optimize cmp word equal/notequal

codeGenCpu6502/src/prog8/codegen/cpu6502/AsmGen.kt

@@ -2456,11 +2456,9 @@ $repeatLabel    lda  $counterVar
                     assignExpressionToRegister(right, RegisterOrPair.AY)
                 } else {
                     pushCpuStack(DataType.UWORD, left)
-                    assignExpressionToRegister(right, RegisterOrPair.AY)
+                    assignExpressionToVariable(right, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
-                    out("  sta  P8ZP_SCRATCH_REG")
+                    restoreRegisterStack(CpuRegister.Y, false)
-                    popCpuStack(DataType.UWORD, "P8ZP_SCRATCH_W2")
+                    restoreRegisterStack(CpuRegister.A, false)
-                    out("  lda  P8ZP_SCRATCH_REG")
-                    // TODO optimize this path..... CMP_OPT
                 }
                 out("""
                     cmp  P8ZP_SCRATCH_W2
@@ -2544,11 +2542,9 @@ $repeatLabel    lda  $counterVar
                     assignExpressionToRegister(right, RegisterOrPair.AY)
                 } else {
                     pushCpuStack(DataType.UWORD, left)
-                    assignExpressionToRegister(right, RegisterOrPair.AY)
+                    assignExpressionToVariable(right, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
-                    out("  sta  P8ZP_SCRATCH_REG")
+                    restoreRegisterStack(CpuRegister.Y, false)
-                    popCpuStack(DataType.UWORD, "P8ZP_SCRATCH_W2")
+                    restoreRegisterStack(CpuRegister.A, false)
-                    out("  lda  P8ZP_SCRATCH_REG")
-                    // TODO optimize this path..... CMP_OPT
                 }
                 out("""
                     cmp  P8ZP_SCRATCH_W2

docs/source/todo.rst

@@ -3,8 +3,6 @@ TODO
 
 For next release
 ^^^^^^^^^^^^^^^^
-- optimize cmp's that can use the variable directly  out("  cmp  $.....
-- optimize cmp word equal/notequal search for CMP_OPT
 - 6502 codegen: make it possible to use cpu opcodes such as 'nop' as variable names by prefixing all asm vars with something such as ``p8v_``? Or not worth it (most 3 letter opcodes as variables are nonsensical anyway)
   then we can get rid of the instruction lists in the machinedefinitions as well.  This is already no problem at all in the IR codegen.
 - create BSS section in output program and put StStaticVariables in there with bss=true. Don't forget to add init code to zero out everything that was put in bss. If array in bss->only zero ONCE! So requires self-modifying code

examples/test.p8

@@ -1,11 +1,17 @@
 %import textio
 %zeropage dontuse
 
+
+; base level code size: $279
+
+
 main {
   bool[1] expected = [ true ]
   uword[1] expectedw = [4242 ]
 
   sub get() -> bool {
+    ubyte xx
+    xx = 1
     %asm {{
         stz  P8ZP_SCRATCH_W1
         stz  P8ZP_SCRATCH_W1+1
@@ -14,9 +20,11 @@ main {
         stz  P8ZP_SCRATCH_REG
         stz  P8ZP_SCRATCH_B1
     }}
-    return true
+    return xx
   }
   sub same() -> bool {
+    ubyte xx
+    xx = 1
     %asm {{
         stz  P8ZP_SCRATCH_W1
         stz  P8ZP_SCRATCH_W1+1
@@ -25,10 +33,11 @@ main {
         stz  P8ZP_SCRATCH_REG
         stz  P8ZP_SCRATCH_B1
     }}
-    return true
+    return xx
   }
 
