From bcedb5f5e3c339a0bbbc8472807fa9bb392cc93e Mon Sep 17 00:00:00 2001
From: Irmen de Jong <irmen@razorvine.net>
Date: Wed, 17 Oct 2018 18:11:36 +0200
Subject: [PATCH] fix some asm

---
 compiler/examples/test.p8                     |  2 +-
 .../src/prog8/compiler/target/c64/AsmGen.kt   | 83 +++++++++++++++----
 2 files changed, 68 insertions(+), 17 deletions(-)

diff --git a/compiler/examples/test.p8 b/compiler/examples/test.p8
index bde920a8f..59a8a8f8c 100644
--- a/compiler/examples/test.p8
+++ b/compiler/examples/test.p8
@@ -20,7 +20,7 @@ sub start() {
 
     A++
     X++
-    ;AY++
+    AY++
 
     A = ~X
     A = not Y
diff --git a/compiler/src/prog8/compiler/target/c64/AsmGen.kt b/compiler/src/prog8/compiler/target/c64/AsmGen.kt
index 1fc60c31b..34fdc2d6e 100644
--- a/compiler/src/prog8/compiler/target/c64/AsmGen.kt
+++ b/compiler/src/prog8/compiler/target/c64/AsmGen.kt
@@ -311,6 +311,10 @@ class AsmGen(val options: CompilationOptions, val program: IntermediateProgram,
         out("\tdex")
     }
 
+    private fun replaceByteA() {
+        out("\tsta  ${(ESTACK_LO+1).toHex()},x")
+    }
+
     private fun pushMemByte(address: Int) {
         out("\tlda  ${address.toHex()}")
         out("\tsta  ${ESTACK_LO.toHex()},x")
@@ -338,6 +342,12 @@ class AsmGen(val options: CompilationOptions, val program: IntermediateProgram,
         out("\tdex")
     }
 
+    private fun replaceWordAY() {
+        out("\tsta  ${(ESTACK_LO+1).toHex()},x")
+        out("\ttya")
+        out("\tsta  ${(ESTACK_HI+1).toHex()},x")
+    }
+
     private fun pushMemWord(address: Int) {
         out("\tlda  ${address.toHex()}")
         out("\tsta  ${ESTACK_LO.toHex()},x")
@@ -373,16 +383,40 @@ class AsmGen(val options: CompilationOptions, val program: IntermediateProgram,
     }
 
     private fun popByteA() {
+        // for operations that remove a value from the stack
         out("\tinx")
         out("\tlda  ${ESTACK_LO.toHex()},x")
     }
 
+    private fun peekByteA() {
+        // for operations that modify a value on the stack
+        out("\tlda  ${(ESTACK_LO+1).toHex()},x")
+    }
+
+    private fun peekByte2A() {
+        // for operations that modify a value on the stack, 1 under the top
+        out("\tlda  ${(ESTACK_LO+2).toHex()},x")
+    }
+
     private fun popWordAY() {
+        // for operations that remove a value from the stack
         out("\ninx")
         out("\tlda  ${ESTACK_LO.toHex()},x")
         out("\tldy  ${ESTACK_HI.toHex()},x")
     }
 
+    private fun peekWordAY() {
+        // for operations that modify a value on the stack
+        out("\tlda  ${(ESTACK_LO+1).toHex()},x")
+        out("\tldy  ${(ESTACK_HI+1).toHex()},x")
+    }
+
+    private fun peekWord2AY() {
+        // for operations that modify a value on the stack, 1 under the top
+        out("\tlda  ${(ESTACK_LO+2).toHex()},x")
+        out("\tldy  ${(ESTACK_HI+2).toHex()},x")
+    }
+
     private fun instr2asm(insIdx: Int, ins: Instruction, block: IntermediateProgram.ProgramBlock): Int {
         if(ins is LabelInstr) {
             if(ins.name==block.shortname)
@@ -676,16 +710,16 @@ class AsmGen(val options: CompilationOptions, val program: IntermediateProgram,
                 out("\tdec  ${ins.callLabel}")
             }
             Opcode.ADD_UB, Opcode.ADD_B -> {
-                out("\tlda  ${(ESTACK_LO+2).toHex()},x")
+                peekByte2A()
                 out("\tclc\n\tadc  ${(ESTACK_LO+1).toHex()},x")
-                out("\tsta  ${(ESTACK_LO+2).toHex()},x")
                 out("\tinx")
+                replaceByteA()
             }
             Opcode.SUB_UB, Opcode.SUB_B -> {
-                out("\tlda  ${(ESTACK_LO+2).toHex()},x")
+                peekByte2A()
                 out("\tsec\n\tsbc  ${(ESTACK_LO+1).toHex()},x")
-                out("\tsta  ${(ESTACK_LO+2).toHex()},x")
                 out("\tinx")
+                replaceByteA()
             }
             Opcode.POP_MEM_UB, Opcode.POP_MEM_B -> {
                 popByteA()
@@ -703,25 +737,42 @@ class AsmGen(val options: CompilationOptions, val program: IntermediateProgram,
                 out("\tsty  ${ins.callLabel}+1")
             }
             Opcode.NEG_B -> {
-                popByteA()
+                peekByteA()
                 out("\teor  #\$ff")
                 out("\tsec\n\tadc  #0")
-                pushByteA()
+                replaceByteA()
             }
-            Opcode.INV_BYTE, Opcode.NOT_BYTE -> {
-                popByteA()
+            Opcode.INV_BYTE -> {
+                peekByteA()
                 out("\teor  #\$ff")
-                pushByteA()
+                replaceByteA()
             }
-            Opcode.INV_WORD, Opcode.NOT_WORD -> {
-                popWordAY()
+            Opcode.INV_WORD -> {
+                out("\tlda  ${(ESTACK_LO+1).toHex()},x")
                 out("\teor  #\$ff")
-                out("\tpha")
-                out("\ttya")
+                out("\tlda  ${(ESTACK_HI+1).toHex()},x")
                 out("\teor  #\$ff")
-                out("\ttay")
-                out("\tpla")
-                pushWordAY()
+                out("\tsta  ${(ESTACK_LO+1).toHex()},x")
+                out("\tsta  ${(ESTACK_HI+1).toHex()},x")
+            }
+            Opcode.NOT_BYTE -> {
+                peekByteA()
+                out("\tbeq  +")
+                out("\tlda  #0")
+                out("\tbeq  ++")
+                out("+\tlda  #1")
+                out("++")
+                replaceByteA()
+            }
+            Opcode.NOT_WORD -> {
+                out("\tlda  ${(ESTACK_LO+1).toHex()},x")
+                out("\tora  ${(ESTACK_HI+1).toHex()},x")
+                out("\tbeq  +")
+                out("\tlda  #0")
+                out("\tbeq  ++")
+                out("+\tlda  #1")
+                out("++\tsta  ${(ESTACK_LO+1).toHex()},x")
+                out("\tsta  ${(ESTACK_HI+1).toHex()},x")
             }
 
             else-> TODO("asm for $ins")