06		; CIA 2 timer B low byte
-		&ubyte  CIA2TBH		= $DD07		; CIA 2 timer B high byte
-		&ubyte  CIA2TOD10	= $DD08		; time of day, 1/10 sec.
-		&ubyte  CIA2TODSEC	= $DD09		; time of day, seconds
-		&ubyte  CIA2TODMIN	= $DD0A		; time of day, minutes
-		&ubyte  CIA2TODHR	= $DD0B		; time of day, hours
-		&ubyte  CIA2SDR		= $DD0C		; Serial Data Register
-		&ubyte  CIA2ICR		= $DD0D
-		&ubyte  CIA2CRA		= $DD0E
-		&ubyte  CIA2CRB		= $DD0F
-
-; ---- end of CIA registers ----
-
-; ---- SID 6581/8580 registers ----
-
-		&ubyte  FREQLO1		= $D400		; channel 1 freq lo
-		&ubyte  FREQHI1		= $D401		; channel 1 freq hi
-		&uword  FREQ1		= $D400		; channel 1 freq (word)
-		&ubyte  PWLO1		= $D402		; channel 1 pulse width lo (7-0)
-		&ubyte  PWHI1		= $D403		; channel 1 pulse width hi (11-8)
-		&uword  PW1		= $D402		; channel 1 pulse width (word)
-		&ubyte  CR1		= $D404		; channel 1 voice control register
-		&ubyte  AD1		= $D405		; channel 1 attack & decay
-		&ubyte  SR1		= $D406		; channel 1 sustain & release
-		&ubyte  FREQLO2		= $D407		; channel 2 freq lo
-		&ubyte  FREQHI2		= $D408		; channel 2 freq hi
-		&uword  FREQ2		= $D407		; channel 2 freq (word)
-		&ubyte  PWLO2		= $D409		; channel 2 pulse width lo (7-0)
-		&ubyte  PWHI2		= $D40A		; channel 2 pulse width hi (11-8)
-		&uword  PW2		= $D409		; channel 2 pulse width (word)
-		&ubyte  CR2		= $D40B		; channel 2 voice control register
-		&ubyte  AD2		= $D40C		; channel 2 attack & decay
-		&ubyte  SR2		= $D40D		; channel 2 sustain & release
-		&ubyte  FREQLO3		= $D40E		; channel 3 freq lo
-		&ubyte  FREQHI3		= $D40F		; channel 3 freq hi
-		&uword  FREQ3		= $D40E		; channel 3 freq (word)
-		&ubyte  PWLO3		= $D410		; channel 3 pulse width lo (7-0)
-		&ubyte  PWHI3		= $D411		; channel 3 pulse width hi (11-8)
-		&uword  PW3		= $D410		; channel 3 pulse width (word)
-		&ubyte  CR3		= $D412		; channel 3 voice control register
-		&ubyte  AD3		= $D413		; channel 3 attack & decay
-		&ubyte  SR3		= $D414		; channel 3 sustain & release
-		&ubyte  FCLO		= $D415		; filter cutoff lo (2-0)
-		&ubyte  FCHI		= $D416		; filter cutoff hi (10-3)
-		&uword  FC		= $D415		; filter cutoff (word)
-		&ubyte  RESFILT		= $D417		; filter resonance and routing
-		&ubyte  MVOL		= $D418		; filter mode and main volume control
-		&ubyte  POTX		= $D419		; potentiometer X
-		&ubyte  POTY		= $D41A		; potentiometer Y
-		&ubyte  OSC3		= $D41B		; channel 3 oscillator value read
-		&ubyte  ENV3		= $D41C		; channel 3 envelope value read
-
-; ---- end of SID registers ----
-
-
-
-; ---- C64 basic routines ----
-
-asmsub	CLEARSCR	() clobbers(A,X,Y)		= $E544		; clear the screen
-asmsub	HOMECRSR	() clobbers(A,X,Y)		= $E566		; cursor to top left of screen
-
-
-; ---- end of C64 basic routines ----
-
-
-; ---- C64 kernal routines ----
-
-asmsub	STROUT   (uword strptr @ AY) clobbers(A, X, Y)	= $AB1E		; print null-terminated string (use c64scr.print instead)
-asmsub	IRQDFRT  () clobbers(A,X,Y)			= $EA31		; default IRQ routine
-asmsub	IRQDFEND () clobbers(A,X,Y)			= $EA81		; default IRQ end/cleanup
-asmsub	CINT     () clobbers(A,X,Y)			= $FF81		; (alias: SCINIT) initialize screen editor and video chip
-asmsub	IOINIT   () clobbers(A, X)			= $FF84		; initialize I/O devices (CIA, SID, IRQ)
-asmsub	RAMTAS   () clobbers(A,X,Y)			= $FF87		; initialize RAM, tape buffer, screen
-asmsub	RESTOR   () clobbers(A,X,Y)			= $FF8A		; restore default I/O vectors
-asmsub	VECTOR   (uword userptr @ XY, ubyte dir @ Pc) clobbers(A,Y)  = $FF8D		; read/set I/O vector table
-asmsub	SETMSG   (ubyte value @ A)			= $FF90		; set Kernal message control flag
-asmsub	SECOND   (ubyte address @ A) clobbers(A)	= $FF93		; (alias: LSTNSA) send secondary address after LISTEN
-asmsub	TKSA     (ubyte address @ A) clobbers(A)	= $FF96		; (alias: TALKSA) send secondary address after TALK
-asmsub	MEMTOP   (uword address @ XY, ubyte dir @ Pc) -> uword @ XY	= $FF99		; read/set top of memory  pointer
-asmsub	MEMBOT   (uword address @ XY, ubyte dir @ Pc) -> uword @ XY	= $FF9C		; read/set bottom of memory  pointer
-asmsub	SCNKEY   () clobbers(A,X,Y)			= $FF9F		; scan the keyboard
-asmsub	SETTMO   (ubyte timeout @ A)			= $FFA2		; set time-out flag for IEEE bus
-asmsub	ACPTR    () -> ubyte @ A			= $FFA5		; (alias: IECIN) input byte from serial bus
-asmsub	CIOUT    (ubyte databyte @ A)			= $FFA8		; (alias: IECOUT) output byte to serial bus
-asmsub	UNTLK    () clobbers(A)				= $FFAB		; command serial bus device to UNTALK
-asmsub	UNLSN    () clobbers(A)				= $FFAE		; command serial bus device to UNLISTEN
-asmsub	LISTEN   (ubyte device @ A) clobbers(A)		= $FFB1		; command serial bus device to LISTEN
-asmsub	TALK     (ubyte device @ A) clobbers(A)		= $FFB4		; command serial bus device to TALK
-asmsub	READST   () -> ubyte @ A			= $FFB7		; read I/O status word
-asmsub	SETLFS   (ubyte logical @ A, ubyte device @ X, ubyte address @ Y) = $FFBA	; set logical file parameters
-asmsub	SETNAM   (ubyte namelen @ A, str filename @ XY)	= $FFBD		; set filename parameters
-asmsub	OPEN     () clobbers(A,X,Y)			= $FFC0		; (via 794 ($31A)) open a logical file
-asmsub	CLOSE    (ubyte logical @ A) clobbers(A,X,Y)	= $FFC3		; (via 796 ($31C)) close a logical file
-asmsub	CHKIN    (ubyte logical @ X) clobbers(A,X)	= $FFC6		; (via 798 ($31E)) define an input channel
-asmsub	CHKOUT   (ubyte logical @ X) clobbers(A,X)	= $FFC9		; (via 800 ($320)) define an output channel
-asmsub	CLRCHN   () clobbers(A,X)			= $FFCC		; (via 802 ($322)) restore default devices
-asmsub	CHRIN    () clobbers(Y) -> ubyte @ A		= $FFCF		; (via 804 ($324)) input a character (for keyboard, read a whole line from the screen) A=byte read.
-asmsub	CHROUT   (ubyte char @ A)			= $FFD2		; (via 806 ($326)) output a character
-asmsub	LOAD     (ubyte verify @ A, uword address @ XY) -> ubyte @Pc, ubyte @ A, ubyte @ X, ubyte @ Y = $FFD5	; (via 816 ($330)) load from device
-asmsub	SAVE     (ubyte zp_startaddr @ A, uword endaddr @ XY) -> ubyte @ Pc, ubyte @ A = $FFD8	; (via 818 ($332)) save to a device
-asmsub	SETTIM   (ubyte low @ A, ubyte middle @ X, ubyte high @ Y)	= $FFDB		; set the software clock
-asmsub	RDTIM    () -> ubyte @ A, ubyte @ X, ubyte @ Y	= $FFDE	; read the software clock
-asmsub	STOP     () clobbers(A,X) -> ubyte @ Pz, ubyte @ Pc	= $FFE1		; (via 808 ($328)) check the STOP key
-asmsub	GETIN    () clobbers(X,Y) -> ubyte @ A		= $FFE4		; (via 810 ($32A)) get a character
-asmsub	CLALL    () clobbers(A,X)			= $FFE7		; (via 812 ($32C)) close all files
-asmsub	UDTIM    () clobbers(A,X)			= $FFEA		; update the software clock
-asmsub	SCREEN   () -> ubyte @ X, ubyte @ Y		= $FFED		; read number of screen rows and columns
-asmsub	PLOT     (ubyte col @ Y, ubyte row @ X, ubyte dir @ Pc) -> ubyte @ X, ubyte @ Y	= $FFF0		; read/set position of cursor on screen.  Use c64scr.plot for a 'safe' wrapper that preserves X.
-asmsub	IOBASE   () -> uword @ XY			= $FFF3		; read base address of I/O devices
-
-; ---- end of C64 kernal routines ----
-
-}

compiler/res/prog8lib/conv.p8

@@ -0,0 +1,453 @@
+; Prog8 definitions for number conversions routines.
+;
+; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
+;
+; indent format: TABS, size=8
+
+
+conv {
+
+; ----- number conversions to decimal strings
+
+asmsub  ubyte2decimal  (ubyte value @ A) -> ubyte @ Y, ubyte @ A, ubyte @ X  {
+	; ---- A to decimal string in Y/A/X  (100s in Y, 10s in A, 1s in X)
+    %asm {{
+        ldy  #uword2decimal.ASCII_0_OFFSET
+        bne  uword2decimal.hex_try200
+        rts
+	}}
+}
+
+asmsub  uword2decimal  (uword value @ AY) -> ubyte @Y, ubyte @A, ubyte @X  {
+    ;  ---- convert 16 bit uword in A/Y to decimal
+    ;  output in uword2decimal.decTenThousands, decThousands, decHundreds, decTens, decOnes
+    ;  (these are terminated by a zero byte so they can be easily printed)
+    ;  also returns Y = 100's, A = 10's, X = 1's
+
+    %asm {{
+
+;Convert 16 bit Hex to Decimal (0-65535) Rev 2
+;By Omegamatrix    Further optimizations by tepples
+; routine from http://forums.nesdev.com/viewtopic.php?f=2&t=11341&start=15
+
+;HexToDec99
+; start in A
+; end with A = 10's, decOnes (also in X)
+
+;HexToDec255
+; start in A
+; end with Y = 100's, A = 10's, decOnes (also in X)
+
+;HexToDec999
+; start with A = high byte, Y = low byte
+; end with Y = 100's, A = 10's, decOnes (also in X)
+; requires 1 extra temp register on top of decOnes, could combine
+; these two if HexToDec65535 was eliminated...
+
+;HexToDec65535
+; start with A/Y (low/high) as 16 bit value
+; end with decTenThousand, decThousand, Y = 100's, A = 10's, decOnes (also in X)
+; (irmen: I store Y and A in decHundreds and decTens too, so all of it can be easily printed)
+
+
+ASCII_0_OFFSET 	= $30
+temp       	    = P8ZP_SCRATCH_B1	; byte in zeropage
+hexHigh      	= P8ZP_SCRATCH_W1	; byte in zeropage
+hexLow       	= P8ZP_SCRATCH_W1+1	; byte in zeropage
+
+
+HexToDec65535; SUBROUTINE
+    sty    hexHigh               ;3  @9
+    sta    hexLow                ;3  @12
+    tya
+    tax                          ;2  @14
+    lsr    a                     ;2  @16
+    lsr    a                     ;2  @18   integer divide 1024 (result 0-63)
+
+    cpx    #$A7                  ;2  @20   account for overflow of multiplying 24 from 43,000 ($A7F8) onward,
+    adc    #1                    ;2  @22   we can just round it to $A700, and the divide by 1024 is fine...
+
+    ;at this point we have a number 1-65 that we have to times by 24,
+    ;add to original sum, and Mod 1024 to get a remainder 0-999
+
+
+    sta    temp                  ;3  @25
+    asl    a                     ;2  @27
+    adc    temp                  ;3  @30  x3
+    tay                          ;2  @32
+    lsr    a                     ;2  @34
+    lsr    a                     ;2  @36
+    lsr    a                     ;2  @38
+    lsr    a                     ;2  @40
+    lsr    a                     ;2  @42
+    tax                          ;2  @44
+    tya                          ;2  @46
+    asl    a                     ;2  @48
+    asl    a                     ;2  @50
+    asl    a                     ;2  @52
+    clc                          ;2  @54
+    adc    hexLow                ;3  @57
+    sta    hexLow                ;3  @60
+    txa                          ;2  @62
+    adc    hexHigh               ;3  @65
+    sta    hexHigh               ;3  @68
+    ror    a                     ;2  @70
+    lsr    a                     ;2  @72
+    tay                          ;2  @74    integer divide 1,000 (result 0-65)
+
+    lsr    a                     ;2  @76    split the 1,000 and 10,000 digit
+    tax                          ;2  @78
+    lda    ShiftedBcdTab,x       ;4  @82
+    tax                          ;2  @84
+    rol    a                     ;2  @86
+    and    #$0F                  ;2  @88
+    ora    #ASCII_0_OFFSET
+    sta    decThousands          ;3  @91
+    txa                          ;2  @93
+    lsr    a                     ;2  @95
+    lsr    a                     ;2  @97
+    lsr    a                     ;2  @99
+    ora    #ASCII_0_OFFSET
+    sta    decTenThousands       ;3  @102
+
+    lda    hexLow                ;3  @105
+    cpy    temp                  ;3  @108
+    bmi    _doSubtract           ;2³ @110/111
+    beq    _useZero               ;2³ @112/113
+    adc    #23 + 24              ;2  @114
+_doSubtract
+    sbc    #23                   ;2  @116
+    sta    hexLow                ;3  @119
+_useZero
+    lda    hexHigh               ;3  @122
+    sbc    #0                    ;2  @124
+
+Start100s
+    and    #$03                  ;2  @126
+    tax                          ;2  @128   0,1,2,3
+    cmp    #2                    ;2  @130
+    rol    a                     ;2  @132   0,2,5,7
+    ora    #ASCII_0_OFFSET
+    tay                          ;2  @134   Y = Hundreds digit
+
+    lda    hexLow                ;3  @137
+    adc    Mod100Tab,x           ;4  @141    adding remainder of 256, 512, and 256+512 (all mod 100)
+    bcs    hex_doSub200             ;2³ @143/144
+
+hex_try200
+    cmp    #200                  ;2  @145
+    bcc    hex_try100               ;2³ @147/148
+hex_doSub200
+    iny                          ;2  @149
+    iny                          ;2  @151
+    sbc    #200                  ;2  @153
+hex_try100
+    cmp    #100                  ;2  @155
+    bcc    HexToDec99            ;2³ @157/158
+    iny                          ;2  @159
+    sbc    #100                  ;2  @161
+
+HexToDec99; SUBROUTINE
+    lsr    a                     ;2  @163
+    tax                          ;2  @165
+    lda    ShiftedBcdTab,x       ;4  @169
+    tax                          ;2  @171
+    rol    a                     ;2  @173
+    and    #$0F                  ;2  @175
+    ora    #ASCII_0_OFFSET
+    sta    decOnes               ;3  @178
+    txa                          ;2  @180
+    lsr    a                     ;2  @182
+    lsr    a                     ;2  @184
+    lsr    a                     ;2  @186
+    ora    #ASCII_0_OFFSET
+
+    ; irmen: load X with ones, and store Y and A too, for easy printing afterwards
+    sty  decHundreds
+    sta  decTens
+    ldx  decOnes
+    rts                          ;6  @192   Y=hundreds, A = tens digit, X=ones digit
+
+
+HexToDec999; SUBROUTINE
+    sty    hexLow                ;3  @9
+    jmp    Start100s             ;3  @12
+
+Mod100Tab
+    .byte 0,56,12,56+12
+
+ShiftedBcdTab
+    .byte $00,$01,$02,$03,$04,$08,$09,$0A,$0B,$0C
+    .byte $10,$11,$12,$13,$14,$18,$19,$1A,$1B,$1C
+    .byte $20,$21,$22,$23,$24,$28,$29,$2A,$2B,$2C
+    .byte $30,$31,$32,$33,$34,$38,$39,$3A,$3B,$3C
+    .byte $40,$41,$42,$43,$44,$48,$49,$4A,$4B,$4C
+
+decTenThousands   	.byte  0
+decThousands    	.byte  0
+decHundreds		.byte  0
+decTens			.byte  0
+decOnes   		.byte  0
+			.byte  0		; zero-terminate the decimal output string
+
+    }}
+}
+
+
+; ----- utility functions ----
+
+
+asmsub  byte2decimal  (byte value @ A) -> ubyte @ Y, ubyte @ A, ubyte @ X  {
+	; ---- A (signed byte) to decimal string in Y/A/X  (100s in Y, 10s in A, 1s in X)
+	;      note: if the number is negative, you have to deal with the '-' yourself!
+	%asm {{
+		cmp  #0
+		bpl  +
+		eor  #255
+		clc
+		adc  #1
++		jmp  ubyte2decimal
+	}}
+}
+
+asmsub  ubyte2hex  (ubyte value @ A) -> ubyte @ A, ubyte @ Y  {
+	; ---- A to hex petscii string in AY (first hex char in A, second hex char in Y)
+	%asm {{
+		stx  P8ZP_SCRATCH_REG
+		pha
+		and  #$0f
+		tax
+		ldy  _hex_digits,x
+		pla
+		lsr  a
+		lsr  a
+		lsr  a
+		lsr  a
+		tax
+		lda  _hex_digits,x
+		ldx  P8ZP_SCRATCH_REG
+		rts
+
+_hex_digits	.text "0123456789abcdef"	; can probably be reused for other stuff as well
+	}}
+}
+
+asmsub  uword2hex  (uword value @ AY) clobbers(A,Y)  {
+	; ---- convert 16 bit uword in A/Y into 4-character hexadecimal string 'uword2hex.output' (0-terminated)
+	%asm {{
+		sta  P8ZP_SCRATCH_REG
+		tya
+		jsr  ubyte2hex
+		sta  output
+		sty  output+1
+		lda  P8ZP_SCRATCH_REG
+		jsr  ubyte2hex
+		sta  output+2
+		sty  output+3
+		rts
+output	.text  "0000", $00      ; 0-terminated output buffer (to make printing easier)
+	}}
+}
+
+
+asmsub  str2ubyte(str string @ AY) clobbers(Y) -> ubyte @A {
+	; -- returns the unsigned byte value of the string number argument in AY
+	;    the number may NOT be preceded by a + sign and may NOT contain spaces
+	;    (any non-digit character will terminate the number string that is parsed)
+	%asm {{
+    	jmp  str2uword
+	}}
+}
+
+asmsub  str2byte(str string @ AY) clobbers(Y) -> ubyte @A {
+	; -- returns the signed byte value of the string number argument in AY
+	;    the number may be preceded by a + or - sign but may NOT contain spaces
+	;    (any non-digit character will terminate the number string that is parsed)
+	%asm {{
+    	jmp  str2word
+	}}
+}
+
+asmsub  str2uword(str string @ AY) -> uword @ AY {
+	; -- returns the unsigned word value of the string number argument in AY
+	;    the number may NOT be preceded by a + sign and may NOT contain spaces
+	;    (any non-digit character will terminate the number string that is parsed)
+	%asm {{
+_result = P8ZP_SCRATCH_W2
+		sta  _mod+1
+		sty  _mod+2
+		ldy  #0
+		sty  _result
+		sty  _result+1
+_mod		lda  $ffff,y		; modified
+		sec
+		sbc  #48
+		bpl  +
+_done		; return result
+		lda  _result
+		ldy  _result+1
+		rts
++		cmp  #10
+		bcs  _done
+		; add digit to result
+		pha
+		jsr  _result_times_10
+		pla
+		clc
+		adc  _result
+		sta  _result
+		bcc  +
+		inc  _result+1
++		iny
+		bne  _mod
+		; never reached
+
+_result_times_10     ; (W*4 + W)*2
+		lda  _result+1
+		sta  P8ZP_SCRATCH_REG
+		lda  _result
+		asl  a
+		rol  P8ZP_SCRATCH_REG
+		asl  a
+		rol  P8ZP_SCRATCH_REG
+		clc
+		adc  _result
+		sta  _result
+		lda  P8ZP_SCRATCH_REG
+		adc  _result+1
+		asl  _result
+		rol  a
+		sta  _result+1
+		rts
+	}}
+}
+
+asmsub  str2word(str string @ AY) -> word @ AY {
+	; -- returns the signed word value of the string number argument in AY
+	;    the number may be preceded by a + or - sign but may NOT contain spaces
+	;    (any non-digit character will terminate the number string that is parsed)
+	%asm {{
+_result = P8ZP_SCRATCH_W2
+		sta  P8ZP_SCRATCH_W1
+		sty  P8ZP_SCRATCH_W1+1
+		ldy  #0
+		sty  _result
+		sty  _result+1
+		sty  _negative
+		lda  (P8ZP_SCRATCH_W1),y
+		cmp  #'+'
+		bne  +
+		iny
++		cmp  #'-'
+		bne  _parse
+		inc  _negative
+		iny
+_parse		lda  (P8ZP_SCRATCH_W1),y
+		sec
+		sbc  #48
+		bpl  _digit
+_done		; return result
+		lda  _negative
+		beq  +
+		sec
+		lda  #0
+		sbc  _result
+		sta  _result
+		lda  #0
+		sbc  _result+1
+		sta  _result+1
++		lda  _result
+		ldy  _result+1
+		rts
+_digit		cmp  #10
+		bcs  _done
+		; add digit to result
+		pha
+		jsr  str2uword._result_times_10
+		pla
+		clc
+		adc  _result
+		sta  _result
+		bcc  +
+		inc  _result+1
++		iny
+		bne  _parse
+		; never reached
+_negative	.byte  0
+	}}
+}
+
+asmsub  hex2uword(str string @ AY) -> uword @AY {
+    ; -- hexadecimal string with or without '$' to uword.
+    ;    string may be in petscii or c64-screencode encoding.
+    %asm {{
+        sta  P8ZP_SCRATCH_W2
+        sty  P8ZP_SCRATCH_W2+1
+        ldy  #0
+        sty  P8ZP_SCRATCH_W1
+        sty  P8ZP_SCRATCH_W1+1
+_loop       ldy  #0
+        sty  P8ZP_SCRATCH_B1
+        lda  (P8ZP_SCRATCH_W2),y
+        beq  _stop
+        cmp  #'$'
+        beq  _skip
+        cmp  #7
+        bcc  _add_nine
+        cmp  #'9'
+        beq  _calc
+        bcs  _add_nine
+_calc       asl  P8ZP_SCRATCH_W1
+        rol  P8ZP_SCRATCH_W1+1
+        asl  P8ZP_SCRATCH_W1
+        rol  P8ZP_SCRATCH_W1+1
+        asl  P8ZP_SCRATCH_W1
+        rol  P8ZP_SCRATCH_W1+1
+        asl  P8ZP_SCRATCH_W1
+        rol  P8ZP_SCRATCH_W1+1
+        and  #$0f
+        clc
+        adc  P8ZP_SCRATCH_B1
+        ora  P8ZP_SCRATCH_W1
+        sta  P8ZP_SCRATCH_W1
+_skip       inc  P8ZP_SCRATCH_W2
+        bne  _loop
+        inc  P8ZP_SCRATCH_W2+1
+        bne  _loop
+_stop       lda  P8ZP_SCRATCH_W1
+        ldy  P8ZP_SCRATCH_W1+1
+        rts
+_add_nine   ldy  #9
+        sty  P8ZP_SCRATCH_B1
+        bne  _calc
+    }}
+}
+
+asmsub  bin2uword(str string @ AY) -> uword @AY {
+    ; -- binary string with or without '%' to uword.
+    %asm {{
+        sta  P8ZP_SCRATCH_W2
+        sty  P8ZP_SCRATCH_W2+1
+        ldy  #0
+        sty  P8ZP_SCRATCH_W1
+        sty  P8ZP_SCRATCH_W1+1
+_loop       lda  (P8ZP_SCRATCH_W2),y
+        beq  _stop
+        cmp  #'%'
+        beq  +
+        asl  P8ZP_SCRATCH_W1
+        rol  P8ZP_SCRATCH_W1+1
+        and  #1
+        ora  P8ZP_SCRATCH_W1
+        sta  P8ZP_SCRATCH_W1
++           inc  P8ZP_SCRATCH_W2
+        bne  _loop
+        inc  P8ZP_SCRATCH_W2+1
+        bne  _loop
+_stop       lda  P8ZP_SCRATCH_W1
+        ldy  P8ZP_SCRATCH_W1+1
+        rts
+    }}
+}
+
+}

compiler/res/prog8lib/cx16/floats.p8

@@ -0,0 +1,154 @@
+; 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
+
+%target cx16
+%option enable_floats
+
+floats {
+	; ---- this block contains C-64 floating point related functions ----
+
+        const float  PI     = 3.141592653589793
+        const float  TWOPI  = 6.283185307179586
+
+
+; ---- ROM float functions ----
+
+		; note: the fac1 and fac2 are working registers and take 6 bytes each,
+		; floats in memory  (and rom) are stored in 5-byte MFLPT packed format.
+
+; note: fac1/2 might get clobbered even if not mentioned in the function's name.
+; note: for subtraction and division, the left operand is in fac2, the right operand in fac1.
+
+romsub $fe00 = AYINT() clobbers(A,X,Y)          ; fac1-> signed word in 100-101 ($64-$65) MSB FIRST. (might throw ILLEGAL QUANTITY)
+
+; GIVAYF: signed word in Y/A (note different lsb/msb order) -> float in fac1
+; there is also floats.GIVUAYFAY - unsigned word in A/Y (lo/hi) to fac1
+; (tip: use GIVAYFAY to use A/Y input; lo/hi switched to normal order)
+romsub $fe03 = GIVAYF(ubyte lo @ Y, ubyte hi @ A) clobbers(A,X,Y)
+
+; fac1 -> unsigned word in Y/A (might throw ILLEGAL QUANTITY) (result also in $14/15)
+; (tip: use GETADRAY to get A/Y output; lo/hi switched to normal little endian order)
+romsub $fe06 = GETADR() clobbers(X) -> ubyte @ Y, ubyte @ A
+
+romsub $fe09 = FADDH() clobbers(A,X,Y)                      ; fac1 += 0.5, for rounding- call this before INT
+romsub $fe0c = FSUB(uword mflpt @ AY) clobbers(A,X,Y)       ; fac1 = mflpt from A/Y - fac1
+romsub $fe0f = FSUBT() clobbers(A,X,Y)                      ; fac1 = fac2-fac1   mind the order of the operands
+romsub $fe12 = FADD(uword mflpt @ AY) clobbers(A,X,Y)       ; fac1 += mflpt value from A/Y
+romsub $fe15 = FADDT() clobbers(A,X,Y)                      ; fac1 += fac2
+romsub $fe1b = ZEROFC() clobbers(A,X,Y)                     ; fac1 = 0
+romsub $fe1e = NORMAL() clobbers(A,X,Y)                     ; normalize fac1 (?)
+romsub $fe24 = LOG() clobbers(A,X,Y)                        ; fac1 = LN(fac1)  (natural log)
+romsub $fe27 = FMULT(uword mflpt @ AY) clobbers(A,X,Y)      ; fac1 *= mflpt value from A/Y
+romsub $fe2a = FMULTT() clobbers(A,X,Y)                     ; fac1 *= fac2
+romsub $fe33 = CONUPK(uword mflpt @ AY) clobbers(A,Y)       ; load mflpt value from memory  in A/Y into fac2
+romsub $fe36 = MUL10() clobbers(A,X,Y)                      ; fac1 *= 10
+romsub $fe3c = DIV10() clobbers(A,X,Y)                      ; fac1 /= 10 , CAUTION: result is always positive!
+romsub $fe3f = FDIV(uword mflpt @ AY) clobbers(A,X,Y)       ; fac1 = mflpt in A/Y / fac1  (remainder in fac2)
+romsub $fe42 = FDIVT() clobbers(A,X,Y)                      ; fac1 = fac2/fac1  (remainder in fac2)  mind the order of the operands
+
+romsub $fe48 = MOVFM(uword mflpt @ AY) clobbers(A,Y)        ; load mflpt value from memory  in A/Y into fac1
+romsub $fe4b = MOVMF(uword mflpt @ XY) clobbers(A,Y)        ; store fac1 to memory  X/Y as 5-byte mflpt
+romsub $fe4e = MOVFA() clobbers(A,X)                        ; copy fac2 to fac1
+romsub $fe51 = MOVAF() clobbers(A,X)                        ; copy fac1 to fac2  (rounded)
+romsub $fe54 = MOVEF() clobbers(A,X)                        ; copy fac1 to fac2
+romsub $fe5a = SIGN() -> ubyte @ A                          ; SIGN(fac1) to A, $ff, $0, $1 for negative, zero, positive
+romsub $fe5d = SGN() clobbers(A,X,Y)                        ; fac1 = SGN(fac1), result of SIGN (-1, 0 or 1)
+romsub $fe60 = FREADSA(byte value @ A) clobbers(A,X,Y)      ; 8 bit signed A -> float in fac1
+romsub $fe6c = ABS()                                        ; fac1 = ABS(fac1)
+romsub $fe6f = FCOMP(uword mflpt @ AY) clobbers(X,Y) -> ubyte @ A   ; A = compare fac1 to mflpt in A/Y, 0=equal 1=fac1 is greater, 255=fac1 is less than
+romsub $fe78 = INT() clobbers(A,X,Y)                        ; INT() truncates, use FADDH first to round instead of trunc
+romsub $fe7e = FINLOG(byte value @A) clobbers (A, X, Y)           ; fac1 += signed byte in A
+romsub $fe81 = FOUT() clobbers(X) -> uword @ AY             ; fac1 -> string, address returned in AY
+romsub $fe8a = SQR() clobbers(A,X,Y)                        ; fac1 = SQRT(fac1)
+romsub $fe8d = FPWRT() clobbers(A,X,Y)                      ; fac1 = fac2 ** fac1
+romsub $fe93 = NEGOP() clobbers(A)                          ; switch the sign of fac1
+romsub $fe96 = EXP() clobbers(A,X,Y)                        ; fac1 = EXP(fac1)  (e ** fac1)
+romsub $fe9f = RND2(byte value @A) clobbers(A,X,Y)                ; fac1 = RND(A) float random number generator
+romsub $fea2 = RND() clobbers(A,X,Y)                        ; fac1 = RND(fac1) float random number generator
+romsub $fea5 = COS() clobbers(A,X,Y)                        ; fac1 = COS(fac1)
+romsub $fea8 = SIN() clobbers(A,X,Y)                        ; fac1 = SIN(fac1)
+romsub $feab = TAN() clobbers(A,X,Y)                        ; fac1 = TAN(fac1)
+romsub $feae = ATN() clobbers(A,X,Y)                        ; fac1 = ATN(fac1)
+
+
+asmsub  GIVUAYFAY  (uword value @ AY) clobbers(A,X,Y)  {
+	; ---- unsigned 16 bit word in A/Y (lo/hi) to fac1
+	%asm {{
+        phx
+        sta  P8ZP_SCRATCH_W2
+        sty  P8ZP_SCRATCH_B1
+        tya
+        ldy  P8ZP_SCRATCH_W2
+        jsr  GIVAYF                 ; load it as signed... correct afterwards
+        lda  P8ZP_SCRATCH_B1
+	    bpl  +
+	    lda  #<_flt65536
+	    ldy  #>_flt65536
+	    jsr  FADD
++	    plx
+        rts
+_flt65536    .byte 145,0,0,0,0       ; 65536.0
+	}}
+}
+
+
+asmsub  GIVAYFAY  (uword value @ AY) clobbers(A,X,Y)  {
+	; ---- signed 16 bit word in A/Y (lo/hi) to float in fac1
+	%asm {{
+		sta  P8ZP_SCRATCH_W2
+		tya
+		ldy  P8ZP_SCRATCH_W2
+		jmp  GIVAYF		; this uses the inverse order, Y/A
+	}}
+}
+
+asmsub  FTOSWRDAY  () clobbers(X) -> uword @ AY  {
+	; ---- fac1 to signed word in A/Y
+	%asm {{
+		jsr  FTOSWORDYA	; note the inverse Y/A order
+		sta  P8ZP_SCRATCH_REG
+		tya
+		ldy  P8ZP_SCRATCH_REG
+		rts
+	}}
+}
+
+asmsub  GETADRAY  () clobbers(X) -> uword @ AY  {
+	; ---- fac1 to unsigned word in A/Y
+	%asm {{
+		jsr  GETADR		; this uses the inverse order, Y/A
+		sta  P8ZP_SCRATCH_B1
+		tya
+		ldy  P8ZP_SCRATCH_B1
+		rts
+	}}
+}
+
+sub  print_f  (float value) {
+	; ---- prints the floating point value (without a newline).
+	%asm {{
+		phx
+		lda  #<value
+		ldy  #>value
+		jsr  MOVFM		; load float into fac1
+		jsr  FOUT		; fac1 to string in A/Y
+		sta  P8ZP_SCRATCH_W1
+		sty  P8ZP_SCRATCH_W1+1
+		ldy  #0
+-		lda  (P8ZP_SCRATCH_W1),y
+		beq  +
+		jsr  c64.CHROUT
+		iny
+		bne  -
++		plx
+		rts
+	}}
+}
+
+%asminclude "library:c64/floats.asm", ""
+%asminclude "library:c64/floats_funcs.asm", ""
+
+}

compiler/res/prog8lib/cx16/graphics.p8

@@ -0,0 +1,164 @@
+%target cx16
+%import syslib
+%import textio
+
+; bitmap pixel graphics module for the CommanderX16
+; wraps the graphics functions that are in ROM.
+; only black/white monchrome 320x200 for now.
+
+graphics {
+    const uword WIDTH = 320
+    const ubyte HEIGHT = 200
+
+    sub enable_bitmap_mode() {
+        ; enable bitmap screen, erase it and set colors to black/white.
+        void cx16.screen_set_mode($80)
+        cx16.r0 = 0
+        cx16.GRAPH_init()
+        clear_screen(1, 0)
+    }
+
+    sub disable_bitmap_mode() {
+        ; enables text mode, erase the text screen, color white
+        void cx16.screen_set_mode(2)
+        txt.fill_screen(' ', 1)     ; TODO doesn't seem to fully clear the text screen after returning from gfx mode
+    }
+
+
+    sub clear_screen(ubyte pixelcolor, ubyte bgcolor) {
+        cx16.GRAPH_set_colors(pixelcolor, pixelcolor, bgcolor)
+        cx16.GRAPH_clear()
+    }
+
+    sub line(uword @zp x1, ubyte @zp y1, uword @zp x2, ubyte @zp y2) {
+        cx16.r0 = x1
+        cx16.r1 = y1
+        cx16.r2 = x2
+        cx16.r3 = y2
+        cx16.GRAPH_draw_line()
+    }
+
+    sub circle(uword xcenter, ubyte ycenter, ubyte radius) {
+        ;cx16.r0 = xcenter - radius/2
+        ;cx16.r1 = ycenter - radius/2
+        ;cx16.r2 = radius*2
+        ;cx16.r3 = radius*2
+        ;cx16.GRAPH_draw_oval(false)          ; TODO  currently is not implemented on cx16, does a BRK
+
+        ; Midpoint algorithm
+        ubyte @zp xx = radius
+        ubyte @zp yy = 0
+        byte @zp decisionOver2 = 1-xx as byte
+
+        while xx>=yy {
+            cx16.r0 = xcenter + xx
+            cx16.r1 = ycenter + yy
+            cx16.FB_cursor_position()
+            cx16.FB_set_pixel(1)
+            cx16.r0 = xcenter - xx
+            cx16.FB_cursor_position()
+            cx16.FB_set_pixel(1)
+            cx16.r0 = xcenter + xx
+            cx16.r1 = ycenter - yy
+            cx16.FB_cursor_position()
+            cx16.FB_set_pixel(1)
+            cx16.r0 = xcenter - xx
+            cx16.FB_cursor_position()
+            cx16.FB_set_pixel(1)
+            cx16.r0 = xcenter + yy
+            cx16.r1 = ycenter + xx
+            cx16.FB_cursor_position()
+            cx16.FB_set_pixel(1)
+            cx16.r0 = xcenter - yy
+            cx16.FB_cursor_position()
+            cx16.FB_set_pixel(1)
+            cx16.r0 = xcenter + yy
+            cx16.r1 = ycenter - xx
+            cx16.FB_cursor_position()
+            cx16.FB_set_pixel(1)
+            cx16.r0 = xcenter - yy
+            cx16.FB_cursor_position()
+            cx16.FB_set_pixel(1)
+            yy++
+            if decisionOver2<=0 {
+                decisionOver2 += 2*yy+1
+            } else {
+                xx--
+                decisionOver2 += 2*(yy-xx)+1
+            }
+        }
+    }
+
+    sub disc(uword xcenter, ubyte ycenter, ubyte radius) {
+;        cx16.r0 = xcenter - radius/2
+;        cx16.r1 = ycenter - radius/2
+;        cx16.r2 = radius*2
+;        cx16.r3 = radius*2
+;        cx16.GRAPH_draw_oval(true)          ; TODO  currently is not implemented on cx16, does a BRK
+
+        ubyte xx = radius
+        ubyte yy = 0
+        byte decisionOver2 = 1-xx as byte
+
+        while xx>=yy {
+            ubyte ycenter_plus_yy = ycenter + yy
+            ubyte ycenter_min_yy = ycenter - yy
+            ubyte ycenter_plus_xx = ycenter + xx
+            ubyte ycenter_min_xx = ycenter - xx
+            uword @zp plotx
+
+            for plotx in xcenter to xcenter+xx {
+                cx16.r0 = plotx
+                cx16.r1 = ycenter_plus_yy
+                cx16.FB_cursor_position()
+                cx16.FB_set_pixel(1)
+                cx16.r1 = ycenter_min_yy
+                cx16.FB_cursor_position()
+                cx16.FB_set_pixel(1)
+            }
+            for plotx in xcenter-xx to xcenter-1 {
+                cx16.r0 = plotx
+                cx16.r1 = ycenter_plus_yy
+                cx16.FB_cursor_position()
+                cx16.FB_set_pixel(1)
+                cx16.r1 = ycenter_min_yy
+                cx16.FB_cursor_position()
+                cx16.FB_set_pixel(1)
+            }
+            for plotx in xcenter to xcenter+yy {
+                cx16.r0 = plotx
+                cx16.r1 = ycenter_plus_xx
+                cx16.FB_cursor_position()
+                cx16.FB_set_pixel(1)
+                cx16.r1 = ycenter_min_xx
+                cx16.FB_cursor_position()
+                cx16.FB_set_pixel(1)
+            }
+            for plotx in xcenter-yy to xcenter {
+                cx16.r0 = plotx
+                cx16.r1 = ycenter_plus_xx
+                cx16.FB_cursor_position()
+                cx16.FB_set_pixel(1)
+                cx16.r1 = ycenter_min_xx
+                cx16.FB_cursor_position()
+                cx16.FB_set_pixel(1)
+            }
+            yy++
+            if decisionOver2<=0
+                decisionOver2 += 2*yy+1
+            else {
+                xx--
+                decisionOver2 += 2*(yy-xx)+1
+            }
+        }
+    }
+
+    sub  plot(uword plotx, ubyte ploty) {
+        cx16.r0 = plotx
+        cx16.r1 = ploty
+        cx16.FB_cursor_position()
+        cx16.FB_set_pixel(1)
+    }
+}
+
+

compiler/res/prog8lib/cx16/syslib.p8

@@ -0,0 +1,291 @@
+; 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
+
+%target cx16
+
+
+c64 {
+
+; ---- kernal routines, these are the same as on the Commodore-64 (hence the same block name) ----
+
+; STROUT --> use txt.print
+; CLEARSCR -> use txt.clear_screen
+; HOMECRSR -> use txt.plot
+
+romsub $FF81 = CINT() clobbers(A,X,Y)                           ; (alias: SCINIT) initialize screen editor and video chip
+romsub $FF84 = IOINIT() clobbers(A, X)                          ; initialize I/O devices (CIA, SID, IRQ)
+romsub $FF87 = RAMTAS() clobbers(A,X,Y)                         ; initialize RAM, tape buffer, screen
+romsub $FF8A = RESTOR() clobbers(A,X,Y)                         ; restore default I/O vectors
+romsub $FF8D = VECTOR(uword userptr @ XY, ubyte dir @ Pc) clobbers(A,Y)     ; read/set I/O vector table
+romsub $FF90 = SETMSG(ubyte value @ A)                          ; set Kernal message control flag
+romsub $FF93 = SECOND(ubyte address @ A) clobbers(A)            ; (alias: LSTNSA) send secondary address after LISTEN
+romsub $FF96 = TKSA(ubyte address @ A) clobbers(A)              ; (alias: TALKSA) send secondary address after TALK
+romsub $FF99 = MEMTOP(uword address @ XY, ubyte dir @ Pc) -> uword @ XY     ; read/set top of memory  pointer
+romsub $FF9C = MEMBOT(uword address @ XY, ubyte dir @ Pc) -> uword @ XY     ; read/set bottom of memory  pointer
+romsub $FF9F = SCNKEY() clobbers(A,X,Y)                         ; scan the keyboard
+romsub $FFA2 = SETTMO(ubyte timeout @ A)                        ; set time-out flag for IEEE bus
+romsub $FFA5 = ACPTR() -> ubyte @ A                             ; (alias: IECIN) input byte from serial bus
+romsub $FFA8 = CIOUT(ubyte databyte @ A)                        ; (alias: IECOUT) output byte to serial bus
+romsub $FFAB = UNTLK() clobbers(A)                              ; command serial bus device to UNTALK
+romsub $FFAE = UNLSN() clobbers(A)                              ; command serial bus device to UNLISTEN
+romsub $FFB1 = LISTEN(ubyte device @ A) clobbers(A)             ; command serial bus device to LISTEN
+romsub $FFB4 = TALK(ubyte device @ A) clobbers(A)               ; command serial bus device to TALK
+romsub $FFB7 = READST() -> ubyte @ A                            ; read I/O status word
+romsub $FFBA = SETLFS(ubyte logical @ A, ubyte device @ X, ubyte address @ Y)   ; set logical file parameters
+romsub $FFBD = SETNAM(ubyte namelen @ A, str filename @ XY)     ; set filename parameters
+romsub $FFC0 = OPEN() clobbers(X,Y) -> ubyte @Pc, ubyte @A      ; (via 794 ($31A)) open a logical file
+romsub $FFC3 = CLOSE(ubyte logical @ A) clobbers(A,X,Y)         ; (via 796 ($31C)) close a logical file
+romsub $FFC6 = CHKIN(ubyte logical @ X) clobbers(A,X) -> ubyte @Pc    ; (via 798 ($31E)) define an input channel
+romsub $FFC9 = CHKOUT(ubyte logical @ X) clobbers(A,X)          ; (via 800 ($320)) define an output channel
+romsub $FFCC = CLRCHN() clobbers(A,X)                           ; (via 802 ($322)) restore default devices
+romsub $FFCF = CHRIN() clobbers(X, Y) -> ubyte @ A   ; (via 804 ($324)) input a character (for keyboard, read a whole line from the screen) A=byte read.
+romsub $FFD2 = CHROUT(ubyte char @ A)                           ; (via 806 ($326)) output a character
+romsub $FFD5 = LOAD(ubyte verify @ A, uword address @ XY) -> ubyte @Pc, ubyte @ A, ubyte @ X, ubyte @ Y     ; (via 816 ($330)) load from device
+romsub $FFD8 = SAVE(ubyte zp_startaddr @ A, uword endaddr @ XY) -> ubyte @ Pc, ubyte @ A                    ; (via 818 ($332)) save to a device
+romsub $FFDB = SETTIM(ubyte low @ A, ubyte middle @ X, ubyte high @ Y)      ; set the software clock
+romsub $FFDE = RDTIM() -> ubyte @ A, ubyte @ X, ubyte @ Y       ; read the software clock
+romsub $FFE1 = STOP() clobbers(X) -> ubyte @ Pz, ubyte @ A      ; (via 808 ($328)) check the STOP key (and some others in A)
+romsub $FFE4 = GETIN() clobbers(X,Y) -> ubyte @Pc, ubyte @ A    ; (via 810 ($32A)) get a character
+romsub $FFE7 = CLALL() clobbers(A,X)                            ; (via 812 ($32C)) close all files
+romsub $FFEA = UDTIM() clobbers(A,X)                            ; update the software clock
+romsub $FFED = SCREEN() -> ubyte @ X, ubyte @ Y                 ; read number of screen rows and columns
+romsub $FFF0 = PLOT(ubyte col @ Y, ubyte row @ X, ubyte dir @ Pc) -> ubyte @ X, ubyte @ Y       ; read/set position of cursor on screen.  Use txt.plot for a 'safe' wrapper that preserves X.
+romsub $FFF3 = IOBASE() -> uword @ XY                           ; read base address of I/O devices
+
+}
+
+cx16 {
+
+; 65c02 hardware vectors:
+    &uword  NMI_VEC         = $FFFA     ; 6502 nmi vector, determined by the kernal if banked in
+    &uword  RESET_VEC       = $FFFC     ; 6502 reset vector, determined by the kernal if banked in
+    &uword  IRQ_VEC         = $FFFE     ; 6502 interrupt vector, determined by the kernal if banked in
+
+
+; the sixteen virtual 16-bit registers
+    &uword r0  = $0002
+    &uword r1  = $0004
+    &uword r2  = $0006
+    &uword r3  = $0008
+    &uword r4  = $000a
+    &uword r5  = $000c
+    &uword r6  = $000e
+    &uword r7  = $0010
+    &uword r8  = $0012
+    &uword r9  = $0014
+    &uword r10 = $0016
+    &uword r11 = $0018
+    &uword r12 = $001a
+    &uword r13 = $001c
+    &uword r14 = $001e
+    &uword r15 = $0020
+
+; VERA registers
+
+    const uword VERA_BASE = $9F20
+    &ubyte  VERA_ADDR_L   	  = VERA_BASE + $0000
+    &ubyte  VERA_ADDR_M   	  = VERA_BASE + $0001
+    &ubyte  VERA_ADDR_H   	  = VERA_BASE + $0002
+    &ubyte  VERA_DATA0        = VERA_BASE + $0003
+    &ubyte  VERA_DATA1        = VERA_BASE + $0004
+    &ubyte  VERA_CTRL         = VERA_BASE + $0005
+    &ubyte  VERA_IEN          = VERA_BASE + $0006
+    &ubyte  VERA_ISR          = VERA_BASE + $0007
+    &ubyte  VERA_IRQ_LINE_L   = VERA_BASE + $0008
+    &ubyte  VERA_DC_VIDEO     = VERA_BASE + $0009
+    &ubyte  VERA_DC_HSCALE    = VERA_BASE + $000A
+    &ubyte  VERA_DC_VSCALE    = VERA_BASE + $000B
+    &ubyte  VERA_DC_BORDER    = VERA_BASE + $000C
+    &ubyte  VERA_DC_HSTART    = VERA_BASE + $0009
+    &ubyte  VERA_DC_HSTOP     = VERA_BASE + $000A
+    &ubyte  VERA_DC_VSTART    = VERA_BASE + $000B
+    &ubyte  VERA_DC_VSTOP     = VERA_BASE + $000C
+    &ubyte  VERA_L0_CONFIG    = VERA_BASE + $000D
+    &ubyte  VERA_L0_MAPBASE   = VERA_BASE + $000E
+    &ubyte  VERA_L0_TILEBASE  = VERA_BASE + $000F
+    &ubyte  VERA_L0_HSCROLL_L = VERA_BASE + $0010
+    &ubyte  VERA_L0_HSCROLL_H = VERA_BASE + $0011
+    &ubyte  VERA_L0_VSCROLL_L = VERA_BASE + $0012
+    &ubyte  VERA_L0_VSCROLL_H = VERA_BASE + $0013
+    &ubyte  VERA_L1_CONFIG    = VERA_BASE + $0014
+    &ubyte  VERA_L1_MAPBASE   = VERA_BASE + $0015
+    &ubyte  VERA_L1_TILEBASE  = VERA_BASE + $0016
+    &ubyte  VERA_L1_HSCROLL_L = VERA_BASE + $0017
+    &ubyte  VERA_L1_HSCROLL_H = VERA_BASE + $0018
+    &ubyte  VERA_L1_VSCROLL_L = VERA_BASE + $0019
+    &ubyte  VERA_L1_VSCROLL_H = VERA_BASE + $001A
+    &ubyte  VERA_AUDIO_CTRL   = VERA_BASE + $001B
+    &ubyte  VERA_AUDIO_RATE   = VERA_BASE + $001C
+    &ubyte  VERA_AUDIO_DATA   = VERA_BASE + $001D
+    &ubyte  VERA_SPI_DATA     = VERA_BASE + $001E
+    &ubyte  VERA_SPI_CTRL     = VERA_BASE + $001F
+; VERA_PSG_BASE     = $1F9C0
+; VERA_PALETTE_BASE = $1FA00
+; VERA_SPRITES_BASE = $1FC00
+
+; I/O
+
+    const uword  via1  = $9f60                  ;VIA 6522 #1
+    &ubyte  d1prb	= via1+0
+    &ubyte  d1pra	= via1+1
+    &ubyte  d1ddrb	= via1+2
+    &ubyte  d1ddra	= via1+3
+    &ubyte  d1t1l	= via1+4
+    &ubyte  d1t1h	= via1+5
+    &ubyte  d1t1ll	= via1+6
+    &ubyte  d1t1lh	= via1+7
+    &ubyte  d1t2l	= via1+8
+    &ubyte  d1t2h	= via1+9
+    &ubyte  d1sr	= via1+10
+    &ubyte  d1acr	= via1+11
+    &ubyte  d1pcr	= via1+12
+    &ubyte  d1ifr	= via1+13
+    &ubyte  d1ier	= via1+14
+    &ubyte  d1ora	= via1+15
+
+    const uword  via2  = $9f70                  ;VIA 6522 #2
+    &ubyte  d2prb	=via2+0
+    &ubyte  d2pra	=via2+1
+    &ubyte  d2ddrb	=via2+2
+    &ubyte  d2ddra	=via2+3
+    &ubyte  d2t1l	=via2+4
+    &ubyte  d2t1h	=via2+5
+    &ubyte  d2t1ll	=via2+6
+    &ubyte  d2t1lh	=via2+7
+    &ubyte  d2t2l	=via2+8
+    &ubyte  d2t2h	=via2+9
+    &ubyte  d2sr	=via2+10
+    &ubyte  d2acr	=via2+11
+    &ubyte  d2pcr	=via2+12
+    &ubyte  d2ifr	=via2+13
+    &ubyte  d2ier	=via2+14
+    &ubyte  d2ora	=via2+15
+
+
+; ---- Commander X-16 additions on top of C64 kernal routines ----
+; spelling of the names is taken from the Commander X-16 rom sources
+
+; supported C128 additions
+romsub $ff4a = close_all(ubyte device @A)  clobbers(A,X,Y)
+romsub $ff59 = lkupla(ubyte la @A)  clobbers(A,X,Y)
+romsub $ff5c = lkupsa(ubyte sa @Y)  clobbers(A,X,Y)
+romsub $ff5f = screen_set_mode(ubyte mode @A)  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 $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)
+romsub $ff7d = primm()
+
+; X16 additions
+romsub $ff44 = macptr()  clobbers(A,X,Y)
+romsub $ff47 = enter_basic(ubyte cold_or_warm @Pc)  clobbers(A,X,Y)
+romsub $ff68 = mouse_config(ubyte shape @A, ubyte scale @X)  clobbers (A, X, Y)
+romsub $ff6b = mouse_get(ubyte zpdataptr @X)  clobbers(A)
+romsub $ff71 = mouse_scan()  clobbers(A, X, Y)
+romsub $ff53 = joystick_scan()  clobbers(A, X, Y)
+romsub $ff56 = joystick_get(ubyte joynr @A) -> ubyte @A, ubyte @X, ubyte @Y
+romsub $ff4d = clock_set_date_time()  clobbers(A, X, Y)      ; args: r0, r1, r2, r3L
+romsub $ff50 = clock_get_date_time()  clobbers(A, X, Y)      ; outout args: r0, r1, r2, r3L
+
+; TODO specify the correct clobbers for alle these functions below, we now assume all 3 regs are clobbered
+
+; high level graphics & fonts
+romsub $ff20 = GRAPH_init()  clobbers(A,X,Y)           ; uses vectors=r0
+romsub $ff23 = GRAPH_clear()  clobbers(A,X,Y)
+romsub $ff26 = GRAPH_set_window()  clobbers(A,X,Y)      ; uses x=r0, y=r1, width=r2, height=r3
+romsub $ff29 = GRAPH_set_colors(ubyte stroke @A, ubyte fill @X, ubyte background @Y)  clobbers (A,X,Y)
+romsub $ff2c = GRAPH_draw_line()  clobbers(A,X,Y)       ; uses x1=r0, y1=r1, x2=r2, y2=r3
+romsub $ff2f = GRAPH_draw_rect(ubyte fill @Pc)  clobbers(A,X,Y)   ; uses x=r0, y=r1, width=r2, height=r3, cornerradius=r4
+romsub $ff32 = GRAPH_move_rect()  clobbers(A,X,Y)       ; uses sx=r0, sy=r1, tx=r2, ty=r3, width=r4, height=r5
+romsub $ff35 = GRAPH_draw_oval(ubyte fill @Pc)  clobbers(A,X,Y)       ; uses x=r0, y=r1, width=r2, height=r3
+romsub $ff38 = GRAPH_draw_image()  clobbers(A,X,Y)      ; uses x=r0, y=r1, ptr=r2, width=r3, height=r4
+romsub $ff3b = GRAPH_set_font()  clobbers(A,X,Y)         ; uses ptr=r0
+romsub $ff3e = GRAPH_get_char_size(ubyte baseline @A, ubyte width @X, ubyte height_or_style @Y, ubyte is_control @Pc)  clobbers(A,X,Y)
+romsub $ff41 = GRAPH_put_char(ubyte char @A)  clobbers(A,X,Y)   ; uses x=r0, y=r1
+
+; framebuffer
+romsub $fef6 = FB_init()  clobbers(A,X,Y)
+romsub $fef9 = FB_get_info()  clobbers(X,Y) -> byte @A    ; also outputs width=r0, height=r1
+romsub $fefc = FB_set_palette(ubyte index @A, ubyte bytecount @X)  clobbers(A,X,Y)      ; also uses pointer=r0
+romsub $feff = FB_cursor_position()  clobbers(A,X,Y)    ; uses x=r0, y=r1
+romsub $ff02 = FB_cursor_next_line()  clobbers(A,X,Y)   ; uses x=r0
+romsub $ff05 = FB_get_pixel()  clobbers(X,Y) -> ubyte @A
+romsub $ff08 = FB_get_pixels()  clobbers(A,X,Y)         ; uses ptr=r0, count=r1
+romsub $ff0b = FB_set_pixel(ubyte color @A)  clobbers(A,X,Y)
+romsub $ff0e = FB_set_pixels()  clobbers(A,X,Y)         ; uses ptr=r0, count=r1
+romsub $ff11 = FB_set_8_pixels(ubyte pattern @A, ubyte color @X)  clobbers(A,X,Y)
+romsub $ff14 = FB_set_8_pixels_opaque(ubyte pattern @A, ubyte color1 @X, ubyte color2 @Y)  clobbers(A,X,Y)  ; also uses mask=r0L
+romsub $ff17 = FB_fill_pixels(ubyte color @A)  clobbers(A,X,Y)   ; also uses count=r0, step=r1
+romsub $ff1a = FB_filter_pixels()  clobbers(A,X,Y)      ; uses ptr=r0, count=r1
+romsub $ff1d = FB_move_pixels()  clobbers(A,X,Y)        ; uses sx=r0, sy=r1, tx=r2, ty=r3, count=r4
+
+; misc
+romsub $fef0 = sprite_set_image(ubyte number @A, ubyte width @X, ubyte height @Y, ubyte apply_mask @Pc)  clobbers(A,X,Y) -> ubyte @Pc  ; also uses pixels=r0, mask=r1, bpp=r2L
+romsub $fef3 = sprite_set_position(ubyte number @A)  clobbers(A,X,Y)  ; also uses x=r0 and y=r1
+romsub $fee4 = memory_fill(ubyte value @A)  clobbers(A,X,Y)      ; uses address=r0, num_bytes=r1
+romsub $fee7 = memory_copy()  clobbers(A,X,Y)                    ; uses source=r0, target=r1, num_bytes=r2
+romsub $feea = memory_crc()  clobbers(A,X,Y)                     ; uses address=r0, num_bytes=r1     result->r2
+romsub $feed = memory_decompress()  clobbers(A,X,Y)              ; uses input=r0, output=r1     result->r1
+romsub $fedb = console_init()  clobbers(A,X,Y)           ; uses x=r0, y=r1, width=r2, height=r3
+romsub $fede = console_put_char(ubyte char @A, ubyte wrapping @Pc)  clobbers(A,X,Y)
+romsub $fee1 = console_get_char()  clobbers(X,Y) -> ubyte @A
+romsub $fed8 = console_put_image()  clobbers(A,X,Y)      ; uses ptr=r0, width=r1, height=r2
+romsub $fed5 = console_set_paging_message()  clobbers(A,X,Y)     ; uses messageptr=r0
+romsub $fed2 = kbdbuf_put(ubyte key @A)  clobbers(A,X,Y)
+romsub $fecf = entropy_get() -> ubyte @A, ubyte @X, ubyte @Y
+romsub $fecc = monitor()  clobbers(A,X,Y)
+
+
+
+; ---- end of kernal routines ----
+
+asmsub init_system()  {
+    ; Initializes the machine to a sane starting state.
+    ; Called automatically by the loader program logic.
+    %asm {{
+        sei
+        cld
+        ;stz  $00
+        ;stz  $01
+        ;stz  d1prb      ; select rom bank 0
+        lda  #$80
+        sta  VERA_CTRL
+        jsr  c64.IOINIT
+        jsr  c64.RESTOR
+        jsr  c64.CINT
+        lda  #$90       ; black
+        jsr  c64.CHROUT
+        lda  #1         ; swap fg/bg
+        jsr  c64.CHROUT
+        lda  #$9e       ; yellow
+        jsr  c64.CHROUT
+        lda  #147       ; clear screen
+        jsr  c64.CHROUT
+        lda  #0
+        tax
+        tay
+        clc
+        clv
+        cli
+        rts
+    }}
+}
+
+asmsub  reset_system()  {
+    ; Soft-reset the system back to Basic prompt.
+    %asm {{
+        sei
+        lda  #14
+        sta  $01
+        stz  cx16.d1prb         ; bank the kernal in
+        jmp  (cx16.RESET_VEC)
+    }}
+}
+
+}

compiler/res/prog8lib/cx16/textio.p8

@@ -0,0 +1,699 @@
+; 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
+
+%target cx16
+%import syslib
+%import conv
+
+
+txt {
+
+const ubyte DEFAULT_WIDTH = 80
+const ubyte DEFAULT_HEIGHT = 60
+
+
+sub  clear_screen() {
+    clear_screenchars(' ')
+}
+
+asmsub  fill_screen (ubyte char @ A, ubyte color @ Y) clobbers(A)  {
+	; ---- fill the character screen with the given fill character and character color.
+	%asm {{
+	    sty  _ly+1
+        phx
+        pha
+        jsr  c64.SCREEN             ; get dimensions in X/Y
+        txa
+        lsr  a
+        lsr  a
+        sta  _lx+1
+        stz  cx16.VERA_CTRL
+        lda  #%00010000
+        sta  cx16.VERA_ADDR_H       ; enable auto increment by 1, bank 0.
+        stz  cx16.VERA_ADDR_L       ; start at (0,0)
+        stz  cx16.VERA_ADDR_M
+        pla
+_lx     ldx  #0                     ; modified
+        phy
+_ly     ldy  #1                     ; modified
+-       sta  cx16.VERA_DATA0
+        sty  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA0
+        sty  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA0
+        sty  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA0
+        sty  cx16.VERA_DATA0
+        dex
+        bne  -
+        ply
+        dey
+        beq  +
+        stz  cx16.VERA_ADDR_L
+        inc  cx16.VERA_ADDR_M       ; next line
+        bra  _lx
++       plx
+        rts
+        }}
+}
+
+asmsub  clear_screenchars (ubyte char @ A) clobbers(Y)  {
+	; ---- clear the character screen with the given fill character (leaves colors)
+	;      (assumes screen matrix is at the default address)
+	%asm {{
+        phx
+        pha
+        jsr  c64.SCREEN             ; get dimensions in X/Y
+        txa
+        lsr  a
+        lsr  a
+        sta  _lx+1
+        stz  cx16.VERA_CTRL
+        lda  #%00100000
+        sta  cx16.VERA_ADDR_H       ; enable auto increment by 2, bank 0.
+        stz  cx16.VERA_ADDR_L       ; start at (0,0)
+        stz  cx16.VERA_ADDR_M
+        pla
+_lx     ldx  #0                     ; modified
+-       sta  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA0
+        dex
+        bne  -
+        dey
+        beq  +
+        stz  cx16.VERA_ADDR_L
+        inc  cx16.VERA_ADDR_M       ; next line
+        bra  _lx
++       plx
+        rts
+        }}
+}
+
+asmsub  clear_screencolors (ubyte color @ A) clobbers(Y)  {
+	; ---- clear the character screen colors with the given color (leaves characters).
+	;      (assumes color matrix is at the default address)
+	%asm {{
+        phx
+        sta  _la+1
+        jsr  c64.SCREEN             ; get dimensions in X/Y
+        txa
+        lsr  a
+        lsr  a
+        sta  _lx+1
+        stz  cx16.VERA_CTRL
+        lda  #%00100000
+        sta  cx16.VERA_ADDR_H       ; enable auto increment by 2, bank 0.
+        lda  #1
+        sta  cx16.VERA_ADDR_L       ; start at (1,0)
+        stz  cx16.VERA_ADDR_M
+_lx     ldx  #0                     ; modified
+_la     lda  #0                     ; modified
+-       sta  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA0
+        dex
+        bne  -
+        dey
+        beq  +
+        lda  #1
+        sta  cx16.VERA_ADDR_L
+        inc  cx16.VERA_ADDR_M       ; next line
+        bra  _lx
++       plx
+        rts
+        }}
+}
+
+
+ubyte[16] color_to_charcode = [$90,$05,$1c,$9f,$9c,$1e,$1f,$9e,$81,$95,$96,$97,$98,$99,$9a,$9b]
+
+sub color (ubyte txtcol) {
+    txtcol &= 15
+    c64.CHROUT(color_to_charcode[txtcol])
+}
+
+sub color2 (ubyte txtcol, ubyte bgcol) {
+    txtcol &= 15
+    bgcol &= 15
+    c64.CHROUT(color_to_charcode[bgcol])
+    c64.CHROUT(1)       ; switch fg and bg colors
+    c64.CHROUT(color_to_charcode[txtcol])
+}
+
+sub lowercase() {
+    cx16.screen_set_charset(3, 0)  ; lowercase charset
+}
+
+sub uppercase() {
+    cx16.screen_set_charset(2, 0)  ; uppercase charset
+}
+
+asmsub  scroll_left  (ubyte dummy @ Pc) clobbers(A, Y)  {
+	; ---- scroll the whole screen 1 character to the left
+	;      contents of the rightmost column are unchanged, you should clear/refill this yourself
+	;      Carry flag is a dummy on the cx16
+	%asm {{
+	    phx
+	    jsr  c64.SCREEN
+	    dex
+	    stx  _lx+1
+        dey
+        sty  P8ZP_SCRATCH_B1    ; number of rows to scroll
+
+_nextline
+        stz  cx16.VERA_CTRL     ; data port 0: source column
+        lda  #%00010000         ; auto increment 1
+        sta  cx16.VERA_ADDR_H
+        lda  #2
+        sta  cx16.VERA_ADDR_L   ; begin in column 1
+        ldy  P8ZP_SCRATCH_B1
+        sty  cx16.VERA_ADDR_M
+        lda  #1
+        sta  cx16.VERA_CTRL     ; data port 1: destination column
+        lda  #%00010000         ; auto increment 1
+        sta  cx16.VERA_ADDR_H
+        stz  cx16.VERA_ADDR_L
+        sty  cx16.VERA_ADDR_M
+
+_lx     ldx  #0                ; modified
+-       lda  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA1    ; copy char
+        lda  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA1    ; copy color
+        dex
+        bne  -
+        dec  P8ZP_SCRATCH_B1
+        bpl  _nextline
+
+        lda  #0
+        sta  cx16.VERA_CTRL
+	    plx
+	    rts
+	}}
+}
+
+asmsub  scroll_right  (ubyte dummy @ Pc) clobbers(A)  {
+	; ---- scroll the whole screen 1 character to the right
+	;      contents of the leftmost column are unchanged, you should clear/refill this yourself
+	;      Carry flag is a dummy on the cx16
+	%asm {{
+	    phx
+	    jsr  c64.SCREEN
+	    dex
+	    stx  _lx+1
+	    txa
+	    asl  a
+	    dea
+	    sta  _rcol+1
+	    ina
+	    ina
+	    sta  _rcol2+1
+        dey
+        sty  P8ZP_SCRATCH_B1    ; number of rows to scroll
+
+_nextline
+        stz  cx16.VERA_CTRL     ; data port 0: source column
+        lda  #%00011000         ; auto decrement 1
+        sta  cx16.VERA_ADDR_H
+_rcol   lda  #79*2-1             ; modified
+        sta  cx16.VERA_ADDR_L   ; begin in rightmost column minus one
+        ldy  P8ZP_SCRATCH_B1
+        sty  cx16.VERA_ADDR_M
+        lda  #1
+        sta  cx16.VERA_CTRL     ; data port 1: destination column
+        lda  #%00011000         ; auto decrement 1
+        sta  cx16.VERA_ADDR_H
+_rcol2  lda  #79*2+1            ; modified
+        sta  cx16.VERA_ADDR_L
+        sty  cx16.VERA_ADDR_M
+
+_lx     ldx  #0                 ; modified
+-       lda  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA1    ; copy char
+        lda  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA1    ; copy color
+        dex
+        bne  -
+        dec  P8ZP_SCRATCH_B1
+        bpl  _nextline
+
+        lda  #0
+        sta  cx16.VERA_CTRL
+	    plx
+	    rts
+	}}
+}
+
+asmsub  scroll_up  (ubyte dummy @ Pc) clobbers(A, Y)  {
+	; ---- scroll the whole screen 1 character up
+	;      contents of the bottom row are unchanged, you should refill/clear this yourself
+	;      Carry flag is a dummy on the cx16
+	%asm {{
+	    phx
+	    jsr  c64.SCREEN
+	    stx  _nextline+1
+	    dey
+        sty  P8ZP_SCRATCH_B1
+        stz  cx16.VERA_CTRL         ; data port 0 is source
+        lda  #1
+        sta  cx16.VERA_ADDR_M       ; start at second line
+        stz  cx16.VERA_ADDR_L
+        lda  #%00010000
+        sta  cx16.VERA_ADDR_H       ; enable auto increment by 1, bank 0.
+
+        lda  #1
+        sta  cx16.VERA_CTRL         ; data port 1 is destination
+        stz  cx16.VERA_ADDR_M       ; start at top line
+        stz  cx16.VERA_ADDR_L
+        lda  #%00010000
+        sta  cx16.VERA_ADDR_H       ; enable auto increment by 1, bank 0.
+
+_nextline
+        ldx  #80        ; modified
+-       lda  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA1        ; copy char
+        lda  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA1        ; copy color
+        dex
+        bne  -
+        dec  P8ZP_SCRATCH_B1
+        beq  +
+        stz  cx16.VERA_CTRL         ; data port 0
+        stz  cx16.VERA_ADDR_L
+        inc  cx16.VERA_ADDR_M
+        lda  #1
+        sta  cx16.VERA_CTRL         ; data port 1
+        stz  cx16.VERA_ADDR_L
+        inc  cx16.VERA_ADDR_M
+        bra  _nextline
+
++       lda  #0
+        sta  cx16.VERA_CTRL
+	    plx
+	    rts
+	}}
+}
+
+asmsub  scroll_down  (ubyte dummy @ Pc) clobbers(A, Y)  {
+	; ---- scroll the whole screen 1 character down
+	;      contents of the top row are unchanged, you should refill/clear this yourself
+	;      Carry flag is a dummy on the cx16
+	%asm {{
+	    phx
+	    jsr  c64.SCREEN
+	    stx  _nextline+1
+	    dey
+        sty  P8ZP_SCRATCH_B1
+        stz  cx16.VERA_CTRL         ; data port 0 is source
+        dey
+        sty  cx16.VERA_ADDR_M       ; start at line before bottom line
+        stz  cx16.VERA_ADDR_L
+        lda  #%00010000
+        sta  cx16.VERA_ADDR_H       ; enable auto increment by 1, bank 0.
+
+        lda  #1
+        sta  cx16.VERA_CTRL         ; data port 1 is destination
+        iny
+        sty  cx16.VERA_ADDR_M       ; start at bottom line
+        stz  cx16.VERA_ADDR_L
+        lda  #%00010000
+        sta  cx16.VERA_ADDR_H       ; enable auto increment by 1, bank 0.
+
+_nextline
+        ldx  #80        ; modified
+-       lda  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA1        ; copy char
+        lda  cx16.VERA_DATA0
+        sta  cx16.VERA_DATA1        ; copy color
+        dex
+        bne  -
+        dec  P8ZP_SCRATCH_B1
+        beq  +
+        stz  cx16.VERA_CTRL         ; data port 0
+        stz  cx16.VERA_ADDR_L
+        dec  cx16.VERA_ADDR_M
+        lda  #1
+        sta  cx16.VERA_CTRL         ; data port 1
+        stz  cx16.VERA_ADDR_L
+        dec  cx16.VERA_ADDR_M
+        bra  _nextline
+
++       lda  #0
+        sta  cx16.VERA_CTRL
+	    plx
+	    rts
+	}}
+}
+
+romsub $FFD2 = chrout(ubyte char @ A)    ; for consistency. You can also use c64.CHROUT directly ofcourse.
+
+asmsub  print (str text @ AY) clobbers(A,Y)  {
+	; ---- print null terminated string from A/Y
+	; note: the compiler contains an optimization that will replace
+	;       a call to this subroutine with a string argument of just one char,
+	;       by just one call to c64.CHROUT of that single char.
+	%asm {{
+		sta  P8ZP_SCRATCH_B1
+		sty  P8ZP_SCRATCH_REG
+		ldy  #0
+-		lda  (P8ZP_SCRATCH_B1),y
+		beq  +
+		jsr  c64.CHROUT
+		iny
+		bne  -
++		rts
+	}}
+}
+
+asmsub  print_ub0  (ubyte value @ A) clobbers(A,Y)  {
+	; ---- print the ubyte in A in decimal form, with left padding 0s (3 positions total)
+	%asm {{
+		phx
+		jsr  conv.ubyte2decimal
+		pha
+		tya
+		jsr  c64.CHROUT
+		pla
+		jsr  c64.CHROUT
+		txa
+		jsr  c64.CHROUT
+		plx
+		rts
+	}}
+}
+
+asmsub  print_ub  (ubyte value @ A) clobbers(A,Y)  {
+	; ---- print the ubyte in A in decimal form, without left padding 0s
+	%asm {{
+		phx
+		jsr  conv.ubyte2decimal
+_print_byte_digits
+		pha
+		cpy  #'0'
+		beq  +
+		tya
+		jsr  c64.CHROUT
+		pla
+		jsr  c64.CHROUT
+		jmp  _ones
++       pla
+        cmp  #'0'
+        beq  _ones
+        jsr  c64.CHROUT
+_ones   txa
+		jsr  c64.CHROUT
+		plx
+		rts
+	}}
+}
+
+asmsub  print_b  (byte value @ A) clobbers(A,Y)  {
+	; ---- print the byte in A in decimal form, without left padding 0s
+	%asm {{
+		phx
+		pha
+		cmp  #0
+		bpl  +
+		lda  #'-'
+		jsr  c64.CHROUT
++		pla
+		jsr  conv.byte2decimal
+		jmp  print_ub._print_byte_digits
+	}}
+}
+
+asmsub  print_ubhex  (ubyte value @ A, ubyte prefix @ Pc) clobbers(A,Y)  {
+	; ---- print the ubyte in A in hex form (if Carry is set, a radix prefix '$' is printed as well)
+	%asm {{
+		phx
+		bcc  +
+		pha
+		lda  #'$'
+		jsr  c64.CHROUT
+		pla
++		jsr  conv.ubyte2hex
+		jsr  c64.CHROUT
+		tya
+		jsr  c64.CHROUT
+		plx
+		rts
+	}}
+}
+
+asmsub  print_ubbin  (ubyte value @ A, ubyte prefix @ Pc) clobbers(A,Y)  {
+	; ---- print the ubyte in A in binary form (if Carry is set, a radix prefix '%' is printed as well)
+	%asm {{
+		phx
+		sta  P8ZP_SCRATCH_B1
+		bcc  +
+		lda  #'%'
+		jsr  c64.CHROUT
++		ldy  #8
+-		lda  #'0'
+		asl  P8ZP_SCRATCH_B1
+		bcc  +
+		lda  #'1'
++		jsr  c64.CHROUT
+		dey
+		bne  -
+		plx
+		rts
+	}}
+}
+
+asmsub  print_uwbin  (uword value @ AY, ubyte prefix @ Pc) clobbers(A,Y)  {
+	; ---- print the uword in A/Y in binary form (if Carry is set, a radix prefix '%' is printed as well)
+	%asm {{
+		pha
+		tya
+		jsr  print_ubbin
+		pla
+		clc
+		jmp  print_ubbin
+	}}
+}
+
+asmsub  print_uwhex  (uword value @ AY, ubyte prefix @ Pc) clobbers(A,Y)  {
+	; ---- print the uword in A/Y in hexadecimal form (4 digits)
+	;      (if Carry is set, a radix prefix '$' is printed as well)
+	%asm {{
+		pha
+		tya
+		jsr  print_ubhex
+		pla
+		clc
+		jmp  print_ubhex
+	}}
+}
+
+asmsub  print_uw0  (uword value @ AY) clobbers(A,Y)  {
+	; ---- print the uword in A/Y in decimal form, with left padding 0s (5 positions total)
+	%asm {{
+	    phx
+		jsr  conv.uword2decimal
+		ldy  #0
+-		lda  conv.uword2decimal.decTenThousands,y
+        beq  +
+		jsr  c64.CHROUT
+		iny
+		bne  -
++		plx
+		rts
+	}}
+}
+
+asmsub  print_uw  (uword value @ AY) clobbers(A,Y)  {
+	; ---- print the uword in A/Y in decimal form, without left padding 0s
+	%asm {{
+	    phx
+		jsr  conv.uword2decimal
+		plx
+		ldy  #0
+-		lda  conv.uword2decimal.decTenThousands,y
+		beq  _allzero
+		cmp  #'0'
+		bne  _gotdigit
+		iny
+		bne  -
+
+_gotdigit
+		jsr  c64.CHROUT
+		iny
+		lda  conv.uword2decimal.decTenThousands,y
+		bne  _gotdigit
+		rts
+_allzero
+        lda  #'0'
+        jmp  c64.CHROUT
+	}}
+}
+
+asmsub  print_w  (word value @ AY) clobbers(A,Y)  {
+	; ---- print the (signed) word in A/Y in decimal form, without left padding 0's
+	%asm {{
+		cpy  #0
+		bpl  +
+		pha
+		lda  #'-'
+		jsr  c64.CHROUT
+		tya
+		eor  #255
+		tay
+		pla
+		eor  #255
+		clc
+		adc  #1
+		bcc  +
+		iny
++		jmp  print_uw
+	}}
+}
+
+asmsub  input_chars  (uword buffer @ AY) clobbers(A) -> ubyte @ Y  {
+	; ---- Input a string (max. 80 chars) from the keyboard. Returns length in Y. (string is terminated with a 0 byte as well)
+	;      It assumes the keyboard is selected as I/O channel!
+
+	%asm {{
+		sta  P8ZP_SCRATCH_W1
+		sty  P8ZP_SCRATCH_W1+1
+		ldy  #0				; char counter = 0
+-		jsr  c64.CHRIN
+		cmp  #$0d			; return (ascii 13) pressed?
+		beq  +				; yes, end.
+		sta  (P8ZP_SCRATCH_W1),y	; else store char in buffer
+		iny
+		bne  -
++		lda  #0
+		sta  (P8ZP_SCRATCH_W1),y	; finish string with 0 byte
+		rts
+
+	}}
+}
+
+asmsub  setchr  (ubyte col @X, ubyte row @Y, ubyte character @A) clobbers(A)  {
+	; ---- sets the character in the screen matrix at the given position
+	%asm {{
+		pha
+		txa
+		asl  a
+        stz  cx16.VERA_CTRL
+		stz  cx16.VERA_ADDR_H
+		sta  cx16.VERA_ADDR_L
+		sty  cx16.VERA_ADDR_M
+		pla
+        sta  cx16.VERA_DATA0
+		rts
+	}}
+}
+
+asmsub  getchr  (ubyte col @A, ubyte row @Y) -> ubyte @ A {
+	; ---- get the character in the screen matrix at the given location
+	%asm  {{
+		asl  a
+        stz  cx16.VERA_CTRL
+		stz  cx16.VERA_ADDR_H
+		sta  cx16.VERA_ADDR_L
+		sty  cx16.VERA_ADDR_M
+        lda  cx16.VERA_DATA0
+		rts
+	}}
+}
+
+asmsub  setclr  (ubyte col @X, ubyte row @Y, ubyte color @A) clobbers(A)  {
+	; ---- set the color in A on the screen matrix at the given position
+	%asm {{
+		pha
+		txa
+		asl  a
+		ina
+        stz  cx16.VERA_CTRL
+		stz  cx16.VERA_ADDR_H
+		sta  cx16.VERA_ADDR_L
+		sty  cx16.VERA_ADDR_M
+		pla
+        sta  cx16.VERA_DATA0
+		rts
+	}}
+}
+
+asmsub  getclr  (ubyte col @A, ubyte row @Y) -> ubyte @ A {
+	; ---- get the color in the screen color matrix at the given location
+	%asm  {{
+		asl  a
+		ina
+        stz  cx16.VERA_CTRL
+		stz  cx16.VERA_ADDR_H
+		sta  cx16.VERA_ADDR_L
+		sty  cx16.VERA_ADDR_M
+        lda  cx16.VERA_DATA0
+		rts
+	}}
+}
+
+sub  setcc  (ubyte column, ubyte row, ubyte char, ubyte charcolor)  {
+	; ---- set char+color at the given position on the screen
+	%asm {{
+	    phx
+		lda  column
+		asl  a
+		tax
+		ldy  row
+		lda  charcolor
+		and  #$0f
+	    sta  P8ZP_SCRATCH_B1
+        stz  cx16.VERA_CTRL
+        stz  cx16.VERA_ADDR_H
+        stx  cx16.VERA_ADDR_L
+        sty  cx16.VERA_ADDR_M
+        lda  char
+        sta  cx16.VERA_DATA0
+        inx
+        stz  cx16.VERA_ADDR_H
+        stx  cx16.VERA_ADDR_L
+        sty  cx16.VERA_ADDR_M
+        lda  cx16.VERA_DATA0
+        and  #$f0
+        ora  P8ZP_SCRATCH_B1
+        sta  cx16.VERA_DATA0
+		plx
+		rts
+    }}
+}
+
+asmsub  plot  (ubyte col @ Y, ubyte row @ A) clobbers(A) {
+	; ---- safe wrapper around PLOT kernel routine, to save the X register.
+	%asm  {{
+		phx
+		tax
+		clc
+		jsr  c64.PLOT
+		plx
+		rts
+	}}
+}
+
+asmsub width() clobbers(X,Y) -> ubyte @A {
+    ; -- returns the text screen width (number of columns)
+    %asm {{
+        jsr  c64.SCREEN
+        txa
+        rts
+    }}
+}
+
+asmsub height() clobbers(X, Y) -> ubyte @A {
+    ; -- returns the text screen height (number of rows)
+    %asm {{
+        jsr  c64.SCREEN
+        tya
+        rts
+    }}
+}
+
+}

compiler/res/prog8lib/cx16logo.p8

@@ -0,0 +1,29 @@
+%import textio
+
+cx16logo {
+    sub logo_at(ubyte column, ubyte row) {
+        uword strptr
+        for strptr in logo_lines {
+            txt.plot(column, row)
+            txt.print(strptr)
+            row++
+        }
+    }
+
+    sub logo() {
+        uword strptr
+        for strptr in logo_lines
+            txt.print(strptr)
+        txt.chrout('\n')
+    }
+
+    str[] logo_lines = [
+            "\uf10d\uf11a\uf139\uf11b     \uf11a\uf13a\uf11b\n",
+            "\uf10b\uf11a▎\uf139\uf11b   \uf11a\uf13a\uf130\uf11b\n",
+            "\uf10f\uf11a▌ \uf139\uf11b \uf11a\uf13a \uf11b▌\n",
+            "\uf102 \uf132\uf11a▖\uf11b \uf11a▗\uf11b\uf132\n",
+            "\uf10e ▂\uf11a▘\uf11b \uf11a▝\uf11b▂\n",
+            "\uf104 \uf11a \uf11b\uf13a\uf11b \uf139\uf11a \uf11b\n",
+            "\uf101\uf130\uf13a   \uf139▎\uf100"
+        ]
+}

compiler/res/prog8lib/diskio.p8

@@ -0,0 +1,162 @@
+%import textio
+%import syslib
+
+; Note: this code is compatible with C64 and CX16.
+
+diskio {
+
+
+    sub directory(ubyte drivenumber) -> byte {
+        ; -- Shows the directory contents of disk drive 8-11 (provide as argument).
+
+        c64.SETNAM(1, "$")
+        c64.SETLFS(1, drivenumber, 0)
+        void c64.OPEN()          ; open 1,8,0,"$"
+        if_cs
+            goto io_error
+        void c64.CHKIN(1)        ; use #1 as input channel
+        if_cs
+            goto io_error
+
+        repeat 4 {
+            void c64.CHRIN()     ; skip the 4 prologue bytes
+        }
+
+        ; while not key pressed / EOF encountered, read data.
+        ubyte status = c64.READST()
+        while not status {
+            txt.print_uw(mkword(c64.CHRIN(), c64.CHRIN()))
+            txt.chrout(' ')
+            ubyte @zp char
+            do {
+                char = c64.CHRIN()
+                txt.chrout(char)
+            } until char==0
+            txt.chrout('\n')
+            void c64.CHRIN()     ; skip 2 bytes
+            void c64.CHRIN()
+            status = c64.READST()
+            void c64.STOP()
+            if_nz
+                break
+        }
+
+io_error:
+        status = c64.READST()
+        c64.CLRCHN()        ; restore default i/o devices
+        c64.CLOSE(1)
+
+        if status and status != 64 {            ; 64=end of file
+            txt.print("\ni/o error, status: ")
+            txt.print_ub(status)
+            txt.chrout('\n')
+            return false
+        }
+
+        return true
+    }
+
+
+    sub status(ubyte drivenumber) {
+        ; -- display the disk drive's current status message
+        c64.SETNAM(0, $0000)
+        c64.SETLFS(15, drivenumber, 15)
+        void c64.OPEN()          ; open 15,8,15
+        if_cs
+            goto io_error
+        void c64.CHKIN(15)        ; use #15 as input channel
+        if_cs
+            goto io_error
+
+        while not c64.READST()
+            txt.chrout(c64.CHRIN())
+
+io_error:
+        c64.CLRCHN()        ; restore default i/o devices
+        c64.CLOSE(15)
+    }
+
+
+    sub save(ubyte drivenumber, uword filenameptr, uword address, uword size) -> byte {
+        c64.SETNAM(strlen(filenameptr), filenameptr)
+        c64.SETLFS(1, drivenumber, 0)
+        uword end_address = address + size
+
+        %asm {{
+            lda  address
+            sta  P8ZP_SCRATCH_W1
+            lda  address+1
+            sta  P8ZP_SCRATCH_W1+1
+            stx  P8ZP_SCRATCH_REG
+            lda  #<P8ZP_SCRATCH_W1
+            ldx  end_address
+            ldy  end_address+1
+            jsr  c64.SAVE
+            php
+            ldx  P8ZP_SCRATCH_REG
+            plp
+        }}
+
+        if_cc
+            return c64.READST()==0
+
+        return false
+    }
+
+    sub load(ubyte drivenumber, uword filenameptr, uword address_override) -> uword {
+        c64.SETNAM(strlen(filenameptr), filenameptr)
+        ubyte secondary = 1
+        uword end_of_load = 0
+        if address_override
+            secondary = 0
+        c64.SETLFS(1, drivenumber, secondary)
+        %asm {{
+            stx  P8ZP_SCRATCH_REG
+            lda  #0
+            ldx  address_override
+            ldy  address_override+1
+            jsr  c64.LOAD
+            bcs  +
+            stx  end_of_load
+            sty  end_of_load+1
++           ldx  P8ZP_SCRATCH_REG
+        }}
+
+        if end_of_load
+            return end_of_load - address_override
+
+        return 0
+    }
+
+
+    str filename = "0:??????????????????????????????????????"
+
+    sub delete(ubyte drivenumber, uword filenameptr) {
+        ; -- delete a file on the drive
+        ubyte flen = strlen(filenameptr)
+        filename[0] = 's'
+        filename[1] = ':'
+        memcopy(filenameptr, &filename+2, flen+1)
+        c64.SETNAM(flen+2, filename)
+        c64.SETLFS(1, drivenumber, 15)
+        void c64.OPEN()
+        c64.CLRCHN()
+        c64.CLOSE(1)
+    }
+
+    sub rename(ubyte drivenumber, uword oldfileptr, uword newfileptr) {
+        ; -- rename a file on the drive
+        ubyte flen_old = strlen(oldfileptr)
+        ubyte flen_new = strlen(newfileptr)
+        filename[0] = 'r'
+        filename[1] = ':'
+        memcopy(newfileptr, &filename+2, flen_new)
+        filename[flen_new+2] = '='
+        memcopy(oldfileptr, &filename+3+flen_new, flen_old+1)
+        c64.SETNAM(3+flen_new+flen_old, filename)
+        c64.SETLFS(1, drivenumber, 15)
+        void c64.OPEN()
+        c64.CLRCHN()
+        c64.CLOSE(1)
+    }
+}

compiler/res/prog8lib/math.p8

@@ -4,8 +4,6 @@
 ;
 ; indent format: TABS, size=8
 
-%import c64lib
-
 math {
 	%asminclude "library:math.asm", ""
 }

compiler/res/prog8lib/prog8_lib.p8

@@ -4,8 +4,7 @@
 ;
 ; indent format: TABS, size=8
 
-%import c64lib
-
 prog8_lib {
-	%asminclude "library:prog8lib.asm", ""
+	%asminclude "library:prog8_lib.asm", ""
+	%asminclude "library:prog8_funcs.asm", ""
 }

compiler/res/prog8lib/test_stack.p8

@@ -0,0 +1,48 @@
+%import textio
+
+test_stack {
+
+    asmsub test() {
+        %asm {{
+            stx  _saveX
+            lda  #13
+            jsr  txt.chrout
+            lda  #'-'
+            ldy  #12
+-           jsr  txt.chrout
+            dey
+            bne  -
+            lda  #13
+            jsr  txt.chrout
+            lda  #'x'
+            jsr  txt.chrout
+            lda  #'='
+            jsr  txt.chrout
+            lda  _saveX
+            jsr  txt.print_ub
+            lda  #' '
+            jsr  txt.chrout
+            lda  #'s'
+            jsr  txt.chrout
+            lda  #'p'
+            jsr  txt.chrout
+            lda  #'='
+            jsr  txt.chrout
+            tsx
+            txa
+            jsr  txt.print_ub
+            lda  #13
+            jsr  txt.chrout
+            lda  #'-'
+            ldy  #12
+-           jsr  txt.chrout
+            dey
+            bne  -
+            lda  #13
+            jsr  txt.chrout
+            ldx  _saveX
+            rts
+_saveX   .byte 0
+        }}
+    }
+}

compiler/res/version.txt

@@ -1 +1 @@
-1.70
+5.2

compiler/src/prog8/CompilerMain.kt

@@ -2,14 +2,12 @@ package prog8
 
 import kotlinx.cli.*
 import prog8.ast.base.AstException
-import prog8.compiler.*
+import prog8.compiler.CompilationResult
+import prog8.compiler.compileProgram
+import prog8.compiler.target.C64Target
+import prog8.compiler.target.Cx16Target
 import prog8.compiler.target.CompilationTarget
-import prog8.compiler.target.c64.C64MachineDefinition
-import prog8.compiler.target.c64.Petscii
-import prog8.compiler.target.c64.codegen.AsmGen
 import prog8.parser.ParsingFailedError
-import prog8.vm.astvm.AstVm
-import java.io.IOException
 import java.nio.file.FileSystems
 import java.nio.file.Path
 import java.nio.file.StandardWatchEventKinds
@@ -35,13 +33,14 @@ fun pathFrom(stringPath: String, vararg rest: String): Path  = FileSystems.getDe
 
 private fun compileMain(args: Array<String>) {
     val cli = CommandLineInterface("prog8compiler")
-    val startEmulator by cli.flagArgument("-emu", "auto-start the Vice C-64 emulator after successful compilation")
+    val startEmulator by cli.flagArgument("-emu", "auto-start emulator after successful compilation")
     val outputDir by cli.flagValueArgument("-out", "directory", "directory for output files instead of current directory", ".")
     val dontWriteAssembly by cli.flagArgument("-noasm", "don't create assembly code")
     val dontOptimize by cli.flagArgument("-noopt", "don't perform any optimizations")
-    val launchSimulator by cli.flagArgument("-sim", "launch the builtin execution simulator after compilation")
     val watchMode by cli.flagArgument("-watch", "continuous compilation mode (watches for file changes), greatly increases compilation speed")
-    val compilationTarget by cli.flagValueArgument("-target", "compilertarget", "target output of the compiler, currently only 'c64' (C64 6502 assembly) available", "c64")
+    val slowCodegenWarnings by cli.flagArgument("-slowwarn", "show debug warnings about slow/problematic assembly code generation")
+    val compilationTarget by cli.flagValueArgument("-target", "compilertarget",
+            "target output of the compiler, currently '${C64Target.name}' and '${Cx16Target.name}' available", C64Target.name)
     val moduleFiles by cli.positionalArgumentsList("modules", "main module file(s) to compile", minArgs = 1)
 
     try {
@@ -50,54 +49,48 @@ private fun compileMain(args: Array<String>) {
         exitProcess(1)
     }
 
