todo

compiler/res/prog8lib/c64/graphics.p8

@@ -67,11 +67,14 @@ graphics {
             if positive_ix {
                 repeat {
                     internal_plot(y1)
-                    if internal_plotx==x2
+                    cmp(internal_plotx,x2)
-                        return
+                    if_eq return
+;                    if internal_plotx==x2
+;                        return
                     internal_plotx++
                     d += dy2
-                    if d > dx {
+                    cmp(d,dx)
+                    if_pl {
                         y1++
                         d -= dx2
                     }
@@ -79,11 +82,14 @@ graphics {
             } else {
                 repeat {
                     internal_plot(y1)
-                    if internal_plotx==x2
+                    cmp(internal_plotx,x2)
-                        return
+                    if_eq return
+;                    if internal_plotx==x2
+;                        return
                     internal_plotx--
                     d += dy2
-                    if d > dx {
+                    cmp(d,dx)
+                    if_pl {
                         y1++
                         d -= dx2
                     }
@@ -94,11 +100,14 @@ graphics {
             if positive_ix {
                 repeat {
                     internal_plot(y1)
-                    if y1 == y2
+                    cmp(y1,y2)
-                        return
+                    if_eq return
+;                    if y1 == y2
+;                        return
                     y1++
                     d += dx2
-                    if d > dy {
+                    cmp(d,dy)
+                    if_pl {
                         internal_plotx++
                         d -= dy2
                     }
@@ -106,11 +115,14 @@ graphics {
             } else {
                 repeat {
                     internal_plot(y1)
-                    if y1 == y2
+                    cmp(y1,y2)
-                        return
+                    if_eq return
+;                    if y1 == y2
+;                        return
                     y1++
                     d += dx2
-                    if d > dy {
+                    cmp(d,dy)
+                    if_pl {
                         internal_plotx--
                         d -= dy2
                     }