   sub getw() -> uword {
+    uword xx=4242
     %asm {{
         stz  P8ZP_SCRATCH_W1
         stz  P8ZP_SCRATCH_W1+1
@@ -37,9 +46,10 @@ main {
         stz  P8ZP_SCRATCH_REG
         stz  P8ZP_SCRATCH_B1
     }}
-    return 4242
+    return xx
   }
   sub samew() -> uword {
+    uword xx=4242
     %asm {{
         stz  P8ZP_SCRATCH_W1
         stz  P8ZP_SCRATCH_W1+1
@@ -48,9 +58,22 @@ main {
         stz  P8ZP_SCRATCH_REG
         stz  P8ZP_SCRATCH_B1
     }}
-    return 4242
+    return xx
+  }
+  sub differentw() -> uword {
+    uword xx=9999
+    %asm {{
+        stz  P8ZP_SCRATCH_W1
+        stz  P8ZP_SCRATCH_W1+1
+        stz  P8ZP_SCRATCH_W2
+        stz  P8ZP_SCRATCH_W2+1
+        stz  P8ZP_SCRATCH_REG
+        stz  P8ZP_SCRATCH_B1
+    }}
+    return xx
   }
   sub one() -> ubyte {
+    ubyte xx=1
     %asm {{
         stz  P8ZP_SCRATCH_W1
         stz  P8ZP_SCRATCH_W1+1
@@ -59,110 +82,50 @@ main {
         stz  P8ZP_SCRATCH_REG
         stz  P8ZP_SCRATCH_B1
     }}
-    return 1
+    return xx
   }
 
   sub start() {
-    if get() == expected[0]
-      txt.print("ok\n")
-    else
-      txt.print("fail\n")
-
-    ; this is working fine:
-    if expected[0] == get()
-      txt.print("ok\n")
-    else
-      txt.print("fail\n")
-
-    if getw() == expectedw[0]
-      txt.print("ok\n")
-    else
-      txt.print("fail\n")
-
-    ; this is working fine:
-    if expectedw[0] == getw()
-      txt.print("ok\n")
-    else
-      txt.print("fail\n")
-
-    ; unquals
-
-    if get() != expected[0]
-      txt.print("fail\n")
-    else
-      txt.print("ok\n")
-
-    ; this is working fine:
-    if expected[0] != get()
-      txt.print("fail\n")
-    else
-      txt.print("ok\n")
-
-    if getw() != expectedw[0]
-      txt.print("fail\n")
-    else
-      txt.print("ok\n")
-
-    ; this is working fine:
-    if expectedw[0] != getw()
-      txt.print("fail\n")
-    else
-      txt.print("ok\n")
-
-    ;  now with 2 non-simple operands:
-    if get() == same()
-      txt.print("ok\n")
-    else
-      txt.print("fail\n")
-
-    ; this is working fine:
-    if same() == get()
-      txt.print("ok\n")
-    else
-      txt.print("fail\n")
-
     if getw() == samew()
       txt.print("ok\n")
     else
       txt.print("fail\n")
 
-    ; this is working fine:
     if samew() == getw()
       txt.print("ok\n")
     else
       txt.print("fail\n")
 
-    ; unquals
-
-    if get() != same()
-      txt.print("fail\n")
-    else
-      txt.print("ok\n")
-
-    ; this is working fine:
-    if same() != get()
-      txt.print("fail\n")
-    else
-      txt.print("ok\n")
-
     if getw() != samew()
       txt.print("fail\n")
     else
       txt.print("ok\n")
 
-    ; this is working fine:
     if samew() != getw()
       txt.print("fail\n")
     else
       txt.print("ok\n")
 
 
-     ; pointer stuff
+    if getw() == differentw()
-     uword ptr = $4000
+      txt.print("fail\n")
-     @(ptr+one()) = 42
+    else
-     if @(ptr+one()) == 42
+      txt.print("ok\n")
-        txt.print("ok\n")
+
-     else
+    if differentw() == getw()
-        txt.print("fail\n")
+      txt.print("fail\n")
+    else
+      txt.print("ok\n")
+
+    if getw() != differentw()
+      txt.print("ok\n")
+    else
+      txt.print("fail\n")
+
+    if differentw() != getw()
+      txt.print("ok\n")
+    else
+      txt.print("fail\n")
+
   }
 }