-    when(compilationTarget) {
-        "c64" -> {
-            with(CompilationTarget) {
-                name = "c64"
-                machine = C64MachineDefinition
-                encodeString = { str -> Petscii.encodePetscii(str, true) }
-                decodeString = { bytes -> Petscii.decodePetscii(bytes, true) }
-                asmGenerator = ::AsmGen
-            }
-        }
-        else -> {
-            System.err.println("invalid compilation target")
-            exitProcess(1)
-        }
-    }
-
     val outputPath = pathFrom(outputDir)
     if(!outputPath.toFile().isDirectory) {
         System.err.println("Output path doesn't exist")
         exitProcess(1)
     }
 
-    if(watchMode && moduleFiles.size<=1) {
+    if(watchMode) {
         val watchservice = FileSystems.getDefault().newWatchService()
 
         while(true) {
-            val filepath = pathFrom(moduleFiles.single()).normalize()
-            println("Continuous watch mode active. Main module: $filepath")
+            println("Continuous watch mode active. Modules: $moduleFiles")
+            val results = mutableListOf<CompilationResult>()
+            for(filepathRaw in moduleFiles) {
+                val filepath = pathFrom(filepathRaw).normalize()
+                val compilationResult = compileProgram(filepath, !dontOptimize, !dontWriteAssembly, slowCodegenWarnings, compilationTarget, outputPath)
+                results.add(compilationResult)
+            }
 
-            try {
-                val compilationResult = compileProgram(filepath, !dontOptimize, !dontWriteAssembly, outputDir=outputPath)
-                println("Imported files (now watching:)")
-                for (importedFile in compilationResult.importedFiles) {
-                    print("  ")
-                    println(importedFile)
-                    importedFile.parent.register(watchservice, StandardWatchEventKinds.ENTRY_MODIFY)
-                }
-                println("[${LocalDateTime.now().withNano(0)}]  Waiting for file changes.")
+            val allImportedFiles = results.flatMap { it.importedFiles }
+            println("Imported files (now watching:)")
+            for (importedFile in allImportedFiles) {
+                print("  ")
+                println(importedFile)
+                val watchDir = importedFile.parent ?: Path.of(".")
+                watchDir.register(watchservice, StandardWatchEventKinds.ENTRY_MODIFY)
+            }
+            println("[${LocalDateTime.now().withNano(0)}]  Waiting for file changes.")
+
+            var recompile=false
+            while(!recompile) {
                 val event = watchservice.take()
-                for(changed in event.pollEvents()) {
+                for (changed in event.pollEvents()) {
                     val changedPath = changed.context() as Path
-                    println("  change detected: $changedPath")
+                    if(allImportedFiles.any { it.fileName == changedPath.fileName }) {
+                        println("  change detected: $changedPath")
+                        recompile = true
+                    }
                 }
                 event.reset()
-                println("\u001b[H\u001b[2J")      // clear the screen
-            } catch (x: Exception) {
-                throw x
             }
+
+            println("\u001b[H\u001b[2J")      // clear the screen
         }
 
     } else {
@@ -105,7 +98,7 @@ private fun compileMain(args: Array<String>) {
             val filepath = pathFrom(filepathRaw).normalize()
             val compilationResult: CompilationResult
             try {
-                compilationResult = compileProgram(filepath, !dontOptimize, !dontWriteAssembly, outputDir=outputPath)
+                compilationResult = compileProgram(filepath, !dontOptimize, !dontWriteAssembly, slowCodegenWarnings, compilationTarget, outputPath)
                 if(!compilationResult.success)
                     exitProcess(1)
             } catch (x: ParsingFailedError) {
@@ -114,36 +107,11 @@ private fun compileMain(args: Array<String>) {
                 exitProcess(1)
             }
 
-            if (launchSimulator) {
-//                val c64 = razorvine.c64emu.C64Machine("C64 emulator launched from Prog8 compiler")
-//                c64.cpu.addBreakpoint(0xea31) { cpu, address ->
-//                    println("zz")
-//                    Cpu6502.BreakpointResultAction()
-//                }
-//                c64.start()
-                println("\nLaunching AST-based simulator...")
-                val vm = AstVm(compilationResult.programAst, compilationTarget)
-                vm.run()
-            }
-
             if (startEmulator) {
                 if (compilationResult.programName.isEmpty())
                     println("\nCan't start emulator because no program was assembled.")
                 else if(startEmulator) {
-                    for(emulator in listOf("x64sc", "x64")) {
-                        println("\nStarting C-64 emulator $emulator...")
-                        val cmdline = listOf(emulator, "-silent", "-moncommands", "${compilationResult.programName}.vice-mon-list",
-                                "-autostartprgmode", "1", "-autostart-warp", "-autostart", compilationResult.programName + ".prg")
-                        val processb = ProcessBuilder(cmdline).inheritIO()
-                        val process: Process
-                        try {
-                            process=processb.start()
-                        } catch(x: IOException) {
-                            continue  // try the next emulator executable
-                        }
-                        process.waitFor()
-                        break
-                    }
+                    CompilationTarget.instance.machine.launchEmulator(compilationResult.programName)
                 }
             }
         }

compiler/src/prog8/ast/AstToSourceCode.kt

@@ -53,12 +53,14 @@ class AstToSourceCode(val output: (text: String) -> Unit, val program: Program):
     }
 
     override fun visit(expr: BinaryExpression) {
+        output("(")
         expr.left.accept(this)
         if(expr.operator.any { it.isLetter() })
             output(" ${expr.operator} ")
         else
             output(expr.operator)
         expr.right.accept(this)
+        output(")")
     }
 
     override fun visit(directive: Directive) {
@@ -85,7 +87,7 @@ class AstToSourceCode(val output: (text: String) -> Unit, val program: Program):
             DataType.ARRAY_W -> "word["
             DataType.ARRAY_F -> "float["
             DataType.STRUCT -> ""       // the name of the struct is enough
-            else -> "?????2"
+            else -> "?????"
         }
     }
 
@@ -102,15 +104,25 @@ class AstToSourceCode(val output: (text: String) -> Unit, val program: Program):
     }
 
     override fun visit(decl: VarDecl) {
+
+        // if the vardecl is a parameter of a subroutine, don't output it again
+        val paramNames = (decl.definingScope() as? Subroutine)?.parameters?.map { it.name }
+        if(paramNames!=null && decl.name in paramNames)
+            return
+
         when(decl.type) {
             VarDeclType.VAR -> {}
             VarDeclType.CONST -> output("const ")
             VarDeclType.MEMORY -> output("&")
         }
-        output(decl.struct?.name ?: "")
+
+        if(decl.datatype==DataType.STRUCT && decl.struct!=null)
+            output(decl.struct!!.name)
+
         output(datatypeString(decl.datatype))
         if(decl.arraysize!=null) {
-            decl.arraysize!!.index.accept(this)
+            decl.arraysize!!.indexNum?.accept(this)
+            decl.arraysize!!.indexVar?.accept(this)
         }
         if(decl.isArray)
             output("]")
@@ -131,10 +143,9 @@ class AstToSourceCode(val output: (text: String) -> Unit, val program: Program):
             for(param in subroutine.parameters.zip(subroutine.asmParameterRegisters)) {
                 val reg =
                         when {
-                            param.second.stack -> "stack"
                             param.second.registerOrPair!=null -> param.second.registerOrPair.toString()
                             param.second.statusflag!=null -> param.second.statusflag.toString()
-                            else -> "?????1"
+                            else -> "?????"
                         }
                 output("${datatypeString(param.first.type)} ${param.first.name} @$reg")
                 if(param.first!==subroutine.parameters.last())
@@ -177,8 +188,6 @@ class AstToSourceCode(val output: (text: String) -> Unit, val program: Program):
 
     private fun outputStatements(statements: List<Statement>) {
         for(stmt in statements) {
-            if(stmt is VarDecl && stmt.autogeneratedDontRemove)
-                continue    // skip autogenerated decls (to avoid generating a newline)
             outputi("")
             stmt.accept(this)
             output("\n")
@@ -283,20 +292,19 @@ class AstToSourceCode(val output: (text: String) -> Unit, val program: Program):
     }
 
     override fun visit(assignment: Assignment) {
-        if(assignment is VariableInitializationAssignment) {
-            val targetVar = assignment.target.identifier?.targetVarDecl(program.namespace)
-            if(targetVar?.struct != null) {
-                // skip STRUCT init assignments
-                return
-            }
-        }
-
-        assignment.target.accept(this)
-        if (assignment.aug_op != null)
-            output(" ${assignment.aug_op} ")
-        else
+        val binExpr = assignment.value as? BinaryExpression
+        if(binExpr!=null && binExpr.left isSameAs assignment.target
+                && binExpr.operator !in setOf("and", "or", "xor")
+                && binExpr.operator !in comparisonOperators) {
+            // we only support the inplace assignments of the form A = A <operator> <value>
+            assignment.target.accept(this)
+            output(" ${binExpr.operator}= ")
+            binExpr.right.accept(this)
+        } else {
+            assignment.target.accept(this)
             output(" = ")
-        assignment.value.accept(this)
+            assignment.value.accept(this)
+        }
     }
 
     override fun visit(postIncrDecr: PostIncrDecr) {
@@ -304,20 +312,13 @@ class AstToSourceCode(val output: (text: String) -> Unit, val program: Program):
         output(postIncrDecr.operator)
     }
 
-    override fun visit(contStmt: Continue) {
-        output("continue")
-    }
-
     override fun visit(breakStmt: Break) {
         output("break")
     }
 
     override fun visit(forLoop: ForLoop) {
         output("for ")
-        if(forLoop.loopRegister!=null)
-            output(forLoop.loopRegister.toString())
-        else
-            forLoop.loopVar!!.accept(this)
+        forLoop.loopVar.accept(this)
         output(" in ")
         forLoop.iterable.accept(this)
         output(" ")
@@ -333,9 +334,16 @@ class AstToSourceCode(val output: (text: String) -> Unit, val program: Program):
 
     override fun visit(repeatLoop: RepeatLoop) {
         output("repeat ")
+        repeatLoop.iterations?.accept(this)
+        output(" ")
         repeatLoop.body.accept(this)
+    }
+
+    override fun visit(untilLoop: UntilLoop) {
+        output("do ")
+        untilLoop.body.accept(this)
         output(" until ")
-        repeatLoop.untilCondition.accept(this)
+        untilLoop.condition.accept(this)
     }
 
     override fun visit(returnStmt: Return) {
@@ -344,19 +352,16 @@ class AstToSourceCode(val output: (text: String) -> Unit, val program: Program):
     }
 
     override fun visit(arrayIndexedExpression: ArrayIndexedExpression) {
-        arrayIndexedExpression.identifier.accept(this)
+        arrayIndexedExpression.arrayvar.accept(this)
         output("[")
-        arrayIndexedExpression.arrayspec.index.accept(this)
+        arrayIndexedExpression.indexer.indexNum?.accept(this)
+        arrayIndexedExpression.indexer.indexVar?.accept(this)
         output("]")
     }
 
     override fun visit(assignTarget: AssignTarget) {
-        if(assignTarget.register!=null)
-            output(assignTarget.register.toString())
-        else {
-            assignTarget.memoryAddress?.accept(this)
-            assignTarget.identifier?.accept(this)
-        }
+        assignTarget.memoryAddress?.accept(this)
+        assignTarget.identifier?.accept(this)
         assignTarget.arrayindexed?.accept(this)
     }
 
@@ -397,10 +402,6 @@ class AstToSourceCode(val output: (text: String) -> Unit, val program: Program):
         outputlni("}}")
     }
 
-    override fun visit(registerExpr: RegisterExpr) {
-        output(registerExpr.register.toString())
-    }
-
     override fun visit(builtinFunctionStatementPlaceholder: BuiltinFunctionStatementPlaceholder) {
         output(builtinFunctionStatementPlaceholder.name)
     }
@@ -434,12 +435,4 @@ class AstToSourceCode(val output: (text: String) -> Unit, val program: Program):
             whenChoice.statements.accept(this)
         outputln("")
     }
-
-    override fun visit(structLv: StructLiteralValue) {
-        outputListMembers(structLv.values.asSequence(), '{', '}')
-    }
-
-    override fun visit(nopStatement: NopStatement) {
-        output("; NOP @ ${nopStatement.position}  $nopStatement")
-    }
 }

compiler/src/prog8/ast/AstToplevel.kt

@@ -3,6 +3,8 @@ package prog8.ast
 import prog8.ast.base.*
 import prog8.ast.expressions.Expression
 import prog8.ast.expressions.IdentifierReference
+import prog8.ast.processing.AstWalker
+import prog8.ast.processing.IAstVisitor
 import prog8.ast.statements.*
 import prog8.functions.BuiltinFunctions
 import java.nio.file.Path
@@ -33,6 +35,20 @@ interface Node {
             return this
         throw FatalAstException("scope missing from $this")
     }
+
+    fun definingBlock(): Block {
+        if(this is Block)
+            return this
+        return findParentNode<Block>(this)!!
+    }
+
+    fun containingStatement(): Statement {
+        if(this is Statement)
+            return this
+        return findParentNode<Statement>(this)!!
+    }
+
+    fun replaceChildNode(node: Node, replacement: Node)
 }
 
 interface IFunctionCall {
@@ -40,6 +56,7 @@ interface IFunctionCall {
     var args: MutableList<Expression>
 }
 
+
 interface INameScope {
     val name: String
     val position: Position
@@ -48,32 +65,31 @@ interface INameScope {
 
     fun linkParents(parent: Node)
 
-    fun subScopes(): Map<String, INameScope> {
-        val subscopes = mutableMapOf<String, INameScope>()
+    fun subScope(name: String): INameScope? {
         for(stmt in statements) {
             when(stmt) {
                 // NOTE: if other nodes are introduced that are a scope, or contain subscopes, they must be added here!
-                is ForLoop -> subscopes[stmt.body.name] = stmt.body
-                is RepeatLoop -> subscopes[stmt.body.name] = stmt.body
-                is WhileLoop -> subscopes[stmt.body.name] = stmt.body
+                is ForLoop -> if(stmt.body.name==name) return stmt.body
+                is UntilLoop -> if(stmt.body.name==name) return stmt.body
+                is WhileLoop -> if(stmt.body.name==name) return stmt.body
                 is BranchStatement -> {
-                    subscopes[stmt.truepart.name] = stmt.truepart
-                    if(stmt.elsepart.containsCodeOrVars())
-                        subscopes[stmt.elsepart.name] = stmt.elsepart
+                    if(stmt.truepart.name==name) return stmt.truepart
+                    if(stmt.elsepart.containsCodeOrVars() && stmt.elsepart.name==name) return stmt.elsepart
                 }
                 is IfStatement -> {
-                    subscopes[stmt.truepart.name] = stmt.truepart
-                    if(stmt.elsepart.containsCodeOrVars())
-                        subscopes[stmt.elsepart.name] = stmt.elsepart
+                    if(stmt.truepart.name==name) return stmt.truepart
+                    if(stmt.elsepart.containsCodeOrVars() && stmt.elsepart.name==name) return stmt.elsepart
                 }
                 is WhenStatement -> {
-                    stmt.choices.forEach { subscopes[it.statements.name] = it.statements }
+                    val scope = stmt.choices.firstOrNull { it.statements.name==name }
+                    if(scope!=null)
+                        return scope.statements
                 }
-                is INameScope -> subscopes[stmt.name] = stmt
+                is INameScope -> if(stmt.name==name) return stmt
                 else -> {}
             }
         }
-        return subscopes
+        return null
     }
 
     fun getLabelOrVariable(name: String): Statement? {
@@ -121,7 +137,7 @@ interface INameScope {
             for(module in localContext.definingModule().program.modules) {
                 var scope: INameScope? = module
                 for(name in scopedName.dropLast(1)) {
-                    scope = scope?.subScopes()?.get(name)
+                    scope = scope?.subScope(name)
                     if(scope==null)
                         break
                 }
@@ -129,19 +145,27 @@ interface INameScope {
                     val result = scope.getLabelOrVariable(scopedName.last())
                     if(result!=null)
                         return result
-                    return scope.subScopes()[scopedName.last()] as Statement?
+                    return scope.subScope(scopedName.last()) as Statement?
                 }
             }
             return null
         } else {
-            // unqualified name, find the scope the localContext is in, look in that first
+            // unqualified name
+            // special case: the do....until statement can also look INSIDE the anonymous scope
+            if(localContext.parent.parent is UntilLoop) {
+                val symbolFromInnerScope = (localContext.parent.parent as UntilLoop).body.getLabelOrVariable(scopedName[0])
+                if(symbolFromInnerScope!=null)
+                    return symbolFromInnerScope
+            }
+
+            // find the scope the localContext is in, look in that first
             var statementScope = localContext
             while(statementScope !is ParentSentinel) {
                 val localScope = statementScope.definingScope()
                 val result = localScope.getLabelOrVariable(scopedName[0])
                 if (result != null)
                     return result
-                val subscope = localScope.subScopes()[scopedName[0]] as Statement?
+                val subscope = localScope.subScope(scopedName[0]) as Statement?
                 if (subscope != null)
                     return subscope
                 // not found in this scope, look one higher up
@@ -158,6 +182,55 @@ interface INameScope {
         if(!statements.remove(stmt))
             throw FatalAstException("stmt to remove wasn't found in scope")
     }
+
+    fun getAllLabels(label: String): List<Label> {
+        val result = mutableListOf<Label>()
+
+        fun find(scope: INameScope) {
+            scope.statements.forEach {
+                when(it) {
+                    is Label -> result.add(it)
+                    is INameScope -> find(it)
+                    is IfStatement -> {
+                        find(it.truepart)
+                        find(it.elsepart)
+                    }
+                    is UntilLoop -> find(it.body)
+                    is RepeatLoop -> find(it.body)
+                    is WhileLoop -> find(it.body)
+                    is WhenStatement -> it.choices.forEach { choice->find(choice.statements) }
+                    else -> { /* do nothing */ }
+                }
+            }
+        }
+
+        find(this)
+        return result
+    }
+
+    fun nextSibling(stmt: Statement): Statement? {
+        val nextIdx = statements.indexOfFirst { it===stmt } + 1
+        return if(nextIdx < statements.size)
+            statements[nextIdx]
+        else
+            null
+    }
+
+    fun previousSibling(stmt: Statement): Statement? {
+        val previousIdx = statements.indexOfFirst { it===stmt } - 1
+        return if(previousIdx>=0)
+            statements[previousIdx]
+        else
+            null
+    }
+
+    fun indexOfChild(stmt: Statement): Int {
+        val idx = statements.indexOfFirst { it===stmt }
+        if(idx>=0)
+            return idx
+        else
+            throw FatalAstException("attempt to find a non-child")
+    }
 }
 
 interface IAssignable {
@@ -167,7 +240,7 @@ interface IAssignable {
 
 /*********** Everything starts from here, the Program; zero or more modules *************/
 
-class Program(val name: String, val modules: MutableList<Module>) {
+class Program(val name: String, val modules: MutableList<Module>): Node {
     val namespace = GlobalNamespace(modules)
 
     val definedLoadAddress: Int
@@ -182,11 +255,29 @@ class Program(val name: String, val modules: MutableList<Module>) {
         return if(mainBlocks.isEmpty()) {
             null
         } else {
-            mainBlocks[0].subScopes()["start"] as Subroutine?
+            mainBlocks[0].subScope("start") as Subroutine?
         }
     }
 
     fun allBlocks(): List<Block> = modules.flatMap { it.statements.filterIsInstance<Block>() }
+
+    override val position: Position = Position.DUMMY
+    override var parent: Node
+        get() = throw FatalAstException("program has no parent")
+        set(_) = throw FatalAstException("can't set parent of program")
+
+    override fun linkParents(parent: Node) {
+        modules.forEach {
+            it.linkParents(namespace)
+        }
+    }
+
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        require(node is Module && replacement is Module)
+        val idx = modules.indexOfFirst { it===node }
+        modules[idx] = replacement
+        replacement.parent = this
+    }
 }
 
 class Module(override val name: String,
@@ -194,12 +285,16 @@ class Module(override val name: String,
              override val position: Position,
              val isLibraryModule: Boolean,
              val source: Path) : Node, INameScope {
+
     override lateinit var parent: Node
     lateinit var program: Program
     val importedBy = mutableListOf<Module>()
     val imports = mutableSetOf<Module>()
 
-    var loadAddress: Int = 0        // can be set with the %address directive
+    val loadAddress: Int by lazy {
+        val address = (statements.singleOrNull { it is Directive && it.directive == "%address" } as? Directive)?.args?.single()?.int ?: 0
+        address
+    }
 
     override fun linkParents(parent: Node) {
         this.parent = parent
@@ -207,20 +302,34 @@ class Module(override val name: String,
     }
 
     override fun definingScope(): INameScope = program.namespace
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        require(node is Statement && replacement is Statement)
+        val idx = statements.indexOfFirst { it===node }
+        statements[idx] = replacement
+        replacement.parent = this
+    }
 
     override fun toString() = "Module(name=$name, pos=$position, lib=$isLibraryModule)"
+
+    fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    fun accept(visitor: AstWalker, parent: Node) = visitor.visit(this, parent)
 }
 
+
 class GlobalNamespace(val modules: List<Module>): Node, INameScope {
     override val name = "<<<global>>>"
     override val position = Position("<<<global>>>", 0, 0, 0)
-    override val statements = mutableListOf<Statement>()
+    override val statements = mutableListOf<Statement>()        // not used
     override var parent: Node = ParentSentinel
 
     override fun linkParents(parent: Node) {
         modules.forEach { it.linkParents(this) }
     }
 
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        throw FatalAstException("cannot replace anything in the namespace")
+    }
+
     override fun lookup(scopedName: List<String>, localContext: Node): Statement? {
         if (scopedName.size == 1 && scopedName[0] in BuiltinFunctions) {
             // builtin functions always exist, return a dummy localContext for them
@@ -242,11 +351,19 @@ class GlobalNamespace(val modules: List<Module>): Node, INameScope {
                 }
             }
         }
+
+        // special case: the do....until statement can also look INSIDE the anonymous scope
+        if(localContext.parent.parent is UntilLoop) {
+            val symbolFromInnerScope = (localContext.parent.parent as UntilLoop).body.lookup(scopedName, localContext)
+            if(symbolFromInnerScope!=null)
+                return symbolFromInnerScope
+        }
+
         // lookup something from the module.
         return when (val stmt = localContext.definingModule().lookup(scopedName, localContext)) {
-            is Label, is VarDecl, is Block, is Subroutine -> stmt
+            is Label, is VarDecl, is Block, is Subroutine, is StructDecl -> stmt
             null -> null
-            else -> throw NameError("wrong identifier target: $stmt", stmt.position)
+            else -> throw SyntaxError("invalid identifier target type", stmt.position)
         }
     }
 }

compiler/src/prog8/ast/antlr/Antr2Kotlin.kt

@@ -19,18 +19,18 @@ import java.nio.file.Path
 
 private data class NumericLiteral(val number: Number, val datatype: DataType)
 
-
-fun prog8Parser.ModuleContext.toAst(name: String, isLibrary: Boolean, source: Path) : Module {
+internal fun prog8Parser.ModuleContext.toAst(name: String, isLibrary: Boolean, source: Path) : Module {
     val nameWithoutSuffix = if(name.endsWith(".p8")) name.substringBeforeLast('.') else name
-    return Module(nameWithoutSuffix, modulestatement().asSequence().map { it.toAst(isLibrary) }.toMutableList(), toPosition(), isLibrary, source)
+    val directives = this.directive().map { it.toAst() }
+    val blocks = this.block().map { it.toAst(isLibrary) }
+    return Module(nameWithoutSuffix, (directives + blocks).toMutableList(), toPosition(), isLibrary, source)
 }
 
-
 private fun ParserRuleContext.toPosition() : Position {
     val customTokensource = this.start.tokenSource as? CustomLexer
     val filename =
             when {
-                customTokensource!=null -> customTokensource.modulePath.fileName.toString()
+                customTokensource!=null -> customTokensource.modulePath.toString()
                 start.tokenSource.sourceName == IntStream.UNKNOWN_SOURCE_NAME -> "@internal@"
                 else -> File(start.inputStream.sourceName).name
             }
@@ -38,27 +38,23 @@ private fun ParserRuleContext.toPosition() : Position {
     return Position(filename, start.line, start.charPositionInLine, stop.charPositionInLine + stop.text.length)
 }
 
-
-private fun prog8Parser.ModulestatementContext.toAst(isInLibrary: Boolean) : Statement {
-    val directive = directive()?.toAst()
-    if(directive!=null) return directive
-
-    val block = block()?.toAst(isInLibrary)
-    if(block!=null) return block
-
-    throw FatalAstException(text)
+private fun prog8Parser.BlockContext.toAst(isInLibrary: Boolean) : Statement {
+    val blockstatements = block_statement().map {
+        when {
+            it.variabledeclaration()!=null -> it.variabledeclaration().toAst()
+            it.subroutinedeclaration()!=null -> it.subroutinedeclaration().toAst()
+            it.directive()!=null -> it.directive().toAst()
+            it.inlineasm()!=null -> it.inlineasm().toAst()
+            else -> throw FatalAstException("weird block statement $it")
+        }
+    }
+    return Block(identifier().text, integerliteral()?.toAst()?.number?.toInt(), blockstatements.toMutableList(), isInLibrary, toPosition())
 }
 
-
-private fun prog8Parser.BlockContext.toAst(isInLibrary: Boolean) : Statement =
-        Block(identifier().text, integerliteral()?.toAst()?.number?.toInt(), statement_block().toAst(), isInLibrary, toPosition())
-
-
 private fun prog8Parser.Statement_blockContext.toAst(): MutableList<Statement> =
         statement().asSequence().map { it.toAst() }.toMutableList()
 
-
-private fun prog8Parser.StatementContext.toAst() : Statement {
+private fun prog8Parser.VariabledeclarationContext.toAst() : Statement {
     vardecl()?.let { return it.toAst() }
 
     varinitializer()?.let {
@@ -66,7 +62,7 @@ private fun prog8Parser.StatementContext.toAst() : Statement {
         return VarDecl(
                 VarDeclType.VAR,
                 vd.datatype()?.toAst() ?: DataType.STRUCT,
-                if(vd.ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE,
+                if (vd.ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE,
                 vd.arrayindex()?.toAst(),
                 vd.varname.text,
                 null,
@@ -114,7 +110,7 @@ private fun prog8Parser.StatementContext.toAst() : Statement {
         return VarDecl(
                 VarDeclType.CONST,
                 vd.datatype()?.toAst() ?: DataType.STRUCT,
-                if(vd.ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE,
+                if (vd.ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE,
                 vd.arrayindex()?.toAst(),
                 vd.varname.text,
                 null,
@@ -131,7 +127,7 @@ private fun prog8Parser.StatementContext.toAst() : Statement {
         return VarDecl(
                 VarDeclType.MEMORY,
                 vd.datatype()?.toAst() ?: DataType.STRUCT,
-                if(vd.ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE,
+                if (vd.ZEROPAGE() != null) ZeropageWish.PREFER_ZEROPAGE else ZeropageWish.DONTCARE,
                 vd.arrayindex()?.toAst(),
                 vd.varname.text,
                 null,
@@ -142,15 +138,38 @@ private fun prog8Parser.StatementContext.toAst() : Statement {
         )
     }
 
+    structdecl()?.let {
+        return StructDecl(it.identifier().text,
+                it.vardecl().map { vd->vd.toAst() }.toMutableList(),
+                toPosition())
+    }
+
+    throw FatalAstException("weird variable decl $this")
+}
+
+private fun prog8Parser.SubroutinedeclarationContext.toAst() : Subroutine {
+    return when {
+        subroutine()!=null -> subroutine().toAst()
+        asmsubroutine()!=null -> asmsubroutine().toAst()
+        romsubroutine()!=null -> romsubroutine().toAst()
+        else -> throw FatalAstException("weird subroutine decl $this")
+    }
+}
+
+private fun prog8Parser.StatementContext.toAst() : Statement {
+    val vardecl = variabledeclaration()?.toAst()
+    if(vardecl!=null) return vardecl
+
     assignment()?.let {
-        return Assignment(it.assign_target().toAst(), null, it.expression().toAst(), it.toPosition())
+        return Assignment(it.assign_target().toAst(), it.expression().toAst(), it.toPosition())
     }
 
     augassignment()?.let {
-        return Assignment(it.assign_target().toAst(),
-                it.operator.text,
-                it.expression().toAst(),
-                it.toPosition())
+        // replace A += X  with  A = A + X
+        val target = it.assign_target().toAst()
+        val oper = it.operator.text.substringBefore('=')
+        val expression = BinaryExpression(target.toExpression(), oper, it.expression().toAst(), it.expression().toPosition())
+        return Assignment(it.assign_target().toAst(), expression, it.toPosition())
     }
 
     postincrdecr()?.let {
@@ -175,8 +194,8 @@ private fun prog8Parser.StatementContext.toAst() : Statement {
     val returnstmt = returnstmt()?.toAst()
     if(returnstmt!=null) return returnstmt
 
-    val sub = subroutine()?.toAst()
-    if(sub!=null) return sub
+    val subroutine = subroutinedeclaration()?.toAst()
+    if(subroutine!=null) return subroutine
 
     val asm = inlineasm()?.toAst()
     if(asm!=null) return asm
@@ -187,82 +206,106 @@ private fun prog8Parser.StatementContext.toAst() : Statement {
     val forloop = forloop()?.toAst()
     if(forloop!=null) return forloop
 
-    val repeatloop = repeatloop()?.toAst()
-    if(repeatloop!=null) return repeatloop
+    val untilloop = untilloop()?.toAst()
+    if(untilloop!=null) return untilloop
 
     val whileloop = whileloop()?.toAst()
     if(whileloop!=null) return whileloop
 
+    val repeatloop = repeatloop()?.toAst()
+    if(repeatloop!=null) return repeatloop
+
     val breakstmt = breakstmt()?.toAst()
     if(breakstmt!=null) return breakstmt
 
-    val continuestmt = continuestmt()?.toAst()
-    if(continuestmt!=null) return continuestmt
-
-    val asmsubstmt = asmsubroutine()?.toAst()
-    if(asmsubstmt!=null) return asmsubstmt
-
     val whenstmt = whenstmt()?.toAst()
     if(whenstmt!=null) return whenstmt
 
-    structdecl()?.let {
-        return StructDecl(it.identifier().text,
-                it.vardecl().map { vd->vd.toAst() }.toMutableList(),
-                toPosition())
-    }
-
     throw FatalAstException("unprocessed source text (are we missing ast conversion rules for parser elements?): $text")
 }
 
-private fun prog8Parser.AsmsubroutineContext.toAst(): Statement {
+private fun prog8Parser.AsmsubroutineContext.toAst(): Subroutine {
+    val subdecl = asmsub_decl().toAst()
+    val statements = statement_block()?.toAst() ?: mutableListOf()
+    return Subroutine(subdecl.name, subdecl.parameters, subdecl.returntypes,
+            subdecl.asmParameterRegisters, subdecl.asmReturnvaluesRegisters,
+            subdecl.asmClobbers, null, true, statements, toPosition())
+}
+
+private fun prog8Parser.RomsubroutineContext.toAst(): Subroutine {
+    val subdecl = asmsub_decl().toAst()
+    val address = integerliteral().toAst().number.toInt()
+    return Subroutine(subdecl.name, subdecl.parameters, subdecl.returntypes,
+            subdecl.asmParameterRegisters, subdecl.asmReturnvaluesRegisters,
+            subdecl.asmClobbers, address, true, mutableListOf(), toPosition())
+}
+
+private class AsmsubDecl(val name: String,
+                         val parameters: List<SubroutineParameter>,
+                         val returntypes: List<DataType>,
+                         val asmParameterRegisters: List<RegisterOrStatusflag>,
+                         val asmReturnvaluesRegisters: List<RegisterOrStatusflag>,
+                         val asmClobbers: Set<CpuRegister>)
+
+private fun prog8Parser.Asmsub_declContext.toAst(): AsmsubDecl {
     val name = identifier().text
-    val address = asmsub_address()?.address?.toAst()?.number?.toInt()
     val params = asmsub_params()?.toAst() ?: emptyList()
     val returns = asmsub_returns()?.toAst() ?: emptyList()
-    val normalParameters = params.map { SubroutineParameter(it.name, it.type, it.position) }
-    val normalReturnvalues = returns.map { it.type }
-    val paramRegisters = params.map { RegisterOrStatusflag(it.registerOrPair, it.statusflag, it.stack) }
-    val returnRegisters = returns.map { RegisterOrStatusflag(it.registerOrPair, it.statusflag, it.stack) }
     val clobbers = asmsub_clobbers()?.clobber()?.toAst() ?: emptySet()
-    val statements = statement_block()?.toAst() ?: mutableListOf()
-    return Subroutine(name, normalParameters, normalReturnvalues,
-            paramRegisters, returnRegisters, clobbers, address, true, statements, toPosition())
+    val normalParameters = params.map { SubroutineParameter(it.name, it.type, it.position) }
+    val normalReturntypes = returns.map { it.type }
+    val paramRegisters = params.map { RegisterOrStatusflag(it.registerOrPair, it.statusflag) }
+    val returnRegisters = returns.map { RegisterOrStatusflag(it.registerOrPair, it.statusflag) }
+    return AsmsubDecl(name, normalParameters, normalReturntypes, paramRegisters, returnRegisters, clobbers)
 }
 
 private class AsmSubroutineParameter(name: String,
                                      type: DataType,
                                      val registerOrPair: RegisterOrPair?,
                                      val statusflag: Statusflag?,
-                                     val stack: Boolean,
                                      position: Position) : SubroutineParameter(name, type, position)
 
 private class AsmSubroutineReturn(val type: DataType,
                                   val registerOrPair: RegisterOrPair?,
                                   val statusflag: Statusflag?,
-                                  val stack: Boolean,
                                   val position: Position)
 
-private fun prog8Parser.ClobberContext.toAst(): Set<Register>
-        = this.register().asSequence().map { it.toAst() }.toSet()
-
-
 private fun prog8Parser.Asmsub_returnsContext.toAst(): List<AsmSubroutineReturn>
-        = asmsub_return().map { AsmSubroutineReturn(it.datatype().toAst(), it.registerorpair()?.toAst(), it.statusregister()?.toAst(), !it.stack?.text.isNullOrEmpty(), toPosition()) }
+        = asmsub_return().map {
+            val register = it.identifier()?.toAst()
+            var registerorpair: RegisterOrPair? = null
+            var statusregister: Statusflag? = null
+            if(register!=null) {
+                when (val name = register.nameInSource.single()) {
+                    in RegisterOrPair.names -> registerorpair = RegisterOrPair.valueOf(name)
+                    in Statusflag.names -> statusregister = Statusflag.valueOf(name)
+                    else -> throw FatalAstException("invalid register or status flag in $it")
+                }
+            }
+            AsmSubroutineReturn(
+                    it.datatype().toAst(),
+                    registerorpair,
+                    statusregister,
+                    toPosition())
+        }
 
 private fun prog8Parser.Asmsub_paramsContext.toAst(): List<AsmSubroutineParameter>
         = asmsub_param().map {
     val vardecl = it.vardecl()
     val datatype = vardecl.datatype()?.toAst() ?: DataType.STRUCT
-    AsmSubroutineParameter(vardecl.varname.text, datatype,
-            it.registerorpair()?.toAst(),
-            it.statusregister()?.toAst(),
-            !it.stack?.text.isNullOrEmpty(), toPosition())
+    val register = it.identifier()?.toAst()
+    var registerorpair: RegisterOrPair? = null
+    var statusregister: Statusflag? = null
+    if(register!=null) {
+        when (val name = register.nameInSource.single()) {
+            in RegisterOrPair.names -> registerorpair = RegisterOrPair.valueOf(name)
+            in Statusflag.names -> statusregister = Statusflag.valueOf(name)
+            else -> throw FatalAstException("invalid register or status flag '$name'")
+        }
+    }
+    AsmSubroutineParameter(vardecl.varname.text, datatype, registerorpair, statusregister, toPosition())
 }
 
-
-private fun prog8Parser.StatusregisterContext.toAst() = Statusflag.valueOf(text)
-
-
 private fun prog8Parser.Functioncall_stmtContext.toAst(): Statement {
     val void = this.VOID() != null
     val location = scoped_identifier().toAst()
@@ -272,7 +315,6 @@ private fun prog8Parser.Functioncall_stmtContext.toAst(): Statement {
         FunctionCallStatement(location, expression_list().toAst().toMutableList(), void, toPosition())
 }
 
-
 private fun prog8Parser.FunctioncallContext.toAst(): FunctionCall {
     val location = scoped_identifier().toAst()
     return if(expression_list() == null)
@@ -281,11 +323,9 @@ private fun prog8Parser.FunctioncallContext.toAst(): FunctionCall {
         FunctionCall(location, expression_list().toAst().toMutableList(), toPosition())
 }
 
-
 private fun prog8Parser.InlineasmContext.toAst() =
         InlineAssembly(INLINEASMBLOCK().text, toPosition())
 
-
 private fun prog8Parser.ReturnstmtContext.toAst() : Return {
     return Return(expression()?.toAst(), toPosition())
 }
@@ -296,20 +336,15 @@ private fun prog8Parser.UnconditionaljumpContext.toAst(): Jump {
     return Jump(address, identifier, null, toPosition())
 }
 
-
 private fun prog8Parser.LabeldefContext.toAst(): Statement =
         Label(children[0].text, toPosition())
 
-
 private fun prog8Parser.SubroutineContext.toAst() : Subroutine {
+    // non-asm subroutine
+    val returntypes = sub_return_part()?.toAst() ?: emptyList()
     return Subroutine(identifier().text,
             sub_params()?.toAst() ?: emptyList(),
-            sub_return_part()?.toAst() ?: emptyList(),
-            emptyList(),
-            emptyList(),
-            emptySet(),
-            null,
-            false,
+            returntypes,
             statement_block()?.toAst() ?: mutableListOf(),
             toPosition())
 }
@@ -319,47 +354,45 @@ private fun prog8Parser.Sub_return_partContext.toAst(): List<DataType> {
     return returns.datatype().map { it.toAst() }
 }
 
-
 private fun prog8Parser.Sub_paramsContext.toAst(): List<SubroutineParameter> =
         vardecl().map {
             val datatype = it.datatype()?.toAst() ?: DataType.STRUCT
             SubroutineParameter(it.varname.text, datatype, it.toPosition())
         }
 
-
 private fun prog8Parser.Assign_targetContext.toAst() : AssignTarget {
-    val register = register()?.toAst()
     val identifier = scoped_identifier()
     return when {
-        register!=null -> AssignTarget(register, null, null, null, toPosition())
-        identifier!=null -> AssignTarget(null, identifier.toAst(), null, null, toPosition())
-        arrayindexed()!=null -> AssignTarget(null, null, arrayindexed().toAst(), null, toPosition())
-        directmemory()!=null -> AssignTarget(null, null, null, DirectMemoryWrite(directmemory().expression().toAst(), toPosition()), toPosition())
-        else -> AssignTarget(null, scoped_identifier()?.toAst(), null, null, toPosition())
+        identifier!=null -> AssignTarget(identifier.toAst(), null, null, toPosition())
+        arrayindexed()!=null -> AssignTarget(null, arrayindexed().toAst(), null, toPosition())
+        directmemory()!=null -> AssignTarget(null, null, DirectMemoryWrite(directmemory().expression().toAst(), toPosition()), toPosition())
+        else -> AssignTarget(scoped_identifier()?.toAst(), null, null, toPosition())
     }
 }
 
-private fun prog8Parser.RegisterContext.toAst() = Register.valueOf(text.toUpperCase())
+private fun prog8Parser.ClobberContext.toAst() : Set<CpuRegister> {
+    val names = this.identifier().map { it.toAst().nameInSource.single() }
+    return names.map { CpuRegister.valueOf(it) }.toSet()
+}
 
 private fun prog8Parser.DatatypeContext.toAst() = DataType.valueOf(text.toUpperCase())
 
-private fun prog8Parser.RegisterorpairContext.toAst() = RegisterOrPair.valueOf(text.toUpperCase())
-
-
 private fun prog8Parser.ArrayindexContext.toAst() : ArrayIndex =
         ArrayIndex(expression().toAst(), toPosition())
 
-
 private fun prog8Parser.DirectiveContext.toAst() : Directive =
         Directive(directivename.text, directivearg().map { it.toAst() }, toPosition())
 
+private fun prog8Parser.DirectiveargContext.toAst() : DirectiveArg {
+    val str = stringliteral()
+    if(str?.ALT_STRING_ENCODING() != null)
+        throw AstException("${toPosition()} can't use alternate string encodings for directive arguments")
 
-private fun prog8Parser.DirectiveargContext.toAst() : DirectiveArg =
-        DirectiveArg(stringliteral()?.text, identifier()?.text, integerliteral()?.toAst()?.number?.toInt(), toPosition())
-
+    return DirectiveArg(stringliteral()?.text, identifier()?.text, integerliteral()?.toAst()?.number?.toInt(), toPosition())
+}
 
 private fun prog8Parser.IntegerliteralContext.toAst(): NumericLiteral {
-    fun makeLiteral(text: String, radix: Int, forceWord: Boolean): NumericLiteral {
+    fun makeLiteral(text: String, radix: Int): NumericLiteral {
         val integer: Int
         var datatype = DataType.UBYTE
         when (radix) {
@@ -397,19 +430,18 @@ private fun prog8Parser.IntegerliteralContext.toAst(): NumericLiteral {
             }
             else -> throw FatalAstException("invalid radix")
         }
-        return NumericLiteral(integer, if (forceWord) DataType.UWORD else datatype)
+        return NumericLiteral(integer, datatype)
     }
     val terminal: TerminalNode = children[0] as TerminalNode
     val integerPart = this.intpart.text
     return when (terminal.symbol.type) {
-        prog8Parser.DEC_INTEGER -> makeLiteral(integerPart, 10, wordsuffix()!=null)
-        prog8Parser.HEX_INTEGER -> makeLiteral(integerPart.substring(1), 16, wordsuffix()!=null)
-        prog8Parser.BIN_INTEGER -> makeLiteral(integerPart.substring(1), 2, wordsuffix()!=null)
+        prog8Parser.DEC_INTEGER -> makeLiteral(integerPart, 10)
+        prog8Parser.HEX_INTEGER -> makeLiteral(integerPart.substring(1), 16)
+        prog8Parser.BIN_INTEGER -> makeLiteral(integerPart.substring(1), 2)
         else -> throw FatalAstException(terminal.text)
     }
 }
 
-
 private fun prog8Parser.ExpressionContext.toAst() : Expression {
 
     val litval = literalvalue()
@@ -430,11 +462,12 @@ private fun prog8Parser.ExpressionContext.toAst() : Expression {
                     else -> throw FatalAstException("invalid datatype for numeric literal")
                 }
                 litval.floatliteral()!=null -> NumericLiteralValue(DataType.FLOAT, litval.floatliteral().toAst(), litval.toPosition())
-                litval.stringliteral()!=null -> StringLiteralValue(unescape(litval.stringliteral().text, litval.toPosition()), litval.toPosition())
+                litval.stringliteral()!=null -> litval.stringliteral().toAst()
                 litval.charliteral()!=null -> {
                     try {
-                        NumericLiteralValue(DataType.UBYTE, CompilationTarget.encodeString(
-                                unescape(litval.charliteral().text, litval.toPosition()))[0], litval.toPosition())
+                        NumericLiteralValue(DataType.UBYTE, CompilationTarget.instance.encodeString(
+                                unescape(litval.charliteral().SINGLECHAR().text, litval.toPosition()),
+                                litval.charliteral().ALT_STRING_ENCODING()!=null)[0], litval.toPosition())
                     } catch (ce: CharConversionException) {
                         throw SyntaxError(ce.message ?: ce.toString(), litval.toPosition())
                     }
@@ -443,20 +476,13 @@ private fun prog8Parser.ExpressionContext.toAst() : Expression {
                     val array = litval.arrayliteral().toAst()
                     // the actual type of the arraysize can not yet be determined here (missing namespace & heap)
                     // the ConstantFold takes care of that and converts the type if needed.
-                    ArrayLiteralValue(DataType.ARRAY_UB, array, position = litval.toPosition())
-                }
-                litval.structliteral()!=null -> {
-                    val values = litval.structliteral().expression().map { it.toAst() }
-                    StructLiteralValue(values, litval.toPosition())
+                    ArrayLiteralValue(InferredTypes.InferredType.unknown(), array, position = litval.toPosition())
                 }
                 else -> throw FatalAstException("invalid parsed literal")
             }
         }
     }
 
-    if(register()!=null)
-        return RegisterExpr(register().toAst(), register().toPosition())
-
     if(scoped_identifier()!=null)
         return scoped_identifier().toAst()
 
@@ -470,7 +496,8 @@ private fun prog8Parser.ExpressionContext.toAst() : Expression {
     if(funcall!=null) return funcall
 
     if (rangefrom!=null && rangeto!=null) {
-        val step = rangestep?.toAst() ?: NumericLiteralValue(DataType.UBYTE, 1, toPosition())
+        val defaultstep = if(rto.text == "to") 1 else -1
+        val step = rangestep?.toAst() ?: NumericLiteralValue(DataType.UBYTE, defaultstep, toPosition())
         return RangeExpr(rangefrom.toAst(), rangeto.toAst(), step, toPosition())
     }
 
@@ -492,6 +519,8 @@ private fun prog8Parser.ExpressionContext.toAst() : Expression {
     throw FatalAstException(text)
 }
 
+private fun prog8Parser.StringliteralContext.toAst(): StringLiteralValue =
+    StringLiteralValue(unescape(this.STRING().text, toPosition()), ALT_STRING_ENCODING()!=null, toPosition())
 
 private fun prog8Parser.ArrayindexedContext.toAst(): ArrayIndexedExpression {
     return ArrayIndexedExpression(scoped_identifier().toAst(),
@@ -499,28 +528,22 @@ private fun prog8Parser.ArrayindexedContext.toAst(): ArrayIndexedExpression {
             toPosition())
 }
 
-
 private fun prog8Parser.Expression_listContext.toAst() = expression().map{ it.toAst() }
 
-
 private fun prog8Parser.IdentifierContext.toAst() : IdentifierReference =
         IdentifierReference(listOf(text), toPosition())
 
-
 private fun prog8Parser.Scoped_identifierContext.toAst() : IdentifierReference =
         IdentifierReference(NAME().map { it.text }, toPosition())
 
-
 private fun prog8Parser.FloatliteralContext.toAst() = text.toDouble()
 
-
 private fun prog8Parser.BooleanliteralContext.toAst() = when(text) {
     "true" -> true
     "false" -> false
     else -> throw FatalAstException(text)
 }
 
-
 private fun prog8Parser.ArrayliteralContext.toAst() : Array<Expression> =
         expression().map { it.toAst() }.toTypedArray()
 
@@ -538,7 +561,6 @@ private fun prog8Parser.Else_partContext.toAst(): MutableList<Statement> {
     return statement_block()?.toAst() ?: mutableListOf(statement().toAst())
 }
 
-
 private fun prog8Parser.Branch_stmtContext.toAst(): BranchStatement {
     val branchcondition = branchcondition().toAst()
     val trueStatements = statement_block()?.toAst() ?: mutableListOf(statement().toAst())
@@ -551,25 +573,19 @@ private fun prog8Parser.Branch_stmtContext.toAst(): BranchStatement {
 
 private fun prog8Parser.BranchconditionContext.toAst() = BranchCondition.valueOf(text.substringAfter('_').toUpperCase())
 
-
 private fun prog8Parser.ForloopContext.toAst(): ForLoop {
-    val loopregister = register()?.toAst()
-    val loopvar = identifier()?.toAst()
+    val loopvar = identifier().toAst()
     val iterable = expression()!!.toAst()
     val scope =
             if(statement()!=null)
                 AnonymousScope(mutableListOf(statement().toAst()), statement().toPosition())
             else
                 AnonymousScope(statement_block().toAst(), statement_block().toPosition())
-    return ForLoop(loopregister, loopvar, iterable, scope, toPosition())
+    return ForLoop(loopvar, iterable, scope, toPosition())
 }
 
-
-private fun prog8Parser.ContinuestmtContext.toAst() = Continue(toPosition())
-
 private fun prog8Parser.BreakstmtContext.toAst() = Break(toPosition())
 
-
 private fun prog8Parser.WhileloopContext.toAst(): WhileLoop {
     val condition = expression().toAst()
     val statements = statement_block()?.toAst() ?: mutableListOf(statement().toAst())
@@ -578,13 +594,20 @@ private fun prog8Parser.WhileloopContext.toAst(): WhileLoop {
     return WhileLoop(condition, scope, toPosition())
 }
 
-
 private fun prog8Parser.RepeatloopContext.toAst(): RepeatLoop {
+    val iterations = expression()?.toAst()
+    val statements = statement_block()?.toAst() ?: mutableListOf(statement().toAst())
+    val scope = AnonymousScope(statements, statement_block()?.toPosition()
+            ?: statement().toPosition())
+    return RepeatLoop(iterations, scope, toPosition())
+}
+
+private fun prog8Parser.UntilloopContext.toAst(): UntilLoop {
     val untilCondition = expression().toAst()
     val statements = statement_block()?.toAst() ?: mutableListOf(statement().toAst())
     val scope = AnonymousScope(statements, statement_block()?.toPosition()
             ?: statement().toPosition())
-    return RepeatLoop(scope, untilCondition, toPosition())
+    return UntilLoop(scope, untilCondition, toPosition())
 }
 
 private fun prog8Parser.WhenstmtContext.toAst(): WhenStatement {
@@ -618,7 +641,20 @@ private fun prog8Parser.VardeclContext.toAst(): VarDecl {
     )
 }
 
-internal fun escape(str: String) = str.replace("\t", "\\t").replace("\n", "\\n").replace("\r", "\\r")
+internal fun escape(str: String): String {
+    val es = str.map {
+        when(it) {
+            '\t' -> "\\t"
+            '\n' -> "\\n"
+            '\r' -> "\\r"
+            '"' -> "\\\""
+            in '\u8000'..'\u80ff' -> "\\x" + (it.toInt() - 0x8000).toString(16).padStart(2, '0')
+            in '\u0000'..'\u00ff' -> it.toString()
+            else -> "\\u" + it.toInt().toString(16).padStart(4, '0')
+        }
+    }
+    return es.joinToString("")
+}
 
 internal fun unescape(str: String, position: Position): String {
     val result = mutableListOf<Char>()
@@ -632,9 +668,15 @@ internal fun unescape(str: String, position: Position): String {
                 'n' -> '\n'
                 'r' -> '\r'
                 '"' -> '"'
+                '\'' -> '\''
                 'u' -> {
                     "${iter.nextChar()}${iter.nextChar()}${iter.nextChar()}${iter.nextChar()}".toInt(16).toChar()
                 }
+                'x' -> {
+                    // special hack 0x8000..0x80ff  will be outputted verbatim without encoding
+                    val hex = ("" + iter.nextChar() + iter.nextChar()).toInt(16)
+                    (0x8000 + hex).toChar()
+                }
                 else -> throw SyntaxError("invalid escape char in string: \\$ec", position)
             })
         } else {
@@ -643,4 +685,3 @@ internal fun unescape(str: String, position: Position): String {
     }
     return result.joinToString("")
 }
-

compiler/src/prog8/ast/base/Base.kt

@@ -21,35 +21,39 @@ enum class DataType {
     STRUCT;             // pass by reference
 
     /**
-     * is the type assignable to the given other type?
+     * is the type assignable to the given other type (perhaps via a typecast) without loss of precision?
      */
     infix fun isAssignableTo(targetType: DataType) =
-            // what types are assignable to others without loss of precision?
             when(this) {
                 UBYTE -> targetType in setOf(UBYTE, WORD, UWORD, FLOAT)
                 BYTE -> targetType in setOf(BYTE, WORD, FLOAT)
                 UWORD -> targetType in setOf(UWORD, FLOAT)
                 WORD -> targetType in setOf(WORD, FLOAT)
                 FLOAT -> targetType == FLOAT
-                STR -> targetType == STR
-                in ArrayDatatypes -> targetType == this
+                STR -> targetType == STR || targetType == UWORD
+                in ArrayDatatypes -> targetType == this || targetType == UWORD
                 else -> false
             }
 
-
     infix fun isAssignableTo(targetTypes: Set<DataType>) = targetTypes.any { this isAssignableTo it }
+    infix fun isNotAssignableTo(targetType: DataType) = !this.isAssignableTo(targetType)
+    infix fun isNotAssignableTo(targetTypes: Set<DataType>) = !this.isAssignableTo(targetTypes)
 
     infix fun largerThan(other: DataType) =
-            when(this) {
-                in ByteDatatypes -> false
-                in WordDatatypes -> other in ByteDatatypes
+            when {
+                this == other -> false
+                this in ByteDatatypes -> false
+                this in WordDatatypes -> other in ByteDatatypes
+                this==STR && other==UWORD || this==UWORD && other==STR -> false
                 else -> true
             }
 
     infix fun equalsSize(other: DataType) =
-            when(this) {
-                in ByteDatatypes -> other in ByteDatatypes
-                in WordDatatypes -> other in WordDatatypes
+            when {
+                this == other -> true
+                this in ByteDatatypes -> other in ByteDatatypes
+                this in WordDatatypes -> other in WordDatatypes
+                this==STR && other==UWORD || this==UWORD && other==STR -> true
                 else -> false
             }
 
@@ -57,14 +61,14 @@ enum class DataType {
         return when(this) {
             in ByteDatatypes -> 1
             in WordDatatypes -> 2
-            FLOAT -> CompilationTarget.machine.FLOAT_MEM_SIZE
-            in PassByReferenceDatatypes -> 2
+            FLOAT -> CompilationTarget.instance.machine.FLOAT_MEM_SIZE
+            in PassByReferenceDatatypes -> CompilationTarget.instance.machine.POINTER_MEM_SIZE
             else -> -9999999
         }
     }
 }
 
-enum class Register {
+enum class CpuRegister {
     A,
     X,
     Y
@@ -76,14 +80,25 @@ enum class RegisterOrPair {
     Y,
     AX,
     AY,
-    XY
+    XY,
+    FAC1,
+    FAC2;
+
+    companion object {
+        val names by lazy { values().map { it.toString()} }
+    }
+
 }       // only used in parameter and return value specs in asm subroutines
 
 enum class Statusflag {
     Pc,
     Pz,
     Pv,
-    Pn
+    Pn;
+
+    companion object {
+        val names by lazy { values().map { it.toString()} }
+    }
 }
 
 enum class BranchCondition {
@@ -126,6 +141,13 @@ val ArrayElementTypes = mapOf(
         DataType.ARRAY_W to DataType.WORD,
         DataType.ARRAY_UW to DataType.UWORD,
         DataType.ARRAY_F to DataType.FLOAT)
+val ElementArrayTypes = 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
+)
 
 // find the parent node of a specific type or interface
 // (useful to figure out in what namespace/block something is defined, etc)
@@ -143,8 +165,16 @@ object ParentSentinel : Node {
     override val position = Position("<<sentinel>>", 0, 0, 0)
     override var parent: Node = this
     override fun linkParents(parent: Node) {}
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        replacement.parent = this
+    }
 }
 
 data class Position(val file: String, val line: Int, val startCol: Int, val endCol: Int) {
     override fun toString(): String = "[$file: line $line col ${startCol+1}-${endCol+1}]"
+    fun toClickableStr(): String = "$file:$line:$startCol:"
+
+    companion object {
+        val DUMMY = Position("<dummy>", 0, 0, 0)
+    }
 }

compiler/src/prog8/ast/base/ErrorReporting.kt

@@ -3,35 +3,42 @@ package prog8.ast.base
 import prog8.parser.ParsingFailedError
 
 
-fun printErrors(errors: List<Any>, moduleName: String) {
-    val reportedMessages = mutableSetOf<String>()
-    System.err.print("\u001b[91m")  // bright red
-    errors.forEach {
-        val msg = it.toString()
-        if(msg !in reportedMessages) {
-            System.err.println(msg)
-            reportedMessages.add(msg)
-        }
+class ErrorReporter {
+    private enum class MessageSeverity {
+        WARNING,
+        ERROR
     }
-    System.err.print("\u001b[0m")  // reset color
-    if(reportedMessages.isNotEmpty())
-        throw ParsingFailedError("There are ${reportedMessages.size} errors in module '$moduleName'.")
-}
-
-
-fun printWarning(msg: String, position: Position, detailInfo: String?=null) {
-    print("\u001b[93m")  // bright yellow
-    print("$position Warning: $msg")
-    if(detailInfo==null)
-        print("\n")
-    else
-        println(": $detailInfo\n")
-    print("\u001b[0m")  // normal
-}
-
-
-fun printWarning(msg: String) {
-    print("\u001b[93m")  // bright yellow
-    print("Warning: $msg")
-    print("\u001b[0m\n")  // normal
+    private class CompilerMessage(val severity: MessageSeverity, val message: String, val position: Position)
+
+    private val messages = mutableListOf<CompilerMessage>()
+    private val alreadyReportedMessages = mutableSetOf<String>()
+
+    fun err(msg: String, position: Position) = messages.add(CompilerMessage(MessageSeverity.ERROR, msg, position))
+    fun warn(msg: String, position: Position) = messages.add(CompilerMessage(MessageSeverity.WARNING, msg, position))
+
+    fun handle() {
+        var numErrors = 0
+        var numWarnings = 0
+        messages.forEach {
+            when(it.severity) {
+                MessageSeverity.ERROR -> System.err.print("\u001b[91m")  // bright red
+                MessageSeverity.WARNING -> System.err.print("\u001b[93m")  // bright yellow
+            }
+            val msg = "${it.position.toClickableStr()} ${it.severity} ${it.message}".trim()
+            if(msg !in alreadyReportedMessages) {
+                System.err.println(msg)
+                alreadyReportedMessages.add(msg)
+                when(it.severity) {
+                    MessageSeverity.WARNING -> numWarnings++
+                    MessageSeverity.ERROR -> numErrors++
+                }
+            }
+            System.err.print("\u001b[0m")  // reset color
+        }
+        messages.clear()
+        if(numErrors>0)
+            throw ParsingFailedError("There are $numErrors errors and $numWarnings warnings.")
+    }
+
+    fun isEmpty() = messages.isEmpty()
 }

compiler/src/prog8/ast/base/Errors.kt

@@ -2,21 +2,17 @@ package prog8.ast.base
 
 import prog8.ast.expressions.IdentifierReference
 
-class FatalAstException (override var message: String) : Exception(message)
+open class FatalAstException (override var message: String) : Exception(message)
 
 open class AstException (override var message: String) : Exception(message)
 
-class SyntaxError(override var message: String, val position: Position) : AstException(message) {
-    override fun toString() = "$position Syntax error: $message"
-}
-
-open class NameError(override var message: String, val position: Position) : AstException(message) {
-    override fun toString() = "$position Name error: $message"
+open class SyntaxError(override var message: String, val position: Position) : AstException(message) {
+    override fun toString() = "${position.toClickableStr()} Syntax error: $message"
 }
 
 class ExpressionError(message: String, val position: Position) : AstException(message) {
-    override fun toString() = "$position Error: $message"
+    override fun toString() = "${position.toClickableStr()} Error: $message"
 }
 
 class UndefinedSymbolError(symbol: IdentifierReference)
-    : NameError("undefined symbol: ${symbol.nameInSource.joinToString(".")}", symbol.position)
+    : SyntaxError("undefined symbol: ${symbol.nameInSource.joinToString(".")}", symbol.position)

compiler/src/prog8/ast/base/Extensions.kt

@@ -3,67 +3,100 @@ package prog8.ast.base
 import prog8.ast.Module
 import prog8.ast.Program
 import prog8.ast.processing.*
+import prog8.ast.statements.Directive
 import prog8.compiler.CompilationOptions
-import prog8.optimizer.FlattenAnonymousScopesAndRemoveNops
+import prog8.compiler.BeforeAsmGenerationAstChanger
 
 
-// the name of the subroutine that should be called for every block to initialize its variables
-internal const val initvarsSubName="prog8_init_vars"
-
-
-internal fun Program.removeNopsFlattenAnonScopes() {
-    val flattener = FlattenAnonymousScopesAndRemoveNops()
-    flattener.visit(this)
-}
-
-
-internal fun Program.checkValid(compilerOptions: CompilationOptions) {
-    val checker = AstChecker(this, compilerOptions)
-    checker.visit(this)
-    printErrors(checker.result(), name)
-}
-
-
-internal fun Program.anonscopeVarsCleanup() {
-    val mover = AnonymousScopeVarsCleanup(this)
-    mover.visit(this)
-    printErrors(mover.result(), name)
-}
-
-
-internal fun Program.reorderStatements() {
-    val initvalueCreator = VarInitValueAndAddressOfCreator(this)
-    initvalueCreator.visit(this)
-
-    val checker = StatementReorderer(this)
+internal fun Program.checkValid(compilerOptions: CompilationOptions, errors: ErrorReporter) {
+    val checker = AstChecker(this, compilerOptions, errors)
     checker.visit(this)
 }
 
-internal fun Program.addTypecasts() {
-    val caster = TypecastsAdder(this)
+internal fun Program.processAstBeforeAsmGeneration(errors: ErrorReporter) {
+    val fixer = BeforeAsmGenerationAstChanger(this, errors)
+    fixer.visit(this)
+    fixer.applyModifications()
+}
+
+internal fun Program.reorderStatements(errors: ErrorReporter) {
+    val reorder = StatementReorderer(this, errors)
+    reorder.visit(this)
+    reorder.applyModifications()
+}
+
+internal fun Program.addTypecasts(errors: ErrorReporter) {
+    val caster = TypecastsAdder(this, errors)
     caster.visit(this)
+    caster.applyModifications()
+}
+
+internal fun Program.verifyFunctionArgTypes() {
+    val fixer = VerifyFunctionArgTypes(this)
+    fixer.visit(this)
 }
 
 internal fun Module.checkImportedValid() {
-    val checker = ImportedModuleDirectiveRemover()
-    checker.visit(this)
-    printErrors(checker.result(), name)
+    val imr = ImportedModuleDirectiveRemover()
+    imr.visit(this, this.parent)
+    imr.applyModifications()
 }
 
-internal fun Program.checkRecursion() {
-    val checker = AstRecursionChecker(namespace)
-    checker.visit(this)
-    printErrors(checker.result(), name)
-}
+internal fun Program.checkIdentifiers(errors: ErrorReporter) {
 
+    val checker2 = AstIdentifiersChecker(this, errors)
+    checker2.visit(this)
 
-internal fun Program.checkIdentifiers() {
-    val checker = AstIdentifiersChecker(this)
-    checker.visit(this)
-
-    if(modules.map {it.name}.toSet().size != modules.size) {
-        throw FatalAstException("modules should all be unique")
+    if(errors.isEmpty()) {
+        val transforms = AstVariousTransforms(this)
+        transforms.visit(this)
+        transforms.applyModifications()
+        val lit2decl = LiteralsToAutoVars(this)
+        lit2decl.visit(this)
+        lit2decl.applyModifications()
     }
 
-    printErrors(checker.result(), name)
+    if (modules.map { it.name }.toSet().size != modules.size) {
+        throw FatalAstException("modules should all be unique")
+    }
+}
+
+internal fun Program.variousCleanups() {
+    val process = VariousCleanups()
+    process.visit(this)
+    process.applyModifications()
+}
+
+internal fun Program.moveMainAndStartToFirst() {
+    // the module containing the program entrypoint is moved to the first in the sequence.
+    // the "main" block containing the entrypoint is moved to the top in there,
+    // and finally the entrypoint subroutine "start" itself is moved to the top in that block.
+
+    val directives = modules[0].statements.filterIsInstance<Directive>()
+    val start = this.entrypoint()
+    if(start!=null) {
+        val mod = start.definingModule()
+        val block = start.definingBlock()
+        if(!modules.remove(mod))
+            throw FatalAstException("module wrong")
+        modules.add(0, mod)
+        mod.remove(block)
+        var afterDirective = mod.statements.indexOfFirst { it !is Directive }
+        if(afterDirective<0)
+            mod.statements.add(block)
+        else
+            mod.statements.add(afterDirective, block)
+        block.remove(start)
+        afterDirective = block.statements.indexOfFirst { it !is Directive }
+        if(afterDirective<0)
+            block.statements.add(start)
+        else
+            block.statements.add(afterDirective, start)
+
+        // overwrite the directives in the module containing the entrypoint
+        for(directive in directives) {
+            modules[0].statements.removeAll { it is Directive && it.directive == directive.directive }
+            modules[0].statements.add(0, directive)
+        }
+    }
 }

compiler/src/prog8/ast/expressions/AstExpressions.kt

@@ -3,49 +3,65 @@ package prog8.ast.expressions
 import prog8.ast.*
 import prog8.ast.antlr.escape
 import prog8.ast.base.*
-import prog8.ast.processing.IAstModifyingVisitor
+import prog8.ast.processing.AstWalker
 import prog8.ast.processing.IAstVisitor
-import prog8.ast.statements.ArrayIndex
-import prog8.ast.statements.BuiltinFunctionStatementPlaceholder
-import prog8.ast.statements.Subroutine
-import prog8.ast.statements.VarDecl
+import prog8.ast.statements.*
 import prog8.compiler.target.CompilationTarget
 import prog8.functions.BuiltinFunctions
+import prog8.functions.CannotEvaluateException
 import prog8.functions.NotConstArgumentException
 import prog8.functions.builtinFunctionReturnType
-import java.util.Objects
+import java.util.*
 import kotlin.math.abs
 
 
 val associativeOperators = setOf("+", "*", "&", "|", "^", "or", "and", "xor", "==", "!=")
-
+val comparisonOperators = setOf("==", "!=", "<", ">", "<=", ">=")
+val augmentAssignmentOperators = setOf("+", "-", "/", "*", "**", "&", "|", "^", "<<", ">>", "%", "and", "or", "xor")
 
 sealed class Expression: Node {
     abstract fun constValue(program: Program): NumericLiteralValue?
-    abstract fun accept(visitor: IAstModifyingVisitor): Expression
     abstract fun accept(visitor: IAstVisitor)
-    abstract fun referencesIdentifiers(vararg name: String): Boolean     // todo: remove this and add identifier usage tracking into CallGraph instead
+    abstract fun accept(visitor: AstWalker, parent: Node)
+    abstract fun referencesIdentifier(vararg scopedName: String): Boolean
     abstract fun inferType(program: Program): InferredTypes.InferredType
 
+    infix fun isSameAs(assigntarget: AssignTarget) = assigntarget.isSameAs(this)
+
     infix fun isSameAs(other: Expression): Boolean {
         if(this===other)
             return true
-        when(this) {
-            is RegisterExpr ->
-                return (other is RegisterExpr && other.register==register)
+        return when(this) {
             is IdentifierReference ->
-                return (other is IdentifierReference && other.nameInSource==nameInSource)
+                (other is IdentifierReference && other.nameInSource==nameInSource)
             is PrefixExpression ->
-                return (other is PrefixExpression && other.operator==operator && other.expression isSameAs expression)
+                (other is PrefixExpression && other.operator==operator && other.expression isSameAs expression)
             is BinaryExpression ->
-                return (other is BinaryExpression && other.operator==operator
+                (other is BinaryExpression && other.operator==operator
                         && other.left isSameAs left
                         && other.right isSameAs right)
             is ArrayIndexedExpression -> {
-                return (other is ArrayIndexedExpression && other.identifier.nameInSource == identifier.nameInSource
-                        && other.arrayspec.index isSameAs arrayspec.index)
+                (other is ArrayIndexedExpression && other.arrayvar.nameInSource == arrayvar.nameInSource
+                        && other.indexer isSameAs indexer)
             }
-            else -> return other==this
+            is DirectMemoryRead -> {
+                (other is DirectMemoryRead && other.addressExpression isSameAs addressExpression)
+            }
+            is TypecastExpression -> {
+                (other is TypecastExpression && other.implicit==implicit && other.type==type && other.expression isSameAs expression)
+            }
+            is AddressOf -> {
+                (other is AddressOf && other.identifier.nameInSource == identifier.nameInSource)
+            }
+            is RangeExpr -> {
+                (other is RangeExpr && other.from==from && other.to==to && other.step==step)
+            }
+            is FunctionCall -> {
+                (other is FunctionCall && other.target.nameInSource == target.nameInSource
+                        && other.args.size == args.size
+                        && other.args.zip(args).all { it.first isSameAs it.second } )
+            }
+            else -> other==this
         }
     }
 }
@@ -59,10 +75,17 @@ class PrefixExpression(val operator: String, var expression: Expression, overrid
         expression.linkParents(this)
     }
 
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        require(node === expression && replacement is Expression)
+        expression = replacement
+        replacement.parent = this
+    }
+
     override fun constValue(program: Program): NumericLiteralValue? = null
-    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
-    override fun referencesIdentifiers(vararg name: String) = expression.referencesIdentifiers(*name)
+    override fun accept(visitor: AstWalker, parent: Node)= visitor.visit(this, parent)
+
+    override fun referencesIdentifier(vararg scopedName: String) = expression.referencesIdentifier(*scopedName)
     override fun inferType(program: Program): InferredTypes.InferredType {
         val inferred = expression.inferType(program)
         return when(operator) {
@@ -99,6 +122,16 @@ class BinaryExpression(var left: Expression, var operator: String, var right: Ex
         right.linkParents(this)
     }
 
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        require(replacement is Expression)
+        when {
+            node===left -> left = replacement
+            node===right -> right = replacement
+            else -> throw FatalAstException("invalid replace, no child $node")
+        }
+        replacement.parent = this
+    }
+
     override fun toString(): String {
         return "[$left $operator $right]"
     }
@@ -106,9 +139,10 @@ class BinaryExpression(var left: Expression, var operator: String, var right: Ex
     // binary expression should actually have been optimized away into a single value, before const value was requested...
     override fun constValue(program: Program): NumericLiteralValue? = null
 
-    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
-    override fun referencesIdentifiers(vararg name: String) = left.referencesIdentifiers(*name) || right.referencesIdentifiers(*name)
+    override fun accept(visitor: AstWalker, parent: Node)= visitor.visit(this, parent)
+
+    override fun referencesIdentifier(vararg scopedName: String) = left.referencesIdentifier(*scopedName) || right.referencesIdentifier(*scopedName)
     override fun inferType(program: Program): InferredTypes.InferredType {
         val leftDt = left.inferType(program)
         val rightDt = right.inferType(program)
@@ -198,23 +232,32 @@ class BinaryExpression(var left: Expression, var operator: String, var right: Ex
     }
 }
 
-class ArrayIndexedExpression(var identifier: IdentifierReference,
-                             val arrayspec: ArrayIndex,
+class ArrayIndexedExpression(var arrayvar: IdentifierReference,
+                             val indexer: ArrayIndex,
                              override val position: Position) : Expression(), IAssignable {
     override lateinit var parent: Node
     override fun linkParents(parent: Node) {
         this.parent = parent
-        identifier.linkParents(this)
-        arrayspec.linkParents(this)
+        arrayvar.linkParents(this)
+        indexer.linkParents(this)
+    }
+
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        when {
+            node===arrayvar -> arrayvar = replacement as IdentifierReference
+            else -> throw FatalAstException("invalid replace")
+        }
+        replacement.parent = this
     }
 
     override fun constValue(program: Program): NumericLiteralValue? = null
-    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
-    override fun referencesIdentifiers(vararg name: String) = identifier.referencesIdentifiers(*name)
+    override fun accept(visitor: AstWalker, parent: Node)= visitor.visit(this, parent)
+
+    override fun referencesIdentifier(vararg scopedName: String) = arrayvar.referencesIdentifier(*scopedName)
 
     override fun inferType(program: Program): InferredTypes.InferredType {
-        val target = identifier.targetStatement(program.namespace)
+        val target = arrayvar.targetStatement(program.namespace)
         if (target is VarDecl) {
             return when (target.datatype) {
                 DataType.STR -> InferredTypes.knownFor(DataType.UBYTE)
@@ -226,7 +269,7 @@ class ArrayIndexedExpression(var identifier: IdentifierReference,
     }
 
     override fun toString(): String {
-        return "ArrayIndexed(ident=$identifier, arraysize=$arrayspec; pos=$position)"
+        return "ArrayIndexed(ident=$arrayvar, arraysize=$indexer; pos=$position)"
     }
 }
 
@@ -238,15 +281,24 @@ class TypecastExpression(var expression: Expression, var type: DataType, val imp
         expression.linkParents(this)
     }
 
-    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        require(replacement is Expression && node===expression)
+        expression = replacement
+        replacement.parent = this
+    }
+
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
-    override fun referencesIdentifiers(vararg name: String) = expression.referencesIdentifiers(*name)
+    override fun accept(visitor: AstWalker, parent: Node)= visitor.visit(this, parent)
+
+    override fun referencesIdentifier(vararg scopedName: String) = expression.referencesIdentifier(*scopedName)
     override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(type)
     override fun constValue(program: Program): NumericLiteralValue? {
         val cv = expression.constValue(program) ?: return null
-        return cv.cast(type)
-        // val value = RuntimeValue(cv.type, cv.asNumericValue!!).cast(type)
-        // return LiteralValue.fromNumber(value.numericValue(), value.type, position).cast(type)
+        val cast = cv.cast(type)
+        return if(cast.isValid)
+            cast.valueOrZero()
+        else
+            null
     }
 
     override fun toString(): String {
@@ -262,11 +314,17 @@ data class AddressOf(var identifier: IdentifierReference, override val position:
         identifier.parent=this
     }
 
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        require(replacement is IdentifierReference && node===identifier)
+        identifier = replacement
+        replacement.parent = this
+    }
+
     override fun constValue(program: Program): NumericLiteralValue? = null
-    override fun referencesIdentifiers(vararg name: String) = false
+    override fun referencesIdentifier(vararg scopedName: String) = false
     override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(DataType.UWORD)
-    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun accept(visitor: AstWalker, parent: Node)= visitor.visit(this, parent)
 }
 
 class DirectMemoryRead(var addressExpression: Expression, override val position: Position) : Expression(), IAssignable {
@@ -277,9 +335,16 @@ class DirectMemoryRead(var addressExpression: Expression, override val position:
         this.addressExpression.linkParents(this)
     }
 
-    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        require(replacement is Expression && node===addressExpression)
+        addressExpression = replacement
+        replacement.parent = this
+    }
+
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
-    override fun referencesIdentifiers(vararg name: String) = false
+    override fun accept(visitor: AstWalker, parent: Node)= visitor.visit(this, parent)
+
+    override fun referencesIdentifier(vararg scopedName: String) = false
     override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(DataType.UBYTE)
     override fun constValue(program: Program): NumericLiteralValue? = null
 
@@ -328,11 +393,15 @@ class NumericLiteralValue(val type: DataType,    // only numerical types allowed
         this.parent = parent
     }
 
-    override fun referencesIdentifiers(vararg name: String) = false
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        throw FatalAstException("can't replace here")
+    }
+
+    override fun referencesIdentifier(vararg scopedName: String) = false
     override fun constValue(program: Program) = this
 
-    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun accept(visitor: AstWalker, parent: Node)= visitor.visit(this, parent)
 
     override fun toString(): String = "NumericLiteral(${type.name}:$number)"
 
@@ -348,88 +417,73 @@ class NumericLiteralValue(val type: DataType,    // only numerical types allowed
 
     operator fun compareTo(other: NumericLiteralValue): Int = number.toDouble().compareTo(other.number.toDouble())
 
-    fun cast(targettype: DataType): NumericLiteralValue {
+    class CastValue(val isValid: Boolean, private val value: NumericLiteralValue?) {
+        fun valueOrZero() = if(isValid) value!! else NumericLiteralValue(DataType.UBYTE, 0, Position.DUMMY)
+    }
+
+    fun cast(targettype: DataType): CastValue {
         if(type==targettype)
-            return this
+            return CastValue(true, this)
         val numval = number.toDouble()
         when(type) {
             DataType.UBYTE -> {
                 if(targettype== DataType.BYTE && numval <= 127)
-                    return NumericLiteralValue(targettype, number.toShort(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toShort(), position))
                 if(targettype== DataType.WORD || targettype== DataType.UWORD)
-                    return NumericLiteralValue(targettype, number.toInt(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toInt(), position))
                 if(targettype== DataType.FLOAT)
-                    return NumericLiteralValue(targettype, number.toDouble(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toDouble(), position))
             }
             DataType.BYTE -> {
                 if(targettype== DataType.UBYTE && numval >= 0)
-                    return NumericLiteralValue(targettype, number.toShort(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toShort(), position))
                 if(targettype== DataType.UWORD && numval >= 0)
-                    return NumericLiteralValue(targettype, number.toInt(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toInt(), position))
                 if(targettype== DataType.WORD)
-                    return NumericLiteralValue(targettype, number.toInt(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toInt(), position))
                 if(targettype== DataType.FLOAT)
-                    return NumericLiteralValue(targettype, number.toDouble(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toDouble(), position))
             }
             DataType.UWORD -> {
                 if(targettype== DataType.BYTE && numval <= 127)
-                    return NumericLiteralValue(targettype, number.toShort(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toShort(), position))
                 if(targettype== DataType.UBYTE && numval <= 255)
-                    return NumericLiteralValue(targettype, number.toShort(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toShort(), position))
                 if(targettype== DataType.WORD && numval <= 32767)
-                    return NumericLiteralValue(targettype, number.toInt(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toInt(), position))
                 if(targettype== DataType.FLOAT)
-                    return NumericLiteralValue(targettype, number.toDouble(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toDouble(), position))
             }
             DataType.WORD -> {
                 if(targettype== DataType.BYTE && numval >= -128 && numval <=127)
-                    return NumericLiteralValue(targettype, number.toShort(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toShort(), position))
                 if(targettype== DataType.UBYTE && numval >= 0 && numval <= 255)
-                    return NumericLiteralValue(targettype, number.toShort(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toShort(), position))
                 if(targettype== DataType.UWORD && numval >=0)
-                    return NumericLiteralValue(targettype, number.toInt(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toInt(), position))
                 if(targettype== DataType.FLOAT)
-                    return NumericLiteralValue(targettype, number.toDouble(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toDouble(), position))
             }
             DataType.FLOAT -> {
                 if (targettype == DataType.BYTE && numval >= -128 && numval <=127)
-                    return NumericLiteralValue(targettype, number.toShort(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toShort(), position))
                 if (targettype == DataType.UBYTE && numval >=0 && numval <= 255)
-                    return NumericLiteralValue(targettype, number.toShort(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toShort(), position))
                 if (targettype == DataType.WORD && numval >= -32768 && numval <= 32767)
-                    return NumericLiteralValue(targettype, number.toInt(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toInt(), position))
                 if (targettype == DataType.UWORD && numval >=0 && numval <= 65535)
-                    return NumericLiteralValue(targettype, number.toInt(), position)
+                    return CastValue(true, NumericLiteralValue(targettype, number.toInt(), position))
             }
             else -> {}
         }
-        throw ExpressionError("can't cast $type into $targettype", position)
-    }
-}
-
-class StructLiteralValue(var values: List<Expression>,
-                         override val position: Position): Expression() {
-    override lateinit var parent: Node
-
-    override fun linkParents(parent: Node) {
-        this.parent=parent
-        values.forEach { it.linkParents(this) }
-    }
-
-    override fun constValue(program: Program): NumericLiteralValue?  = null
-    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
-    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
-    override fun referencesIdentifiers(vararg name: String) = values.any { it.referencesIdentifiers(*name) }
-    override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(DataType.STRUCT)
-
-    override fun toString(): String {
-        return "struct{ ${values.joinToString(", ")} }"
+        return CastValue(false, null)
     }
 }
 
 private var heapIdSequence = 0   // unique ids for strings and arrays "on the heap"
 
 class StringLiteralValue(val value: String,
+                         val altEncoding: Boolean,          // such as: screencodes instead of Petscii for the C64
                          override val position: Position) : Expression() {
     override lateinit var parent: Node
 
@@ -438,22 +492,28 @@ class StringLiteralValue(val value: String,
     override fun linkParents(parent: Node) {
         this.parent = parent
     }
-    override fun referencesIdentifiers(vararg name: String) = false
+
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        throw FatalAstException("can't replace here")
+    }
+
+    override fun referencesIdentifier(vararg scopedName: String) = false
     override fun constValue(program: Program): NumericLiteralValue? = null
-    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun accept(visitor: AstWalker, parent: Node)= visitor.visit(this, parent)
+
     override fun toString(): String = "'${escape(value)}'"
     override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(DataType.STR)
     operator fun compareTo(other: StringLiteralValue): Int = value.compareTo(other.value)
-    override fun hashCode(): Int = value.hashCode()
+    override fun hashCode(): Int = Objects.hash(value, altEncoding)
     override fun equals(other: Any?): Boolean {
         if(other==null || other !is StringLiteralValue)
             return false
-        return value==other.value
+        return value==other.value && altEncoding == other.altEncoding
     }
 }
 
-class ArrayLiteralValue(val type: DataType,     // only array types
+class ArrayLiteralValue(val type: InferredTypes.InferredType,     // inferred because not all array literals hava a known type yet
                         val value: Array<Expression>,
                         override val position: Position) : Expression() {
     override lateinit var parent: Node
@@ -464,12 +524,22 @@ class ArrayLiteralValue(val type: DataType,     // only array types
         this.parent = parent
         value.forEach {it.linkParents(this)}
     }
-    override fun referencesIdentifiers(vararg name: String) = value.any { it.referencesIdentifiers(*name) }
+
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        require(replacement is Expression)
+        val idx = value.indexOfFirst { it===node }
+        value[idx] = replacement
+        replacement.parent = this
+    }
+
+    override fun referencesIdentifier(vararg scopedName: String) = value.any { it.referencesIdentifier(*scopedName) }
     override fun constValue(program: Program): NumericLiteralValue? = null
-    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
+    override fun accept(visitor: AstWalker, parent: Node)= visitor.visit(this, parent)
+
     override fun toString(): String = "$value"
-    override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(type)
+    override fun inferType(program: Program): InferredTypes.InferredType = if(type.isKnown) type else guessDatatype(program)
+
     operator fun compareTo(other: ArrayLiteralValue): Int = throw ExpressionError("cannot order compare arrays", position)
     override fun hashCode(): Int = Objects.hash(value, type)
     override fun equals(other: Any?): Boolean {
@@ -478,8 +548,43 @@ class ArrayLiteralValue(val type: DataType,     // only array types
         return type==other.type && value.contentEquals(other.value)
     }
 
