From cf6ea63fa66aea05411da84f802883770487a520 Mon Sep 17 00:00:00 2001
From: Irmen de Jong <irmen@razorvine.net>
Date: Tue, 18 Aug 2020 15:29:39 +0200
Subject: [PATCH] forloop asm done

---
 compiler/src/prog8/compiler/Zeropage.kt       |  2 +-
 .../compiler/target/c64/codegen/AsmGen.kt     |  6 ++--
 .../target/c64/codegen/ForLoopsAsmGen.kt      | 28 +++++++++++++------
 3 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/compiler/src/prog8/compiler/Zeropage.kt b/compiler/src/prog8/compiler/Zeropage.kt
index f0a53bece..4eaa0ed9c 100644
--- a/compiler/src/prog8/compiler/Zeropage.kt
+++ b/compiler/src/prog8/compiler/Zeropage.kt
@@ -16,7 +16,7 @@ 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?, errors: ErrorReporter): Int {
-        assert(scopedname.isEmpty() || !allocations.values.any { it.first==scopedname } ) {"isSameAs scopedname can't be allocated twice"}
+        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")
diff --git a/compiler/src/prog8/compiler/target/c64/codegen/AsmGen.kt b/compiler/src/prog8/compiler/target/c64/codegen/AsmGen.kt
index d117e9801..76104e9fb 100644
--- a/compiler/src/prog8/compiler/target/c64/codegen/AsmGen.kt
+++ b/compiler/src/prog8/compiler/target/c64/codegen/AsmGen.kt
@@ -27,9 +27,9 @@ import kotlin.math.absoluteValue
 
 
 internal class AsmGen(private val program: Program,
-                      private val errors: ErrorReporter,
-                      private val zeropage: Zeropage,
-                      private val options: CompilationOptions,
+                      val errors: ErrorReporter,
+                      val zeropage: Zeropage,
+                      val options: CompilationOptions,
                       private val outputDir: Path): IAssemblyGenerator {
 
     private val assemblyLines = mutableListOf<String>()
diff --git a/compiler/src/prog8/compiler/target/c64/codegen/ForLoopsAsmGen.kt b/compiler/src/prog8/compiler/target/c64/codegen/ForLoopsAsmGen.kt
index 31f7dbd2c..eb15dc09c 100644
--- a/compiler/src/prog8/compiler/target/c64/codegen/ForLoopsAsmGen.kt
+++ b/compiler/src/prog8/compiler/target/c64/codegen/ForLoopsAsmGen.kt
@@ -291,7 +291,7 @@ $endLabel""")
             }
             DataType.ARRAY_UB, DataType.ARRAY_B -> {
                 val length = decl.arraysize!!.size()!!
-                val indexVar = asmgen.makeLabel("for_index")      // TODO allocate dynamically, zero page preferred if length >= 16
+                val indexVar = asmgen.makeLabel("for_index")
                 asmgen.out("""
                     ldy  #0
 $loopLabel          sty  $indexVar
@@ -313,13 +313,19 @@ $loopLabel          sty  $indexVar
                         bne  $loopLabel
                         beq  $endLabel""")
                 }
-                asmgen.out("""
-$indexVar           .byte  0
-$endLabel""")
+                if(length>=16 && asmgen.zeropage.available() > 0) {
+                    // allocate index var on ZP if possible
+                    val zpAddr = asmgen.zeropage.allocate(indexVar, DataType.UBYTE, stmt.position, asmgen.errors)
+                    asmgen.out("""$indexVar = $zpAddr  ; auto zp UBYTE""")
+                } else {
+                    asmgen.out("""
+$indexVar           .byte  0""")
+                }
+                asmgen.out(endLabel)
             }
             DataType.ARRAY_W, DataType.ARRAY_UW -> {
                 val length = decl.arraysize!!.size()!! * 2
-                val indexVar = asmgen.makeLabel("for_index")    // todo allocate dynamically, zero page preferred if length >= 16
+                val indexVar = asmgen.makeLabel("for_index")
                 val loopvarName = asmgen.asmIdentifierName(stmt.loopVar)
                 asmgen.out("""
                     ldy  #0
@@ -346,9 +352,15 @@ $loopLabel          sty  $indexVar
                         bne  $loopLabel
                         beq  $endLabel""")
                 }
-                asmgen.out("""
-$indexVar           .byte  0
-$endLabel""")
+                if(length>=16 && asmgen.zeropage.available() > 0) {
+                    // allocate index var on ZP if possible
+                    val zpAddr = asmgen.zeropage.allocate(indexVar, DataType.UBYTE, stmt.position, asmgen.errors)
+                    asmgen.out("""$indexVar = $zpAddr  ; auto zp UBYTE""")
+                } else {
+                    asmgen.out("""
+$indexVar           .byte  0""")
+                }
+                asmgen.out(endLabel)
             }
             DataType.ARRAY_F -> {
                 throw AssemblyError("for loop with floating point variables is not supported")