optimized word comparison expressions

codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/AssignmentAsmGen.kt

@@ -820,7 +820,7 @@ internal class AssignmentAsmGen(private val program: PtProgram,
     }
 
     private fun assignOptimizedComparisonWords(expr: PtBinaryExpression, assign: AsmAssignment): Boolean {
-        val signed = expr.left.type == DataType.BYTE || expr.right.type ==  DataType.BYTE
+        val signed = expr.left.type == DataType.WORD || expr.right.type ==  DataType.WORD
         fun assignExpressionOperandsLeftScratchRightAY() {
             if(expr.right.isSimple()) {
                 assignExpressionToVariable(expr.left, "P8ZP_SCRATCH_W1", expr.left.type)
@@ -834,6 +834,19 @@ internal class AssignmentAsmGen(private val program: PtProgram,
                 asmgen.restoreRegisterStack(CpuRegister.A, false)
             }
         }
+        fun assignExpressionOperandsLeftAYRightScratch() {
+            if(expr.left.isSimple()) {
+                assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_W1", expr.left.type)
+                assignExpressionToRegister(expr.left, RegisterOrPair.AY, signed)
+            } else {
+                assignExpressionToRegister(expr.left, RegisterOrPair.AY, signed)
+                asmgen.saveRegisterStack(CpuRegister.A, false)
+                asmgen.saveRegisterStack(CpuRegister.Y, false)
+                assignExpressionToVariable(expr.right, "P8ZP_SCRATCH_W1", expr.left.type)
+                asmgen.restoreRegisterStack(CpuRegister.Y, false)
+                asmgen.restoreRegisterStack(CpuRegister.A, false)
+            }
+        }
         when(expr.operator) {
             "==" -> {
                 assignExpressionOperandsLeftScratchRightAY()
@@ -861,42 +874,118 @@ internal class AssignmentAsmGen(private val program: PtProgram,
             }
             "<" -> {
                 if(signed) {
-                    // TODO("word <")
+                    assignExpressionOperandsLeftAYRightScratch()
-                    return false
+                    asmgen.out("""
+		cmp  P8ZP_SCRATCH_W1
+        tya
+		sbc  P8ZP_SCRATCH_W1+1
+		bvc  +
+		eor  #${'$'}80
++		bpl  ++
++       lda  #1
+        bne  ++
++       lda  #0
++""")
                 }
                 else {
-                    // TODO("uword <")
+                    assignExpressionOperandsLeftAYRightScratch()
-                    return false
+                    asmgen.out("""
+		cpy  P8ZP_SCRATCH_W1+1
+		bcc  +
+        bne  ++
+		cmp  P8ZP_SCRATCH_W1
+		bcs  ++
++       lda  #1
+        bne  ++
++       lda  #0
++""")
                 }
             }
             "<=" -> {
                 if(signed) {
-                    // TODO("word <=")
+                    assignExpressionOperandsLeftScratchRightAY()
-                    return false
+                    asmgen.out("""
+		cmp  P8ZP_SCRATCH_W1
+        tya
+		sbc  P8ZP_SCRATCH_W1+1
+		bvc  +
+		eor  #${'$'}80
++		bmi  +
+        lda  #1
+        bne  ++
++       lda  #0
++""")
                 }
                 else {
-                    // TODO("uword =<")
+                    assignExpressionOperandsLeftScratchRightAY()
-                    return false
+                    asmgen.out("""
+		cpy  P8ZP_SCRATCH_W1+1
+		bcc  ++
+		bne  +
+		cmp  P8ZP_SCRATCH_W1
+		bcc  ++                        
++       lda  #1
+        bne  ++
++       lda  #0
++""")
                 }
             }
             ">" -> {
                 if(signed) {
-                    // TODO("word >")
+                    assignExpressionOperandsLeftScratchRightAY()
-                    return false
+                    asmgen.out("""
+		cmp  P8ZP_SCRATCH_W1
+        tya
+		sbc  P8ZP_SCRATCH_W1+1
+		bvc  +
+		eor  #${'$'}80
++		bpl  ++
++       lda  #1
+        bne  ++
++       lda  #0
++""")
                 }
                 else {
-                    // TODO("uword >")
+                    assignExpressionOperandsLeftScratchRightAY()
-                    return false
+                    asmgen.out("""
+		cpy  P8ZP_SCRATCH_W1+1
+		bcc  +
+        bne  ++
+		cmp  P8ZP_SCRATCH_W1
+		bcs  ++
++       lda  #1
+        bne  ++
++       lda  #0
++""")
                 }
             }
             ">=" -> {
                 if(signed) {
-                    // TODO("word >=")
+                    assignExpressionOperandsLeftAYRightScratch()
-                    return false
+                    asmgen.out("""
+		cmp  P8ZP_SCRATCH_W1
+        tya
+		sbc  P8ZP_SCRATCH_W1+1
+		bvc  +
+		eor  #${'$'}80
++		bmi  +
+        lda  #1
+        bne  ++
++       lda  #0
++""")
                 }
                 else {
-                    // TODO("uword >=")
+                    assignExpressionOperandsLeftAYRightScratch()
-                    return false
+                    asmgen.out("""
+		cpy  P8ZP_SCRATCH_W1+1
+		bcc  ++
+		bne  +
+		cmp  P8ZP_SCRATCH_W1
+		bcc  ++                        
++       lda  #1
+        bne  ++
++       lda  #0
++""")
                 }
             }
             else -> return false