+    fun guessDatatype(program: Program): InferredTypes.InferredType {
+        // Educated guess of the desired array literal's datatype.
+        // If it's inside a for loop, assume the data type of the loop variable is what we want.
+        val forloop = parent as? ForLoop
+        if(forloop != null)  {
+            val loopvarDt = forloop.loopVarDt(program)
+            if(loopvarDt.isKnown) {
+                return if(loopvarDt.typeOrElse(DataType.STRUCT) !in ElementArrayTypes)
+                    InferredTypes.InferredType.unknown()
+                else
+                    InferredTypes.InferredType.known(ElementArrayTypes.getValue(loopvarDt.typeOrElse(DataType.STRUCT)))
+            }
+        }
+
+        // otherwise, select the "biggegst" datatype based on the elements in the array.
+        val datatypesInArray = value.map { it.inferType(program) }
+        require(datatypesInArray.isNotEmpty() && datatypesInArray.all { it.isKnown }) { "can't determine type of empty array" }
+        val dts = datatypesInArray.map { it.typeOrElse(DataType.STRUCT) }
+        return when {
+            DataType.FLOAT in dts -> InferredTypes.InferredType.known(DataType.ARRAY_F)
+            DataType.STR in dts -> InferredTypes.InferredType.known(DataType.ARRAY_UW)
+            DataType.WORD in dts -> InferredTypes.InferredType.known(DataType.ARRAY_W)
+            DataType.UWORD in dts -> InferredTypes.InferredType.known(DataType.ARRAY_UW)
+            DataType.BYTE in dts -> InferredTypes.InferredType.known(DataType.ARRAY_B)
+            DataType.UBYTE in dts -> InferredTypes.InferredType.known(DataType.ARRAY_UB)
+            DataType.ARRAY_UW in dts ||
+                DataType.ARRAY_W in dts ||
+                DataType.ARRAY_UB in dts ||
+                DataType.ARRAY_B in dts ||
+                DataType.ARRAY_F in dts ||
+                DataType.STRUCT in dts -> InferredTypes.InferredType.known(DataType.ARRAY_UW)
+            else -> InferredTypes.InferredType.unknown()
+        }
+    }
+
     fun cast(targettype: DataType): ArrayLiteralValue? {
-        if(type==targettype)
+        if(type.istype(targettype))
             return this
         if(targettype in ArrayDatatypes) {
             val elementType = ArrayElementTypes.getValue(targettype)
@@ -488,17 +593,17 @@ class ArrayLiteralValue(val type: DataType,     // only array types
                 if(num==null) {
                     // an array of UWORDs could possibly also contain AddressOfs, other stuff can't be casted
                     if (elementType != DataType.UWORD || it !is AddressOf)
-                        return null
+                        return null  // can't cast a value of  the array, abort
                     it
                 } else {
-                    try {
-                        num.cast(elementType)
-                    } catch(x: ExpressionError) {
-                        return null
-                    }
+                    val cast = num.cast(elementType)
+                    if(cast.isValid)
+                        cast.valueOrZero()
+                    else
+                        return null // can't cast a value of the array, abort
                 }
             }.toTypedArray()
-            return ArrayLiteralValue(targettype, castArray, position = position)
+            return ArrayLiteralValue(InferredTypes.InferredType.known(targettype), castArray, position = position)
         }
         return null    // invalid type conversion from $this to $targettype
     }
@@ -517,10 +622,22 @@ class RangeExpr(var from: Expression,
         step.linkParents(this)
     }
 
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        require(replacement is Expression)
+        when {
+            from===node -> from=replacement
+            to===node -> to=replacement
+            step===node -> step=replacement
+            else -> throw FatalAstException("invalid replacement")
+        }
+        replacement.parent = this
+    }
+
     override fun constValue(program: Program): NumericLiteralValue? = null
-    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
-    override fun referencesIdentifiers(vararg name: String): Boolean  = from.referencesIdentifiers(*name) || to.referencesIdentifiers(*name)
+    override fun accept(visitor: AstWalker, parent: Node)= visitor.visit(this, parent)
+
+    override fun referencesIdentifier(vararg scopedName: String): Boolean  = from.referencesIdentifier(*scopedName) || to.referencesIdentifier(*scopedName)
     override fun inferType(program: Program): InferredTypes.InferredType {
         val fromDt=from.inferType(program)
         val toDt=to.inferType(program)
@@ -531,7 +648,14 @@ class RangeExpr(var from: Expression,
             fromDt istype DataType.STR && toDt istype DataType.STR -> InferredTypes.knownFor(DataType.STR)
             fromDt istype DataType.WORD || toDt istype DataType.WORD -> InferredTypes.knownFor(DataType.ARRAY_W)
             fromDt istype DataType.BYTE || toDt istype DataType.BYTE -> InferredTypes.knownFor(DataType.ARRAY_B)
-            else -> InferredTypes.knownFor(DataType.ARRAY_UB)
+            else -> {
+                val fdt = fromDt.typeOrElse(DataType.STRUCT)
+                val tdt = toDt.typeOrElse(DataType.STRUCT)
+                if(fdt largerThan tdt)
+                    InferredTypes.knownFor(ElementArrayTypes.getValue(fdt))
+                else
+                    InferredTypes.knownFor(ElementArrayTypes.getValue(tdt))
+            }
         }
     }
     override fun toString(): String {
@@ -552,9 +676,9 @@ class RangeExpr(var from: Expression,
         val fromString = from as? StringLiteralValue
         val toString = to as? StringLiteralValue
         if(fromString!=null && toString!=null ) {
-            // string range -> int range over petscii values
-            fromVal = CompilationTarget.encodeString(fromString.value)[0].toInt()
-            toVal = CompilationTarget.encodeString(toString.value)[0].toInt()
+            // string range -> int range over character values
+            fromVal = CompilationTarget.instance.encodeString(fromString.value, fromString.altEncoding)[0].toInt()
+            toVal = CompilationTarget.instance.encodeString(toString.value, fromString.altEncoding)[0].toInt()
         } else {
             val fromLv = from as? NumericLiteralValue
             val toLv = to as? NumericLiteralValue
@@ -584,24 +708,6 @@ internal fun makeRange(fromVal: Int, toVal: Int, stepVal: Int): IntProgression {
     }
 }
 
-class RegisterExpr(val register: Register, override val position: Position) : Expression(), IAssignable {
-    override lateinit var parent: Node
-
-    override fun linkParents(parent: Node) {
-        this.parent = parent
-    }
-
-    override fun constValue(program: Program): NumericLiteralValue? = null
-    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
-    override fun accept(visitor: IAstVisitor) = visitor.visit(this)
-    override fun referencesIdentifiers(vararg name: String): Boolean = register.name in name
-    override fun toString(): String {
-        return "RegisterExpr(register=$register, pos=$position)"
-    }
-
-    override fun inferType(program: Program): InferredTypes.InferredType = InferredTypes.knownFor(DataType.UBYTE)
-}
-
 data class IdentifierReference(val nameInSource: List<String>, override val position: Position) : Expression(), IAssignable {
     override lateinit var parent: Node
 
@@ -614,10 +720,17 @@ data class IdentifierReference(val nameInSource: List<String>, override val posi
     fun targetVarDecl(namespace: INameScope): VarDecl? = targetStatement(namespace) as? VarDecl
     fun targetSubroutine(namespace: INameScope): Subroutine? = targetStatement(namespace) as? Subroutine
 
+    override fun equals(other: Any?) = other is IdentifierReference && other.nameInSource==nameInSource
+    override fun hashCode() = nameInSource.hashCode()
+
     override fun linkParents(parent: Node) {
         this.parent = parent
     }
 
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        throw FatalAstException("can't replace here")
+    }
+
     override fun constValue(program: Program): NumericLiteralValue? {
         val node = program.namespace.lookup(nameInSource, this)
                 ?: throw UndefinedSymbolError(this)
@@ -634,16 +747,17 @@ data class IdentifierReference(val nameInSource: List<String>, override val posi
         return "IdentifierRef($nameInSource)"
     }
 
-    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
-    override fun referencesIdentifiers(vararg name: String): Boolean = nameInSource.last() in name
+    override fun accept(visitor: AstWalker, parent: Node)= visitor.visit(this, parent)
+
+    override fun referencesIdentifier(vararg scopedName: String): Boolean =
+            nameInSource.size==scopedName.size && nameInSource.toTypedArray().contentEquals(scopedName)
 
     override fun inferType(program: Program): InferredTypes.InferredType {
-        val targetStmt = targetStatement(program.namespace)
-        if(targetStmt is VarDecl) {
-            return InferredTypes.knownFor(targetStmt.datatype)
-        } else {
-            throw FatalAstException("cannot get datatype from identifier reference ${this}, pos=$position")
+        return when (val targetStmt = targetStatement(program.namespace)) {
+            is VarDecl -> InferredTypes.knownFor(targetStmt.datatype)
+            is StructDecl -> InferredTypes.knownFor(DataType.STRUCT)
+            else -> InferredTypes.InferredType.unknown()
         }
     }
 
@@ -659,6 +773,21 @@ data class IdentifierReference(val nameInSource: List<String>, override val posi
             else -> throw FatalAstException("requires a reference value")
         }
     }
+
+    fun firstStructVarName(namespace: INameScope): String? {
+        // take the name of the first struct member of the structvariable instead
+        // if it's just a regular variable, return null.
+        val struct = memberOfStruct(namespace) ?: return null
+        val decl = targetVarDecl(namespace)!!
+        if(decl.datatype!=DataType.STRUCT)
+            return null
+
+        val firstStructMember = struct.nameOfFirstMember()
+        // find the flattened var that belongs to this first struct member
+        val firstVarName = listOf(decl.name, firstStructMember)
+        val firstVar = definingScope().lookup(firstVarName, this) as VarDecl
+        return firstVar.name
+    }
 }
 
 class FunctionCall(override var target: IdentifierReference,
@@ -672,6 +801,16 @@ class FunctionCall(override var target: IdentifierReference,
         args.forEach { it.linkParents(this) }
     }
 
+    override fun replaceChildNode(node: Node, replacement: Node) {
+        if(node===target)
+            target=replacement as IdentifierReference
+        else {
+            val idx = args.indexOfFirst { it===node }
+            args[idx] = replacement as Expression
+        }
+        replacement.parent = this
+    }
+
     override fun constValue(program: Program) = constValue(program, true)
 
     private fun constValue(program: Program, withDatatypeCheck: Boolean): NumericLiteralValue? {
@@ -685,7 +824,7 @@ class FunctionCall(override var target: IdentifierReference,
                 val exprfunc = func.constExpressionFunc
                 if(exprfunc!=null)
                     resultValue = exprfunc(args, position, program)
-                else if(func.returntype==null)
+                else if(func.known_returntype==null)
                     throw ExpressionError("builtin function ${target.nameInSource[0]} can't be used here because it doesn't return a value", position)
             }
 
@@ -702,15 +841,20 @@ class FunctionCall(override var target: IdentifierReference,
             // const-evaluating the builtin function call failed.
             return null
         }
+        catch(x: CannotEvaluateException) {
+            // const-evaluating the builtin function call failed.
+            return null
+        }
     }
 
     override fun toString(): String {
         return "FunctionCall(target=$target, pos=$position)"
     }
 
-    override fun accept(visitor: IAstModifyingVisitor) = visitor.visit(this)
     override fun accept(visitor: IAstVisitor) = visitor.visit(this)
-    override fun referencesIdentifiers(vararg name: String): Boolean = target.referencesIdentifiers(*name) || args.any{it.referencesIdentifiers(*name)}
+    override fun accept(visitor: AstWalker, parent: Node)= visitor.visit(this, parent)
+
+    override fun referencesIdentifier(vararg scopedName: String): Boolean = target.referencesIdentifier(*scopedName) || args.any{it.referencesIdentifier(*scopedName)}
 
     override fun inferType(program: Program): InferredTypes.InferredType {
         val constVal = constValue(program ,false)
@@ -730,6 +874,12 @@ class FunctionCall(override var target: IdentifierReference,
                     return InferredTypes.void()     // no return value
                 if(stmt.returntypes.size==1)
                     return InferredTypes.knownFor(stmt.returntypes[0])
+
+                // multiple return values. Can occur for asmsub routines. If there is exactly one register return value, take that.
+                val numRegisterReturns = stmt.asmReturnvaluesRegisters.count { it.registerOrPair!=null }
+                if(numRegisterReturns==1)
+                    return InferredTypes.InferredType.known(DataType.UBYTE)
+
                 return InferredTypes.unknown()     // has multiple return types... so not a single resulting datatype possible
             }
             else -> return InferredTypes.unknown()

compiler/src/prog8/ast/expressions/InferredTypes.kt

@@ -1,7 +1,7 @@
 package prog8.ast.expressions
 
-import java.util.Objects
 import prog8.ast.base.DataType
+import java.util.*
 
 
 object InferredTypes {
@@ -35,6 +35,13 @@ object InferredTypes {
         }
 
         override fun hashCode(): Int = Objects.hash(isVoid, datatype)
+
+        infix fun isAssignableTo(targetDt: InferredType): Boolean =
+                isKnown && targetDt.isKnown && (datatype!! isAssignableTo targetDt.datatype!!)
+        infix fun isAssignableTo(targetDt: DataType): Boolean =
+                isKnown && (datatype!! isAssignableTo targetDt)
+        infix fun isNotAssignableTo(targetDt: InferredType): Boolean = !this.isAssignableTo(targetDt)
+        infix fun isNotAssignableTo(targetDt: DataType): Boolean = !this.isAssignableTo(targetDt)
     }
 
     private val unknownInstance = InferredType.unknown()

compiler/src/prog8/ast/processing/AnonymousScopeVarsCleanup.kt

@@ -1,47 +0,0 @@
-package prog8.ast.processing
-
-import prog8.ast.Program
-import prog8.ast.base.AstException
-import prog8.ast.base.NameError
-import prog8.ast.statements.AnonymousScope
-import prog8.ast.statements.Statement
-import prog8.ast.statements.VarDecl
-
-class AnonymousScopeVarsCleanup(val program: Program): IAstModifyingVisitor {
-    private val checkResult: MutableList<AstException> = mutableListOf()
-    private val varsToMove: MutableMap<AnonymousScope, List<VarDecl>> = mutableMapOf()
-
-    fun result(): List<AstException> {
-        return checkResult
-    }
-
-    override fun visit(program: Program) {
-        varsToMove.clear()
-        super.visit(program)
-        for((scope, decls) in varsToMove) {
-            val sub = scope.definingSubroutine()!!
-            val existingVariables = sub.statements.filterIsInstance<VarDecl>().associateBy { it.name }
-            var conflicts = false
-            decls.forEach {
-                val existing = existingVariables[it.name]
-                if (existing!=null) {
-                    checkResult.add(NameError("variable ${it.name} already defined in subroutine ${sub.name} at ${existing.position}", it.position))
-                    conflicts = true
-                }
-            }
-            if (!conflicts) {
-                decls.forEach { scope.remove(it) }
-                sub.statements.addAll(0, decls)
-                decls.forEach { it.parent = sub }
-            }
-        }
-    }
-
-    override fun visit(scope: AnonymousScope): Statement {
-        val scope2 = super.visit(scope) as AnonymousScope
-        val vardecls = scope2.statements.filterIsInstance<VarDecl>()
-        varsToMove[scope2] = vardecls
-        return scope2
-    }
-}
-

compiler/src/prog8/ast/processing/AstIdentifiersChecker.kt

@@ -1,8 +1,6 @@
 package prog8.ast.processing
 
-import prog8.ast.INameScope
 import prog8.ast.Module
-import prog8.ast.Node
 import prog8.ast.Program
 import prog8.ast.base.*
 import prog8.ast.expressions.*
@@ -10,104 +8,92 @@ import prog8.ast.statements.*
 import prog8.compiler.target.CompilationTarget
 import prog8.functions.BuiltinFunctions
 
-
-internal class AstIdentifiersChecker(private val program: Program) : IAstModifyingVisitor {
-
-    private val checkResult: MutableList<AstException> = mutableListOf()
-
+internal class AstIdentifiersChecker(private val program: Program, private val errors: ErrorReporter) : IAstVisitor {
     private var blocks = mutableMapOf<String, Block>()
-    private val vardeclsToAdd = mutableMapOf<INameScope, MutableList<VarDecl>>()
-
-    internal fun result(): List<AstException> {
-        return checkResult
-    }
 
     private fun nameError(name: String, position: Position, existing: Statement) {
-        checkResult.add(NameError("name conflict '$name', also defined in ${existing.position.file} line ${existing.position.line}", position))
+        errors.err("name conflict '$name', also defined in ${existing.position.file} line ${existing.position.line}", position)
     }
 
     override fun visit(module: Module) {
-        vardeclsToAdd.clear()
         blocks.clear()  // blocks may be redefined within a different module
+
         super.visit(module)
-        // add any new vardecls to the various scopes
-        for((where, decls) in vardeclsToAdd) {
-            where.statements.addAll(0, decls)
-            decls.forEach { it.linkParents(where as Node) }
-        }
     }
 
-    override fun visit(block: Block): Statement {
+    override fun visit(block: Block) {
+        if(block.name in CompilationTarget.instance.machine.opcodeNames)
+            errors.err("can't use a cpu opcode name as a symbol: '${block.name}'", block.position)
+
         val existing = blocks[block.name]
         if(existing!=null)
             nameError(block.name, block.position, existing)
         else
             blocks[block.name] = block
 
-        return super.visit(block)
+        super.visit(block)
     }
 
-    override fun visit(functionCall: FunctionCall): Expression {
-        if(functionCall.target.nameInSource.size==1 && functionCall.target.nameInSource[0]=="lsb") {
-            // lsb(...) is just an alias for type cast to ubyte, so replace with "... as ubyte"
-            val typecast = TypecastExpression(functionCall.args.single(), DataType.UBYTE, false, functionCall.position)
-            typecast.linkParents(functionCall.parent)
-            return super.visit(typecast)
+    override fun visit(directive: Directive) {
+        if(directive.directive=="%target") {
+            val compatibleTarget = directive.args.single().name
+            if (compatibleTarget != CompilationTarget.instance.name)
+                errors.err("module's compilation target ($compatibleTarget) differs from active target (${CompilationTarget.instance.name})", directive.position)
         }
-        return super.visit(functionCall)
+
+        super.visit(directive)
     }
 
-    override fun visit(decl: VarDecl): Statement {
-        // first, check if there are datatype errors on the vardecl
-        decl.datatypeErrors.forEach { checkResult.add(it) }
+    override fun visit(decl: VarDecl) {
+        decl.datatypeErrors.forEach { errors.err(it.message, it.position) }
 
-        // now check the identifier
         if(decl.name in BuiltinFunctions)
-            // the builtin functions can't be redefined
-            checkResult.add(NameError("builtin function cannot be redefined", decl.position))
+            errors.err("builtin function cannot be redefined", decl.position)
 
-        if(decl.name in CompilationTarget.machine.opcodeNames)
-            checkResult.add(NameError("can't use a cpu opcode name as a symbol: '${decl.name}'", decl.position))
+        if(decl.name in CompilationTarget.instance.machine.opcodeNames)
+            errors.err("can't use a cpu opcode name as a symbol: '${decl.name}'", decl.position)
 
-        // is it a struct variable? then define all its struct members as mangled names,
-        //    and include the original decl as well.
         if(decl.datatype==DataType.STRUCT) {
-            if(decl.structHasBeenFlattened)
+            if (decl.structHasBeenFlattened)
                 return super.visit(decl)    // don't do this multiple times
 
-            if(decl.struct==null) {
-                checkResult.add(NameError("undefined struct type", decl.position))
+            if (decl.struct == null) {
+                errors.err("undefined struct type", decl.position)
                 return super.visit(decl)
             }
 
-            if(decl.struct!!.statements.any { (it as VarDecl).datatype !in NumericDatatypes})
+            if (decl.struct!!.statements.any { (it as VarDecl).datatype !in NumericDatatypes })
                 return super.visit(decl)     // a non-numeric member, not supported. proper error is given by AstChecker later
 
-            if(decl.value is NumericLiteralValue) {
-                checkResult.add(ExpressionError("you cannot initialize a struct using a single value", decl.position))
+            if (decl.value is NumericLiteralValue) {
+                errors.err("you cannot initialize a struct using a single value", decl.position)
                 return super.visit(decl)
             }
 
-            val decls = decl.flattenStructMembers()
-            decls.add(decl)
-            val result = AnonymousScope(decls, decl.position)
-            result.linkParents(decl.parent)
-            return result
+            if (decl.value != null && decl.value !is ArrayLiteralValue) {
+                errors.err("initializing a struct requires array literal value", decl.value?.position ?: decl.position)
+                return super.visit(decl)
+            }
         }
 
         val existing = program.namespace.lookup(listOf(decl.name), decl)
         if (existing != null && existing !== decl)
             nameError(decl.name, decl.position, existing)
 
-        return super.visit(decl)
+        if(decl.definingBlock().name==decl.name)
+            nameError(decl.name, decl.position, decl.definingBlock())
+        if(decl.definingSubroutine()?.name==decl.name)
+            nameError(decl.name, decl.position, decl.definingSubroutine()!!)
+
+        super.visit(decl)
     }
 
-    override fun visit(subroutine: Subroutine): Statement {
-        if(subroutine.name in CompilationTarget.machine.opcodeNames) {
-            checkResult.add(NameError("can't use a cpu opcode name as a symbol: '${subroutine.name}'", subroutine.position))
+    override fun visit(subroutine: Subroutine) {
+        if(subroutine.name in CompilationTarget.instance.machine.opcodeNames) {
+            errors.err("can't use a cpu opcode name as a symbol: '${subroutine.name}'", subroutine.position)
         } else if(subroutine.name in BuiltinFunctions) {
             // the builtin functions can't be redefined
-            checkResult.add(NameError("builtin function cannot be redefined", subroutine.position))
+            errors.err("builtin function cannot be redefined", subroutine.position)
         } else {
             // already reported elsewhere:
             // if (subroutine.parameters.any { it.name in BuiltinFunctions })
@@ -117,14 +103,6 @@ internal class AstIdentifiersChecker(private val program: Program) : IAstModifyi
             if (existing != null && existing !== subroutine)
                 nameError(subroutine.name, subroutine.position, existing)
 
-            // does the parameter redefine a variable declared elsewhere?
-            for(param in subroutine.parameters) {
-                val existingVar = subroutine.lookup(listOf(param.name), subroutine)
-                if (existingVar != null && existingVar.parent !== subroutine) {
-                    nameError(param.name, param.position, existingVar)
-                }
-            }
-
             // check that there are no local variables, labels, or other subs that redefine the subroutine's parameters
             val symbolsInSub = subroutine.allDefinedSymbols()
             val namesInSub = symbolsInSub.map{ it.first }.toSet()
@@ -139,257 +117,50 @@ internal class AstIdentifiersChecker(private val program: Program) : IAstModifyi
                     nameError(name, sub.position, subroutine)
             }
 
-            // inject subroutine params as local variables (if they're not there yet) (for non-kernel subroutines and non-asm parameters)
-            // NOTE:
-            // - numeric types BYTE and WORD and FLOAT are passed by value;
-            // - strings, arrays, matrices are passed by reference (their 16-bit address is passed as an uword parameter)
-            if(subroutine.asmAddress==null) {
-                if(subroutine.asmParameterRegisters.isEmpty()) {
-                    subroutine.parameters
-                            .filter { it.name !in namesInSub }
-                            .forEach {
-                                val vardecl = VarDecl(VarDeclType.VAR, it.type, ZeropageWish.NOT_IN_ZEROPAGE, null, it.name, null, null,
-                                        isArray = false, autogeneratedDontRemove = true, position = subroutine.position)
-                                vardecl.linkParents(subroutine)
-                                subroutine.statements.add(0, vardecl)
-                            }
-                }
-            }
-
             if(subroutine.isAsmSubroutine && subroutine.statements.any{it !is InlineAssembly}) {
-                checkResult.add(SyntaxError("asmsub can only contain inline assembly (%asm)", subroutine.position))
+                errors.err("asmsub can only contain inline assembly (%asm)", subroutine.position)
             }
         }
-        return super.visit(subroutine)
+
+        super.visit(subroutine)
     }
 
-    override fun visit(label: Label): Statement {
-        if(label.name in CompilationTarget.machine.opcodeNames)
-            checkResult.add(NameError("can't use a cpu opcode name as a symbol: '${label.name}'", label.position))
+    override fun visit(label: Label) {
+        if(label.name in CompilationTarget.instance.machine.opcodeNames)
+            errors.err("can't use a cpu opcode name as a symbol: '${label.name}'", label.position)
 
         if(label.name in BuiltinFunctions) {
             // the builtin functions can't be redefined
-            checkResult.add(NameError("builtin function cannot be redefined", label.position))
+            errors.err("builtin function cannot be redefined", label.position)
         } else {
-            val existing = program.namespace.lookup(listOf(label.name), label)
-            if (existing != null && existing !== label)
-                nameError(label.name, label.position, existing)
-        }
-        return super.visit(label)
-    }
-
-    override fun visit(forLoop: ForLoop): Statement {
-        // If the for loop has a decltype, it means to declare the loopvar inside the loop body
-        // rather than reusing an already declared loopvar from an outer scope.
-        // For loops that loop over an interable variable (instead of a range of numbers) get an
-        // additional interation count variable in their scope.
-        if(forLoop.loopRegister!=null) {
-            if(forLoop.loopRegister == Register.X)
-                printWarning("writing to the X register is dangerous, because it's used as an internal pointer", forLoop.position)
-        } else {
-            val loopVar = forLoop.loopVar
-            if (loopVar != null) {
-                val validName = forLoop.body.name.replace("<", "").replace(">", "").replace("-", "")
-                val loopvarName = "prog8_loopvar_$validName"
-                if (forLoop.iterable !is RangeExpr) {
-                    val existing = if (forLoop.body.containsNoCodeNorVars()) null else forLoop.body.lookup(listOf(loopvarName), forLoop.body.statements.first())
-                    if (existing == null) {
-                        // create loop iteration counter variable (without value, to avoid an assignment)
-                        val vardecl = VarDecl(VarDeclType.VAR, DataType.UBYTE, ZeropageWish.PREFER_ZEROPAGE, null, loopvarName, null, null,
-                                isArray = false, autogeneratedDontRemove = true, position = loopVar.position)
-                        vardecl.linkParents(forLoop.body)
-                        forLoop.body.statements.add(0, vardecl)
-                        loopVar.parent = forLoop.body   // loopvar 'is defined in the body'
-                    }
+            val existing = label.definingSubroutine()?.getAllLabels(label.name) ?: emptyList()
+            for(el in existing) {
+                if(el === label || el.name != label.name)
+                    continue
+                else {
+                    nameError(label.name, label.position, el)
+                    break
                 }
             }
         }
-        return super.visit(forLoop)
+
+        super.visit(label)
     }
 
-    override fun visit(assignTarget: AssignTarget): AssignTarget {
-        if(assignTarget.register== Register.X)
-            printWarning("writing to the X register is dangerous, because it's used as an internal pointer", assignTarget.position)
-        return super.visit(assignTarget)
+    override fun visit(string: StringLiteralValue) {
+        if (string.value.length > 255)
+            errors.err("string literal length max is 255", string.position)
+
+        super.visit(string)
     }
 
-    override fun visit(returnStmt: Return): Statement {
-        if(returnStmt.value!=null) {
-            // possibly adjust any literal values returned, into the desired returning data type
-            val subroutine = returnStmt.definingSubroutine()!!
-            if(subroutine.returntypes.size!=1)
-                return returnStmt  // mismatch in number of return values, error will be printed later.
-            val lval = returnStmt.value as? NumericLiteralValue
-            returnStmt.value = lval?.cast(subroutine.returntypes.single()) ?: returnStmt.value!!
-        }
-        return super.visit(returnStmt)
-    }
-
-    override fun visit(arrayLiteral: ArrayLiteralValue): Expression {
-        val array = super.visit(arrayLiteral)
-        if(array is ArrayLiteralValue) {
-            val vardecl = array.parent as? VarDecl
-            return if(vardecl!=null)
-                fixupArrayEltDatatypesFromVardecl(array, vardecl)
-            else {
-                // fix the datatype of the array (also on the heap) to the 'biggest' datatype in the array
-                // (we don't know the desired datatype here exactly so we guess)
-                val datatype = determineArrayDt(array.value)
-                val litval2 = array.cast(datatype)
-                if(litval2!=null) {
-                    litval2.parent = array.parent
-                    // finally, replace the literal array by a identifier reference.
-                    makeIdentifierFromRefLv(litval2)
-                } else array
-            }
-        }
-        return array
-    }
-
-    override fun visit(stringLiteral: StringLiteralValue): Expression {
-        val string = super.visit(stringLiteral)
-        if(string is StringLiteralValue) {
-            val vardecl = string.parent as? VarDecl
-            // intern the string; move it into the heap
-            if (string.value.length !in 1..255)
-                checkResult.add(ExpressionError("string literal length must be between 1 and 255", string.position))
-            return if (vardecl != null)
-                string
-            else
-                makeIdentifierFromRefLv(string)  // replace the literal string by a identifier reference.
-        }
-        return string
-    }
-
-    private fun determineArrayDt(array: Array<Expression>): DataType {
-        val datatypesInArray = array.map { it.inferType(program) }
-        require(datatypesInArray.isNotEmpty() && datatypesInArray.all { it.isKnown }) { "can't determine type of empty array" }
-        val dts = datatypesInArray.map { it.typeOrElse(DataType.STRUCT) }
-        return when {
-            DataType.FLOAT in dts -> DataType.ARRAY_F
-            DataType.WORD in dts -> DataType.ARRAY_W
-            DataType.UWORD in dts -> DataType.ARRAY_UW
-            DataType.BYTE in dts -> DataType.ARRAY_B
-            DataType.UBYTE in dts -> DataType.ARRAY_UB
-            else -> throw IllegalArgumentException("can't determine type of array")
-        }
-    }
-
-    private fun makeIdentifierFromRefLv(array: ArrayLiteralValue): IdentifierReference {
-        // a referencetype literal value that's not declared as a variable
-        // we need to introduce an auto-generated variable for this to be able to refer to the value
-        // note: if the var references the same literal value, it is not yet de-duplicated here.
-        val scope = array.definingScope()
-        val variable = VarDecl.createAuto(array)
-        return replaceWithIdentifier(variable, scope, array.parent)
-    }
-
-    private fun makeIdentifierFromRefLv(string: StringLiteralValue): IdentifierReference {
-        // a referencetype literal value that's not declared as a variable
-        // we need to introduce an auto-generated variable for this to be able to refer to the value
-        // note: if the var references the same literal value, it is not yet de-duplicated here.
-        val scope = string.definingScope()
-        val variable = VarDecl.createAuto(string)
-        return replaceWithIdentifier(variable, scope, string.parent)
-    }
-
-    private fun replaceWithIdentifier(variable: VarDecl, scope: INameScope, parent: Node): IdentifierReference {
-        val variable1 = addVarDecl(scope, variable)
-        // replace the reference literal by a identifier reference
-        val identifier = IdentifierReference(listOf(variable1.name), variable1.position)
-        identifier.parent = parent
-        return identifier
-    }
-
-    override fun visit(structDecl: StructDecl): Statement {
+    override fun visit(structDecl: StructDecl) {
         for(member in structDecl.statements){
             val decl = member as? VarDecl
             if(decl!=null && decl.datatype !in NumericDatatypes)
-                checkResult.add(SyntaxError("structs can only contain numerical types", decl.position))
+                errors.err("structs can only contain numerical types", decl.position)
         }
 
-        return super.visit(structDecl)
+        super.visit(structDecl)
     }
-
-    override fun visit(expr: BinaryExpression): Expression {
-        return when {
-            expr.left is StringLiteralValue ->
-                processBinaryExprWithString(expr.left as StringLiteralValue, expr.right, expr)
-            expr.right is StringLiteralValue ->
-                processBinaryExprWithString(expr.right as StringLiteralValue, expr.left, expr)
-            else -> super.visit(expr)
-        }
-    }
-
-    private fun processBinaryExprWithString(string: StringLiteralValue, operand: Expression, expr: BinaryExpression): Expression {
-        val constvalue = operand.constValue(program)
-        if(constvalue!=null) {
-            if (expr.operator == "*") {
-                // repeat a string a number of times
-                return StringLiteralValue(string.value.repeat(constvalue.number.toInt()), expr.position)
-            }
-        }
-        if(expr.operator == "+" && operand is StringLiteralValue) {
-            // concatenate two strings
-            return StringLiteralValue("${string.value}${operand.value}", expr.position)
-        }
-        return expr
-    }
-
-    private fun addVarDecl(scope: INameScope, variable: VarDecl): VarDecl {
-        if(scope !in vardeclsToAdd)
-            vardeclsToAdd[scope] = mutableListOf()
-        val declList = vardeclsToAdd.getValue(scope)
-        val existing = declList.singleOrNull { it.name==variable.name }
-        return if(existing!=null) {
-            existing
-        } else {
-            declList.add(variable)
-            variable
-        }
-    }
-
-}
-
-internal fun fixupArrayEltDatatypes(array: ArrayLiteralValue, program: Program): ArrayLiteralValue {
-    val dts = array.value.map {it.inferType(program).typeOrElse(DataType.STRUCT)}.toSet()
-    if(dts.any { it !in NumericDatatypes }) {
-        return array
-    }
-    val dt = when {
-        DataType.FLOAT in dts -> DataType.ARRAY_F
-        DataType.WORD in dts -> DataType.ARRAY_W
-        DataType.UWORD in dts -> DataType.ARRAY_UW
-        DataType.BYTE in dts -> DataType.ARRAY_B
-        else -> DataType.ARRAY_UB
-    }
-    if(dt==array.type)
-        return array
-
-    // convert values and array type
-    val elementType = ArrayElementTypes.getValue(dt)
-    val allNumerics = array.value.all { it is NumericLiteralValue }
-    if(allNumerics) {
-        val values = array.value.map { (it as NumericLiteralValue).cast(elementType) as Expression }.toTypedArray()
-        val array2 = ArrayLiteralValue(dt, values, array.position)
-        array2.linkParents(array.parent)
-        return array2
-    }
-
-    return array
-}
-
-internal fun fixupArrayEltDatatypesFromVardecl(array: ArrayLiteralValue, vardecl: VarDecl): ArrayLiteralValue {
-    val arrayDt = array.type
-    if(arrayDt!=vardecl.datatype) {
-        // fix the datatype of the array (also on the heap) to match the vardecl
-        val cast = array.cast(vardecl.datatype)
-        if (cast != null) {
-            vardecl.value = cast
-            cast.linkParents(vardecl)
-            return cast
-        }
-        // can't be casted yet, attempt again later
-    }
-    return array
 }

compiler/src/prog8/ast/processing/AstRecursionChecker.kt

@@ -1,117 +0,0 @@
-package prog8.ast.processing
-
-import prog8.ast.INameScope
-import prog8.ast.base.AstException
-import prog8.ast.expressions.FunctionCall
-import prog8.ast.statements.FunctionCallStatement
-import prog8.ast.statements.Subroutine
-
-
-internal class AstRecursionChecker(private val namespace: INameScope) : IAstVisitor {
-    private val callGraph = DirectedGraph<INameScope>()
-
-    internal fun result(): List<AstException> {
-        val cycle = callGraph.checkForCycle()
-        if(cycle.isEmpty())
-            return emptyList()
-        val chain = cycle.joinToString(" <-- ") { "${it.name} at ${it.position}" }
-        return listOf(AstException("Program contains recursive subroutine calls, this is not supported. Recursive chain:\n (a subroutine call in) $chain"))
-    }
-
-    override fun visit(functionCallStatement: FunctionCallStatement) {
-        val scope = functionCallStatement.definingScope()
-        val targetStatement = functionCallStatement.target.targetStatement(namespace)
-        if(targetStatement!=null) {
-            val targetScope = when (targetStatement) {
-                is Subroutine -> targetStatement
-                else -> targetStatement.definingScope()
-            }
-            callGraph.add(scope, targetScope)
-        }
-        super.visit(functionCallStatement)
-    }
-
-    override fun visit(functionCall: FunctionCall) {
-        val scope = functionCall.definingScope()
-        val targetStatement = functionCall.target.targetStatement(namespace)
-        if(targetStatement!=null) {
-            val targetScope = when (targetStatement) {
-                is Subroutine -> targetStatement
-                else -> targetStatement.definingScope()
-            }
-            callGraph.add(scope, targetScope)
-        }
-        super.visit(functionCall)
-    }
-
-
-    private class DirectedGraph<VT> {
-        private val graph = mutableMapOf<VT, MutableSet<VT>>()
-        private var uniqueVertices = mutableSetOf<VT>()
-        val numVertices : Int
-            get() = uniqueVertices.size
-
-        fun add(from: VT, to: VT) {
-            var targets = graph[from]
-            if(targets==null) {
-                targets = mutableSetOf()
-                graph[from] = targets
-            }
-            targets.add(to)
-            uniqueVertices.add(from)
-            uniqueVertices.add(to)
-        }
-
-        fun print() {
-            println("#vertices: $numVertices")
-            graph.forEach { (from, to) ->
-                println("$from   CALLS:")
-                to.forEach { println("   $it") }
-            }
-            val cycle = checkForCycle()
-            if(cycle.isNotEmpty()) {
-                println("CYCLIC!  $cycle")
-            }
-        }
-
-        fun checkForCycle(): MutableList<VT> {
-            val visited = uniqueVertices.associateWith { false }.toMutableMap()
-            val recStack = uniqueVertices.associateWith { false }.toMutableMap()
-            val cycle = mutableListOf<VT>()
-            for(node in uniqueVertices) {
-                if(isCyclicUntil(node, visited, recStack, cycle))
-                    return cycle
-            }
-            return mutableListOf()
-        }
-
-        private fun isCyclicUntil(node: VT,
-                                  visited: MutableMap<VT, Boolean>,
-                                  recStack: MutableMap<VT, Boolean>,
-                                  cycleNodes: MutableList<VT>): Boolean {
-
-            if(recStack[node]==true) return true
-            if(visited[node]==true) return false
-
-            // mark current node as visited and add to recursion stack
-            visited[node] = true
-            recStack[node] = true
-
-            // recurse for all neighbours
-            val neighbors = graph[node]
-            if(neighbors!=null) {
-                for (neighbour in neighbors) {
-                    if (isCyclicUntil(neighbour, visited, recStack, cycleNodes)) {
-                        cycleNodes.add(node)
-                        return true
-                    }
-                }
-            }
-
-            // pop node from recursion stack
-            recStack[node] = false
-            return false
-        }
-    }
-
-}

compiler/src/prog8/ast/processing/AstVariousTransforms.kt

@@ -0,0 +1,105 @@
+package prog8.ast.processing
+
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.statements.*
+
+
+internal class AstVariousTransforms(private val program: Program) : AstWalker() {
+    private val noModifications = emptyList<IAstModification>()
+
+    override fun before(decl: VarDecl, parent: Node): Iterable<IAstModification> {
+        // is it a struct variable? then define all its struct members as mangled names,
+        //    and include the original decl as well.
+        if(decl.datatype==DataType.STRUCT && !decl.structHasBeenFlattened) {
+            val decls = decl.flattenStructMembers()
+            decls.add(decl)
+            val result = AnonymousScope(decls, decl.position)
+            return listOf(IAstModification.ReplaceNode(
+                    decl, result, parent
+            ))
+        }
+
+        return noModifications
+    }
+
+    override fun after(subroutine: Subroutine, parent: Node): Iterable<IAstModification> {
+        // For non-kernel subroutines and non-asm parameters:
+        // inject subroutine params as local variables (if they're not there yet).
+        val symbolsInSub = subroutine.allDefinedSymbols()
+        val namesInSub = symbolsInSub.map{ it.first }.toSet()
+        if(subroutine.asmAddress==null) {
+            if(subroutine.asmParameterRegisters.isEmpty() && subroutine.parameters.isNotEmpty()) {
+                val vars = subroutine.statements.filterIsInstance<VarDecl>().map { it.name }.toSet()
+                if(!vars.containsAll(subroutine.parameters.map{it.name})) {
+                    return subroutine.parameters
+                            .filter { it.name !in namesInSub }
+                            .map {
+                                val vardecl = ParameterVarDecl(it.name, it.type, subroutine.position)
+                                IAstModification.InsertFirst(vardecl, subroutine)
+                            }
+                }
+            }
+        }
+
+        return noModifications
+    }
+
+    override fun after(expr: BinaryExpression, parent: Node): Iterable<IAstModification> {
+        val leftStr = expr.left as? StringLiteralValue
+        val rightStr = expr.right as? StringLiteralValue
+        if(expr.operator == "+") {
+            val concatenatedString = concatString(expr)
+            if(concatenatedString!=null)
+                return listOf(IAstModification.ReplaceNode(expr, concatenatedString, parent))
+        }
+        else if(expr.operator == "*") {
+            if (leftStr!=null) {
+                val amount = expr.right.constValue(program)
+                if(amount!=null) {
+                    val string = leftStr.value.repeat(amount.number.toInt())
+                    val strval = StringLiteralValue(string, leftStr.altEncoding, expr.position)
+                    return listOf(IAstModification.ReplaceNode(expr, strval, parent))
+                }
+            }
+            else if (rightStr!=null) {
+                val amount = expr.right.constValue(program)
+                if(amount!=null) {
+                    val string = rightStr.value.repeat(amount.number.toInt())
+                    val strval = StringLiteralValue(string, rightStr.altEncoding, expr.position)
+                    return listOf(IAstModification.ReplaceNode(expr, strval, parent))
+                }
+            }
+        }
+
+        return noModifications
+    }
+
+    private fun concatString(expr: BinaryExpression): StringLiteralValue? {
+        val rightStrval = expr.right as? StringLiteralValue
+        val leftStrval = expr.left as? StringLiteralValue
+        return when {
+            expr.operator!="+" -> null
+            expr.left is BinaryExpression && rightStrval!=null -> {
+                val subStrVal = concatString(expr.left as BinaryExpression)
+                if(subStrVal==null)
+                    null
+                else
+                    StringLiteralValue("${subStrVal.value}${rightStrval.value}", subStrVal.altEncoding, rightStrval.position)
+            }
+            expr.right is BinaryExpression && leftStrval!=null -> {
+                val subStrVal = concatString(expr.right as BinaryExpression)
+                if(subStrVal==null)
+                    null
+                else
+                    StringLiteralValue("${leftStrval.value}${subStrVal.value}", subStrVal.altEncoding, leftStrval.position)
+            }
+            leftStrval!=null && rightStrval!=null -> {
+                StringLiteralValue("${leftStrval.value}${rightStrval.value}", leftStrval.altEncoding, leftStrval.position)
+            }
+            else -> null
+        }
+    }
+}

compiler/src/prog8/ast/processing/AstWalker.kt

@@ -0,0 +1,424 @@
+package prog8.ast.processing
+
+import prog8.ast.*
+import prog8.ast.base.FatalAstException
+import prog8.ast.expressions.*
+import prog8.ast.statements.*
+
+
+interface IAstModification {
+    fun perform()
+
+    class Remove(val node: Node, val parent: INameScope) : IAstModification {
+        override fun perform() {
+            if (!parent.statements.remove(node) && parent !is GlobalNamespace)
+                throw FatalAstException("attempt to remove non-existing node $node")
+        }
+    }
+
+    class SetExpression(private val setter: (newExpr: Expression) -> Unit, private val newExpr: Expression, private val parent: Node) : IAstModification {
+        override fun perform() {
+            setter(newExpr)
+            newExpr.linkParents(parent)
+        }
+    }
+
+    class InsertFirst(private val stmt: Statement, private val parent: INameScope) : IAstModification {
+        override fun perform() {
+            parent.statements.add(0, stmt)
+            stmt.linkParents(parent as Node)
+        }
+    }
+
+    class InsertLast(private val stmt: Statement, private val parent: INameScope) : IAstModification {
+        override fun perform() {
+            parent.statements.add(stmt)
+            stmt.linkParents(parent as Node)
+        }
+    }
+
+    class InsertAfter(private val after: Statement, private val stmt: Statement, private val parent: INameScope) : IAstModification {
+        override fun perform() {
+            val idx = parent.statements.indexOfFirst { it===after } + 1
+            parent.statements.add(idx, stmt)
+            stmt.linkParents(parent as Node)
+        }
+    }
+
+    class InsertBefore(private val before: Statement, private val stmt: Statement, private val parent: INameScope) : IAstModification {
+        override fun perform() {
+            val idx = parent.statements.indexOfFirst { it===before }
+            parent.statements.add(idx, stmt)
+            stmt.linkParents(parent as Node)
+        }
+    }
+
+    class ReplaceNode(private val node: Node, private val replacement: Node, private val parent: Node) : IAstModification {
+        override fun perform() {
+            parent.replaceChildNode(node, replacement)
+            replacement.linkParents(parent)
+        }
+    }
+
+    class SwapOperands(private val expr: BinaryExpression): IAstModification {
+        override fun perform() {
+            require(expr.operator in associativeOperators)
+            val tmp = expr.left
+            expr.left = expr.right
+            expr.right = tmp
+        }
+    }
+}
+
+
+abstract class AstWalker {
+    open fun before(addressOf: AddressOf, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(array: ArrayLiteralValue, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(arrayIndexedExpression: ArrayIndexedExpression, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(assignTarget: AssignTarget, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(assignment: Assignment, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(block: Block, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(branchStatement: BranchStatement, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(breakStmt: Break, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(builtinFunctionStatementPlaceholder: BuiltinFunctionStatementPlaceholder, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(decl: VarDecl, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(directive: Directive, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(expr: BinaryExpression, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(expr: PrefixExpression, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(forLoop: ForLoop, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(repeatLoop: RepeatLoop, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(functionCall: FunctionCall, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(functionCallStatement: FunctionCallStatement, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(identifier: IdentifierReference, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(ifStatement: IfStatement, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(inlineAssembly: InlineAssembly, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(jump: Jump, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(label: Label, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(memread: DirectMemoryRead, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(memwrite: DirectMemoryWrite, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(module: Module, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(nopStatement: NopStatement, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(numLiteral: NumericLiteralValue, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(postIncrDecr: PostIncrDecr, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(program: Program, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(range: RangeExpr, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(untilLoop: UntilLoop, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(returnStmt: Return, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(scope: AnonymousScope, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(string: StringLiteralValue, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(structDecl: StructDecl, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(subroutine: Subroutine, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(typecast: TypecastExpression, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(whenChoice: WhenChoice, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(whenStatement: WhenStatement, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun before(whileLoop: WhileLoop, parent: Node): Iterable<IAstModification> = emptyList()
+
+    open fun after(addressOf: AddressOf, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(array: ArrayLiteralValue, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(arrayIndexedExpression: ArrayIndexedExpression, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(assignTarget: AssignTarget, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(assignment: Assignment, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(block: Block, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(branchStatement: BranchStatement, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(breakStmt: Break, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(builtinFunctionStatementPlaceholder: BuiltinFunctionStatementPlaceholder, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(directive: Directive, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(expr: BinaryExpression, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(expr: PrefixExpression, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(forLoop: ForLoop, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(repeatLoop: RepeatLoop, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(functionCall: FunctionCall, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(functionCallStatement: FunctionCallStatement, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(identifier: IdentifierReference, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(ifStatement: IfStatement, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(inlineAssembly: InlineAssembly, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(jump: Jump, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(label: Label, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(memread: DirectMemoryRead, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(memwrite: DirectMemoryWrite, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(module: Module, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(nopStatement: NopStatement, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(numLiteral: NumericLiteralValue, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(postIncrDecr: PostIncrDecr, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(program: Program, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(range: RangeExpr, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(untilLoop: UntilLoop, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(returnStmt: Return, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(scope: AnonymousScope, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(string: StringLiteralValue, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(structDecl: StructDecl, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(subroutine: Subroutine, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(typecast: TypecastExpression, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(whenChoice: WhenChoice, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(whenStatement: WhenStatement, parent: Node): Iterable<IAstModification> = emptyList()
+    open fun after(whileLoop: WhileLoop, parent: Node): Iterable<IAstModification> = emptyList()
+
+    private val modifications = mutableListOf<Triple<IAstModification, Node, Node>>()
+
+    private fun track(mods: Iterable<IAstModification>, node: Node, parent: Node) {
+        for (it in mods) modifications += Triple(it, node, parent)
+    }
+
+    fun applyModifications(): Int {
+        modifications.forEach {
+            it.first.perform()
+        }
+        val amount = modifications.size
+        modifications.clear()
+        return amount
+    }
+
+    fun visit(program: Program) {
+        track(before(program, program), program, program)
+        program.modules.forEach { it.accept(this, program) }
+        track(after(program, program), program, program)
+    }
+
+    fun visit(module: Module, parent: Node) {
+        track(before(module, parent), module, parent)
+        module.statements.forEach{ it.accept(this, module) }
+        track(after(module, parent), module, parent)
+    }
+
+    fun visit(expr: PrefixExpression, parent: Node) {
+        track(before(expr, parent), expr, parent)
+        expr.expression.accept(this, expr)
+        track(after(expr, parent), expr, parent)
+    }
+
+    fun visit(expr: BinaryExpression, parent: Node) {
+        track(before(expr, parent), expr, parent)
+        expr.left.accept(this, expr)
+        expr.right.accept(this, expr)
+        track(after(expr, parent), expr, parent)
+    }
+
+    fun visit(directive: Directive, parent: Node) {
+        track(before(directive, parent), directive, parent)
+        track(after(directive, parent), directive, parent)
+    }
+
+    fun visit(block: Block, parent: Node) {
+        track(before(block, parent), block, parent)
+        block.statements.forEach { it.accept(this, block) }
+        track(after(block, parent), block, parent)
+    }
+
+    fun visit(decl: VarDecl, parent: Node) {
+        track(before(decl, parent), decl, parent)
+        decl.value?.accept(this, decl)
+        decl.arraysize?.accept(this, decl)
+        decl.struct?.accept(this, decl)
+        track(after(decl, parent), decl, parent)
+    }
+
+    fun visit(subroutine: Subroutine, parent: Node) {
+        track(before(subroutine, parent), subroutine, parent)
+        subroutine.statements.forEach { it.accept(this, subroutine) }
+        track(after(subroutine, parent), subroutine, parent)
+    }
+
+    fun visit(functionCall: FunctionCall, parent: Node) {
+        track(before(functionCall, parent), functionCall, parent)
+        functionCall.target.accept(this, functionCall)
+        functionCall.args.forEach { it.accept(this, functionCall) }
+        track(after(functionCall, parent), functionCall, parent)
+    }
+
+    fun visit(functionCallStatement: FunctionCallStatement, parent: Node) {
+        track(before(functionCallStatement, parent), functionCallStatement, parent)
+        functionCallStatement.target.accept(this, functionCallStatement)
+        functionCallStatement.args.forEach { it.accept(this, functionCallStatement) }
+        track(after(functionCallStatement, parent), functionCallStatement, parent)
+    }
+
+    fun visit(identifier: IdentifierReference, parent: Node) {
+        track(before(identifier, parent), identifier, parent)
+        track(after(identifier, parent), identifier, parent)
+    }
+
+    fun visit(jump: Jump, parent: Node) {
+        track(before(jump, parent), jump, parent)
+        jump.identifier?.accept(this, jump)
+        track(after(jump, parent), jump, parent)
+    }
+
+    fun visit(ifStatement: IfStatement, parent: Node) {
+        track(before(ifStatement, parent), ifStatement, parent)
+        ifStatement.condition.accept(this, ifStatement)
+        ifStatement.truepart.accept(this, ifStatement)
+        ifStatement.elsepart.accept(this, ifStatement)
+        track(after(ifStatement, parent), ifStatement, parent)
+    }
+
+    fun visit(branchStatement: BranchStatement, parent: Node) {
+        track(before(branchStatement, parent), branchStatement, parent)
+        branchStatement.truepart.accept(this, branchStatement)
+        branchStatement.elsepart.accept(this, branchStatement)
+        track(after(branchStatement, parent), branchStatement, parent)
+    }
+
+    fun visit(range: RangeExpr, parent: Node) {
+        track(before(range, parent), range, parent)
+        range.from.accept(this, range)
+        range.to.accept(this, range)
+        range.step.accept(this, range)
+        track(after(range, parent), range, parent)
+    }
+
+    fun visit(label: Label, parent: Node) {
+        track(before(label, parent), label, parent)
+        track(after(label, parent), label, parent)
+    }
+
+    fun visit(numLiteral: NumericLiteralValue, parent: Node) {
+        track(before(numLiteral, parent), numLiteral, parent)
+        track(after(numLiteral, parent), numLiteral, parent)
+    }
+
+    fun visit(string: StringLiteralValue, parent: Node) {
+        track(before(string, parent), string, parent)
+        track(after(string, parent), string, parent)
+    }
+
+    fun visit(array: ArrayLiteralValue, parent: Node) {
+        track(before(array, parent), array, parent)
+        array.value.forEach { v->v.accept(this, array) }
+        track(after(array, parent), array, parent)
+    }
+
+    fun visit(assignment: Assignment, parent: Node) {
+        track(before(assignment, parent), assignment, parent)
+        assignment.target.accept(this, assignment)
+        assignment.value.accept(this, assignment)
+        track(after(assignment, parent), assignment, parent)
+    }
+
+    fun visit(postIncrDecr: PostIncrDecr, parent: Node) {
+        track(before(postIncrDecr, parent), postIncrDecr, parent)
+        postIncrDecr.target.accept(this, postIncrDecr)
+        track(after(postIncrDecr, parent), postIncrDecr, parent)
+    }
+
+    fun visit(breakStmt: Break, parent: Node) {
+        track(before(breakStmt, parent), breakStmt, parent)
+        track(after(breakStmt, parent), breakStmt, parent)
+    }
+
+    fun visit(forLoop: ForLoop, parent: Node) {
+        track(before(forLoop, parent), forLoop, parent)
+        forLoop.loopVar.accept(this, forLoop)
+        forLoop.iterable.accept(this, forLoop)
+        forLoop.body.accept(this, forLoop)
+        track(after(forLoop, parent), forLoop, parent)
+    }
+
+    fun visit(whileLoop: WhileLoop, parent: Node) {
+        track(before(whileLoop, parent), whileLoop, parent)
+        whileLoop.condition.accept(this, whileLoop)
+        whileLoop.body.accept(this, whileLoop)
+        track(after(whileLoop, parent), whileLoop, parent)
+    }
+
+    fun visit(repeatLoop: RepeatLoop, parent: Node) {
+        track(before(repeatLoop, parent), repeatLoop, parent)
+        repeatLoop.iterations?.accept(this, repeatLoop)
+        repeatLoop.body.accept(this, repeatLoop)
+        track(after(repeatLoop, parent), repeatLoop, parent)
+    }
+
+    fun visit(untilLoop: UntilLoop, parent: Node) {
+        track(before(untilLoop, parent), untilLoop, parent)
+        untilLoop.condition.accept(this, untilLoop)
+        untilLoop.body.accept(this, untilLoop)
+        track(after(untilLoop, parent), untilLoop, parent)
+    }
+
+    fun visit(returnStmt: Return, parent: Node) {
+        track(before(returnStmt, parent), returnStmt, parent)
+        returnStmt.value?.accept(this, returnStmt)
+        track(after(returnStmt, parent), returnStmt, parent)
+    }
+
+    fun visit(arrayIndexedExpression: ArrayIndexedExpression, parent: Node) {
+        track(before(arrayIndexedExpression, parent), arrayIndexedExpression, parent)
+        arrayIndexedExpression.arrayvar.accept(this, arrayIndexedExpression)
+        arrayIndexedExpression.indexer.accept(this, arrayIndexedExpression)
+        track(after(arrayIndexedExpression, parent), arrayIndexedExpression, parent)
+    }
+
+    fun visit(assignTarget: AssignTarget, parent: Node) {
+        track(before(assignTarget, parent), assignTarget, parent)
+        assignTarget.arrayindexed?.accept(this, assignTarget)
+        assignTarget.identifier?.accept(this, assignTarget)
+        assignTarget.memoryAddress?.accept(this, assignTarget)
+        track(after(assignTarget, parent), assignTarget, parent)
+    }
+
+    fun visit(scope: AnonymousScope, parent: Node) {
+        track(before(scope, parent), scope, parent)
+        scope.statements.forEach { it.accept(this, scope) }
+        track(after(scope, parent), scope, parent)
+    }
+
+    fun visit(typecast: TypecastExpression, parent: Node) {
+        track(before(typecast, parent), typecast, parent)
+        typecast.expression.accept(this, typecast)
+        track(after(typecast, parent), typecast, parent)
+    }
+
+    fun visit(memread: DirectMemoryRead, parent: Node) {
+        track(before(memread, parent), memread, parent)
+        memread.addressExpression.accept(this, memread)
+        track(after(memread, parent), memread, parent)
+    }
+
+    fun visit(memwrite: DirectMemoryWrite, parent: Node) {
+        track(before(memwrite, parent), memwrite, parent)
+        memwrite.addressExpression.accept(this, memwrite)
+        track(after(memwrite, parent), memwrite, parent)
+    }
+
+    fun visit(addressOf: AddressOf, parent: Node) {
+        track(before(addressOf, parent), addressOf, parent)
+        addressOf.identifier.accept(this, addressOf)
+        track(after(addressOf, parent), addressOf, parent)
+    }
+
+    fun visit(inlineAssembly: InlineAssembly, parent: Node) {
+        track(before(inlineAssembly, parent), inlineAssembly, parent)
+        track(after(inlineAssembly, parent), inlineAssembly, parent)
+    }
+
+    fun visit(builtinFunctionStatementPlaceholder: BuiltinFunctionStatementPlaceholder, parent: Node) {
+        track(before(builtinFunctionStatementPlaceholder, parent), builtinFunctionStatementPlaceholder, parent)
+        track(after(builtinFunctionStatementPlaceholder, parent), builtinFunctionStatementPlaceholder, parent)
+    }
+
+    fun visit(nopStatement: NopStatement, parent: Node) {
+        track(before(nopStatement, parent), nopStatement, parent)
+        track(after(nopStatement, parent), nopStatement, parent)
+    }
+
+    fun visit(whenStatement: WhenStatement, parent: Node) {
+        track(before(whenStatement, parent), whenStatement, parent)
+        whenStatement.condition.accept(this, whenStatement)
+        whenStatement.choices.forEach { it.accept(this, whenStatement) }
+        track(after(whenStatement, parent), whenStatement, parent)
+    }
+
+    fun visit(whenChoice: WhenChoice, parent: Node) {
+        track(before(whenChoice, parent), whenChoice, parent)
+        whenChoice.values?.forEach { it.accept(this, whenChoice) }
+        whenChoice.statements.accept(this, whenChoice)
+        track(after(whenChoice, parent), whenChoice, parent)
+    }
+
+    fun visit(structDecl: StructDecl, parent: Node) {
+        track(before(structDecl, parent), structDecl, parent)
+        structDecl.statements.forEach { it.accept(this, structDecl) }
+        track(after(structDecl, parent), structDecl, parent)
+    }
+}
+

compiler/src/prog8/ast/processing/IAstModifyingVisitor.kt

@@ -1,261 +0,0 @@
-package prog8.ast.processing
-
-import prog8.ast.Module
-import prog8.ast.Program
-import prog8.ast.base.FatalAstException
-import prog8.ast.expressions.*
-import prog8.ast.statements.*
-
-interface IAstModifyingVisitor {
-    fun visit(program: Program) {
-        program.modules.forEach { visit(it) }
-    }
-
-    fun visit(module: Module) {
-        module.statements = module.statements.map { it.accept(this) }.toMutableList()
-    }
-
-    fun visit(expr: PrefixExpression): Expression {
-        expr.expression = expr.expression.accept(this)
-        return expr
-    }
-
-    fun visit(expr: BinaryExpression): Expression {
-        expr.left = expr.left.accept(this)
-        expr.right = expr.right.accept(this)
-        return expr
-    }
-
-    fun visit(directive: Directive): Statement {
-        return directive
-    }
-
-    fun visit(block: Block): Statement {
-        block.statements = block.statements.map { it.accept(this) }.toMutableList()
-        return block
-    }
-
-    fun visit(decl: VarDecl): Statement {
-        decl.value = decl.value?.accept(this)
-        decl.arraysize?.accept(this)
-        return decl
-    }
-
-    fun visit(subroutine: Subroutine): Statement {
-        subroutine.statements = subroutine.statements.map { it.accept(this) }.toMutableList()
-        return subroutine
-    }
-
-    fun visit(functionCall: FunctionCall): Expression {
-        val newtarget = functionCall.target.accept(this)
-        if(newtarget is IdentifierReference)
-            functionCall.target = newtarget
-        else
-            throw FatalAstException("cannot change class of function call target")
-        functionCall.args = functionCall.args.map { it.accept(this) }.toMutableList()
-        return functionCall
-    }
-
-    fun visit(functionCallStatement: FunctionCallStatement): Statement {
-        val newtarget = functionCallStatement.target.accept(this)
-        if(newtarget is IdentifierReference)
-            functionCallStatement.target = newtarget
-        else
-            throw FatalAstException("cannot change class of function call target")
-        functionCallStatement.args = functionCallStatement.args.map { it.accept(this) }.toMutableList()
-        return functionCallStatement
-    }
-
-    fun visit(identifier: IdentifierReference): Expression {
-        // note: this is an identifier that is used in an expression.
-        // other identifiers are simply part of the other statements (such as jumps, subroutine defs etc)
-        return identifier
-    }
-
-    fun visit(jump: Jump): Statement {
-        if(jump.identifier!=null) {
-            val ident = jump.identifier.accept(this)
-            if(ident is IdentifierReference && ident!==jump.identifier) {
-                return Jump(null, ident, null, jump.position)
-            }
-        }
-        return jump
-    }
-
-    fun visit(ifStatement: IfStatement): Statement {
-        ifStatement.condition = ifStatement.condition.accept(this)
-        ifStatement.truepart = ifStatement.truepart.accept(this) as AnonymousScope
-        ifStatement.elsepart = ifStatement.elsepart.accept(this) as AnonymousScope
-        return ifStatement
-    }
-
-    fun visit(branchStatement: BranchStatement): Statement {
-        branchStatement.truepart = branchStatement.truepart.accept(this) as AnonymousScope
-        branchStatement.elsepart = branchStatement.elsepart.accept(this) as AnonymousScope
-        return branchStatement
-    }
-
-    fun visit(range: RangeExpr): Expression {
-        range.from = range.from.accept(this)
-        range.to = range.to.accept(this)
-        range.step = range.step.accept(this)
-        return range
-    }
-
-    fun visit(label: Label): Statement {
-        return label
-    }
-
-    fun visit(literalValue: NumericLiteralValue): NumericLiteralValue {
-        return literalValue
-    }
-
-    fun visit(stringLiteral: StringLiteralValue): Expression {
-        return stringLiteral
-    }
-
-    fun visit(arrayLiteral: ArrayLiteralValue): Expression {
-        for(av in arrayLiteral.value.withIndex()) {
-            val newvalue = av.value.accept(this)
-            arrayLiteral.value[av.index] = newvalue
-        }
-        return arrayLiteral
-    }
-
-    fun visit(assignment: Assignment): Statement {
-        assignment.target = assignment.target.accept(this)
-        assignment.value = assignment.value.accept(this)
-        return assignment
-    }
-
-    fun visit(postIncrDecr: PostIncrDecr): Statement {
-        postIncrDecr.target = postIncrDecr.target.accept(this)
-        return postIncrDecr
-    }
-
-    fun visit(contStmt: Continue): Statement {
-        return contStmt
-    }
-
-    fun visit(breakStmt: Break): Statement {
-        return breakStmt
-    }
-
-    fun visit(forLoop: ForLoop): Statement {
-        when(val newloopvar = forLoop.loopVar?.accept(this)) {
-            is IdentifierReference -> forLoop.loopVar = newloopvar
-            null -> forLoop.loopVar = null
-            else -> throw FatalAstException("can't change class of loopvar")
-        }
-        forLoop.iterable = forLoop.iterable.accept(this)
-        forLoop.body = forLoop.body.accept(this) as AnonymousScope
-        return forLoop
-    }
-
-    fun visit(whileLoop: WhileLoop): Statement {
-        whileLoop.condition = whileLoop.condition.accept(this)
-        whileLoop.body = whileLoop.body.accept(this) as AnonymousScope
-        return whileLoop
-    }
-
-    fun visit(repeatLoop: RepeatLoop): Statement {
-        repeatLoop.untilCondition = repeatLoop.untilCondition.accept(this)
-        repeatLoop.body = repeatLoop.body.accept(this) as AnonymousScope
-        return repeatLoop
-    }
-
-    fun visit(returnStmt: Return): Statement {
-        returnStmt.value = returnStmt.value?.accept(this)
-        return returnStmt
-    }
-
-    fun visit(arrayIndexedExpression: ArrayIndexedExpression): ArrayIndexedExpression {
-        val ident = arrayIndexedExpression.identifier.accept(this)
-        if(ident is IdentifierReference)
-            arrayIndexedExpression.identifier = ident
-        arrayIndexedExpression.arrayspec.accept(this)
-        return arrayIndexedExpression
-    }
-
-    fun visit(assignTarget: AssignTarget): AssignTarget {
-        when (val ident = assignTarget.identifier?.accept(this)) {
-            is IdentifierReference -> assignTarget.identifier = ident
-            null -> assignTarget.identifier = null
-            else -> throw FatalAstException("can't change class of assign target identifier")
-        }
-        assignTarget.arrayindexed = assignTarget.arrayindexed?.accept(this)
-        assignTarget.memoryAddress?.let { visit(it) }
-        return assignTarget
-    }
-
-    fun visit(scope: AnonymousScope): Statement {
-        scope.statements = scope.statements.map { it.accept(this) }.toMutableList()
-        return scope
-    }
-
-    fun visit(typecast: TypecastExpression): Expression {
-        typecast.expression = typecast.expression.accept(this)
-        return typecast
-    }
-
-    fun visit(memread: DirectMemoryRead): Expression {
-        memread.addressExpression = memread.addressExpression.accept(this)
-        return memread
-    }
-
-    fun visit(memwrite: DirectMemoryWrite) {
-        memwrite.addressExpression = memwrite.addressExpression.accept(this)
-    }
-
-    fun visit(addressOf: AddressOf): Expression {
-        val ident = addressOf.identifier.accept(this)
-        if(ident is IdentifierReference)
-            addressOf.identifier = ident
-        else
-            throw FatalAstException("can't change class of addressof identifier")
-        return addressOf
-    }
-
-    fun visit(inlineAssembly: InlineAssembly): Statement {
-        return inlineAssembly
-    }
-
-    fun visit(registerExpr: RegisterExpr): Expression {
-        return registerExpr
-    }
-
-    fun visit(builtinFunctionStatementPlaceholder: BuiltinFunctionStatementPlaceholder): Statement {
-        return builtinFunctionStatementPlaceholder
-    }
-
-    fun visit(nopStatement: NopStatement): Statement {
-        return nopStatement
-    }
-
-    fun visit(whenStatement: WhenStatement): Statement {
-        whenStatement.condition = whenStatement.condition.accept(this)
-        whenStatement.choices.forEach { it.accept(this) }
-        return whenStatement
-    }
-
-    fun visit(whenChoice: WhenChoice) {
-        whenChoice.values = whenChoice.values?.map { it.accept(this) }
-        val stmt = whenChoice.statements.accept(this)
-        if(stmt is AnonymousScope)
-            whenChoice.statements = stmt
-        else {
-            whenChoice.statements = AnonymousScope(mutableListOf(stmt), stmt.position)
-            whenChoice.statements.linkParents(whenChoice)
-        }
-    }
-
-    fun visit(structDecl: StructDecl): Statement {
-        structDecl.statements = structDecl.statements.map{ it.accept(this) }.toMutableList()
-        return structDecl
-    }
-
-    fun visit(structLv: StructLiteralValue): Expression {
-        structLv.values = structLv.values.map { it.accept(this) }
-        return structLv
-    }
-}

compiler/src/prog8/ast/processing/IAstVisitor.kt

@@ -7,7 +7,7 @@ import prog8.ast.statements.*
 
 interface IAstVisitor {
     fun visit(program: Program) {
-        program.modules.forEach { visit(it) }
+        program.modules.forEach { it.accept(this) }
     }
 
     fun visit(module: Module) {
@@ -33,6 +33,7 @@ interface IAstVisitor {
     fun visit(decl: VarDecl) {
         decl.value?.accept(this)
         decl.arraysize?.accept(this)
+        decl.struct?.accept(this)
     }
 
     fun visit(subroutine: Subroutine) {
@@ -95,14 +96,11 @@ interface IAstVisitor {
         postIncrDecr.target.accept(this)
     }
 
-    fun visit(contStmt: Continue) {
-    }
-
     fun visit(breakStmt: Break) {
     }
 
     fun visit(forLoop: ForLoop) {
-        forLoop.loopVar?.accept(this)
+        forLoop.loopVar.accept(this)
         forLoop.iterable.accept(this)
         forLoop.body.accept(this)
     }
@@ -113,17 +111,22 @@ interface IAstVisitor {
     }
 
     fun visit(repeatLoop: RepeatLoop) {
-        repeatLoop.untilCondition.accept(this)
+        repeatLoop.iterations?.accept(this)
         repeatLoop.body.accept(this)
     }
 
+    fun visit(untilLoop: UntilLoop) {
+        untilLoop.condition.accept(this)
+        untilLoop.body.accept(this)
+    }
+
     fun visit(returnStmt: Return) {
         returnStmt.value?.accept(this)
     }
 
     fun visit(arrayIndexedExpression: ArrayIndexedExpression) {
-        arrayIndexedExpression.identifier.accept(this)
-        arrayIndexedExpression.arrayspec.accept(this)
+        arrayIndexedExpression.arrayvar.accept(this)
+        arrayIndexedExpression.indexer.accept(this)
     }
 
     fun visit(assignTarget: AssignTarget) {
@@ -155,9 +158,6 @@ interface IAstVisitor {
     fun visit(inlineAssembly: InlineAssembly) {
     }
 
-    fun visit(registerExpr: RegisterExpr) {
-    }
-
     fun visit(builtinFunctionStatementPlaceholder: BuiltinFunctionStatementPlaceholder) {
     }
 
@@ -177,8 +177,4 @@ interface IAstVisitor {
     fun visit(structDecl: StructDecl) {
         structDecl.statements.forEach { it.accept(this) }
     }
-
-    fun visit(structLv: StructLiteralValue) {
-        structLv.values.forEach { it.accept(this) }
-    }
 }

compiler/src/prog8/ast/processing/ImportedModuleDirectiveRemover.kt

@@ -1,36 +1,22 @@
 package prog8.ast.processing
 
-import prog8.ast.Module
-import prog8.ast.base.SyntaxError
-import prog8.ast.base.printWarning
+import prog8.ast.INameScope
+import prog8.ast.Node
 import prog8.ast.statements.Directive
-import prog8.ast.statements.Statement
 
-internal class ImportedModuleDirectiveRemover : IAstModifyingVisitor {
-    private val checkResult: MutableList<SyntaxError> = mutableListOf()
-
-    internal fun result(): List<SyntaxError> {
-        return checkResult
-    }
 
+internal class ImportedModuleDirectiveRemover: AstWalker() {
     /**
      * Most global directives don't apply for imported modules, so remove them
      */
-    override fun visit(module: Module) {
-        super.visit(module)
-        val newStatements : MutableList<Statement> = mutableListOf()
 
-        val moduleLevelDirectives = listOf("%output", "%launcher", "%zeropage", "%zpreserved", "%address")
-        for (sourceStmt in module.statements) {
-            val stmt = sourceStmt.accept(this)
-            if(stmt is Directive && stmt.parent is Module) {
-                if(stmt.directive in moduleLevelDirectives) {
-                    printWarning("ignoring module directive because it was imported", stmt.position, stmt.directive)
-                    continue
-                }
-            }
-            newStatements.add(stmt)
+    private val moduleLevelDirectives = listOf("%output", "%launcher", "%zeropage", "%zpreserved", "%address")
+    private val noModifications = emptyList<IAstModification>()
+
+    override fun before(directive: Directive, parent: Node): Iterable<IAstModification> {
+        if(directive.directive in moduleLevelDirectives) {
+            return listOf(IAstModification.Remove(directive, parent as INameScope))
         }
-        module.statements = newStatements
+        return noModifications
     }
 }

compiler/src/prog8/ast/processing/LiteralsToAutoVars.kt

@@ -0,0 +1,53 @@
+package prog8.ast.processing
+
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.statements.*
+
+
+internal class LiteralsToAutoVars(private val program: Program) : AstWalker() {
+    private val noModifications = emptyList<IAstModification>()
+
+    override fun after(string: StringLiteralValue, parent: Node): Iterable<IAstModification> {
+        if(string.parent !is VarDecl && string.parent !is WhenChoice) {
+            // replace the literal string by a identifier reference to a new local vardecl
+            val vardecl = VarDecl.createAuto(string)
+            val identifier = IdentifierReference(listOf(vardecl.name), vardecl.position)
+            return listOf(
+                    IAstModification.ReplaceNode(string, identifier, parent),
+                    IAstModification.InsertFirst(vardecl, string.definingScope())
+            )
+        }
+        return noModifications
+    }
+
+    override fun after(array: ArrayLiteralValue, parent: Node): Iterable<IAstModification> {
+        val vardecl = array.parent as? VarDecl
+        if(vardecl!=null) {
+            // adjust the datatype of the array (to an educated guess)
+            val arrayDt = array.type
+            if(!arrayDt.istype(vardecl.datatype)) {
+                val cast = array.cast(vardecl.datatype)
+                if (cast != null && cast !== array)
+                    return listOf(IAstModification.ReplaceNode(vardecl.value!!, cast, vardecl))
+            }
+        } else {
+            val arrayDt = array.guessDatatype(program)
+            if(arrayDt.isKnown) {
+                // this array literal is part of an expression, turn it into an identifier reference
+                val litval2 = array.cast(arrayDt.typeOrElse(DataType.STRUCT))
+                if(litval2!=null) {
+                    val vardecl2 = VarDecl.createAuto(litval2)
+                    val identifier = IdentifierReference(listOf(vardecl2.name), vardecl2.position)
+                    return listOf(
+                            IAstModification.ReplaceNode(array, identifier, parent),
+                            IAstModification.InsertFirst(vardecl2, array.definingScope())
+                    )
+                }
+            }
+        }
+        return noModifications
+    }
+}

compiler/src/prog8/ast/processing/ReflectionAstWalker.kt

@@ -0,0 +1,71 @@
+package prog8.ast.processing
+
+
+/*
+This is here for reference only, reflection based ast walking is very slow
+when compared to the more verbose visitor pattern interfaces.
+Too bad, because the code is very small
+*/
+
+
+//import prog8.ast.NoAstWalk
+//import prog8.ast.Node
+//import prog8.ast.Program
+//import prog8.ast.base.Position
+//import prog8.ast.expressions.BinaryExpression
+//import prog8.ast.expressions.NumericLiteralValue
+//import kotlin.reflect.KClass
+//import kotlin.reflect.KVisibility
+//import kotlin.reflect.full.declaredMemberProperties
+//import kotlin.reflect.full.isSubtypeOf
+//import kotlin.reflect.full.starProjectedType
+//
+//
+//class ReflectionAstWalker {
+//    private val nodeType = Node::class.starProjectedType
+//    private val collectionType = Collection::class.starProjectedType
+//
+//
+//    fun walk(node: Node, nesting: Int) {
+//        val nodetype: KClass<out Node> = node::class
+//        val indent = "  ".repeat(nesting)
+//        //println("$indent VISITING ${nodetype.simpleName}")
+//        val visibleAstMembers = nodetype.declaredMemberProperties.filter {
+//            it.visibility!=KVisibility.PRIVATE && !it.isLateinit &&
+//                    !(it.annotations.any{a->a is NoAstWalk})
+//        }
+//        for(prop in visibleAstMembers) {
+//            if(prop.returnType.isSubtypeOf(nodeType)) {
+//                // println("$indent +PROP: ${prop.name}")
+//                walk(prop.call(node) as Node, nesting + 1)
+//            }
+//            else if(prop.returnType.isSubtypeOf(collectionType)) {
+//                val elementType = prop.returnType.arguments.single().type
+//                if(elementType!=null && elementType.isSubtypeOf(nodeType)) {
+//                    val nodes = prop.call(node) as Collection<Node>
+//                    nodes.forEach { walk(it, nesting+1) }
+//                }
+//            }
+//        }
+//    }
+//    fun walk(program: Program) {
+//        for(module in program.modules) {
+//            println("---MODULE $module---")
+//            walk(module, 0)
+//        }
+//    }
+//}
+//
+//
+//fun main() {
+//    val ast = BinaryExpression(
+//            NumericLiteralValue.optimalInteger(100, Position.DUMMY),
+//            "+",
+//            NumericLiteralValue.optimalInteger(200, Position.DUMMY),
+//            Position.DUMMY
+//    )
+//
+//    val walker = ReflectionAstWalker()
+//    walker.walk(ast,0)
+//
+//}

compiler/src/prog8/ast/processing/StatementReorderer.kt

@@ -1,258 +1,364 @@
 package prog8.ast.processing
 
 import prog8.ast.*
-import prog8.ast.base.DataType
-import prog8.ast.base.FatalAstException
-import prog8.ast.base.initvarsSubName
+import prog8.ast.base.*
 import prog8.ast.expressions.*
 import prog8.ast.statements.*
 
 
-private fun flattenStructAssignmentFromIdentifier(structAssignment: Assignment, program: Program): List<Assignment> {
-    val identifier = structAssignment.target.identifier!!
-    val identifierName = identifier.nameInSource.single()
-    val targetVar = identifier.targetVarDecl(program.namespace)!!
-    val struct = targetVar.struct!!
-    when (structAssignment.value) {
-        is IdentifierReference -> {
-            val sourceVar = (structAssignment.value as IdentifierReference).targetVarDecl(program.namespace)!!
-            if (sourceVar.struct == null)
-                throw FatalAstException("can only assign arrays or structs to structs")
-            // struct memberwise copy
-            val sourceStruct = sourceVar.struct!!
-            if(sourceStruct!==targetVar.struct) {
-                // structs are not the same in assignment
-                return listOf()     // error will be printed elsewhere
-            }
-            return struct.statements.zip(sourceStruct.statements).map { member ->
-                val targetDecl = member.first as VarDecl
-                val sourceDecl = member.second as VarDecl
-                if(targetDecl.name != sourceDecl.name)
-                    throw FatalAstException("struct member mismatch")
-                val mangled = mangledStructMemberName(identifierName, targetDecl.name)
-                val idref = IdentifierReference(listOf(mangled), structAssignment.position)
-                val sourcemangled = mangledStructMemberName(sourceVar.name, sourceDecl.name)
-                val sourceIdref = IdentifierReference(listOf(sourcemangled), structAssignment.position)
-                val assign = Assignment(AssignTarget(null, idref, null, null, structAssignment.position),
-                        null, sourceIdref, member.second.position)
-                assign.linkParents(structAssignment)
-                assign
-            }
-        }
-        is StructLiteralValue -> {
-            throw IllegalArgumentException("not going to flatten a structLv assignment here")
-        }
-        else -> throw FatalAstException("strange struct value")
-    }
-}
-
-
-internal class StatementReorderer(private val program: Program): IAstModifyingVisitor {
+internal class StatementReorderer(val program: Program, val errors: ErrorReporter) : AstWalker() {
     // Reorders the statements in a way the compiler needs.
     // - 'main' block must be the very first statement UNLESS it has an address set.
-    // - blocks are ordered by address, where blocks without address are put at the end.
-    // - in every scope:
-    //      -- the directives '%output', '%launcher', '%zeropage', '%zpreserved', '%address' and '%option' will come first.
-    //      -- all vardecls then follow.
-    //      -- the remaining statements then follow in their original order.
-    //
-    // - the 'start' subroutine in the 'main' block will be moved to the top immediately following the directives.
-    // - all other subroutines will be moved to the end of their block.
+    // - library blocks are put last.
+    // - blocks are ordered by address, where blocks without address are placed last.
+    // - in every block and module, most directives and vardecls are moved to the top. (not in subroutines!)
+    // - the 'start' subroutine is moved to the top.
+    // - (syntax desugaring) a vardecl with a non-const initializer value is split into a regular vardecl and an assignment statement.
+    // - (syntax desugaring) struct value assignment is expanded into several struct member assignments.
+    // - in-place assignments are reordered a bit so that they are mostly of the form A = A <operator> <rest>
     // - sorts the choices in when statement.
+    // - insert AddressOf (&) expression where required (string params to a UWORD function param etc).
 