compiler/src/prog8/compiler/target/cpu6502/codegen/ExpressionsAsmGen.kt

@@ -32,8 +32,8 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
     }
 
     internal fun translateComparisonExpressionWithJumpIfFalse(expr: BinaryExpression, jumpIfFalseLabel: String) {
-        // first, if it is of the form:   <constvalue> <comparison> X  ,  swap the operands around,
+         // This is a helper routine called from while, do-util, and if expressions to generate optimized conditional branching code.
-        // so that the constant value is always the right operand.
+        // First, if it is of the form:   <constvalue> <comparison> X  ,  then flip the expression so the constant is always the right operand.
         var left = expr.left
         var right = expr.right
         var operator = expr.operator
@@ -396,6 +396,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize if right is variable or mem-read to avoid use of ZP location
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_B1", DataType.UBYTE, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.A)
         asmgen.out("  cmp  P8ZP_SCRATCH_B1 |  bcs  $jumpIfFalseLabel")
@@ -425,6 +426,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize if right is variable or mem-read to avoid use of ZP location
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_B1", DataType.UBYTE, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.A)
         asmgen.out("""
@@ -461,6 +463,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize this so it doesn't call a comparison-subroutine
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.AY)
         asmgen.out("  jsr  prog8_lib.reg_less_uw |  beq  $jumpIfFalseLabel")
@@ -491,6 +494,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize this so it doesn't call a comparison-subroutine
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.AY)
         asmgen.out("  jsr  prog8_lib.reg_less_w |  beq  $jumpIfFalseLabel")
@@ -526,6 +530,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize if right is variable or mem-read to avoid use of ZP location
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_B1", DataType.UBYTE, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.A)
         asmgen.out("""
@@ -560,6 +565,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize if right is variable or mem-read to avoid use of ZP location
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_B1", DataType.UBYTE, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.A)
         asmgen.out("""
@@ -602,6 +608,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize this so it doesn't call a comparison-subroutine
         asmgen.assignExpressionToVariable(left, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
         asmgen.assignExpressionToRegister(right, RegisterOrPair.AY)
         asmgen.out("  jsr  prog8_lib.reg_less_uw |  beq  $jumpIfFalseLabel")
@@ -638,6 +645,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize this so it doesn't call a comparison-subroutine
         asmgen.assignExpressionToVariable(left, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
         asmgen.assignExpressionToRegister(right, RegisterOrPair.AY)
         asmgen.out("  jsr  prog8_lib.reg_less_w |  beq  $jumpIfFalseLabel")
@@ -680,6 +688,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize if right is variable or mem-read to avoid use of ZP location
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_B1", DataType.UBYTE, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.A)
         asmgen.out("""
@@ -717,6 +726,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize if right is variable or mem-read to avoid use of ZP location
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_B1", DataType.UBYTE, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.A)
         asmgen.out("""
@@ -756,6 +766,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize this so it doesn't call a comparison-subroutine
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.AY)
         asmgen.out("  jsr  prog8_lib.reg_lesseq_uw |  beq  $jumpIfFalseLabel")
@@ -792,6 +803,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize this so it doesn't call a comparison-subroutine
         asmgen.assignExpressionToVariable(left, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
         asmgen.assignExpressionToRegister(right, RegisterOrPair.AY)
         asmgen.out("  jsr  prog8_lib.reg_lesseq_w |  beq  $jumpIfFalseLabel")
@@ -822,6 +834,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize if right is variable or mem-read to avoid use of ZP location
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_B1", DataType.UBYTE, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.A)
         asmgen.out("  cmp  P8ZP_SCRATCH_B1 |  bcc  $jumpIfFalseLabel")
@@ -854,6 +867,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize if right is variable or mem-read to avoid use of ZP location
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_B1", DataType.UBYTE, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.A)
         asmgen.out("""
@@ -888,6 +902,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize this so it doesn't call a comparison-subroutine
         asmgen.assignExpressionToVariable(left, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
         asmgen.assignExpressionToRegister(right, RegisterOrPair.AY)
         asmgen.out("  jsr  prog8_lib.reg_lesseq_uw |  beq  $jumpIfFalseLabel")
@@ -919,6 +934,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize this so it doesn't call a comparison-subroutine
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.AY)
         asmgen.out("  jsr  prog8_lib.reg_lesseq_w |  beq  $jumpIfFalseLabel")
@@ -950,6 +966,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize if right is variable or mem-read to avoid use of ZP location
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_B1", DataType.UBYTE, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.A)
         asmgen.out("  cmp  P8ZP_SCRATCH_B1 |  bne  $jumpIfFalseLabel")
@@ -981,6 +998,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize if right is variable or mem-read to avoid use of ZP location
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_B1", DataType.UBYTE, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.A)
         asmgen.out("  cmp  P8ZP_SCRATCH_B1 |  beq  $jumpIfFalseLabel")
@@ -1014,6 +1032,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize if right is variable or mem-read to avoid use of ZP location
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.AY)
         asmgen.out("""
@@ -1053,6 +1072,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             }
         }
 
+        // TODO optimize if right is variable or mem-read to avoid use of ZP location
         asmgen.assignExpressionToVariable(right, "P8ZP_SCRATCH_W2", DataType.UWORD, null)
         asmgen.assignExpressionToRegister(left, RegisterOrPair.AY)
         asmgen.out("""

docs/source/todo.rst

@@ -3,6 +3,8 @@ TODO
 ====
 
 - optimize comparisons followed by a conditional jump ; try to not have to jsr to the comparison routines. (so if/while/do-until are faster)
+   see: ExpressionAsmGen  translateXXXXXJump() routines, all called from translateComparisonExpressionWithJumpIfFalse()
+- add cx16 vload()
 
 - optimize several inner loops in gfx2
 - hoist all variable declarations up to the subroutine scope *before* even the constant folding takes place (to avoid undefined symbol errors when referring to a variable from another nested scope in the subroutine)

examples/test.p8

@@ -3,21 +3,12 @@
 
 main {
     sub start() {
-        byte xx
-        word yy
-
-        uword addr = $3000
-        cmp(xx, @($2000))
-        cmp(@($2000), xx)
-        cmp(yy, @($2000))
-        cmp(@($2000), yy)
-    }
-    sub start3() {
 
         byte xx
         byte yy
 
-        ; all comparisons with constant values are already optimized
+        ; all comparisons with constant values are already optimized.
+        ; but for variables (and memreads) we can optimize further (don't use temporary ZP location)
 
         byte value = 100