vm: support noreinit option

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

@@ -27,8 +27,10 @@ internal class AssemblyProgram(override val name: String,
             }
             out.write("------PROGRAM------\n")
 
+            if(!options.dontReinitGlobals) {
                 out.write("; global var inits\n")
                 globalInits.forEach { out.writeLine(it) }
+            }
 
             out.write("; actual program code\n")
             blocks.asSequence().flatMap { it.lines }.forEach { line->out.writeLine(line) }

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

@@ -35,20 +35,17 @@ class CodeGen(internal val program: PtProgram,
     private val builtinFuncGen = BuiltinFuncGen(this, expressionEval)
     internal val vmRegisters = VmRegisterPool()
 
-    init {
-        if(options.dontReinitGlobals)
-            TODO("support no globals re-init in vm")
-    }
-
     override fun compileToAssembly(): IAssemblyProgram? {
         val vmprog = AssemblyProgram(program.name, allocations)
 
+        if(!options.dontReinitGlobals) {
             // collect global variables initializers
             program.allBlocks().forEach {
                 val code = VmCodeChunk()
                 it.children.filterIsInstance<PtAssignment>().forEach { assign -> code += translate(assign) }
                 vmprog.addGlobalInits(code)
             }
+        }
 
         for (block in program.allBlocks()) {
             vmprog.addBlock(translate(block))

docs/source/todo.rst

@@ -3,10 +3,10 @@ TODO
 
 For next release
 ^^^^^^^^^^^^^^^^
-- vm: support no globals re-init option
-- vm: make registers typed? so that it's immediately obvious what type they represent. Much like regular variables in memory.
-- vm: don't store symbol names in instructions to make optimizing the IR easier? but what about jumps to labels. And it's no longer readable by humans.
 - vm codegen/assembler: variable memory locations should also be referenced by the variable name instead of just the address, to make the output more human-readable
+- vm: make registers typed? so that it's immediately obvious what type they represent. Much like regular variables in memory.
+  so we have a set of byte registers, a set of word registers, and other sets if we introduce other types.
+- vm: don't store symbol names in instructions to make optimizing the IR easier? but what about jumps to labels. And it's no longer readable by humans.
 - vm: how to remove all unused subroutines? (in the assembly codegen, we let 64tass solve this for us)
 - vm: rather than being able to jump to any 'address' (IPTR), use 'blocks' that have entry and exit points -> even better dead code elimination possible too
 - when the vm is stable and *if* its language can get promoted to prog8 IL, the variable allocation should be changed.

examples/test.p8

@@ -1,34 +1,16 @@
 %import textio
-%zeropage basicsafe
+%zeropage dontuse
+
 
 ; NOTE: meant to test to virtual machine output target (use -target vitual)
 
 main {
 
-    sub func1(ubyte arg1) -> uword {
-        return arg1 * 3
-    }
-
-    sub func2(uword arg1) -> uword {
-        return arg1+1000
-    }
-
-    sub func3(uword arg1) {
-        txt.print_uw(arg1+2000)
-        txt.nl()
-    }
+    ubyte global = 42
 
     sub start() {
-
-        ubyte source = 99
-
-        uword result = func2(func1(cos8u(sin8u(source))))
-        txt.print_uw(result)    ; 1043
-        txt.nl()
-        result = source |> sin8u() |> cos8u() |> func1() |> func2()
-        txt.print_uw(result)    ; 1043
-        txt.nl()
-        source |> sin8u() |> cos8u() |> func1() |> func3()      ; 2043
+        txt.print_ub(global)
+        global++
 
         ; a "pixelshader":
 ;        syscall1(8, 0)      ; enable lo res creen