+    private val noModifications = emptyList<IAstModification>()
     private val directivesToMove = setOf("%output", "%launcher", "%zeropage", "%zpreserved", "%address", "%option")
 
-    private val addReturns = mutableListOf<Pair<INameScope, Int>>()
-
-    override fun visit(module: Module) {
-        addReturns.clear()
-        super.visit(module)
-
+    override fun after(module: Module, parent: Node): Iterable<IAstModification> {
         val (blocks, other) = module.statements.partition { it is Block }
         module.statements = other.asSequence().plus(blocks.sortedBy { (it as Block).address ?: Int.MAX_VALUE }).toMutableList()
 
-        // make sure user-defined blocks come BEFORE library blocks, and move the "main" block to the top of everything
-        val nonLibraryBlocks = module.statements.withIndex()
-                .filter { it.value is Block && !(it.value as Block).isInLibrary }
-                .map { it.index to it.value }
-                .reversed()
-        for(nonLibBlock in nonLibraryBlocks)
-            module.statements.removeAt(nonLibBlock.first)
-        for(nonLibBlock in nonLibraryBlocks)
-            module.statements.add(0, nonLibBlock.second)
-        val mainBlock = module.statements.singleOrNull { it is Block && it.name=="main" }
-        if(mainBlock!=null && (mainBlock as Block).address==null) {
-            module.remove(mainBlock)
+        val mainBlock = module.statements.filterIsInstance<Block>().firstOrNull { it.name=="main" }
+        if(mainBlock!=null && mainBlock.address==null) {
+            module.statements.remove(mainBlock)
             module.statements.add(0, mainBlock)
         }
 
-        val varDecls = module.statements.filterIsInstance<VarDecl>()
-        module.statements.removeAll(varDecls)
-        module.statements.addAll(0, varDecls)
+        reorderVardeclsAndDirectives(module.statements)
+        return noModifications
+    }
 
-        val directives = module.statements.filter {it is Directive && it.directive in directivesToMove}
-        module.statements.removeAll(directives)
-        module.statements.addAll(0, directives)
+    private fun reorderVardeclsAndDirectives(statements: MutableList<Statement>) {
+        val varDecls = statements.filterIsInstance<VarDecl>()
+        statements.removeAll(varDecls)
+        statements.addAll(0, varDecls)
 
-        for(pos in addReturns) {
-            println(pos)
-            val returnStmt = Return(null, pos.first.position)
-            returnStmt.linkParents(pos.first as Node)
-            pos.first.statements.add(pos.second, returnStmt)
+        val directives = statements.filterIsInstance<Directive>().filter {it.directive in directivesToMove}
+        statements.removeAll(directives)
+        statements.addAll(0, directives)
+    }
+
+    override fun before(block: Block, parent: Node): Iterable<IAstModification> {
+        parent as Module
+        if(block.isInLibrary) {
+            return listOf(
+                    IAstModification.Remove(block, parent),
+                    IAstModification.InsertLast(block, parent)
+            )
+        }
+
+        reorderVardeclsAndDirectives(block.statements)
+        return noModifications
+    }
+
+    override fun before(subroutine: Subroutine, parent: Node): Iterable<IAstModification> {
+        if(subroutine.name=="start" && parent is Block) {
+            if(parent.statements.filterIsInstance<Subroutine>().first().name!="start") {
+                return listOf(
+                        IAstModification.Remove(subroutine, parent),
+                        IAstModification.InsertFirst(subroutine, parent)
+                )
+            }
+        }
+        return noModifications
+    }
+
+    override fun after(arrayIndexedExpression: ArrayIndexedExpression, parent: Node): Iterable<IAstModification> {
+        when (val expr2 = arrayIndexedExpression.indexer.origExpression) {
+            is NumericLiteralValue -> {
+                arrayIndexedExpression.indexer.indexNum = expr2
+                arrayIndexedExpression.indexer.origExpression = null
+                return noModifications
+            }
+            is IdentifierReference -> {
+                arrayIndexedExpression.indexer.indexVar = expr2
+                arrayIndexedExpression.indexer.origExpression = null
+                return noModifications
+            }
+            is Expression -> {
+                // replace complex indexing with a temp variable
+                return getAutoIndexerVarFor(arrayIndexedExpression)
+            }
+            else -> return noModifications
         }
     }
 
-    override fun visit(block: Block): Statement {
+    private fun getAutoIndexerVarFor(expr: ArrayIndexedExpression): MutableList<IAstModification> {
+        val modifications = mutableListOf<IAstModification>()
+        val subroutine = expr.definingSubroutine()!!
+        val statement = expr.containingStatement()
+        val indexerVarPrefix = "prog8_autovar_index_"
+        val repo = subroutine.asmGenInfo.usedAutoArrayIndexerForStatements
 
-        val subroutines = block.statements.filterIsInstance<Subroutine>()
-        var numSubroutinesAtEnd = 0
-        // move all subroutines to the end of the block
-        for (subroutine in subroutines) {
-            if(subroutine.name!="start" || block.name!="main") {
-                block.remove(subroutine)
-                block.statements.add(subroutine)
-            }
-            numSubroutinesAtEnd++
-        }
-        // move the "start" subroutine to the top
-        if(block.name=="main") {
-            block.statements.singleOrNull { it is Subroutine && it.name == "start" } ?.let {
-                block.remove(it)
-                block.statements.add(0, it)
-                numSubroutinesAtEnd--
-            }
+        // TODO make this even smarter so that an indexerVar can be reused for a different following statement...  requires updating the partOfStatement?
+        var indexerVar = repo.firstOrNull { it.replaces isSameAs expr.indexer }
+        if(indexerVar==null) {
+            // add another loop index var to be used for this expression
+            val indexerVarName = "$indexerVarPrefix${expr.indexer.hashCode()}"
+            indexerVar = AsmGenInfo.ArrayIndexerInfo(indexerVarName, expr.indexer, statement)
+            repo.add(indexerVar)
+            // create the indexer var at block level scope
+            val vardecl = VarDecl(VarDeclType.VAR, DataType.UBYTE, ZeropageWish.PREFER_ZEROPAGE,
+                    null, indexerVarName, null, null, isArray = false, autogeneratedDontRemove = true, position = expr.position)
+            modifications.add(IAstModification.InsertFirst(vardecl, subroutine))
         }
+        indexerVar.used++       // keep track of how many times it it used, to avoid assigning it multiple times
 
-        // make sure there is a 'return' in front of the first subroutine
-        // (if it isn't the first statement in the block itself, and isn't the program's entrypoint)
-        if(numSubroutinesAtEnd>0 && block.statements.size > (numSubroutinesAtEnd+1)) {
-            val firstSub = block.statements[block.statements.size - numSubroutinesAtEnd] as Subroutine
-            if(firstSub.name != "start" && block.name != "main") {
-                val stmtBeforeFirstSub = block.statements[block.statements.size - numSubroutinesAtEnd - 1]
-                if (stmtBeforeFirstSub !is Return
-                        && stmtBeforeFirstSub !is Jump
-                        && stmtBeforeFirstSub !is Subroutine
-                        && stmtBeforeFirstSub !is BuiltinFunctionStatementPlaceholder) {
-                    val ret = Return(null, stmtBeforeFirstSub.position)
-                    ret.linkParents(block)
-                    block.statements.add(block.statements.size - numSubroutinesAtEnd, ret)
+        // replace the indexer with just the variable
+        // assign the indexing expression to the helper variable, but only if that hasn't been done already
+        val indexerExpression = expr.indexer.origExpression!!
+        val target = AssignTarget(IdentifierReference(listOf(indexerVar.name), indexerExpression.position), null, null, indexerExpression.position)
+        if(indexerVar.used==1) {
+            val assign = Assignment(target, indexerExpression, indexerExpression.position)
+            modifications.add(IAstModification.InsertBefore(statement, assign, statement.definingScope()))
+        }
+        modifications.add(IAstModification.SetExpression( {
+            expr.indexer.indexVar = it as IdentifierReference
+            expr.indexer.indexNum = null
+            expr.indexer.origExpression = null
+        }, target.identifier!!.copy(), expr.indexer))
+
+        return modifications
+    }
+
+    override fun after(whenStatement: WhenStatement, parent: Node): Iterable<IAstModification> {
+        val choices = whenStatement.choiceValues(program).sortedBy {
+            it.first?.first() ?: Int.MAX_VALUE
+        }
+        whenStatement.choices.clear()
+        choices.mapTo(whenStatement.choices) { it.second }
+        return noModifications
+    }
+
+    override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
+        val declValue = decl.value
+        if(declValue!=null && decl.type== VarDeclType.VAR && decl.datatype in NumericDatatypes) {
+            val declConstValue = declValue.constValue(program)
+            if(declConstValue==null) {
+                // move the vardecl (without value) to the scope and replace this with a regular assignment
+                // Unless we're dealing with a floating point variable because that will actually make things less efficient at the moment (because floats are mostly calcualated via the stack)
+                if(decl.datatype!=DataType.FLOAT) {
+                    decl.value = null
+                    decl.allowInitializeWithZero = false
+                    val target = AssignTarget(IdentifierReference(listOf(decl.name), decl.position), null, null, decl.position)
+                    val assign = Assignment(target, declValue, decl.position)
+                    return listOf(
+                            IAstModification.ReplaceNode(decl, assign, parent),
+                            IAstModification.InsertFirst(decl, decl.definingScope())
+                    )
                 }
             }
         }
-
-        val varDecls = block.statements.filterIsInstance<VarDecl>()
-        block.statements.removeAll(varDecls)
-        block.statements.addAll(0, varDecls)
-        val directives = block.statements.filter {it is Directive && it.directive in directivesToMove}
-        block.statements.removeAll(directives)
-        block.statements.addAll(0, directives)
-        block.linkParents(block.parent)
-
-        // create subroutine that initializes the block's variables (if any)
-        val varInits = block.statements.withIndex().filter { it.value is VariableInitializationAssignment }
-        if(varInits.isNotEmpty()) {
-            val statements = varInits.map{it.value}.toMutableList()
-            val varInitSub = Subroutine(initvarsSubName, emptyList(), emptyList(), emptyList(), emptyList(),
-                    emptySet(), null, false, statements, block.position)
-            varInitSub.keepAlways = true
-            varInitSub.linkParents(block)
-            block.statements.add(varInitSub)
-
-            // remove the varinits from the block's statements
-            for(index in varInits.map{it.index}.reversed())
-                block.statements.removeAt(index)
-        }
-
-        return super.visit(block)
+        return noModifications
     }
 
-    override fun visit(subroutine: Subroutine): Statement {
-        super.visit(subroutine)
+    override fun before(assignment: Assignment, parent: Node): Iterable<IAstModification> {
+        val valueType = assignment.value.inferType(program)
+        val targetType = assignment.target.inferType(program)
+        var assignments = emptyList<Assignment>()
 
-        val scope = subroutine.definingScope()
-        if(scope is Subroutine) {
-            for(stmt in scope.statements.withIndex()) {
-                if(stmt.index>0 && stmt.value===subroutine) {
-                    val precedingStmt = scope.statements[stmt.index-1]
-                    if(precedingStmt !is Jump && precedingStmt !is Subroutine) {
-                        // insert a return statement before a nested subroutine, to avoid falling trough inside the subroutine
-                        addReturns.add(Pair(scope, stmt.index))
+        if(targetType.istype(DataType.STRUCT) && (valueType.istype(DataType.STRUCT) || valueType.typeOrElse(DataType.STRUCT) in ArrayDatatypes )) {
+            assignments = if (assignment.value is ArrayLiteralValue) {
+                flattenStructAssignmentFromStructLiteral(assignment)    //  'structvar = [ ..... ] '
+            } else {
+                flattenStructAssignmentFromIdentifier(assignment)    //   'structvar1 = structvar2'
+            }
+        }
+
+        if(targetType.typeOrElse(DataType.STRUCT) in ArrayDatatypes && valueType.typeOrElse(DataType.STRUCT) in ArrayDatatypes ) {
+            assignments = if (assignment.value is ArrayLiteralValue) {
+                flattenArrayAssignmentFromArrayLiteral(assignment)    //  'arrayvar = [ ..... ] '
+            } else {
+                flattenArrayAssignmentFromIdentifier(assignment)    //   'arrayvar1 = arrayvar2'
+            }
+        }
+
+        if(assignments.isNotEmpty()) {
+            val modifications = mutableListOf<IAstModification>()
+            val scope = assignment.definingScope()
+            assignments.reversed().mapTo(modifications) { IAstModification.InsertAfter(assignment, it, scope) }
+            modifications.add(IAstModification.Remove(assignment, scope))
+            return modifications
+        }
+
+        return noModifications
+    }
+
+    override fun after(assignment: Assignment, parent: Node): Iterable<IAstModification> {
+        // rewrite in-place assignment expressions a bit so that the assignment target usually is the leftmost operand
+        val binExpr = assignment.value as? BinaryExpression
+        if(binExpr!=null) {
+            if(binExpr.left isSameAs assignment.target) {
+                // A = A <operator> 5, unchanged
+                return noModifications
+            }
+
+            if(binExpr.operator in associativeOperators) {
+                if (binExpr.right isSameAs assignment.target) {
+                    // A = v <associative-operator> A  ==>  A = A <associative-operator> v
+                    return listOf(IAstModification.SwapOperands(binExpr))
+                }
+
+                val leftBinExpr = binExpr.left as? BinaryExpression
+                if(leftBinExpr?.operator == binExpr.operator) {
+                    return if(leftBinExpr.left isSameAs assignment.target) {
+                        // A = (A <associative-operator> x) <same-operator> y ==> A = A <associative-operator> (x <same-operator> y)
+                        val newRight = BinaryExpression(leftBinExpr.right, binExpr.operator, binExpr.right, binExpr.position)
+                        val newValue = BinaryExpression(leftBinExpr.left, binExpr.operator, newRight, binExpr.position)
+                        listOf(IAstModification.ReplaceNode(binExpr, newValue, assignment))
+                    } else {
+                        // A = (x <associative-operator> A) <same-operator> y ==> A = A <associative-operator> (x <same-operator> y)
+                        val newRight = BinaryExpression(leftBinExpr.left, binExpr.operator, binExpr.right, binExpr.position)
+                        val newValue = BinaryExpression(leftBinExpr.right, binExpr.operator, newRight, binExpr.position)
+                        listOf(IAstModification.ReplaceNode(binExpr, newValue, assignment))
+                    }
+                }
+                val rightBinExpr = binExpr.right as? BinaryExpression
+                if(rightBinExpr?.operator == binExpr.operator) {
+                    return if(rightBinExpr.left isSameAs assignment.target) {
+                        // A = x <associative-operator> (A <same-operator> y) ==> A = A <associative-operator> (x <same-operator> y)
+                        val newRight = BinaryExpression(binExpr.left, binExpr.operator, rightBinExpr.right, binExpr.position)
+                        val newValue = BinaryExpression(rightBinExpr.left, binExpr.operator, newRight, binExpr.position)
+                        listOf(IAstModification.ReplaceNode(binExpr, newValue, assignment))
+                    } else {
+                        // A = x <associative-operator> (y <same-operator> A) ==> A = A <associative-operator> (x <same-operator> y)
+                        val newRight = BinaryExpression(binExpr.left, binExpr.operator, rightBinExpr.left, binExpr.position)
+                        val newValue = BinaryExpression(rightBinExpr.right, binExpr.operator, newRight, binExpr.position)
+                        listOf(IAstModification.ReplaceNode(binExpr, newValue, assignment))
                     }
                 }
             }
         }
 
-        val varDecls = subroutine.statements.filterIsInstance<VarDecl>()
-        subroutine.statements.removeAll(varDecls)
-        subroutine.statements.addAll(0, varDecls)
-        val directives = subroutine.statements.filter {it is Directive && it.directive in directivesToMove}
-        subroutine.statements.removeAll(directives)
-        subroutine.statements.addAll(0, directives)
-
-        if(subroutine.returntypes.isEmpty()) {
-            // add the implicit return statement at the end (if it's not there yet), but only if it's not a kernel routine.
-            // and if an assembly block doesn't contain a rts/rti
-            if(subroutine.asmAddress==null && subroutine.amountOfRtsInAsm()==0) {
-                if (subroutine.statements.lastOrNull {it !is VarDecl } !is Return) {
-                    val returnStmt = Return(null, subroutine.position)
-                    returnStmt.linkParents(subroutine)
-                    subroutine.statements.add(returnStmt)
-                }
-            }
-        }
-
-        return subroutine
+        return noModifications
     }
 
-    override fun visit(assignment: Assignment): Statement {
-        val assg = super.visit(assignment)
-        if(assg !is Assignment)
-            return assg
+    private fun flattenArrayAssignmentFromArrayLiteral(assign: Assignment): List<Assignment> {
+        val identifier = assign.target.identifier!!
+        val targetVar = identifier.targetVarDecl(program.namespace)!!
+        val alv = assign.value as? ArrayLiteralValue
+        return flattenArrayAssign(targetVar, alv, identifier, assign.position)
+    }
 
-        // see if a typecast is needed to convert the value's type into the proper target type
-        val valueItype = assg.value.inferType(program)
-        val targetItype = assg.target.inferType(program, assg)
+    private fun flattenArrayAssignmentFromIdentifier(assign: Assignment): List<Assignment> {
+        val identifier = assign.target.identifier!!
+        val targetVar = identifier.targetVarDecl(program.namespace)!!
+        val sourceIdent = assign.value as IdentifierReference
+        val sourceVar = sourceIdent.targetVarDecl(program.namespace)!!
+        if(!sourceVar.isArray) {
+            errors.err("value must be an array",  sourceIdent.position)
+            return emptyList()
+        }
+        val alv = sourceVar.value as? ArrayLiteralValue
+        return flattenArrayAssign(targetVar, alv, identifier, assign.position)
+    }
 
-        if(targetItype.isKnown && valueItype.isKnown) {
-            val targettype = targetItype.typeOrElse(DataType.STRUCT)
-            val valuetype = valueItype.typeOrElse(DataType.STRUCT)
-
-            // struct assignments will be flattened (if it's not a struct literal)
-            if (valuetype == DataType.STRUCT && targettype == DataType.STRUCT) {
-                if (assg.value is StructLiteralValue)
-                    return assg  // do NOT flatten it at this point!! (the compiler will take care if it, later, if needed)
-
-                val assignments = flattenStructAssignmentFromIdentifier(assg, program)    //   'structvar1 = structvar2'
-                return if (assignments.isEmpty()) {
-                    // something went wrong (probably incompatible struct types)
-                    // we'll get an error later from the AstChecker
-                    assg
-                } else {
-                    val scope = AnonymousScope(assignments.toMutableList(), assg.position)
-                    scope.linkParents(assg.parent)
-                    scope
-                }
-            }
+    private fun flattenArrayAssign(targetVar: VarDecl, alv: ArrayLiteralValue?, identifier: IdentifierReference, position: Position): List<Assignment> {
+        if(targetVar.arraysize==null) {
+            errors.err("array has no defined size", identifier.position)
+            return emptyList()
         }
 
-        if(assg.aug_op!=null) {
-            // transform augmented assg into normal assg so we have one case less to deal with later
-            val newTarget: Expression =
-                    when {
-                        assg.target.register != null -> RegisterExpr(assg.target.register!!, assg.target.position)
-                        assg.target.identifier != null -> assg.target.identifier!!
-                        assg.target.arrayindexed != null -> assg.target.arrayindexed!!
-                        assg.target.memoryAddress != null -> DirectMemoryRead(assg.target.memoryAddress!!.addressExpression, assg.value.position)
-                        else -> throw FatalAstException("strange assg")
+        if(alv==null || alv.value.size != targetVar.arraysize!!.constIndex()) {
+            errors.err("element count mismatch", position)
+            return emptyList()
+        }
+
+        // TODO use a pointer loop instead of individual assignments
+        return alv.value.mapIndexed { index, value ->
+            val idx = ArrayIndexedExpression(identifier, ArrayIndex(NumericLiteralValue(DataType.UBYTE, index, position), position), position)
+            Assignment(AssignTarget(null, idx, null, position), value, value.position)
+        }
+    }
+
+    private fun flattenStructAssignmentFromStructLiteral(structAssignment: Assignment): List<Assignment> {
+        val identifier = structAssignment.target.identifier!!
+        val identifierName = identifier.nameInSource.single()
+        val targetVar = identifier.targetVarDecl(program.namespace)!!
+        val struct = targetVar.struct!!
+
+        val slv = structAssignment.value as? ArrayLiteralValue
+        if(slv==null || slv.value.size != struct.numberOfElements) {
+            errors.err("element count mismatch", structAssignment.position)
+            return emptyList()
+        }
+
+        return struct.statements.zip(slv.value).map { (targetDecl, sourceValue) ->
+            targetDecl as VarDecl
+            val mangled = mangledStructMemberName(identifierName, targetDecl.name)
+            val idref = IdentifierReference(listOf(mangled), structAssignment.position)
+            val assign = Assignment(AssignTarget(idref, null, null, structAssignment.position),
+                    sourceValue, sourceValue.position)
+            assign.linkParents(structAssignment)
+            assign
+        }
+    }
+
+    private fun flattenStructAssignmentFromIdentifier(structAssignment: Assignment): List<Assignment> {
+        // TODO use memcopy beyond a certain number of elements
+        val identifier = structAssignment.target.identifier!!
+        val identifierName = identifier.nameInSource.single()
+        val targetVar = identifier.targetVarDecl(program.namespace)!!
+        val struct = targetVar.struct!!
+        when (structAssignment.value) {
+            is IdentifierReference -> {
+                val sourceVar = (structAssignment.value as IdentifierReference).targetVarDecl(program.namespace)!!
+                when {
+                    sourceVar.struct!=null -> {
+                        // struct memberwise copy
+                        val sourceStruct = sourceVar.struct!!
+                        if(sourceStruct!==targetVar.struct) {
+                            // structs are not the same in assignment
+                            return listOf()     // error will be printed elsewhere
+                        }
+                        if(struct.statements.size!=sourceStruct.statements.size)
+                            return listOf()     // error will be printed elsewhere
+                        return struct.statements.zip(sourceStruct.statements).map { member ->
+                            val targetDecl = member.first as VarDecl
+                            val sourceDecl = member.second as VarDecl
+                            if(targetDecl.name != sourceDecl.name)
+                                throw FatalAstException("struct member mismatch")
+                            val mangled = mangledStructMemberName(identifierName, targetDecl.name)
+                            val idref = IdentifierReference(listOf(mangled), structAssignment.position)
+                            val sourcemangled = mangledStructMemberName(sourceVar.name, sourceDecl.name)
+                            val sourceIdref = IdentifierReference(listOf(sourcemangled), structAssignment.position)
+                            val assign = Assignment(AssignTarget(idref, null, null, structAssignment.position), sourceIdref, member.second.position)
+                            assign.linkParents(structAssignment)
+                            assign
+                        }
                     }
-
-            val expression = BinaryExpression(newTarget, assg.aug_op.substringBeforeLast('='), assg.value, assg.position)
-            expression.linkParents(assg.parent)
-            val convertedAssignment = Assignment(assg.target, null, expression, assg.position)
-            convertedAssignment.linkParents(assg.parent)
-            return super.visit(convertedAssignment)
+                    sourceVar.isArray -> {
+                        val array = (sourceVar.value as ArrayLiteralValue).value
+                        if(struct.statements.size!=array.size)
+                            return listOf()     // error will be printed elsewhere
+                        return struct.statements.zip(array).map {
+                            val decl = it.first as VarDecl
+                            val mangled = mangledStructMemberName(identifierName, decl.name)
+                            val targetName = IdentifierReference(listOf(mangled), structAssignment.position)
+                            val target = AssignTarget(targetName, null, null, structAssignment.position)
+                            val assign = Assignment(target, it.second, structAssignment.position)
+                            assign.linkParents(structAssignment)
+                            assign
+                        }
+                    }
+                    else -> {
+                        throw FatalAstException("can only assign arrays or structs to structs")
+                    }
+                }
+            }
+            is ArrayLiteralValue -> {
+                throw IllegalArgumentException("not going to flatten a structLv assignment here")
+            }
+            else -> throw FatalAstException("strange struct value")
         }
-
-        return assg
     }
+
 }

compiler/src/prog8/ast/processing/TypecastsAdder.kt

@@ -2,113 +2,167 @@ package prog8.ast.processing
 
 import prog8.ast.IFunctionCall
 import prog8.ast.INameScope
+import prog8.ast.Node
 import prog8.ast.Program
-import prog8.ast.base.DataType
-import prog8.ast.base.FatalAstException
-import prog8.ast.base.printWarning
+import prog8.ast.base.*
 import prog8.ast.expressions.*
 import prog8.ast.statements.*
 import prog8.functions.BuiltinFunctions
 
 
-internal class TypecastsAdder(private val program: Program): IAstModifyingVisitor {
-    // Make sure any value assignments get the proper type casts if needed to cast them into the target variable's type.
-    // (this includes function call arguments)
+class TypecastsAdder(val program: Program, val errors: ErrorReporter) : AstWalker() {
+    /*
+     * Make sure any value assignments get the proper type casts if needed to cast them into the target variable's type.
+     * (this includes function call arguments)
+     */
 
-    override fun visit(expr: BinaryExpression): Expression {
-        val expr2 = super.visit(expr)
-        if(expr2 !is BinaryExpression)
-            return expr2
-        val leftDt = expr2.left.inferType(program)
-        val rightDt = expr2.right.inferType(program)
+    private val noModifications = emptyList<IAstModification>()
+
+    override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
+        val declValue = decl.value
+        if(decl.type==VarDeclType.VAR && declValue!=null && decl.struct==null) {
+            val valueDt = declValue.inferType(program)
+            if(!valueDt.istype(decl.datatype)) {
+
+                // don't add a typecast on an array initializer value
+                if(valueDt.typeOrElse(DataType.STRUCT) in IntegerDatatypes && decl.datatype in ArrayDatatypes)
+                    return noModifications
+
+                return listOf(IAstModification.ReplaceNode(
+                        declValue,
+                        TypecastExpression(declValue, decl.datatype, true, declValue.position),
+                        decl
+                ))
+            }
+        }
+        return noModifications
+    }
+
+    override fun after(expr: BinaryExpression, parent: Node): Iterable<IAstModification> {
+        val leftDt = expr.left.inferType(program)
+        val rightDt = expr.right.inferType(program)
         if(leftDt.isKnown && rightDt.isKnown && leftDt!=rightDt) {
             // determine common datatype and add typecast as required to make left and right equal types
-            val (commonDt, toFix) = BinaryExpression.commonDatatype(leftDt.typeOrElse(DataType.STRUCT), rightDt.typeOrElse(DataType.STRUCT), expr2.left, expr2.right)
+            val (commonDt, toFix) = BinaryExpression.commonDatatype(leftDt.typeOrElse(DataType.STRUCT), rightDt.typeOrElse(DataType.STRUCT), expr.left, expr.right)
             if(toFix!=null) {
-                when {
-                    toFix===expr2.left -> {
-                        expr2.left = TypecastExpression(expr2.left, commonDt, true, expr2.left.position)
-                        expr2.left.linkParents(expr2)
-                    }
-                    toFix===expr2.right -> {
-                        expr2.right = TypecastExpression(expr2.right, commonDt, true, expr2.right.position)
-                        expr2.right.linkParents(expr2)
-                    }
+                return when {
+                    toFix===expr.left -> listOf(IAstModification.ReplaceNode(
+                            expr.left, TypecastExpression(expr.left, commonDt, true, expr.left.position), expr))
+                    toFix===expr.right -> listOf(IAstModification.ReplaceNode(
+                            expr.right, TypecastExpression(expr.right, commonDt, true, expr.right.position), expr))
                     else -> throw FatalAstException("confused binary expression side")
                 }
             }
         }
-        return expr2
+        return noModifications
     }
 
-    override fun visit(assignment: Assignment): Statement {
-        val assg = super.visit(assignment)
-        if(assg !is Assignment)
-            return assg
-
+    override fun after(assignment: Assignment, parent: Node): Iterable<IAstModification> {
         // see if a typecast is needed to convert the value's type into the proper target type
-        val valueItype = assg.value.inferType(program)
-        val targetItype = assg.target.inferType(program, assg)
-
+        val valueItype = assignment.value.inferType(program)
+        val targetItype = assignment.target.inferType(program)
         if(targetItype.isKnown && valueItype.isKnown) {
             val targettype = targetItype.typeOrElse(DataType.STRUCT)
             val valuetype = valueItype.typeOrElse(DataType.STRUCT)
             if (valuetype != targettype) {
                 if (valuetype isAssignableTo targettype) {
-                    assg.value = TypecastExpression(assg.value, targettype, true, assg.value.position)
-                    assg.value.linkParents(assg)
+                    if(valuetype in IterableDatatypes && targettype==DataType.UWORD)
+                        // special case, don't typecast STR/arrays to UWORD, we support those assignments "directly"
+                        return noModifications
+                    return listOf(IAstModification.ReplaceNode(
+                            assignment.value,
+                            TypecastExpression(assignment.value, targettype, true, assignment.value.position),
+                            assignment))
+                } else {
+                    fun castLiteral(cvalue: NumericLiteralValue): List<IAstModification.ReplaceNode> {
+                        val cast = cvalue.cast(targettype)
+                        return if(cast.isValid)
+                            listOf(IAstModification.ReplaceNode(cvalue, cast.valueOrZero(), cvalue.parent))
+                        else
+                            emptyList()
+                    }
+                    val cvalue = assignment.value.constValue(program)
+                    if(cvalue!=null) {
+                        val number = cvalue.number.toDouble()
+                        // more complex comparisons if the type is different, but the constant value is compatible
+                        if (valuetype == DataType.BYTE && targettype == DataType.UBYTE) {
+                            if(number>0)
+                                return castLiteral(cvalue)
+                        } else if (valuetype == DataType.WORD && targettype == DataType.UWORD) {
+                            if(number>0)
+                                return castLiteral(cvalue)
+                        } else if (valuetype == DataType.UBYTE && targettype == DataType.BYTE) {
+                            if(number<0x80)
+                                return castLiteral(cvalue)
+                        } else if (valuetype == DataType.UWORD && targettype == DataType.WORD) {
+                            if(number<0x8000)
+                                return castLiteral(cvalue)
+                        }
+                    }
                 }
-                // if they're not assignable, we'll get a proper error later from the AstChecker
             }
         }
-        return assg
+        return noModifications
     }
 
-    override fun visit(functionCallStatement: FunctionCallStatement): Statement {
-        checkFunctionCallArguments(functionCallStatement, functionCallStatement.definingScope())
-        return super.visit(functionCallStatement)
+    override fun after(functionCallStatement: FunctionCallStatement, parent: Node): Iterable<IAstModification> {
+        return afterFunctionCallArgs(functionCallStatement, functionCallStatement.definingScope())
     }
 
-    override fun visit(functionCall: FunctionCall): Expression {
-        checkFunctionCallArguments(functionCall, functionCall.definingScope())
-        return super.visit(functionCall)
+    override fun after(functionCall: FunctionCall, parent: Node): Iterable<IAstModification> {
+        return afterFunctionCallArgs(functionCall, functionCall.definingScope())
     }
 
-    private fun checkFunctionCallArguments(call: IFunctionCall, scope: INameScope) {
+    private fun afterFunctionCallArgs(call: IFunctionCall, scope: INameScope): Iterable<IAstModification> {
         // see if a typecast is needed to convert the arguments into the required parameter's type
+        val modifications = mutableListOf<IAstModification>()
+
         when(val sub = call.target.targetStatement(scope)) {
             is Subroutine -> {
-                for(arg in sub.parameters.zip(call.args.withIndex())) {
-                    val argItype = arg.second.value.inferType(program)
+                sub.parameters.zip(call.args).forEachIndexed { index, pair ->
+                    val argItype = pair.second.inferType(program)
                     if(argItype.isKnown) {
                         val argtype = argItype.typeOrElse(DataType.STRUCT)
-                        val requiredType = arg.first.type
+                        val requiredType = pair.first.type
                         if (requiredType != argtype) {
                             if (argtype isAssignableTo requiredType) {
-                                val typecasted = TypecastExpression(arg.second.value, requiredType, true, arg.second.value.position)
-                                typecasted.linkParents(arg.second.value.parent)
-                                call.args[arg.second.index] = typecasted
+                                modifications += IAstModification.ReplaceNode(
+                                        call.args[index],
+                                        TypecastExpression(pair.second, requiredType, true, pair.second.position),
+                                        call as Node)
+                            } else if(requiredType == DataType.UWORD && argtype in PassByReferenceDatatypes) {
+                                // we allow STR/ARRAY values in place of UWORD parameters. Take their address instead.
+                                if(pair.second is IdentifierReference) {
+                                    modifications += IAstModification.ReplaceNode(
+                                            call.args[index],
+                                            AddressOf(pair.second as IdentifierReference, pair.second.position),
+                                            call as Node)
+                                }
+                            } else if(pair.second is NumericLiteralValue) {
+                                val cast = (pair.second as NumericLiteralValue).cast(requiredType)
+                                if(cast.isValid)
+                                    modifications += IAstModification.ReplaceNode(
+                                            call.args[index],
+                                            cast.valueOrZero(),
+                                            call as Node)
                             }
-                            // if they're not assignable, we'll get a proper error later from the AstChecker
                         }
                     }
                 }
             }
             is BuiltinFunctionStatementPlaceholder -> {
                 val func = BuiltinFunctions.getValue(sub.name)
-                if(func.pure) {
-                    // non-pure functions don't get automatic typecasts because sometimes they act directly on their parameters
-                    for (arg in func.parameters.zip(call.args.withIndex())) {
-                        val argItype = arg.second.value.inferType(program)
-                        if (argItype.isKnown) {
-                            val argtype = argItype.typeOrElse(DataType.STRUCT)
-                            if (arg.first.possibleDatatypes.any { argtype == it })
-                                continue
-                            for (possibleType in arg.first.possibleDatatypes) {
+                func.parameters.zip(call.args).forEachIndexed { index, pair ->
+                    val argItype = pair.second.inferType(program)
+                    if (argItype.isKnown) {
+                        val argtype = argItype.typeOrElse(DataType.STRUCT)
+                        if (pair.first.possibleDatatypes.all { argtype != it }) {
+                            for (possibleType in pair.first.possibleDatatypes) {
                                 if (argtype isAssignableTo possibleType) {
-                                    val typecasted = TypecastExpression(arg.second.value, possibleType, true, arg.second.value.position)
-                                    typecasted.linkParents(arg.second.value.parent)
-                                    call.args[arg.second.index] = typecasted
+                                    modifications += IAstModification.ReplaceNode(
+                                            call.args[index],
+                                            TypecastExpression(pair.second, possibleType, true, pair.second.position),
+                                            call as Node)
                                     break
                                 }
                             }
@@ -116,83 +170,63 @@ internal class TypecastsAdder(private val program: Program): IAstModifyingVisito
                     }
                 }
             }
-            null -> {}
-            else -> throw FatalAstException("call to something weird $sub   ${call.target}")
+            else -> { }
         }
+
+        return modifications
     }
 
-    override fun visit(typecast: TypecastExpression): Expression {
+    override fun after(typecast: TypecastExpression, parent: Node): Iterable<IAstModification> {
         // warn about any implicit type casts to Float, because that may not be intended
         if(typecast.implicit && typecast.type in setOf(DataType.FLOAT, DataType.ARRAY_F)) {
-            printWarning("byte or word value implicitly converted to float. Suggestion: use explicit cast as float, a float number, or revert to integer arithmetic", typecast.position)
+            errors.warn("integer implicitly converted to float. Suggestion: use float literals, add an explicit cast, or revert to integer arithmetic", typecast.position)
         }
-        return super.visit(typecast)
+        return noModifications
     }
 
-    override fun visit(memread: DirectMemoryRead): Expression {
+    override fun after(memread: DirectMemoryRead, parent: Node): Iterable<IAstModification> {
         // make sure the memory address is an uword
         val dt = memread.addressExpression.inferType(program)
         if(dt.isKnown && dt.typeOrElse(DataType.UWORD)!=DataType.UWORD) {
-            val literaladdr = memread.addressExpression as? NumericLiteralValue
-            if(literaladdr!=null) {
-                memread.addressExpression = literaladdr.cast(DataType.UWORD)
-            } else {
-                memread.addressExpression = TypecastExpression(memread.addressExpression, DataType.UWORD, true, memread.addressExpression.position)
-                memread.addressExpression.parent = memread
-            }
+            val typecast = (memread.addressExpression as? NumericLiteralValue)?.cast(DataType.UWORD)?.valueOrZero()
+                    ?: TypecastExpression(memread.addressExpression, DataType.UWORD, true, memread.addressExpression.position)
+            return listOf(IAstModification.ReplaceNode(memread.addressExpression, typecast, memread))
         }
-        return super.visit(memread)
+        return noModifications
     }
 
-    override fun visit(memwrite: DirectMemoryWrite) {
+    override fun after(memwrite: DirectMemoryWrite, parent: Node): Iterable<IAstModification> {
+        // make sure the memory address is an uword
         val dt = memwrite.addressExpression.inferType(program)
         if(dt.isKnown && dt.typeOrElse(DataType.UWORD)!=DataType.UWORD) {
-            val literaladdr = memwrite.addressExpression as? NumericLiteralValue
-            if(literaladdr!=null) {
-                memwrite.addressExpression = literaladdr.cast(DataType.UWORD)
-            } else {
-                memwrite.addressExpression = TypecastExpression(memwrite.addressExpression, DataType.UWORD, true, memwrite.addressExpression.position)
-                memwrite.addressExpression.parent = memwrite
-            }
+            val typecast = (memwrite.addressExpression as? NumericLiteralValue)?.cast(DataType.UWORD)?.valueOrZero()
+                    ?: TypecastExpression(memwrite.addressExpression, DataType.UWORD, true, memwrite.addressExpression.position)
+            return listOf(IAstModification.ReplaceNode(memwrite.addressExpression, typecast, memwrite))
         }
-        super.visit(memwrite)
+        return noModifications
     }
 
-    override fun visit(structLv: StructLiteralValue): Expression {
-        val litval = super.visit(structLv)
-        if(litval !is StructLiteralValue)
-            return litval
-
-        val decl = litval.parent as? VarDecl
-        if(decl != null) {
-            val struct = decl.struct
-            if(struct != null) {
-                addTypecastsIfNeeded(litval, struct)
-            }
-        } else {
-            val assign = litval.parent as? Assignment
-            if (assign != null) {
-                val decl2 = assign.target.identifier?.targetVarDecl(program.namespace)
-                if(decl2 != null) {
-                    val struct = decl2.struct
-                    if(struct != null) {
-                        addTypecastsIfNeeded(litval, struct)
-                    }
+    override fun after(returnStmt: Return, parent: Node): Iterable<IAstModification> {
+        // add a typecast to the return type if it doesn't match the subroutine's signature
+        val returnValue = returnStmt.value
+        if(returnValue!=null) {
+            val subroutine = returnStmt.definingSubroutine()!!
+            if(subroutine.returntypes.size==1) {
+                val subReturnType = subroutine.returntypes.first()
+                if (returnValue.inferType(program).istype(subReturnType))
+                    return noModifications
+                if (returnValue is NumericLiteralValue) {
+                    val cast = returnValue.cast(subroutine.returntypes.single())
+                    if(cast.isValid)
+                        returnStmt.value = cast.valueOrZero()
+                } else {
+                    return listOf(IAstModification.ReplaceNode(
+                            returnValue,
+                            TypecastExpression(returnValue, subReturnType, true, returnValue.position),
+                            returnStmt))
                 }
             }
         }
-
-        return litval
-    }
-
-    private fun addTypecastsIfNeeded(structLv: StructLiteralValue, struct: StructDecl) {
-        structLv.values = struct.statements.zip(structLv.values).map {
-            val memberDt = (it.first as VarDecl).datatype
-            val valueDt = it.second.inferType(program)
-            if (valueDt.typeOrElse(memberDt) != memberDt)
-                TypecastExpression(it.second, memberDt, true, it.second.position)
-            else
-                it.second
-        }
+        return noModifications
     }
 }

compiler/src/prog8/ast/processing/VarInitValueAndAddressOfCreator.kt

@@ -1,156 +0,0 @@
-package prog8.ast.processing
-
-import prog8.ast.INameScope
-import prog8.ast.Module
-import prog8.ast.Node
-import prog8.ast.Program
-import prog8.ast.base.*
-import prog8.ast.expressions.*
-import prog8.ast.statements.*
-import prog8.compiler.CompilerException
-import prog8.functions.BuiltinFunctions
-import prog8.functions.FunctionSignature
-
-
-internal class VarInitValueAndAddressOfCreator(private val program: Program): IAstModifyingVisitor {
-    // For VarDecls that declare an initialization value:
-    // Replace the vardecl with an assignment (to set the initial value),
-    // and add a new vardecl with the default constant value of that type (usually zero) to the scope.
-    // This makes sure the variables get reset to the intended value on a next run of the program.
-    // Variable decls without a value don't get this treatment, which means they retain the last
-    // value they had when restarting the program.
-    // This is done in a separate step because it interferes with the namespace lookup of symbols
-    // in other ast processors.
-
-    // Also takes care to insert AddressOf (&) expression where required (string params to a UWORD function param etc).
-
-    private val vardeclsToAdd = mutableMapOf<INameScope, MutableList<VarDecl>>()
-
-    override fun visit(module: Module) {
-        vardeclsToAdd.clear()
-        super.visit(module)
-        // add any new vardecls to the various scopes
-        for((where, decls) in vardeclsToAdd) {
-            where.statements.addAll(0, decls)
-            decls.forEach { it.linkParents(where as Node) }
-        }
-    }
-
-    override fun visit(decl: VarDecl): Statement {
-        super.visit(decl)
-
-        if(decl.isArray && decl.value==null) {
-            // array datatype without initialization value, add list of zeros
-            val arraysize = decl.arraysize!!.size()!!
-            val array = ArrayLiteralValue(decl.datatype,
-                    Array(arraysize) { NumericLiteralValue.optimalInteger(0, decl.position) },
-                    decl.position)
-            decl.value = array
-        }
-
-        if(decl.type!= VarDeclType.VAR || decl.value==null)
-            return decl
-
-        if(decl.datatype in NumericDatatypes) {
-            val scope = decl.definingScope()
-            addVarDecl(scope, decl.asDefaultValueDecl(null))
-            val declvalue = decl.value!!
-            val value =
-                    if(declvalue is NumericLiteralValue)
-                        declvalue.cast(decl.datatype)
-                    else
-                        declvalue
-            val identifierName = listOf(decl.name)    // this was: (scoped name) decl.scopedname.split(".")
-            return VariableInitializationAssignment(
-                    AssignTarget(null, IdentifierReference(identifierName, decl.position), null, null, decl.position),
-                    null,
-                    value,
-                    decl.position
-            )
-        }
-
-        return decl
-    }
-
-    override fun visit(functionCall: FunctionCall): Expression {
-        var parentStatement: Node = functionCall
-        while(parentStatement !is Statement)
-            parentStatement = parentStatement.parent
-        val targetStatement = functionCall.target.targetSubroutine(program.namespace)
-        if(targetStatement!=null) {
-            addAddressOfExprIfNeeded(targetStatement, functionCall.args, parentStatement)
-        } else {
-            val builtinFunc = BuiltinFunctions[functionCall.target.nameInSource.joinToString (".")]
-            if(builtinFunc!=null)
-                addAddressOfExprIfNeededForBuiltinFuncs(builtinFunc, functionCall.args, parentStatement)
-        }
-        return functionCall
-    }
-
-    override fun visit(functionCallStatement: FunctionCallStatement): Statement {
-        val targetStatement = functionCallStatement.target.targetSubroutine(program.namespace)
-        if(targetStatement!=null) {
-            addAddressOfExprIfNeeded(targetStatement, functionCallStatement.args, functionCallStatement)
-        } else {
-            val builtinFunc = BuiltinFunctions[functionCallStatement.target.nameInSource.joinToString (".")]
-            if(builtinFunc!=null)
-                addAddressOfExprIfNeededForBuiltinFuncs(builtinFunc, functionCallStatement.args, functionCallStatement)
-        }
-        return functionCallStatement
-    }
-
-    private fun addAddressOfExprIfNeeded(subroutine: Subroutine, arglist: MutableList<Expression>, parent: Statement) {
-        // functions that accept UWORD and are given an array type, or string, will receive the AddressOf (memory location) of that value instead.
-        for(argparam in subroutine.parameters.withIndex().zip(arglist)) {
-            if(argparam.first.value.type==DataType.UWORD || argparam.first.value.type == DataType.STR) {
-                if(argparam.second is AddressOf)
-                    continue
-                val idref = argparam.second as? IdentifierReference
-                val strvalue = argparam.second as? StringLiteralValue
-                if(idref!=null) {
-                    val variable = idref.targetVarDecl(program.namespace)
-                    if(variable!=null && variable.datatype in IterableDatatypes) {
-                        val pointerExpr = AddressOf(idref, idref.position)
-                        pointerExpr.linkParents(arglist[argparam.first.index].parent)
-                        arglist[argparam.first.index] = pointerExpr
-                    }
-                }
-                else if(strvalue!=null) {
-                    // add a vardecl so that the autovar can be resolved in later lookups
-                    val variable = VarDecl.createAuto(strvalue)
-                    addVarDecl(strvalue.definingScope(), variable)
-                    // replace the argument with &autovar
-                    val autoHeapvarRef = IdentifierReference(listOf(variable.name), strvalue.position)
-                    val pointerExpr = AddressOf(autoHeapvarRef, strvalue.position)
-                    pointerExpr.linkParents(arglist[argparam.first.index].parent)
-                    arglist[argparam.first.index] = pointerExpr
-                }
-            }
-        }
-    }
-
-    private fun addAddressOfExprIfNeededForBuiltinFuncs(signature: FunctionSignature, args: MutableList<Expression>, parent: Statement) {
-        // val paramTypesForAddressOf = PassByReferenceDatatypes + DataType.UWORD
-        for(arg in args.withIndex().zip(signature.parameters)) {
-            val argvalue = arg.first.value
-            val argDt = argvalue.inferType(program)
-            if(argDt.typeOrElse(DataType.UBYTE) in PassByReferenceDatatypes && DataType.UWORD in arg.second.possibleDatatypes) {
-                if(argvalue !is IdentifierReference)
-                    throw CompilerException("pass-by-reference parameter isn't an identifier? $argvalue")
-                val addrOf = AddressOf(argvalue, argvalue.position)
-                args[arg.first.index] = addrOf
-                addrOf.linkParents(parent)
-            }
-        }
-    }
-
-
-    private fun addVarDecl(scope: INameScope, variable: VarDecl) {
-        if(scope !in vardeclsToAdd)
-            vardeclsToAdd[scope] = mutableListOf()
-        val declList = vardeclsToAdd.getValue(scope)
-        if(declList.all{it.name!=variable.name})
-            declList.add(variable)
-    }
-
-}

compiler/src/prog8/ast/processing/VariousCleanups.kt

@@ -0,0 +1,44 @@
+package prog8.ast.processing
+
+import prog8.ast.INameScope
+import prog8.ast.Node
+import prog8.ast.expressions.NumericLiteralValue
+import prog8.ast.expressions.TypecastExpression
+import prog8.ast.statements.AnonymousScope
+import prog8.ast.statements.NopStatement
+
+
+internal class VariousCleanups: AstWalker() {
+    private val noModifications = emptyList<IAstModification>()
+
+    override fun before(nopStatement: NopStatement, parent: Node): Iterable<IAstModification> {
+        return listOf(IAstModification.Remove(nopStatement, parent as INameScope))
+    }
+
+    override fun before(scope: AnonymousScope, parent: Node): Iterable<IAstModification> {
+        return if(parent is INameScope)
+            listOf(ScopeFlatten(scope, parent as INameScope))
+        else
+            noModifications
+    }
+
+    class ScopeFlatten(val scope: AnonymousScope, val into: INameScope) : IAstModification {
+        override fun perform() {
+            val idx = into.statements.indexOf(scope)
+            if(idx>=0) {
+                into.statements.addAll(idx+1, scope.statements)
+                into.statements.remove(scope)
+            }
+        }
+    }
+
+    override fun before(typecast: TypecastExpression, parent: Node): Iterable<IAstModification> {
+        if(typecast.expression is NumericLiteralValue) {
+            val value = (typecast.expression as NumericLiteralValue).cast(typecast.type)
+            if(value.isValid)
+                return listOf(IAstModification.ReplaceNode(typecast, value.valueOrZero(), parent))
+        }
+
+        return noModifications
+    }
+}

compiler/src/prog8/ast/processing/VerifyFunctionArgTypes.kt

@@ -0,0 +1,87 @@
+package prog8.ast.processing
+
+import prog8.ast.IFunctionCall
+import prog8.ast.INameScope
+import prog8.ast.Program
+import prog8.ast.base.DataType
+import prog8.ast.base.FatalAstException
+import prog8.ast.expressions.Expression
+import prog8.ast.expressions.FunctionCall
+import prog8.ast.statements.*
+import prog8.compiler.CompilerException
+import prog8.functions.BuiltinFunctions
+
+class VerifyFunctionArgTypes(val program: Program) : IAstVisitor {
+
+    override fun visit(functionCall: FunctionCall) {
+        val error = checkTypes(functionCall as IFunctionCall, functionCall.definingScope(), program)
+        if(error!=null)
+            throw CompilerException(error)
+    }
+
+    override fun visit(functionCallStatement: FunctionCallStatement) {
+        val error = checkTypes(functionCallStatement as IFunctionCall, functionCallStatement.definingScope(), program)
+        if (error!=null)
+            throw CompilerException(error)
+    }
+
+    companion object {
+
+        private fun argTypeCompatible(argDt: DataType, paramDt: DataType): Boolean {
+            if(argDt==paramDt)
+                return true
+
+            // there are some exceptions that are considered compatible, such as STR <> UWORD
+            if(argDt==DataType.STR && paramDt==DataType.UWORD ||
+                    argDt==DataType.UWORD && paramDt==DataType.STR)
+                return true
+
+            return false
+        }
+
+        fun checkTypes(call: IFunctionCall, scope: INameScope, program: Program): String? {
+            val argITypes = call.args.map { it.inferType(program) }
+            if(argITypes.any { !it.isKnown })
+                throw FatalAstException("unknown dt")
+            val argtypes = argITypes.map { it.typeOrElse(DataType.STRUCT) }
+            val target = call.target.targetStatement(scope)
+            if (target is Subroutine) {
+                if(call.args.size != target.parameters.size)
+                    return "invalid number of arguments"
+                val paramtypes = target.parameters.map { it.type }
+                val mismatch = argtypes.zip(paramtypes).indexOfFirst { !argTypeCompatible(it.first, it.second) }
+                if(mismatch>=0) {
+                    val actual = argtypes[mismatch].toString()
+                    val expected = paramtypes[mismatch].toString()
+                    return "argument ${mismatch + 1} type mismatch, was: $actual expected: $expected"
+                }
+                if(target.isAsmSubroutine) {
+                    if(target.asmReturnvaluesRegisters.size>1) {
+                        // multiple return values will NOT work inside an expression.
+                        // they MIGHT work in a regular assignment or just a function call statement.
+                        val parent = if(call is Statement) call.parent else if(call is Expression) call.parent else null
+                        if(call !is FunctionCallStatement && parent !is Assignment && parent !is VarDecl) {
+                            return "can't use subroutine call that returns multiple return values here (try moving it into a separate assignment)"
+                        }
+                    }
+                }
+            }
+            else if (target is BuiltinFunctionStatementPlaceholder) {
+                val func = BuiltinFunctions.getValue(target.name)
+                if(call.args.size != func.parameters.size)
+                    return "invalid number of arguments"
+                val paramtypes = func.parameters.map { it.possibleDatatypes }
+                argtypes.zip(paramtypes).forEachIndexed { index, pair ->
+                    val anyCompatible = pair.second.any { argTypeCompatible(pair.first, it) }
+                    if (!anyCompatible) {
+                        val actual = pair.first.toString()
+                        val expected = pair.second.toString()
+                        return "argument ${index + 1} type mismatch, was: $actual expected: $expected"
+                    }
+                }
+            }
+
+            return null
+        }
+    }
+}

compiler/src/prog8/compiler/BeforeAsmGenerationAstChanger.kt

@@ -0,0 +1,217 @@
+package prog8.compiler
+
+import prog8.ast.IFunctionCall
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.processing.AstWalker
+import prog8.ast.processing.IAstModification
+import prog8.ast.statements.*
+
+
+internal class BeforeAsmGenerationAstChanger(val program: Program, val errors: ErrorReporter) : AstWalker() {
+
+    private val noModifications = emptyList<IAstModification>()
+
+    override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
+        subroutineVariables.add(decl.name to decl)
+        if (decl.value == null && !decl.autogeneratedDontRemove && decl.type == VarDeclType.VAR && decl.datatype in NumericDatatypes) {
+            // a numeric vardecl without an initial value is initialized with zero,
+            // unless there's already an assignment below, that initializes the value
+            if(decl.allowInitializeWithZero)
+            {
+                val nextAssign = decl.definingScope().nextSibling(decl) as? Assignment
+                if (nextAssign != null && nextAssign.target.isSameAs(IdentifierReference(listOf(decl.name), Position.DUMMY)))
+                    decl.value = null
+                else
+                    decl.value = decl.zeroElementValue()
+            }
+        }
+        return noModifications
+    }
+
+    override fun after(assignment: Assignment, parent: Node): Iterable<IAstModification> {
+        // Try to replace A = B <operator> Something  by A= B, A = A <operator> Something
+        // this triggers the more efficent augmented assignment code generation more often.
+        // But it can only be done if the target variable IS NOT OCCURRING AS AN OPERAND ITSELF.
+        if(!assignment.isAugmentable
+                && assignment.target.identifier != null
+                && assignment.target.isInRegularRAM(program.namespace)) {
+            val binExpr = assignment.value as? BinaryExpression
+            if (binExpr != null && binExpr.operator !in comparisonOperators) {
+                if (binExpr.left !is BinaryExpression) {
+                    if (binExpr.right.referencesIdentifier(*assignment.target.identifier!!.nameInSource.toTypedArray())) {
+                        // the right part of the expression contains the target variable itself.
+                        // we can't 'split' it trivially because the variable will be changed halfway through.
+                        if(binExpr.operator in associativeOperators) {
+                            // A = <something-without-A>  <associativeoperator>  <otherthing-with-A>
+                            // use the other part of the expression to split.
+                            val assignRight = Assignment(assignment.target, binExpr.right, assignment.position)
+                            return listOf(
+                                    IAstModification.InsertBefore(assignment, assignRight, assignment.definingScope()),
+                                    IAstModification.ReplaceNode(binExpr.right, binExpr.left, binExpr),
+                                    IAstModification.ReplaceNode(binExpr.left, assignment.target.toExpression(), binExpr))
+                        }
+                    } else {
+                        val assignLeft = Assignment(assignment.target, binExpr.left, assignment.position)
+                        return listOf(
+                                IAstModification.InsertBefore(assignment, assignLeft, assignment.definingScope()),
+                                IAstModification.ReplaceNode(binExpr.left, assignment.target.toExpression(), binExpr))
+                    }
+                }
+            }
+        }
+        return noModifications
+    }
+
+    private val subroutineVariables = mutableListOf<Pair<String, VarDecl>>()
+
+    override fun before(subroutine: Subroutine, parent: Node): Iterable<IAstModification> {
+        subroutineVariables.clear()
+        return noModifications
+    }
+
+    override fun after(scope: AnonymousScope, parent: Node): Iterable<IAstModification> {
+        val decls = scope.statements.filterIsInstance<VarDecl>()
+        subroutineVariables.addAll(decls.map { it.name to it })
+
+        val sub = scope.definingSubroutine()
+        if (sub != null) {
+            // move vardecls of the scope into the upper scope. Make sure the position remains the same!
+            val numericVarsWithValue = decls.filter { it.value != null && it.datatype in NumericDatatypes }
+            val replaceVardecls =numericVarsWithValue.map {
+                val initValue = it.value!!  // assume here that value has always been set by now
+                it.value = null     // make sure no value init assignment for this vardecl will be created later (would be superfluous)
+                val target = AssignTarget(IdentifierReference(listOf(it.name), it.position), null, null, it.position)
+                val assign = Assignment(target, initValue, it.position)
+                initValue.parent = assign
+                IAstModification.ReplaceNode(it, assign, scope)
+            }
+            val moveVardeclsUp = decls.map { IAstModification.InsertFirst(it, sub) }
+            return replaceVardecls + moveVardeclsUp
+        }
+        return noModifications
+    }
+
+    override fun after(subroutine: Subroutine, parent: Node): Iterable<IAstModification> {
+        val firstDeclarations = mutableMapOf<String, VarDecl>()
+        for(decl in subroutineVariables) {
+            val existing = firstDeclarations[decl.first]
+            if(existing!=null && existing !== decl.second) {
+                errors.err("variable ${decl.first} already defined in subroutine ${subroutine.name} at ${existing.position}", decl.second.position)
+            } else {
+                firstDeclarations[decl.first] = decl.second
+            }
+        }
+
+
+        // add the implicit return statement at the end (if it's not there yet), but only if it's not a kernel routine.
+        // and if an assembly block doesn't contain a rts/rti, and some other situations.
+        val mods = mutableListOf<IAstModification>()
+        val returnStmt = Return(null, subroutine.position)
+        if (subroutine.asmAddress == null
+                && subroutine.statements.isNotEmpty()
+                && subroutine.amountOfRtsInAsm() == 0
+                && subroutine.statements.lastOrNull { it !is VarDecl } !is Return
+                && subroutine.statements.last() !is Subroutine) {
+            mods += IAstModification.InsertLast(returnStmt, subroutine)
+        }
+
+        // precede a subroutine with a return to avoid falling through into the subroutine from code above it
+        val outerScope = subroutine.definingScope()
+        val outerStatements = outerScope.statements
+        val subroutineStmtIdx = outerStatements.indexOf(subroutine)
+        if (subroutineStmtIdx > 0
+                && outerStatements[subroutineStmtIdx - 1] !is Jump
+                && outerStatements[subroutineStmtIdx - 1] !is Subroutine
+                && outerStatements[subroutineStmtIdx - 1] !is Return
+                && outerScope !is Block) {
+            mods += IAstModification.InsertAfter(outerStatements[subroutineStmtIdx - 1], returnStmt, outerScope)
+        }
+        return mods
+    }
+
+    override fun after(typecast: TypecastExpression, parent: Node): Iterable<IAstModification> {
+        // see if we can remove superfluous typecasts (outside of expressions)
+        // such as casting byte<->ubyte,  word<->uword
+        // Also the special typecast of a reference type (str, array) to an UWORD will be changed into address-of.
+        val sourceDt = typecast.expression.inferType(program).typeOrElse(DataType.STRUCT)
+        if (typecast.type in ByteDatatypes && sourceDt in ByteDatatypes
+                || typecast.type in WordDatatypes && sourceDt in WordDatatypes) {
+            if(typecast.parent !is Expression) {
+                return listOf(IAstModification.ReplaceNode(typecast, typecast.expression, parent))
+            }
+        }
+
+
+        // Note: for various reasons (most importantly, code simplicity), the code generator assumes/requires
+        // that the types of assignment values and their target are the same,
+        // and that the types of both operands of a binaryexpression node are the same.
+        // So, it is not easily possible to remove the typecasts that are there to make these conditions true.
+        // The only place for now where we can do this is for:
+        //    asmsub register pair parameter.
+
+        if(typecast.type in WordDatatypes) {
+            val fcall = typecast.parent as? IFunctionCall
+            if (fcall != null) {
+                val sub = fcall.target.targetStatement(program.namespace) as? Subroutine
+                if (sub != null && sub.isAsmSubroutine) {
+                    return listOf(IAstModification.ReplaceNode(typecast, typecast.expression, parent))
+                }
+            }
+        }
+
+        if(sourceDt in PassByReferenceDatatypes) {
+            if(typecast.type==DataType.UWORD) {
+                if(typecast.expression is IdentifierReference) {
+                    return listOf(IAstModification.ReplaceNode(
+                            typecast,
+                            AddressOf(typecast.expression as IdentifierReference, typecast.position),
+                            parent
+                    ))
+                } else if(typecast.expression is IFunctionCall) {
+                    return listOf(IAstModification.ReplaceNode(
+                            typecast,
+                            typecast.expression,
+                            parent
+                    ))
+                }
+            } else {
+                errors.err("cannot cast pass-by-reference value to type ${typecast.type} (only to UWORD)", typecast.position)
+            }
+        }
+
+        return noModifications
+    }
+
+    override fun after(ifStatement: IfStatement, parent: Node): Iterable<IAstModification> {
+        val binExpr = ifStatement.condition as? BinaryExpression
+        if(binExpr==null || binExpr.operator !in comparisonOperators) {
+            // if x  ->  if x!=0,    if x+5  ->  if x+5 != 0
+            val booleanExpr = BinaryExpression(ifStatement.condition, "!=", NumericLiteralValue.optimalInteger(0, ifStatement.condition.position), ifStatement.condition.position)
+            return listOf(IAstModification.ReplaceNode(ifStatement.condition, booleanExpr, ifStatement))
+        }
+        return noModifications
+    }
+
+    override fun after(untilLoop: UntilLoop, parent: Node): Iterable<IAstModification> {
+        val binExpr = untilLoop.condition as? BinaryExpression
+        if(binExpr==null || binExpr.operator !in comparisonOperators) {
+            // until x  ->  until x!=0,    until x+5  ->  until x+5 != 0
+            val booleanExpr = BinaryExpression(untilLoop.condition, "!=", NumericLiteralValue.optimalInteger(0, untilLoop.condition.position), untilLoop.condition.position)
+            return listOf(IAstModification.ReplaceNode(untilLoop.condition, booleanExpr, untilLoop))
+        }
+        return noModifications
+    }
+
+    override fun after(whileLoop: WhileLoop, parent: Node): Iterable<IAstModification> {
+        val binExpr = whileLoop.condition as? BinaryExpression
+        if(binExpr==null || binExpr.operator !in comparisonOperators) {
+            // while x  ->  while x!=0,    while x+5  ->  while x+5 != 0
+            val booleanExpr = BinaryExpression(whileLoop.condition, "!=", NumericLiteralValue.optimalInteger(0, whileLoop.condition.position), whileLoop.condition.position)
+            return listOf(IAstModification.ReplaceNode(whileLoop.condition, booleanExpr, whileLoop))
+        }
+        return noModifications
+    }
+}

compiler/src/prog8/compiler/Compiler.kt

@@ -27,7 +27,10 @@ data class CompilationOptions(val output: OutputType,
                               val launcher: LauncherType,
                               val zeropage: ZeropageType,
                               val zpReserved: List<IntRange>,
-                              val floats: Boolean)
+                              val floats: Boolean,
+                              val noSysInit: Boolean) {
+    var slowCodegenWarnings = false
+}
 
 
 class CompilerException(message: String?) : Exception(message)

compiler/src/prog8/compiler/Main.kt

@@ -4,15 +4,19 @@ import prog8.ast.AstToSourceCode
 import prog8.ast.Program
 import prog8.ast.base.*
 import prog8.ast.statements.Directive
+import prog8.compiler.target.C64Target
 import prog8.compiler.target.CompilationTarget
+import prog8.compiler.target.Cx16Target
+import prog8.optimizer.*
+import prog8.optimizer.UnusedCodeRemover
 import prog8.optimizer.constantFold
 import prog8.optimizer.optimizeStatements
 import prog8.optimizer.simplifyExpressions
+import prog8.parser.ModuleImporter
 import prog8.parser.ParsingFailedError
-import prog8.parser.importLibraryModule
-import prog8.parser.importModule
 import prog8.parser.moduleName
 import java.nio.file.Path
+import kotlin.system.exitProcess
 import kotlin.system.measureTimeMillis
 
 
@@ -25,90 +29,44 @@ class CompilationResult(val success: Boolean,
 fun compileProgram(filepath: Path,
                    optimize: Boolean,
                    writeAssembly: Boolean,
+                   slowCodegenWarnings: Boolean,
+                   compilationTarget: String,
                    outputDir: Path): CompilationResult {
+    var programName = ""
     lateinit var programAst: Program
-    var programName: String? = null
+    lateinit var importedFiles: List<Path>
+    val errors = ErrorReporter()
 
-    var importedFiles: List<Path> = emptyList()
-    var success=false
+    when(compilationTarget) {
+        C64Target.name -> CompilationTarget.instance = C64Target
+        Cx16Target.name -> CompilationTarget.instance = Cx16Target
+        else -> {
+            System.err.println("invalid compilation target")
+            exitProcess(1)
+        }
+    }
 
     try {
         val totalTime = measureTimeMillis {
             // import main module and everything it needs
-            println("Parsing...")
-            programAst = Program(moduleName(filepath.fileName), mutableListOf())
-            importModule(programAst, filepath)
-
-            importedFiles = programAst.modules.filter { !it.source.startsWith("@embedded@") }.map{ it.source }
-
-            val compilerOptions = determineCompilationOptions(programAst)
-            if (compilerOptions.launcher == LauncherType.BASIC && compilerOptions.output != OutputType.PRG)
-                throw ParsingFailedError("${programAst.modules.first().position} BASIC launcher requires output type PRG.")
-
-            // if we're producing a PRG or BASIC program, include the c64utils and c64lib libraries
-            if (compilerOptions.launcher == LauncherType.BASIC || compilerOptions.output == OutputType.PRG) {
-                importLibraryModule(programAst, "c64lib")
-                importLibraryModule(programAst, "c64utils")
-            }
-
-            // always import prog8lib and math
-            importLibraryModule(programAst, "math")
-            importLibraryModule(programAst, "prog8lib")
-
-
-            // perform initial syntax checks and constant folding
-            println("Syntax check...")
-            val time1 = measureTimeMillis {
-                programAst.checkIdentifiers()
-            }
-
-            //println(" time1: $time1")
-            val time2 = measureTimeMillis {
-                programAst.constantFold()
-            }
-            //println(" time2: $time2")
-            val time3 = measureTimeMillis {
-                programAst.removeNopsFlattenAnonScopes()
-                programAst.reorderStatements()
-                programAst.addTypecasts()
-            }
-            //println(" time3: $time3")
-            val time4 = measureTimeMillis {
-                programAst.checkValid(compilerOptions)          // check if tree is valid
-            }
-            //println(" time4: $time4")
-
-            programAst.checkIdentifiers()
-            if (optimize) {
-                // optimize the parse tree
-                println("Optimizing...")
-                while (true) {
-                    // keep optimizing expressions and statements until no more steps remain
-                    val optsDone1 = programAst.simplifyExpressions()
-                    val optsDone2 = programAst.optimizeStatements()
-                    if (optsDone1 + optsDone2 == 0)
-                        break
-                }
-            }
-
-            programAst.addTypecasts()
-            programAst.removeNopsFlattenAnonScopes()
-            programAst.checkValid(compilerOptions)          // check if final tree is valid
-            programAst.checkRecursion()         // check if there are recursive subroutine calls
+            val (ast, compilationOptions, imported) = parseImports(filepath, errors)
+            compilationOptions.slowCodegenWarnings = slowCodegenWarnings
+            programAst = ast
+            importedFiles = imported
+            processAst(programAst, errors, compilationOptions)
+            if (optimize)
+                optimizeAst(programAst, errors)
+            postprocessAst(programAst, errors, compilationOptions)
 
             // printAst(programAst)
 
-            if(writeAssembly) {
-                // asm generation directly from the Ast, no need for intermediate code
-                val zeropage = CompilationTarget.machine.getZeropage(compilerOptions)
-                programAst.anonscopeVarsCleanup()
-                val assembly = CompilationTarget.asmGenerator(programAst, zeropage, compilerOptions, outputDir).compileToAssembly(optimize)
-                assembly.assemble(compilerOptions)
-                programName = assembly.name
-            }
-            success = true
+            if(writeAssembly)
+                programName = writeAssembly(programAst, errors, outputDir, optimize, compilationOptions)
         }
+        System.out.flush()
+        System.err.flush()
         println("\nTotal compilation+assemble time: ${totalTime / 1000.0} sec.")
+        return CompilationResult(true, programAst, programName, importedFiles)
 
     } catch (px: ParsingFailedError) {
         System.err.print("\u001b[91m")  // bright red
@@ -131,16 +89,32 @@ fun compileProgram(filepath: Path,
         System.out.flush()
         throw x
     }
-    return CompilationResult(success, programAst, programName ?: "", importedFiles)
+
+    return CompilationResult(false, Program("failed", mutableListOf()), programName, emptyList())
 }
 
-fun printAst(programAst: Program) {
-    println()
-    val printer = AstToSourceCode(::print, programAst)
-    printer.visit(programAst)
-    println()
-}
+private fun parseImports(filepath: Path, errors: ErrorReporter): Triple<Program, CompilationOptions, List<Path>> {
+    println("Compiler target: ${CompilationTarget.instance.name}. Parsing...")
+    val importer = ModuleImporter()
+    val programAst = Program(moduleName(filepath.fileName), mutableListOf())
+    importer.importModule(programAst, filepath)
+    errors.handle()
 
+    val importedFiles = programAst.modules.filter { !it.source.startsWith("@embedded@") }.map { it.source }
+
+    val compilerOptions = determineCompilationOptions(programAst)
+    if (compilerOptions.launcher == LauncherType.BASIC && compilerOptions.output != OutputType.PRG)
+        throw ParsingFailedError("${programAst.modules.first().position} BASIC launcher requires output type PRG.")
+
+    // depending on the machine and compiler options we may have to include some libraries
+    CompilationTarget.instance.machine.importLibs(compilerOptions, importer, programAst)
+
+    // always import prog8_lib and math
+    importer.importLibraryModule(programAst, "math")
+    importer.importLibraryModule(programAst, "prog8_lib")
+    errors.handle()
+    return Triple(programAst, compilerOptions, importedFiles)
+}
 
 private fun determineCompilationOptions(program: Program): CompilationOptions {
     val mainModule = program.modules.first()
@@ -148,13 +122,12 @@ private fun determineCompilationOptions(program: Program): CompilationOptions {
             as? Directive)?.args?.single()?.name?.toUpperCase()
     val launcherType = (mainModule.statements.singleOrNull { it is Directive && it.directive == "%launcher" }
             as? Directive)?.args?.single()?.name?.toUpperCase()
-    mainModule.loadAddress = (mainModule.statements.singleOrNull { it is Directive && it.directive == "%address" }
-            as? Directive)?.args?.single()?.int ?: 0
     val zpoption: String? = (mainModule.statements.singleOrNull { it is Directive && it.directive == "%zeropage" }
             as? Directive)?.args?.single()?.name?.toUpperCase()
     val allOptions = program.modules.flatMap { it.statements }.filter { it is Directive && it.directive == "%option" }.flatMap { (it as Directive).args }.toSet()
     val floatsEnabled = allOptions.any { it.name == "enable_floats" }
-    val zpType: ZeropageType =
+    val noSysInit = allOptions.any { it.name == "no_sysinit" }
+    var zpType: ZeropageType =
             if (zpoption == null)
                 if(floatsEnabled) ZeropageType.FLOATSAFE else ZeropageType.KERNALSAFE
             else
@@ -164,6 +137,12 @@ private fun determineCompilationOptions(program: Program): CompilationOptions {
                     ZeropageType.KERNALSAFE
                     // error will be printed by the astchecker
                 }
+
+    if (zpType==ZeropageType.FLOATSAFE && CompilationTarget.instance.name == Cx16Target.name) {
+        System.err.println("Warning: Cx16 target must use zp option basicsafe instead of floatsafe")
+        zpType = ZeropageType.BASICSAFE
+    }
+
     val zpReserved = mainModule.statements
             .asSequence()
             .filter { it is Directive && it.directive == "%zpreserved" }
@@ -171,9 +150,97 @@ private fun determineCompilationOptions(program: Program): CompilationOptions {
             .map { it[0].int!!..it[1].int!! }
             .toList()
 
+    if(outputType!=null && !OutputType.values().any {it.name==outputType}) {
+        System.err.println("invalid output type $outputType")
+        exitProcess(1)
+    }
+    if(launcherType!=null && !LauncherType.values().any {it.name==launcherType}) {
+        System.err.println("invalid launcher type $launcherType")
+        exitProcess(1)
+    }
+
     return CompilationOptions(
             if (outputType == null) OutputType.PRG else OutputType.valueOf(outputType),
             if (launcherType == null) LauncherType.BASIC else LauncherType.valueOf(launcherType),
-            zpType, zpReserved, floatsEnabled
+            zpType, zpReserved, floatsEnabled, noSysInit
     )
 }
+
+private fun processAst(programAst: Program, errors: ErrorReporter, compilerOptions: CompilationOptions) {
+    // perform initial syntax checks and processings
+    println("Processing for target ${CompilationTarget.instance.name}...")
+    programAst.checkIdentifiers(errors)
+    errors.handle()
+    programAst.constantFold(errors)
+    errors.handle()
+    programAst.reorderStatements(errors)
+    errors.handle()
+    programAst.addTypecasts(errors)
+    errors.handle()
+    programAst.variousCleanups()
+    programAst.checkValid(compilerOptions, errors)
+    errors.handle()
+    programAst.checkIdentifiers(errors)
+    errors.handle()
+}
+
+private fun optimizeAst(programAst: Program, errors: ErrorReporter) {
+    // optimize the parse tree
+    println("Optimizing...")
+    while (true) {
+        // keep optimizing expressions and statements until no more steps remain
+        val optsDone1 = programAst.simplifyExpressions()
+        val optsDone2 = programAst.splitBinaryExpressions()
+        val optsDone3 = programAst.optimizeStatements(errors)
+        programAst.constantFold(errors) // because simplified statements and expressions can result in more constants that can be folded away
+        errors.handle()
+        if (optsDone1 + optsDone2 + optsDone3 == 0)
+            break
+    }
+
+    val remover = UnusedCodeRemover(programAst, errors)
+    remover.visit(programAst)
+    remover.applyModifications()
+    errors.handle()
+}
+
+private fun postprocessAst(programAst: Program, errors: ErrorReporter, compilerOptions: CompilationOptions) {
+    programAst.addTypecasts(errors)
+    errors.handle()
+    programAst.variousCleanups()
+    programAst.checkValid(compilerOptions, errors)          // check if final tree is still valid
+    errors.handle()
+    val callGraph = CallGraph(programAst)
+    callGraph.checkRecursiveCalls(errors)
+    errors.handle()
+    programAst.verifyFunctionArgTypes()
+    programAst.moveMainAndStartToFirst()
+}
+
+private fun writeAssembly(programAst: Program, errors: ErrorReporter, outputDir: Path,
+                          optimize: Boolean, compilerOptions: CompilationOptions): String {
+    // asm generation directly from the Ast,
+    programAst.processAstBeforeAsmGeneration(errors)
+    errors.handle()
+
+    // printAst(programAst)
+
+    CompilationTarget.instance.machine.initializeZeropage(compilerOptions)
+    val assembly = CompilationTarget.instance.asmGenerator(
+            programAst,
+            errors,
+            CompilationTarget.instance.machine.zeropage,
+            compilerOptions,
+            outputDir).compileToAssembly(optimize)
+    assembly.assemble(compilerOptions)
+    errors.handle()
+    return assembly.name
+}
+
+fun printAst(programAst: Program) {
+    println()
+    val printer = AstToSourceCode(::print, programAst)
+    printer.visit(programAst)
+    println()
+}
+

compiler/src/prog8/compiler/Zeropage.kt

@@ -8,6 +8,12 @@ class ZeropageDepletedError(message: String) : Exception(message)
 
 abstract class Zeropage(protected val options: CompilationOptions) {
 
+    abstract val SCRATCH_B1 : Int      // temp storage for a single byte
+    abstract val SCRATCH_REG : Int     // temp storage for a register
+    abstract val SCRATCH_W1 : Int      // temp storage 1 for a word  $fb+$fc
+    abstract val SCRATCH_W2 : Int      // temp storage 2 for a word  $fb+$fc
+
+
     private val allocations = mutableMapOf<Int, Pair<String, DataType>>()
     val free = mutableListOf<Int>()     // subclasses must set this to the appropriate free locations.
 
@@ -15,8 +21,8 @@ abstract class Zeropage(protected val options: CompilationOptions) {
 
     fun available() = if(options.zeropage==ZeropageType.DONTUSE) 0 else free.size
 
-    fun allocate(scopedname: String, datatype: DataType, position: Position?): Int {
-        assert(scopedname.isEmpty() || !allocations.values.any { it.first==scopedname } ) {"isSameAs scopedname can't be allocated twice"}
+    fun allocate(scopedname: String, datatype: DataType, position: Position?, errors: ErrorReporter): Int {
+        assert(scopedname.isEmpty() || !allocations.values.any { it.first==scopedname } ) {"scopedname can't be allocated twice"}
 
         if(options.zeropage==ZeropageType.DONTUSE)
             throw CompilerException("zero page usage has been disabled")
@@ -28,9 +34,9 @@ abstract class Zeropage(protected val options: CompilationOptions) {
                     DataType.FLOAT -> {
                         if (options.floats) {
                             if(position!=null)
-                                printWarning("allocated a large value (float) in zeropage", position)
+                                errors.warn("allocated a large value (float) in zeropage", position)
                             else
-                                printWarning("$scopedname: allocated a large value (float) in zeropage")
+                                errors.warn("$scopedname: allocated a large value (float) in zeropage", position ?: Position.DUMMY)
                             5
                         } else throw CompilerException("floating point option not enabled")
                     }
@@ -39,13 +45,13 @@ abstract class Zeropage(protected val options: CompilationOptions) {
 
         if(free.size > 0) {
             if(size==1) {
-                for(candidate in free.min()!! .. free.max()!!+1) {
+                for(candidate in free.minOrNull()!! .. free.maxOrNull()!!+1) {
                     if(loneByte(candidate))
                         return makeAllocation(candidate, 1, datatype, scopedname)
                 }
                 return makeAllocation(free[0], 1, datatype, scopedname)
             }
-            for(candidate in free.min()!! .. free.max()!!+1) {
+            for(candidate in free.minOrNull()!! .. free.maxOrNull()!!+1) {
                 if (sequentialFree(candidate, size))
                     return makeAllocation(candidate, size, datatype, scopedname)
             }
@@ -58,18 +64,10 @@ abstract class Zeropage(protected val options: CompilationOptions) {
 
     private fun makeAllocation(address: Int, size: Int, datatype: DataType, name: String?): Int {
         free.removeAll(address until address+size)
-        allocations[address] = Pair(name ?: "<unnamed>", datatype)
+        allocations[address] = (name ?: "<unnamed>") to datatype
         return address
     }
 
     private fun loneByte(address: Int) = address in free && address-1 !in free && address+1 !in free
     private fun sequentialFree(address: Int, size: Int) = free.containsAll((address until address+size).toList())
-
-    enum class ExitProgramStrategy {
-        CLEAN_EXIT,
-        SYSTEM_RESET
-    }
-
-    abstract val exitProgramStrategy: ExitProgramStrategy
-
 }

compiler/src/prog8/compiler/target/CompilationTarget.kt

@@ -1,16 +1,47 @@
 package prog8.compiler.target
 
 import prog8.ast.Program
+import prog8.ast.base.ErrorReporter
 import prog8.compiler.CompilationOptions
 import prog8.compiler.Zeropage
+import prog8.compiler.target.c64.C64MachineDefinition
+import prog8.compiler.target.c64.Petscii
+import prog8.compiler.target.c64.codegen.AsmGen
+import prog8.compiler.target.cx16.CX16MachineDefinition
 import java.nio.file.Path
 
+
 internal interface CompilationTarget {
+    val name: String
+    val machine: IMachineDefinition
+    fun encodeString(str: String, altEncoding: Boolean): List<Short>
+    fun decodeString(bytes: List<Short>, altEncoding: Boolean): String
+    fun asmGenerator(program: Program, errors: ErrorReporter, zp: Zeropage, options: CompilationOptions, path: Path): IAssemblyGenerator
+
     companion object {
-        lateinit var name: String
-        lateinit var machine: IMachineDefinition
-        lateinit var encodeString: (str: String) -> List<Short>
-        lateinit var decodeString: (bytes: List<Short>) -> String
-        lateinit var asmGenerator: (Program, Zeropage, CompilationOptions, Path) -> IAssemblyGenerator
+        lateinit var instance: CompilationTarget
     }
 }
+
+
+internal object C64Target: CompilationTarget {
+    override val name = "c64"
+    override val machine = C64MachineDefinition
+    override fun encodeString(str: String, altEncoding: Boolean) =
+            if(altEncoding) Petscii.encodeScreencode(str, true) else Petscii.encodePetscii(str, true)
+    override fun decodeString(bytes: List<Short>, altEncoding: Boolean) =
+            if(altEncoding) Petscii.decodeScreencode(bytes, true) else Petscii.decodePetscii(bytes, true)
+    override fun asmGenerator(program: Program, errors: ErrorReporter, zp: Zeropage, options: CompilationOptions, path: Path) =
+            AsmGen(program, errors, zp, options, path)
+}
+
+internal object Cx16Target: CompilationTarget {
+    override val name = "cx16"
+    override val machine = CX16MachineDefinition
+    override fun encodeString(str: String, altEncoding: Boolean) =
+            if(altEncoding) Petscii.encodeScreencode(str, true) else Petscii.encodePetscii(str, true)
+    override fun decodeString(bytes: List<Short>, altEncoding: Boolean) =
+            if(altEncoding) Petscii.decodeScreencode(bytes, true) else Petscii.decodePetscii(bytes, true)
+    override fun asmGenerator(program: Program, errors: ErrorReporter, zp: Zeropage, options: CompilationOptions, path: Path) =
+            AsmGen(program, errors, zp, options, path)
+}

compiler/src/prog8/compiler/target/IAssemblyGenerator.kt

@@ -6,6 +6,10 @@ internal interface IAssemblyGenerator {
     fun compileToAssembly(optimize: Boolean): IAssemblyProgram
 }
 
+internal const val generatedLabelPrefix = "_prog8_label_"
+internal const val subroutineFloatEvalResultVar1 = "_prog8_float_eval_result1"
+internal const val subroutineFloatEvalResultVar2 = "_prog8_float_eval_result2"
+
 internal interface IAssemblyProgram {
     val name: String
     fun assemble(options: CompilationOptions)

compiler/src/prog8/compiler/target/IMachineDefinition.kt

@@ -1,15 +1,39 @@
 package prog8.compiler.target
 
+import prog8.ast.Program
 import prog8.compiler.CompilationOptions
 import prog8.compiler.Zeropage
+import prog8.parser.ModuleImporter
 
 
-interface IMachineDefinition {
+internal interface IMachineFloat {
+    fun toDouble(): Double
+    fun makeFloatFillAsm(): String
+}
+
+internal enum class CpuType {
+    CPU6502,
+    CPU65c02
+}
+
+internal interface IMachineDefinition {
     val FLOAT_MAX_NEGATIVE: Double
     val FLOAT_MAX_POSITIVE: Double
     val FLOAT_MEM_SIZE: Int
+    val POINTER_MEM_SIZE: Int
+    val ESTACK_LO: Int
+    val ESTACK_HI: Int
+    val BASIC_LOAD_ADDRESS : Int
+    val RAW_LOAD_ADDRESS : Int
 
     val opcodeNames: Set<String>
+    var zeropage: Zeropage
+    val cpu: CpuType
 
-    fun getZeropage(compilerOptions: CompilationOptions): Zeropage
+    fun initializeZeropage(compilerOptions: CompilationOptions)
+    fun getFloat(num: Number): IMachineFloat
+    fun getFloatRomConst(number: Double): String?
+    fun importLibs(compilerOptions: CompilationOptions, importer: ModuleImporter, program: Program)
+    fun launchEmulator(programName: String)
+    fun isRegularRAMaddress(address: Int): Boolean
 }

compiler/src/prog8/compiler/target/c64/AssemblyProgram.kt

@@ -2,31 +2,33 @@ package prog8.compiler.target.c64
 
 import prog8.compiler.CompilationOptions
 import prog8.compiler.OutputType
+import prog8.compiler.target.CompilationTarget
 import prog8.compiler.target.IAssemblyProgram
+import prog8.compiler.target.generatedLabelPrefix
 import java.nio.file.Path
 import kotlin.system.exitProcess
 
-class AssemblyProgram(override val name: String, outputDir: Path): IAssemblyProgram {
+class AssemblyProgram(override val name: String, outputDir: Path) : IAssemblyProgram {
     private val assemblyFile = outputDir.resolve("$name.asm")
     private val prgFile = outputDir.resolve("$name.prg")
     private val binFile = outputDir.resolve("$name.bin")
     private val viceMonListFile = outputDir.resolve("$name.vice-mon-list")
 
     override fun assemble(options: CompilationOptions) {
-        // add "-Wlong-branch"  to see warnings about conversion of branch instructions to jumps
+        // add "-Wlong-branch"  to see warnings about conversion of branch instructions to jumps (default = do this silently)
         val command = mutableListOf("64tass", "--ascii", "--case-sensitive", "--long-branch",
-                "-Wall", "-Wno-strict-bool", "-Wno-shadow", "-Werror", "-Wno-error=long-branch",
+                "-Wall", "-Wno-strict-bool", "-Wno-shadow", // "-Werror",
                 "--dump-labels", "--vice-labels", "-l", viceMonListFile.toString(), "--no-monitor")
 
-        val outFile = when(options.output) {
+        val outFile = when (options.output) {
             OutputType.PRG -> {
                 command.add("--cbm-prg")
-                println("\nCreating C-64 prg.")
+                println("\nCreating prg for target ${CompilationTarget.instance.name}.")
                 prgFile
             }
             OutputType.RAW -> {
                 command.add("--nostart")
-                println("\nCreating raw binary.")
+                println("\nCreating raw binary for target ${CompilationTarget.instance.name}.")
                 binFile
             }
         }
@@ -34,27 +36,39 @@ class AssemblyProgram(override val name: String, outputDir: Path): IAssemblyProg
 
         val proc = ProcessBuilder(command).inheritIO().start()
         val result = proc.waitFor()
-        if(result!=0) {
+        if (result != 0) {
             System.err.println("assembler failed with returncode $result")
             exitProcess(result)
         }
 
+        removeGeneratedLabelsFromMonlist()
         generateBreakpointList()
     }
 
+    private fun removeGeneratedLabelsFromMonlist() {
+        val pattern = Regex("""al (\w+) \S+${generatedLabelPrefix}.+?""")
+        val lines = viceMonListFile.toFile().readLines()
+        viceMonListFile.toFile().outputStream().bufferedWriter().use {
+            for (line in lines) {
+                if(pattern.matchEntire(line)==null)
+                    it.write(line+"\n")
+            }
+        }
+    }
+
     private fun generateBreakpointList() {
         // builds list of breakpoints, appends to monitor list file
         val breakpoints = mutableListOf<String>()
-        val pattern = Regex("""al (\w+) \S+_prog8_breakpoint_\d+.?""")      // gather breakpoints by the source label that"s generated for them
-        for(line in viceMonListFile.toFile().readLines()) {
+        val pattern = Regex("""al (\w+) \S+_prog8_breakpoint_\d+.?""")      // gather breakpoints by the source label that's generated for them
+        for (line in viceMonListFile.toFile().readLines()) {
             val match = pattern.matchEntire(line)
-            if(match!=null)
-            breakpoints.add("break \$" + match.groupValues[1])
+            if (match != null)
+                breakpoints.add("break \$" + match.groupValues[1])
         }
         val num = breakpoints.size
         breakpoints.add(0, "; vice monitor breakpoint list now follows")
         breakpoints.add(1, "; $num breakpoints have been defined")
         breakpoints.add(2, "del")
-        viceMonListFile.toFile().appendText(breakpoints.joinToString("\n")+"\n")
+        viceMonListFile.toFile().appendText(breakpoints.joinToString("\n") + "\n")
     }
 }

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

@@ -1,37 +1,99 @@
 package prog8.compiler.target.c64
 
-import prog8.compiler.CompilationOptions
-import prog8.compiler.CompilerException
-import prog8.compiler.Zeropage
-import prog8.compiler.ZeropageType
+import prog8.ast.Program
+import prog8.compiler.*
+import prog8.compiler.target.CpuType
 import prog8.compiler.target.IMachineDefinition
-import java.awt.Color
-import java.awt.image.BufferedImage
-import javax.imageio.ImageIO
+import prog8.compiler.target.IMachineFloat
+import prog8.parser.ModuleImporter
+import java.io.IOException
+import java.math.RoundingMode
 import kotlin.math.absoluteValue
 import kotlin.math.pow
 
-object C64MachineDefinition: IMachineDefinition {
+internal object C64MachineDefinition: IMachineDefinition {
+
+    override val cpu = CpuType.CPU6502
 
     // 5-byte cbm MFLPT format limitations:
     override val FLOAT_MAX_POSITIVE = 1.7014118345e+38         // bytes: 255,127,255,255,255
     override val FLOAT_MAX_NEGATIVE = -1.7014118345e+38        // bytes: 255,255,255,255,255
     override val FLOAT_MEM_SIZE = 5
-    const val BASIC_LOAD_ADDRESS = 0x0801
-    const val RAW_LOAD_ADDRESS = 0xc000
+    override val POINTER_MEM_SIZE = 2
+    override val BASIC_LOAD_ADDRESS = 0x0801
+    override val RAW_LOAD_ADDRESS = 0xc000
 
     // the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
     // and some heavily used string constants derived from the two values above
-    const val ESTACK_LO_VALUE       = 0xce00        //  $ce00-$ceff inclusive
-    const val ESTACK_HI_VALUE       = 0xcf00        //  $cf00-$cfff inclusive
-    const val ESTACK_LO_HEX         = "\$ce00"
-    const val ESTACK_LO_PLUS1_HEX   = "\$ce01"
-    const val ESTACK_LO_PLUS2_HEX   = "\$ce02"
-    const val ESTACK_HI_HEX         = "\$cf00"
-    const val ESTACK_HI_PLUS1_HEX   = "\$cf01"
-    const val ESTACK_HI_PLUS2_HEX   = "\$cf02"
+    override val ESTACK_LO = 0xce00        //  $ce00-$ceff inclusive
+    override val ESTACK_HI = 0xcf00        //  $ce00-$ceff inclusive
 
-    override fun getZeropage(compilerOptions: CompilationOptions) = C64Zeropage(compilerOptions)
+    override lateinit var zeropage: Zeropage
+
+    override fun getFloat(num: Number) = Mflpt5.fromNumber(num)
+
+    override fun getFloatRomConst(number: Double): String? {
+        // try to match the ROM float constants to save memory
+        val mflpt5 = Mflpt5.fromNumber(number)
+        val floatbytes = shortArrayOf(mflpt5.b0, mflpt5.b1, mflpt5.b2, mflpt5.b3, mflpt5.b4)
+        when {
+            floatbytes.contentEquals(shortArrayOf(0x00, 0x00, 0x00, 0x00, 0x00)) -> return "floats.FL_ZERO_const"        // not a ROM const
+            floatbytes.contentEquals(shortArrayOf(0x81, 0x00, 0x00, 0x00, 0x00)) -> return "floats.FL_ONE_const"        // not a ROM const
+            floatbytes.contentEquals(shortArrayOf(0x82, 0x49, 0x0f, 0xda, 0xa1)) -> return "floats.FL_PIVAL"
+            floatbytes.contentEquals(shortArrayOf(0x90, 0x80, 0x00, 0x00, 0x00)) -> return "floats.FL_N32768"
+            floatbytes.contentEquals(shortArrayOf(0x81, 0x00, 0x00, 0x00, 0x00)) -> return "floats.FL_FONE"
+            floatbytes.contentEquals(shortArrayOf(0x80, 0x35, 0x04, 0xf3, 0x34)) -> return "floats.FL_SQRHLF"
+            floatbytes.contentEquals(shortArrayOf(0x81, 0x35, 0x04, 0xf3, 0x34)) -> return "floats.FL_SQRTWO"
+            floatbytes.contentEquals(shortArrayOf(0x80, 0x80, 0x00, 0x00, 0x00)) -> return "floats.FL_NEGHLF"
+            floatbytes.contentEquals(shortArrayOf(0x80, 0x31, 0x72, 0x17, 0xf8)) -> return "floats.FL_LOG2"
+            floatbytes.contentEquals(shortArrayOf(0x84, 0x20, 0x00, 0x00, 0x00)) -> return "floats.FL_TENC"
+            floatbytes.contentEquals(shortArrayOf(0x9e, 0x6e, 0x6b, 0x28, 0x00)) -> return "floats.FL_NZMIL"
+            floatbytes.contentEquals(shortArrayOf(0x80, 0x00, 0x00, 0x00, 0x00)) -> return "floats.FL_FHALF"
+            floatbytes.contentEquals(shortArrayOf(0x81, 0x38, 0xaa, 0x3b, 0x29)) -> return "floats.FL_LOGEB2"
+            floatbytes.contentEquals(shortArrayOf(0x81, 0x49, 0x0f, 0xda, 0xa2)) -> return "floats.FL_PIHALF"
+            floatbytes.contentEquals(shortArrayOf(0x83, 0x49, 0x0f, 0xda, 0xa2)) -> return "floats.FL_TWOPI"
+            floatbytes.contentEquals(shortArrayOf(0x7f, 0x00, 0x00, 0x00, 0x00)) -> return "floats.FL_FR4"
+            else -> {
+                // attempt to correct for a few rounding issues
+                when (number.toBigDecimal().setScale(10, RoundingMode.HALF_DOWN).toDouble()) {
+                    3.1415926536 -> return "floats.FL_PIVAL"
+                    1.4142135624 -> return "floats.FL_SQRTWO"
+                    0.7071067812 -> return "floats.FL_SQRHLF"
+                    0.6931471806 -> return "floats.FL_LOG2"
+                    else -> {}
+                }
+            }
+        }
+        return null
+    }
+
+    override fun importLibs(compilerOptions: CompilationOptions, importer: ModuleImporter, program: Program) {
+        if (compilerOptions.launcher == LauncherType.BASIC || compilerOptions.output == OutputType.PRG)
+            importer.importLibraryModule(program, "syslib")
+    }
+
+    override fun launchEmulator(programName: String) {
+        for(emulator in listOf("x64sc", "x64")) {
+            println("\nStarting C-64 emulator $emulator...")
+            val cmdline = listOf(emulator, "-silent", "-moncommands", "$programName.vice-mon-list",
+                    "-autostartprgmode", "1", "-autostart-warp", "-autostart", programName + ".prg")
+            val processb = ProcessBuilder(cmdline).inheritIO()
+            val process: Process
+            try {
+                process=processb.start()
+            } catch(x: IOException) {
+                continue  // try the next emulator executable
+            }
+            process.waitFor()
+            break
+        }
+    }
+
+    override fun isRegularRAMaddress(address: Int): Boolean = address<0xa000 || address in 0xc000..0xcfff
+
+    override fun initializeZeropage(compilerOptions: CompilationOptions) {
+        zeropage = C64Zeropage(compilerOptions)
+    }
 
     // 6502 opcodes (including aliases and illegal opcodes), these cannot be used as variable or label names
     override val opcodeNames = setOf("adc", "ahx", "alr", "anc", "and", "ane", "arr", "asl", "asr", "axs", "bcc", "bcs",
@@ -45,20 +107,12 @@ object C64MachineDefinition: IMachineDefinition {
             "sta", "stx", "sty", "tas", "tax", "tay", "tsx", "txa", "txs", "tya", "xaa")
 
