optimize comparison to true/1 into comparison to zero, optimize while/until conditions

codeOptimizers/src/prog8/optimizer/ExpressionSimplifier.kt

@@ -249,6 +249,28 @@ class ExpressionSimplifier(private val program: Program) : AstWalker() {
             else -> null
         }
 
+        if(rightVal!=null && leftDt==DataType.BOOL) {
+            // see if we can replace comparison against true/1 with simpler comparison against zero
+            if (expr.operator == "==") {
+                if (rightVal.number == 1.0) {
+                    val zero = NumericLiteral(DataType.UBYTE, 0.0, expr.right.position)
+                    return listOf(
+                        IAstModification.SetExpression({expr.operator="!="}, expr, parent),
+                        IAstModification.ReplaceNode(expr.right, zero, expr)
+                    )
+                }
+            }
+            if (expr.operator == "!=") {
+                if (rightVal.number == 1.0) {
+                    val zero = NumericLiteral(DataType.UBYTE, 0.0, expr.right.position)
+                    return listOf(
+                        IAstModification.SetExpression({expr.operator="=="}, expr, parent),
+                        IAstModification.ReplaceNode(expr.right, zero, expr)
+                    )
+                }
+            }
+        }
+
         if(newExpr != null)
             return listOf(IAstModification.ReplaceNode(expr, newExpr, parent))
 

compiler/src/prog8/compiler/astprocessing/CodeDesugarer.kt

@@ -1,10 +1,7 @@
 package prog8.compiler.astprocessing
 
 import prog8.ast.*
-import prog8.ast.expressions.BinaryExpression
+import prog8.ast.expressions.*
-import prog8.ast.expressions.DirectMemoryRead
-import prog8.ast.expressions.FunctionCallExpression
-import prog8.ast.expressions.NumericLiteral
 import prog8.ast.statements.*
 import prog8.ast.walk.AstWalker
 import prog8.ast.walk.IAstModification
@@ -64,11 +61,12 @@ if CONDITION==0
          */
         val pos = untilLoop.position
         val loopLabel = program.makeLabel("untilloop", pos)
-        val equalsZero = BinaryExpression(untilLoop.condition, "==", NumericLiteral(DataType.UBYTE, 0.0, pos), pos)
+        val ifCondition = invertCondition(untilLoop.condition)
+            ?: BinaryExpression(untilLoop.condition, "==", NumericLiteral(DataType.UBYTE, 0.0, pos), pos)
         val replacement = AnonymousScope(mutableListOf(
             loopLabel,
             untilLoop.body,
-            IfElse(equalsZero,
+            IfElse(ifCondition,
                 AnonymousScope(mutableListOf(program.jumpLabel(loopLabel)), pos),
                 AnonymousScope(mutableListOf(), pos),
                 pos)
@@ -89,10 +87,11 @@ _after:
         val pos = whileLoop.position
         val loopLabel = program.makeLabel("whileloop", pos)
         val afterLabel = program.makeLabel("afterwhile", pos)
-        val equalsZero = BinaryExpression(whileLoop.condition, "==", NumericLiteral(DataType.UBYTE, 0.0, pos), pos)
+        val ifCondition = invertCondition(whileLoop.condition)
+            ?: BinaryExpression(whileLoop.condition, "==", NumericLiteral(DataType.UBYTE, 0.0, pos), pos)
         val replacement = AnonymousScope(mutableListOf(
             loopLabel,
-            IfElse(equalsZero,
+            IfElse(ifCondition,
                 AnonymousScope(mutableListOf(program.jumpLabel(afterLabel)), pos),
                 AnonymousScope(mutableListOf(), pos),
                 pos),

docs/source/todo.rst

@@ -3,10 +3,6 @@ TODO
 
 For next release
 ^^^^^^^^^^^^^^^^
-- petaxian has become larger (18630) why so much larger.   problematic lines:
-    gun.p8 95,110 if ( x <= GUN_MAX_LEFT and leftmost ) ...
-    enemy.p8 456 + bombs.p8 33 (while i<value)...
-
 - have a proper option to move the evalstack rather than just assembly symbol redefine
 - then make the cx16 virtual registers in syslib.p8 use that definition to be able to shift them around on non-cx16 targets
 

examples/test.p8

@@ -3,36 +3,14 @@
 
 
 main {
-  ubyte key
-
-  sub pushing_fire() -> ubyte {
-    return key == 'z'
-  }
-
-  sub pushing_left() -> ubyte {
-    return key == 'k' or key == 157
-  }
-
-  sub pushing_right() -> ubyte {
-    return key == 'l' or key == 29
-  }
-
     sub start() {
-        void pushing_fire()
+        bool @shared zz
-        void pushing_left()
+        ubyte xx
-        void pushing_right()
 
-        ubyte rnr = $99
+        while xx<42 {
-        ubyte wordNr = ((rnr >= $33) as ubyte) +
+            xx++
-            ((rnr >= $66) as ubyte) +
+        }
-            ((rnr >= $99) as ubyte) +
-            ((rnr >= $CC) as ubyte)
 
-        ubyte wordNr2 = (rnr >= $33) as ubyte + (rnr >= $66) as ubyte + (rnr >= $99) as ubyte + (rnr >= $CC) as ubyte
+        txt.print_ub(xx)
-
-        txt.print_uw(wordNr)
-        txt.nl()
-        txt.print_uw(wordNr2)
-        txt.nl()
     }
 }