subroutine parameters can be allocated on the zp now as well

compiler/src/prog8/ast/statements/AstStatements.kt

@@ -270,7 +270,7 @@ open class VarDecl(val type: VarDeclType,
 
 // a vardecl used only for subroutine parameters
 class ParameterVarDecl(name: String, declaredDatatype: DataType, position: Position)
-    : VarDecl(VarDeclType.VAR, declaredDatatype, ZeropageWish.NOT_IN_ZEROPAGE, null, name, null, null, false, true, position)
+    : VarDecl(VarDeclType.VAR, declaredDatatype, ZeropageWish.DONTCARE, null, name, null, null, false, true, position)
 
 
 class ArrayIndex(var index: Expression, override val position: Position) : Node {

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

@@ -247,7 +247,6 @@ internal class AsmGen(private val program: Program,
         out("; vars allocated on zeropage")
         val variables = statements.filterIsInstance<VarDecl>().filter { it.type==VarDeclType.VAR }
         for(variable in variables) {
-            // should NOT allocate subroutine parameters on the zero page
             val fullName = variable.makeScopedName(variable.name)
             val zpVar = allocatedZeropageVariables[fullName]
             if(zpVar==null) {

docs/source/todo.rst

@@ -2,7 +2,6 @@
 TODO
 ====
 
-- allocate sub params in zeropage as well (it already allows @zp tag on them!)
 - optimize assignment codegeneration
 - get rid of all TODO's ;-)
 - make it possible to use cpu opcodes such as 'nop' as variable names by prefixing all asm vars with something such as '_'

examples/plasma.p8

@@ -71,10 +71,9 @@ main {
         }
         c2A += 2
         c2B -= 3
-        uword @zp scrptr = screen
         for y in 24 downto 0 {
             for x in 39 downto 0 {
-                @(scrptr) = xbuf[x] + ybuf[y]
+                @(screen) = xbuf[x] + ybuf[y]
 ;                %asm {{
 ;                     ldy  x
 ;                     lda  xbuf,y
@@ -82,9 +81,9 @@ main {
 ;                     clc
 ;                     adc  ybuf,y
 ;                     ldy  #0
-;                     sta  (scrptr),y
+;                     sta  (screen),y
 ;                 }}
-                scrptr++
+                screen++
              }
         }
     }

examples/test.p8

@@ -4,9 +4,12 @@
 main {
 
     sub start() {
-        uword addr=$d020
-        ubyte q =2
-        @(addr) += q
+
+        subje(12345)
+    }
+
+    sub subje(uword xx) {
+        @($c000) = lsb(xx)
     }
 }