 
-    class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
+    internal class C64Zeropage(options: CompilationOptions) : Zeropage(options) {
 
-        companion object {
-            const val SCRATCH_B1 = 0x02
-            const val SCRATCH_REG = 0x03    // temp storage for a register
-            const val SCRATCH_REG_X = 0xfa    // temp storage for register X (the evaluation stack pointer)
-            const val SCRATCH_W1 = 0xfb     // $fb+$fc
-            const val SCRATCH_W2 = 0xfd     // $fd+$fe
-        }
-
-        override val exitProgramStrategy: ExitProgramStrategy = when (options.zeropage) {
-            ZeropageType.BASICSAFE, ZeropageType.DONTUSE -> ExitProgramStrategy.CLEAN_EXIT
-            ZeropageType.FLOATSAFE, ZeropageType.KERNALSAFE, ZeropageType.FULL -> ExitProgramStrategy.SYSTEM_RESET
-        }
+        override val SCRATCH_B1 = 0x02      // temp storage for a single byte
+        override val SCRATCH_REG = 0x03     // temp storage for a register, must be B1+1
+        override val SCRATCH_W1 = 0xfb      // temp storage 1 for a word  $fb+$fc
+        override val SCRATCH_W2 = 0xfd      // temp storage 2 for a word  $fb+$fc
 
 
         init {
@@ -68,12 +122,14 @@ object C64MachineDefinition: IMachineDefinition {
             if (options.zeropage == ZeropageType.FULL) {
                 free.addAll(0x04..0xf9)
                 free.add(0xff)
-                free.removeAll(listOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_REG_X, SCRATCH_W1, SCRATCH_W1 + 1, SCRATCH_W2, SCRATCH_W2 + 1))
+                free.removeAll(listOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_W1, SCRATCH_W1 + 1, SCRATCH_W2, SCRATCH_W2 + 1))
                 free.removeAll(listOf(0xa0, 0xa1, 0xa2, 0x91, 0xc0, 0xc5, 0xcb, 0xf5, 0xf6))        // these are updated by IRQ
             } else {
                 if (options.zeropage == ZeropageType.KERNALSAFE || options.zeropage == ZeropageType.FLOATSAFE) {
-                    free.addAll(listOf(0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
-                            0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21,
+                    free.addAll(listOf(
+                            0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
+                            0x16, 0x17, 0x18, 0x19, 0x1a,
+                            0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21,
                             0x22, 0x23, 0x24, 0x25,
                             0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46,
                             0x47, 0x48, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x51, 0x52, 0x53,
@@ -90,38 +146,36 @@ object C64MachineDefinition: IMachineDefinition {
                 if (options.zeropage == ZeropageType.FLOATSAFE) {
                     // remove the zero page locations used for floating point operations from the free list
                     free.removeAll(listOf(
-                            0x12, 0x26, 0x27, 0x28, 0x29, 0x2a,
+                            0x10, 0x11, 0x12, 0x26, 0x27, 0x28, 0x29, 0x2a,
                             0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
                             0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
                             0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72,
-                            0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0xf
+                            0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0xff
                     ))
                 }
 
                 if(options.zeropage!=ZeropageType.DONTUSE) {
-                    // add the other free Zp addresses,
-                    // these are valid for the C-64 (when no RS232 I/O is performed) but to keep BASIC running fully:
+                    // 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,
-                            0x94, 0x95, 0xa7, 0xa8, 0xa9, 0xaa,
-                            0xb5, 0xb6, 0xf7, 0xf8, 0xf9))
+                            0x92, 0x96, 0x9b, 0x9c, 0x9e, 0x9f, 0xa5, 0xa6,
+                            0xb0, 0xb1, 0xbe, 0xbf, 0xf9))
                 } else {
                     // don't use the zeropage at all
                     free.clear()
                 }
             }
-            assert(SCRATCH_B1 !in free)
-            assert(SCRATCH_REG !in free)
-            assert(SCRATCH_REG_X !in free)
-            assert(SCRATCH_W1 !in free)
-            assert(SCRATCH_W2 !in free)
+            require(SCRATCH_B1 !in free)
+            require(SCRATCH_REG !in free)
+            require(SCRATCH_W1 !in free)
+            require(SCRATCH_W2 !in free)
 
             for (reserved in options.zpReserved)
                 reserve(reserved)
         }
     }
 
-
-    data class Mflpt5(val b0: Short, val b1: Short, val b2: Short, val b3: Short, val b4: Short) {
+    internal data class Mflpt5(val b0: Short, val b1: Short, val b2: Short, val b3: Short, val b4: Short): IMachineFloat {
 
         companion object {
             val zero = Mflpt5(0, 0, 0, 0, 0)
@@ -168,7 +222,7 @@ object C64MachineDefinition: IMachineDefinition {
             }
         }
 
-        fun toDouble(): Double {
+        override fun toDouble(): Double {
             if (this == zero) return 0.0
             val exp = b0 - 128
             val sign = (b1.toInt() and 0x80) > 0
@@ -176,91 +230,14 @@ object C64MachineDefinition: IMachineDefinition {
             val result = number.toDouble() * (2.0).pow(exp) / 0x100000000
             return if (sign) -result else result
         }
-    }
 
-    object Charset {
-        private val normalImg = ImageIO.read(javaClass.getResource("/charset/c64/charset-normal.png"))
-        private val shiftedImg = ImageIO.read(javaClass.getResource("/charset/c64/charset-shifted.png"))
-
-        private fun scanChars(img: BufferedImage): Array<BufferedImage> {
-
-            val transparent = BufferedImage(img.width, img.height, BufferedImage.TYPE_INT_ARGB)
-            transparent.createGraphics().drawImage(img, 0, 0, null)
-
-            val black = Color(0, 0, 0).rgb
-            val nopixel = Color(0, 0, 0, 0).rgb
-            for (y in 0 until transparent.height) {
-                for (x in 0 until transparent.width) {
-                    val col = transparent.getRGB(x, y)
-                    if (col == black)
-                        transparent.setRGB(x, y, nopixel)
-                }
-            }
-
-            val numColumns = transparent.width / 8
-            val charImages = (0..255).map {
-                val charX = it % numColumns
-                val charY = it / numColumns
-                transparent.getSubimage(charX * 8, charY * 8, 8, 8)
-            }
-            return charImages.toTypedArray()
+        override fun makeFloatFillAsm(): String {
+            val b0 = "$" + b0.toString(16).padStart(2, '0')
+            val b1 = "$" + b1.toString(16).padStart(2, '0')
+            val b2 = "$" + b2.toString(16).padStart(2, '0')
+            val b3 = "$" + b3.toString(16).padStart(2, '0')
+            val b4 = "$" + b4.toString(16).padStart(2, '0')
+            return "$b0, $b1, $b2, $b3, $b4"
         }
-
-        val normalChars = scanChars(normalImg)
-        val shiftedChars = scanChars(shiftedImg)
-
-        private val coloredNormalChars = mutableMapOf<Short, Array<BufferedImage>>()
-
-        fun getColoredChar(screenCode: Short, color: Short): BufferedImage {
-            val colorIdx = (color % colorPalette.size).toShort()
-            val chars = coloredNormalChars[colorIdx]
-            if (chars != null)
-                return chars[screenCode.toInt()]
-
-            val coloredChars = mutableListOf<BufferedImage>()
-            val transparent = Color(0, 0, 0, 0).rgb
-            val rgb = colorPalette[colorIdx.toInt()].rgb
-            for (c in normalChars) {
-                val colored = c.copy()
-                for (y in 0 until colored.height)
-                    for (x in 0 until colored.width) {
-                        if (colored.getRGB(x, y) != transparent) {
-                            colored.setRGB(x, y, rgb)
-                        }
-                    }
-                coloredChars.add(colored)
-            }
-            coloredNormalChars[colorIdx] = coloredChars.toTypedArray()
-            return coloredNormalChars.getValue(colorIdx)[screenCode.toInt()]
-        }
-
     }
-
-    private fun BufferedImage.copy(): BufferedImage {
-        val bcopy = BufferedImage(this.width, this.height, this.type)
-        val g = bcopy.graphics
-        g.drawImage(this, 0, 0, null)
-        g.dispose()
-        return bcopy
-    }
-
-    val colorPalette = listOf(         // this is Pepto's Commodore-64 palette  http://www.pepto.de/projects/colorvic/
-            Color(0x000000),  // 0 = black
-            Color(0xFFFFFF),  // 1 = white
-            Color(0x813338),  // 2 = red
-            Color(0x75cec8),  // 3 = cyan
-            Color(0x8e3c97),  // 4 = purple
-            Color(0x56ac4d),  // 5 = green
-            Color(0x2e2c9b),  // 6 = blue
-            Color(0xedf171),  // 7 = yellow
-            Color(0x8e5029),  // 8 = orange
-            Color(0x553800),  // 9 = brown
-            Color(0xc46c71),  // 10 = light red
-            Color(0x4a4a4a),  // 11 = dark grey
-            Color(0x7b7b7b),  // 12 = medium grey
-            Color(0xa9ff9f),  // 13 = light green
-            Color(0x706deb),  // 14 = light blue
-            Color(0xb2b2b2)   // 15 = light grey
-    )
-
 }

compiler/src/prog8/compiler/target/c64/Petscii.kt

@@ -1054,11 +1054,16 @@ object Petscii {
         val lookup = if(lowercase) encodingPetsciiLowercase else encodingPetsciiUppercase
         return text.map {
             val petscii = lookup[it]
-            petscii?.toShort() ?: if(it=='\u0000')
-                0.toShort()
-            else {
-                val case = if (lowercase) "lower" else "upper"
-                throw CharConversionException("no ${case}case Petscii character for '$it' (${it.toShort()})")
+            petscii?.toShort() ?: when (it) {
+                '\u0000' -> 0.toShort()
+                in '\u8000'..'\u80ff' -> {
+                    // special case: take the lower 8 bit hex value directly
+                    (it.toInt() - 0x8000).toShort()
+                }
+                else -> {
+                    val case = if (lowercase) "lower" else "upper"
+                    throw CharConversionException("no ${case}case Petscii character for '$it' (${it.toShort()})")
+                }
             }
         }
     }
@@ -1072,11 +1077,16 @@ object Petscii {
         val lookup = if(lowercase) encodingScreencodeLowercase else encodingScreencodeUppercase
         return text.map{
             val screencode = lookup[it]
-            screencode?.toShort() ?: if(it=='\u0000')
-                0.toShort()
-            else {
-                val case = if (lowercase) "lower" else "upper"
-                throw CharConversionException("no ${case}Screencode character for '$it' (${it.toShort()})")
+            screencode?.toShort() ?: when (it) {
+                '\u0000' -> 0.toShort()
+                in '\u8000'..'\u80ff' -> {
+                    // special case: take the lower 8 bit hex value directly
+                    (it.toInt() - 0x8000).toShort()
+                }
+                else -> {
+                    val case = if (lowercase) "lower" else "upper"
+                    throw CharConversionException("no ${case}Screencode character for '$it' (${it.toShort()})")
+                }
             }
         }
     }

compiler/src/prog8/compiler/target/c64/codegen/AsmOptimizer.kt

@@ -1,8 +1,5 @@
 package prog8.compiler.target.c64.codegen
 
-import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_HEX
-import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_PLUS1_HEX
-
 
 // note: see https://wiki.nesdev.com/w/index.php/6502_assembly_optimisations
 
@@ -13,43 +10,45 @@ fun optimizeAssembly(lines: MutableList<String>): Int {
 
     var linesByFour = getLinesBy(lines, 4)
 
-    var removeLines = optimizeUselessStackByteWrites(linesByFour)
-    if(removeLines.isNotEmpty()) {
-        for (i in removeLines.reversed())
-            lines.removeAt(i)
+    var mods = optimizeUselessStackByteWrites(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
         linesByFour = getLinesBy(lines, 4)
         numberOfOptimizations++
     }
 
-    removeLines = optimizeIncDec(linesByFour)
-    if(removeLines.isNotEmpty()) {
-        for (i in removeLines.reversed())
-            lines.removeAt(i)
+    mods = optimizeIncDec(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
         linesByFour = getLinesBy(lines, 4)
         numberOfOptimizations++
     }
 
-    removeLines = optimizeCmpSequence(linesByFour)
-    if(removeLines.isNotEmpty()) {
-        for (i in removeLines.reversed())
-            lines.removeAt(i)
+    mods = optimizeCmpSequence(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
         linesByFour = getLinesBy(lines, 4)
         numberOfOptimizations++
     }
 
-    removeLines = optimizeStoreLoadSame(linesByFour)
-    if(removeLines.isNotEmpty()) {
-        for (i in removeLines.reversed())
-            lines.removeAt(i)
+    mods = optimizeStoreLoadSame(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
+        linesByFour = getLinesBy(lines, 4)
+        numberOfOptimizations++
+    }
+
+    mods= optimizeJsrRts(linesByFour)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
         linesByFour = getLinesBy(lines, 4)
         numberOfOptimizations++
     }
 
     var linesByFourteen = getLinesBy(lines, 14)
-    removeLines = optimizeSameAssignments(linesByFourteen)
-    if(removeLines.isNotEmpty()) {
-        for (i in removeLines.reversed())
-            lines.removeAt(i)
+    mods = optimizeSameAssignments(linesByFourteen)
+    if(mods.isNotEmpty()) {
+        apply(mods, lines)
         linesByFourteen = getLinesBy(lines, 14)
         numberOfOptimizations++
     }
@@ -59,7 +58,22 @@ fun optimizeAssembly(lines: MutableList<String>): Int {
     return numberOfOptimizations
 }
 
-fun optimizeCmpSequence(linesByFour: List<List<IndexedValue<String>>>): List<Int> {
+private class Modification(val lineIndex: Int, val remove: Boolean, val replacement: String?)
+
+private fun apply(modifications: List<Modification>, lines: MutableList<String>) {
+    for (modification in modifications.sortedBy { it.lineIndex }.reversed()) {
+        if(modification.remove)
+            lines.removeAt(modification.lineIndex)
+        else
+            lines[modification.lineIndex] = modification.replacement!!
+    }
+}
+
+private fun getLinesBy(lines: MutableList<String>, windowSize: Int) =
+// all lines (that aren't empty or comments) in sliding windows of certain size
+        lines.withIndex().filter { it.value.isNotBlank() && !it.value.trimStart().startsWith(';') }.windowed(windowSize, partialWindows = false)
+
+private fun optimizeCmpSequence(linesByFour: List<List<IndexedValue<String>>>): List<Modification> {
     // the when statement (on bytes) generates a sequence of:
     //	 lda $ce01,x
     //	 cmp #$20
@@ -68,42 +82,42 @@ fun optimizeCmpSequence(linesByFour: List<List<IndexedValue<String>>>): List<Int
     //	 cmp #$21
     //	 beq  check_prog8_s73choice_33
     // the repeated lda can be removed
-    val removeLines = mutableListOf<Int>()
+    val mods = mutableListOf<Modification>()
     for(lines in linesByFour) {
-        if(lines[0].value.trim()=="lda  $ESTACK_LO_PLUS1_HEX,x" &&
+        if(lines[0].value.trim()=="lda  P8ESTACK_LO+1,x" &&
                 lines[1].value.trim().startsWith("cmp ") &&
                 lines[2].value.trim().startsWith("beq ") &&
-                lines[3].value.trim()=="lda  $ESTACK_LO_PLUS1_HEX,x") {
-            removeLines.add(lines[3].index) // remove the second lda
+                lines[3].value.trim()=="lda  P8ESTACK_LO+1,x") {
+            mods.add(Modification(lines[3].index, true, null)) // remove the second lda
         }
     }
-    return removeLines
+    return mods
 }
 
-fun optimizeUselessStackByteWrites(linesByFour: List<List<IndexedValue<String>>>): List<Int> {
+private fun optimizeUselessStackByteWrites(linesByFour: List<List<IndexedValue<String>>>): List<Modification> {
     // sta on stack, dex, inx, lda from stack -> eliminate this useless stack byte write
     // this is a lot harder for word values because the instruction sequence varies.
-    val removeLines = mutableListOf<Int>()
+    val mods = mutableListOf<Modification>()
     for(lines in linesByFour) {
-        if(lines[0].value.trim()=="sta  $ESTACK_LO_HEX,x" &&
+        if(lines[0].value.trim()=="sta  P8ESTACK_LO,x" &&
                 lines[1].value.trim()=="dex" &&
                 lines[2].value.trim()=="inx" &&
-                lines[3].value.trim()=="lda  $ESTACK_LO_HEX,x") {
-            removeLines.add(lines[1].index)
-            removeLines.add(lines[2].index)
-            removeLines.add(lines[3].index)
+                lines[3].value.trim()=="lda  P8ESTACK_LO,x") {
+            mods.add(Modification(lines[1].index, true, null))
+            mods.add(Modification(lines[2].index, true, null))
+            mods.add(Modification(lines[3].index, true, null))
         }
     }
-    return removeLines
+    return mods
 }
 
-fun optimizeSameAssignments(linesByFourteen: List<List<IndexedValue<String>>>): List<Int> {
+private fun optimizeSameAssignments(linesByFourteen: List<List<IndexedValue<String>>>): List<Modification> {
 
     // optimize sequential assignments of the isSameAs value to various targets (bytes, words, floats)
     // the float one is the one that requires 2*7=14 lines of code to check...
     // @todo a better place to do this is in the Compiler instead and transform the Ast, or the AsmGen, and never even create the inefficient asm in the first place...
 
-    val removeLines = mutableListOf<Int>()
+    val mods = mutableListOf<Modification>()
     for (pair in linesByFourteen) {
         val first = pair[0].value.trimStart()
         val second = pair[1].value.trimStart()
@@ -122,8 +136,8 @@ fun optimizeSameAssignments(linesByFourteen: List<List<IndexedValue<String>>>):
             val fourthvalue = sixth.substring(4)
             if(firstvalue==thirdvalue && secondvalue==fourthvalue) {
                 // lda/ldy   sta/sty   twice the isSameAs word -->  remove second lda/ldy pair (fifth and sixth lines)
-                removeLines.add(pair[4].index)
-                removeLines.add(pair[5].index)
+                mods.add(Modification(pair[4].index, true, null))
+                mods.add(Modification(pair[5].index, true, null))
             }
         }
 
@@ -132,12 +146,13 @@ fun optimizeSameAssignments(linesByFourteen: List<List<IndexedValue<String>>>):
             val secondvalue = third.substring(4)
             if(firstvalue==secondvalue) {
                 // lda value / sta ? / lda isSameAs-value / sta ?  -> remove second lda (third line)
-                removeLines.add(pair[2].index)
+                mods.add(Modification(pair[2].index, true, null))
             }
         }
 
         if(first.startsWith("lda") && second.startsWith("ldy") && third.startsWith("sta") && fourth.startsWith("sty") &&
-                fifth.startsWith("lda") && sixth.startsWith("ldy") && seventh.startsWith("jsr  c64flt.copy_float")) {
+                fifth.startsWith("lda") && sixth.startsWith("ldy") &&
+                (seventh.startsWith("jsr  floats.copy_float") || seventh.startsWith("jsr  cx16flt.copy_float"))) {
 
             val nineth = pair[8].value.trimStart()
             val tenth = pair[9].value.trimStart()
@@ -147,28 +162,26 @@ fun optimizeSameAssignments(linesByFourteen: List<List<IndexedValue<String>>>):
             val fourteenth = pair[13].value.trimStart()
 
             if(eighth.startsWith("lda") && nineth.startsWith("ldy") && tenth.startsWith("sta") && eleventh.startsWith("sty") &&
-                    twelveth.startsWith("lda") && thirteenth.startsWith("ldy") && fourteenth.startsWith("jsr  c64flt.copy_float")) {
+                    twelveth.startsWith("lda") && thirteenth.startsWith("ldy") &&
+                    (fourteenth.startsWith("jsr  floats.copy_float") || fourteenth.startsWith("jsr  cx16flt.copy_float"))) {
 
                 if(first.substring(4) == eighth.substring(4) && second.substring(4)==nineth.substring(4)) {
                     // identical float init
-                    removeLines.add(pair[7].index)
-                    removeLines.add(pair[8].index)
-                    removeLines.add(pair[9].index)
-                    removeLines.add(pair[10].index)
+                    mods.add(Modification(pair[7].index, true, null))
+                    mods.add(Modification(pair[8].index, true, null))
+                    mods.add(Modification(pair[9].index, true, null))
+                    mods.add(Modification(pair[10].index, true, null))
                 }
             }
         }
     }
-    return removeLines
+    return mods
 }
 
-private fun getLinesBy(lines: MutableList<String>, windowSize: Int) =
-// all lines (that aren't empty or comments) in sliding windows of certain size
-        lines.withIndex().filter { it.value.isNotBlank() && !it.value.trimStart().startsWith(';') }.windowed(windowSize, partialWindows = false)
-
-private fun optimizeStoreLoadSame(linesByFour: List<List<IndexedValue<String>>>): List<Int> {
+private fun optimizeStoreLoadSame(linesByFour: List<List<IndexedValue<String>>>): List<Modification> {
     // sta X + lda X,  sty X + ldy X,   stx X + ldx X  -> the second instruction can be eliminated
-    val removeLines = mutableListOf<Int>()
+    // TODO this is not true if X is not a regular RAM memory address (but instead mapped I/O or ROM)
+    val mods = mutableListOf<Modification>()
     for (pair in linesByFour) {
         val first = pair[0].value.trimStart()
         val second = pair[1].value.trimStart()
@@ -183,29 +196,43 @@ private fun optimizeStoreLoadSame(linesByFour: List<List<IndexedValue<String>>>)
                 (first.startsWith("sty ") && second.startsWith("ldy ")) ||
                 (first.startsWith("stx ") && second.startsWith("ldx "))
         ) {
-            val firstLoc = first.substring(4)
-            val secondLoc = second.substring(4)
+            val firstLoc = first.substring(4).trimStart()
+            val secondLoc = second.substring(4).trimStart()
             if (firstLoc == secondLoc) {
-                removeLines.add(pair[1].index)
+                mods.add(Modification(pair[1].index, true, null))
             }
         }
     }
-    return removeLines
+    return mods
 }
 
-private fun optimizeIncDec(linesByTwo: List<List<IndexedValue<String>>>): List<Int> {
+private fun optimizeIncDec(linesByFour: List<List<IndexedValue<String>>>): List<Modification> {
     // sometimes, iny+dey / inx+dex / dey+iny / dex+inx sequences are generated, these can be eliminated.
-    val removeLines = mutableListOf<Int>()
-    for (pair in linesByTwo) {
+    val mods = mutableListOf<Modification>()
+    for (pair in linesByFour) {
         val first = pair[0].value
         val second = pair[1].value
         if ((" iny" in first || "\tiny" in first) && (" dey" in second || "\tdey" in second)
                 || (" inx" in first || "\tinx" in first) && (" dex" in second || "\tdex" in second)
                 || (" dey" in first || "\tdey" in first) && (" iny" in second || "\tiny" in second)
                 || (" dex" in first || "\tdex" in first) && (" inx" in second || "\tinx" in second)) {
-            removeLines.add(pair[0].index)
-            removeLines.add(pair[1].index)
+            mods.add(Modification(pair[0].index, true, null))
+            mods.add(Modification(pair[1].index, true, null))
         }
     }
-    return removeLines
+    return mods
+}
+
+private fun optimizeJsrRts(linesByFour: List<List<IndexedValue<String>>>): List<Modification> {
+    // jsr Sub + rts -> jmp Sub
+    val mods = mutableListOf<Modification>()
+    for (pair in linesByFour) {
+        val first = pair[0].value
+        val second = pair[1].value
+        if ((" jsr" in first || "\tjsr" in first ) && (" rts" in second || "\trts" in second)) {
+            mods += Modification(pair[0].index, false, pair[0].value.replace("jsr", "jmp"))
+            mods += Modification(pair[1].index, true, null)
+        }
+    }
+    return mods
 }

compiler/src/prog8/compiler/target/c64/codegen/AssignmentAsmGen.kt

@@ -1,750 +0,0 @@
-package prog8.compiler.target.c64.codegen
-
-import prog8.ast.Program
-import prog8.ast.base.*
-import prog8.ast.expressions.*
-import prog8.ast.statements.AssignTarget
-import prog8.ast.statements.Assignment
-import prog8.ast.statements.DirectMemoryWrite
-import prog8.ast.statements.VarDecl
-import prog8.compiler.toHex
-import prog8.compiler.AssemblyError
-import prog8.compiler.target.c64.C64MachineDefinition
-import prog8.compiler.target.c64.C64MachineDefinition.C64Zeropage
-import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_HI_HEX
-import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_HEX
-
-
-internal class AssignmentAsmGen(private val program: Program, private val asmgen: AsmGen) {
-
-    internal fun translate(assign: Assignment) {
-        if(assign.aug_op!=null)
-            throw AssemblyError("aug-op assignments should have been transformed to normal ones")
-
-        when(assign.value) {
-            is NumericLiteralValue -> {
-                val numVal = assign.value as NumericLiteralValue
-                when(numVal.type) {
-                    DataType.UBYTE, DataType.BYTE -> assignFromByteConstant(assign.target, numVal.number.toShort())
-                    DataType.UWORD, DataType.WORD -> assignFromWordConstant(assign.target, numVal.number.toInt())
-                    DataType.FLOAT -> assignFromFloatConstant(assign.target, numVal.number.toDouble())
-                    else -> throw AssemblyError("weird numval type")
-                }
-            }
-            is RegisterExpr -> {
-                assignFromRegister(assign.target, (assign.value as RegisterExpr).register)
-            }
-            is IdentifierReference -> {
-                val type = assign.target.inferType(program, assign).typeOrElse(DataType.STRUCT)
-                when(type) {
-                    DataType.UBYTE, DataType.BYTE -> assignFromByteVariable(assign.target, assign.value as IdentifierReference)
-                    DataType.UWORD, DataType.WORD -> assignFromWordVariable(assign.target, assign.value as IdentifierReference)
-                    DataType.FLOAT -> assignFromFloatVariable(assign.target, assign.value as IdentifierReference)
-                    else -> throw AssemblyError("unsupported assignment target type $type")
-                }
-            }
-            is AddressOf -> {
-                val identifier = (assign.value as AddressOf).identifier
-                assignFromAddressOf(assign.target, identifier)
-            }
-            is DirectMemoryRead -> {
-                val read = (assign.value as DirectMemoryRead)
-                when(read.addressExpression) {
-                    is NumericLiteralValue -> {
-                        val address = (read.addressExpression as NumericLiteralValue).number.toInt()
-                        assignFromMemoryByte(assign.target, address, null)
-                    }
-                    is IdentifierReference -> {
-                        assignFromMemoryByte(assign.target, null, read.addressExpression as IdentifierReference)
-                    }
-                    else -> {
-                        asmgen.translateExpression(read.addressExpression)
-                        TODO("read memory byte from result and put that in ${assign.target}")
-                    }
-                }
-            }
-            is PrefixExpression -> {
-                // TODO optimize common cases
-                asmgen.translateExpression(assign.value as PrefixExpression)
-                assignFromEvalResult(assign.target)
-            }
-            is BinaryExpression -> {
-                // TODO optimize common cases
-                asmgen.translateExpression(assign.value as BinaryExpression)
-                assignFromEvalResult(assign.target)
-            }
-            is ArrayIndexedExpression -> {
-                // TODO optimize common cases
-                val arrayExpr = assign.value as ArrayIndexedExpression
-                val arrayDt = arrayExpr.identifier.targetVarDecl(program.namespace)!!.datatype
-                val index = arrayExpr.arrayspec.index
-                if(index is NumericLiteralValue) {
-                    // constant array index value
-                    val arrayVarName = asmgen.asmIdentifierName(arrayExpr.identifier)
-                    val indexValue = index.number.toInt() * ArrayElementTypes.getValue(arrayDt).memorySize()
-                    when (arrayDt) {
-                        DataType.STR, DataType.ARRAY_UB, DataType.ARRAY_B ->
-                            asmgen.out("  lda  $arrayVarName+$indexValue |  sta  $ESTACK_LO_HEX,x |  dex")
-                        DataType.ARRAY_UW, DataType.ARRAY_W ->
-                            asmgen.out("  lda  $arrayVarName+$indexValue |  sta  $ESTACK_LO_HEX,x |  lda  $arrayVarName+$indexValue+1 |  sta  $ESTACK_HI_HEX,x | dex")
-                        DataType.ARRAY_F ->
-                            asmgen.out("  lda  #<$arrayVarName+$indexValue |  ldy  #>$arrayVarName+$indexValue |  jsr  c64flt.push_float")
-                        else ->
-                            throw AssemblyError("weird array type")
-                    }
-                } else {
-                    asmgen.translateArrayIndexIntoA(arrayExpr)
-                    asmgen.readAndPushArrayvalueWithIndexA(arrayDt, arrayExpr.identifier)
-                }
-                assignFromEvalResult(assign.target)
-            }
-            is TypecastExpression -> {
-                val cast = assign.value as TypecastExpression
-                val sourceType = cast.expression.inferType(program)
-                val targetType = assign.target.inferType(program, assign)
-                if(sourceType.isKnown && targetType.isKnown &&
-                        (sourceType.typeOrElse(DataType.STRUCT) in ByteDatatypes && targetType.typeOrElse(DataType.STRUCT) in ByteDatatypes) ||
-                        (sourceType.typeOrElse(DataType.STRUCT) in WordDatatypes && targetType.typeOrElse(DataType.STRUCT) in WordDatatypes)) {
-                    // no need for a type cast
-                    assign.value = cast.expression
-                    translate(assign)
-                } else {
-                    asmgen.translateExpression(assign.value as TypecastExpression)
-                    assignFromEvalResult(assign.target)
-                }
-            }
-            is FunctionCall -> {
-                asmgen.translateExpression(assign.value as FunctionCall)
-                assignFromEvalResult(assign.target)
-            }
-            is ArrayLiteralValue, is StringLiteralValue -> TODO("string/array/struct assignment?")
-            is StructLiteralValue -> throw AssemblyError("struct literal value assignment should have been flattened")
-            is RangeExpr -> throw AssemblyError("range expression should have been changed into array values")
-        }
-    }
-
-    internal fun assignFromEvalResult(target: AssignTarget) {
-        val targetIdent = target.identifier
-        when {
-            target.register!=null -> {
-                if(target.register== Register.X)
-                    throw AssemblyError("can't pop into X register - use variable instead")
-                asmgen.out(" inx | ld${target.register.name.toLowerCase()}  $ESTACK_LO_HEX,x ")
-            }
-            targetIdent!=null -> {
-                val targetName = asmgen.asmIdentifierName(targetIdent)
-                val targetDt = targetIdent.inferType(program).typeOrElse(DataType.STRUCT)
-                when(targetDt) {
-                    DataType.UBYTE, DataType.BYTE -> {
-                        asmgen.out(" inx | lda  $ESTACK_LO_HEX,x  | sta  $targetName")
-                    }
-                    DataType.UWORD, DataType.WORD -> {
-                        asmgen.out("""
-                            inx
-                            lda  $ESTACK_LO_HEX,x
-                            sta  $targetName
-                            lda  $ESTACK_HI_HEX,x
-                            sta  $targetName+1
-                        """)
-                    }
-                    DataType.FLOAT -> {
-                        asmgen.out("""
-                            lda  #<$targetName
-                            ldy  #>$targetName
-                            jsr  c64flt.pop_float
-                        """)
-                    }
-                    else -> throw AssemblyError("weird target variable type $targetDt")
-                }
-            }
-            target.memoryAddress!=null -> {
-                asmgen.out("  inx  | ldy  $ESTACK_LO_HEX,x")
-                storeRegisterInMemoryAddress(Register.Y, target.memoryAddress)
-            }
-            target.arrayindexed!=null -> {
-                val arrayDt = target.arrayindexed!!.identifier.targetVarDecl(program.namespace)!!.datatype
-                val arrayVarName = asmgen.asmIdentifierName(target.arrayindexed!!.identifier)
-                asmgen.translateExpression(target.arrayindexed!!.arrayspec.index)
-                asmgen.out("  inx |  lda  $ESTACK_LO_HEX,x")
-                popAndWriteArrayvalueWithIndexA(arrayDt, arrayVarName)
-            }
-            else -> throw AssemblyError("weird assignment target $target")
-        }
-    }
-
-    internal fun assignFromAddressOf(target: AssignTarget, name: IdentifierReference) {
-        val targetIdent = target.identifier
-        val targetArrayIdx = target.arrayindexed
-        val struct = name.memberOfStruct(program.namespace)
-        val sourceName = if(struct!=null) {
-            // take the address of the first struct member instead
-            val decl = name.targetVarDecl(program.namespace)!!
-            val firstStructMember = struct.nameOfFirstMember()
-            // find the flattened var that belongs to this first struct member
-            val firstVarName = listOf(decl.name, firstStructMember)
-            val firstVar = name.definingScope().lookup(firstVarName, name) as VarDecl
-            firstVar.name
-        } else {
-            asmgen.fixNameSymbols(name.nameInSource.joinToString ("."))
-        }
-
-        when {
-            targetIdent!=null -> {
-                val targetName = asmgen.asmIdentifierName(targetIdent)
-                asmgen.out("""
-                        lda  #<$sourceName
-                        ldy  #>$sourceName
-                        sta  $targetName
-                        sty  $targetName+1
-                    """)
-            }
-            target.memoryAddress!=null -> {
-                TODO("assign address $sourceName to memory word $target")
-            }
-            targetArrayIdx!=null -> {
-                val index = targetArrayIdx.arrayspec.index
-                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
-                TODO("assign address $sourceName to array $targetName [ $index ]")
-            }
-            else -> TODO("assign address $sourceName to $target")
-        }
-    }
-
-    internal fun assignFromWordVariable(target: AssignTarget, variable: IdentifierReference) {
-        val sourceName = asmgen.asmIdentifierName(variable)
-        val targetIdent = target.identifier
-        val targetArrayIdx = target.arrayindexed
-        when {
-            targetIdent!=null -> {
-                val targetName = asmgen.asmIdentifierName(targetIdent)
-                asmgen.out("""
-                    lda  $sourceName
-                    ldy  $sourceName+1
-                    sta  $targetName
-                    sty  $targetName+1
-                """)
-            }
-            target.memoryAddress!=null -> {
-                TODO("assign wordvar $sourceName to memory ${target.memoryAddress}")
-            }
-            targetArrayIdx!=null -> {
-                val index = targetArrayIdx.arrayspec.index
-                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
-                asmgen.out("  lda  $sourceName |  sta  $ESTACK_LO_HEX,x |  lda  $sourceName+1 |  sta  $ESTACK_HI_HEX,x |  dex")
-                asmgen.translateExpression(index)
-                asmgen.out("  inx |  lda  $ESTACK_LO_HEX,x")
-                val arrayDt = targetArrayIdx.identifier.inferType(program).typeOrElse(DataType.STRUCT)
-                popAndWriteArrayvalueWithIndexA(arrayDt, targetName)
-            }
-            else -> TODO("assign wordvar to $target")
-        }
-    }
-
-    internal fun assignFromFloatVariable(target: AssignTarget, variable: IdentifierReference) {
-        val sourceName = asmgen.asmIdentifierName(variable)
-        val targetIdent = target.identifier
-        val targetArrayIdx = target.arrayindexed
-        when {
-            targetIdent!=null -> {
-                val targetName = asmgen.asmIdentifierName(targetIdent)
-                asmgen.out("""
-                    lda  $sourceName
-                    sta  $targetName
-                    lda  $sourceName+1
-                    sta  $targetName+1
-                    lda  $sourceName+2
-                    sta  $targetName+2
-                    lda  $sourceName+3
-                    sta  $targetName+3
-                    lda  $sourceName+4
-                    sta  $targetName+4
-                """)
-            }
-            targetArrayIdx!=null -> {
-                val index = targetArrayIdx.arrayspec.index
-                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
-                asmgen.out("  lda  #<$sourceName |  ldy  #>$sourceName |  jsr  c64flt.push_float")
-                asmgen.translateExpression(index)
-                asmgen.out("  lda  #<$targetName |  ldy  #>$targetName |  jsr  c64flt.pop_float_to_indexed_var")
-            }
-            else -> TODO("assign floatvar to $target")
-        }
-    }
-
-    internal fun assignFromByteVariable(target: AssignTarget, variable: IdentifierReference) {
-        val sourceName = asmgen.asmIdentifierName(variable)
-        val targetIdent = target.identifier
-        val targetArrayIdx = target.arrayindexed
-        when {
-            target.register!=null -> {
-                asmgen.out("  ld${target.register.name.toLowerCase()}  $sourceName")
-            }
-            targetIdent!=null -> {
-                val targetName = asmgen.asmIdentifierName(targetIdent)
-                asmgen.out("""
-                    lda  $sourceName
-                    sta  $targetName
-                    """)
-            }
-            targetArrayIdx!=null -> {
-                val index = targetArrayIdx.arrayspec.index
-                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
-                val arrayDt = targetArrayIdx.identifier.inferType(program).typeOrElse(DataType.STRUCT)
-                asmgen.out("  lda  $sourceName |  sta  $ESTACK_LO_HEX,x |  dex")
-                asmgen.translateExpression(index)
-                asmgen.out("  inx |  lda  $ESTACK_LO_HEX,x")
-                popAndWriteArrayvalueWithIndexA(arrayDt, targetName)
-            }
-            target.memoryAddress != null -> {
-                val addressExpr = target.memoryAddress.addressExpression
-                val addressLv = addressExpr as? NumericLiteralValue
-                when {
-                    addressLv != null -> asmgen.out("  lda  $sourceName |  sta  ${addressLv.number.toHex()}")
-                    addressExpr is IdentifierReference -> {
-                        val targetName = asmgen.asmIdentifierName(addressExpr)
-                        asmgen.out("  lda  $sourceName |  sta  $targetName")
-                    }
-                    else -> {
-                        asmgen.translateExpression(addressExpr)
-                        asmgen.out("""
-     inx
-     lda  $ESTACK_LO_HEX,x
-     ldy  $ESTACK_HI_HEX,x
-     sta  (+) +1
-     sty  (+) +2
-     lda  $sourceName
-+    sta  ${65535.toHex()}      ; modified              
-                            """)
-                    }
-                }
-            }
-            else -> TODO("assign bytevar to $target")
-        }
-    }
-
-    internal fun assignFromRegister(target: AssignTarget, register: Register) {
-        val targetIdent = target.identifier
-        val targetArrayIdx = target.arrayindexed
-        when {
-            targetIdent!=null -> {
-                val targetName = asmgen.asmIdentifierName(targetIdent)
-                asmgen.out("  st${register.name.toLowerCase()}  $targetName")
-            }
-            target.register!=null -> {
-                when(register) {
-                    Register.A -> when(target.register) {
-                        Register.A -> {}
-                        Register.X -> asmgen.out("  tax")
-                        Register.Y -> asmgen.out("  tay")
-                    }
-                    Register.X -> when(target.register) {
-                        Register.A -> asmgen.out("  txa")
-                        Register.X -> {}
-                        Register.Y -> asmgen.out("  txy")
-                    }
-                    Register.Y -> when(target.register) {
-                        Register.A -> asmgen.out("  tya")
-                        Register.X -> asmgen.out("  tyx")
-                        Register.Y -> {}
-                    }
-                }
-            }
-            target.memoryAddress!=null -> {
-                storeRegisterInMemoryAddress(register, target.memoryAddress)
-            }
-            targetArrayIdx!=null -> {
-                val index = targetArrayIdx.arrayspec.index
-                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
-                when (index) {
-                    is NumericLiteralValue -> {
-                        val memindex = index.number.toInt()
-                        when(register) {
-                            Register.A -> asmgen.out("  sta  $targetName+$memindex")
-                            Register.X -> asmgen.out("  stx  $targetName+$memindex")
-                            Register.Y -> asmgen.out("  sty  $targetName+$memindex")
-                        }
-                    }
-                    is RegisterExpr -> {
-                        when(register) {
-                            Register.A -> asmgen.out("  sta  ${C64Zeropage.SCRATCH_B1}")
-                            Register.X -> asmgen.out("  stx  ${C64Zeropage.SCRATCH_B1}")
-                            Register.Y -> asmgen.out("  sty  ${C64Zeropage.SCRATCH_B1}")
-                        }
-                        when(index.register) {
-                            Register.A -> {}
-                            Register.X -> asmgen.out("  txa")
-                            Register.Y -> asmgen.out("  tya")
-                        }
-                        asmgen.out("""
-                            tay
-                            lda  ${C64Zeropage.SCRATCH_B1}
-                            sta  $targetName,y
-                            """)
-                    }
-                    is IdentifierReference -> {
-                        when(register) {
-                            Register.A -> asmgen.out("  sta  ${C64Zeropage.SCRATCH_B1}")
-                            Register.X -> asmgen.out("  stx  ${C64Zeropage.SCRATCH_B1}")
-                            Register.Y -> asmgen.out("  sty  ${C64Zeropage.SCRATCH_B1}")
-                        }
-                        asmgen.out("""
-                            lda  ${asmgen.asmIdentifierName(index)}
-                            tay
-                            lda  ${C64Zeropage.SCRATCH_B1}
-                            sta  $targetName,y
-                        """)
-                    }
-                    else -> {
-                        asmgen.saveRegister(register)
-                        asmgen.translateExpression(index)
-                        asmgen.restoreRegister(register)
-                        when(register) {
-                            Register.A -> asmgen.out("  sta  ${C64Zeropage.SCRATCH_B1}")
-                            Register.X -> asmgen.out("  stx  ${C64Zeropage.SCRATCH_B1}")
-                            Register.Y -> asmgen.out("  sty  ${C64Zeropage.SCRATCH_B1}")
-                        }
-                        asmgen.out("""
-                            inx
-                            lda  $ESTACK_LO_HEX,x
-                            tay
-                            lda  ${C64Zeropage.SCRATCH_B1}
-                            sta  $targetName,y  
-                        """)
-                    }
-                }
-            }
-            else -> TODO("assign register $register to $target")
-        }
-    }
-
-    private fun storeRegisterInMemoryAddress(register: Register, memoryAddress: DirectMemoryWrite) {
-        val addressExpr = memoryAddress.addressExpression
-        val addressLv = addressExpr as? NumericLiteralValue
-        val registerName = register.name.toLowerCase()
-        when {
-            addressLv != null -> asmgen.out("  st$registerName  ${addressLv.number.toHex()}")
-            addressExpr is IdentifierReference -> {
-                val targetName = asmgen.asmIdentifierName(addressExpr)
-                when(register) {
-                    Register.A -> asmgen.out("""
-                        ldy  $targetName
-                        sty  ${C64Zeropage.SCRATCH_W1}
-                        ldy  $targetName+1
-                        sty  ${C64Zeropage.SCRATCH_W1+1}
-                        ldy  #0
-                        sta  (${C64Zeropage.SCRATCH_W1}),y
-                        """)
-                    Register.X -> asmgen.out("""
-                        txa
-                        ldy  $targetName
-                        sty  ${C64Zeropage.SCRATCH_W1}
-                        ldy  $targetName+1
-                        sty  ${C64Zeropage.SCRATCH_W1+1}
-                        ldy  #0
-                        sta  (${C64Zeropage.SCRATCH_W1}),y
-                        """)
-                    Register.Y -> asmgen.out("""
-                        tya
-                        ldy  $targetName
-                        sty  ${C64Zeropage.SCRATCH_W1}
-                        ldy  $targetName+1
-                        sty  ${C64Zeropage.SCRATCH_W1+1}
-                        ldy  #0
-                        sta  (${C64Zeropage.SCRATCH_W1}),y
-                        """)
-                }
-            }
-            else -> {
-                asmgen.saveRegister(register)
-                asmgen.translateExpression(addressExpr)
-                asmgen.restoreRegister(register)
-                when (register) {
-                    Register.A -> asmgen.out("  tay")
-                    Register.X -> throw AssemblyError("can't use X register here")
-                    Register.Y -> {}
-                }
-                asmgen.out("""
-     inx
-     lda  $ESTACK_LO_HEX,x
-     sta  (+) +1
-     lda  $ESTACK_HI_HEX,x
-     sta  (+) +2
-+    sty  ${65535.toHex()}      ; modified              
-                            """)
-            }
-        }
-    }
-
-    internal fun assignFromWordConstant(target: AssignTarget, word: Int) {
-        val targetIdent = target.identifier
-        val targetArrayIdx = target.arrayindexed
-        when {
-            targetIdent!=null -> {
-                val targetName = asmgen.asmIdentifierName(targetIdent)
-                if(word ushr 8 == word and 255) {
-                    // lsb=msb
-                    asmgen.out("""
-                    lda  #${(word and 255).toHex()}
-                    sta  $targetName
-                    sta  $targetName+1
-                """)
-                } else {
-                    asmgen.out("""
-                    lda  #<${word.toHex()}
-                    ldy  #>${word.toHex()}
-                    sta  $targetName
-                    sty  $targetName+1
-                """)
-                }
-            }
-            target.memoryAddress!=null -> {
-                TODO("assign word $word to memory ${target.memoryAddress}")
-            }
-            targetArrayIdx!=null -> {
-                val index = targetArrayIdx.arrayspec.index
-                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
-                // TODO optimize common cases
-                asmgen.translateExpression(index)
-                asmgen.out("""
-                    inx
-                    lda  $ESTACK_LO_HEX,x
-                    asl  a
-                    tay
-                    lda  #<${word.toHex()}
-                    sta  $targetName,y
-                    lda  #>${word.toHex()}
-                    sta  $targetName+1,y
-                """)
-            }
-            else -> TODO("assign word $word to $target")
-        }
-    }
-
-    internal fun assignFromByteConstant(target: AssignTarget, byte: Short) {
-        val targetIdent = target.identifier
-        val targetArrayIdx = target.arrayindexed
-        when {
-            target.register!=null -> {
-                asmgen.out("  ld${target.register.name.toLowerCase()}  #${byte.toHex()}")
-            }
-            targetIdent!=null -> {
-                val targetName = asmgen.asmIdentifierName(targetIdent)
-                asmgen.out(" lda  #${byte.toHex()} |  sta  $targetName ")
-            }
-            target.memoryAddress!=null -> {
-                asmgen.out("  ldy  #${byte.toHex()}")
-                storeRegisterInMemoryAddress(Register.Y, target.memoryAddress)
-            }
-            targetArrayIdx!=null -> {
-                val index = targetArrayIdx.arrayspec.index
-                val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
-                // TODO optimize common cases
-                asmgen.translateExpression(index)
-                asmgen.out("""
-                    inx
-                    ldy  $ESTACK_LO_HEX,x
-                    lda  #${byte.toHex()}
-                    sta  $targetName,y
-                """)
-            }
-            else -> TODO("assign byte $byte to $target")
-        }
-    }
-
-    internal fun assignFromFloatConstant(target: AssignTarget, float: Double) {
-        val targetIdent = target.identifier
-        val targetArrayIdx = target.arrayindexed
-        if(float==0.0) {
-            // optimized case for float zero
-            when {
-                targetIdent != null -> {
-                    val targetName = asmgen.asmIdentifierName(targetIdent)
-                    asmgen.out("""
-                            lda  #0
-                            sta  $targetName
-                            sta  $targetName+1
-                            sta  $targetName+2
-                            sta  $targetName+3
-                            sta  $targetName+4
-                        """)
-                }
-                targetArrayIdx!=null -> {
-                    val index = targetArrayIdx.arrayspec.index
-                    val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
-                    if(index is NumericLiteralValue) {
-                        val indexValue = index.number.toInt() * C64MachineDefinition.FLOAT_MEM_SIZE
-                        asmgen.out("""
-                            lda  #0
-                            sta  $targetName+$indexValue
-                            sta  $targetName+$indexValue+1
-                            sta  $targetName+$indexValue+2
-                            sta  $targetName+$indexValue+3
-                            sta  $targetName+$indexValue+4
-                        """)
-                    } else {
-                        asmgen.translateExpression(index)
-                        asmgen.out("""
-                        inx
-                        lda  $ESTACK_LO_HEX,x
-                        asl  a
-                        asl  a
-                        clc
-                        adc  $ESTACK_LO_HEX,x
-                        tay
-                        lda  #0
-                        sta  $targetName,y
-                        sta  $targetName+1,y
-                        sta  $targetName+2,y
-                        sta  $targetName+3,y
-                        sta  $targetName+4,y
-                    """) // TODO use a subroutine for this
-                    }
-                }
-                else -> TODO("assign float 0.0 to $target")
-            }
-        } else {
-            // non-zero value
-            val constFloat = asmgen.getFloatConst(float)
-            when {
-                targetIdent != null -> {
-                    val targetName = asmgen.asmIdentifierName(targetIdent)
-                    asmgen.out("""
-                            lda  $constFloat
-                            sta  $targetName
-                            lda  $constFloat+1
-                            sta  $targetName+1
-                            lda  $constFloat+2
-                            sta  $targetName+2
-                            lda  $constFloat+3
-                            sta  $targetName+3
-                            lda  $constFloat+4
-                            sta  $targetName+4
-                        """)
-                }
-                targetArrayIdx!=null -> {
-                    val index = targetArrayIdx.arrayspec.index
-                    val arrayVarName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
-                    if(index is NumericLiteralValue) {
-                        val indexValue = index.number.toInt() * C64MachineDefinition.FLOAT_MEM_SIZE
-                        asmgen.out("""
-                            lda  $constFloat
-                            sta  $arrayVarName+$indexValue
-                            lda  $constFloat+1
-                            sta  $arrayVarName+$indexValue+1
-                            lda  $constFloat+2
-                            sta  $arrayVarName+$indexValue+2
-                            lda  $constFloat+3
-                            sta  $arrayVarName+$indexValue+3
-                            lda  $constFloat+4
-                            sta  $arrayVarName+$indexValue+4
-                        """)
-                    } else {
-                        asmgen.translateArrayIndexIntoA(targetArrayIdx)
-                        asmgen.out("""
-                            sta  ${C64Zeropage.SCRATCH_REG}
-                            asl  a
-                            asl  a
-                            clc
-                            adc  ${C64Zeropage.SCRATCH_REG}
-                            tay
-                            lda  $constFloat
-                            sta  $arrayVarName,y
-                            lda  $constFloat+1
-                            sta  $arrayVarName+1,y
-                            lda  $constFloat+2
-                            sta  $arrayVarName+2,y
-                            lda  $constFloat+3
-                            sta  $arrayVarName+3,y
-                            lda  $constFloat+4
-                            sta  $arrayVarName+4,y
-                        """)        // TODO use a subroutine for this
-                    }
-                }
-                else -> TODO("assign float $float to $target")
-            }
-        }
-    }
-
-    internal fun assignFromMemoryByte(target: AssignTarget, address: Int?, identifier: IdentifierReference?) {
-        val targetIdent = target.identifier
-        val targetArrayIdx = target.arrayindexed
-        if(address!=null) {
-            when {
-                target.register!=null -> {
-                    asmgen.out("  ld${target.register.name.toLowerCase()}  ${address.toHex()}")
-                }
-                targetIdent!=null -> {
-                    val targetName = asmgen.asmIdentifierName(targetIdent)
-                    asmgen.out("""
-                        lda  ${address.toHex()}
-                        sta  $targetName
-                        """)
-                }
-                target.memoryAddress!=null -> {
-                    asmgen.out("  ldy  ${address.toHex()}")
-                    storeRegisterInMemoryAddress(Register.Y, target.memoryAddress)
-                }
-                targetArrayIdx!=null -> {
-                    val index = targetArrayIdx.arrayspec.index
-                    val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
-                    TODO("assign memory byte at $address to array $targetName [ $index ]")
-                }
-                else -> TODO("assign memory byte $target")
-            }
-        }
-        else if(identifier!=null) {
-            val sourceName = asmgen.asmIdentifierName(identifier)
-            when {
-                target.register!=null -> {
-                    asmgen.out("""
-                        ldy  #0
-                        lda  ($sourceName),y
-                    """)
-                    when(target.register){
-                        Register.A -> {}
-                        Register.X -> asmgen.out("  tax")
-                        Register.Y -> asmgen.out("  tay")
-                    }
-                }
-                targetIdent!=null -> {
-                    val targetName = asmgen.asmIdentifierName(targetIdent)
-                    asmgen.out("""
-                        ldy  #0
-                        lda  ($sourceName),y
-                        sta  $targetName
-                    """)
-                }
-                target.memoryAddress!=null -> {
-                    asmgen.out("  ldy  $sourceName")
-                    storeRegisterInMemoryAddress(Register.Y, target.memoryAddress)
-                }
-                targetArrayIdx!=null -> {
-                    val index = targetArrayIdx.arrayspec.index
-                    val targetName = asmgen.asmIdentifierName(targetArrayIdx.identifier)
-                    TODO("assign memory byte $sourceName to array $targetName [ $index ]")
-                }
-                else -> TODO("assign memory byte $target")
-            }
-        }
-    }
-
-    private fun popAndWriteArrayvalueWithIndexA(arrayDt: DataType, variablename: String) {
-        when (arrayDt) {
-            DataType.STR, DataType.ARRAY_UB, DataType.ARRAY_B ->
-                asmgen.out("  tay |  inx |  lda  $ESTACK_LO_HEX,x  | sta  $variablename,y")
-            DataType.ARRAY_UW, DataType.ARRAY_W ->
-                asmgen.out("  asl  a |  tay |  inx |  lda  $ESTACK_LO_HEX,x |  sta  $variablename,y |  lda  $ESTACK_HI_HEX,x |  sta $variablename+1,y")
-            DataType.ARRAY_F ->
-                // index * 5 is done in the subroutine that's called
-                asmgen.out("""
-                    sta  $ESTACK_LO_HEX,x
-                    dex
-                    lda  #<$variablename
-                    ldy  #>$variablename
-                    jsr  c64flt.pop_float_to_indexed_var
-                """)
-            else ->
-                throw AssemblyError("weird array type")
-        }
-    }
-}

compiler/src/prog8/compiler/target/c64/codegen/FunctionCallAsmGen.kt

@@ -1,230 +1,262 @@
 package prog8.compiler.target.c64.codegen
 
 import prog8.ast.IFunctionCall
+import prog8.ast.Node
 import prog8.ast.Program
 import prog8.ast.base.*
 import prog8.ast.expressions.*
-import prog8.ast.statements.AssignTarget
+import prog8.ast.statements.RegisterOrStatusflag
 import prog8.ast.statements.Subroutine
 import prog8.ast.statements.SubroutineParameter
-import prog8.compiler.toHex
 import prog8.compiler.AssemblyError
-import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_HI_HEX
-import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_HEX
+import prog8.compiler.target.c64.codegen.assignment.*
 
 
 internal class FunctionCallAsmGen(private val program: Program, private val asmgen: AsmGen) {
 
-    internal fun translateFunctionCall(stmt: IFunctionCall) {
+    internal fun translateFunctionCallStatement(stmt: IFunctionCall) {
+        val sub = stmt.target.targetSubroutine(program.namespace)!!
+        val preserveStatusRegisterAfterCall = sub.asmReturnvaluesRegisters.any {it.statusflag!=null}
+        translateFunctionCall(stmt, preserveStatusRegisterAfterCall)
+        // functioncalls no longer return results on the stack, so simply ignore the results in the registers
+        if(preserveStatusRegisterAfterCall)
+            asmgen.out("  plp\t; restore status flags from call")
+    }
+
+
+    internal fun translateFunctionCall(stmt: IFunctionCall, preserveStatusRegisterAfterCall: Boolean) {
         // output the code to setup the parameters and perform the actual call
         // does NOT output the code to deal with the result values!
         val sub = stmt.target.targetSubroutine(program.namespace) ?: throw AssemblyError("undefined subroutine ${stmt.target}")
-        if(Register.X in sub.asmClobbers)
-            asmgen.out("  stx  c64.SCRATCH_ZPREGX")        // we only save X for now (required! is the eval stack pointer), screw A and Y...
+        val saveX = CpuRegister.X in sub.asmClobbers || sub.regXasResult() || sub.regXasParam()
+        if(saveX)
+            asmgen.saveRegister(CpuRegister.X, preserveStatusRegisterAfterCall, (stmt as Node).definingSubroutine()!!)
 
-        val subName = asmgen.asmIdentifierName(stmt.target)
+        val subName = asmgen.asmSymbolName(stmt.target)
         if(stmt.args.isNotEmpty()) {
-            for(arg in sub.parameters.withIndex().zip(stmt.args)) {
-                translateFuncArguments(arg.first, arg.second, sub)
+            if(sub.asmParameterRegisters.isEmpty()) {
+                // via variables
+                for(arg in sub.parameters.withIndex().zip(stmt.args)) {
+                    argumentViaVariable(sub, arg.first, arg.second)
+                }
+            } else {
+                // via registers
+                if(sub.parameters.size==1) {
+                    // just a single parameter, no risk of clobbering registers
+                    argumentViaRegister(sub, IndexedValue(0, sub.parameters.single()), stmt.args[0])
+                } else {
+                    // multiple register arguments, risk of register clobbering.
+                    // evaluate arguments onto the stack, and load the registers from the evaluated values on the stack.
+                    when {
+                        stmt.args.all {it is AddressOf ||
+                                it is NumericLiteralValue ||
+                                it is StringLiteralValue ||
+                                it is ArrayLiteralValue ||
+                                it is IdentifierReference} -> {
+                            // no risk of clobbering for these simple argument types. Optimize the register loading.
+                            for(arg in sub.parameters.withIndex().zip(stmt.args)) {
+                                argumentViaRegister(sub, arg.first, arg.second)
+                            }
+                        }
+                        else -> {
+                            // Risk of clobbering due to complex expression args. Work via the stack.
+                            registerArgsViaStackEvaluation(stmt, sub)
+                        }
+                    }
+                }
             }
         }
         asmgen.out("  jsr  $subName")
 
-        if(Register.X in sub.asmClobbers)
-            asmgen.out("  ldx  c64.SCRATCH_ZPREGX")        // restore X again
+        if(preserveStatusRegisterAfterCall) {
+            asmgen.out("  php\t; save status flags from call")
+            // note: the containing statement (such as the FunctionCallStatement or the Assignment or the Expression)
+            //       must take care of popping this value again at the end!
+        }
+
+        if(saveX)
+            asmgen.restoreRegister(CpuRegister.X, preserveStatusRegisterAfterCall)
     }
 
-    private fun translateFuncArguments(parameter: IndexedValue<SubroutineParameter>, value: Expression, sub: Subroutine) {
-        val sourceIDt = value.inferType(program)
-        if(!sourceIDt.isKnown)
-            throw AssemblyError("arg type unknown")
-        val sourceDt = sourceIDt.typeOrElse(DataType.STRUCT)
-        if(!argumentTypeCompatible(sourceDt, parameter.value.type))
+    private fun registerArgsViaStackEvaluation(stmt: IFunctionCall, sub: Subroutine) {
+        // this is called when one or more of the arguments are 'complex' and
+        // cannot be assigned to a register easily or risk clobbering other registers.
+
+        if(sub.parameters.isEmpty())
+            return
+
+        // 1. load all arguments reversed onto the stack: first arg goes last (is on top).
+        for (arg in stmt.args.reversed())
+            asmgen.translateExpression(arg)
+
+        var argForCarry: IndexedValue<Pair<Expression, RegisterOrStatusflag>>? = null
+        var argForXregister: IndexedValue<Pair<Expression, RegisterOrStatusflag>>? = null
+        var argForAregister: IndexedValue<Pair<Expression, RegisterOrStatusflag>>? = null
+
+        asmgen.out("  inx")     // align estack pointer
+
+        for(argi in stmt.args.zip(sub.asmParameterRegisters).withIndex()) {
+            when {
+                argi.value.second.statusflag == Statusflag.Pc -> {
+                    require(argForCarry == null)
+                    argForCarry = argi
+                }
+                argi.value.second.statusflag != null -> throw AssemblyError("can only use Carry as status flag parameter")
+                argi.value.second.registerOrPair in setOf(RegisterOrPair.X, RegisterOrPair.AX, RegisterOrPair.XY) -> {
+                    require(argForXregister==null)
+                    argForXregister = argi
+                }
+                argi.value.second.registerOrPair in setOf(RegisterOrPair.A, RegisterOrPair.AY) -> {
+                    require(argForAregister == null)
+                    argForAregister = argi
+                }
+                argi.value.second.registerOrPair == RegisterOrPair.Y -> {
+                    asmgen.out("  ldy  P8ESTACK_LO+${argi.index},x")
+                }
+                else -> throw AssemblyError("weird argument")
+            }
+        }
+
+        if(argForCarry!=null) {
+            asmgen.out("""
+                lda  P8ESTACK_LO+${argForCarry.index},x
+                beq  +
+                sec
+                bcs  ++
++               clc
++               php""")             // push the status flags
+        }
+
+        if(argForAregister!=null) {
+            when(argForAregister.value.second.registerOrPair) {
+                RegisterOrPair.A -> asmgen.out("  lda  P8ESTACK_LO+${argForAregister.index},x")
+                RegisterOrPair.AY -> asmgen.out("  lda  P8ESTACK_LO+${argForAregister.index},x |  ldy  P8ESTACK_HI+${argForAregister.index},x")
+                else -> throw AssemblyError("weird arg")
+            }
+        }
+
+        if(argForXregister!=null) {
+
+            if(argForAregister!=null)
+                asmgen.out("  pha")
+            when(argForXregister.value.second.registerOrPair) {
+                RegisterOrPair.X -> asmgen.out("  lda  P8ESTACK_LO+${argForXregister.index},x |  tax")
+                RegisterOrPair.AX -> asmgen.out("  ldy  P8ESTACK_LO+${argForXregister.index},x |  lda  P8ESTACK_HI+${argForXregister.index},x |  tax |  tya")
+                RegisterOrPair.XY -> asmgen.out("  ldy  P8ESTACK_HI+${argForXregister.index},x |  lda  P8ESTACK_LO+${argForXregister.index},x |  tax")
+                else -> throw AssemblyError("weird arg")
+            }
+            if(argForAregister!=null)
+                asmgen.out("  pla")
+        } else {
+            repeat(sub.parameters.size - 1) { asmgen.out("  inx") }       // unwind stack
+        }
+
+        if(argForCarry!=null)
+            asmgen.out("  plp")       // set the carry flag back to correct value
+    }
+
+    private fun argumentViaVariable(sub: Subroutine, parameter: IndexedValue<SubroutineParameter>, value: Expression) {
+        // pass parameter via a regular variable (not via registers)
+        val valueIDt = value.inferType(program)
+        if(!valueIDt.isKnown)
+            throw AssemblyError("unknown dt")
+        val valueDt = valueIDt.typeOrElse(DataType.STRUCT)
+        if(!isArgumentTypeCompatible(valueDt, parameter.value.type))
             throw AssemblyError("argument type incompatible")
-        if(sub.asmParameterRegisters.isEmpty()) {
-            // pass parameter via a variable
-            val paramVar = parameter.value
-            val scopedParamVar = (sub.scopedname+"."+paramVar.name).split(".")
-            val target = AssignTarget(null, IdentifierReference(scopedParamVar, sub.position), null, null, sub.position)
-            target.linkParents(value.parent)
-            when (value) {
-                is NumericLiteralValue -> {
-                    // optimize when the argument is a constant literal
-                    when(parameter.value.type) {
-                        in ByteDatatypes -> asmgen.assignFromByteConstant(target, value.number.toShort())
-                        in WordDatatypes -> asmgen.assignFromWordConstant(target, value.number.toInt())
-                        DataType.FLOAT -> asmgen.assignFromFloatConstant(target, value.number.toDouble())
-                        in PassByReferenceDatatypes -> throw AssemblyError("can't pass string/array as arguments?")
-                        else -> throw AssemblyError("weird parameter datatype")
-                    }
-                }
-                is IdentifierReference -> {
-                    // optimize when the argument is a variable
-                    when (parameter.value.type) {
-                        in ByteDatatypes -> asmgen.assignFromByteVariable(target, value)
-                        in WordDatatypes -> asmgen.assignFromWordVariable(target, value)
-                        DataType.FLOAT -> asmgen.assignFromFloatVariable(target, value)
-                        in PassByReferenceDatatypes -> throw AssemblyError("can't pass string/array as arguments?")
-                        else -> throw AssemblyError("weird parameter datatype")
-                    }
-                }
-                is RegisterExpr -> {
-                    asmgen.assignFromRegister(target, value.register)
-                }
-                is DirectMemoryRead -> {
-                    when(value.addressExpression) {
+
+        val varName = asmgen.asmVariableName(sub.scopedname+"."+parameter.value.name)
+        asmgen.assignExpressionToVariable(value, varName, parameter.value.type, sub)
+    }
+
+    private fun argumentViaRegister(sub: Subroutine, parameter: IndexedValue<SubroutineParameter>, value: Expression) {
+        // pass argument via a register parameter
+        val valueIDt = value.inferType(program)
+        if(!valueIDt.isKnown)
+            throw AssemblyError("unknown dt")
+        val valueDt = valueIDt.typeOrElse(DataType.STRUCT)
+        if(!isArgumentTypeCompatible(valueDt, parameter.value.type))
+            throw AssemblyError("argument type incompatible")
+
+        val paramRegister = sub.asmParameterRegisters[parameter.index]
+        val statusflag = paramRegister.statusflag
+        val register = paramRegister.registerOrPair
+        val requiredDt = parameter.value.type
+        if(requiredDt!=valueDt) {
+            if(valueDt largerThan requiredDt)
+                throw AssemblyError("can only convert byte values to word param types")
+        }
+        when {
+            statusflag!=null -> {
+                if(requiredDt!=valueDt)
+                    throw AssemblyError("for statusflag, byte value is required")
+                if (statusflag == Statusflag.Pc) {
+                    // this param needs to be set last, right before the jsr
+                    // for now, this is already enforced on the subroutine definition by the Ast Checker
+                    when(value) {
                         is NumericLiteralValue -> {
-                            val address = (value.addressExpression as NumericLiteralValue).number.toInt()
-                            asmgen.assignFromMemoryByte(target, address, null)
+                            val carrySet = value.number.toInt() != 0
+                            asmgen.out(if(carrySet) "  sec" else "  clc")
                         }
                         is IdentifierReference -> {
-                            asmgen.assignFromMemoryByte(target, null, value.addressExpression as IdentifierReference)
-                        }
-                        else -> {
-                            asmgen.translateExpression(value.addressExpression)
-                            asmgen.out("  jsr  prog8_lib.read_byte_from_address |  inx")
-                            asmgen.assignFromRegister(target, Register.A)
-                        }
-                    }
-                }
-                else -> {
-                    asmgen.translateExpression(value)
-                    asmgen.assignFromEvalResult(target)
-                }
-            }
-        } else {
-            // pass parameter via a register parameter
-            val paramRegister = sub.asmParameterRegisters[parameter.index]
-            val statusflag = paramRegister.statusflag
-            val register = paramRegister.registerOrPair
-            val stack = paramRegister.stack
-            when {
-                stack -> {
-                    // push arg onto the stack
-                    // note: argument order is reversed (first argument will be deepest on the stack)
-                    asmgen.translateExpression(value)
-                }
-                statusflag!=null -> {
-                    if (statusflag == Statusflag.Pc) {
-                        // this param needs to be set last, right before the jsr
-                        // for now, this is already enforced on the subroutine definition by the Ast Checker
-                        when(value) {
-                            is NumericLiteralValue -> {
-                                val carrySet = value.number.toInt() != 0
-                                asmgen.out(if(carrySet) "  sec" else "  clc")
-                            }
-                            is IdentifierReference -> {
-                                val sourceName = asmgen.asmIdentifierName(value)
-                                asmgen.out("""
+                            val sourceName = asmgen.asmVariableName(value)
+                            asmgen.out("""
+            pha
             lda  $sourceName
             beq  +
             sec  
             bcs  ++
 +           clc
-+
++           pla
 """)
-                            }
-                            is RegisterExpr -> {
-                                when(value.register) {
-                                    Register.A -> asmgen.out("  cmp  #0")
-                                    Register.X -> asmgen.out("  txa")
-                                    Register.Y -> asmgen.out("  tya")
-                                }
-                                asmgen.out("""
-            beq  +
-            sec
-            bcs  ++
-+           clc
-+
-""")
-                            }
-                            else -> {
-                                asmgen.translateExpression(value)
-                                asmgen.out("""
-            inx                        
-            lda  $ESTACK_LO_HEX,x
-            beq  +
-            sec  
-            bcs  ++
-+           clc
-+
-""")
-                            }
-                        }
-                    }
-                    else throw AssemblyError("can only use Carry as status flag parameter")
-                }
-                register!=null && register.name.length==1 -> {
-                    when (value) {
-                        is NumericLiteralValue -> {
-                            val target = AssignTarget(Register.valueOf(register.name), null, null, null, sub.position)
-                            target.linkParents(value.parent)
-                            asmgen.assignFromByteConstant(target, value.number.toShort())
-                        }
-                        is IdentifierReference -> {
-                            val target = AssignTarget(Register.valueOf(register.name), null, null, null, sub.position)
-                            target.linkParents(value.parent)
-                            asmgen.assignFromByteVariable(target, value)
                         }
                         else -> {
-                            asmgen.translateExpression(value)
-                            when(register) {
-                                RegisterOrPair.A -> asmgen.out("  inx | lda  $ESTACK_LO_HEX,x")
-                                RegisterOrPair.X -> throw AssemblyError("can't pop into X register - use a variable instead")
-                                RegisterOrPair.Y -> asmgen.out("  inx | ldy  $ESTACK_LO_HEX,x")
-                                else -> throw AssemblyError("cannot assign to register pair")
-                            }
+                            asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
+                            asmgen.out("""
+                                beq  +
+                                sec
+                                bcs  ++
++                               clc
++""")
                         }
                     }
                 }
-                register!=null && register.name.length==2 -> {
-                    // register pair as a 16-bit value (only possible for subroutine parameters)
-                    when (value) {
-                        is NumericLiteralValue -> {
-                            // optimize when the argument is a constant literal
-                            val hex = value.number.toHex()
-                            when (register) {
-                                RegisterOrPair.AX -> asmgen.out("  lda  #<$hex  |  ldx  #>$hex")
-                                RegisterOrPair.AY -> asmgen.out("  lda  #<$hex  |  ldy  #>$hex")
-                                RegisterOrPair.XY -> asmgen.out("  ldx  #<$hex  |  ldy  #>$hex")
-                                else -> {}
-                            }
-                        }
-                        is AddressOf -> {
-                            // optimize when the argument is an address of something
-                            val sourceName = asmgen.asmIdentifierName(value.identifier)
-                            when (register) {
-                                RegisterOrPair.AX -> asmgen.out("  lda  #<$sourceName  |  ldx  #>$sourceName")
-                                RegisterOrPair.AY -> asmgen.out("  lda  #<$sourceName  |  ldy  #>$sourceName")
-                                RegisterOrPair.XY -> asmgen.out("  ldx  #<$sourceName  |  ldy  #>$sourceName")
-                                else -> {}
-                            }
-                        }
-                        is IdentifierReference -> {
-                            val sourceName = asmgen.asmIdentifierName(value)
-                            when (register) {
-                                RegisterOrPair.AX -> asmgen.out("  lda  $sourceName  |  ldx  $sourceName+1")
-                                RegisterOrPair.AY -> asmgen.out("  lda  $sourceName  |  ldy  $sourceName+1")
-                                RegisterOrPair.XY -> asmgen.out("  ldx  $sourceName  |  ldy  $sourceName+1")
-                                else -> {}
-                            }
-                        }
-                        else -> {
-                            asmgen.translateExpression(value)
-                            if (register == RegisterOrPair.AX || register == RegisterOrPair.XY)
-                                throw AssemblyError("can't use X register here - use a variable")
-                            else if (register == RegisterOrPair.AY)
-                                asmgen.out("  inx |  lda  $ESTACK_LO_HEX,x  |  ldy  $ESTACK_HI_HEX,x")
+                else throw AssemblyError("can only use Carry as status flag parameter")
+            }
+            else -> {
+                // via register or register pair
+                register!!
+                if(requiredDt largerThan valueDt) {
+                    // we need to sign extend the source, do this via temporary word variable
+                    val scratchVar = asmgen.asmVariableName("P8ZP_SCRATCH_W1")
+                    asmgen.assignExpressionToVariable(value, scratchVar, DataType.UBYTE, sub)
+                    asmgen.signExtendVariableLsb(scratchVar, valueDt)
+                    asmgen.assignVariableToRegister(scratchVar, register)
+                }
+                else {
+                    val target = AsmAssignTarget.fromRegisters(register, sub, program, asmgen)
+                    val src = if(valueDt in PassByReferenceDatatypes) {
+                        if(value is IdentifierReference) {
+                            val addr = AddressOf(value, Position.DUMMY)
+                            AsmAssignSource.fromAstSource(addr, program, asmgen).adjustSignedUnsigned(target)
+                        } else {
+                            AsmAssignSource.fromAstSource(value, program, asmgen).adjustSignedUnsigned(target)
                         }
+                    } else {
+                        AsmAssignSource.fromAstSource(value, program, asmgen).adjustSignedUnsigned(target)
                     }
+                    asmgen.translateNormalAssignment(AsmAssignment(src, target, false, Position.DUMMY))
                 }
             }
         }
     }
 
-    private fun argumentTypeCompatible(argType: DataType, paramType: DataType): Boolean {
+    private fun isArgumentTypeCompatible(argType: DataType, paramType: DataType): Boolean {
         if(argType isAssignableTo paramType)
             return true
+        if(argType in ByteDatatypes && paramType in ByteDatatypes)
+            return true
+        if(argType in WordDatatypes && paramType in WordDatatypes)
+            return true
 
         // we have a special rule for some types.
         // strings are assignable to UWORD, for example, and vice versa

compiler/src/prog8/compiler/target/c64/codegen/PostIncrDecrAsmGen.kt

@@ -4,11 +4,9 @@ import prog8.ast.Program
 import prog8.ast.base.*
 import prog8.ast.expressions.IdentifierReference
 import prog8.ast.expressions.NumericLiteralValue
-import prog8.ast.expressions.RegisterExpr
 import prog8.ast.statements.PostIncrDecr
-import prog8.compiler.toHex
 import prog8.compiler.AssemblyError
-import prog8.compiler.target.c64.C64MachineDefinition.C64Zeropage
+import prog8.compiler.toHex
 
 
 internal class PostIncrDecrAsmGen(private val program: Program, private val asmgen: AsmGen) {
@@ -17,28 +15,11 @@ internal class PostIncrDecrAsmGen(private val program: Program, private val asmg
         val targetIdent = stmt.target.identifier
         val targetMemory = stmt.target.memoryAddress
         val targetArrayIdx = stmt.target.arrayindexed
-        val targetRegister = stmt.target.register
+        val scope = stmt.definingSubroutine()
         when {
-            targetRegister!=null -> {
-                when(targetRegister) {
-                    Register.A -> {
-                        if(incr)
-                            asmgen.out("  clc |  adc  #1 ")
-                        else
-                            asmgen.out("  sec |  sbc  #1 ")
-                    }
-                    Register.X -> {
-                        if(incr) asmgen.out("  inx") else asmgen.out("  dex")
-                    }
-                    Register.Y -> {
-                        if(incr) asmgen.out("  iny") else asmgen.out("  dey")
-                    }
-                }
-            }
             targetIdent!=null -> {
-                val what = asmgen.asmIdentifierName(targetIdent)
-                val dt = stmt.target.inferType(program, stmt).typeOrElse(DataType.STRUCT)
-                when (dt) {
+                val what = asmgen.asmVariableName(targetIdent)
+                when (stmt.target.inferType(program).typeOrElse(DataType.STRUCT)) {
                     in ByteDatatypes -> asmgen.out(if (incr) "  inc  $what" else "  dec  $what")
                     in WordDatatypes -> {
                         if(incr)
@@ -53,7 +34,7 @@ internal class PostIncrDecrAsmGen(private val program: Program, private val asmg
                     }
                     DataType.FLOAT -> {
                         asmgen.out("  lda  #<$what |  ldy  #>$what")
-                        asmgen.out(if(incr) "  jsr  c64flt.inc_var_f" else "  jsr  c64flt.dec_var_f")
+                        asmgen.out(if(incr) "  jsr  floats.inc_var_f" else "  jsr  floats.dec_var_f")
                     }
                     else -> throw AssemblyError("need numeric type")
                 }
@@ -65,86 +46,82 @@ internal class PostIncrDecrAsmGen(private val program: Program, private val asmg
                         asmgen.out(if(incr) "  inc  $what" else "  dec  $what")
                     }
                     is IdentifierReference -> {
-                        val what = asmgen.asmIdentifierName(addressExpr)
-                        asmgen.out(if(incr) "  inc  $what" else "  dec  $what")
+                        val what = asmgen.asmVariableName(addressExpr)
+                        asmgen.out("  lda  $what |  sta  (+) +1 |  lda  $what+1 |  sta  (+) +2")
+                        if(incr)
+                            asmgen.out("+\tinc  ${'$'}ffff\t; modified")
+                        else
+                            asmgen.out("+\tdec  ${'$'}ffff\t; modified")
+                    }
+                    else -> {
+                        asmgen.assignExpressionToRegister(addressExpr, RegisterOrPair.AY)
+                        asmgen.out("  sta  (+) + 1 |  sty  (+) + 2")
+                        if(incr)
+                            asmgen.out("+\tinc  ${'$'}ffff\t; modified")
+                        else
+                            asmgen.out("+\tdec  ${'$'}ffff\t; modified")
                     }
-                    else -> throw AssemblyError("weird target type $targetMemory")
                 }
             }
             targetArrayIdx!=null -> {
-                val index = targetArrayIdx.arrayspec.index
-                val what = asmgen.asmIdentifierName(targetArrayIdx.identifier)
-                val arrayDt = targetArrayIdx.identifier.inferType(program).typeOrElse(DataType.STRUCT)
-                val elementDt = ArrayElementTypes.getValue(arrayDt)
-                when(index) {
-                    is NumericLiteralValue -> {
-                        val indexValue = index.number.toInt() * elementDt.memorySize()
-                        when(elementDt) {
-                            in ByteDatatypes -> asmgen.out(if (incr) "  inc  $what+$indexValue" else "  dec  $what+$indexValue")
-                            in WordDatatypes -> {
-                                if(incr)
-                                    asmgen.out(" inc  $what+$indexValue |  bne  + |  inc  $what+$indexValue+1 |+")
-                                else
-                                    asmgen.out("""
-        lda  $what+$indexValue
-        bne  +
-        dec  $what+$indexValue+1
-+       dec  $what+$indexValue 
+                val asmArrayvarname = asmgen.asmVariableName(targetArrayIdx.arrayvar)
+                val elementDt = targetArrayIdx.inferType(program).typeOrElse(DataType.STRUCT)
+                if(targetArrayIdx.indexer.indexNum!=null) {
+                    val indexValue = targetArrayIdx.indexer.constIndex()!! * elementDt.memorySize()
+                    when(elementDt) {
+                        in ByteDatatypes -> asmgen.out(if (incr) "  inc  $asmArrayvarname+$indexValue" else "  dec  $asmArrayvarname+$indexValue")
+                        in WordDatatypes -> {
+                            if(incr)
+                                asmgen.out(" inc  $asmArrayvarname+$indexValue |  bne  + |  inc  $asmArrayvarname+$indexValue+1 |+")
+                            else
+                                asmgen.out("""
+    lda  $asmArrayvarname+$indexValue
+    bne  +
+    dec  $asmArrayvarname+$indexValue+1
++       dec  $asmArrayvarname+$indexValue 
 """)
-                            }
-                            DataType.FLOAT -> {
-                                asmgen.out("  lda  #<$what+$indexValue |  ldy  #>$what+$indexValue")
-                                asmgen.out(if(incr) "  jsr  c64flt.inc_var_f" else "  jsr  c64flt.dec_var_f")
-                            }
-                            else -> throw AssemblyError("need numeric type")
                         }
-                    }
-                    is RegisterExpr -> {
-                        // TODO optimize common cases
-                        asmgen.translateArrayIndexIntoA(targetArrayIdx)
-                        incrDecrArrayvalueWithIndexA(incr, arrayDt, what)
-                    }
-                    is IdentifierReference -> {
-                        // TODO optimize common cases
-                        asmgen.translateArrayIndexIntoA(targetArrayIdx)
-                        incrDecrArrayvalueWithIndexA(incr, arrayDt, what)
-                    }
-                    else -> {
-                        // TODO optimize common cases
-                        asmgen.translateArrayIndexIntoA(targetArrayIdx)
-                        incrDecrArrayvalueWithIndexA(incr, arrayDt, what)
+                        DataType.FLOAT -> {
+                            asmgen.out("  lda  #<$asmArrayvarname+$indexValue |  ldy  #>$asmArrayvarname+$indexValue")
+                            asmgen.out(if(incr) "  jsr  floats.inc_var_f" else "  jsr  floats.dec_var_f")
+                        }
+                        else -> throw AssemblyError("need numeric type")
                     }
                 }
-            }
-            else -> throw AssemblyError("weird target type ${stmt.target}")
-        }
-    }
-
-    private fun incrDecrArrayvalueWithIndexA(incr: Boolean, arrayDt: DataType, arrayVarName: String) {
-        asmgen.out("  stx  ${C64Zeropage.SCRATCH_REG_X} |  tax")
-        when(arrayDt) {
-            DataType.STR,
-            DataType.ARRAY_UB, DataType.ARRAY_B -> {
-                asmgen.out(if(incr) "  inc  $arrayVarName,x" else "  dec  $arrayVarName,x")
-            }
-            DataType.ARRAY_UW, DataType.ARRAY_W -> {
-                if(incr)
-                    asmgen.out(" inc  $arrayVarName,x |  bne  + |  inc  $arrayVarName+1,x |+")
                 else
-                    asmgen.out("""
-        lda  $arrayVarName,x
-        bne  +
-        dec  $arrayVarName+1,x
-+       dec  $arrayVarName 
+                {
+                    asmgen.loadScaledArrayIndexIntoRegister(targetArrayIdx, elementDt, CpuRegister.A)
+                    asmgen.saveRegister(CpuRegister.X, false, scope!!)
+                    asmgen.out("  tax")
+                    when(elementDt) {
+                        in ByteDatatypes -> {
+                            asmgen.out(if(incr) "  inc  $asmArrayvarname,x" else "  dec  $asmArrayvarname,x")
+                        }
+                        in WordDatatypes -> {
+                            if(incr)
+                                asmgen.out(" inc  $asmArrayvarname,x |  bne  + |  inc  $asmArrayvarname+1,x |+")
+                            else
+                                asmgen.out("""
+    lda  $asmArrayvarname,x
+    bne  +
+    dec  $asmArrayvarname+1,x
++       dec  $asmArrayvarname 
 """)
+                        }
+                        DataType.FLOAT -> {
+                            asmgen.out("""
+                    ldy  #>$asmArrayvarname
+                    clc
+                    adc  #<$asmArrayvarname
+                    bcc  +
+                    iny
++                       jsr  floats.inc_var_f""")
+                        }
+                        else -> throw AssemblyError("weird array elt dt")
+                    }
+                    asmgen.restoreRegister(CpuRegister.X, false)
+                }
             }
-            DataType.ARRAY_F -> {
-                asmgen.out("  lda  #<$arrayVarName |  ldy  #>$arrayVarName")
-                asmgen.out(if(incr) "  jsr  c64flt.inc_indexed_var_f" else "  jsr  c64flt.dec_indexed_var_f")
-            }
-            else -> throw AssemblyError("weird array dt")
         }
-        asmgen.out("  ldx  ${C64Zeropage.SCRATCH_REG_X}")
     }
-
 }

compiler/src/prog8/compiler/target/c64/codegen/assignment/AsmAssignment.kt

@@ -0,0 +1,194 @@
+package prog8.compiler.target.c64.codegen.assignment
+
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.statements.*
+import prog8.compiler.AssemblyError
+import prog8.compiler.target.c64.codegen.AsmGen
+
+
+internal enum class TargetStorageKind {
+    VARIABLE,
+    ARRAY,
+    MEMORY,
+    REGISTER,
+    STACK
+}
+
+internal enum class SourceStorageKind {
+    LITERALNUMBER,
+    VARIABLE,
+    ARRAY,
+    MEMORY,
+    REGISTER,
+    STACK,              // value is already present on stack
+    EXPRESSION,         // expression in ast-form, still to be evaluated
+}
+
+internal class AsmAssignTarget(val kind: TargetStorageKind,
+                               private val program: Program,
+                               private val asmgen: AsmGen,
+                               val datatype: DataType,
+                               val scope: Subroutine?,
+                               private val variableAsmName: String? = null,
+                               val array: ArrayIndexedExpression? = null,
+                               val memory: DirectMemoryWrite? = null,
+                               val register: RegisterOrPair? = null,
+                               val origAstTarget: AssignTarget? = null
+                               )
+{
+    val constMemoryAddress by lazy { memory?.addressExpression?.constValue(program)?.number?.toInt() ?: 0}
+    val constArrayIndexValue by lazy { array?.indexer?.constIndex() }
+    val asmVarname: String
+        get() = if(array==null)
+            variableAsmName!!
+        else
+            asmgen.asmVariableName(array.arrayvar)
+
+    lateinit var origAssign: AsmAssignment
+
+    init {
+        if(register!=null && datatype !in NumericDatatypes)
+            throw AssemblyError("register must be integer or float type")
+    }
+
+    companion object {
+        fun fromAstAssignment(assign: Assignment, program: Program, asmgen: AsmGen): AsmAssignTarget = with(assign.target) {
+            val idt = inferType(program)
+            if(!idt.isKnown)
+                throw AssemblyError("unknown dt")
+            val dt = idt.typeOrElse(DataType.STRUCT)
+            when {
+                identifier != null -> AsmAssignTarget(TargetStorageKind.VARIABLE, program, asmgen, dt, assign.definingSubroutine(), variableAsmName = asmgen.asmVariableName(identifier!!), origAstTarget =  this)
+                arrayindexed != null -> AsmAssignTarget(TargetStorageKind.ARRAY, program, asmgen, dt, assign.definingSubroutine(), array = arrayindexed, origAstTarget =  this)
+                memoryAddress != null -> AsmAssignTarget(TargetStorageKind.MEMORY, program, asmgen, dt, assign.definingSubroutine(), memory =  memoryAddress, origAstTarget =  this)
+                else -> throw AssemblyError("weird target")
+            }
+        }
+
+        fun fromRegisters(registers: RegisterOrPair, scope: Subroutine?, program: Program, asmgen: AsmGen): AsmAssignTarget =
+                when(registers) {
+                    RegisterOrPair.A,
+                    RegisterOrPair.X,
+                    RegisterOrPair.Y -> AsmAssignTarget(TargetStorageKind.REGISTER, program, asmgen, DataType.UBYTE, scope, register = registers)
+                    RegisterOrPair.AX,
+                    RegisterOrPair.AY,
+                    RegisterOrPair.XY -> AsmAssignTarget(TargetStorageKind.REGISTER, program, asmgen, DataType.UWORD, scope, register = registers)
+                    RegisterOrPair.FAC1,
+                    RegisterOrPair.FAC2 -> AsmAssignTarget(TargetStorageKind.REGISTER, program, asmgen, DataType.FLOAT, scope, register = registers)
+                }
+    }
+}
+
+internal class AsmAssignSource(val kind: SourceStorageKind,
+                               private val program: Program,
+                               private val asmgen: AsmGen,
+                               val datatype: DataType,
+                               private val variableAsmName: String? = null,
+                               val array: ArrayIndexedExpression? = null,
+                               val memory: DirectMemoryRead? = null,
+                               val register: CpuRegister? = null,
+                               val number: NumericLiteralValue? = null,
+                               val expression: Expression? = null
+)
+{
+    val constMemoryAddress by lazy { memory?.addressExpression?.constValue(program)?.number?.toInt() ?: 0}
+    val constArrayIndexValue by lazy { array?.indexer?.constIndex() }
+
+    val asmVarname: String
+        get() = if(array==null)
+            variableAsmName!!
+        else
+            asmgen.asmVariableName(array.arrayvar)
+
+    companion object {
+        fun fromAstSource(indexer: ArrayIndex, program: Program, asmgen: AsmGen): AsmAssignSource {
+            return when {
+                indexer.indexNum!=null -> fromAstSource(indexer.indexNum!!, program, asmgen)
+                indexer.indexVar!=null -> fromAstSource(indexer.indexVar!!, program, asmgen)
+                else -> throw AssemblyError("weird indexer")
+            }
+        }
+
+        fun fromAstSource(value: Expression, program: Program, asmgen: AsmGen): AsmAssignSource {
+            val cv = value.constValue(program)
+            if(cv!=null)
+                return AsmAssignSource(SourceStorageKind.LITERALNUMBER, program, asmgen, cv.type, number = cv)
+
+            return when(value) {
+                is NumericLiteralValue -> AsmAssignSource(SourceStorageKind.LITERALNUMBER, program, asmgen, value.type, number = cv)
+                is StringLiteralValue -> throw AssemblyError("string literal value should not occur anymore for asm generation")
+                is ArrayLiteralValue -> throw AssemblyError("array literal value should not occur anymore for asm generation")
+                is IdentifierReference -> {
+                    val dt = value.inferType(program).typeOrElse(DataType.STRUCT)
+                    AsmAssignSource(SourceStorageKind.VARIABLE, program, asmgen, dt, variableAsmName = asmgen.asmVariableName(value))
+                }
+                is DirectMemoryRead -> {
+                    AsmAssignSource(SourceStorageKind.MEMORY, program, asmgen, DataType.UBYTE, memory = value)
+                }
+                is ArrayIndexedExpression -> {
+                    val dt = value.inferType(program).typeOrElse(DataType.STRUCT)
+                    AsmAssignSource(SourceStorageKind.ARRAY, program, asmgen, dt, array = value)
+                }
+                is FunctionCall -> {
+                    when (val sub = value.target.targetStatement(program.namespace)) {
+                        is Subroutine -> {
+                            val returnType = sub.returntypes.zip(sub.asmReturnvaluesRegisters).firstOrNull { rr -> rr.second.registerOrPair != null }?.first
+                                    ?: throw AssemblyError("can't translate zero return values in assignment")
+
+                            AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, returnType, expression = value)
+                        }
+                        is BuiltinFunctionStatementPlaceholder -> {
+                            val returnType = value.inferType(program)
+                            if(!returnType.isKnown)
+                                throw AssemblyError("unknown dt")
+                            AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, returnType.typeOrElse(DataType.STRUCT), expression = value)
+                        }
+                        else -> {
+                            throw AssemblyError("weird call")
+                        }
+                    }
+                }
+                else -> {
+                    val dt = value.inferType(program)
+                    if(!dt.isKnown)
+                        throw AssemblyError("unknown dt")
+                    AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, dt.typeOrElse(DataType.STRUCT), expression = value)
+                }
+            }
+        }
+    }
+
+    fun adjustSignedUnsigned(target: AsmAssignTarget): AsmAssignSource {
+        // allow some signed/unsigned relaxations
+
+        fun withAdjustedDt(newType: DataType) =
+                AsmAssignSource(kind, program, asmgen, newType, variableAsmName, array, memory, register, number, expression)
+
+        if(target.datatype!=datatype) {
+            if(target.datatype in ByteDatatypes && datatype in ByteDatatypes) {
+                return withAdjustedDt(target.datatype)
+            } else if(target.datatype in WordDatatypes && datatype in WordDatatypes) {
+                return withAdjustedDt(target.datatype)
+            }
+        }
+        return this
+    }
+
+}
+
+
+internal class AsmAssignment(val source: AsmAssignSource,
+                             val target: AsmAssignTarget,
+                             val isAugmentable: Boolean,
+                             val position: Position) {
+
+    init {
+        if(target.register !in setOf(RegisterOrPair.XY, RegisterOrPair.AX, RegisterOrPair.AY))
+            require(source.datatype != DataType.STRUCT) { "must not be placeholder datatype" }
+            require(source.datatype.memorySize() <= target.datatype.memorySize()) {
+                "source storage size must be less or equal to target datatype storage size"
+            }
+    }
+}

