From 5e6e711f33f88d873333c2e7c7fedb91ca60f3ab Mon Sep 17 00:00:00 2001
From: Irmen de Jong <irmen@razorvine.net>
Date: Sun, 14 Feb 2021 00:05:57 +0100
Subject: [PATCH] optimize pokew()

---
 .../c64/codegen/BuiltinFunctionsAsmGen.kt     | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/compiler/src/prog8/compiler/target/c64/codegen/BuiltinFunctionsAsmGen.kt b/compiler/src/prog8/compiler/target/c64/codegen/BuiltinFunctionsAsmGen.kt
index 516aec86e..0e062d184 100644
--- a/compiler/src/prog8/compiler/target/c64/codegen/BuiltinFunctionsAsmGen.kt
+++ b/compiler/src/prog8/compiler/target/c64/codegen/BuiltinFunctionsAsmGen.kt
@@ -964,6 +964,55 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
     }
 
     private fun funcPokeW(fcall: IFunctionCall) {
+        when(val addrExpr = fcall.args[0]) {
+            is NumericLiteralValue -> {
+                asmgen.assignExpressionToRegister(fcall.args[1], RegisterOrPair.AY)
+                val addr = addrExpr.number.toHex()
+                asmgen.out("  sta  $addr |  sty  ${addr}+1")
+                return
+            }
+            is IdentifierReference -> {
+                val varname = asmgen.asmVariableName(addrExpr)
+                if(asmgen.isZpVar(addrExpr)) {
+                    // pointervar is already in the zero page, no need to copy
+                    asmgen.saveRegisterLocal(CpuRegister.X, (fcall as Node).definingSubroutine()!!)
+                    asmgen.assignExpressionToRegister(fcall.args[1], RegisterOrPair.AX)
+                    if (asmgen.compTarget.machine.cpu == CpuType.CPU65c02) {
+                        asmgen.out("""
+                            sta  ($varname)
+                            txa
+                            ldy  #1
+                            sta  ($varname),y""")
+                    } else {
+                        asmgen.out("""
+                            ldy  #0
+                            sta  ($varname),y
+                            txa
+                            iny
+                            sta  ($varname),y""")
+                    }
+                    asmgen.restoreRegisterLocal(CpuRegister.X)
+                    return
+                }
+            }
+            is BinaryExpression -> {
+                if(addrExpr.operator=="+" && addrExpr.left is IdentifierReference && addrExpr.right is NumericLiteralValue) {
+                    asmgen.saveRegisterLocal(CpuRegister.X, (fcall as Node).definingSubroutine()!!)
+                    asmgen.assignExpressionToRegister(fcall.args[1], RegisterOrPair.AX)
+                    val varname = asmgen.asmVariableName(addrExpr.left as IdentifierReference)
+                    val index = (addrExpr.right as NumericLiteralValue).number.toHex()
+                    asmgen.out("""
+                        ldy  #$index
+                        sta  ($varname),y
+                        txa
+                        iny
+                        sta  ($varname),y""")
+                    asmgen.restoreRegisterLocal(CpuRegister.X)
+                    return
+                }
+            }
+        }
+
         asmgen.assignExpressionToVariable(fcall.args[0], "P8ZP_SCRATCH_W1", DataType.UWORD, null)
         asmgen.assignExpressionToRegister(fcall.args[1], RegisterOrPair.AY)
         asmgen.out("  jsr  prog8_lib.func_pokew")