docs/source/todo.rst

@@ -3,8 +3,7 @@ TODO
 
 For next minor release
 ^^^^^^^^^^^^^^^^^^^^^^
-- finish assignOptimizedComparisonWords()
+- find bcc/bcs + lda branches that could be a rol?
-- find bcc/bcs branches that could be a rol?
 - find adc #0  that could be a rol?
 - try to optimize newexpr a bit more
 

examples/test.p8

@@ -6,50 +6,54 @@ main {
     sub start() {
         ubyte[10] envelope_attacks = 99
 
-
+        ; signed word:
-        ; signed and unsigned word:
         ; >
-        ; >=
-        ; <
-        ; <=
 
 
-        ; expect nope nope yep yep yep
+        ; expect yep nope nope nope yep nope
-        cx16.r0 = $ea30
+        cx16.r0s = -1000
-        cx16.r2 = $ea31
+        cx16.r2s = -999
-        if (cx16.r0 > cx16.r2) or (envelope_attacks[cx16.r1L]==0) {
+        if (cx16.r0s < cx16.r2s) or (envelope_attacks[cx16.r1L]==0) {
             txt.print("\nyep\n")
         } else {
             txt.print("\nnope\n")
         }
 
-        cx16.r0 = $ea31
+        cx16.r0s = -999
-        cx16.r2 = $ea31
+        cx16.r2s = -999
-        if (cx16.r0 > cx16.r2) or (envelope_attacks[cx16.r1L]==0) {
+        if (cx16.r0s < cx16.r2s) or (envelope_attacks[cx16.r1L]==0) {
             txt.print("\nyep\n")
         } else {
             txt.print("\nnope\n")
         }
 
-        cx16.r0 = $ea32
+        cx16.r0s = -998
-        cx16.r2 = $ea31
+        cx16.r2s = -999
-        if (cx16.r0 > cx16.r2) or (envelope_attacks[cx16.r1L]==0) {
+        if (cx16.r0s < cx16.r2s) or (envelope_attacks[cx16.r1L]==0) {
             txt.print("\nyep\n")
         } else {
             txt.print("\nnope\n")
         }
 
-        cx16.r0 = $ee30
+        cx16.r0s = 0
-        cx16.r2 = $ea31
+        cx16.r2s = -999
-        if (cx16.r0 > cx16.r2) or (envelope_attacks[cx16.r1L]==0) {
+        if (cx16.r0s < cx16.r2s) or (envelope_attacks[cx16.r1L]==0) {
             txt.print("\nyep\n")
         } else {
             txt.print("\nnope\n")
         }
 
-        cx16.r0 = $ffff
+        cx16.r0s = -999
-        cx16.r2 = $ee31
+        cx16.r2s = 0
-        if (cx16.r0 > cx16.r2) or (envelope_attacks[cx16.r1L]==0) {
+        if (cx16.r0s < cx16.r2s) or (envelope_attacks[cx16.r1L]==0) {
+            txt.print("\nyep\n")
+        } else {
+            txt.print("\nnope\n")
+        }
+
+        cx16.r0s = $7fff
+        cx16.r2s = $7eff
+        if (cx16.r0s < cx16.r2s) or (envelope_attacks[cx16.r1L]==0) {
             txt.print("\nyep\n")
         } else {
             txt.print("\nnope\n")