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

@@ -0,0 +1,118 @@
+package prog8.compiler.target.cx16
+
+import prog8.ast.Program
+import prog8.compiler.*
+import prog8.compiler.target.CpuType
+import prog8.compiler.target.IMachineDefinition
+import prog8.compiler.target.c64.C64MachineDefinition
+import prog8.parser.ModuleImporter
+import java.io.IOException
+
+internal object CX16MachineDefinition: IMachineDefinition {
+
+    override val cpu = CpuType.CPU65c02
+
+    // 5-byte cbm MFLPT format limitations:
+    override val FLOAT_MAX_POSITIVE = 1.7014118345e+38         // bytes: 255,127,255,255,255
+    override val FLOAT_MAX_NEGATIVE = -1.7014118345e+38        // bytes: 255,255,255,255,255
+    override val FLOAT_MEM_SIZE = 5
+    override val POINTER_MEM_SIZE = 2
+    override val BASIC_LOAD_ADDRESS = 0x0801
+    override val RAW_LOAD_ADDRESS = 0x8000
+
+    // the 2*256 byte evaluation stack (on which bytes, words, and even floats are stored during calculations)
+    // and some heavily used string constants derived from the two values above
+    override val ESTACK_LO = 0x0400        //  $0400-$04ff inclusive
+    override val ESTACK_HI = 0x0500        //  $0500-$05ff inclusive
+
+    override lateinit var zeropage: Zeropage
+
+    override fun getFloat(num: Number) = C64MachineDefinition.Mflpt5.fromNumber(num)
+
+    override fun getFloatRomConst(number: Double): String? = null       // Cx16 has no pulblic ROM float locations
+    override fun importLibs(compilerOptions: CompilationOptions, importer: ModuleImporter, program: Program) {
+        if (compilerOptions.launcher == LauncherType.BASIC || compilerOptions.output == OutputType.PRG)
+            importer.importLibraryModule(program, "syslib")
+    }
+
+    override fun launchEmulator(programName: String) {
+        for(emulator in listOf("x16emu")) {
+            println("\nStarting Commander X16 emulator $emulator...")
+            val cmdline = listOf(emulator, "-rom", "/usr/share/x16-rom/rom.bin", "-scale", "2",
+                    "-run", "-prg", programName + ".prg")
+            val processb = ProcessBuilder(cmdline).inheritIO()
+            val process: Process
+            try {
+                process=processb.start()
+            } catch(x: IOException) {
+                continue  // try the next emulator executable
+            }
+            process.waitFor()
+            break
+        }
+    }
+
+    override fun isRegularRAMaddress(address: Int): Boolean = address < 0x9f00 || address in 0xa000..0xbfff
+
+    override fun initializeZeropage(compilerOptions: CompilationOptions) {
+        zeropage = CX16Zeropage(compilerOptions)
+    }
+
+    // 6502 opcodes (including aliases and illegal opcodes), these cannot be used as variable or label names
+    override val opcodeNames = setOf("adc", "and", "asl", "bcc", "bcs",
+            "beq", "bge", "bit", "blt", "bmi", "bne", "bpl", "brk", "bvc", "bvs", "clc",
+            "cld", "cli", "clv", "cmp", "cpx", "cpy", "dec", "dex", "dey",
+            "eor", "gcc", "gcs", "geq", "gge", "glt", "gmi", "gne", "gpl", "gvc", "gvs",
+            "inc", "inx", "iny", "jmp", "jsr",
+            "lda", "ldx", "ldy", "lsr", "nop", "ora", "pha", "php",
+            "pla", "plp", "rol", "ror", "rti", "rts", "sbc",
+            "sec", "sed", "sei",
+            "sta", "stx", "sty", "tax", "tay", "tsx", "txa", "txs", "tya",
+            "bra", "phx", "phy", "plx", "ply", "stz", "trb", "tsb", "bbr", "bbs",
+            "rmb", "smb", "stp", "wai")
+
+
+    internal class CX16Zeropage(options: CompilationOptions) : Zeropage(options) {
+
+        override val SCRATCH_B1 = 0x79      // temp storage for a single byte
+        override val SCRATCH_REG = 0x7a     // temp storage for a register, must be B1+1
+        override val SCRATCH_W1 = 0x7c      // temp storage 1 for a word  $7c+$7d
+        override val SCRATCH_W2 = 0x7e      // temp storage 2 for a word  $7e+$7f
+
+
+        init {
+            if (options.floats && options.zeropage !in setOf(ZeropageType.BASICSAFE, ZeropageType.DONTUSE ))
+                throw CompilerException("when floats are enabled, zero page type should be 'basicsafe' or 'dontuse'")
+
+            // the addresses 0x02 to 0x21 (inclusive) are taken for sixteen virtual 16-bit api registers.
+
+            when (options.zeropage) {
+                ZeropageType.FULL -> {
+                    free.addAll(0x22..0xff)
+                    free.removeAll(listOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_W1, SCRATCH_W1 + 1, SCRATCH_W2, SCRATCH_W2 + 1))
+                }
+                ZeropageType.KERNALSAFE -> {
+                    free.addAll(0x22..0x7f)
+                    free.addAll(0xa9..0xff)
+                    free.removeAll(listOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_W1, SCRATCH_W1 + 1, SCRATCH_W2, SCRATCH_W2 + 1))
+                }
+                ZeropageType.BASICSAFE -> {
+                    free.addAll(0x22..0x7f)
+                    free.removeAll(listOf(SCRATCH_B1, SCRATCH_REG, SCRATCH_W1, SCRATCH_W1 + 1, SCRATCH_W2, SCRATCH_W2 + 1))
+                }
+                ZeropageType.DONTUSE -> {
+                    free.clear() // don't use zeropage at all
+                }
+                else -> throw CompilerException("for this machine target, zero page type 'floatsafe' is not available. ${options.zeropage}")
+            }
+
+            require(SCRATCH_B1 !in free)
+            require(SCRATCH_REG !in free)
+            require(SCRATCH_W1 !in free)
+            require(SCRATCH_W2 !in free)
+
+            for (reserved in options.zpReserved)
+                reserve(reserved)
+        }
+    }
+}

compiler/src/prog8/functions/BuiltinFunctions.kt

@@ -3,97 +3,180 @@ package prog8.functions
 import prog8.ast.Program
 import prog8.ast.base.*
 import prog8.ast.expressions.*
+import prog8.ast.statements.StructDecl
+import prog8.ast.statements.VarDecl
 import prog8.compiler.CompilerException
 import kotlin.math.*
 
 
-class BuiltinFunctionParam(val name: String, val possibleDatatypes: Set<DataType>)
+class FParam(val name: String, val possibleDatatypes: Set<DataType>)
 
 
 typealias ConstExpressionCaller = (args: List<Expression>, position: Position, program: Program) -> NumericLiteralValue
 
 
-class FunctionSignature(val pure: Boolean,      // does it have side effects?
-                        val parameters: List<BuiltinFunctionParam>,
-                        val returntype: DataType?,
-                        val constExpressionFunc: ConstExpressionCaller? = null)
+class ReturnConvention(val dt: DataType, val reg: RegisterOrPair?, val floatFac1: Boolean)
+class ParamConvention(val dt: DataType, val reg: RegisterOrPair?, val variable: Boolean)
+class CallConvention(val params: List<ParamConvention>, val returns: ReturnConvention) {
+    override fun toString(): String {
+        val paramConvs =  params.mapIndexed { index, it ->
+            when {
+                it.reg!=null -> "$index:${it.reg}"
+                it.variable -> "$index:variable"
+                else -> "$index:???"
+            }
+        }
+        val returnConv =
+                when {
+                    returns.reg!=null -> returns.reg.toString()
+                    returns.floatFac1 -> "floatFAC1"
+                    else -> "<no returnvalue>"
+                }
+        return "CallConvention[" + paramConvs.joinToString() + " ; returns: $returnConv]"
+    }
+}
 
 
-val BuiltinFunctions = mapOf(
+class FSignature(val name: String,
+                 val pure: Boolean,      // does it have side effects?
+                 val parameters: List<FParam>,
+                 val known_returntype: DataType?,     // specify return type if fixed, otherwise null if it depends on the arguments
+                 val constExpressionFunc: ConstExpressionCaller? = null) {
+
+    fun callConvention(actualParamTypes: List<DataType>): CallConvention {
+        val returns = when(known_returntype) {
+            DataType.UBYTE, DataType.BYTE -> ReturnConvention(known_returntype, RegisterOrPair.A, false)
+            DataType.UWORD, DataType.WORD -> ReturnConvention(known_returntype, RegisterOrPair.AY, false)
+            DataType.FLOAT -> ReturnConvention(known_returntype, null, true)
+            in PassByReferenceDatatypes -> ReturnConvention(known_returntype!!, RegisterOrPair.AY, false)
+            else -> {
+                val paramType = actualParamTypes.first()
+                if(pure)
+                    // return type depends on arg type
+                    when(paramType) {
+                        DataType.UBYTE, DataType.BYTE -> ReturnConvention(paramType, RegisterOrPair.A, false)
+                        DataType.UWORD, DataType.WORD -> ReturnConvention(paramType, RegisterOrPair.AY, false)
+                        DataType.FLOAT -> ReturnConvention(paramType, null, true)
+                        in PassByReferenceDatatypes -> ReturnConvention(paramType, RegisterOrPair.AY, false)
+                        else -> ReturnConvention(paramType, null, false)
+                    }
+                else {
+                    ReturnConvention(paramType, null, false)
+                }
+            }
+        }
+        return when {
+            actualParamTypes.isEmpty() -> CallConvention(emptyList(), returns)
+            actualParamTypes.size==1 -> {
+                // one parameter? via register/registerpair
+                val paramConv = when(val paramType = actualParamTypes[0]) {
+                    DataType.UBYTE, DataType.BYTE -> ParamConvention(paramType, RegisterOrPair.A, false)
+                    DataType.UWORD, DataType.WORD -> ParamConvention(paramType, RegisterOrPair.AY, false)
+                    DataType.FLOAT -> ParamConvention(paramType, RegisterOrPair.AY, false)
+                    in PassByReferenceDatatypes -> ParamConvention(paramType, RegisterOrPair.AY, false)
+                    else -> ParamConvention(paramType, null, false)
+                }
+                CallConvention(listOf(paramConv), returns)
+            }
+            else -> {
+                // multiple parameters? via variables
+                val paramConvs = actualParamTypes.map { ParamConvention(it, null, true) }
+                CallConvention(paramConvs, returns)
+            }
+        }
+    }
+}
+
+private val functionSignatures: List<FSignature> = listOf(
         // this set of function have no return value and operate in-place:
-    "rol"         to FunctionSignature(false, listOf(BuiltinFunctionParam("item", setOf(DataType.UBYTE, DataType.UWORD))), null),
-    "ror"         to FunctionSignature(false, listOf(BuiltinFunctionParam("item", setOf(DataType.UBYTE, DataType.UWORD))), null),
-    "rol2"        to FunctionSignature(false, listOf(BuiltinFunctionParam("item", setOf(DataType.UBYTE, DataType.UWORD))), null),
-    "ror2"        to FunctionSignature(false, listOf(BuiltinFunctionParam("item", setOf(DataType.UBYTE, DataType.UWORD))), null),
-    "lsl"         to FunctionSignature(false, listOf(BuiltinFunctionParam("item", IntegerDatatypes)), null),
-    "lsr"         to FunctionSignature(false, listOf(BuiltinFunctionParam("item", IntegerDatatypes)), null),
-    "sort"        to FunctionSignature(false, listOf(BuiltinFunctionParam("array", ArrayDatatypes)), null),
-    "reverse"     to FunctionSignature(false, listOf(BuiltinFunctionParam("array", ArrayDatatypes)), null),
+    FSignature("rol"         , false, listOf(FParam("item", setOf(DataType.UBYTE, DataType.UWORD))), null),
+    FSignature("ror"         , false, listOf(FParam("item", setOf(DataType.UBYTE, DataType.UWORD))), null),
+    FSignature("rol2"        , false, listOf(FParam("item", setOf(DataType.UBYTE, DataType.UWORD))), null),
+    FSignature("ror2"        , false, listOf(FParam("item", setOf(DataType.UBYTE, DataType.UWORD))), null),
+    FSignature("sort"        , false, listOf(FParam("array", ArrayDatatypes)), null),
+    FSignature("reverse"     , false, listOf(FParam("array", ArrayDatatypes)), null),
         // these few have a return value depending on the argument(s):
-    "max"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArg(a, p, prg, ::builtinMax) },    // type depends on args
-    "min"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArg(a, p, prg, ::builtinMin) },    // type depends on args
-    "sum"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArg(a, p, prg, ::builtinSum) },      // type depends on args
-    "abs"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", NumericDatatypes)), null, ::builtinAbs),      // type depends on argument
-    "len"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", IterableDatatypes)), null, ::builtinLen),    // type is UBYTE or UWORD depending on actual length
+    FSignature("max"         , true, listOf(FParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArg(a, p, prg, ::builtinMax) },    // type depends on args
+    FSignature("min"         , true, listOf(FParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArg(a, p, prg, ::builtinMin) },    // type depends on args
+    FSignature("sum"         , true, listOf(FParam("values", ArrayDatatypes)), null) { a, p, prg -> collectionArg(a, p, prg, ::builtinSum) },      // type depends on args
+    FSignature("abs"         , true, listOf(FParam("value", NumericDatatypes)), null, ::builtinAbs),      // type depends on argument
+    FSignature("len"         , true, listOf(FParam("values", IterableDatatypes)), null, ::builtinLen),    // type is UBYTE or UWORD depending on actual length
+    FSignature("sizeof"      , true, listOf(FParam("object", DataType.values().toSet())), DataType.UBYTE, ::builtinSizeof),
         // normal functions follow:
-    "sgn"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", NumericDatatypes)), DataType.BYTE, ::builtinSgn ),
-    "sin"         to FunctionSignature(true, listOf(BuiltinFunctionParam("rads", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::sin) },
-    "sin8"        to FunctionSignature(true, listOf(BuiltinFunctionParam("angle8", setOf(DataType.UBYTE))), DataType.BYTE, ::builtinSin8 ),
-    "sin8u"       to FunctionSignature(true, listOf(BuiltinFunctionParam("angle8", setOf(DataType.UBYTE))), DataType.UBYTE, ::builtinSin8u ),
-    "sin16"       to FunctionSignature(true, listOf(BuiltinFunctionParam("angle8", setOf(DataType.UBYTE))), DataType.WORD, ::builtinSin16 ),
-    "sin16u"      to FunctionSignature(true, listOf(BuiltinFunctionParam("angle8", setOf(DataType.UBYTE))), DataType.UWORD, ::builtinSin16u ),
-    "cos"         to FunctionSignature(true, listOf(BuiltinFunctionParam("rads", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::cos) },
-    "cos8"        to FunctionSignature(true, listOf(BuiltinFunctionParam("angle8", setOf(DataType.UBYTE))), DataType.BYTE, ::builtinCos8 ),
-    "cos8u"       to FunctionSignature(true, listOf(BuiltinFunctionParam("angle8", setOf(DataType.UBYTE))), DataType.UBYTE, ::builtinCos8u ),
-    "cos16"       to FunctionSignature(true, listOf(BuiltinFunctionParam("angle8", setOf(DataType.UBYTE))), DataType.WORD, ::builtinCos16 ),
-    "cos16u"      to FunctionSignature(true, listOf(BuiltinFunctionParam("angle8", setOf(DataType.UBYTE))), DataType.UWORD, ::builtinCos16u ),
-    "tan"         to FunctionSignature(true, listOf(BuiltinFunctionParam("rads", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::tan) },
-    "atan"        to FunctionSignature(true, listOf(BuiltinFunctionParam("rads", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::atan) },
-    "ln"          to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::log) },
-    "log2"        to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, ::log2) },
-    "sqrt16"      to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.UWORD))), DataType.UBYTE) { a, p, prg -> oneIntArgOutputInt(a, p, prg) { sqrt(it.toDouble()).toInt() } },
-    "sqrt"        to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::sqrt) },
-    "rad"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::toRadians) },
-    "deg"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::toDegrees) },
-    "round"       to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArgOutputWord(a, p, prg, Math::round) },
-    "floor"       to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArgOutputWord(a, p, prg, Math::floor) },
-    "ceil"        to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArgOutputWord(a, p, prg, Math::ceil) },
-    "any"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), DataType.UBYTE) { a, p, prg -> collectionArg(a, p, prg, ::builtinAny) },
-    "all"         to FunctionSignature(true, listOf(BuiltinFunctionParam("values", ArrayDatatypes)), DataType.UBYTE) { a, p, prg -> collectionArg(a, p, prg, ::builtinAll) },
-    "lsb"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.UWORD, DataType.WORD))), DataType.UBYTE) { a, p, prg -> oneIntArgOutputInt(a, p, prg) { x: Int -> x and 255 }},
-    "msb"         to FunctionSignature(true, listOf(BuiltinFunctionParam("value", setOf(DataType.UWORD, DataType.WORD))), DataType.UBYTE) { a, p, prg -> oneIntArgOutputInt(a, p, prg) { x: Int -> x ushr 8 and 255}},
-    "mkword"      to FunctionSignature(true, listOf(
-                                                        BuiltinFunctionParam("lsb", setOf(DataType.UBYTE)),
-                                                        BuiltinFunctionParam("msb", setOf(DataType.UBYTE))), DataType.UWORD, ::builtinMkword),
-    "rnd"         to FunctionSignature(true, emptyList(), DataType.UBYTE),
-    "rndw"        to FunctionSignature(true, emptyList(), DataType.UWORD),
-    "rndf"        to FunctionSignature(true, emptyList(), DataType.FLOAT),
-    "rsave"       to FunctionSignature(false, emptyList(), null),
-    "rrestore"    to FunctionSignature(false, emptyList(), null),
-    "set_carry"   to FunctionSignature(false, emptyList(), null),
-    "clear_carry" to FunctionSignature(false, emptyList(), null),
-    "set_irqd"    to FunctionSignature(false, emptyList(), null),
-    "clear_irqd"  to FunctionSignature(false, emptyList(), null),
-    "read_flags"  to FunctionSignature(false, emptyList(), DataType.UBYTE),
-    "swap"        to FunctionSignature(false, listOf(BuiltinFunctionParam("first", NumericDatatypes), BuiltinFunctionParam("second", NumericDatatypes)), null),
-    "memcopy"     to FunctionSignature(false, listOf(
-                                                        BuiltinFunctionParam("from", IterableDatatypes + DataType.UWORD),
-                                                        BuiltinFunctionParam("to", IterableDatatypes + DataType.UWORD),
-                                                        BuiltinFunctionParam("numbytes", setOf(DataType.UBYTE))), null),
-    "memset"      to FunctionSignature(false, listOf(
-                                                        BuiltinFunctionParam("address", IterableDatatypes + DataType.UWORD),
-                                                        BuiltinFunctionParam("numbytes", setOf(DataType.UWORD)),
-                                                        BuiltinFunctionParam("bytevalue", ByteDatatypes)), null),
-    "memsetw"     to FunctionSignature(false, listOf(
-                                                        BuiltinFunctionParam("address", IterableDatatypes + DataType.UWORD),
-                                                        BuiltinFunctionParam("numwords", setOf(DataType.UWORD)),
-                                                        BuiltinFunctionParam("wordvalue", setOf(DataType.UWORD, DataType.WORD))), null),
-    "strlen"      to FunctionSignature(true, listOf(BuiltinFunctionParam("string", setOf(DataType.STR))), DataType.UBYTE, ::builtinStrlen)
+    FSignature("sgn"         , true, listOf(FParam("value", NumericDatatypes)), DataType.BYTE, ::builtinSgn ),
+    FSignature("sin"         , true, listOf(FParam("rads", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::sin) },
+    FSignature("sin8"        , true, listOf(FParam("angle8", setOf(DataType.UBYTE))), DataType.BYTE, ::builtinSin8 ),
+    FSignature("sin8u"       , true, listOf(FParam("angle8", setOf(DataType.UBYTE))), DataType.UBYTE, ::builtinSin8u ),
+    FSignature("sin16"       , true, listOf(FParam("angle8", setOf(DataType.UBYTE))), DataType.WORD, ::builtinSin16 ),
+    FSignature("sin16u"      , true, listOf(FParam("angle8", setOf(DataType.UBYTE))), DataType.UWORD, ::builtinSin16u ),
+    FSignature("cos"         , true, listOf(FParam("rads", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::cos) },
+    FSignature("cos8"        , true, listOf(FParam("angle8", setOf(DataType.UBYTE))), DataType.BYTE, ::builtinCos8 ),
+    FSignature("cos8u"       , true, listOf(FParam("angle8", setOf(DataType.UBYTE))), DataType.UBYTE, ::builtinCos8u ),
+    FSignature("cos16"       , true, listOf(FParam("angle8", setOf(DataType.UBYTE))), DataType.WORD, ::builtinCos16 ),
+    FSignature("cos16u"      , true, listOf(FParam("angle8", setOf(DataType.UBYTE))), DataType.UWORD, ::builtinCos16u ),
+    FSignature("tan"         , true, listOf(FParam("rads", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::tan) },
+    FSignature("atan"        , true, listOf(FParam("rads", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::atan) },
+    FSignature("ln"          , true, listOf(FParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::log) },
+    FSignature("log2"        , true, listOf(FParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, ::log2) },
+    FSignature("sqrt16"      , true, listOf(FParam("value", setOf(DataType.UWORD))), DataType.UBYTE) { a, p, prg -> oneIntArgOutputInt(a, p, prg) { sqrt(it.toDouble()).toInt() } },
+    FSignature("sqrt"        , true, listOf(FParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::sqrt) },
+    FSignature("rad"         , true, listOf(FParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::toRadians) },
+    FSignature("deg"         , true, listOf(FParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArg(a, p, prg, Math::toDegrees) },
+    FSignature("round"       , true, listOf(FParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArgOutputWord(a, p, prg, Math::round) },
+    FSignature("floor"       , true, listOf(FParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArgOutputWord(a, p, prg, Math::floor) },
+    FSignature("ceil"        , true, listOf(FParam("value", setOf(DataType.FLOAT))), DataType.FLOAT) { a, p, prg -> oneDoubleArgOutputWord(a, p, prg, Math::ceil) },
+    FSignature("any"         , true, listOf(FParam("values", ArrayDatatypes)), DataType.UBYTE) { a, p, prg -> collectionArg(a, p, prg, ::builtinAny) },
+    FSignature("all"         , true, listOf(FParam("values", ArrayDatatypes)), DataType.UBYTE) { a, p, prg -> collectionArg(a, p, prg, ::builtinAll) },
+    FSignature("lsb"         , true, listOf(FParam("value", setOf(DataType.UWORD, DataType.WORD))), DataType.UBYTE) { a, p, prg -> oneIntArgOutputInt(a, p, prg) { x: Int -> x and 255 }},
+    FSignature("msb"         , true, listOf(FParam("value", setOf(DataType.UWORD, DataType.WORD))), DataType.UBYTE) { a, p, prg -> oneIntArgOutputInt(a, p, prg) { x: Int -> x ushr 8 and 255}},
+    FSignature("mkword"      , true, listOf(FParam("msb", setOf(DataType.UBYTE)), FParam("lsb", setOf(DataType.UBYTE))), DataType.UWORD, ::builtinMkword),
+    FSignature("rnd"         , false, emptyList(), DataType.UBYTE),
+    FSignature("rndw"        , false, emptyList(), DataType.UWORD),
+    FSignature("rndf"        , false, emptyList(), DataType.FLOAT),
+    FSignature("exit"        , false, listOf(FParam("returnvalue", setOf(DataType.UBYTE))), null),
+    FSignature("rsave"       , false, emptyList(), null),
+    FSignature("rrestore"    , false, emptyList(), null),
+    FSignature("set_carry"   , false, emptyList(), null),
+    FSignature("clear_carry" , false, emptyList(), null),
+    FSignature("set_irqd"    , false, emptyList(), null),
+    FSignature("clear_irqd"  , false, emptyList(), null),
+    FSignature("read_flags"  , false, emptyList(), DataType.UBYTE),
+    FSignature("swap"        , false, listOf(FParam("first", NumericDatatypes), FParam("second", NumericDatatypes)), null),
+    FSignature("memcopy"     , false, listOf(
+                            FParam("from", IterableDatatypes + DataType.UWORD),
+                            FParam("to", IterableDatatypes + DataType.UWORD),
+                            FParam("numbytes", setOf(DataType.UBYTE, DataType.UWORD))), null),
+    FSignature("memset"      , false, listOf(
+                            FParam("address", IterableDatatypes + DataType.UWORD),
+                            FParam("numbytes", setOf(DataType.UWORD)),
+                            FParam("bytevalue", ByteDatatypes)), null),
+    FSignature("memsetw"     , false, listOf(
+                            FParam("address", IterableDatatypes + DataType.UWORD),
+                            FParam("numwords", setOf(DataType.UWORD)),
+                            FParam("wordvalue", setOf(DataType.UWORD, DataType.WORD))), null),
+    FSignature("strlen"      , true, listOf(FParam("string", setOf(DataType.STR))), DataType.UBYTE, ::builtinStrlen),
+    FSignature("substr"      , false, listOf(
+            FParam("source", IterableDatatypes + DataType.UWORD),
+            FParam("target", IterableDatatypes + DataType.UWORD),
+            FParam("start", setOf(DataType.UBYTE)),
+            FParam("length", setOf(DataType.UBYTE))), null),
+    FSignature("leftstr"     , false, listOf(
+            FParam("source", IterableDatatypes + DataType.UWORD),
+            FParam("target", IterableDatatypes + DataType.UWORD),
+            FParam("length", setOf(DataType.UBYTE))), null),
+    FSignature("rightstr"    , false, listOf(
+            FParam("source", IterableDatatypes + DataType.UWORD),
+            FParam("target", IterableDatatypes + DataType.UWORD),
+            FParam("length", setOf(DataType.UBYTE))), null),
+    FSignature("strcmp"      , false, listOf(FParam("s1", IterableDatatypes + DataType.UWORD), FParam("s2", IterableDatatypes + DataType.UWORD)), DataType.BYTE, null)
 )
 
-fun builtinMax(array: List<Number>): Number = array.maxBy { it.toDouble() }!!
+val BuiltinFunctions = functionSignatures.associateBy { it.name }
 
-fun builtinMin(array: List<Number>): Number = array.minBy { it.toDouble() }!!
+
+fun builtinMax(array: List<Number>): Number = array.maxByOrNull { it.toDouble() }!!
+
+fun builtinMin(array: List<Number>): Number = array.minByOrNull { it.toDouble() }!!
 
 fun builtinSum(array: List<Number>): Number = array.sumByDouble { it.toDouble() }
 
@@ -130,17 +213,17 @@ fun builtinFunctionReturnType(function: String, args: List<Expression>, program:
     }
 
     val func = BuiltinFunctions.getValue(function)
-    if(func.returntype!=null)
-        return InferredTypes.knownFor(func.returntype)
-    // function has return values, but the return type depends on the arguments
+    if(func.known_returntype!=null)
+        return InferredTypes.knownFor(func.known_returntype)
 
+    // function has return values, but the return type depends on the arguments
     return when (function) {
         "abs" -> {
             val dt = args.single().inferType(program)
-            if(dt.typeOrElse(DataType.STRUCT) in NumericDatatypes)
-                return dt
+            return if(dt.typeOrElse(DataType.STRUCT) in NumericDatatypes)
+                dt
             else
-                throw FatalAstException("weird datatype passed to abs $dt")
+                InferredTypes.InferredType.unknown()
         }
         "max", "min" -> {
             when(val dt = datatypeFromIterableArg(args.single())) {
@@ -173,6 +256,7 @@ fun builtinFunctionReturnType(function: String, args: List<Expression>, program:
 
 
 class NotConstArgumentException: AstException("not a const argument to a built-in function")
+class CannotEvaluateException(func:String, msg: String): FatalAstException("cannot evaluate built-in function $func: $msg")
 
 
 private fun oneDoubleArg(args: List<Expression>, position: Position, program: Program, function: (arg: Double)->Number): NumericLiteralValue {
@@ -227,54 +311,88 @@ private fun builtinAbs(args: List<Expression>, position: Position, program: Prog
     }
 }
 
+private fun builtinSizeof(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
+    // 1 arg, type = anything, result type = ubyte
+    if(args.size!=1)
+        throw SyntaxError("sizeof requires one argument", position)
+    if(args[0] !is IdentifierReference)
+        throw SyntaxError("sizeof argument should be an identifier", position)
+
+    val dt = args[0].inferType(program)
+    if(dt.isKnown) {
+        val target = (args[0] as IdentifierReference).targetStatement(program.namespace)
+                ?: throw CannotEvaluateException("sizeof", "no target")
+
+        fun structSize(target: StructDecl) =
+                NumericLiteralValue(DataType.UBYTE, target.statements.map { (it as VarDecl).datatype.memorySize() }.sum(), position)
+
+        return when {
+            dt.typeOrElse(DataType.STRUCT) in ArrayDatatypes -> {
+                val length = (target as VarDecl).arraysize!!.constIndex() ?: throw CannotEvaluateException("sizeof", "unknown array size")
+                val elementDt = ArrayElementTypes.getValue(dt.typeOrElse(DataType.STRUCT))
+                numericLiteral(elementDt.memorySize() * length, position)
+            }
+            dt.istype(DataType.STRUCT) -> {
+                when (target) {
+                    is VarDecl -> structSize(target.struct!!)
+                    is StructDecl -> structSize(target)
+                    else -> throw CompilerException("weird struct type $target")
+                }
+            }
+            dt.istype(DataType.STR) -> throw SyntaxError("sizeof str is undefined, did you mean len?", position)
+            else -> NumericLiteralValue(DataType.UBYTE, dt.typeOrElse(DataType.STRUCT).memorySize(), position)
+        }
+    } else {
+        throw SyntaxError("sizeof invalid argument type", position)
+    }
+}
+
 private fun builtinStrlen(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 1)
         throw SyntaxError("strlen requires one argument", position)
-    val argument = args[0].constValue(program) ?: throw NotConstArgumentException()
-    if(argument.type != DataType.STR)
-        throw SyntaxError("strlen must have string argument", position)
-
-    throw NotConstArgumentException()       // this function is not considering the string argument a constant
+    val argument=args[0]
+    if(argument is StringLiteralValue)
+        return NumericLiteralValue.optimalInteger(argument.value.length, argument.position)
+    val vardecl = (argument as IdentifierReference).targetVarDecl(program.namespace)
+    if(vardecl!=null) {
+        if(vardecl.datatype!=DataType.STR && vardecl.datatype!=DataType.UWORD)
+            throw SyntaxError("strlen must have string argument", position)
+        if(vardecl.autogeneratedDontRemove && vardecl.value!=null) {
+            return NumericLiteralValue.optimalInteger((vardecl.value as StringLiteralValue).value.length, argument.position)
+        }
+    }
+    throw NotConstArgumentException()
 }
 
 private fun builtinLen(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     // note: in some cases the length is > 255 and then we have to return a UWORD type instead of a UBYTE.
     if(args.size!=1)
         throw SyntaxError("len requires one argument", position)
-    val constArg = args[0].constValue(program)
-    if(constArg!=null)
-        throw SyntaxError("len of weird argument ${args[0]}", position)
 
     val directMemVar = ((args[0] as? DirectMemoryRead)?.addressExpression as? IdentifierReference)?.targetVarDecl(program.namespace)
-    var arraySize = directMemVar?.arraysize?.size()
+    var arraySize = directMemVar?.arraysize?.constIndex()
     if(arraySize != null)
         return NumericLiteralValue.optimalInteger(arraySize, position)
     if(args[0] is ArrayLiteralValue)
         return NumericLiteralValue.optimalInteger((args[0] as ArrayLiteralValue).value.size, position)
     if(args[0] !is IdentifierReference)
-        throw SyntaxError("len argument should be an identifier, but is ${args[0]}", position)
-    val target = (args[0] as IdentifierReference).targetVarDecl(program.namespace)!!
+        throw SyntaxError("len argument should be an identifier", position)
+    val target = (args[0] as IdentifierReference).targetVarDecl(program.namespace)
+            ?: throw CannotEvaluateException("len", "no target vardecl")
 
     return when(target.datatype) {
-        DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W -> {
-            arraySize = target.arraysize!!.size()!!
-            if(arraySize>256)
-                throw CompilerException("array length exceeds byte limit ${target.position}")
-            NumericLiteralValue.optimalInteger(arraySize, args[0].position)
-        }
-        DataType.ARRAY_F -> {
-            arraySize = target.arraysize!!.size()!!
-            if(arraySize>256)
-                throw CompilerException("array length exceeds byte limit ${target.position}")
+        DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W, DataType.ARRAY_F -> {
+            arraySize = target.arraysize?.constIndex()
+            if(arraySize==null)
+                throw CannotEvaluateException("len", "arraysize unknown")
             NumericLiteralValue.optimalInteger(arraySize, args[0].position)
         }
         DataType.STR -> {
             val refLv = target.value as StringLiteralValue
-            if(refLv.value.length>255)
-                throw CompilerException("string length exceeds byte limit ${refLv.position}")
             NumericLiteralValue.optimalInteger(refLv.value.length, args[0].position)
         }
-        in NumericDatatypes -> throw SyntaxError("len of weird argument ${args[0]}", position)
+        DataType.STRUCT -> throw SyntaxError("cannot use len on struct, did you mean sizeof?", args[0].position)
+        in NumericDatatypes -> throw SyntaxError("cannot use len on numeric value, did you mean sizeof?", args[0].position)
         else -> throw CompilerException("weird datatype")
     }
 }
@@ -282,9 +400,9 @@ private fun builtinLen(args: List<Expression>, position: Position, program: Prog
 
 private fun builtinMkword(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
     if (args.size != 2)
-        throw SyntaxError("mkword requires lsb and msb arguments", position)
-    val constLsb = args[0].constValue(program) ?: throw NotConstArgumentException()
-    val constMsb = args[1].constValue(program) ?: throw NotConstArgumentException()
+        throw SyntaxError("mkword requires msb and lsb arguments", position)
+    val constMsb = args[0].constValue(program) ?: throw NotConstArgumentException()
+    val constLsb = args[1].constValue(program) ?: throw NotConstArgumentException()
     val result = (constMsb.number.toInt() shl 8) or constLsb.number.toInt()
     return NumericLiteralValue(DataType.UWORD, result, position)
 }
@@ -294,7 +412,7 @@ private fun builtinSin8(args: List<Expression>, position: Position, program: Pro
         throw SyntaxError("sin8 requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
     val rad = constval.number.toDouble() /256.0 * 2.0 * PI
-    return NumericLiteralValue(DataType.BYTE, (127.0 * sin(rad)).toShort(), position)
+    return NumericLiteralValue(DataType.BYTE, (127.0 * sin(rad)).toInt().toShort(), position)
 }
 
 private fun builtinSin8u(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
@@ -302,7 +420,7 @@ private fun builtinSin8u(args: List<Expression>, position: Position, program: Pr
         throw SyntaxError("sin8u requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
     val rad = constval.number.toDouble() /256.0 * 2.0 * PI
-    return NumericLiteralValue(DataType.UBYTE, (128.0 + 127.5 * sin(rad)).toShort(), position)
+    return NumericLiteralValue(DataType.UBYTE, (128.0 + 127.5 * sin(rad)).toInt().toShort(), position)
 }
 
 private fun builtinCos8(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
@@ -310,7 +428,7 @@ private fun builtinCos8(args: List<Expression>, position: Position, program: Pro
         throw SyntaxError("cos8 requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
     val rad = constval.number.toDouble() /256.0 * 2.0 * PI
-    return NumericLiteralValue(DataType.BYTE, (127.0 * cos(rad)).toShort(), position)
+    return NumericLiteralValue(DataType.BYTE, (127.0 * cos(rad)).toInt().toShort(), position)
 }
 
 private fun builtinCos8u(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
@@ -318,7 +436,7 @@ private fun builtinCos8u(args: List<Expression>, position: Position, program: Pr
         throw SyntaxError("cos8u requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
     val rad = constval.number.toDouble() /256.0 * 2.0 * PI
-    return NumericLiteralValue(DataType.UBYTE, (128.0 + 127.5 * cos(rad)).toShort(), position)
+    return NumericLiteralValue(DataType.UBYTE, (128.0 + 127.5 * cos(rad)).toInt().toShort(), position)
 }
 
 private fun builtinSin16(args: List<Expression>, position: Position, program: Program): NumericLiteralValue {
@@ -357,7 +475,7 @@ private fun builtinSgn(args: List<Expression>, position: Position, program: Prog
     if (args.size != 1)
         throw SyntaxError("sgn requires one argument", position)
     val constval = args[0].constValue(program) ?: throw NotConstArgumentException()
-    return NumericLiteralValue(DataType.BYTE, constval.number.toDouble().sign.toShort(), position)
+    return NumericLiteralValue(DataType.BYTE, constval.number.toDouble().sign.toInt().toShort(), position)
 }
 
 private fun numericLiteral(value: Number, position: Position): NumericLiteralValue {
@@ -369,8 +487,8 @@ private fun numericLiteral(value: Number, position: Position): NumericLiteralVal
                 floatNum
 
     return when(tweakedValue) {
-        is Int -> NumericLiteralValue.optimalNumeric(value.toInt(), position)
-        is Short -> NumericLiteralValue.optimalNumeric(value.toInt(), position)
+        is Int -> NumericLiteralValue.optimalInteger(value.toInt(), position)
+        is Short -> NumericLiteralValue.optimalInteger(value.toInt(), position)
         is Byte -> NumericLiteralValue(DataType.UBYTE, value.toShort(), position)
         is Double -> NumericLiteralValue(DataType.FLOAT, value.toDouble(), position)
         is Float -> NumericLiteralValue(DataType.FLOAT, value.toDouble(), position)

compiler/src/prog8/optimizer/BinExprSplitter.kt

@@ -0,0 +1,87 @@
+package prog8.optimizer
+
+import prog8.ast.INameScope
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.expressions.*
+import prog8.ast.processing.AstWalker
+import prog8.ast.processing.IAstModification
+import prog8.ast.statements.AssignTarget
+import prog8.ast.statements.Assignment
+
+
+internal class BinExprSplitter(private val program: Program) : AstWalker() {
+    private val noModifications = emptyList<IAstModification>()
+
+//    override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
+// TODO somehow if we do this, the resulting code for some programs (cube3d.p8) gets hundreds of bytes larger...:
+//        if(decl.type==VarDeclType.VAR ) {
+//            val binExpr = decl.value as? BinaryExpression
+//            if (binExpr != null && binExpr.operator in augmentAssignmentOperators) {
+//                // split into a vardecl with just the left expression, and an aug. assignment with the right expression.
+//                val augExpr = BinaryExpression(IdentifierReference(listOf(decl.name), decl.position), binExpr.operator, binExpr.right, binExpr.position)
+//                val target = AssignTarget(IdentifierReference(listOf(decl.name), decl.position), null, null, decl.position)
+//                val assign = Assignment(target, augExpr, binExpr.position)
+//                println("SPLIT VARDECL $decl")
+//                return listOf(
+//                        IAstModification.SetExpression({ decl.value = it }, binExpr.left, decl),
+//                        IAstModification.InsertAfter(decl, assign, parent)
+//                )
+//            }
+//        }
+//        return noModifications
+//    }
+
+    override fun after(assignment: Assignment, parent: Node): Iterable<IAstModification> {
+
+        val binExpr = assignment.value as? BinaryExpression
+        if (binExpr != null) {
+/*
+
+Reduce the complexity of a (binary) expression that has to be evaluated on the eval stack,
+by attempting to splitting it up into individual simple steps.
+We only consider a binary expression *one* level deep (so the operands must not be a combined expression)
+
+
+X =      BinExpr                                    X   =   LeftExpr
+        <operator>                                     followed by
+          /   \             IF 'X' not used         X   =   BinExpr
+         /     \             IN expression ==>             <operator>
+        /       \                                           /   \
+    LeftExpr.  RightExpr.                                  /     \
+                                                          X     RightExpr.
+
+
+ */
+            if(binExpr.operator in augmentAssignmentOperators && isSimpleTarget(assignment.target, program.namespace)) {
+                if(assignment.target isSameAs binExpr.left || assignment.target isSameAs binExpr.right)
+                    return noModifications
+
+                if(isSimpleExpression(binExpr.right) && !assignment.isAugmentable) {
+                    val firstAssign = Assignment(assignment.target, binExpr.left, binExpr.left.position)
+                    val targetExpr = assignment.target.toExpression()
+                    val augExpr = BinaryExpression(targetExpr, binExpr.operator, binExpr.right, binExpr.right.position)
+                    return listOf(
+                            IAstModification.InsertBefore(assignment, firstAssign, assignment.definingScope()),
+                            IAstModification.ReplaceNode(assignment.value, augExpr, assignment))
+                }
+            }
+
+            // TODO further unraveling of binary expression trees into flat statements.
+            // however this should probably be done in a more generic way to also service
+            // the expressiontrees that are not used in an assignment statement...
+        }
+
+        return noModifications
+    }
+
+    private fun isSimpleExpression(expr: Expression) =
+            expr is IdentifierReference || expr is NumericLiteralValue || expr is AddressOf || expr is DirectMemoryRead || expr is StringLiteralValue || expr is ArrayLiteralValue || expr is RangeExpr
+
+    private fun isSimpleTarget(target: AssignTarget, namespace: INameScope) =
+            if (target.identifier!=null || target.memoryAddress!=null)
+                target.isInRegularRAM(namespace)
+            else
+                false
+
+}

compiler/src/prog8/optimizer/CallGraph.kt

@@ -1,27 +1,33 @@
 package prog8.optimizer
 
-import prog8.ast.INameScope
-import prog8.ast.Module
-import prog8.ast.Node
-import prog8.ast.Program
+import prog8.ast.*
 import prog8.ast.base.DataType
+import prog8.ast.base.ErrorReporter
 import prog8.ast.base.ParentSentinel
-import prog8.ast.base.VarDeclType
-import prog8.ast.base.initvarsSubName
+import prog8.ast.base.Position
 import prog8.ast.expressions.FunctionCall
 import prog8.ast.expressions.IdentifierReference
 import prog8.ast.processing.IAstVisitor
 import prog8.ast.statements.*
 import prog8.compiler.loadAsmIncludeFile
 
+private val alwaysKeepSubroutines = setOf(
+        Pair("main", "start"),
+        Pair("irq", "irq")
+)
 
-class CallGraph(private val program: Program): IAstVisitor {
+private val asmJumpRx = Regex("""[\-+a-zA-Z0-9_ \t]+(jmp|jsr)[ \t]+(\S+).*""", RegexOption.IGNORE_CASE)
+private val asmRefRx = Regex("""[\-+a-zA-Z0-9_ \t]+(...)[ \t]+(\S+).*""", RegexOption.IGNORE_CASE)
 
-    val modulesImporting = mutableMapOf<Module, List<Module>>().withDefault { mutableListOf() }
-    val modulesImportedBy = mutableMapOf<Module, List<Module>>().withDefault { mutableListOf() }
-    val subroutinesCalling = mutableMapOf<INameScope, List<Subroutine>>().withDefault { mutableListOf() }
-    val subroutinesCalledBy = mutableMapOf<Subroutine, List<Node>>().withDefault { mutableListOf() }
-    // TODO  add dataflow graph: what statements use what variables
+
+class CallGraph(private val program: Program) : IAstVisitor {
+
+    val imports = mutableMapOf<Module, List<Module>>().withDefault { mutableListOf() }
+    val importedBy = mutableMapOf<Module, List<Module>>().withDefault { mutableListOf() }
+    val calls = mutableMapOf<Subroutine, List<Subroutine>>().withDefault { mutableListOf() }
+    val calledBy = mutableMapOf<Subroutine, List<Node>>().withDefault { mutableListOf() }
+
+    // TODO  add dataflow graph: what statements use what variables - can be used to eliminate unused vars
     val usedSymbols = mutableSetOf<Statement>()
 
     init {
@@ -31,9 +37,9 @@ class CallGraph(private val program: Program): IAstVisitor {
     fun forAllSubroutines(scope: INameScope, sub: (s: Subroutine) -> Unit) {
         fun findSubs(scope: INameScope) {
             scope.statements.forEach {
-                if(it is Subroutine)
+                if (it is Subroutine)
                     sub(it)
-                if(it is INameScope)
+                if (it is INameScope)
                     findSubs(it)
             }
         }
@@ -47,17 +53,8 @@ class CallGraph(private val program: Program): IAstVisitor {
             it.importedBy.clear()
             it.imports.clear()
 
-            it.importedBy.addAll(modulesImportedBy.getValue(it))
-            it.imports.addAll(modulesImporting.getValue(it))
-
-            forAllSubroutines(it) { sub ->
-                sub.calledBy.clear()
-                sub.calls.clear()
-
-                sub.calledBy.addAll(subroutinesCalledBy.getValue(sub))
-                sub.calls.addAll(subroutinesCalling.getValue(sub))
-            }
-
+            it.importedBy.addAll(importedBy.getValue(it))
+            it.imports.addAll(imports.getValue(it))
         }
 
         val rootmodule = program.modules.first()
@@ -65,7 +62,7 @@ class CallGraph(private val program: Program): IAstVisitor {
     }
 
     override fun visit(block: Block) {
-        if(block.definingModule().isLibraryModule) {
+        if (block.definingModule().isLibraryModule) {
             // make sure the block is not removed
             addNodeAndParentScopes(block)
         }
@@ -75,14 +72,16 @@ class CallGraph(private val program: Program): IAstVisitor {
 
     override fun visit(directive: Directive) {
         val thisModule = directive.definingModule()
-        if(directive.directive=="%import") {
-            val importedModule: Module = program.modules.single { it.name==directive.args[0].name }
-            modulesImporting[thisModule] = modulesImporting.getValue(thisModule).plus(importedModule)
-            modulesImportedBy[importedModule] = modulesImportedBy.getValue(importedModule).plus(thisModule)
-        } else if (directive.directive=="%asminclude") {
+        if (directive.directive == "%import") {
+            val importedModule: Module = program.modules.single { it.name == directive.args[0].name }
+            imports[thisModule] = imports.getValue(thisModule).plus(importedModule)
+            importedBy[importedModule] = importedBy.getValue(importedModule).plus(thisModule)
+        } else if (directive.directive == "%asminclude") {
             val asm = loadAsmIncludeFile(directive.args[0].str!!, thisModule.source)
-            val scope = directive.definingScope()
-            scanAssemblyCode(asm, directive, scope)
+            val scope = directive.definingSubroutine()
+            if(scope!=null) {
+                scanAssemblyCode(asm, directive, scope)
+            }
         }
 
         super.visit(directive)
@@ -91,7 +90,7 @@ class CallGraph(private val program: Program): IAstVisitor {
     override fun visit(identifier: IdentifierReference) {
         // track symbol usage
         val target = identifier.targetStatement(this.program.namespace)
-        if(target!=null) {
+        if (target != null) {
             addNodeAndParentScopes(target)
         }
         super.visit(identifier)
@@ -99,24 +98,18 @@ class CallGraph(private val program: Program): IAstVisitor {
 
     private fun addNodeAndParentScopes(stmt: Statement) {
         usedSymbols.add(stmt)
-        var node: Node=stmt
+        var node: Node = stmt
         do {
-            if(node is INameScope && node is Statement) {
+            if (node is INameScope && node is Statement) {
                 usedSymbols.add(node)
             }
-            node=node.parent
+            node = node.parent
         } while (node !is Module && node !is ParentSentinel)
     }
 
     override fun visit(subroutine: Subroutine) {
-        val alwaysKeepSubroutines = setOf(
-                Pair("main", "start"),
-                Pair("irq", "irq"),
-                Pair("prog8_lib", "init_system")
-        )
-
-        if(Pair(subroutine.definingScope().name, subroutine.name) in alwaysKeepSubroutines
-                || subroutine.name== initvarsSubName || subroutine.definingModule().isLibraryModule) {
+        if (Pair(subroutine.definingScope().name, subroutine.name) in alwaysKeepSubroutines
+                || subroutine.definingModule().isLibraryModule) {
             // make sure the entrypoint is mentioned in the used symbols
             addNodeAndParentScopes(subroutine)
         }
@@ -124,12 +117,12 @@ class CallGraph(private val program: Program): IAstVisitor {
     }
 
     override fun visit(decl: VarDecl) {
-        if(decl.autogeneratedDontRemove || (decl.definingModule().isLibraryModule && decl.type!=VarDeclType.VAR)) {
-            // make sure autogenerated vardecls are in the used symbols
+        if (decl.autogeneratedDontRemove || decl.definingModule().isLibraryModule) {
+            // make sure autogenerated vardecls are in the used symbols and are never removed as 'unused'
             addNodeAndParentScopes(decl)
         }
 
-        if(decl.datatype==DataType.STRUCT)
+        if (decl.datatype == DataType.STRUCT)
             addNodeAndParentScopes(decl)
 
         super.visit(decl)
@@ -137,10 +130,10 @@ class CallGraph(private val program: Program): IAstVisitor {
 
     override fun visit(functionCall: FunctionCall) {
         val otherSub = functionCall.target.targetSubroutine(program.namespace)
-        if(otherSub!=null) {
+        if (otherSub != null) {
             functionCall.definingSubroutine()?.let { thisSub ->
-                subroutinesCalling[thisSub] = subroutinesCalling.getValue(thisSub).plus(otherSub)
-                subroutinesCalledBy[otherSub] = subroutinesCalledBy.getValue(otherSub).plus(functionCall)
+                calls[thisSub] = calls.getValue(thisSub).plus(otherSub)
+                calledBy[otherSub] = calledBy.getValue(otherSub).plus(functionCall)
             }
         }
         super.visit(functionCall)
@@ -148,10 +141,10 @@ class CallGraph(private val program: Program): IAstVisitor {
 
     override fun visit(functionCallStatement: FunctionCallStatement) {
         val otherSub = functionCallStatement.target.targetSubroutine(program.namespace)
-        if(otherSub!=null) {
+        if (otherSub != null) {
             functionCallStatement.definingSubroutine()?.let { thisSub ->
-                subroutinesCalling[thisSub] = subroutinesCalling.getValue(thisSub).plus(otherSub)
-                subroutinesCalledBy[otherSub] = subroutinesCalledBy.getValue(otherSub).plus(functionCallStatement)
+                calls[thisSub] = calls.getValue(thisSub).plus(otherSub)
+                calledBy[otherSub] = calledBy.getValue(otherSub).plus(functionCallStatement)
             }
         }
         super.visit(functionCallStatement)
@@ -159,10 +152,10 @@ class CallGraph(private val program: Program): IAstVisitor {
 
     override fun visit(jump: Jump) {
         val otherSub = jump.identifier?.targetSubroutine(program.namespace)
-        if(otherSub!=null) {
+        if (otherSub != null) {
             jump.definingSubroutine()?.let { thisSub ->
-                subroutinesCalling[thisSub] = subroutinesCalling.getValue(thisSub).plus(otherSub)
-                subroutinesCalledBy[otherSub] = subroutinesCalledBy.getValue(otherSub).plus(jump)
+                calls[thisSub] = calls.getValue(thisSub).plus(otherSub)
+                calledBy[otherSub] = calledBy.getValue(otherSub).plus(jump)
             }
         }
         super.visit(jump)
@@ -175,14 +168,12 @@ class CallGraph(private val program: Program): IAstVisitor {
 
     override fun visit(inlineAssembly: InlineAssembly) {
         // parse inline asm for subroutine calls (jmp, jsr)
-        val scope = inlineAssembly.definingScope()
+        val scope = inlineAssembly.definingSubroutine()
         scanAssemblyCode(inlineAssembly.assembly, inlineAssembly, scope)
         super.visit(inlineAssembly)
     }
 
-    private fun scanAssemblyCode(asm: String, context: Statement, scope: INameScope) {
-        val asmJumpRx = Regex("""[\-+a-zA-Z0-9_ \t]+(jmp|jsr)[ \t]+(\S+).*""", RegexOption.IGNORE_CASE)
-        val asmRefRx = Regex("""[\-+a-zA-Z0-9_ \t]+(...)[ \t]+(\S+).*""", RegexOption.IGNORE_CASE)
+    private fun scanAssemblyCode(asm: String, context: Statement, scope: Subroutine?) {
         asm.lines().forEach { line ->
             val matches = asmJumpRx.matchEntire(line)
             if (matches != null) {
@@ -190,27 +181,30 @@ class CallGraph(private val program: Program): IAstVisitor {
                 if (jumptarget != null && (jumptarget[0].isLetter() || jumptarget[0] == '_')) {
                     val node = program.namespace.lookup(jumptarget.split('.'), context)
                     if (node is Subroutine) {
-                        subroutinesCalling[scope] = subroutinesCalling.getValue(scope).plus(node)
-                        subroutinesCalledBy[node] = subroutinesCalledBy.getValue(node).plus(context)
-                    } else if(jumptarget.contains('.')) {
+                        if(scope!=null)
+                            calls[scope] = calls.getValue(scope).plus(node)
+                        calledBy[node] = calledBy.getValue(node).plus(context)
+                    } else if (jumptarget.contains('.')) {
                         // maybe only the first part already refers to a subroutine
                         val node2 = program.namespace.lookup(listOf(jumptarget.substringBefore('.')), context)
                         if (node2 is Subroutine) {
-                            subroutinesCalling[scope] = subroutinesCalling.getValue(scope).plus(node2)
-                            subroutinesCalledBy[node2] = subroutinesCalledBy.getValue(node2).plus(context)
+                            if(scope!=null)
+                                calls[scope] = calls.getValue(scope).plus(node2)
+                            calledBy[node2] = calledBy.getValue(node2).plus(context)
                         }
                     }
                 }
             } else {
                 val matches2 = asmRefRx.matchEntire(line)
                 if (matches2 != null) {
-                    val target= matches2.groups[2]?.value
+                    val target = matches2.groups[2]?.value
                     if (target != null && (target[0].isLetter() || target[0] == '_')) {
-                        if(target.contains('.')) {
+                        if (target.contains('.')) {
                             val node = program.namespace.lookup(listOf(target.substringBefore('.')), context)
                             if (node is Subroutine) {
-                                subroutinesCalling[scope] = subroutinesCalling.getValue(scope).plus(node)
-                                subroutinesCalledBy[node] = subroutinesCalledBy.getValue(node).plus(context)
+                                if(scope!=null)
+                                    calls[scope] = calls.getValue(scope).plus(node)
+                                calledBy[node] = calledBy.getValue(node).plus(context)
                             }
                         }
                     }
@@ -218,4 +212,55 @@ class CallGraph(private val program: Program): IAstVisitor {
             }
         }
     }
+
+    fun checkRecursiveCalls(errors: ErrorReporter) {
+        val cycles = recursionCycles()
+        if(cycles.any()) {
+            errors.warn("Program contains recursive subroutine calls. These only works in very specific limited scenarios!", Position.DUMMY)
+            val printed = mutableSetOf<Subroutine>()
+            for(chain in cycles) {
+                if(chain[0] !in printed) {
+                    val chainStr = chain.joinToString(" <-- ") { "${it.name} at ${it.position}" }
+                    errors.warn("Cycle in (a subroutine call in) $chainStr", Position.DUMMY)
+                    printed.add(chain[0])
+                }
+            }
+        }
+    }
+
+    private fun recursionCycles(): List<List<Subroutine>> {
+        val chains = mutableListOf<MutableList<Subroutine>>()
+        for(caller in calls.keys) {
+            val visited = calls.keys.associateWith { false }.toMutableMap()
+            val recStack = calls.keys.associateWith { false }.toMutableMap()
+            val chain = mutableListOf<Subroutine>()
+            if(hasCycle(caller, visited, recStack, chain))
+                chains.add(chain)
+        }
+        return chains
+    }
+
+    private fun hasCycle(sub: Subroutine, visited: MutableMap<Subroutine, Boolean>, recStack: MutableMap<Subroutine, Boolean>, chain: MutableList<Subroutine>): Boolean {
+        // mark current node as visited and add to recursion stack
+        if(recStack[sub]==true)
+            return true
+        if(visited[sub]==true)
+            return false
+
+        // mark visited and add to recursion stack
+        visited[sub] = true
+        recStack[sub] = true
+
+        // recurse for all neighbours
+        for(called in calls.getValue(sub)) {
+            if(hasCycle(called, visited, recStack, chain)) {
+                chain.add(called)
+                return true
+            }
+        }
+
+        // pop from recursion stack
+        recStack[sub] = false
+        return false
+    }
 }

compiler/src/prog8/optimizer/ConstExprEvaluator.kt

@@ -132,11 +132,11 @@ class ConstExprEvaluator {
     private fun bitwiseand(left: NumericLiteralValue, right: NumericLiteralValue): NumericLiteralValue {
         if(left.type== DataType.UBYTE) {
             if(right.type in IntegerDatatypes) {
-                return NumericLiteralValue(DataType.UBYTE, (left.number.toInt() or (right.number.toInt() and 255)).toShort(), left.position)
+                return NumericLiteralValue(DataType.UBYTE, (left.number.toInt() and (right.number.toInt() and 255)).toShort(), left.position)
             }
         } else if(left.type== DataType.UWORD) {
             if(right.type in IntegerDatatypes) {
-                return NumericLiteralValue(DataType.UWORD, left.number.toInt() or right.number.toInt(), left.position)
+                return NumericLiteralValue(DataType.UWORD, left.number.toInt() and right.number.toInt(), left.position)
             }
         }
         throw ExpressionError("cannot calculate $left & $right", left.position)
@@ -163,7 +163,7 @@ class ConstExprEvaluator {
         val error = "cannot add $left and $right"
         return when (left.type) {
             in IntegerDatatypes -> when (right.type) {
-                in IntegerDatatypes -> NumericLiteralValue.optimalNumeric(left.number.toInt() + right.number.toInt(), left.position)
+                in IntegerDatatypes -> NumericLiteralValue.optimalInteger(left.number.toInt() + right.number.toInt(), left.position)
                 DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toInt() + right.number.toDouble(), left.position)
                 else -> throw ExpressionError(error, left.position)
             }
@@ -180,7 +180,7 @@ class ConstExprEvaluator {
         val error = "cannot subtract $left and $right"
         return when (left.type) {
             in IntegerDatatypes -> when (right.type) {
-                in IntegerDatatypes -> NumericLiteralValue.optimalNumeric(left.number.toInt() - right.number.toInt(), left.position)
+                in IntegerDatatypes -> NumericLiteralValue.optimalInteger(left.number.toInt() - right.number.toInt(), left.position)
                 DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toInt() - right.number.toDouble(), left.position)
                 else -> throw ExpressionError(error, left.position)
             }
@@ -197,7 +197,7 @@ class ConstExprEvaluator {
         val error = "cannot multiply ${left.type} and ${right.type}"
         return when (left.type) {
             in IntegerDatatypes -> when (right.type) {
-                in IntegerDatatypes -> NumericLiteralValue.optimalNumeric(left.number.toInt() * right.number.toInt(), left.position)
+                in IntegerDatatypes -> NumericLiteralValue.optimalInteger(left.number.toInt() * right.number.toInt(), left.position)
                 DataType.FLOAT -> NumericLiteralValue(DataType.FLOAT, left.number.toInt() * right.number.toDouble(), left.position)
                 else -> throw ExpressionError(error, left.position)
             }
@@ -220,7 +220,7 @@ class ConstExprEvaluator {
                 in IntegerDatatypes -> {
                     if(right.number.toInt()==0) divideByZeroError(right.position)
                     val result: Int = left.number.toInt() / right.number.toInt()
-                    NumericLiteralValue.optimalNumeric(result, left.position)
+                    NumericLiteralValue.optimalInteger(result, left.position)
                 }
                 DataType.FLOAT -> {
                     if(right.number.toDouble()==0.0) divideByZeroError(right.position)

compiler/src/prog8/optimizer/ConstantFolding.kt

@@ -1,712 +0,0 @@
-package prog8.optimizer
-
-import prog8.ast.IFunctionCall
-import prog8.ast.Program
-import prog8.ast.base.*
-import prog8.ast.expressions.*
-import prog8.ast.processing.IAstModifyingVisitor
-import prog8.ast.processing.fixupArrayEltDatatypesFromVardecl
-import prog8.ast.processing.fixupArrayEltDatatypes
-import prog8.ast.statements.*
-import prog8.compiler.target.CompilationTarget
-import prog8.functions.BuiltinFunctions
-import kotlin.math.floor
-
-
-class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
-    var optimizationsDone: Int = 0
-    var errors : MutableList<AstException> = mutableListOf()
-    private val reportedErrorMessages = mutableSetOf<String>()
-
-    fun addError(x: AstException) {
-        // check that we don't add the isSameAs error more than once
-        if(x.toString() !in reportedErrorMessages) {
-            reportedErrorMessages.add(x.toString())
-            errors.add(x)
-        }
-    }
-
-    override fun visit(decl: VarDecl): Statement {
-        // the initializer value can't refer to the variable itself (recursive definition)
-        // TODO: use call tree for this?
-        if(decl.value?.referencesIdentifiers(decl.name) == true || decl.arraysize?.index?.referencesIdentifiers(decl.name) == true) {
-            errors.add(ExpressionError("recursive var declaration", decl.position))
-            return decl
-        }
-
-        if(decl.type==VarDeclType.CONST || decl.type==VarDeclType.VAR) {
-            if(decl.isArray){
-                if(decl.arraysize==null) {
-                    // for arrays that have no size specifier (or a non-constant one) attempt to deduce the size
-                    val arrayval = decl.value as? ArrayLiteralValue
-                    if(arrayval!=null) {
-                        decl.arraysize = ArrayIndex(NumericLiteralValue.optimalInteger(arrayval.value.size, decl.position), decl.position)
-                        optimizationsDone++
-                    }
-                }
-                else if(decl.arraysize?.size()==null) {
-                    val size = decl.arraysize!!.index.accept(this)
-                    if(size is NumericLiteralValue) {
-                        decl.arraysize = ArrayIndex(size, decl.position)
-                        optimizationsDone++
-                    }
-                }
-            }
-
-            when(decl.datatype) {
-                DataType.FLOAT -> {
-                    // vardecl: for scalar float vars, promote constant integer initialization values to floats
-                    val litval = decl.value as? NumericLiteralValue
-                    if (litval!=null && litval.type in IntegerDatatypes) {
-                        val newValue = NumericLiteralValue(DataType.FLOAT, litval.number.toDouble(), litval.position)
-                        decl.value = newValue
-                        optimizationsDone++
-                        return super.visit(decl)
-                    }
-                }
-                DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W -> {
-                    val numericLv = decl.value as? NumericLiteralValue
-                    val rangeExpr = decl.value as? RangeExpr
-                    if(rangeExpr!=null) {
-                        // convert the initializer range expression to an actual array
-                        val declArraySize = decl.arraysize?.size()
-                        if(declArraySize!=null && declArraySize!=rangeExpr.size())
-                            errors.add(ExpressionError("range expression size doesn't match declared array size", decl.value?.position!!))
-                        val constRange = rangeExpr.toConstantIntegerRange()
-                        if(constRange!=null) {
-                            val eltType = rangeExpr.inferType(program).typeOrElse(DataType.UBYTE)
-                            if(eltType in ByteDatatypes) {
-                                decl.value = ArrayLiteralValue(decl.datatype,
-                                        constRange.map { NumericLiteralValue(eltType, it.toShort(), decl.value!!.position) }.toTypedArray(),
-                                        position = decl.value!!.position)
-                            } else {
-                                decl.value = ArrayLiteralValue(decl.datatype,
-                                        constRange.map { NumericLiteralValue(eltType, it, decl.value!!.position) }.toTypedArray(),
-                                        position = decl.value!!.position)
-                            }
-                            decl.value!!.linkParents(decl)
-                            optimizationsDone++
-                            return super.visit(decl)
-                        }
-                    }
-                    if(numericLv!=null && numericLv.type== DataType.FLOAT)
-                        errors.add(ExpressionError("arraysize requires only integers here", numericLv.position))
-                    val size = decl.arraysize?.size() ?: return decl
-                    if (rangeExpr==null && numericLv!=null) {
-                        // arraysize initializer is empty or a single int, and we know the size; create the arraysize.
-                        val fillvalue = numericLv.number.toInt()
-                        when(decl.datatype){
-                            DataType.ARRAY_UB -> {
-                                if(fillvalue !in 0..255)
-                                    errors.add(ExpressionError("ubyte value overflow", numericLv.position))
-                            }
-                            DataType.ARRAY_B -> {
-                                if(fillvalue !in -128..127)
-                                    errors.add(ExpressionError("byte value overflow", numericLv.position))
-                            }
-                            DataType.ARRAY_UW -> {
-                                if(fillvalue !in 0..65535)
-                                    errors.add(ExpressionError("uword value overflow", numericLv.position))
-                            }
-                            DataType.ARRAY_W -> {
-                                if(fillvalue !in -32768..32767)
-                                    errors.add(ExpressionError("word value overflow", numericLv.position))
-                            }
-                            else -> {}
-                        }
-                        // create the array itself, filled with the fillvalue.
-                        val array = Array(size) {fillvalue}.map { NumericLiteralValue.optimalInteger(it, numericLv.position) as Expression}.toTypedArray()
-                        val refValue = ArrayLiteralValue(decl.datatype, array, position = numericLv.position)
-                        decl.value = refValue
-                        refValue.parent=decl
-                        optimizationsDone++
-                        return super.visit(decl)
-                    }
-                }
-                DataType.ARRAY_F  -> {
-                    val size = decl.arraysize?.size() ?: return decl
-                    val litval = decl.value as? NumericLiteralValue
-                    if(litval==null) {
-                        // there's no initialization value, but the size is known, so we're ok.
-                        return super.visit(decl)
-                    } else {
-                        // arraysize initializer is a single int, and we know the size.
-                        val fillvalue = litval.number.toDouble()
-                        if (fillvalue < CompilationTarget.machine.FLOAT_MAX_NEGATIVE || fillvalue > CompilationTarget.machine.FLOAT_MAX_POSITIVE)
-                            errors.add(ExpressionError("float value overflow", litval.position))
-                        else {
-                            // create the array itself, filled with the fillvalue.
-                            val array = Array(size) {fillvalue}.map { NumericLiteralValue(DataType.FLOAT, it, litval.position) as Expression}.toTypedArray()
-                            val refValue = ArrayLiteralValue(DataType.ARRAY_F, array, position = litval.position)
-                            decl.value = refValue
-                            refValue.parent=decl
-                            optimizationsDone++
-                            return super.visit(decl)
-                        }
-                    }
-                }
-                else -> {
-                    // nothing to do for this type
-                    // this includes strings and structs
-                }
-            }
-        }
-
-        return super.visit(decl)
-    }
-
-    /**
-     * replace identifiers that refer to const value, with the value itself (if it's a simple type)
-     */
-    override fun visit(identifier: IdentifierReference): Expression {
-        // don't replace when it's an assignment target or loop variable
-        if(identifier.parent is AssignTarget)
-            return identifier
-        var forloop = identifier.parent as? ForLoop
-        if(forloop==null)
-            forloop = identifier.parent.parent as? ForLoop
-        if(forloop!=null && identifier===forloop.loopVar)
-            return identifier
-
-        return try {
-            val cval = identifier.constValue(program) ?: return identifier
-            return when (cval.type) {
-                in NumericDatatypes -> {
-                    val copy = NumericLiteralValue(cval.type, cval.number, identifier.position)
-                    copy.parent = identifier.parent
-                    copy
-                }
-                in PassByReferenceDatatypes -> throw FatalAstException("pass-by-reference type should not be considered a constant")
-                else -> identifier
-            }
-        } catch (ax: AstException) {
-            addError(ax)
-            identifier
-        }
-    }
-
-    override fun visit(functionCall: FunctionCall): Expression {
-        super.visit(functionCall)
-        typeCastConstArguments(functionCall)
-        return try {
-            functionCall.constValue(program) ?: functionCall
-        } catch (ax: AstException) {
-            addError(ax)
-            functionCall
-        }
-    }
-
-    override fun visit(functionCallStatement: FunctionCallStatement): Statement {
-        super.visit(functionCallStatement)
-        typeCastConstArguments(functionCallStatement)
-        return functionCallStatement
-    }
-
-    private fun typeCastConstArguments(functionCall: IFunctionCall) {
-        if(functionCall.target.nameInSource.size==1) {
-            val builtinFunction = BuiltinFunctions[functionCall.target.nameInSource.single()]
-            if(builtinFunction!=null) {
-                // match the arguments of a builtin function signature.
-                for(arg in functionCall.args.withIndex().zip(builtinFunction.parameters)) {
-                    val possibleDts = arg.second.possibleDatatypes
-                    val argConst = arg.first.value.constValue(program)
-                    if(argConst!=null && argConst.type !in possibleDts) {
-                        val convertedValue = argConst.cast(possibleDts.first())
-                        functionCall.args[arg.first.index] = convertedValue
-                        optimizationsDone++
-                    }
-                }
-                return
-            }
-        }
-        // match the arguments of a subroutine.
-        val subroutine = functionCall.target.targetSubroutine(program.namespace)
-        if(subroutine!=null) {
-            // if types differ, try to typecast constant arguments to the function call to the desired data type of the parameter
-            for(arg in functionCall.args.withIndex().zip(subroutine.parameters)) {
-                val expectedDt = arg.second.type
-                val argConst = arg.first.value.constValue(program)
-                if(argConst!=null && argConst.type!=expectedDt) {
-                    val convertedValue = argConst.cast(expectedDt)
-                    functionCall.args[arg.first.index] = convertedValue
-                    optimizationsDone++
-                }
-            }
-        }
-    }
-
-    override fun visit(memread: DirectMemoryRead): Expression {
-        // @( &thing )  -->  thing
-        val addrOf = memread.addressExpression as? AddressOf
-        if(addrOf!=null)
-            return super.visit(addrOf.identifier)
-        return super.visit(memread)
-    }
-
-    /**
-     * Try to accept a unary prefix expression.
-     * 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
-     */
-    override fun visit(expr: PrefixExpression): Expression {
-        return try {
-            val prefixExpr=super.visit(expr)
-            if(prefixExpr !is PrefixExpression)
-                return prefixExpr
-
-            val subexpr = prefixExpr.expression
-            if (subexpr is NumericLiteralValue) {
-                // accept prefixed literal values (such as -3, not true)
-                return when (prefixExpr.operator) {
-                    "+" -> subexpr
-                    "-" -> when (subexpr.type) {
-                        in IntegerDatatypes -> {
-                            optimizationsDone++
-                            NumericLiteralValue.optimalNumeric(-subexpr.number.toInt(), subexpr.position)
-                        }
-                        DataType.FLOAT -> {
-                            optimizationsDone++
-                            NumericLiteralValue(DataType.FLOAT, -subexpr.number.toDouble(), subexpr.position)
-                        }
-                        else -> throw ExpressionError("can only take negative of int or float", subexpr.position)
-                    }
-                    "~" -> when (subexpr.type) {
-                        in IntegerDatatypes -> {
-                            optimizationsDone++
-                            NumericLiteralValue.optimalNumeric(subexpr.number.toInt().inv(), subexpr.position)
-                        }
-                        else -> throw ExpressionError("can only take bitwise inversion of int", subexpr.position)
-                    }
-                    "not" -> {
-                        optimizationsDone++
-                        NumericLiteralValue.fromBoolean(subexpr.number.toDouble() == 0.0, subexpr.position)
-                    }
-                    else -> throw ExpressionError(prefixExpr.operator, subexpr.position)
-                }
-            }
-            return prefixExpr
-        } catch (ax: AstException) {
-            addError(ax)
-            expr
-        }
-    }
-
-    /**
-     * Try to accept a binary expression.
-     * Compile-time constant sub expressions will be evaluated on the spot.
-     * For instance, "9 * (4 + 2)" will be optimized into the integer literal 54.
-     *
-     * More complex stuff: reordering to group constants:
-     * If one of our operands is a Constant,
-     *   and the other operand is a Binary expression,
-     *   and one of ITS operands is a Constant,
-     *   and ITS other operand is NOT a Constant,
-     *   ...it may be possible to rewrite the expression to group the two Constants together,
-     *      to allow them to be const-folded away.
-     *
-     *  examples include:
-     *        (X / c1) * c2  ->  X / (c2/c1)
-     *        (X + c1) - c2  ->  X + (c1-c2)
-     */
-    override fun visit(expr: BinaryExpression): Expression {
-        return try {
-            super.visit(expr)
-
-            if(expr.left is StringLiteralValue || expr.left is ArrayLiteralValue
-                    || expr.right is StringLiteralValue || expr.right is ArrayLiteralValue)
-                throw FatalAstException("binexpr with reference litval instead of numeric")
-
-            val leftconst = expr.left.constValue(program)
-            val rightconst = expr.right.constValue(program)
-
-            val subExpr: BinaryExpression? = when {
-                leftconst!=null -> expr.right as? BinaryExpression
-                rightconst!=null -> expr.left as? BinaryExpression
-                else -> null
-            }
-            if(subExpr!=null) {
-                val subleftconst = subExpr.left.constValue(program)
-                val subrightconst = subExpr.right.constValue(program)
-                if ((subleftconst != null && subrightconst == null) || (subleftconst==null && subrightconst!=null)) {
-                    // try reordering.
-                    return groupTwoConstsTogether(expr, subExpr,
-                            leftconst != null, rightconst != null,
-                            subleftconst != null, subrightconst != null)
-                }
-            }
-
-            // const fold when both operands are a const
-            return when {
-                leftconst != null && rightconst != null -> {
-                    optimizationsDone++
-                    val evaluator = ConstExprEvaluator()
-                    evaluator.evaluate(leftconst, expr.operator, rightconst)
-                }
-
-                else -> expr
-            }
-        } catch (ax: AstException) {
-            addError(ax)
-            expr
-        }
-    }
-
-    private fun groupTwoConstsTogether(expr: BinaryExpression,
-                                       subExpr: BinaryExpression,
-                                       leftIsConst: Boolean,
-                                       rightIsConst: Boolean,
-                                       subleftIsConst: Boolean,
-                                       subrightIsConst: Boolean): Expression
-    {
-        // todo: this implements only a small set of possible reorderings at this time
-        if(expr.operator==subExpr.operator) {
-            // both operators are the isSameAs.
-            // If + or *,  we can simply swap the const of expr and Var in subexpr.
-            if(expr.operator=="+" || expr.operator=="*") {
-                if(leftIsConst) {
-                    if(subleftIsConst)
-                        expr.left = subExpr.right.also { subExpr.right = expr.left }
-                    else
-                        expr.left = subExpr.left.also { subExpr.left = expr.left }
-                } else {
-                    if(subleftIsConst)
-                        expr.right = subExpr.right.also {subExpr.right = expr.right }
-                    else
-                        expr.right = subExpr.left.also { subExpr.left = expr.right }
-                }
-                optimizationsDone++
-                return expr
-            }
-
-            // If - or /,  we simetimes must reorder more, and flip operators (- -> +, / -> *)
-            if(expr.operator=="-" || expr.operator=="/") {
-                optimizationsDone++
-                if(leftIsConst) {
-                    return if(subleftIsConst) {
-                        val tmp = subExpr.right
-                        subExpr.right = subExpr.left
-                        subExpr.left = expr.left
-                        expr.left = tmp
-                        expr.operator = if(expr.operator=="-") "+" else "*"
-                        expr
-                    } else
-                        BinaryExpression(
-                                BinaryExpression(expr.left, if (expr.operator == "-") "+" else "*", subExpr.right, subExpr.position),
-                                expr.operator, subExpr.left, expr.position)
-                } else {
-                    return if(subleftIsConst) {
-                        expr.right = subExpr.right.also { subExpr.right = expr.right }
-                        expr
-                    } else
-                        BinaryExpression(
-                                subExpr.left, expr.operator,
-                                BinaryExpression(expr.right, if (expr.operator == "-") "+" else "*", subExpr.right, subExpr.position),
-                                expr.position)
-                }
-            }
-            return expr
-
-        }
-        else
-        {
-
-            if(expr.operator=="/" && subExpr.operator=="*") {
-                optimizationsDone++
-                if(leftIsConst) {
-                    return if(subleftIsConst) {
-                        // C1/(C2*V) -> (C1/C2)/V
-                        BinaryExpression(
-                                BinaryExpression(expr.left, "/", subExpr.left, subExpr.position),
-                                "/",
-                                subExpr.right, expr.position)
-                    } else {
-                        // C1/(V*C2) -> (C1/C2)/V
-                        BinaryExpression(
-                                BinaryExpression(expr.left, "/", subExpr.right, subExpr.position),
-                                "/",
-                                subExpr.left, expr.position)
-                    }
-                } else {
-                    return if(subleftIsConst) {
-                        // (C1*V)/C2 -> (C1/C2)*V
-                        BinaryExpression(
-                                BinaryExpression(subExpr.left, "/", expr.right, subExpr.position),
-                                "*",
-                                subExpr.right, expr.position)
-                    } else {
-                        // (V*C1)/C2 -> (C1/C2)*V
-                        BinaryExpression(
-                                BinaryExpression(subExpr.right, "/", expr.right, subExpr.position),
-                                "*",
-                                subExpr.left, expr.position)
-                    }
-                }
-            }
-            else if(expr.operator=="*" && subExpr.operator=="/") {
-                optimizationsDone++
-                if(leftIsConst) {
-                    return if(subleftIsConst) {
-                        // C1*(C2/V) -> (C1*C2)/V
-                        BinaryExpression(
-                                BinaryExpression(expr.left, "*", subExpr.left, subExpr.position),
-                                "/",
-                                subExpr.right, expr.position)
-                    } else {
-                        // C1*(V/C2) -> (C1/C2)*V
-                        BinaryExpression(
-                                BinaryExpression(expr.left, "/", subExpr.right, subExpr.position),
-                                "*",
-                                subExpr.left, expr.position)
-                    }
-                } else {
-                    return if(subleftIsConst) {
-                        // (C1/V)*C2 -> (C1*C2)/V
-                        BinaryExpression(
-                                BinaryExpression(subExpr.left, "*", expr.right, subExpr.position),
-                                "/",
-                                subExpr.right, expr.position)
-                    } else {
-                        // (V/C1)*C2 -> (C1/C2)*V
-                        BinaryExpression(
-                                BinaryExpression(expr.right, "/", subExpr.right, subExpr.position),
-                                "*",
-                                subExpr.left, expr.position)
-                    }
-                }
-            }
-            else if(expr.operator=="+" && subExpr.operator=="-") {
-                optimizationsDone++
-                if(leftIsConst){
-                    return if(subleftIsConst){
-                        // c1+(c2-v)  ->  (c1+c2)-v
-                        BinaryExpression(
-                                BinaryExpression(expr.left, "+", subExpr.left, subExpr.position),
-                                "-",
-                                subExpr.right, expr.position)
-                    } else {
-                        // c1+(v-c2)  ->  v+(c1-c2)
-                        BinaryExpression(
-                                BinaryExpression(expr.left, "-", subExpr.right, subExpr.position),
-                                "+",
-                                subExpr.left, expr.position)
-                    }
-                } else {
-                    return if(subleftIsConst) {
-                        // (c1-v)+c2  ->  (c1+c2)-v
-                        BinaryExpression(
-                                BinaryExpression(subExpr.left, "+", expr.right, subExpr.position),
-                                "-",
-                                subExpr.right, expr.position)
-                    } else {
-                        // (v-c1)+c2  ->  v+(c2-c1)
-                        BinaryExpression(
-                                BinaryExpression(expr.right, "-", subExpr.right, subExpr.position),
-                                "+",
-                                subExpr.left, expr.position)
-                    }
-                }
-            }
-            else if(expr.operator=="-" && subExpr.operator=="+") {
-                optimizationsDone++
-                if(leftIsConst) {
-                    return if(subleftIsConst) {
-                        // c1-(c2+v)  ->  (c1-c2)-v
-                        BinaryExpression(
-                                BinaryExpression(expr.left, "-", subExpr.left, subExpr.position),
-                                "-",
-                                subExpr.right, expr.position)
-                    } else {
-                        // c1-(v+c2)  ->  (c1-c2)-v
-                        BinaryExpression(
-                                BinaryExpression(expr.left, "-", subExpr.right, subExpr.position),
-                                "-",
-                                subExpr.left, expr.position)
-                    }
-                } else {
-                    return if(subleftIsConst) {
-                        // (c1+v)-c2  ->  v+(c1-c2)
-                        BinaryExpression(
-                                BinaryExpression(subExpr.left, "-", expr.right, subExpr.position),
-                                "+",
-                                subExpr.right, expr.position)
-                    } else {
-                        // (v+c1)-c2  ->  v+(c1-c2)
-                        BinaryExpression(
-                                BinaryExpression(subExpr.right, "-", expr.right, subExpr.position),
-                                "+",
-                                subExpr.left, expr.position)
-                    }
-                }
-            }
-
-            return expr
-        }
-    }
-
-    override fun visit(forLoop: ForLoop): Statement {
-
-        fun adjustRangeDt(rangeFrom: NumericLiteralValue, targetDt: DataType, rangeTo: NumericLiteralValue, stepLiteral: NumericLiteralValue?, range: RangeExpr): RangeExpr {
-            val newFrom: NumericLiteralValue
-            val newTo: NumericLiteralValue
-            try {
-                newFrom = rangeFrom.cast(targetDt)
-                newTo = rangeTo.cast(targetDt)
-            } catch (x: ExpressionError) {
-                return range
-            }
-            val newStep: Expression = try {
-                stepLiteral?.cast(targetDt)?: range.step
-            } catch(ee: ExpressionError) {
-                range.step
-            }
-            return RangeExpr(newFrom, newTo, newStep, range.position)
-        }
-
-        val forLoop2 = super.visit(forLoop) as ForLoop
-
-        // check if we need to adjust an array literal to the loop variable's datatype
-        val array = forLoop2.iterable as? ArrayLiteralValue
-        if(array!=null) {
-            val loopvarDt: DataType = when {
-                forLoop.loopVar!=null -> forLoop.loopVar!!.inferType(program).typeOrElse(DataType.UBYTE)
-                forLoop.loopRegister!=null -> DataType.UBYTE
-                else -> throw FatalAstException("weird for loop")
-            }
-
-            val arrayType = when(loopvarDt) {
-                DataType.UBYTE -> DataType.ARRAY_UB
-                DataType.BYTE -> DataType.ARRAY_B
-                DataType.UWORD -> DataType.ARRAY_UW
-                DataType.WORD -> DataType.ARRAY_W
-                DataType.FLOAT -> DataType.ARRAY_F
-                else -> throw FatalAstException("invalid array elt type")
-            }
-            val array2 = array.cast(arrayType)
-            if(array2!=null && array2!==array) {
-                forLoop2.iterable = array2
-                array2.linkParents(forLoop2)
-            }
-        }
-
-        // adjust the datatype of a range expression in for loops to the loop variable.
-        val iterableRange = forLoop2.iterable as? RangeExpr ?: return forLoop2
-        val rangeFrom = iterableRange.from as? NumericLiteralValue
-        val rangeTo = iterableRange.to as? NumericLiteralValue
-        if(rangeFrom==null || rangeTo==null) return forLoop2
-
-        val loopvar = forLoop2.loopVar?.targetVarDecl(program.namespace)
-        if(loopvar!=null) {
-            val stepLiteral = iterableRange.step as? NumericLiteralValue
-            when(loopvar.datatype) {
-                DataType.UBYTE -> {
-                    if(rangeFrom.type!= DataType.UBYTE) {
-                        // attempt to translate the iterable into ubyte values
-                        forLoop2.iterable = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
-                    }
-                }
-                DataType.BYTE -> {
-                    if(rangeFrom.type!= DataType.BYTE) {
-                        // attempt to translate the iterable into byte values
-                        forLoop2.iterable = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
-                    }
-                }
-                DataType.UWORD -> {
-                    if(rangeFrom.type!= DataType.UWORD) {
-                        // attempt to translate the iterable into uword values
-                        forLoop2.iterable = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
-                    }
-                }
-                DataType.WORD -> {
-                    if(rangeFrom.type!= DataType.WORD) {
-                        // attempt to translate the iterable into word values
-                        forLoop2.iterable = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
-                    }
-                }
-                else -> throw FatalAstException("invalid loopvar datatype $loopvar")
-            }
-        }
-        return forLoop2
-    }
-
-    override fun visit(arrayLiteral: ArrayLiteralValue): Expression {
-        val array = super.visit(arrayLiteral)
-        if(array is ArrayLiteralValue) {
-            val vardecl = array.parent as? VarDecl
-            return if (vardecl!=null) {
-                fixupArrayEltDatatypesFromVardecl(array, vardecl)
-            } else {
-                // it's not an array associated with a vardecl, attempt to guess the data type from the array values
-                fixupArrayEltDatatypes(array, program)
-            }
-        }
-        return array
-    }
-
-    override fun visit(assignment: Assignment): Statement {
-        super.visit(assignment)
-        val lv = assignment.value as? NumericLiteralValue
-        if(lv!=null) {
-            // see if we can promote/convert a literal value to the required datatype
-            val idt = assignment.target.inferType(program, assignment)
-            if(!idt.isKnown)
-                return assignment
-            when(idt.typeOrElse(DataType.STRUCT)) {
-                DataType.UWORD -> {
-                    // we can convert to UWORD: any UBYTE, BYTE/WORD that are >=0, FLOAT that's an integer 0..65535,
-                    if(lv.type== DataType.UBYTE)
-                        assignment.value = NumericLiteralValue(DataType.UWORD, lv.number.toInt(), lv.position)
-                    else if(lv.type== DataType.BYTE && lv.number.toInt()>=0)
-                        assignment.value = NumericLiteralValue(DataType.UWORD, lv.number.toInt(), lv.position)
-                    else if(lv.type== DataType.WORD && lv.number.toInt()>=0)
-                        assignment.value = NumericLiteralValue(DataType.UWORD, lv.number.toInt(), lv.position)
-                    else if(lv.type== DataType.FLOAT) {
-                        val d = lv.number.toDouble()
-                        if(floor(d)==d && d>=0 && d<=65535)
-                            assignment.value = NumericLiteralValue(DataType.UWORD, floor(d).toInt(), lv.position)
-                    }
-                }
-                DataType.UBYTE -> {
-                    // we can convert to UBYTE: UWORD <=255, BYTE >=0, FLOAT that's an integer 0..255,
-                    if(lv.type== DataType.UWORD && lv.number.toInt() <= 255)
-                        assignment.value = NumericLiteralValue(DataType.UBYTE, lv.number.toShort(), lv.position)
-                    else if(lv.type== DataType.BYTE && lv.number.toInt() >=0)
-                        assignment.value = NumericLiteralValue(DataType.UBYTE, lv.number.toShort(), lv.position)
-                    else if(lv.type== DataType.FLOAT) {
-                        val d = lv.number.toDouble()
-                        if(floor(d)==d && d >=0 && d<=255)
-                            assignment.value = NumericLiteralValue(DataType.UBYTE, floor(d).toShort(), lv.position)
-                    }
-                }
-                DataType.BYTE -> {
-                    // we can convert to BYTE: UWORD/UBYTE <= 127, FLOAT that's an integer 0..127
-                    if(lv.type== DataType.UWORD && lv.number.toInt() <= 127)
-                        assignment.value = NumericLiteralValue(DataType.BYTE, lv.number.toShort(), lv.position)
-                    else if(lv.type== DataType.UBYTE && lv.number.toInt() <= 127)
-                        assignment.value = NumericLiteralValue(DataType.BYTE, lv.number.toShort(), lv.position)
-                    else if(lv.type== DataType.FLOAT) {
-                        val d = lv.number.toDouble()
-                        if(floor(d)==d && d>=0 && d<=127)
-                            assignment.value = NumericLiteralValue(DataType.BYTE, floor(d).toShort(), lv.position)
-                    }
-                }
-                DataType.WORD -> {
-                    // we can convert to WORD: any UBYTE/BYTE, UWORD <= 32767, FLOAT that's an integer -32768..32767,
-                    if(lv.type== DataType.UBYTE || lv.type== DataType.BYTE)
-                        assignment.value = NumericLiteralValue(DataType.WORD, lv.number.toInt(), lv.position)
-                    else if(lv.type== DataType.UWORD && lv.number.toInt() <= 32767)
-                        assignment.value = NumericLiteralValue(DataType.WORD, lv.number.toInt(), lv.position)
-                    else if(lv.type== DataType.FLOAT) {
-                        val d = lv.number.toDouble()
-                        if(floor(d)==d && d>=-32768 && d<=32767)
-                            assignment.value = NumericLiteralValue(DataType.BYTE, floor(d).toShort(), lv.position)
-                    }
-                }
-                DataType.FLOAT -> {
-                    assignment.value = NumericLiteralValue(DataType.FLOAT, lv.number.toDouble(), lv.position)
-                }
-                else -> {}
-            }
-        }
-        return assignment
-    }
-}

