weird condition operator...

codeCore/src/prog8/code/SymbolTable.kt

@@ -33,9 +33,9 @@ class SymbolTable(astProgram: PtProgram) : StNode(astProgram.name, StNodeType.GL
         return result
     }
 
-//    fun resetCachedFlat() {
+    fun resetCachedFlat() {
-//        cachedFlat = null
+        cachedFlat = null
-//    }
+    }
 
     val allVariables: Collection<StStaticVariable> by lazy {
         val vars = mutableListOf<StStaticVariable>()

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

@@ -1174,30 +1174,29 @@ $repeatLabel    lda  $counterVar
 
     private fun translateCompareAndJumpIfTrueRPN(expr: PtRpn, jump: PtJump) {
         val (left, oper, right) = expr.finalOperation()
-        if(expr.children.size>3) {
-            TODO("RPN comparison too complex ${expr.position}")
-        }
-
-        require(left is PtExpression && right is PtExpression)
-
         if(oper.operator !in ComparisonOperators)
             throw AssemblyError("must be comparison expression")
+        if(expr.children.size>3) {
+            TODO("RPN comparison too complex ${expr.position} - split off the comparison + compare value")
+        }
 
         // invert the comparison, so we can reuse the JumpIfFalse code generation routines
         val invertedComparisonOperator = invertedComparisonOperator(oper.operator)
             ?: throw AssemblyError("can't invert comparison $expr")
 
-        val rightConstVal = right as? PtNumber
-
         val label = when {
             jump.generatedLabel!=null -> jump.generatedLabel!!
             jump.identifier!=null -> asmSymbolName(jump.identifier!!)
             jump.address!=null -> jump.address!!.toHex()
             else -> throw AssemblyError("weird jump")
         }
-        if (rightConstVal!=null && rightConstVal.number == 0.0)
+        val rightConstVal = right as? PtNumber
+        if (rightConstVal!=null && rightConstVal.number == 0.0) {
+            require(left is PtExpression)
             testZeroAndJump(left, invertedComparisonOperator, label)
+        }
         else {
+            require(left is PtExpression && right is PtExpression)
             val leftConstVal = left as? PtNumber
             testNonzeroComparisonAndJump(left, invertedComparisonOperator, right, label, leftConstVal, rightConstVal)
         }
@@ -1206,7 +1205,7 @@ $repeatLabel    lda  $counterVar
     private fun translateCompareAndJumpIfFalseRPN(expr: PtRpn, jumpIfFalseLabel: String) {
         val (left, oper, right) = expr.finalOperation()
         if(expr.children.size>3) {
-            TODO("RPN comparison too complex ${expr.position}")
+            TODO("RPN comparison too complex ${expr.position} - split off the comparison + compare value")
         }
 
         require(left is PtExpression && right is PtExpression)

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

@@ -365,7 +365,9 @@ internal class AssignmentAsmGen(private val program: PtProgram,
     private fun attemptAssignOptimizedExprRPN(assign: AsmAssignment, scope: IPtSubroutine): Boolean {
         val value = assign.source.expression as PtRpn
         val (left, oper, right) = value.finalOperation()
-        if(oper.operator in ComparisonOperators) {
+
+        // TODO RPN the fallthrough if size>3 seems to generate not 100% correct code... (balls example fills the screen weird)
+        if(value.children.size==3 && oper.operator in ComparisonOperators) {
             assignRPNComparison(assign, value)
             return true
         }
@@ -424,19 +426,18 @@ internal class AssignmentAsmGen(private val program: PtProgram,
         value.children.forEach {
             when (it) {
                 is PtRpnOperator -> {
-                    val varDt = getVarDt(it.type)
+                    val rightvar = evalVars.getValue(getVarDt(it.rightType)).pop()
-                    val rightvar = evalVars.getValue(varDt).pop()
+                    val leftvar = evalVars.getValue(getVarDt(it.leftType)).pop()
-                    val leftvar = evalVars.getValue(varDt).pop()
                     depth-=2
                     val resultVarname = evalVarName(it.type, depth)
                     depth++
                     require(resultVarname==leftvar)
-                    // TODO no longer needed? symbolTable.resetCachedFlat()
+                    symbolTable.resetCachedFlat()
                     if(it.operator in ComparisonOperators) {
                         val scopeName = (scope as PtNamedNode).scopedName
                         val comparison = PtRpn(DataType.UBYTE, assign.position)
                         comparison.addRpnNode(PtIdentifier("$scopeName.$resultVarname", it.type, value.position))
-                        comparison.addRpnNode(PtIdentifier("$scopeName.$rightvar", it.type, value.position))
+                        comparison.addRpnNode(PtIdentifier("$scopeName.$rightvar", it.rightType, value.position))
                         comparison.addRpnNode(PtRpnOperator(it.operator, it.type, it.leftType, it.rightType, it.position))
                         comparison.parent = scope
                         val src = AsmAssignSource(SourceStorageKind.EXPRESSION, program, asmgen, DataType.UBYTE, expression = comparison)
@@ -577,7 +578,6 @@ internal class AssignmentAsmGen(private val program: PtProgram,
             else -> throw AssemblyError("invalid dt")
         }
         asmgen.out(jumpIfFalseLabel)
-        asmgen.out("; cmp done")
     }
 
     private fun attemptAssignOptimizedBinexpr(expr: PtBinaryExpression, assign: AsmAssignment): Boolean {

docs/source/todo.rst

@@ -1,10 +1,12 @@
 TODO
 ====
 
+BRANCH: balls.p8  directions are wrong since the comparison operator fallthrough in attemptAssignOptimizedExprRPN
 BRANCH: Fix the TODO RPN routines to be optimized assembly in RpnExpressionAsmGen.kt
 BRANCH: check BinExprSplitter disablement any effect for RPN?
 BRANCH: Implement RPN codegen for IR.
 
+
 For next minor release
 ^^^^^^^^^^^^^^^^^^^^^^
 ...

examples/test.p8

@@ -6,12 +6,15 @@
 main {
 
     sub start() {
-        ubyte[255] BC
+;        ubyte[255] BC
-        bool[255] DX
+;        bool[255] DX
 
-        BC[2] = math.rnd() & 15
+        if math.rnd() & 22 {
-        BC[3] = math.rnd() & 15
+            cx16.r0L++
-        BC[4] = math.rnd() & 15
+        }
+;        BC[2] = math.rnd() & 15
+;        BC[3] = math.rnd() & 15
+;        BC[4] = math.rnd() & 15
         ;DX[2] = math.rnd() & 1
     }
 }