compiler/src/prog8/optimizer/ConstantFoldingOptimizer.kt

@@ -0,0 +1,455 @@
+package prog8.optimizer
+
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.processing.AstWalker
+import prog8.ast.processing.IAstModification
+import prog8.ast.statements.*
+
+
+internal class ConstantFoldingOptimizer(private val program: Program) : AstWalker() {
+    private val noModifications = emptyList<IAstModification>()
+
+    override fun before(memread: DirectMemoryRead, parent: Node): Iterable<IAstModification> {
+        // @( &thing )  -->  thing
+        val addrOf = memread.addressExpression as? AddressOf
+        return if(addrOf!=null)
+            listOf(IAstModification.ReplaceNode(memread, addrOf.identifier, parent))
+        else
+            noModifications
+    }
+
+    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 NumericLiteralValue) {
+            // 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,
+                                NumericLiteralValue.optimalInteger(-subexpr.number.toInt(), subexpr.position),
+                                parent))
+                    }
+                    DataType.FLOAT -> {
+                        listOf(IAstModification.ReplaceNode(expr,
+                                NumericLiteralValue(DataType.FLOAT, -subexpr.number.toDouble(), 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,
+                                NumericLiteralValue(DataType.BYTE, subexpr.number.toInt().inv(), subexpr.position),
+                                parent))
+                    }
+                    DataType.UBYTE -> {
+                        listOf(IAstModification.ReplaceNode(expr,
+                                NumericLiteralValue(DataType.UBYTE, subexpr.number.toInt().inv() and 255, subexpr.position),
+                                parent))
+                    }
+                    DataType.WORD -> {
+                        listOf(IAstModification.ReplaceNode(expr,
+                                NumericLiteralValue(DataType.WORD, subexpr.number.toInt().inv(), subexpr.position),
+                                parent))
+                    }
+                    DataType.UWORD -> {
+                        listOf(IAstModification.ReplaceNode(expr,
+                                NumericLiteralValue(DataType.UWORD, subexpr.number.toInt().inv() and 65535, subexpr.position),
+                                parent))
+                    }
+                    else -> throw ExpressionError("can only take bitwise inversion of int", subexpr.position)
+                }
+                "not" -> {
+                    listOf(IAstModification.ReplaceNode(expr,
+                            NumericLiteralValue.fromBoolean(subexpr.number.toDouble() == 0.0, subexpr.position),
+                            parent))
+                }
+                else -> throw ExpressionError(expr.operator, subexpr.position)
+            }
+        }
+        return noModifications
+    }
+
+    /**
+     * Try to constfold a binary expression.
+     * Compile-time constant sub expressions will be evaluated on the spot.
+     * For instance, "9 * (4 + 2)" will be optimized into the integer literal 54.
+     *
+     * More complex stuff: reordering to group constants:
+     * If one of our operands is a Constant,
+     *   and the other operand is a Binary expression,
+     *   and one of ITS operands is a Constant,
+     *   and ITS other operand is NOT a Constant,
+     *   ...it may be possible to rewrite the expression to group the two Constants together,
+     *      to allow them to be const-folded away.
+     *
+     *  examples include:
+     *        (X / c1) * c2  ->  X / (c2/c1)
+     *        (X + c1) - c2  ->  X + (c1-c2)
+     */
+    override fun after(expr: BinaryExpression, parent: Node): Iterable<IAstModification> {
+        val leftconst = expr.left.constValue(program)
+        val rightconst = expr.right.constValue(program)
+
+        val subExpr: BinaryExpression? = when {
+            leftconst!=null -> expr.right as? BinaryExpression
+            rightconst!=null -> expr.left as? BinaryExpression
+            else -> null
+        }
+        if(subExpr!=null) {
+            val subleftconst = subExpr.left.constValue(program)
+            val subrightconst = subExpr.right.constValue(program)
+            if ((subleftconst != null && subrightconst == null) || (subleftconst==null && subrightconst!=null)) {
+                // try reordering.
+                val change = groupTwoConstsTogether(expr, subExpr,
+                        leftconst != null, rightconst != null,
+                        subleftconst != null, subrightconst != null)
+                return change?.let { listOf(it) } ?: noModifications
+            }
+        }
+
+        // const fold when both operands are a const
+        if(leftconst != null && rightconst != null) {
+            val evaluator = ConstExprEvaluator()
+            val result = evaluator.evaluate(leftconst, expr.operator, rightconst)
+            return listOf(IAstModification.ReplaceNode(expr, result, parent))
+        }
+
+        return noModifications
+    }
+
+    override fun after(array: ArrayLiteralValue, parent: Node): Iterable<IAstModification> {
+        // because constant folding can result in arrays that are now suddenly capable
+        // of telling the type of all their elements (for instance, when they contained -2 which
+        // was a prefix expression earlier), we recalculate the array's datatype.
+        if(array.type.isKnown)
+            return noModifications
+
+        // if the array literalvalue is inside an array vardecl, take the type from that
+        // otherwise infer it from the elements of the array
+        val vardeclType = (array.parent as? VarDecl)?.datatype
+        if(vardeclType!=null) {
+            val newArray = array.cast(vardeclType)
+            if (newArray != null && newArray != array)
+                return listOf(IAstModification.ReplaceNode(array, newArray, parent))
+        } else {
+            val arrayDt = array.guessDatatype(program)
+            if (arrayDt.isKnown) {
+                val newArray = array.cast(arrayDt.typeOrElse(DataType.STRUCT))
+                if (newArray != null && newArray != array)
+                    return listOf(IAstModification.ReplaceNode(array, newArray, parent))
+            }
+        }
+
+        return noModifications
+    }
+
+    override fun after(functionCall: FunctionCall, parent: Node): Iterable<IAstModification> {
+        // the args of a fuction are constfolded via recursion already.
+        val constvalue = functionCall.constValue(program)
+        return if(constvalue!=null)
+            listOf(IAstModification.ReplaceNode(functionCall, constvalue, parent))
+        else
+            noModifications
+    }
+
+    override fun after(forLoop: ForLoop, parent: Node): Iterable<IAstModification> {
+        fun adjustRangeDt(rangeFrom: NumericLiteralValue, targetDt: DataType, rangeTo: NumericLiteralValue, stepLiteral: NumericLiteralValue?, range: RangeExpr): RangeExpr? {
+            val fromCast = rangeFrom.cast(targetDt)
+            val toCast = rangeTo.cast(targetDt)
+            if(!fromCast.isValid || !toCast.isValid)
+                return null
+
+            val newStep =
+                if(stepLiteral!=null) {
+                    val stepCast = stepLiteral.cast(targetDt)
+                    if(stepCast.isValid)
+                        stepCast.valueOrZero()
+                    else
+                        range.step
+                } else {
+                    range.step
+                }
+
+            return RangeExpr(fromCast.valueOrZero(), toCast.valueOrZero(), newStep, range.position)
+        }
+
+        // adjust the datatype of a range expression in for loops to the loop variable.
+        val iterableRange = forLoop.iterable as? RangeExpr ?: return noModifications
+        val rangeFrom = iterableRange.from as? NumericLiteralValue
+        val rangeTo = iterableRange.to as? NumericLiteralValue
+        if(rangeFrom==null || rangeTo==null) return noModifications
+
+        val loopvar = forLoop.loopVar.targetVarDecl(program.namespace)!!
+        val stepLiteral = iterableRange.step as? NumericLiteralValue
+        when(loopvar.datatype) {
+            DataType.UBYTE -> {
+                if(rangeFrom.type!= DataType.UBYTE) {
+                    // attempt to translate the iterable into ubyte values
+                    val newIter = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
+                    if(newIter!=null)
+                        return listOf(IAstModification.ReplaceNode(forLoop.iterable, newIter, forLoop))
+                }
+            }
+            DataType.BYTE -> {
+                if(rangeFrom.type!= DataType.BYTE) {
+                    // attempt to translate the iterable into byte values
+                    val newIter = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
+                    if(newIter!=null)
+                        return listOf(IAstModification.ReplaceNode(forLoop.iterable, newIter, forLoop))
+                }
+            }
+            DataType.UWORD -> {
+                if(rangeFrom.type!= DataType.UWORD) {
+                    // attempt to translate the iterable into uword values
+                    val newIter = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
+                    if(newIter!=null)
+                        return listOf(IAstModification.ReplaceNode(forLoop.iterable, newIter, forLoop))
+                }
+            }
+            DataType.WORD -> {
+                if(rangeFrom.type!= DataType.WORD) {
+                    // attempt to translate the iterable into word values
+                    val newIter = adjustRangeDt(rangeFrom, loopvar.datatype, rangeTo, stepLiteral, iterableRange)
+                    if(newIter!=null)
+                        return listOf(IAstModification.ReplaceNode(forLoop.iterable, newIter, forLoop))
+                }
+            }
+            else -> throw FatalAstException("invalid loopvar datatype $loopvar")
+        }
+
+        return noModifications
+    }
+
+    override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
+        val numval = decl.value as? NumericLiteralValue
+        if(decl.type== VarDeclType.CONST && numval!=null) {
+            val valueDt = numval.inferType(program)
+            if(!valueDt.istype(decl.datatype)) {
+                val cast = numval.cast(decl.datatype)
+                if(cast.isValid)
+                    return listOf(IAstModification.ReplaceNode(numval, cast.valueOrZero(), decl))
+            }
+        }
+        return noModifications
+    }
+
+    private class ShuffleOperands(val expr: BinaryExpression,
+                                  val exprOperator: String?,
+                                  val subExpr: BinaryExpression,
+                                  val newExprLeft: Expression?,
+                                  val newExprRight: Expression?,
+                                  val newSubexprLeft: Expression?,
+                                  val newSubexprRight: Expression?
+                                  ): IAstModification {
+        override fun perform() {
+            if(exprOperator!=null) expr.operator = exprOperator
+            if(newExprLeft!=null) expr.left = newExprLeft
+            if(newExprRight!=null) expr.right = newExprRight
+            if(newSubexprLeft!=null) subExpr.left = newSubexprLeft
+            if(newSubexprRight!=null) subExpr.right = newSubexprRight
+        }
+    }
+
+    private fun groupTwoConstsTogether(expr: BinaryExpression,
+                                       subExpr: BinaryExpression,
+                                       leftIsConst: Boolean,
+                                       rightIsConst: Boolean,
+                                       subleftIsConst: Boolean,
+                                       subrightIsConst: Boolean): IAstModification?
+    {
+        // todo: this implements only a small set of possible reorderings at this time
+        if(expr.operator==subExpr.operator) {
+            // both operators are the same.
+
+            // If associative,  we can simply shuffle the const operands around to optimize.
+            if(expr.operator in associativeOperators) {
+                return if(leftIsConst) {
+                    if(subleftIsConst)
+                        ShuffleOperands(expr, null, subExpr, subExpr.right, null, null, expr.left)
+                    else
+                        ShuffleOperands(expr, null, subExpr, subExpr.left, null, expr.left, null)
+                } else {
+                    if(subleftIsConst)
+                        ShuffleOperands(expr, null, subExpr, null, subExpr.right, null, expr.right)
+                    else
+                        ShuffleOperands(expr, null, subExpr, null, subExpr.left, expr.right, null)
+                }
+            }
+
+            // If - or /,  we simetimes must reorder more, and flip operators (- -> +, / -> *)
+            if(expr.operator=="-" || expr.operator=="/") {
+                if(leftIsConst) {
+                    return if (subleftIsConst) {
+                        ShuffleOperands(expr, if (expr.operator == "-") "+" else "*", subExpr, subExpr.right, null, expr.left, subExpr.left)
+                    } else {
+                        IAstModification.ReplaceNode(expr,
+                                BinaryExpression(
+                                        BinaryExpression(expr.left, if (expr.operator == "-") "+" else "*", subExpr.right, subExpr.position),
+                                        expr.operator, subExpr.left, expr.position),
+                                expr.parent)
+                    }
+                } else {
+                    return if(subleftIsConst) {
+                        return ShuffleOperands(expr, null, subExpr, null, subExpr.right, null, expr.right)
+                    } else {
+                        IAstModification.ReplaceNode(expr,
+                                BinaryExpression(
+                                        subExpr.left, expr.operator,
+                                        BinaryExpression(expr.right, if (expr.operator == "-") "+" else "*", subExpr.right, subExpr.position),
+                                        expr.position),
+                                expr.parent)
+                    }
+                }
+            }
+            return null
+
+        }
+        else
+        {
+
+            if(expr.operator=="/" && subExpr.operator=="*") {
+                if(leftIsConst) {
+                    val change = if(subleftIsConst) {
+                        // C1/(C2*V) -> (C1/C2)/V
+                        BinaryExpression(
+                                BinaryExpression(expr.left, "/", subExpr.left, subExpr.position),
+                                "/",
+                                subExpr.right, expr.position)
+                    } else {
+                        // C1/(V*C2) -> (C1/C2)/V
+                        BinaryExpression(
+                                BinaryExpression(expr.left, "/", subExpr.right, subExpr.position),
+                                "/",
+                                subExpr.left, expr.position)
+                    }
+                    return IAstModification.ReplaceNode(expr, change, expr.parent)
+                } else {
+                    val change = if(subleftIsConst) {
+                        // (C1*V)/C2 -> (C1/C2)*V
+                        BinaryExpression(
+                                BinaryExpression(subExpr.left, "/", expr.right, subExpr.position),
+                                "*",
+                                subExpr.right, expr.position)
+                    } else {
+                        // (V*C1)/C2 -> (C1/C2)*V
+                        BinaryExpression(
+                                BinaryExpression(subExpr.right, "/", expr.right, subExpr.position),
+                                "*",
+                                subExpr.left, expr.position)
+                    }
+                    return IAstModification.ReplaceNode(expr, change, expr.parent)
+                }
+            }
+            else if(expr.operator=="*" && subExpr.operator=="/") {
+                if(leftIsConst) {
+                    val change = if(subleftIsConst) {
+                        // C1*(C2/V) -> (C1*C2)/V
+                        BinaryExpression(
+                                BinaryExpression(expr.left, "*", subExpr.left, subExpr.position),
+                                "/",
+                                subExpr.right, expr.position)
+                    } else {
+                        // C1*(V/C2) -> (C1/C2)*V
+                        BinaryExpression(
+                                BinaryExpression(expr.left, "/", subExpr.right, subExpr.position),
+                                "*",
+                                subExpr.left, expr.position)
+                    }
+                    return IAstModification.ReplaceNode(expr, change, expr.parent)
+                } else {
+                    val change = if(subleftIsConst) {
+                        // (C1/V)*C2 -> (C1*C2)/V
+                        BinaryExpression(
+                                BinaryExpression(subExpr.left, "*", expr.right, subExpr.position),
+                                "/",
+                                subExpr.right, expr.position)
+                    } else {
+                        // (V/C1)*C2 -> (C1/C2)*V
+                        BinaryExpression(
+                                BinaryExpression(expr.right, "/", subExpr.right, subExpr.position),
+                                "*",
+                                subExpr.left, expr.position)
+                    }
+                    return IAstModification.ReplaceNode(expr, change, expr.parent)
+                }
+            }
+            else if(expr.operator=="+" && subExpr.operator=="-") {
+                if(leftIsConst){
+                    val change = if(subleftIsConst){
+                        // c1+(c2-v)  ->  (c1+c2)-v
+                        BinaryExpression(
+                                BinaryExpression(expr.left, "+", subExpr.left, subExpr.position),
+                                "-",
+                                subExpr.right, expr.position)
+                    } else {
+                        // c1+(v-c2)  ->  v+(c1-c2)
+                        BinaryExpression(
+                                BinaryExpression(expr.left, "-", subExpr.right, subExpr.position),
+                                "+",
+                                subExpr.left, expr.position)
+                    }
+                    return IAstModification.ReplaceNode(expr, change, expr.parent)
+                } else {
+                    val change = if(subleftIsConst) {
+                        // (c1-v)+c2  ->  (c1+c2)-v
+                        BinaryExpression(
+                                BinaryExpression(subExpr.left, "+", expr.right, subExpr.position),
+                                "-",
+                                subExpr.right, expr.position)
+                    } else {
+                        // (v-c1)+c2  ->  v+(c2-c1)
+                        BinaryExpression(
+                                BinaryExpression(expr.right, "-", subExpr.right, subExpr.position),
+                                "+",
+                                subExpr.left, expr.position)
+                    }
+                    return IAstModification.ReplaceNode(expr, change, expr.parent)
+                }
+            }
+            else if(expr.operator=="-" && subExpr.operator=="+") {
+                if(leftIsConst) {
+                    val change = if(subleftIsConst) {
+                        // c1-(c2+v)  ->  (c1-c2)-v
+                        BinaryExpression(
+                                BinaryExpression(expr.left, "-", subExpr.left, subExpr.position),
+                                "-",
+                                subExpr.right, expr.position)
+                    } else {
+                        // c1-(v+c2)  ->  (c1-c2)-v
+                        BinaryExpression(
+                                BinaryExpression(expr.left, "-", subExpr.right, subExpr.position),
+                                "-",
+                                subExpr.left, expr.position)
+                    }
+                    return IAstModification.ReplaceNode(expr, change, expr.parent)
+                } else {
+                    val change = if(subleftIsConst) {
+                        // (c1+v)-c2  ->  v+(c1-c2)
+                        BinaryExpression(
+                                BinaryExpression(subExpr.left, "-", expr.right, subExpr.position),
+                                "+",
+                                subExpr.right, expr.position)
+                    } else {
+                        // (v+c1)-c2  ->  v+(c1-c2)
+                        BinaryExpression(
+                                BinaryExpression(subExpr.right, "-", expr.right, subExpr.position),
+                                "+",
+                                subExpr.left, expr.position)
+                    }
+                    return IAstModification.ReplaceNode(expr, change, expr.parent)
+                }
+            }
+
+            return null
+        }
+    }
+
+}

compiler/src/prog8/optimizer/ConstantIdentifierReplacer.kt

@@ -0,0 +1,192 @@
+package prog8.optimizer
+
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.processing.AstWalker
+import prog8.ast.processing.IAstModification
+import prog8.ast.statements.ArrayIndex
+import prog8.ast.statements.AssignTarget
+import prog8.ast.statements.ForLoop
+import prog8.ast.statements.VarDecl
+import prog8.compiler.target.CompilationTarget
+
+// Fix up the literal value's type to match that of the vardecl
+internal class VarConstantValueTypeAdjuster(private val program: Program) : AstWalker() {
+    private val noModifications = emptyList<IAstModification>()
+
+    override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
+        val declConstValue = decl.value?.constValue(program)
+        if(declConstValue!=null && (decl.type==VarDeclType.VAR || decl.type==VarDeclType.CONST)
+                && !declConstValue.inferType(program).istype(decl.datatype)) {
+            // cast the numeric literal to the appropriate datatype of the variable
+            val cast = declConstValue.cast(decl.datatype)
+            if(cast.isValid)
+                return listOf(IAstModification.ReplaceNode(decl.value!!, cast.valueOrZero(), decl))
+        }
+        return noModifications
+    }
+}
+
+
+// Replace all constant identifiers with their actual value,
+// and the array var initializer values and sizes.
+// This is needed because further constant optimizations depend on those.
+internal class ConstantIdentifierReplacer(private val program: Program, private val errors: ErrorReporter) : AstWalker() {
+    private val noModifications = emptyList<IAstModification>()
+
+    override fun after(identifier: IdentifierReference, parent: Node): Iterable<IAstModification> {
+        // replace identifiers that refer to const value, with the value itself
+        // if it's a simple type and if it's not a left hand side variable
+        if(identifier.parent is AssignTarget)
+            return noModifications
+        var forloop = identifier.parent as? ForLoop
+        if(forloop==null)
+            forloop = identifier.parent.parent as? ForLoop
+        if(forloop!=null && identifier===forloop.loopVar)
+            return noModifications
+
+        val cval = identifier.constValue(program) ?: return noModifications
+        return when (cval.type) {
+            in NumericDatatypes -> listOf(IAstModification.ReplaceNode(identifier, NumericLiteralValue(cval.type, cval.number, identifier.position), identifier.parent))
+            in PassByReferenceDatatypes -> throw FatalAstException("pass-by-reference type should not be considered a constant")
+            else -> noModifications
+        }
+    }
+
+    override fun before(decl: VarDecl, parent: Node): Iterable<IAstModification> {
+        // the initializer value can't refer to the variable itself (recursive definition)
+        // TODO: use call graph for this?
+        if(decl.value?.referencesIdentifier(decl.name) == true || decl.arraysize?.indexVar?.referencesIdentifier(decl.name) == true) {
+            errors.err("recursive var declaration", decl.position)
+            return noModifications
+        }
+
+        if(decl.type== VarDeclType.CONST || decl.type== VarDeclType.VAR) {
+            if(decl.isArray){
+                val arraysize = decl.arraysize
+                if(arraysize==null) {
+                    // for arrays that have no size specifier attempt to deduce the size
+                    val arrayval = decl.value as? ArrayLiteralValue
+                    if(arrayval!=null) {
+                        return listOf(IAstModification.SetExpression(
+                                { decl.arraysize = ArrayIndex(it, decl.position) },
+                                NumericLiteralValue.optimalInteger(arrayval.value.size, decl.position),
+                                decl
+                        ))
+                    }
+                } else if(arraysize.constIndex()==null) {
+                    // see if we can calculate the size from other fields
+                    val cval = arraysize.indexVar?.constValue(program) ?: arraysize.origExpression?.constValue(program)
+                    if(cval!=null) {
+                        arraysize.indexVar = null
+                        arraysize.origExpression = null
+                        arraysize.indexNum = cval
+                    }
+                }
+            }
+
+            when(decl.datatype) {
+                DataType.FLOAT -> {
+                    // vardecl: for scalar float vars, promote constant integer initialization values to floats
+                    val litval = decl.value as? NumericLiteralValue
+                    if (litval!=null && litval.type in IntegerDatatypes) {
+                        val newValue = NumericLiteralValue(DataType.FLOAT, litval.number.toDouble(), litval.position)
+                        return listOf(IAstModification.ReplaceNode(decl.value!!, newValue, decl))
+                    }
+                }
+                DataType.ARRAY_UB, DataType.ARRAY_B, DataType.ARRAY_UW, DataType.ARRAY_W -> {
+                    val numericLv = decl.value as? NumericLiteralValue
+                    val rangeExpr = decl.value as? RangeExpr
+                    if(rangeExpr!=null) {
+                        // convert the initializer range expression to an actual array
+                        val declArraySize = decl.arraysize?.constIndex()
+                        if(declArraySize!=null && declArraySize!=rangeExpr.size())
+                            errors.err("range expression size doesn't match declared array size", decl.value?.position!!)
+                        val constRange = rangeExpr.toConstantIntegerRange()
+                        if(constRange!=null) {
+                            val eltType = rangeExpr.inferType(program).typeOrElse(DataType.UBYTE)
+                            val newValue = if(eltType in ByteDatatypes) {
+                                ArrayLiteralValue(InferredTypes.InferredType.known(decl.datatype),
+                                        constRange.map { NumericLiteralValue(eltType, it.toShort(), decl.value!!.position) }.toTypedArray(),
+                                        position = decl.value!!.position)
+                            } else {
+                                ArrayLiteralValue(InferredTypes.InferredType.known(decl.datatype),
+                                        constRange.map { NumericLiteralValue(eltType, it, decl.value!!.position) }.toTypedArray(),
+                                        position = decl.value!!.position)
+                            }
+                            return listOf(IAstModification.ReplaceNode(decl.value!!, newValue, decl))
+                        }
+                    }
+                    if(numericLv!=null && numericLv.type== DataType.FLOAT)
+                        errors.err("arraysize requires only integers here", numericLv.position)
+                    val size = decl.arraysize?.constIndex() ?: return noModifications
+                    if (rangeExpr==null && numericLv!=null) {
+                        // arraysize initializer is empty or a single int, and we know the size; create the arraysize.
+                        val fillvalue = numericLv.number.toInt()
+                        when(decl.datatype){
+                            DataType.ARRAY_UB -> {
+                                if(fillvalue !in 0..255)
+                                    errors.err("ubyte value overflow", numericLv.position)
+                            }
+                            DataType.ARRAY_B -> {
+                                if(fillvalue !in -128..127)
+                                    errors.err("byte value overflow", numericLv.position)
+                            }
+                            DataType.ARRAY_UW -> {
+                                if(fillvalue !in 0..65535)
+                                    errors.err("uword value overflow", numericLv.position)
+                            }
+                            DataType.ARRAY_W -> {
+                                if(fillvalue !in -32768..32767)
+                                    errors.err("word value overflow", numericLv.position)
+                            }
+                            else -> {}
+                        }
+                        // create the array itself, filled with the fillvalue.
+                        val array = Array(size) {fillvalue}.map { NumericLiteralValue(ArrayElementTypes.getValue(decl.datatype), it, numericLv.position) }.toTypedArray<Expression>()
+                        val refValue = ArrayLiteralValue(InferredTypes.InferredType.known(decl.datatype), array, position = numericLv.position)
+                        return listOf(IAstModification.ReplaceNode(decl.value!!, refValue, decl))
+                    }
+                }
+                DataType.ARRAY_F -> {
+                    val size = decl.arraysize?.constIndex() ?: return noModifications
+                    val litval = decl.value as? NumericLiteralValue
+                    val rangeExpr = decl.value as? RangeExpr
+                    if(rangeExpr!=null) {
+                        // convert the initializer range expression to an actual array of floats
+                        val declArraySize = decl.arraysize?.constIndex()
+                        if(declArraySize!=null && declArraySize!=rangeExpr.size())
+                            errors.err("range expression size doesn't match declared array size", decl.value?.position!!)
+                        val constRange = rangeExpr.toConstantIntegerRange()
+                        if(constRange!=null) {
+                            val newValue = ArrayLiteralValue(InferredTypes.InferredType.known(DataType.ARRAY_F),
+                                    constRange.map { NumericLiteralValue(DataType.FLOAT, it.toDouble(), decl.value!!.position) }.toTypedArray(),
+                                    position = decl.value!!.position)
+                            return listOf(IAstModification.ReplaceNode(decl.value!!, newValue, decl))
+                        }
+                    }
+                    if(rangeExpr==null && litval!=null) {
+                        // arraysize initializer is a single int, and we know the size.
+                        val fillvalue = litval.number.toDouble()
+                        if (fillvalue < CompilationTarget.instance.machine.FLOAT_MAX_NEGATIVE || fillvalue > CompilationTarget.instance.machine.FLOAT_MAX_POSITIVE)
+                            errors.err("float value overflow", litval.position)
+                        else {
+                            // create the array itself, filled with the fillvalue.
+                            val array = Array(size) {fillvalue}.map { NumericLiteralValue(DataType.FLOAT, it, litval.position) }.toTypedArray<Expression>()
+                            val refValue = ArrayLiteralValue(InferredTypes.InferredType.known(DataType.ARRAY_F), array, position = litval.position)
+                            return listOf(IAstModification.ReplaceNode(decl.value!!, refValue, decl))
+                        }
+                    }
+                }
+                else -> {
+                    // nothing to do for this type
+                    // this includes strings and structs
+                }
+            }
+        }
+
+        return noModifications
+    }
+}

compiler/src/prog8/optimizer/ExpressionSimplifier.kt

@@ -0,0 +1,698 @@
+package prog8.optimizer
+
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.base.*
+import prog8.ast.expressions.*
+import prog8.ast.processing.AstWalker
+import prog8.ast.processing.IAstModification
+import kotlin.math.abs
+import kotlin.math.log2
+import kotlin.math.pow
+
+/*
+    todo add more expression optimizations
+
+    Investigate what optimizations binaryen has, also see  https://egorbo.com/peephole-optimizations.html
+
+ */
+
+
+internal class ExpressionSimplifier(private val program: Program) : AstWalker() {
+    private val powersOfTwo = (1..16).map { (2.0).pow(it) }.toSet()
+    private val negativePowersOfTwo = powersOfTwo.map { -it }.toSet()
+    private val noModifications = emptyList<IAstModification>()
+
+    override fun after(typecast: TypecastExpression, parent: Node): Iterable<IAstModification> {
+        val mods = mutableListOf<IAstModification>()
+
+        // try to statically convert a literal value into one of the desired type
+        val literal = typecast.expression as? NumericLiteralValue
+        if (literal != null) {
+            val newLiteral = literal.cast(typecast.type)
+            if (newLiteral.isValid && newLiteral.valueOrZero() !== literal)
+                mods += IAstModification.ReplaceNode(typecast.expression, newLiteral.valueOrZero(), typecast)
+        }
+
+        // remove redundant nested typecasts
+        val subTypecast = typecast.expression as? TypecastExpression
+        if (subTypecast != null) {
+            // remove the sub-typecast if its datatype is larger than the outer typecast
+            if(subTypecast.type largerThan typecast.type) {
+                mods += IAstModification.ReplaceNode(typecast.expression, subTypecast.expression, typecast)
+            }
+        } else {
+            if (typecast.expression.inferType(program).istype(typecast.type)) {
+                // remove duplicate cast
+                mods += IAstModification.ReplaceNode(typecast, typecast.expression, parent)
+            }
+        }
+
+        return mods
+    }
+
+    override fun before(expr: PrefixExpression, parent: Node): Iterable<IAstModification> {
+        if (expr.operator == "+") {
+            // +X --> X
+            return listOf(IAstModification.ReplaceNode(expr, expr.expression, parent))
+        } else if (expr.operator == "not") {
+            when(expr.expression) {
+                is PrefixExpression -> {
+                    // NOT(NOT(...)) -> ...
+                    val pe = expr.expression as PrefixExpression
+                    if(pe.operator == "not")
+                        return listOf(IAstModification.ReplaceNode(expr, pe.expression, parent))
+                }
+                is BinaryExpression -> {
+                    // NOT (xxxx)  ->   invert the xxxx
+                    val be = expr.expression as BinaryExpression
+                    val newExpr = when (be.operator) {
+                        "<" -> BinaryExpression(be.left, ">=", be.right, be.position)
+                        ">" -> BinaryExpression(be.left, "<=", be.right, be.position)
+                        "<=" -> BinaryExpression(be.left, ">", be.right, be.position)
+                        ">=" -> BinaryExpression(be.left, "<", be.right, be.position)
+                        "==" -> BinaryExpression(be.left, "!=", be.right, be.position)
+                        "!=" -> BinaryExpression(be.left, "==", be.right, be.position)
+                        else -> null
+                    }
+
+                    if (newExpr != null)
+                        return listOf(IAstModification.ReplaceNode(expr, newExpr, parent))
+                }
+                else -> return noModifications
+            }
+        }
+        return noModifications
+    }
+
+    override fun after(expr: BinaryExpression, parent: Node): Iterable<IAstModification> {
+        val leftVal = expr.left.constValue(program)
+        val rightVal = expr.right.constValue(program)
+
+        val leftIDt = expr.left.inferType(program)
+        val rightIDt = expr.right.inferType(program)
+        if (!leftIDt.isKnown || !rightIDt.isKnown)
+            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)
+            return listOf(IAstModification.SwapOperands(expr))
+
+        // X + (-A)  -->  X - A
+        if (expr.operator == "+" && (expr.right as? PrefixExpression)?.operator == "-") {
+            return listOf(IAstModification.ReplaceNode(
+                    expr,
+                    BinaryExpression(expr.left, "-", (expr.right as PrefixExpression).expression, expr.position),
+                    parent
+            ))
+        }
+
+        // (-A) + X  -->  X - A
+        if (expr.operator == "+" && (expr.left as? PrefixExpression)?.operator == "-") {
+            return listOf(IAstModification.ReplaceNode(
+                    expr,
+                    BinaryExpression(expr.right, "-", (expr.left as PrefixExpression).expression, expr.position),
+                    parent
+            ))
+        }
+
+        // X - (-A)  -->  X + A
+        if (expr.operator == "-" && (expr.right as? PrefixExpression)?.operator == "-") {
+            return listOf(IAstModification.ReplaceNode(
+                    expr,
+                    BinaryExpression(expr.left, "+", (expr.right as PrefixExpression).expression, expr.position),
+                    parent
+            ))
+        }
+
+        val leftDt = leftIDt.typeOrElse(DataType.STRUCT)
+        val rightDt = rightIDt.typeOrElse(DataType.STRUCT)
+
+        if (expr.operator == "+" || expr.operator == "-"
+                && leftVal == null && rightVal == null
+                && leftDt in NumericDatatypes && rightDt in NumericDatatypes) {
+            val leftBinExpr = expr.left as? BinaryExpression
+            val rightBinExpr = expr.right as? BinaryExpression
+            if (leftBinExpr?.operator == "*") {
+                if (expr.operator == "+") {
+                    // Y*X + X  ->  X*(Y + 1)
+                    // X*Y + X  ->  X*(Y + 1)
+                    val x = expr.right
+                    val y = determineY(x, leftBinExpr)
+                    if (y != null) {
+                        val yPlus1 = BinaryExpression(y, "+", NumericLiteralValue(leftDt, 1, y.position), y.position)
+                        val newExpr = BinaryExpression(x, "*", yPlus1, x.position)
+                        return listOf(IAstModification.ReplaceNode(expr, newExpr, parent))
+                    }
+                } else {
+                    // Y*X - X  ->  X*(Y - 1)
+                    // X*Y - X  ->  X*(Y - 1)
+                    val x = expr.right
+                    val y = determineY(x, leftBinExpr)
+                    if (y != null) {
+                        val yMinus1 = BinaryExpression(y, "-", NumericLiteralValue(leftDt, 1, y.position), y.position)
+                        val newExpr = BinaryExpression(x, "*", yMinus1, x.position)
+                        return listOf(IAstModification.ReplaceNode(expr, newExpr, parent))
+                    }
+                }
+            } else if (rightBinExpr?.operator == "*") {
+                if (expr.operator == "+") {
+                    // X + Y*X  ->  X*(Y + 1)
+                    // X + X*Y  ->  X*(Y + 1)
+                    val x = expr.left
+                    val y = determineY(x, rightBinExpr)
+                    if (y != null) {
+                        val yPlus1 = BinaryExpression(y, "+", NumericLiteralValue.optimalInteger(1, y.position), y.position)
+                        val newExpr = BinaryExpression(x, "*", yPlus1, x.position)
+                        return listOf(IAstModification.ReplaceNode(expr, newExpr, parent))
+                    }
+                }
+            }
+        }
+
+        if(expr.operator == ">=" && rightVal?.number == 0) {
+            if (leftDt == DataType.UBYTE || leftDt == DataType.UWORD) {
+                // unsigned >= 0 --> true
+                return listOf(IAstModification.ReplaceNode(expr, NumericLiteralValue.fromBoolean(true, expr.position), parent))
+            }
+        }
+
+        if(expr.operator == "<" && rightVal?.number == 0) {
+            if (leftDt == DataType.UBYTE || leftDt == DataType.UWORD) {
+                // unsigned < 0 --> false
+                return listOf(IAstModification.ReplaceNode(expr, NumericLiteralValue.fromBoolean(false, expr.position), parent))
+            }
+            when(leftDt) {
+                DataType.BYTE -> {
+                    // signed < 0  -->  signed & $80
+                    return listOf(IAstModification.ReplaceNode(
+                            expr,
+                            BinaryExpression(expr.left, "&", NumericLiteralValue.optimalInteger(0x80, expr.position), expr.position),
+                            parent
+                    ))
+                }
+                DataType.WORD -> {
+                    // signedw < 0 -->  msb(signedw) & $80
+                    return listOf(IAstModification.ReplaceNode(
+                            expr,
+                            BinaryExpression(FunctionCall(IdentifierReference(listOf("msb"), expr.position),
+                                    mutableListOf(expr.left),
+                                    expr.position
+                            ), "&", NumericLiteralValue.optimalInteger(0x80, expr.position), expr.position),
+                            parent
+                    ))
+                }
+                else -> {}
+            }
+        }
+
+        // simplify when a term is constant and directly determines the outcome
+        val constTrue = NumericLiteralValue.fromBoolean(true, expr.position)
+        val constFalse = NumericLiteralValue.fromBoolean(false, expr.position)
+        val newExpr: Expression? = when (expr.operator) {
+            "or" -> {
+                if ((leftVal != null && leftVal.asBooleanValue) || (rightVal != null && rightVal.asBooleanValue))
+                    constTrue
+                else if (leftVal != null && !leftVal.asBooleanValue)
+                    expr.right
+                else if (rightVal != null && !rightVal.asBooleanValue)
+                    expr.left
+                else
+                    null
+            }
+            "and" -> {
+                if ((leftVal != null && !leftVal.asBooleanValue) || (rightVal != null && !rightVal.asBooleanValue))
+                    constFalse
+                else if (leftVal != null && leftVal.asBooleanValue)
+                    expr.right
+                else if (rightVal != null && rightVal.asBooleanValue)
+                    expr.left
+                else
+                    null
+            }
+            "xor" -> {
+                if (leftVal != null && !leftVal.asBooleanValue)
+                    expr.right
+                else if (rightVal != null && !rightVal.asBooleanValue)
+                    expr.left
+                else if (leftVal != null && leftVal.asBooleanValue)
+                    PrefixExpression("not", expr.right, expr.right.position)
+                else if (rightVal != null && rightVal.asBooleanValue)
+                    PrefixExpression("not", expr.left, expr.left.position)
+                else
+                    null
+            }
+            "|", "^" -> {
+                if (leftVal != null && !leftVal.asBooleanValue)
+                    expr.right
+                else if (rightVal != null && !rightVal.asBooleanValue)
+                    expr.left
+                else
+                    null
+            }
+            "&" -> {
+                if (leftVal != null && !leftVal.asBooleanValue)
+                    constFalse
+                else if (rightVal != null && !rightVal.asBooleanValue)
+                    constFalse
+                else
+                    null
+            }
+            "*" -> optimizeMultiplication(expr, leftVal, rightVal)
+            "/" -> optimizeDivision(expr, leftVal, rightVal)
+            "+" -> optimizeAdd(expr, leftVal, rightVal)
+            "-" -> optimizeSub(expr, leftVal, rightVal)
+            "**" -> optimizePower(expr, leftVal, rightVal)
+            "%" -> optimizeRemainder(expr, leftVal, rightVal)
+            ">>" -> optimizeShiftRight(expr, rightVal)
+            "<<" -> optimizeShiftLeft(expr, rightVal)
+            else -> null
+        }
+
+        if(newExpr != null)
+            return listOf(IAstModification.ReplaceNode(expr, newExpr, parent))
+
+        return noModifications
+    }
+
+    override fun after(functionCall: FunctionCall, parent: Node): Iterable<IAstModification> {
+        if(functionCall.target.nameInSource == listOf("lsb")) {
+            val arg = functionCall.args[0]
+            if(arg is TypecastExpression) {
+                val valueDt = arg.expression.inferType(program)
+                if (valueDt.istype(DataType.BYTE) || valueDt.istype(DataType.UBYTE)) {
+                    // useless lsb() of byte value that was casted to word
+                    return listOf(IAstModification.ReplaceNode(functionCall, arg.expression, parent))
+                }
+            } else {
+                val argDt = arg.inferType(program)
+                if (argDt.istype(DataType.BYTE) || argDt.istype(DataType.UBYTE)) {
+                    // useless lsb() of byte value
+                    return listOf(IAstModification.ReplaceNode(functionCall, arg, parent))
+                }
+            }
+        }
+        else if(functionCall.target.nameInSource == listOf("msb")) {
+            val arg = functionCall.args[0]
+            if(arg is TypecastExpression) {
+                val valueDt = arg.expression.inferType(program)
+                if (valueDt.istype(DataType.BYTE) || valueDt.istype(DataType.UBYTE)) {
+                    // useless msb() of byte value that was casted to word, replace with 0
+                    return listOf(IAstModification.ReplaceNode(
+                            functionCall,
+                            NumericLiteralValue(valueDt.typeOrElse(DataType.UBYTE), 0, arg.expression.position),
+                            parent))
+                }
+            } else {
+                val argDt = arg.inferType(program)
+                if (argDt.istype(DataType.BYTE) || argDt.istype(DataType.UBYTE)) {
+                    // useless msb() of byte value, replace with 0
+                    return listOf(IAstModification.ReplaceNode(
+                            functionCall,
+                            NumericLiteralValue(argDt.typeOrElse(DataType.UBYTE), 0, arg.position),
+                            parent))
+                }
+            }
+        }
+
+        return noModifications
+    }
+
+    private fun determineY(x: Expression, subBinExpr: BinaryExpression): Expression? {
+        return when {
+            subBinExpr.left isSameAs x -> subBinExpr.right
+            subBinExpr.right isSameAs x -> subBinExpr.left
+            else -> null
+        }
+    }
+
+    private fun optimizeAdd(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression? {
+        if(expr.left.isSameAs(expr.right)) {
+            // optimize X+X into X *2
+            expr.operator = "*"
+            expr.right = NumericLiteralValue.optimalInteger(2, expr.right.position)
+            expr.right.linkParents(expr)
+            return expr
+        }
+
+        if (leftVal == null && rightVal == null)
+            return null
+
+        val (expr2, _, rightVal2) = reorderAssociative(expr, leftVal)
+        if (rightVal2 != null) {
+            // right value is a constant, see if we can optimize
+            val rightConst: NumericLiteralValue = rightVal2
+            when (rightConst.number.toDouble()) {
+                0.0 -> {
+                    // left
+                    return expr2.left
+                }
+            }
+        }
+        // no need to check for left val constant (because of associativity)
+
+        val rnum = rightVal?.number?.toDouble()
+        if(rnum!=null && rnum<0.0) {
+            expr.operator = "-"
+            expr.right = NumericLiteralValue(rightVal.type, -rnum, rightVal.position)
+            return expr
+        }
+
+        return null
+    }
+
+    private fun optimizeSub(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression? {
+        if(expr.left.isSameAs(expr.right)) {
+            // optimize X-X into 0
+            return NumericLiteralValue.optimalInteger(0, expr.position)
+        }
+
+        if (leftVal == null && rightVal == null)
+            return null
+
+        if (rightVal != null) {
+            // right value is a constant, see if we can optimize
+            val rnum = rightVal.number.toDouble()
+            if (rnum == 0.0) {
+                // left
+                return expr.left
+            }
+
+            if(rnum<0.0) {
+                expr.operator = "+"
+                expr.right = NumericLiteralValue(rightVal.type, -rnum, rightVal.position)
+                return expr
+            }
+        }
+        if (leftVal != null) {
+            // left value is a constant, see if we can optimize
+            when (leftVal.number.toDouble()) {
+                0.0 -> {
+                    // -right
+                    return PrefixExpression("-", expr.right, expr.position)
+                }
+            }
+        }
+
+
+        return null
+    }
+
+    private fun optimizePower(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression? {
+        if (leftVal == null && rightVal == null)
+            return null
+
+        if (rightVal != null) {
+            // right value is a constant, see if we can optimize
+            val rightConst: NumericLiteralValue = rightVal
+            when (rightConst.number.toDouble()) {
+                -3.0 -> {
+                    // -1/(left*left*left)
+                    return BinaryExpression(NumericLiteralValue(DataType.FLOAT, -1.0, expr.position), "/",
+                            BinaryExpression(expr.left, "*", BinaryExpression(expr.left, "*", expr.left, expr.position), expr.position),
+                            expr.position)
+                }
+                -2.0 -> {
+                    // -1/(left*left)
+                    return BinaryExpression(NumericLiteralValue(DataType.FLOAT, -1.0, expr.position), "/",
+                            BinaryExpression(expr.left, "*", expr.left, expr.position),
+                            expr.position)
+                }
+                -1.0 -> {
+                    // -1/left
+                    return BinaryExpression(NumericLiteralValue(DataType.FLOAT, -1.0, expr.position), "/",
+                            expr.left, expr.position)
+                }
+                0.0 -> {
+                    // 1
+                    return NumericLiteralValue(rightConst.type, 1, expr.position)
+                }
+                0.5 -> {
+                    // sqrt(left)
+                    return FunctionCall(IdentifierReference(listOf("sqrt"), expr.position), mutableListOf(expr.left), expr.position)
+                }
+                1.0 -> {
+                    // left
+                    return expr.left
+                }
+                2.0 -> {
+                    // left*left
+                    return BinaryExpression(expr.left, "*", expr.left, expr.position)
+                }
+                3.0 -> {
+                    // left*left*left
+                    return BinaryExpression(expr.left, "*", BinaryExpression(expr.left, "*", expr.left, expr.position), expr.position)
+                }
+            }
+        }
+        if (leftVal != null) {
+            // left value is a constant, see if we can optimize
+            when (leftVal.number.toDouble()) {
+                -1.0 -> {
+                    // -1
+                    return NumericLiteralValue(DataType.FLOAT, -1.0, expr.position)
+                }
+                0.0 -> {
+                    // 0
+                    return NumericLiteralValue(leftVal.type, 0, expr.position)
+                }
+                1.0 -> {
+                    //1
+                    return NumericLiteralValue(leftVal.type, 1, expr.position)
+                }
+
+            }
+        }
+
+        return null
+    }
+
+    private fun optimizeRemainder(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression? {
+        if (leftVal == null && rightVal == null)
+            return null
+
+        // simplify assignments  A = B <operator> C
+
+        val cv = rightVal?.number?.toInt()?.toDouble()
+        when (expr.operator) {
+            "%" -> {
+                if (cv == 1.0) {
+                    val idt = expr.inferType(program)
+                    if(!idt.isKnown)
+                        throw FatalAstException("unknown dt")
+                    return NumericLiteralValue(idt.typeOrElse(DataType.STRUCT), 0, expr.position)
+                } else if (cv == 2.0) {
+                    expr.operator = "&"
+                    expr.right = NumericLiteralValue.optimalInteger(1, expr.position)
+                    return null
+                }
+            }
+        }
+        return null
+
+    }
+
+    private fun optimizeDivision(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression? {
+        if (leftVal == null && rightVal == null)
+            return null
+
+        // cannot shuffle assiciativity with division!
+        if (rightVal != null) {
+            // right value is a constant, see if we can optimize
+            val rightConst: NumericLiteralValue = rightVal
+            val cv = rightConst.number.toDouble()
+            val leftIDt = expr.left.inferType(program)
+            if (!leftIDt.isKnown)
+                return null
+            val leftDt = leftIDt.typeOrElse(DataType.STRUCT)
+            when (cv) {
+                -1.0 -> {
+                    //  '/' -> -left
+                    if (expr.operator == "/") {
+                        return PrefixExpression("-", expr.left, expr.position)
+                    }
+                }
+                1.0 -> {
+                    //  '/' -> left
+                    if (expr.operator == "/") {
+                        return expr.left
+                    }
+                }
+                in powersOfTwo -> {
+                    if (leftDt in IntegerDatatypes) {
+                        // divided by a power of two => shift right
+                        val numshifts = log2(cv).toInt()
+                        return BinaryExpression(expr.left, ">>", NumericLiteralValue.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), ">>", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
+                    }
+                }
+            }
+
+            if (leftDt == DataType.UBYTE) {
+                if (abs(rightConst.number.toDouble()) >= 256.0) {
+                    return NumericLiteralValue(DataType.UBYTE, 0, expr.position)
+                }
+            } else if (leftDt == DataType.UWORD) {
+                if (abs(rightConst.number.toDouble()) >= 65536.0) {
+                    return NumericLiteralValue(DataType.UBYTE, 0, expr.position)
+                }
+            }
+        }
+
+        if (leftVal != null) {
+            // left value is a constant, see if we can optimize
+            when (leftVal.number.toDouble()) {
+                0.0 -> {
+                    // 0
+                    return NumericLiteralValue(leftVal.type, 0, expr.position)
+                }
+            }
+        }
+
+        return null
+    }
+
+    private fun optimizeMultiplication(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression? {
+        if (leftVal == null && rightVal == null)
+            return null
+
+        val (expr2, _, rightVal2) = reorderAssociative(expr, leftVal)
+        if (rightVal2 != null) {
+            // right value is a constant, see if we can optimize
+            val leftValue: Expression = expr2.left
+            val rightConst: NumericLiteralValue = rightVal2
+            when (val cv = rightConst.number.toDouble()) {
+                -1.0 -> {
+                    // -left
+                    return PrefixExpression("-", leftValue, expr.position)
+                }
+                0.0 -> {
+                    // 0
+                    return NumericLiteralValue(rightConst.type, 0, expr.position)
+                }
+                1.0 -> {
+                    // left
+                    return expr2.left
+                }
+                in powersOfTwo -> {
+                    if (leftValue.inferType(program).typeOrElse(DataType.STRUCT) in IntegerDatatypes) {
+                        // times a power of two => shift left
+                        val numshifts = log2(cv).toInt()
+                        return BinaryExpression(expr2.left, "<<", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
+                    }
+                }
+                in negativePowersOfTwo -> {
+                    if (leftValue.inferType(program).typeOrElse(DataType.STRUCT) in IntegerDatatypes) {
+                        // times a negative power of two => negate, then shift left
+                        val numshifts = log2(-cv).toInt()
+                        return BinaryExpression(PrefixExpression("-", expr2.left, expr.position), "<<", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
+                    }
+                }
+            }
+        }
+        // no need to check for left val constant (because of associativity)
+
+        return null
+    }
+
+    private fun optimizeShiftLeft(expr: BinaryExpression, amountLv: NumericLiteralValue?): Expression? {
+        if (amountLv == null)
+            return null
+
+        val amount = amountLv.number.toInt()
+        if (amount == 0) {
+            return expr.left
+        }
+        val targetIDt = expr.left.inferType(program)
+        if(!targetIDt.isKnown)
+            throw FatalAstException("unknown dt")
+        when (val targetDt = targetIDt.typeOrElse(DataType.STRUCT)) {
+            DataType.UBYTE, DataType.BYTE -> {
+                if (amount >= 8) {
+                    return NumericLiteralValue(targetDt, 0, expr.position)
+                }
+            }
+            DataType.UWORD, DataType.WORD -> {
+                if (amount >= 16) {
+                    return NumericLiteralValue(targetDt, 0, expr.position)
+                } else if (amount >= 8) {
+                    val lsb = FunctionCall(IdentifierReference(listOf("lsb"), expr.position), mutableListOf(expr.left), expr.position)
+                    if (amount == 8) {
+                        return FunctionCall(IdentifierReference(listOf("mkword"), expr.position), mutableListOf(lsb, NumericLiteralValue.optimalInteger(0, expr.position)), expr.position)
+                    }
+                    val shifted = BinaryExpression(lsb, "<<", NumericLiteralValue.optimalInteger(amount - 8, expr.position), expr.position)
+                    return FunctionCall(IdentifierReference(listOf("mkword"), expr.position), mutableListOf(shifted, NumericLiteralValue.optimalInteger(0, expr.position)), expr.position)
+                }
+            }
+            else -> {
+            }
+        }
+        return null
+    }
+
+    private fun optimizeShiftRight(expr: BinaryExpression, amountLv: NumericLiteralValue?): Expression? {
+        if (amountLv == null)
+            return null
+
+        val amount = amountLv.number.toInt()
+        if (amount == 0) {
+            return expr.left
+        }
+        val idt = expr.left.inferType(program)
+        if(!idt.isKnown)
+            throw FatalAstException("unknown dt")
+        when (idt.typeOrElse(DataType.STRUCT)) {
+            DataType.UBYTE -> {
+                if (amount >= 8) {
+                    return NumericLiteralValue.optimalInteger(0, expr.position)
+                }
+            }
+            DataType.BYTE -> {
+                if (amount > 8) {
+                    expr.right = NumericLiteralValue.optimalInteger(8, expr.right.position)
+                    return null
+                }
+            }
+            DataType.UWORD -> {
+                if (amount >= 16) {
+                    return NumericLiteralValue.optimalInteger(0, expr.position)
+                } else if (amount >= 8) {
+                    val msb = FunctionCall(IdentifierReference(listOf("msb"), expr.position), mutableListOf(expr.left), expr.position)
+                    if (amount == 8) {
+                        return TypecastExpression(msb, DataType.UWORD, true, expr.position)
+                    }
+                    return BinaryExpression(msb, ">>", NumericLiteralValue.optimalInteger(amount - 8, expr.position), expr.position)
+                }
+            }
+            DataType.WORD -> {
+                if (amount > 16) {
+                    expr.right = NumericLiteralValue.optimalInteger(16, expr.right.position)
+                    return null
+                }
+            }
+            else -> {
+            }
+        }
+        return null
+    }
+
+    private fun reorderAssociative(expr: BinaryExpression, leftVal: NumericLiteralValue?): ReorderedAssociativeBinaryExpr {
+        if (expr.operator in associativeOperators && leftVal != null) {
+            // swap left and right so that right is always the constant
+            val tmp = expr.left
+            expr.left = expr.right
+            expr.right = tmp
+            return ReorderedAssociativeBinaryExpr(expr, expr.right.constValue(program), leftVal)
+        }
+        return ReorderedAssociativeBinaryExpr(expr, leftVal, expr.right.constValue(program))
+    }
+
+    private data class ReorderedAssociativeBinaryExpr(val expr: BinaryExpression, val leftVal: NumericLiteralValue?, val rightVal: NumericLiteralValue?)
+
+}

compiler/src/prog8/optimizer/Extensions.kt

@@ -1,42 +1,61 @@
 package prog8.optimizer
 
 import prog8.ast.Program
-import prog8.ast.base.AstException
-import prog8.parser.ParsingFailedError
+import prog8.ast.base.ErrorReporter
 
 
-internal fun Program.constantFold() {
-    val optimizer = ConstantFolding(this)
-    try {
-        optimizer.visit(this)
-    } catch (ax: AstException) {
-        optimizer.addError(ax)
+internal fun Program.constantFold(errors: ErrorReporter) {
+    val valuetypefixer = VarConstantValueTypeAdjuster(this)
+    valuetypefixer.visit(this)
+    if(errors.isEmpty()) {
+        valuetypefixer.applyModifications()
+
+        val replacer = ConstantIdentifierReplacer(this, errors)
+        replacer.visit(this)
+        if (errors.isEmpty()) {
+            replacer.applyModifications()
+
+            valuetypefixer.visit(this)
+            if(errors.isEmpty()) {
+                valuetypefixer.applyModifications()
+
+                val optimizer = ConstantFoldingOptimizer(this)
+                optimizer.visit(this)
+                while (errors.isEmpty() && optimizer.applyModifications() > 0) {
+                    optimizer.visit(this)
+                }
+
+                if (errors.isEmpty()) {
+                    replacer.visit(this)
+                    replacer.applyModifications()
+                }
+            }
+        }
     }
 
-    while(optimizer.errors.isEmpty() && optimizer.optimizationsDone>0) {
-        optimizer.optimizationsDone = 0
-        optimizer.visit(this)
-    }
-
-    if(optimizer.errors.isNotEmpty()) {
-        optimizer.errors.forEach { System.err.println(it) }
-        throw ParsingFailedError("There are ${optimizer.errors.size} errors.")
-    } else {
+    if(errors.isEmpty())
         modules.forEach { it.linkParents(namespace) }   // re-link in final configuration
-    }
 }
 
 
-internal fun Program.optimizeStatements(): Int {
-    val optimizer = StatementOptimizer(this)
+internal fun Program.optimizeStatements(errors: ErrorReporter): Int {
+    val optimizer = StatementOptimizer(this, errors)
     optimizer.visit(this)
+    val optimizationCount = optimizer.applyModifications()
+
     modules.forEach { it.linkParents(this.namespace) }   // re-link in final configuration
 
-    return optimizer.optimizationsDone
+    return optimizationCount
 }
 
 internal fun Program.simplifyExpressions() : Int {
-    val optimizer = SimplifyExpressions(this)
-    optimizer.visit(this)
-    return optimizer.optimizationsDone
+    val opti = ExpressionSimplifier(this)
+    opti.visit(this)
+    return opti.applyModifications()
+}
+
+internal fun Program.splitBinaryExpressions() : Int {
+    val opti = BinExprSplitter(this)
+    opti.visit(this)
+    return opti.applyModifications()
 }

compiler/src/prog8/optimizer/SimplifyExpressions.kt

@@ -1,828 +0,0 @@
-package prog8.optimizer
-
-import prog8.ast.Program
-import prog8.ast.base.*
-import prog8.ast.expressions.*
-import prog8.ast.processing.IAstModifyingVisitor
-import prog8.ast.statements.Assignment
-import prog8.ast.statements.Statement
-import kotlin.math.abs
-import kotlin.math.log2
-import kotlin.math.pow
-
-/*
-    todo add more expression optimizations
-
-    Also see  https://egorbo.com/peephole-optimizations.html
-
- */
-
-internal class SimplifyExpressions(private val program: Program) : IAstModifyingVisitor {
-    var optimizationsDone: Int = 0
-
-    override fun visit(assignment: Assignment): Statement {
-        if (assignment.aug_op != null)
-            throw AstException("augmented assignments should have been converted to normal assignments before this optimizer")
-        return super.visit(assignment)
-    }
-
-    override fun visit(memread: DirectMemoryRead): Expression {
-        // @( &thing )  -->  thing
-        val addrOf = memread.addressExpression as? AddressOf
-        if(addrOf!=null)
-            return super.visit(addrOf.identifier)
-        return super.visit(memread)
-    }
-
-    override fun visit(typecast: TypecastExpression): Expression {
-        var tc = typecast
-
-        // try to statically convert a literal value into one of the desired type
-        val literal = tc.expression as? NumericLiteralValue
-        if(literal!=null) {
-            val newLiteral = literal.cast(tc.type)
-            if(newLiteral!==literal) {
-                optimizationsDone++
-                return newLiteral
-            }
-        }
-
-        // remove redundant typecasts
-        while(true) {
-            val expr = tc.expression
-            if(expr !is TypecastExpression || expr.type!=tc.type) {
-                val assignment = typecast.parent as? Assignment
-                if(assignment!=null) {
-                    val targetDt = assignment.target.inferType(program, assignment)
-                    if(tc.expression.inferType(program)==targetDt) {
-                        optimizationsDone++
-                        return tc.expression
-                    }
-                }
-
-                val subTc = tc.expression as? TypecastExpression
-                if(subTc!=null) {
-                    // if the previous typecast was casting to a 'bigger' type, just ignore that one
-                    // if the previous typecast was casting to a similar type, ignore that one
-                    if(subTc.type largerThan tc.type || subTc.type equalsSize tc.type) {
-                        subTc.type = tc.type
-                        subTc.parent = tc.parent
-                        optimizationsDone++
-                        return subTc
-                    }
-                }
-
-                return super.visit(tc)
-            }
-
-            optimizationsDone++
-            tc = expr
-        }
-    }
-
-    override fun visit(expr: PrefixExpression): Expression {
-        if (expr.operator == "+") {
-            // +X --> X
-            optimizationsDone++
-            return expr.expression.accept(this)
-        } else if (expr.operator == "not") {
-            (expr.expression as? BinaryExpression)?.let {
-                // NOT (...)  ->   invert  ...
-                when (it.operator) {
-                    "<" -> {
-                        it.operator = ">="
-                        optimizationsDone++
-                        return it
-                    }
-                    ">" -> {
-                        it.operator = "<="
-                        optimizationsDone++
-                        return it
-                    }
-                    "<=" -> {
-                        it.operator = ">"
-                        optimizationsDone++
-                        return it
-                    }
-                    ">=" -> {
-                        it.operator = "<"
-                        optimizationsDone++
-                        return it
-                    }
-                    "==" -> {
-                        it.operator = "!="
-                        optimizationsDone++
-                        return it
-                    }
-                    "!=" -> {
-                        it.operator = "=="
-                        optimizationsDone++
-                        return it
-                    }
-                    else -> {
-                    }
-                }
-            }
-        }
-        return super.visit(expr)
-    }
-
-    override fun visit(expr: BinaryExpression): Expression {
-        super.visit(expr)
-        val leftVal = expr.left.constValue(program)
-        val rightVal = expr.right.constValue(program)
-        val constTrue = NumericLiteralValue.fromBoolean(true, expr.position)
-        val constFalse = NumericLiteralValue.fromBoolean(false, expr.position)
-
-        val leftIDt = expr.left.inferType(program)
-        val rightIDt = expr.right.inferType(program)
-        if(!leftIDt.isKnown || !rightIDt.isKnown)
-            throw FatalAstException("can't determine datatype of both expression operands $expr")
-
-        val leftDt = leftIDt.typeOrElse(DataType.STRUCT)
-        val rightDt = rightIDt.typeOrElse(DataType.STRUCT)
-        if (leftDt != rightDt) {
-            // try to convert a datatype into the other (where ddd
-            if (adjustDatatypes(expr, leftVal, leftDt, rightVal, rightDt)) {
-                optimizationsDone++
-                return expr
-            }
-        }
-
-        // Value <associativeoperator> X -->  X <associativeoperator> Value
-        if (leftVal != null && expr.operator in associativeOperators && rightVal == null) {
-            val tmp = expr.left
-            expr.left = expr.right
-            expr.right = tmp
-            optimizationsDone++
-            return expr
-        }
-
-        // X + (-A)  -->  X - A
-        if (expr.operator == "+" && (expr.right as? PrefixExpression)?.operator == "-") {
-            expr.operator = "-"
-            expr.right = (expr.right as PrefixExpression).expression
-            optimizationsDone++
-            return expr
-        }
-
-        // (-A) + X  -->  X - A
-        if (expr.operator == "+" && (expr.left as? PrefixExpression)?.operator == "-") {
-            expr.operator = "-"
-            val newRight = (expr.left as PrefixExpression).expression
-            expr.left = expr.right
-            expr.right = newRight
-            optimizationsDone++
-            return expr
-        }
-
-        // X + (-value)  -->  X - value
-        if (expr.operator == "+" && rightVal != null) {
-            val rv = rightVal.number.toDouble()
-            if (rv < 0.0) {
-                expr.operator = "-"
-                expr.right = NumericLiteralValue(rightVal.type, -rv, rightVal.position)
-                optimizationsDone++
-                return expr
-            }
-        }
-
-        // (-value) + X  -->  X - value
-        if (expr.operator == "+" && leftVal != null) {
-            val lv = leftVal.number.toDouble()
-            if (lv < 0.0) {
-                expr.operator = "-"
-                expr.right = NumericLiteralValue(leftVal.type, -lv, leftVal.position)
-                optimizationsDone++
-                return expr
-            }
-        }
-
-        // X - (-A)  -->  X + A
-        if (expr.operator == "-" && (expr.right as? PrefixExpression)?.operator == "-") {
-            expr.operator = "+"
-            expr.right = (expr.right as PrefixExpression).expression
-            optimizationsDone++
-            return expr
-        }
-
-        // X - (-value)  -->  X + value
-        if (expr.operator == "-" && rightVal != null) {
-            val rv = rightVal.number.toDouble()
-            if (rv < 0.0) {
-                expr.operator = "+"
-                expr.right = NumericLiteralValue(rightVal.type, -rv, rightVal.position)
-                optimizationsDone++
-                return expr
-            }
-        }
-
-        if (expr.operator == "+" || expr.operator == "-"
-                && leftVal == null && rightVal == null
-                && leftDt in NumericDatatypes && rightDt in NumericDatatypes) {
-            val leftBinExpr = expr.left as? BinaryExpression
-            val rightBinExpr = expr.right as? BinaryExpression
-            if (leftBinExpr?.operator == "*") {
-                if (expr.operator == "+") {
-                    // Y*X + X  ->  X*(Y - 1)
-                    // X*Y + X  ->  X*(Y - 1)
-                    val x = expr.right
-                    val y = determineY(x, leftBinExpr)
-                    if(y!=null) {
-                        val yPlus1 = BinaryExpression(y, "+", NumericLiteralValue(leftDt, 1, y.position), y.position)
-                        return BinaryExpression(x, "*", yPlus1, x.position)
-                    }
-                } else {
-                    // Y*X - X  ->  X*(Y - 1)
-                    // X*Y - X  ->  X*(Y - 1)
-                    val x = expr.right
-                    val y = determineY(x, leftBinExpr)
-                    if(y!=null) {
-                        val yMinus1 = BinaryExpression(y, "-", NumericLiteralValue(leftDt, 1, y.position), y.position)
-                        return BinaryExpression(x, "*", yMinus1, x.position)
-                    }
-                }
-            }
-            else if(rightBinExpr?.operator=="*") {
-                if(expr.operator=="+") {
-                    // X + Y*X  ->  X*(Y + 1)
-                    // X + X*Y  ->  X*(Y + 1)
-                    val x = expr.left
-                    val y = determineY(x, rightBinExpr)
-                    if(y!=null) {
-                        val yPlus1 = BinaryExpression(y, "+", NumericLiteralValue.optimalInteger(1, y.position), y.position)
-                        return BinaryExpression(x, "*", yPlus1, x.position)
-                    }
-                } else {
-                    // X - Y*X  ->  X*(1 - Y)
-                    // X - X*Y  ->  X*(1 - Y)
-                    val x = expr.left
-                    val y = determineY(x, rightBinExpr)
-                    if(y!=null) {
-                        val oneMinusY = BinaryExpression(NumericLiteralValue.optimalInteger(1, y.position), "-", y, y.position)
-                        return BinaryExpression(x, "*", oneMinusY, x.position)
-                    }
-                }
-            }
-        }
-
-
-        // simplify when a term is constant and determines the outcome
-        when (expr.operator) {
-            "or" -> {
-                if ((leftVal != null && leftVal.asBooleanValue) || (rightVal != null && rightVal.asBooleanValue)) {
-                    optimizationsDone++
-                    return constTrue
-                }
-                if (leftVal != null && !leftVal.asBooleanValue) {
-                    optimizationsDone++
-                    return expr.right
-                }
-                if (rightVal != null && !rightVal.asBooleanValue) {
-                    optimizationsDone++
-                    return expr.left
-                }
-            }
-            "and" -> {
-                if ((leftVal != null && !leftVal.asBooleanValue) || (rightVal != null && !rightVal.asBooleanValue)) {
-                    optimizationsDone++
-                    return constFalse
-                }
-                if (leftVal != null && leftVal.asBooleanValue) {
-                    optimizationsDone++
-                    return expr.right
-                }
-                if (rightVal != null && rightVal.asBooleanValue) {
-                    optimizationsDone++
-                    return expr.left
-                }
-            }
-            "xor" -> {
-                if (leftVal != null && !leftVal.asBooleanValue) {
-                    optimizationsDone++
-                    return expr.right
-                }
-                if (rightVal != null && !rightVal.asBooleanValue) {
-                    optimizationsDone++
-                    return expr.left
-                }
-                if (leftVal != null && leftVal.asBooleanValue) {
-                    optimizationsDone++
-                    return PrefixExpression("not", expr.right, expr.right.position)
-                }
-                if (rightVal != null && rightVal.asBooleanValue) {
-                    optimizationsDone++
-                    return PrefixExpression("not", expr.left, expr.left.position)
-                }
-            }
-            "|", "^" -> {
-                if (leftVal != null && !leftVal.asBooleanValue) {
-                    optimizationsDone++
-                    return expr.right
-                }
-                if (rightVal != null && !rightVal.asBooleanValue) {
-                    optimizationsDone++
-                    return expr.left
-                }
-            }
-            "&" -> {
-                if (leftVal != null && !leftVal.asBooleanValue) {
-                    optimizationsDone++
-                    return constFalse
-                }
-                if (rightVal != null && !rightVal.asBooleanValue) {
-                    optimizationsDone++
-                    return constFalse
-                }
-            }
-            "*" -> return optimizeMultiplication(expr, leftVal, rightVal)
-            "/" -> return optimizeDivision(expr, leftVal, rightVal)
-            "+" -> return optimizeAdd(expr, leftVal, rightVal)
-            "-" -> return optimizeSub(expr, leftVal, rightVal)
-            "**" -> return optimizePower(expr, leftVal, rightVal)
-            "%" -> return optimizeRemainder(expr, leftVal, rightVal)
-            ">>" -> return optimizeShiftRight(expr, rightVal)
-            "<<" -> return optimizeShiftLeft(expr, rightVal)
-        }
-        return expr
-    }
-
-    private fun determineY(x: Expression, subBinExpr: BinaryExpression): Expression? {
-        return when {
-            subBinExpr.left isSameAs x -> subBinExpr.right
-            subBinExpr.right isSameAs x -> subBinExpr.left
-            else -> null
-        }
-    }
-
-    private fun adjustDatatypes(expr: BinaryExpression,
-                                leftConstVal: NumericLiteralValue?, leftDt: DataType,
-                                rightConstVal: NumericLiteralValue?, rightDt: DataType): Boolean {
-
-        fun adjust(value: NumericLiteralValue, targetDt: DataType): Pair<Boolean, NumericLiteralValue>{
-            if(value.type==targetDt)
-                return Pair(false, value)
-            when(value.type) {
-                DataType.UBYTE -> {
-                    if (targetDt == DataType.BYTE) {
-                        if(value.number.toInt() < 127)
-                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
-                    }
-                    else if (targetDt == DataType.UWORD || targetDt == DataType.WORD)
-                        return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
-                }
-                DataType.BYTE -> {
-                    if (targetDt == DataType.UBYTE) {
-                        if(value.number.toInt() >= 0)
-                            return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
-                    }
-                    else if (targetDt == DataType.UWORD) {
-                        if(value.number.toInt() >= 0)
-                            return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
-                    }
-                    else if (targetDt == DataType.WORD) return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
-                }
-                DataType.UWORD -> {
-                    if (targetDt == DataType.UBYTE) {
-                        if(value.number.toInt() <= 255)
-                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
-                    }
-                    else if (targetDt == DataType.BYTE) {
-                        if(value.number.toInt() <= 127)
-                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
-                    }
-                    else if (targetDt == DataType.WORD) {
-                        if(value.number.toInt() <= 32767)
-                            return Pair(true, NumericLiteralValue(targetDt, value.number.toInt(), value.position))
-                    }
-                }
-                DataType.WORD -> {
-                    if (targetDt == DataType.UBYTE) {
-                        if(value.number.toInt() in 0..255)
-                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
-                    }
-                    else if (targetDt == DataType.BYTE) {
-                        if(value.number.toInt() in -128..127)
-                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
-                    }
-                    else if (targetDt == DataType.UWORD) {
-                        if(value.number.toInt() >= 0)
-                            return Pair(true, NumericLiteralValue(targetDt, value.number.toShort(), value.position))
-                    }
-                }
-                else -> {}
-            }
-            return Pair(false, value)
-        }
-
-        if(leftConstVal==null && rightConstVal!=null) {
-            if(leftDt largerThan rightDt) {
-                val (adjusted, newValue) = adjust(rightConstVal, leftDt)
-                if (adjusted) {
-                    expr.right = newValue
-                    optimizationsDone++
-                    return true
-                }
-            }
-            return false
-        } else if(leftConstVal!=null && rightConstVal==null) {
-            if(rightDt largerThan leftDt) {
-                val (adjusted, newValue) = adjust(leftConstVal, rightDt)
-                if (adjusted) {
-                    expr.left = newValue
-                    optimizationsDone++
-                    return true
-                }
-            }
-            return false
-        } else {
-            return false    // two const values, don't adjust (should have been const-folded away)
-        }
-    }
-
-    private data class ReorderedAssociativeBinaryExpr(val expr: BinaryExpression, val leftVal: NumericLiteralValue?, val rightVal: NumericLiteralValue?)
-
-    private fun reorderAssociative(expr: BinaryExpression, leftVal: NumericLiteralValue?): ReorderedAssociativeBinaryExpr {
-        if(expr.operator in associativeOperators && leftVal!=null) {
-            // swap left and right so that right is always the constant
-            val tmp = expr.left
-            expr.left = expr.right
-            expr.right = tmp
-            optimizationsDone++
-            return ReorderedAssociativeBinaryExpr(expr, expr.right.constValue(program), leftVal)
-        }
-        return ReorderedAssociativeBinaryExpr(expr, leftVal, expr.right.constValue(program))
-    }
-
-    private fun optimizeAdd(pexpr: BinaryExpression, pleftVal: NumericLiteralValue?, prightVal: NumericLiteralValue?): Expression {
-        if(pleftVal==null && prightVal==null)
-            return pexpr
-
-        val (expr, _, rightVal) = reorderAssociative(pexpr, pleftVal)
-        if(rightVal!=null) {
-            // right value is a constant, see if we can optimize
-            val rightConst: NumericLiteralValue = rightVal
-            when(rightConst.number.toDouble()) {
-                0.0 -> {
-                    // left
-                    optimizationsDone++
-                    return expr.left
-                }
-            }
-        }
-        // no need to check for left val constant (because of associativity)
-
-        return expr
-    }
-
-    private fun optimizeSub(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression {
-        if(leftVal==null && rightVal==null)
-            return expr
-
-        if(rightVal!=null) {
-            // right value is a constant, see if we can optimize
-            val rightConst: NumericLiteralValue = rightVal
-            when(rightConst.number.toDouble()) {
-                0.0 -> {
-                    // left
-                    optimizationsDone++
-                    return expr.left
-                }
-            }
-        }
-        if(leftVal!=null) {
-            // left value is a constant, see if we can optimize
-            when(leftVal.number.toDouble()) {
-                0.0 -> {
-                    // -right
-                    optimizationsDone++
-                    return PrefixExpression("-", expr.right, expr.position)
-                }
-            }
-        }
-
-        return expr
-    }
-
-    private fun optimizePower(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression {
-        if(leftVal==null && rightVal==null)
-            return expr
-
-        if(rightVal!=null) {
-            // right value is a constant, see if we can optimize
-            val rightConst: NumericLiteralValue = rightVal
-            when(rightConst.number.toDouble()) {
-                -3.0 -> {
-                    // -1/(left*left*left)
-                    optimizationsDone++
-                    return BinaryExpression(NumericLiteralValue(DataType.FLOAT, -1.0, expr.position), "/",
-                            BinaryExpression(expr.left, "*", BinaryExpression(expr.left, "*", expr.left, expr.position), expr.position),
-                            expr.position)
-                }
-                -2.0 -> {
-                    // -1/(left*left)
-                    optimizationsDone++
-                    return BinaryExpression(NumericLiteralValue(DataType.FLOAT, -1.0, expr.position), "/",
-                            BinaryExpression(expr.left, "*", expr.left, expr.position),
-                            expr.position)
-                }
-                -1.0 -> {
-                    // -1/left
-                    optimizationsDone++
-                    return BinaryExpression(NumericLiteralValue(DataType.FLOAT, -1.0, expr.position), "/",
-                            expr.left, expr.position)
-                }
-                0.0 -> {
-                    // 1
-                    optimizationsDone++
-                    return NumericLiteralValue(rightConst.type, 1, expr.position)
-                }
-                0.5 -> {
-                    // sqrt(left)
-                    optimizationsDone++
-                    return FunctionCall(IdentifierReference(listOf("sqrt"), expr.position), mutableListOf(expr.left), expr.position)
-                }
-                1.0 -> {
-                    // left
-                    optimizationsDone++
-                    return expr.left
-                }
-                2.0 -> {
-                    // left*left
-                    optimizationsDone++
-                    return BinaryExpression(expr.left, "*", expr.left, expr.position)
-                }
-                3.0 -> {
-                    // left*left*left
-                    optimizationsDone++
-                    return BinaryExpression(expr.left, "*", BinaryExpression(expr.left, "*", expr.left, expr.position), expr.position)
-                }
-            }
-        }
-        if(leftVal!=null) {
-            // left value is a constant, see if we can optimize
-            when(leftVal.number.toDouble()) {
-                -1.0 -> {
-                    // -1
-                    optimizationsDone++
-                    return NumericLiteralValue(DataType.FLOAT, -1.0, expr.position)
-                }
-                0.0 -> {
-                    // 0
-                    optimizationsDone++
-                    return NumericLiteralValue(leftVal.type, 0, expr.position)
-                }
-                1.0 -> {
-                    //1
-                    optimizationsDone++
-                    return NumericLiteralValue(leftVal.type, 1, expr.position)
-                }
-
-            }
-        }
-
-        return expr
-    }
-
-    private fun optimizeRemainder(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression {
-        if(leftVal==null && rightVal==null)
-            return expr
-
-        // simplify assignments  A = B <operator> C
-
-        val cv = rightVal?.number?.toInt()?.toDouble()
-        when(expr.operator) {
-            "%" -> {
-                if (cv == 1.0) {
-                    optimizationsDone++
-                    return NumericLiteralValue(expr.inferType(program).typeOrElse(DataType.STRUCT), 0, expr.position)
-                } else if (cv == 2.0) {
-                    optimizationsDone++
-                    expr.operator = "&"
-                    expr.right = NumericLiteralValue.optimalInteger(1, expr.position)
-                    return expr
-                }
-            }
-        }
-        return expr
-
-    }
-
-    private val powersOfTwo = (1 .. 16).map { (2.0).pow(it) }.toSet()
-    private val negativePowersOfTwo = powersOfTwo.map { -it }.toSet()
-
-    private fun optimizeDivision(expr: BinaryExpression, leftVal: NumericLiteralValue?, rightVal: NumericLiteralValue?): Expression {
-        if(leftVal==null && rightVal==null)
-            return expr
-
-        // cannot shuffle assiciativity with division!
-        if(rightVal!=null) {
-            // right value is a constant, see if we can optimize
-            val rightConst: NumericLiteralValue = rightVal
-            val cv = rightConst.number.toDouble()
-            val leftIDt = expr.left.inferType(program)
-            if(!leftIDt.isKnown)
-                return expr
-            val leftDt = leftIDt.typeOrElse(DataType.STRUCT)
-            when(cv) {
-                -1.0 -> {
-                    //  '/' -> -left
-                    if (expr.operator == "/") {
-                        optimizationsDone++
-                        return PrefixExpression("-", expr.left, expr.position)
-                    }
-                }
-                1.0 -> {
-                    //  '/' -> left
-                    if (expr.operator == "/") {
-                        optimizationsDone++
-                        return expr.left
-                    }
-                }
-                in powersOfTwo -> {
-                    if(leftDt in IntegerDatatypes) {
-                        // divided by a power of two => shift right
-                        optimizationsDone++
-                        val numshifts = log2(cv).toInt()
-                        return BinaryExpression(expr.left, ">>", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
-                    }
-                }
-                in negativePowersOfTwo -> {
-                    if(leftDt in IntegerDatatypes) {
-                        // divided by a negative power of two => negate, then shift right
-                        optimizationsDone++
-                        val numshifts = log2(-cv).toInt()
-                        return BinaryExpression(PrefixExpression("-", expr.left, expr.position), ">>", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
-                    }
-                }
-            }
-
-            if (leftDt == DataType.UBYTE) {
-                if(abs(rightConst.number.toDouble()) >= 256.0) {
-                    optimizationsDone++
-                    return NumericLiteralValue(DataType.UBYTE, 0, expr.position)
-                }
-            }
-            else if (leftDt == DataType.UWORD) {
-                if(abs(rightConst.number.toDouble()) >= 65536.0) {
-                    optimizationsDone++
-                    return NumericLiteralValue(DataType.UBYTE, 0, expr.position)
-                }
-            }
-        }
-
-        if(leftVal!=null) {
-            // left value is a constant, see if we can optimize
-            when(leftVal.number.toDouble()) {
-                0.0 -> {
-                    // 0
-                    optimizationsDone++
-                    return NumericLiteralValue(leftVal.type, 0, expr.position)
-                }
-            }
-        }
-
-        return expr
-    }
-
-    private fun optimizeMultiplication(pexpr: BinaryExpression, pleftVal: NumericLiteralValue?, prightVal: NumericLiteralValue?): Expression {
-        if(pleftVal==null && prightVal==null)
-            return pexpr
-
-        val (expr, _, rightVal) = reorderAssociative(pexpr, pleftVal)
-        if(rightVal!=null) {
-            // right value is a constant, see if we can optimize
-            val leftValue: Expression = expr.left
-            val rightConst: NumericLiteralValue = rightVal
-            when(val cv = rightConst.number.toDouble()) {
-                -1.0 -> {
-                    // -left
-                    optimizationsDone++
-                    return PrefixExpression("-", leftValue, expr.position)
-                }
-                0.0 -> {
-                    // 0
-                    optimizationsDone++
-                    return NumericLiteralValue(rightConst.type, 0, expr.position)
-                }
-                1.0 -> {
-                    // left
-                    optimizationsDone++
-                    return expr.left
-                }
-                in powersOfTwo -> {
-                    if(leftValue.inferType(program).typeOrElse(DataType.STRUCT) in IntegerDatatypes) {
-                        // times a power of two => shift left
-                        optimizationsDone++
-                        val numshifts = log2(cv).toInt()
-                        return BinaryExpression(expr.left, "<<", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
-                    }
-                }
-                in negativePowersOfTwo -> {
-                    if(leftValue.inferType(program).typeOrElse(DataType.STRUCT) in IntegerDatatypes) {
-                        // times a negative power of two => negate, then shift left
-                        optimizationsDone++
-                        val numshifts = log2(-cv).toInt()
-                        return BinaryExpression(PrefixExpression("-", expr.left, expr.position), "<<", NumericLiteralValue.optimalInteger(numshifts, expr.position), expr.position)
-                    }
-                }
-            }
-        }
-        // no need to check for left val constant (because of associativity)
-
-        return expr
-    }
-
-    private fun optimizeShiftLeft(expr: BinaryExpression, amountLv: NumericLiteralValue?): Expression {
-        if(amountLv==null)
-            return expr
-
-        val amount=amountLv.number.toInt()
-        if(amount==0) {
-            optimizationsDone++
-            return expr.left
-        }
-        val targetDt = expr.left.inferType(program).typeOrElse(DataType.STRUCT)
-        when(targetDt) {
-            DataType.UBYTE, DataType.BYTE -> {
-                if(amount>=8) {
-                    optimizationsDone++
-                    return NumericLiteralValue.optimalInteger(0, expr.position)
-                }
-            }
-            DataType.UWORD, DataType.WORD -> {
-                if(amount>=16) {
-                    optimizationsDone++
-                    return NumericLiteralValue.optimalInteger(0, expr.position)
-                }
-                else if(amount>=8) {
-                    optimizationsDone++
-                    val lsb=TypecastExpression(expr.left, DataType.UBYTE, true, expr.position)
-                    if(amount==8) {
-                        return FunctionCall(IdentifierReference(listOf("mkword"), expr.position), mutableListOf(NumericLiteralValue.optimalInteger(0, expr.position), lsb), expr.position)
-                    }
-                    val shifted = BinaryExpression(lsb, "<<", NumericLiteralValue.optimalInteger(amount-8, expr.position), expr.position)
-                    return FunctionCall(IdentifierReference(listOf("mkword"), expr.position), mutableListOf(NumericLiteralValue.optimalInteger(0, expr.position), shifted), expr.position)
-                }
-            }
-            else -> {}
-        }
-        return expr
-    }
-
-    private fun optimizeShiftRight(expr: BinaryExpression, amountLv: NumericLiteralValue?): Expression {
-        if(amountLv==null)
-            return expr
-
-        val amount=amountLv.number.toInt()
-        if(amount==0) {
-            optimizationsDone++
-            return expr.left
-        }
-        val targetDt = expr.left.inferType(program).typeOrElse(DataType.STRUCT)
-        when(targetDt) {
-            DataType.UBYTE -> {
-                if(amount>=8) {
-                    optimizationsDone++
-                    return NumericLiteralValue.optimalInteger(0, expr.position)
-                }
-            }
-            DataType.BYTE -> {
-                if(amount>8) {
-                    expr.right = NumericLiteralValue.optimalInteger(8, expr.right.position)
-                    return expr
-                }
-            }
-            DataType.UWORD -> {
-                if(amount>=16) {
-                    optimizationsDone++
-                    return NumericLiteralValue.optimalInteger(0, expr.position)
-                }
-                else if(amount>=8) {
-                    optimizationsDone++
-                    val msb=FunctionCall(IdentifierReference(listOf("msb"), expr.position), mutableListOf(expr.left), expr.position)
-                    if(amount==8)
-                        return msb
-                    return BinaryExpression(msb, ">>", NumericLiteralValue.optimalInteger(amount-8, expr.position), expr.position)
-                }
-            }
-            DataType.WORD -> {
-                if(amount>16) {
-                    expr.right = NumericLiteralValue.optimalInteger(16, expr.right.position)
-                    return expr
-                } else if(amount>=8) {
-                    optimizationsDone++
-                    val msbAsByte = TypecastExpression(
-                            FunctionCall(IdentifierReference(listOf("msb"), expr.position), mutableListOf(expr.left), expr.position),
-                            DataType.BYTE,
-                            true, expr.position)
-                    if(amount==8)
-                        return msbAsByte
-                    return BinaryExpression(msbAsByte, ">>", NumericLiteralValue.optimalInteger(amount-8, expr.position), expr.position)
-                }
-            }
-            else -> {}
-        }
-        return expr
-    }
-}

compiler/src/prog8/optimizer/StatementOptimizer.kt

@@ -1,12 +1,12 @@
 package prog8.optimizer
 
 import prog8.ast.INameScope
-import prog8.ast.Module
 import prog8.ast.Node
 import prog8.ast.Program
 import prog8.ast.base.*
 import prog8.ast.expressions.*
-import prog8.ast.processing.IAstModifyingVisitor
+import prog8.ast.processing.AstWalker
+import prog8.ast.processing.IAstModification
 import prog8.ast.processing.IAstVisitor
 import prog8.ast.statements.*
 import prog8.compiler.target.CompilationTarget
@@ -14,161 +14,73 @@ import prog8.functions.BuiltinFunctions
 import kotlin.math.floor
 
 
-/*
-    TODO: remove unreachable code?
-    TODO: proper inlining of tiny subroutines (correctly renaming/relocating all variables in them and refs to those as well, or restrict to subs without variables?)
-*/
+internal class StatementOptimizer(private val program: Program,
+                                  private val errors: ErrorReporter) : AstWalker() {
 
-
-internal class StatementOptimizer(private val program: Program) : IAstModifyingVisitor {
-    var optimizationsDone: Int = 0
-        private set
-
-    private val pureBuiltinFunctions = BuiltinFunctions.filter { it.value.pure }
+    private val noModifications = emptyList<IAstModification>()
     private val callgraph = CallGraph(program)
-    private val vardeclsToRemove = mutableListOf<VarDecl>()
+    private val pureBuiltinFunctions = BuiltinFunctions.filter { it.value.pure }
 
-    override fun visit(program: Program) {
-        removeUnusedCode(callgraph)
-        super.visit(program)
-
-        for(decl in vardeclsToRemove) {
-            decl.definingScope().remove(decl)
-        }
-    }
-
-    private fun removeUnusedCode(callgraph: CallGraph) {
-        // remove all subroutines that aren't called, or are empty
-        val removeSubroutines = mutableSetOf<Subroutine>()
-        val entrypoint = program.entrypoint()
-        program.modules.forEach {
-            callgraph.forAllSubroutines(it) { sub ->
-                if (sub !== entrypoint && !sub.keepAlways && (sub.calledBy.isEmpty() || (sub.containsNoCodeNorVars() && !sub.isAsmSubroutine)))
-                    removeSubroutines.add(sub)
-            }
-        }
-
-        if (removeSubroutines.isNotEmpty()) {
-            removeSubroutines.forEach {
-                it.definingScope().remove(it)
-            }
-        }
-
-        val removeBlocks = mutableSetOf<Block>()
-        program.modules.flatMap { it.statements }.filterIsInstance<Block>().forEach { block ->
-            if (block.containsNoCodeNorVars() && "force_output" !in block.options())
-                removeBlocks.add(block)
-        }
-
-        if (removeBlocks.isNotEmpty()) {
-            removeBlocks.forEach { it.definingScope().remove(it) }
-        }
-
-        // remove modules that are not imported, or are empty (unless it's a library modules)
-        val removeModules = mutableSetOf<Module>()
-        program.modules.forEach {
-            if (!it.isLibraryModule && (it.importedBy.isEmpty() || it.containsNoCodeNorVars()))
-                removeModules.add(it)
-        }
-
-        if (removeModules.isNotEmpty()) {
-            program.modules.removeAll(removeModules)
-        }
-    }
-
-    override fun visit(block: Block): Statement {
+    override fun after(block: Block, parent: Node): Iterable<IAstModification> {
         if("force_output" !in block.options()) {
             if (block.containsNoCodeNorVars()) {
-                optimizationsDone++
-                printWarning("removing empty block '${block.name}'", block.position)
-                return NopStatement.insteadOf(block)
+                errors.warn("removing empty block '${block.name}'", block.position)
+                return listOf(IAstModification.Remove(block, parent as INameScope))
             }
 
             if (block !in callgraph.usedSymbols) {
-                optimizationsDone++
-                printWarning("removing unused block '${block.name}'", block.position)
-                return NopStatement.insteadOf(block)  // remove unused block
+                errors.warn("removing unused block '${block.name}'", block.position)
+                return listOf(IAstModification.Remove(block, parent as INameScope))
             }
         }
-
-        return super.visit(block)
+        return noModifications
     }
 
-    override fun visit(subroutine: Subroutine): Statement {
-        super.visit(subroutine)
+    override fun after(subroutine: Subroutine, parent: Node): Iterable<IAstModification> {
         val forceOutput = "force_output" in subroutine.definingBlock().options()
         if(subroutine.asmAddress==null && !forceOutput) {
             if(subroutine.containsNoCodeNorVars()) {
-                printWarning("removing empty subroutine '${subroutine.name}'", subroutine.position)
-                optimizationsDone++
-                return NopStatement.insteadOf(subroutine)
+                errors.warn("removing empty subroutine '${subroutine.name}'", subroutine.position)
+                val removals = callgraph.calledBy.getValue(subroutine).map {
+                    IAstModification.Remove(it, it.definingScope())
+                }.toMutableList()
+                removals += IAstModification.Remove(subroutine, subroutine.definingScope())
+                return removals
             }
         }
 
-        val linesToRemove = deduplicateAssignments(subroutine.statements)
-        if(linesToRemove.isNotEmpty()) {
-            linesToRemove.reversed().forEach{subroutine.statements.removeAt(it)}
-        }
-
         if(subroutine !in callgraph.usedSymbols && !forceOutput) {
-            printWarning("removing unused subroutine '${subroutine.name}'", subroutine.position)
-            optimizationsDone++
-            return NopStatement.insteadOf(subroutine)
+            errors.warn("removing unused subroutine '${subroutine.name}'", subroutine.position)
+            return listOf(IAstModification.Remove(subroutine, subroutine.definingScope()))
         }
 
-        return subroutine
+        return noModifications
     }
 
-    override fun visit(decl: VarDecl): Statement {
+    override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
         val forceOutput = "force_output" in decl.definingBlock().options()
         if(decl !in callgraph.usedSymbols && !forceOutput) {
             if(decl.type == VarDeclType.VAR)
-                printWarning("removing unused variable ${decl.type} '${decl.name}'", decl.position)
-            optimizationsDone++
-            return NopStatement.insteadOf(decl)
+                errors.warn("removing unused variable '${decl.name}'", decl.position)
+
+            return listOf(IAstModification.Remove(decl, decl.definingScope()))
         }
 
-        return super.visit(decl)
+        return noModifications
     }
 
-    private fun deduplicateAssignments(statements: List<Statement>): MutableList<Int> {
-        // removes 'duplicate' assignments that assign the isSameAs target
-        val linesToRemove = mutableListOf<Int>()
-        var previousAssignmentLine: Int? = null
-        for (i in statements.indices) {
-            val stmt = statements[i] as? Assignment
-            if (stmt != null && stmt.value is NumericLiteralValue) {
-                if (previousAssignmentLine == null) {
-                    previousAssignmentLine = i
-                    continue
-                } else {
-                    val prev = statements[previousAssignmentLine] as Assignment
-                    if (prev.target.isSameAs(stmt.target, program)) {
-                        // get rid of the previous assignment, if the target is not MEMORY
-                        if (prev.target.isNotMemory(program.namespace))
-                            linesToRemove.add(previousAssignmentLine)
-                    }
-                    previousAssignmentLine = i
-                }
-            } else
-                previousAssignmentLine = null
-        }
-        return linesToRemove
-    }
-
-    override fun visit(functionCallStatement: FunctionCallStatement): Statement {
+    override fun after(functionCallStatement: FunctionCallStatement, parent: Node): Iterable<IAstModification> {
         if(functionCallStatement.target.nameInSource.size==1 && functionCallStatement.target.nameInSource[0] in BuiltinFunctions) {
             val functionName = functionCallStatement.target.nameInSource[0]
             if (functionName in pureBuiltinFunctions) {
-                printWarning("statement has no effect (function return value is discarded)", functionCallStatement.position)
-                optimizationsDone++
-                return NopStatement.insteadOf(functionCallStatement)
+                errors.warn("statement has no effect (function return value is discarded)", functionCallStatement.position)
+                return listOf(IAstModification.Remove(functionCallStatement, functionCallStatement.definingScope()))
             }
         }
 
-        if(functionCallStatement.target.nameInSource==listOf("c64scr", "print") ||
-                functionCallStatement.target.nameInSource==listOf("c64scr", "print_p")) {
-            // printing a literal string of just 2 or 1 characters is replaced by directly outputting those characters
+        // printing a literal string of just 2 or 1 characters is replaced by directly outputting those characters
+        // this is a C-64 specific optimization
+        if(functionCallStatement.target.nameInSource==listOf("c64scr", "print")) {
             val arg = functionCallStatement.args.single()
             val stringVar: IdentifierReference?
             stringVar = if(arg is AddressOf) {
@@ -178,217 +90,368 @@ internal class StatementOptimizer(private val program: Program) : IAstModifyingV
             }
             if(stringVar!=null) {
                 val vardecl = stringVar.targetVarDecl(program.namespace)!!
-                val string = vardecl.value!! as StringLiteralValue
-                if(string.value.length==1) {
-                    val firstCharEncoded = CompilationTarget.encodeString(string.value)[0]
-                    functionCallStatement.args.clear()
-                    functionCallStatement.args.add(NumericLiteralValue.optimalInteger(firstCharEncoded.toInt(), functionCallStatement.position))
-                    functionCallStatement.target = IdentifierReference(listOf("c64", "CHROUT"), functionCallStatement.target.position)
-                    vardeclsToRemove.add(vardecl)
-                    optimizationsDone++
-                    return functionCallStatement
-                } else if(string.value.length==2) {
-                    val firstTwoCharsEncoded = CompilationTarget.encodeString(string.value.take(2))
-                    val scope = AnonymousScope(mutableListOf(), functionCallStatement.position)
-                    scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("c64", "CHROUT"), functionCallStatement.target.position),
-                            mutableListOf(NumericLiteralValue.optimalInteger(firstTwoCharsEncoded[0].toInt(), functionCallStatement.position)),
-                            functionCallStatement.void, functionCallStatement.position))
-                    scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("c64", "CHROUT"), functionCallStatement.target.position),
-                            mutableListOf(NumericLiteralValue.optimalInteger(firstTwoCharsEncoded[1].toInt(), functionCallStatement.position)),
-                            functionCallStatement.void, functionCallStatement.position))
-                    vardeclsToRemove.add(vardecl)
-                    optimizationsDone++
-                    return scope
+                val string = vardecl.value as? StringLiteralValue
+                if(string!=null) {
+                    val pos = functionCallStatement.position
+                    if (string.value.length == 1) {
+                        val firstCharEncoded = CompilationTarget.instance.encodeString(string.value, string.altEncoding)[0]
+                        val chrout = FunctionCallStatement(
+                                IdentifierReference(listOf("c64", "CHROUT"), pos),
+                                mutableListOf(NumericLiteralValue(DataType.UBYTE, firstCharEncoded.toInt(), pos)),
+                                functionCallStatement.void, pos
+                        )
+                        return listOf(IAstModification.ReplaceNode(functionCallStatement, chrout, parent))
+                    } else if (string.value.length == 2) {
+                        val firstTwoCharsEncoded = CompilationTarget.instance.encodeString(string.value.take(2), string.altEncoding)
+                        val chrout1 = FunctionCallStatement(
+                                IdentifierReference(listOf("c64", "CHROUT"), pos),
+                                mutableListOf(NumericLiteralValue(DataType.UBYTE, firstTwoCharsEncoded[0].toInt(), pos)),
+                                functionCallStatement.void, pos
+                        )
+                        val chrout2 = FunctionCallStatement(
+                                IdentifierReference(listOf("c64", "CHROUT"), pos),
+                                mutableListOf(NumericLiteralValue(DataType.UBYTE, firstTwoCharsEncoded[1].toInt(), pos)),
+                                functionCallStatement.void, pos
+                        )
+                        val anonscope = AnonymousScope(mutableListOf(), pos)
+                        anonscope.statements.add(chrout1)
+                        anonscope.statements.add(chrout2)
+                        return listOf(IAstModification.ReplaceNode(functionCallStatement, anonscope, parent))
+                    }
                 }
             }
         }
 
-        // if it calls a subroutine,
-        // and the first instruction in the subroutine is a jump, call that jump target instead
-        // if the first instruction in the subroutine is a return statement, replace with a nop instruction
+        // if the first instruction in the called subroutine is a return statement, remove the jump altogeter
         val subroutine = functionCallStatement.target.targetSubroutine(program.namespace)
         if(subroutine!=null) {
             val first = subroutine.statements.asSequence().filterNot { it is VarDecl || it is Directive }.firstOrNull()
-            if(first is Jump && first.identifier!=null) {
-                optimizationsDone++
-                return FunctionCallStatement(first.identifier, functionCallStatement.args, functionCallStatement.void, functionCallStatement.position)
-            }
-            if(first is ReturnFromIrq || first is Return) {
-                optimizationsDone++
-                return NopStatement.insteadOf(functionCallStatement)
-            }
+            if(first is Return)
+                return listOf(IAstModification.Remove(functionCallStatement, functionCallStatement.definingScope()))
         }
 
-        return super.visit(functionCallStatement)
+        return noModifications
     }
 
-    override fun visit(functionCall: FunctionCall): Expression {
-        // if it calls a subroutine,
-        // and the first instruction in the subroutine is a jump, call that jump target instead
-        // if the first instruction in the subroutine is a return statement with constant value, replace with the constant value
+    override fun before(functionCall: FunctionCall, parent: Node): Iterable<IAstModification> {
+        // if the first instruction in the called subroutine is a return statement with constant value, replace with the constant value
         val subroutine = functionCall.target.targetSubroutine(program.namespace)
         if(subroutine!=null) {
             val first = subroutine.statements.asSequence().filterNot { it is VarDecl || it is Directive }.firstOrNull()
-            if(first is Jump && first.identifier!=null) {
-                optimizationsDone++
-                return FunctionCall(first.identifier, functionCall.args, functionCall.position)
-            }
             if(first is Return && first.value!=null) {
                 val constval = first.value?.constValue(program)
                 if(constval!=null)
-                    return constval
+                    return listOf(IAstModification.ReplaceNode(functionCall, constval, parent))
             }
         }
-        return super.visit(functionCall)
+        return noModifications
     }
 
-    override fun visit(ifStatement: IfStatement): Statement {
-        super.visit(ifStatement)
-
-        if(ifStatement.truepart.containsNoCodeNorVars() && ifStatement.elsepart.containsNoCodeNorVars()) {
-            optimizationsDone++
-            return NopStatement.insteadOf(ifStatement)
-        }
+    override fun after(ifStatement: IfStatement, parent: Node): Iterable<IAstModification> {
+        // remove empty if statements
+        if(ifStatement.truepart.containsNoCodeNorVars() && ifStatement.elsepart.containsNoCodeNorVars())
+            return listOf(IAstModification.Remove(ifStatement, ifStatement.definingScope()))
 
+        // empty true part? switch with the else part
         if(ifStatement.truepart.containsNoCodeNorVars() && ifStatement.elsepart.containsCodeOrVars()) {
-            // invert the condition and move else part to true part
-            ifStatement.truepart = ifStatement.elsepart
-            ifStatement.elsepart = AnonymousScope(mutableListOf(), ifStatement.elsepart.position)
-            ifStatement.condition = PrefixExpression("not", ifStatement.condition, ifStatement.condition.position)
-            optimizationsDone++
-            return ifStatement
+            val invertedCondition = PrefixExpression("not", ifStatement.condition, ifStatement.condition.position)
+            val emptyscope = AnonymousScope(mutableListOf(), ifStatement.elsepart.position)
+            val truepart = AnonymousScope(ifStatement.elsepart.statements, ifStatement.truepart.position)
+            return listOf(
+                    IAstModification.ReplaceNode(ifStatement.condition, invertedCondition, ifStatement),
+                    IAstModification.ReplaceNode(ifStatement.truepart, truepart, ifStatement),
+                    IAstModification.ReplaceNode(ifStatement.elsepart, emptyscope, ifStatement)
+            )
         }
 
         val constvalue = ifStatement.condition.constValue(program)
         if(constvalue!=null) {
             return if(constvalue.asBooleanValue){
                 // always true -> keep only if-part
-                printWarning("condition is always true", ifStatement.position)  // TODO don't warn this if the condition is just the single value 'true'
-                optimizationsDone++
-                ifStatement.truepart
+                errors.warn("condition is always true", ifStatement.position)
+                listOf(IAstModification.ReplaceNode(ifStatement, ifStatement.truepart, parent))
             } else {
                 // always false -> keep only else-part
-                printWarning("condition is always false", ifStatement.position)
-                optimizationsDone++
-                ifStatement.elsepart
+                errors.warn("condition is always false", ifStatement.position)
+                listOf(IAstModification.ReplaceNode(ifStatement, ifStatement.elsepart, parent))
             }
         }
-        return ifStatement
+
+        return noModifications
     }
 
-    override fun visit(forLoop: ForLoop): Statement {
-        super.visit(forLoop)
+    override fun after(forLoop: ForLoop, parent: Node): Iterable<IAstModification> {
         if(forLoop.body.containsNoCodeNorVars()) {
-            // remove empty for loop
-            optimizationsDone++
-            return NopStatement.insteadOf(forLoop)
+            errors.warn("removing empty for loop", forLoop.position)
+            return listOf(IAstModification.Remove(forLoop, forLoop.definingScope()))
         } else if(forLoop.body.statements.size==1) {
             val loopvar = forLoop.body.statements[0] as? VarDecl
-            if(loopvar!=null && loopvar.name==forLoop.loopVar?.nameInSource?.singleOrNull()) {
-                // remove empty for loop
-                optimizationsDone++
-                return NopStatement.insteadOf(forLoop)
+            if(loopvar!=null && loopvar.name==forLoop.loopVar.nameInSource.singleOrNull()) {
+                // remove empty for loop (only loopvar decl in it)
+                return listOf(IAstModification.Remove(forLoop, forLoop.definingScope()))
             }
         }
 
-
         val range = forLoop.iterable as? RangeExpr
         if(range!=null) {
             if(range.size()==1) {
                 // for loop over a (constant) range of just a single value-- optimize the loop away
                 // loopvar/reg = range value , follow by block
-                val assignment = Assignment(AssignTarget(forLoop.loopRegister, forLoop.loopVar, null, null, forLoop.position), null, range.from, forLoop.position)
-                forLoop.body.statements.add(0, assignment)
-                optimizationsDone++
-                return forLoop.body
+                val scope = AnonymousScope(mutableListOf(), forLoop.position)
+                scope.statements.add(Assignment(AssignTarget(forLoop.loopVar, null, null, forLoop.position), range.from, forLoop.position))
+                scope.statements.addAll(forLoop.body.statements)
+                return listOf(IAstModification.ReplaceNode(forLoop, scope, parent))
             }
         }
-        return forLoop
+        val iterable = (forLoop.iterable as? IdentifierReference)?.targetVarDecl(program.namespace)
+        if(iterable!=null) {
+            if(iterable.datatype==DataType.STR) {
+                val sv = iterable.value as StringLiteralValue
+                val size = sv.value.length
+                if(size==1) {
+                    // loop over string of length 1 -> just assign the single character
+                    val character = CompilationTarget.instance.encodeString(sv.value, sv.altEncoding)[0]
+                    val byte = NumericLiteralValue(DataType.UBYTE, character, iterable.position)
+                    val scope = AnonymousScope(mutableListOf(), forLoop.position)
+                    scope.statements.add(Assignment(AssignTarget(forLoop.loopVar, null, null, forLoop.position), byte, forLoop.position))
+                    scope.statements.addAll(forLoop.body.statements)
+                    return listOf(IAstModification.ReplaceNode(forLoop, scope, parent))
+                }
+            }
+            else if(iterable.datatype in ArrayDatatypes) {
+                val size = iterable.arraysize!!.constIndex()
+                if(size==1) {
+                    // loop over array of length 1 -> just assign the single value
+                    val av = (iterable.value as ArrayLiteralValue).value[0].constValue(program)?.number
+                    if(av!=null) {
+                        val scope = AnonymousScope(mutableListOf(), forLoop.position)
+                        scope.statements.add(Assignment(
+                                AssignTarget(forLoop.loopVar, null, null, forLoop.position), NumericLiteralValue.optimalInteger(av.toInt(), iterable.position),
+                                forLoop.position))
+                        scope.statements.addAll(forLoop.body.statements)
+                        return listOf(IAstModification.ReplaceNode(forLoop, scope, parent))
+                    }
+                }
+            }
+        }
+
+        return noModifications
     }
 
-    override fun visit(whileLoop: WhileLoop): Statement {
-        super.visit(whileLoop)
+    override fun before(untilLoop: UntilLoop, parent: Node): Iterable<IAstModification> {
+        val constvalue = untilLoop.condition.constValue(program)
+        if(constvalue!=null) {
+            if(constvalue.asBooleanValue) {
+                // always true -> keep only the statement block (if there are no break statements)
+                errors.warn("condition is always true", untilLoop.condition.position)
+                if(!hasBreak(untilLoop.body))
+                    return listOf(IAstModification.ReplaceNode(untilLoop, untilLoop.body, parent))
+            } else {
+                // always false
+                val forever = RepeatLoop(null, untilLoop.body, untilLoop.position)
+                return listOf(IAstModification.ReplaceNode(untilLoop, forever, parent))
+            }
+        }
+        return noModifications
+    }
+
+    override fun before(whileLoop: WhileLoop, parent: Node): Iterable<IAstModification> {
         val constvalue = whileLoop.condition.constValue(program)
         if(constvalue!=null) {
-            return if(constvalue.asBooleanValue){
-                // always true -> print a warning, and optimize into body + jump (if there are no continue and break statements)
-                printWarning("condition is always true", whileLoop.condition.position)
-                if(hasContinueOrBreak(whileLoop.body))
-                    return whileLoop
-                val backLabelName = "_prog8_back${whileLoop.position.line}"
-                val label = Label(backLabelName, whileLoop.condition.position)
-                whileLoop.body.statements.add(0, label)
-                whileLoop.body.statements.add(Jump(null,
-                        IdentifierReference(listOf(backLabelName), whileLoop.condition.position),
-                        null, whileLoop.condition.position))
-                optimizationsDone++
-                return whileLoop.body
+            return if(constvalue.asBooleanValue) {
+                // always true
+                val forever = RepeatLoop(null, whileLoop.body, whileLoop.position)
+                listOf(IAstModification.ReplaceNode(whileLoop, forever, parent))
             } else {
-                // always false -> ditch whole statement
-                printWarning("condition is always false", whileLoop.condition.position)
-                optimizationsDone++
-                NopStatement.insteadOf(whileLoop)
+                // always false -> remove the while statement altogether
+                errors.warn("condition is always false", whileLoop.condition.position)
+                listOf(IAstModification.Remove(whileLoop, whileLoop.definingScope()))
             }
         }
-        return whileLoop
+        return noModifications
     }
 
-    override fun visit(repeatLoop: RepeatLoop): Statement {
-        super.visit(repeatLoop)
-        val constvalue = repeatLoop.untilCondition.constValue(program)
-        if(constvalue!=null) {
-            return if(constvalue.asBooleanValue){
-                // always true -> keep only the statement block (if there are no continue and break statements)
-                printWarning("condition is always true", repeatLoop.untilCondition.position)
-                if(hasContinueOrBreak(repeatLoop.body))
-                    repeatLoop
-                else {
-                    optimizationsDone++
-                    repeatLoop.body
-                }
-            } else {
-                // always false -> print a warning, and optimize into body + jump (if there are no continue and break statements)
-                printWarning("condition is always false", repeatLoop.untilCondition.position)
-                if(hasContinueOrBreak(repeatLoop.body))
-                    return repeatLoop
-                val backLabelName = "_prog8_back${repeatLoop.position.line}"
-                val label = Label(backLabelName, repeatLoop.untilCondition.position)
-                repeatLoop.body.statements.add(0, label)
-                repeatLoop.body.statements.add(Jump(null,
-                        IdentifierReference(listOf(backLabelName), repeatLoop.untilCondition.position),
-                        null, repeatLoop.untilCondition.position))
-                optimizationsDone++
-                return repeatLoop.body
+    override fun after(repeatLoop: RepeatLoop, parent: Node): Iterable<IAstModification> {
+        val iter = repeatLoop.iterations
+        if(iter!=null) {
+            if(repeatLoop.body.containsNoCodeNorVars()) {
+                errors.warn("empty loop removed", repeatLoop.position)
+                return listOf(IAstModification.Remove(repeatLoop, repeatLoop.definingScope()))
+            }
+            val iterations = iter.constValue(program)?.number?.toInt()
+            if (iterations == 0) {
+                errors.warn("iterations is always 0, removed loop", iter.position)
+                return listOf(IAstModification.Remove(repeatLoop, repeatLoop.definingScope()))
+            }
+            if (iterations == 1) {
+                errors.warn("iterations is always 1", iter.position)
+                return listOf(IAstModification.ReplaceNode(repeatLoop, repeatLoop.body, parent))
             }
         }
-        return repeatLoop
+        return noModifications
     }
 
-    override fun visit(whenStatement: WhenStatement): Statement {
-        val choices = whenStatement.choices.toList()
-        for(choice in choices) {
-            if(choice.statements.containsNoCodeNorVars())
+    override fun after(whenStatement: WhenStatement, parent: Node): Iterable<IAstModification> {
+        // remove empty choices
+        class ChoiceRemover(val choice: WhenChoice) : IAstModification {
+            override fun perform() {
                 whenStatement.choices.remove(choice)
+            }
         }
-        return super.visit(whenStatement)
+        return whenStatement.choices
+                .filter { !it.statements.containsCodeOrVars() }
+                .map { ChoiceRemover(it) }
     }
 
-    private fun hasContinueOrBreak(scope: INameScope): Boolean {
+    override fun after(jump: Jump, parent: Node): Iterable<IAstModification> {
+        // if the jump is to the next statement, remove the jump
+        val scope = jump.definingScope()
+        val label = jump.identifier?.targetStatement(scope)
+        if(label!=null && scope.statements.indexOf(label) == scope.statements.indexOf(jump)+1)
+            return listOf(IAstModification.Remove(jump, jump.definingScope()))
 
-        class Searcher: IAstModifyingVisitor
+        return noModifications
+    }
+
+    override fun before(assignment: Assignment, parent: Node): Iterable<IAstModification> {
+
+        val binExpr = assignment.value as? BinaryExpression
+        if(binExpr!=null) {
+            if(binExpr.left isSameAs assignment.target) {
+                val rExpr = binExpr.right as? BinaryExpression
+                if(rExpr!=null) {
+                    val op1 = binExpr.operator
+                    val op2 = rExpr.operator
+
+                    if(rExpr.left is NumericLiteralValue && op2 in setOf("+", "*", "&", "|")) {
+                        // associative operator, make sure the constant numeric value is second (right)
+                        return listOf(IAstModification.SwapOperands(rExpr))
+                    }
+
+                    val rNum = (rExpr.right as? NumericLiteralValue)?.number
+                    if(rNum!=null) {
+                        if (op1 == "+" || op1 == "-") {
+                            if (op2 == "+") {
+                                // A = A +/- B + N
+                                val expr2 = BinaryExpression(binExpr.left, binExpr.operator, rExpr.left, binExpr.position)
+                                val addConstant = Assignment(
+                                        assignment.target,
+                                        BinaryExpression(binExpr.left, "+", rExpr.right, rExpr.position),
+                                        assignment.position
+                                )
+                                return listOf(
+                                        IAstModification.ReplaceNode(binExpr, expr2, binExpr.parent),
+                                        IAstModification.InsertAfter(assignment, addConstant, assignment.definingScope()))
+                            } else if (op2 == "-") {
+                                // A = A +/- B - N
+                                val expr2 = BinaryExpression(binExpr.left, binExpr.operator, rExpr.left, binExpr.position)
+                                val subConstant = Assignment(
+                                        assignment.target,
+                                        BinaryExpression(binExpr.left, "-", rExpr.right, rExpr.position),
+                                        assignment.position
+                                )
+                                return listOf(
+                                        IAstModification.ReplaceNode(binExpr, expr2, binExpr.parent),
+                                        IAstModification.InsertAfter(assignment, subConstant, assignment.definingScope()))
+                            }
+                        }
+                    }
+                }
+            }
+
+            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))
+                    return listOf(IAstModification.SwapOperands(binExpr))
+            }
+
+        }
+
+        return noModifications
+    }
+
+    override fun after(assignment: Assignment, parent: Node): Iterable<IAstModification> {
+        if(assignment.target isSameAs assignment.value) {
+            // remove assignment to self
+            return listOf(IAstModification.Remove(assignment, assignment.definingScope()))
+        }
+
+        val targetIDt = assignment.target.inferType(program)
+        if(!targetIDt.isKnown)
+            throw FatalAstException("can't infer type of assignment target")
+
+        // optimize binary expressions a bit
+        val targetDt = targetIDt.typeOrElse(DataType.STRUCT)
+        val bexpr=assignment.value as? BinaryExpression
+        if(bexpr!=null) {
+            val rightCv = bexpr.right.constValue(program)?.number?.toDouble()
+            if (rightCv != null && assignment.target isSameAs bexpr.left) {
+                // assignments of the form:  X = X <operator> <expr>
+                // remove assignments that have no effect (such as X=X+0)
+                // optimize/rewrite some other expressions
+                val vardeclDt = (assignment.target.identifier?.targetVarDecl(program.namespace))?.type
+                when (bexpr.operator) {
+                    "+" -> {
+                        if (rightCv == 0.0) {
+                            return listOf(IAstModification.Remove(assignment, assignment.definingScope()))
+                        } else if (targetDt in IntegerDatatypes && floor(rightCv) == rightCv) {
+                            if (vardeclDt != VarDeclType.MEMORY && rightCv in 1.0..4.0) {
+                                // replace by several INCs if it's not a memory address (inc on a memory mapped register doesn't work very well)
+                                val incs = AnonymousScope(mutableListOf(), assignment.position)
+                                repeat(rightCv.toInt()) {
+                                    incs.statements.add(PostIncrDecr(assignment.target, "++", assignment.position))
+                                }
+                                return listOf(IAstModification.ReplaceNode(assignment, incs, parent))
+                            }
+                        }
+                    }
+                    "-" -> {
+                        if (rightCv == 0.0) {
+                            return listOf(IAstModification.Remove(assignment, assignment.definingScope()))
+                        } else if (targetDt in IntegerDatatypes && floor(rightCv) == rightCv) {
+                            if (vardeclDt != VarDeclType.MEMORY && rightCv in 1.0..4.0) {
+                                // replace by several DECs if it's not a memory address (dec on a memory mapped register doesn't work very well)
+                                val decs = AnonymousScope(mutableListOf(), assignment.position)
+                                repeat(rightCv.toInt()) {
+                                    decs.statements.add(PostIncrDecr(assignment.target, "--", assignment.position))
+                                }
+                                return listOf(IAstModification.ReplaceNode(assignment, decs, parent))
+                            }
+                        }
+                    }
+                    "*" -> if (rightCv == 1.0) return listOf(IAstModification.Remove(assignment, assignment.definingScope()))
+                    "/" -> if (rightCv == 1.0) return listOf(IAstModification.Remove(assignment, assignment.definingScope()))
+                    "**" -> if (rightCv == 1.0) return listOf(IAstModification.Remove(assignment, assignment.definingScope()))
+                    "|" -> if (rightCv == 0.0) return listOf(IAstModification.Remove(assignment, assignment.definingScope()))
+                    "^" -> if (rightCv == 0.0) return listOf(IAstModification.Remove(assignment, assignment.definingScope()))
+                    "<<" -> {
+                        if (rightCv == 0.0)
+                            return listOf(IAstModification.Remove(assignment, assignment.definingScope()))
+                    }
+                    ">>" -> {
+                        if (rightCv == 0.0)
+                            return listOf(IAstModification.Remove(assignment, assignment.definingScope()))
+                    }
+                }
+
+            }
+        }
+
+        return noModifications
+    }
+
+    private fun hasBreak(scope: INameScope): Boolean {
+
+        class Searcher: IAstVisitor
         {
             var count=0
 
-            override fun visit(breakStmt: Break): Statement {
+            override fun visit(breakStmt: Break) {
                 count++
-                return super.visit(breakStmt)
-            }
-
-            override fun visit(contStmt: Continue): Statement {
-                count++
-                return super.visit(contStmt)
             }
         }
+
         val s=Searcher()
         for(stmt in scope.statements) {
             stmt.accept(s)
@@ -398,221 +461,4 @@ internal class StatementOptimizer(private val program: Program) : IAstModifyingV
         return s.count > 0
     }
 
-    override fun visit(jump: Jump): Statement {
-        val subroutine = jump.identifier?.targetSubroutine(program.namespace)
-        if(subroutine!=null) {
-            // if the first instruction in the subroutine is another jump, shortcut this one
-            val first = subroutine.statements.asSequence().filterNot { it is VarDecl || it is Directive }.firstOrNull()
-            if(first is Jump) {
-                optimizationsDone++
-                return first
-            }
-        }
-
-        // if the jump is to the next statement, remove the jump
-        val scope = jump.definingScope()
-        val label = jump.identifier?.targetStatement(scope)
-        if(label!=null) {
-            if(scope.statements.indexOf(label) == scope.statements.indexOf(jump)+1) {
-                optimizationsDone++
-                return NopStatement.insteadOf(jump)
-            }
-        }
-
-        return jump
-    }
-
-    override fun visit(assignment: Assignment): Statement {
-        if(assignment.aug_op!=null)
-            throw AstException("augmented assignments should have been converted to normal assignments before this optimizer")
-
-        if(assignment.target isSameAs assignment.value) {
-            if(assignment.target.isNotMemory(program.namespace)) {
-                optimizationsDone++
-                return NopStatement.insteadOf(assignment)
-            }
-        }
-        val targetIDt = assignment.target.inferType(program, assignment)
-        if(!targetIDt.isKnown)
-            throw FatalAstException("can't infer type of assignment target")
-        val targetDt = targetIDt.typeOrElse(DataType.STRUCT)
-        val bexpr=assignment.value as? BinaryExpression
-        if(bexpr!=null) {
-            val cv = bexpr.right.constValue(program)?.number?.toDouble()
-            if (cv == null) {
-                if (bexpr.operator == "+" && targetDt != DataType.FLOAT) {
-                    if (bexpr.left isSameAs bexpr.right && assignment.target isSameAs bexpr.left) {
-                        bexpr.operator = "*"
-                        bexpr.right = NumericLiteralValue.optimalInteger(2, assignment.value.position)
-                        optimizationsDone++
-                        return assignment
-                    }
-                }
-            } else {
-                if (assignment.target isSameAs bexpr.left) {
-                    // remove assignments that have no effect  X=X , X+=0, X-=0, X*=1, X/=1, X//=1, A |= 0, A ^= 0, A<<=0, etc etc
-                    // A = A <operator> B
-                    val vardeclDt = (assignment.target.identifier?.targetVarDecl(program.namespace))?.type
-
-                    when (bexpr.operator) {
-                        "+" -> {
-                            if (cv == 0.0) {
-                                optimizationsDone++
-                                return NopStatement.insteadOf(assignment)
-                            } else if (targetDt in IntegerDatatypes && floor(cv) == cv) {
-                                if ((vardeclDt == VarDeclType.MEMORY && cv in 1.0..3.0) || (vardeclDt != VarDeclType.MEMORY && cv in 1.0..8.0)) {
-                                    // replace by several INCs (a bit less when dealing with memory targets)
-                                    val decs = AnonymousScope(mutableListOf(), assignment.position)
-                                    repeat(cv.toInt()) {
-                                        decs.statements.add(PostIncrDecr(assignment.target, "++", assignment.position))
-                                    }
-                                    return decs
-                                }
-                            }
-                        }
-                        "-" -> {
-                            if (cv == 0.0) {
-                                optimizationsDone++
-                                return NopStatement.insteadOf(assignment)
-                            } else if (targetDt in IntegerDatatypes && floor(cv) == cv) {
-                                if ((vardeclDt == VarDeclType.MEMORY && cv in 1.0..3.0) || (vardeclDt != VarDeclType.MEMORY && cv in 1.0..8.0)) {
-                                    // replace by several DECs (a bit less when dealing with memory targets)
-                                    val decs = AnonymousScope(mutableListOf(), assignment.position)
-                                    repeat(cv.toInt()) {
-                                        decs.statements.add(PostIncrDecr(assignment.target, "--", assignment.position))
-                                    }
-                                    return decs
-                                }
-                            }
-                        }
-                        "*" -> if (cv == 1.0) {
-                            optimizationsDone++
-                            return NopStatement.insteadOf(assignment)
-                        }
-                        "/" -> if (cv == 1.0) {
-                            optimizationsDone++
-                            return NopStatement.insteadOf(assignment)
-                        }
-                        "**" -> if (cv == 1.0) {
-                            optimizationsDone++
-                            return NopStatement.insteadOf(assignment)
-                        }
-                        "|" -> if (cv == 0.0) {
-                            optimizationsDone++
-                            return NopStatement.insteadOf(assignment)
-                        }
-                        "^" -> if (cv == 0.0) {
-                            optimizationsDone++
-                            return NopStatement.insteadOf(assignment)
-                        }
-                        "<<" -> {
-                            if (cv == 0.0) {
-                                optimizationsDone++
-                                return NopStatement.insteadOf(assignment)
-                            }
-                            if (((targetDt == DataType.UWORD || targetDt == DataType.WORD) && cv > 15.0) ||
-                                    ((targetDt == DataType.UBYTE || targetDt == DataType.BYTE) && cv > 7.0)) {
-                                assignment.value = NumericLiteralValue.optimalInteger(0, assignment.value.position)
-                                assignment.value.linkParents(assignment)
-                                optimizationsDone++
-                            } else {
-                                // replace by in-place lsl(...) call
-                                val scope = AnonymousScope(mutableListOf(), assignment.position)
-                                var numshifts = cv.toInt()
-                                while (numshifts > 0) {
-                                    scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("lsl"), assignment.position),
-                                            mutableListOf(bexpr.left), true, assignment.position))
-                                    numshifts--
-                                }
-                                optimizationsDone++
-                                return scope
-                            }
-                        }
-                        ">>" -> {
-                            if (cv == 0.0) {
-                                optimizationsDone++
-                                return NopStatement.insteadOf(assignment)
-                            }
-                            if ((targetDt == DataType.UWORD && cv > 15.0) || (targetDt == DataType.UBYTE && cv > 7.0)) {
-                                assignment.value = NumericLiteralValue.optimalInteger(0, assignment.value.position)
-                                assignment.value.linkParents(assignment)
-                                optimizationsDone++
-                            } else {
-                                // replace by in-place lsr(...) call
-                                val scope = AnonymousScope(mutableListOf(), assignment.position)
-                                var numshifts = cv.toInt()
-                                while (numshifts > 0) {
-                                    scope.statements.add(FunctionCallStatement(IdentifierReference(listOf("lsr"), assignment.position),
-                                            mutableListOf(bexpr.left), true, assignment.position))
-                                    numshifts--
-                                }
-                                optimizationsDone++
-                                return scope
-                            }
-                        }
-                    }
-                }
-            }
-        }
-
-
-        return super.visit(assignment)
-    }
-
-    override fun visit(scope: AnonymousScope): Statement {
-        val linesToRemove = deduplicateAssignments(scope.statements)
-        if(linesToRemove.isNotEmpty()) {
-            linesToRemove.reversed().forEach{scope.statements.removeAt(it)}
-        }
-        return super.visit(scope)
-    }
-
-    override fun visit(label: Label): Statement {
-        // remove duplicate labels
-        val stmts = label.definingScope().statements
-        val startIdx = stmts.indexOf(label)
-        if(startIdx<(stmts.size-1) && stmts[startIdx+1] == label)
-            return NopStatement.insteadOf(label)
-
-        return super.visit(label)
-    }
-}
-
-
-
-internal class FlattenAnonymousScopesAndRemoveNops: IAstVisitor {
-    private var scopesToFlatten = mutableListOf<INameScope>()
-    private val nopStatements = mutableListOf<NopStatement>()
-
-    override fun visit(program: Program) {
-        super.visit(program)
-        for(scope in scopesToFlatten.reversed()) {
-            val namescope = scope.parent as INameScope
-            val idx = namescope.statements.indexOf(scope as Statement)
-            if(idx>=0) {
-                val nop = NopStatement.insteadOf(namescope.statements[idx])
-                nop.parent = namescope as Node
-                namescope.statements[idx] = nop
-                namescope.statements.addAll(idx, scope.statements)
-                scope.statements.forEach { it.parent = namescope }
-                visit(nop)
-            }
-        }
-
-        this.nopStatements.forEach {
-            it.definingScope().remove(it)
-        }
-    }
-
-    override fun visit(scope: AnonymousScope) {
-        if(scope.parent is INameScope) {
-            scopesToFlatten.add(scope)  // get rid of the anonymous scope
-        }
-
-        return super.visit(scope)
-    }
-
-    override fun visit(nopStatement: NopStatement) {
-        nopStatements.add(nopStatement)
-    }
 }

compiler/src/prog8/optimizer/UnusedCodeRemover.kt

@@ -0,0 +1,103 @@
+package prog8.optimizer
+
+import prog8.ast.INameScope
+import prog8.ast.Node
+import prog8.ast.Program
+import prog8.ast.base.ErrorReporter
+import prog8.ast.processing.AstWalker
+import prog8.ast.processing.IAstModification
+import prog8.ast.statements.*
+
+
+internal class UnusedCodeRemover(private val program: Program, private val errors: ErrorReporter): AstWalker() {
+
+    override fun before(program: Program, parent: Node): Iterable<IAstModification> {
+        val callgraph = CallGraph(program)
+        val removals = mutableListOf<IAstModification>()
+
+        // remove all subroutines that aren't called, or are empty
+        val entrypoint = program.entrypoint()
+        program.modules.forEach {
+            callgraph.forAllSubroutines(it) { sub ->
+                if (sub !== entrypoint && !sub.isAsmSubroutine && (callgraph.calledBy[sub].isNullOrEmpty() || sub.containsNoCodeNorVars())) {
+                    removals.add(IAstModification.Remove(sub, sub.definingScope()))
+                }
+            }
+        }
+
+        program.modules.flatMap { it.statements }.filterIsInstance<Block>().forEach { block ->
+            if (block.containsNoCodeNorVars() && "force_output" !in block.options())
+                removals.add(IAstModification.Remove(block, block.definingScope()))
+        }
+
+        // remove modules that are not imported, or are empty (unless it's a library modules)
+        program.modules.forEach {
+            if (!it.isLibraryModule && (it.importedBy.isEmpty() || it.containsNoCodeNorVars()))
+                removals.add(IAstModification.Remove(it, it.definingScope()))
+        }
+
+        return removals
+    }
+
+
+    override fun before(breakStmt: Break, parent: Node): Iterable<IAstModification> {
+        reportUnreachable(breakStmt, parent as INameScope)
+        return emptyList()
+    }
+
+    override fun before(jump: Jump, parent: Node): Iterable<IAstModification> {
+        reportUnreachable(jump, parent as INameScope)
+        return emptyList()
+    }
+
+    override fun before(returnStmt: Return, parent: Node): Iterable<IAstModification> {
+        reportUnreachable(returnStmt, parent as INameScope)
+        return emptyList()
+    }
+
+    override fun before(functionCallStatement: FunctionCallStatement, parent: Node): Iterable<IAstModification> {
+        if(functionCallStatement.target.nameInSource.last() == "exit")
+            reportUnreachable(functionCallStatement, parent as INameScope)
+        return emptyList()
+    }
+
+    private fun reportUnreachable(stmt: Statement, parent: INameScope) {
+        when(val next = parent.nextSibling(stmt)) {
+            null, is Label, is Directive, is VarDecl, is InlineAssembly, is Subroutine, is StructDecl -> {}
+            else -> errors.warn("unreachable code", next.position)
+        }
+    }
+
+    override fun after(scope: AnonymousScope, parent: Node): Iterable<IAstModification> {
+        val removeDoubleAssignments = deduplicateAssignments(scope.statements)
+        return removeDoubleAssignments.map { IAstModification.Remove(it, scope) }
+    }
+
+    override fun after(block: Block, parent: Node): Iterable<IAstModification> {
+        val removeDoubleAssignments = deduplicateAssignments(block.statements)
+        return removeDoubleAssignments.map { IAstModification.Remove(it, block) }
+    }
+
+    override fun after(subroutine: Subroutine, parent: Node): Iterable<IAstModification> {
+        val removeDoubleAssignments = deduplicateAssignments(subroutine.statements)
+        return removeDoubleAssignments.map { IAstModification.Remove(it, subroutine) }
+    }
+
+    private fun deduplicateAssignments(statements: List<Statement>): List<Assignment> {
+        // removes 'duplicate' assignments that assign the same target directly after another
+        val linesToRemove = mutableListOf<Assignment>()
+
+        for (stmtPairs in statements.windowed(2, step = 1)) {
+            val assign1 = stmtPairs[0] as? Assignment
+            val assign2 = stmtPairs[1] as? Assignment
+            if (assign1 != null && assign2 != null && !assign2.isAugmentable) {
+                if (assign1.target.isSameAs(assign2.target, program) && assign1.target.isInRegularRAM(program.namespace))  {
+                    if(assign2.target.identifier==null || !assign2.value.referencesIdentifier(*(assign2.target.identifier!!.nameInSource.toTypedArray())))
+                        linesToRemove.add(assign1)
+                }
+            }
+        }
+
+        return linesToRemove
+    }
+}

compiler/src/prog8/parser/ModuleParsing.kt

@@ -9,6 +9,7 @@ import prog8.ast.base.SyntaxError
 import prog8.ast.base.checkImportedValid
 import prog8.ast.statements.Directive
 import prog8.ast.statements.DirectiveArg
+import prog8.compiler.target.CompilationTarget
 import prog8.pathFrom
 import java.io.InputStream
 import java.nio.file.Files
@@ -19,128 +20,147 @@ import java.nio.file.Paths
 internal class ParsingFailedError(override var message: String) : Exception(message)
 
 
-private class LexerErrorListener: BaseErrorListener() {
-    var  numberOfErrors: Int = 0
-    override fun syntaxError(p0: Recognizer<*, *>?, p1: Any?, p2: Int, p3: Int, p4: String?, p5: RecognitionException?) {
-        numberOfErrors++
-    }
-}
-
-
 internal class CustomLexer(val modulePath: Path, input: CharStream?) : prog8Lexer(input)
 
 
 internal fun moduleName(fileName: Path) = fileName.toString().substringBeforeLast('.')
 
 
-internal fun importModule(program: Program, filePath: Path): Module {
-    print("importing '${moduleName(filePath.fileName)}'")
-    if(filePath.parent!=null) {
-        var importloc = filePath.toString()
-        val curdir = Paths.get("").toAbsolutePath().toString()
-        if(importloc.startsWith(curdir))
-            importloc = "." + importloc.substring(curdir.length)
-        println(" (from '$importloc')")
-    }
-    else
-        println("")
-    if(!Files.isReadable(filePath))
-        throw ParsingFailedError("No such file: $filePath")
+internal class ModuleImporter {
 
-    val input = CharStreams.fromPath(filePath)
-    return importModule(program, input, filePath, false)
-}
+    internal fun importModule(program: Program, filePath: Path): Module {
+        print("importing '${moduleName(filePath.fileName)}'")
+        if(filePath.parent!=null) {
+            var importloc = filePath.toString()
+            val curdir = Paths.get("").toAbsolutePath().toString()
+            if(importloc.startsWith(curdir))
+                importloc = "." + importloc.substring(curdir.length)
+            println(" (from '$importloc')")
+        }
+        else
+            println("")
+        if(!Files.isReadable(filePath))
+            throw ParsingFailedError("No such file: $filePath")
 
-internal fun importLibraryModule(program: Program, name: String): Module? {
-    val import = Directive("%import", listOf(
-            DirectiveArg("", name, 42, position = Position("<<<implicit-import>>>", 0, 0, 0))
-    ), Position("<<<implicit-import>>>", 0, 0, 0))
-    return executeImportDirective(program, import, Paths.get(""))
-}
-
-internal fun importModule(program: Program, stream: CharStream, modulePath: Path, isLibrary: Boolean): Module {
-    val moduleName = moduleName(modulePath.fileName)
-    val lexer = CustomLexer(modulePath, stream)
-    val lexerErrors = LexerErrorListener()
-    lexer.addErrorListener(lexerErrors)
-    val tokens = CommentHandlingTokenStream(lexer)
-    val parser = prog8Parser(tokens)
-    val parseTree = parser.module()
-    val numberOfErrors = parser.numberOfSyntaxErrors + lexerErrors.numberOfErrors
-    if(numberOfErrors > 0)
-        throw ParsingFailedError("There are $numberOfErrors errors in '$moduleName'.")
-
-    // You can do something with the parsed comments:
-    // tokens.commentTokens().forEach { println(it) }
-
-    // convert to Ast
-    val moduleAst = parseTree.toAst(moduleName, isLibrary, modulePath)
-    moduleAst.program = program
-    moduleAst.linkParents(program.namespace)
-    program.modules.add(moduleAst)
-
-    // accept additional imports
-    val lines = moduleAst.statements.toMutableList()
-    lines.asSequence()
-         .mapIndexed { i, it -> Pair(i, it) }
-         .filter { (it.second as? Directive)?.directive == "%import" }
-         .forEach { executeImportDirective(program, it.second as Directive, modulePath) }
-
-    moduleAst.statements = lines
-    return moduleAst
-}
-
-private fun discoverImportedModuleFile(name: String, source: Path, position: Position?): Path {
-    val fileName = "$name.p8"
-    val locations = mutableListOf(source.parent)
-
-    val propPath = System.getProperty("prog8.libdir")
-    if(propPath!=null)
-        locations.add(pathFrom(propPath))
-    val envPath = System.getenv("PROG8_LIBDIR")
-    if(envPath!=null)
-        locations.add(pathFrom(envPath))
-    locations.add(Paths.get(Paths.get("").toAbsolutePath().toString(), "prog8lib"))
-
-    locations.forEach {
-        val file = pathFrom(it.toString(), fileName)
-        if (Files.isReadable(file)) return file
+        val input = CharStreams.fromPath(filePath)
+        return importModule(program, input, filePath, false)
     }
 
-    throw ParsingFailedError("$position Import: no module source file '$fileName' found  (I've looked in: $locations)")
-}
+    internal fun importLibraryModule(program: Program, name: String): Module? {
+        val import = Directive("%import", listOf(
+                DirectiveArg("", name, 42, position = Position("<<<implicit-import>>>", 0, 0, 0))
+        ), Position("<<<implicit-import>>>", 0, 0, 0))
+        return executeImportDirective(program, import, Paths.get(""))
+    }
 
-private fun executeImportDirective(program: Program, import: Directive, source: Path): Module? {
-    if(import.directive!="%import" || import.args.size!=1 || import.args[0].name==null)
-        throw SyntaxError("invalid import directive", import.position)
-    val moduleName = import.args[0].name!!
-    if("$moduleName.p8" == import.position.file)
-        throw SyntaxError("cannot import self", import.position)
-
-    val existing = program.modules.singleOrNull { it.name == moduleName }
-    if(existing!=null)
-        return null
-
-    val resource = tryGetEmbeddedResource("$moduleName.p8")
-    val importedModule =
-        if(resource!=null) {
-            // load the module from the embedded resource
-            resource.use {
-                if(import.args[0].int==42)
-                    println("importing '$moduleName' (library, auto)")
-                else
-                    println("importing '$moduleName' (library)")
-                importModule(program, CharStreams.fromStream(it), Paths.get("@embedded@/$moduleName"), true)
+    private class MyErrorListener: ConsoleErrorListener() {
+        var  numberOfErrors: Int = 0
+        override fun syntaxError(recognizer: Recognizer<*, *>?, offendingSymbol: Any?, line: Int, charPositionInLine: Int, msg: String, e: RecognitionException?) {
+            numberOfErrors++
+            when (recognizer) {
+                is CustomLexer -> System.err.println("${recognizer.modulePath}:$line:$charPositionInLine: $msg")
+                is prog8Parser -> System.err.println("${recognizer.inputStream.sourceName}:$line:$charPositionInLine: $msg")
+                else -> System.err.println("$line:$charPositionInLine $msg")
             }
-        } else {
-            val modulePath = discoverImportedModuleFile(moduleName, source, import.position)
-            importModule(program, modulePath)
+        }
+    }
+
+    private fun importModule(program: Program, stream: CharStream, modulePath: Path, isLibrary: Boolean): Module {
+        val moduleName = moduleName(modulePath.fileName)
+        val lexer = CustomLexer(modulePath, stream)
+        lexer.removeErrorListeners()
+        val lexerErrors = MyErrorListener()
+        lexer.addErrorListener(lexerErrors)
+        val tokens = CommentHandlingTokenStream(lexer)
+        val parser = prog8Parser(tokens)
+        parser.removeErrorListeners()
+        parser.addErrorListener(MyErrorListener())
+        val parseTree = parser.module()
+        val numberOfErrors = parser.numberOfSyntaxErrors + lexerErrors.numberOfErrors
+        if(numberOfErrors > 0)
+            throw ParsingFailedError("There are $numberOfErrors errors in '$moduleName'.")
+
+        // You can do something with the parsed comments:
+        // tokens.commentTokens().forEach { println(it) }
+
+        // convert to Ast
+        val moduleAst = parseTree.toAst(moduleName, isLibrary, modulePath)
+        moduleAst.program = program
+        moduleAst.linkParents(program.namespace)
+        program.modules.add(moduleAst)
+
+        // accept additional imports
+        val lines = moduleAst.statements.toMutableList()
+        lines.asSequence()
+                .mapIndexed { i, it -> i to it }
+                .filter { (it.second as? Directive)?.directive == "%import" }
+                .forEach { executeImportDirective(program, it.second as Directive, modulePath) }
+
+        moduleAst.statements = lines
+        return moduleAst
+    }
+
+    private fun discoverImportedModuleFile(name: String, source: Path, position: Position?): Path {
+        val fileName = "$name.p8"
+        val locations = if(source.toString().isEmpty()) mutableListOf<Path>() else mutableListOf(source.parent)
+
+        val propPath = System.getProperty("prog8.libdir")
+        if(propPath!=null)
+            locations.add(pathFrom(propPath))
+        val envPath = System.getenv("PROG8_LIBDIR")
+        if(envPath!=null)
+            locations.add(pathFrom(envPath))
+        locations.add(Paths.get(Paths.get("").toAbsolutePath().toString(), "prog8lib"))
+
+        locations.forEach {
+            val file = pathFrom(it.toString(), fileName)
+            if (Files.isReadable(file)) return file
         }
 
-    importedModule.checkImportedValid()
-    return importedModule
-}
+        throw ParsingFailedError("$position Import: no module source file '$fileName' found  (I've looked in: embedded libs and $locations)")
+    }
 
-internal fun tryGetEmbeddedResource(name: String): InputStream? {
-    return object{}.javaClass.getResourceAsStream("/prog8lib/$name")
+    private fun executeImportDirective(program: Program, import: Directive, source: Path): Module? {
+        if(import.directive!="%import" || import.args.size!=1 || import.args[0].name==null)
+            throw SyntaxError("invalid import directive", import.position)
+        val moduleName = import.args[0].name!!
+        if("$moduleName.p8" == import.position.file)
+            throw SyntaxError("cannot import self", import.position)
+
+        val existing = program.modules.singleOrNull { it.name == moduleName }
+        if(existing!=null)
+            return null
+
+        val rsc = tryGetEmbeddedResource("$moduleName.p8")
+        val importedModule =
+                if(rsc!=null) {
+                    // load the module from the embedded resource
+                    val (resource, resourcePath) = rsc
+                    resource.use {
+                        println("importing '$moduleName' (library)")
+                        importModule(program, CharStreams.fromStream(it), Paths.get("@embedded@/$resourcePath"), true)
+                    }
+                } else {
+                    val modulePath = discoverImportedModuleFile(moduleName, source, import.position)
+                    importModule(program, modulePath)
+                }
+
+        importedModule.checkImportedValid()
+        return importedModule
+    }
+
+    private fun tryGetEmbeddedResource(name: String): Pair<InputStream, String>? {
+        val target = CompilationTarget.instance.name
+        val targetSpecificPath = "/prog8lib/$target/$name"
+        val targetSpecificResource = object{}.javaClass.getResourceAsStream(targetSpecificPath)
+        if(targetSpecificResource!=null)
+            return Pair(targetSpecificResource, targetSpecificPath)
+
+        val generalPath = "/prog8lib/$name"
+        val generalResource = object{}.javaClass.getResourceAsStream(generalPath)
+        if(generalResource!=null)
+            return Pair(generalResource, generalPath)
+
+        return null
+    }
 }

compiler/src/prog8/server/dbus/IrmenDbusTest.kt

@@ -0,0 +1,22 @@
+package prog8.server.dbus
+
+//import org.freedesktop.dbus.interfaces.DBusInterface
+//
+//
+//interface IrmenDbusTest: DBusInterface
+//{
+//    fun Status(address: String): Map<Int, String>
+//}
+//
+//
+//internal class TestService: IrmenDbusTest {
+//    override fun Status(address: String): Map<Int, String> {
+//        return mapOf(
+//            5 to "hello",
+//            42 to address
+//        )
+//    }
+//
+//    override fun isRemote() = true
+//    override fun getObjectPath() = "/razorvine/TestService"
+//}

compiler/src/prog8/server/dbus/clientmain.kt

@@ -0,0 +1,17 @@
+package prog8.server.dbus
+
+
+//import org.freedesktop.dbus.connections.impl.DBusConnection
+//
+//
+//fun main() {
+//    DBusConnection.getConnection(DBusConnection.DBusBusType.SESSION).use {
+//        println(it.names.toList())
+//        println(it.uniqueName)
+//        println(it.address)
+//        println(it.machineId)
+//        val obj = it.getRemoteObject("local.net.razorvine.dbus.test", "/razorvine/TestService", IrmenDbusTest::class.java)
+//        println(obj.Status("irmen"))
+//    }
+//}
+//

compiler/src/prog8/server/dbus/testdbus.kt

@@ -0,0 +1,18 @@
+package prog8.server.dbus
+
+//import org.freedesktop.dbus.connections.impl.DBusConnection
+//
+//
+//fun main() {
+//    DBusConnection.getConnection(DBusConnection.DBusBusType.SESSION).use {
+//        it.requestBusName("local.net.razorvine.dbus.test")
+//        println(it.names.toList())
+//        println(it.uniqueName)
+//        println(it.address)
+//        println(it.machineId)
+//        val service = TestService()
+//        it.exportObject(service.objectPath, service)
+//
+//        Thread.sleep(100000)
+//    }
+//}

compiler/src/prog8/vm/RuntimeValue.kt

@@ -1,658 +0,0 @@
-package prog8.vm
-
-import prog8.ast.base.ByteDatatypes
-import prog8.ast.base.DataType
-import prog8.ast.base.WordDatatypes
-import prog8.ast.expressions.ArrayLiteralValue
-import prog8.ast.expressions.NumericLiteralValue
-import prog8.ast.expressions.StringLiteralValue
-import prog8.vm.astvm.VmExecutionException
-import java.util.Objects
-import kotlin.math.abs
-import kotlin.math.pow
-
-
-/**
- * Rather than a literal value (NumericLiteralValue) that occurs in the parsed source code,
- * this runtime value can be used to *execute* the parsed Ast (or another intermediary form)
- * It contains a value of a variable during run time of the program and provides arithmetic operations on the value.
- */
-
-abstract class RuntimeValueBase(val type: DataType) {
-    abstract fun numericValue(): Number
-    abstract fun integerValue(): Int
-}
-
-
-class RuntimeValueNumeric(type: DataType, num: Number): RuntimeValueBase(type) {
-
-    val byteval: Short?
-    val wordval: Int?
-    val floatval: Double?
-    val asBoolean: Boolean
-
-    companion object {
-        fun fromLv(literalValue: NumericLiteralValue): RuntimeValueNumeric {
-            return RuntimeValueNumeric(literalValue.type, num = literalValue.number)
-        }
-    }
-
-    init {
-        when (type) {
-            DataType.UBYTE -> {
-                val inum = num.toInt()
-                require(inum in 0..255) { "invalid value for ubyte: $inum" }
-                byteval = inum.toShort()
-                wordval = null
-                floatval = null
-                asBoolean = byteval != 0.toShort()
-            }
-            DataType.BYTE -> {
-                val inum = num.toInt()
-                require(inum in -128..127) { "invalid value for byte: $inum" }
-                byteval = inum.toShort()
-                wordval = null
-                floatval = null
-                asBoolean = byteval != 0.toShort()
-            }
-            DataType.UWORD -> {
-                val inum = num.toInt()
-                require(inum in 0..65535) { "invalid value for uword: $inum" }
-                wordval = inum
-                byteval = null
-                floatval = null
-                asBoolean = wordval != 0
-            }
-            DataType.WORD -> {
-                val inum = num.toInt()
-                require(inum in -32768..32767) { "invalid value for word: $inum" }
-                wordval = inum
-                byteval = null
-                floatval = null
-                asBoolean = wordval != 0
-            }
-            DataType.FLOAT -> {
-                floatval = num.toDouble()
-                byteval = null
-                wordval = null
-                asBoolean = floatval != 0.0
-            }
-            else -> throw VmExecutionException("not a numeric value")
-        }
-    }
-
-    override fun toString(): String {
-        return when (type) {
-            DataType.UBYTE -> "ub:%02x".format(byteval)
-            DataType.BYTE -> {
-                if (byteval!! < 0)
-                    "b:-%02x".format(abs(byteval.toInt()))
-                else
-                    "b:%02x".format(byteval)
-            }
-            DataType.UWORD -> "uw:%04x".format(wordval)
-            DataType.WORD -> {
-                if (wordval!! < 0)
-                    "w:-%04x".format(abs(wordval))
-                else
-                    "w:%04x".format(wordval)
-            }
-            DataType.FLOAT -> "f:$floatval"
-            else -> "???"
-        }
-    }
-
-    override fun numericValue(): Number {
-        return when (type) {
-            in ByteDatatypes -> byteval!!
-            in WordDatatypes -> wordval!!
-            DataType.FLOAT -> floatval!!
-            else -> throw ArithmeticException("invalid datatype for numeric value: $type")
-        }
-    }
-
-    override fun integerValue(): Int {
-        return when (type) {
-            in ByteDatatypes -> byteval!!.toInt()
-            in WordDatatypes -> wordval!!
-            DataType.FLOAT -> throw ArithmeticException("float to integer loss of precision")
-            else -> throw ArithmeticException("invalid datatype for integer value: $type")
-        }
-    }
-
-    override fun hashCode(): Int = Objects.hash(byteval, wordval, floatval, type)
-
-    override fun equals(other: Any?): Boolean {
-        if (other == null || other !is RuntimeValueNumeric)
-            return false
-        return compareTo(other) == 0      // note: datatype doesn't matter
-    }
-
-    operator fun compareTo(other: RuntimeValueNumeric): Int = numericValue().toDouble().compareTo(other.numericValue().toDouble())
-
-    private fun arithResult(leftDt: DataType, result: Number, rightDt: DataType, op: String): RuntimeValueNumeric {
-        if (leftDt != rightDt)
-            throw ArithmeticException("left and right datatypes are not the same")
-        if (result.toDouble() < 0) {
-            return when (leftDt) {
-                DataType.UBYTE, DataType.UWORD -> {
-                    // storing a negative number in an unsigned one is done by storing the 2's complement instead
-                    val number = abs(result.toDouble().toInt())
-                    if (leftDt == DataType.UBYTE)
-                        RuntimeValueNumeric(DataType.UBYTE, (number xor 255) + 1)
-                    else
-                        RuntimeValueNumeric(DataType.UWORD, (number xor 65535) + 1)
-                }
-                DataType.BYTE -> {
-                    val v = result.toInt() and 255
-                    if (v < 128)
-                        RuntimeValueNumeric(DataType.BYTE, v)
-                    else
-                        RuntimeValueNumeric(DataType.BYTE, v - 256)
-                }
-                DataType.WORD -> {
-                    val v = result.toInt() and 65535
-                    if (v < 32768)
-                        RuntimeValueNumeric(DataType.WORD, v)
-                    else
-                        RuntimeValueNumeric(DataType.WORD, v - 65536)
-                }
-                DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, result)
-                else -> throw ArithmeticException("$op on non-numeric type")
-            }
-        }
-
-        return when (leftDt) {
-            DataType.UBYTE -> RuntimeValueNumeric(DataType.UBYTE, result.toInt() and 255)
-            DataType.BYTE -> {
-                val v = result.toInt() and 255
-                if (v < 128)
-                    RuntimeValueNumeric(DataType.BYTE, v)
-                else
-                    RuntimeValueNumeric(DataType.BYTE, v - 256)
-            }
-            DataType.UWORD -> RuntimeValueNumeric(DataType.UWORD, result.toInt() and 65535)
-            DataType.WORD -> {
-                val v = result.toInt() and 65535
-                if (v < 32768)
-                    RuntimeValueNumeric(DataType.WORD, v)
-                else
-                    RuntimeValueNumeric(DataType.WORD, v - 65536)
-            }
-            DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, result)
-            else -> throw ArithmeticException("$op on non-numeric type")
-        }
-    }
-
-    fun add(other: RuntimeValueNumeric): RuntimeValueNumeric {
-        if (other.type == DataType.FLOAT && (type != DataType.FLOAT))
-            throw ArithmeticException("floating point loss of precision on type $type")
-        val v1 = numericValue()
-        val v2 = other.numericValue()
-        val result = v1.toDouble() + v2.toDouble()
-        return arithResult(type, result, other.type, "add")
-    }
-
-    fun sub(other: RuntimeValueNumeric): RuntimeValueNumeric {
-        if (other.type == DataType.FLOAT && (type != DataType.FLOAT))
-            throw ArithmeticException("floating point loss of precision on type $type")
-        val v1 = numericValue()
-        val v2 = other.numericValue()
-        val result = v1.toDouble() - v2.toDouble()
-        return arithResult(type, result, other.type, "sub")
-    }
-
-    fun mul(other: RuntimeValueNumeric): RuntimeValueNumeric {
-        if (other.type == DataType.FLOAT && (type != DataType.FLOAT))
-            throw ArithmeticException("floating point loss of precision on type $type")
-        val v1 = numericValue()
-        val v2 = other.numericValue()
-        val result = v1.toDouble() * v2.toDouble()
-        return arithResult(type, result, other.type, "mul")
-    }
-
-    fun div(other: RuntimeValueNumeric): RuntimeValueNumeric {
-        if (other.type == DataType.FLOAT && (type != DataType.FLOAT))
-            throw ArithmeticException("floating point loss of precision on type $type")
-        val v1 = numericValue()
-        val v2 = other.numericValue()
-        if (v2.toDouble() == 0.0) {
-            when (type) {
-                DataType.UBYTE -> return RuntimeValueNumeric(DataType.UBYTE, 255)
-                DataType.BYTE -> return RuntimeValueNumeric(DataType.BYTE, 127)
-                DataType.UWORD -> return RuntimeValueNumeric(DataType.UWORD, 65535)
-                DataType.WORD -> return RuntimeValueNumeric(DataType.WORD, 32767)
-                else -> {
-                }
-            }
-        }
-        val result = v1.toDouble() / v2.toDouble()
-        // NOTE: integer division returns integer result!
-        return when (type) {
-            DataType.UBYTE -> RuntimeValueNumeric(DataType.UBYTE, result)
-            DataType.BYTE -> RuntimeValueNumeric(DataType.BYTE, result)
-            DataType.UWORD -> RuntimeValueNumeric(DataType.UWORD, result)
-            DataType.WORD -> RuntimeValueNumeric(DataType.WORD, result)
-            DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, result)
-            else -> throw ArithmeticException("div on non-numeric type")
-        }
-    }
-
-    fun remainder(other: RuntimeValueNumeric): RuntimeValueNumeric {
-        val v1 = numericValue()
-        val v2 = other.numericValue()
-        val result = v1.toDouble() % v2.toDouble()
-        return arithResult(type, result, other.type, "remainder")
-    }
-
-    fun pow(other: RuntimeValueNumeric): RuntimeValueNumeric {
-        val v1 = numericValue()
-        val v2 = other.numericValue()
-        val result = v1.toDouble().pow(v2.toDouble())
-        return arithResult(type, result, other.type, "pow")
-    }
-
-    fun shl(): RuntimeValueNumeric {
-        val v = integerValue()
-        return when (type) {
-            DataType.UBYTE -> RuntimeValueNumeric(type, (v shl 1) and 255)
-            DataType.UWORD -> RuntimeValueNumeric(type, (v shl 1) and 65535)
-            DataType.BYTE -> {
-                val value = v shl 1
-                if (value < 128)
-                    RuntimeValueNumeric(type, value)
-                else
-                    RuntimeValueNumeric(type, value - 256)
-            }
-            DataType.WORD -> {
-                val value = v shl 1
-                if (value < 32768)
-                    RuntimeValueNumeric(type, value)
-                else
-                    RuntimeValueNumeric(type, value - 65536)
-            }
-            else -> throw ArithmeticException("invalid type for shl: $type")
-        }
-    }
-
-    fun shr(): RuntimeValueNumeric {
-        val v = integerValue()
-        return when (type) {
-            DataType.UBYTE -> RuntimeValueNumeric(type, v ushr 1)
-            DataType.BYTE -> RuntimeValueNumeric(type, v shr 1)
-            DataType.UWORD -> RuntimeValueNumeric(type, v ushr 1)
-            DataType.WORD -> RuntimeValueNumeric(type, v shr 1)
-            else -> throw ArithmeticException("invalid type for shr: $type")
-        }
-    }
-
-    fun rol(carry: Boolean): Pair<RuntimeValueNumeric, Boolean> {
-        // 9 or 17 bit rotate left (with carry))
-        return when (type) {
-            DataType.UBYTE, DataType.BYTE -> {
-                val v = byteval!!.toInt()
-                val newCarry = (v and 0x80) != 0
-                val newval = (v and 0x7f shl 1) or (if (carry) 1 else 0)
-                Pair(RuntimeValueNumeric(DataType.UBYTE, newval), newCarry)
-            }
-            DataType.UWORD, DataType.WORD -> {
-                val v = wordval!!
-                val newCarry = (v and 0x8000) != 0
-                val newval = (v and 0x7fff shl 1) or (if (carry) 1 else 0)
-                Pair(RuntimeValueNumeric(DataType.UWORD, newval), newCarry)
-            }
-            else -> throw ArithmeticException("rol can only work on byte/word")
-        }
-    }
-
-    fun ror(carry: Boolean): Pair<RuntimeValueNumeric, Boolean> {
-        // 9 or 17 bit rotate right (with carry)
-        return when (type) {
-            DataType.UBYTE, DataType.BYTE -> {
-                val v = byteval!!.toInt()
-                val newCarry = v and 1 != 0
-                val newval = (v ushr 1) or (if (carry) 0x80 else 0)
-                Pair(RuntimeValueNumeric(DataType.UBYTE, newval), newCarry)
-            }
-            DataType.UWORD, DataType.WORD -> {
-                val v = wordval!!
-                val newCarry = v and 1 != 0
-                val newval = (v ushr 1) or (if (carry) 0x8000 else 0)
-                Pair(RuntimeValueNumeric(DataType.UWORD, newval), newCarry)
-            }
-            else -> throw ArithmeticException("ror2 can only work on byte/word")
-        }
-    }
-
-    fun rol2(): RuntimeValueNumeric {
-        // 8 or 16 bit rotate left
-        return when (type) {
-            DataType.UBYTE, DataType.BYTE -> {
-                val v = byteval!!.toInt()
-                val carry = (v and 0x80) ushr 7
-                val newval = (v and 0x7f shl 1) or carry
-                RuntimeValueNumeric(DataType.UBYTE, newval)
-            }
-            DataType.UWORD, DataType.WORD -> {
-                val v = wordval!!
-                val carry = (v and 0x8000) ushr 15
-                val newval = (v and 0x7fff shl 1) or carry
-                RuntimeValueNumeric(DataType.UWORD, newval)
-            }
-            else -> throw ArithmeticException("rol2 can only work on byte/word")
-        }
-    }
-
-    fun ror2(): RuntimeValueNumeric {
-        // 8 or 16 bit rotate right
-        return when (type) {
-            DataType.UBYTE, DataType.BYTE -> {
-                val v = byteval!!.toInt()
-                val carry = v and 1 shl 7
-                val newval = (v ushr 1) or carry
-                RuntimeValueNumeric(DataType.UBYTE, newval)
-            }
-            DataType.UWORD, DataType.WORD -> {
-                val v = wordval!!
-                val carry = v and 1 shl 15
-                val newval = (v ushr 1) or carry
-                RuntimeValueNumeric(DataType.UWORD, newval)
-            }
-            else -> throw ArithmeticException("ror2 can only work on byte/word")
-        }
-    }
-
-    fun neg(): RuntimeValueNumeric {
-        return when (type) {
-            DataType.BYTE -> RuntimeValueNumeric(DataType.BYTE, -(byteval!!))
-            DataType.WORD -> RuntimeValueNumeric(DataType.WORD, -(wordval!!))
-            DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, -(floatval)!!)
-            else -> throw ArithmeticException("neg can only work on byte/word/float")
-        }
-    }
-
-    fun abs(): RuntimeValueNumeric {
-        return when (type) {
-            DataType.BYTE -> RuntimeValueNumeric(DataType.BYTE, abs(byteval!!.toInt()))
-            DataType.WORD -> RuntimeValueNumeric(DataType.WORD, abs(wordval!!))
-            DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, abs(floatval!!))
-            else -> throw ArithmeticException("abs can only work on byte/word/float")
-        }
-    }
-
-    fun bitand(other: RuntimeValueNumeric): RuntimeValueNumeric {
-        val v1 = integerValue()
-        val v2 = other.integerValue()
-        val result = v1 and v2
-        return RuntimeValueNumeric(type, result)
-    }
-
-    fun bitor(other: RuntimeValueNumeric): RuntimeValueNumeric {
-        val v1 = integerValue()
-        val v2 = other.integerValue()
-        val result = v1 or v2
-        return RuntimeValueNumeric(type, result)
-    }
-
-    fun bitxor(other: RuntimeValueNumeric): RuntimeValueNumeric {
-        val v1 = integerValue()
-        val v2 = other.integerValue()
-        val result = v1 xor v2
-        return RuntimeValueNumeric(type, result)
-    }
-
-    fun and(other: RuntimeValueNumeric) = RuntimeValueNumeric(DataType.UBYTE, if (this.asBoolean && other.asBoolean) 1 else 0)
-    fun or(other: RuntimeValueNumeric) = RuntimeValueNumeric(DataType.UBYTE, if (this.asBoolean || other.asBoolean) 1 else 0)
-    fun xor(other: RuntimeValueNumeric) = RuntimeValueNumeric(DataType.UBYTE, if (this.asBoolean xor other.asBoolean) 1 else 0)
-    fun not() = RuntimeValueNumeric(DataType.UBYTE, if (this.asBoolean) 0 else 1)
-
-    fun inv(): RuntimeValueNumeric {
-        return when (type) {
-            DataType.UBYTE -> RuntimeValueNumeric(type, byteval!!.toInt().inv() and 255)
-            DataType.UWORD -> RuntimeValueNumeric(type, wordval!!.inv() and 65535)
-            DataType.BYTE -> RuntimeValueNumeric(type, byteval!!.toInt().inv())
-            DataType.WORD -> RuntimeValueNumeric(type, wordval!!.inv())
-            else -> throw ArithmeticException("inv can only work on byte/word")
-        }
-    }
-
-    fun inc(): RuntimeValueNumeric {
-        return when (type) {
-            DataType.UBYTE -> RuntimeValueNumeric(type, (byteval!! + 1) and 255)
-            DataType.UWORD -> RuntimeValueNumeric(type, (wordval!! + 1) and 65535)
-            DataType.BYTE -> {
-                val newval = byteval!! + 1
-                if (newval == 128)
-                    RuntimeValueNumeric(type, -128)
-                else
-                    RuntimeValueNumeric(type, newval)
-            }
-            DataType.WORD -> {
-                val newval = wordval!! + 1
-                if (newval == 32768)
-                    RuntimeValueNumeric(type, -32768)
-                else
-                    RuntimeValueNumeric(type, newval)
-            }
-            DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, floatval!! + 1)
-            else -> throw ArithmeticException("inc can only work on numeric types")
-        }
-    }
-
-    fun dec(): RuntimeValueNumeric {
-        return when (type) {
-            DataType.UBYTE -> RuntimeValueNumeric(type, (byteval!! - 1) and 255)
-            DataType.UWORD -> RuntimeValueNumeric(type, (wordval!! - 1) and 65535)
-            DataType.BYTE -> {
-                val newval = byteval!! - 1
-                if (newval == -129)
-                    RuntimeValueNumeric(type, 127)
-                else
-                    RuntimeValueNumeric(type, newval)
-            }
-            DataType.WORD -> {
-                val newval = wordval!! - 1
-                if (newval == -32769)
-                    RuntimeValueNumeric(type, 32767)
-                else
-                    RuntimeValueNumeric(type, newval)
-            }
-            DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, floatval!! - 1)
-            else -> throw ArithmeticException("dec can only work on numeric types")
-        }
-    }
-
-    fun msb(): RuntimeValueNumeric {
-        return when (type) {
-            in ByteDatatypes -> RuntimeValueNumeric(DataType.UBYTE, 0)
-            in WordDatatypes -> RuntimeValueNumeric(DataType.UBYTE, wordval!! ushr 8 and 255)
-            else -> throw ArithmeticException("msb can only work on (u)byte/(u)word")
-        }
-    }
-
-    fun cast(targetType: DataType): RuntimeValueNumeric {
-        return when (type) {
-            DataType.UBYTE -> {
-                when (targetType) {
-                    DataType.UBYTE -> this
-                    DataType.BYTE -> {
-                        val nval = byteval!!.toInt()
-                        if (nval < 128)
-                            RuntimeValueNumeric(DataType.BYTE, nval)
-                        else
-                            RuntimeValueNumeric(DataType.BYTE, nval - 256)
-                    }
-                    DataType.UWORD -> RuntimeValueNumeric(DataType.UWORD, numericValue())
-                    DataType.WORD -> {
-                        val nval = numericValue().toInt()
-                        if (nval < 32768)
-                            RuntimeValueNumeric(DataType.WORD, nval)
-                        else
-                            RuntimeValueNumeric(DataType.WORD, nval - 65536)
-                    }
-                    DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, numericValue())
-                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
-                }
-            }
-            DataType.BYTE -> {
-                when (targetType) {
-                    DataType.BYTE -> this
-                    DataType.UBYTE -> RuntimeValueNumeric(DataType.UBYTE, integerValue() and 255)
-                    DataType.UWORD -> RuntimeValueNumeric(DataType.UWORD, integerValue() and 65535)
-                    DataType.WORD -> RuntimeValueNumeric(DataType.WORD, integerValue())
-                    DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, numericValue())
-                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
-                }
-            }
-            DataType.UWORD -> {
-                when (targetType) {
-                    DataType.BYTE -> {
-                        val v = integerValue()
-                        if (v < 128)
-                            RuntimeValueNumeric(DataType.BYTE, v)
-                        else
-                            RuntimeValueNumeric(DataType.BYTE, v - 256)
-                    }
-                    DataType.UBYTE -> RuntimeValueNumeric(DataType.UBYTE, integerValue() and 255)
-                    DataType.UWORD -> this
-                    DataType.WORD -> {
-                        val v = integerValue()
-                        if (v < 32768)
-                            RuntimeValueNumeric(DataType.WORD, v)
-                        else
-                            RuntimeValueNumeric(DataType.WORD, v - 65536)
-                    }
-                    DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, numericValue())
-                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
-                }
-            }
-            DataType.WORD -> {
-                when (targetType) {
-                    DataType.BYTE -> {
-                        val v = integerValue() and 255
-                        if (v < 128)
-                            RuntimeValueNumeric(DataType.BYTE, v)
-                        else
-                            RuntimeValueNumeric(DataType.BYTE, v - 256)
-                    }
-                    DataType.UBYTE -> RuntimeValueNumeric(DataType.UBYTE, integerValue() and 65535)
-                    DataType.UWORD -> RuntimeValueNumeric(DataType.UWORD, integerValue())
-                    DataType.WORD -> this
-                    DataType.FLOAT -> RuntimeValueNumeric(DataType.FLOAT, numericValue())
-                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
-                }
-            }
-            DataType.FLOAT -> {
-                when (targetType) {
-                    DataType.BYTE -> {
-                        val integer = numericValue().toInt()
-                        if (integer in -128..127)
-                            RuntimeValueNumeric(DataType.BYTE, integer)
-                        else
-                            throw ArithmeticException("overflow when casting float to byte: $this")
-                    }
-                    DataType.UBYTE -> RuntimeValueNumeric(DataType.UBYTE, numericValue().toInt())
-                    DataType.UWORD -> RuntimeValueNumeric(DataType.UWORD, numericValue().toInt())
-                    DataType.WORD -> {
-                        val integer = numericValue().toInt()
-                        if (integer in -32768..32767)
-                            RuntimeValueNumeric(DataType.WORD, integer)
-                        else
-                            throw ArithmeticException("overflow when casting float to word: $this")
-                    }
-                    DataType.FLOAT -> this
-                    else -> throw ArithmeticException("invalid type cast from $type to $targetType")
-                }
-            }
-            else -> throw ArithmeticException("invalid type cast from $type to $targetType")
-        }
-    }
-}
-
-
-class RuntimeValueString(val str: String, val heapId: Int?): RuntimeValueBase(DataType.STR) {
-    companion object {
-        fun fromLv(string: StringLiteralValue): RuntimeValueString {
-            return RuntimeValueString(string.value, string.heapId)
-        }
-    }
-
-    override fun toString(): String = if(type==DataType.STR) "str:$str"  else "???"
-
-    override fun hashCode(): Int = Objects.hash(type, str)
-
-    override fun equals(other: Any?): Boolean {
-        if (other == null || other !is RuntimeValueString)
-            return false
-        return type == other.type && str == other.str
-    }
-
-    fun iterator(): Iterator<Number> = str.map { it.toShort() }.iterator()
-
-    override fun numericValue(): Number {
-        throw VmExecutionException("string is not a number")
-    }
-
-    override fun integerValue(): Int {
-        throw VmExecutionException("string is not a number")
-    }
-}
-
-
-open class RuntimeValueArray(type: DataType, val array: Array<Number>, val heapId: Int?): RuntimeValueBase(type) {
-
-    companion object {
-        fun fromLv(array: ArrayLiteralValue): RuntimeValueArray {
-            return if (array.type == DataType.ARRAY_F) {
-                val doubleArray = array.value.map { (it as NumericLiteralValue).number }.toTypedArray()
-                RuntimeValueArray(array.type, doubleArray, array.heapId)
-            } else {
-                val resultArray = mutableListOf<Number>()
-                for (elt in array.value.withIndex()) {
-                    if (elt.value is NumericLiteralValue)
-                        resultArray.add((elt.value as NumericLiteralValue).number.toInt())
-                    else {
-                        resultArray.add((elt.hashCode()))  // ...poor man's implementation of ADDRESSOF(array), it probably won't work very well
-                    }
-                }
-                RuntimeValueArray(array.type, resultArray.toTypedArray(), array.heapId)
-            }
-        }
-    }
-
-    override fun toString(): String {
-        return when (type) {
-            DataType.ARRAY_UB -> "array_ub:..."
-            DataType.ARRAY_B -> "array_b:..."
-            DataType.ARRAY_UW -> "array_uw:..."
-            DataType.ARRAY_W -> "array_w:..."
-            DataType.ARRAY_F -> "array_f:..."
-            else -> "???"
-        }
-    }
-
-    override fun hashCode(): Int = Objects.hash(type, array)
-
-    override fun equals(other: Any?): Boolean {
-        if (other == null || other !is RuntimeValueArray)
-            return false
-        return type == other.type && array.contentEquals(other.array)
-    }
-
-    open fun iterator(): Iterator<Number> = array.iterator()
-
-    override fun numericValue(): Number {
-        throw VmExecutionException("array is not a number")
-    }
-
-    override fun integerValue(): Int {
-        throw VmExecutionException("array is not a number")
-    }
-}
-
-
-class RuntimeValueRange(type: DataType, val range: IntProgression): RuntimeValueArray(type, range.toList().toTypedArray(), null) {
-    override fun iterator(): Iterator<Number> {
-        return range.iterator()
-    }
-}