From 41afeccd51859f640010b547595bad4fd2784027 Mon Sep 17 00:00:00 2001
From: Irmen de Jong <irmen@razorvine.net>
Date: Mon, 5 Feb 2024 01:09:33 +0100
Subject: [PATCH] compiler stuff

---
 .../src/prog8/codegen/cpu6502/Extensions.kt   |   4 +-
 .../codegen/cpu6502/VariableAllocator.kt      |   2 +-
 compiler/src/prog8/CompilerMain.kt            |   2 +
 compiler/src/prog8/compiler/Compiler.kt       |   4 +-
 .../compiler/astprocessing/AstChecker.kt      | 145 ++++++++----------
 .../compiler/astprocessing/AstExtensions.kt   |   4 -
 .../compiler/astprocessing/AstPreprocessor.kt |   2 +-
 .../astprocessing/BeforeAsmAstChanger.kt      |  27 +---
 .../astprocessing/BeforeAsmTypecastCleaner.kt |   8 -
 .../compiler/astprocessing/BoolRemover.kt     | 133 ----------------
 .../compiler/astprocessing/CodeDesugarer.kt   |   5 +
 .../astprocessing/IntermediateAstMaker.kt     |  21 +--
 .../astprocessing/LiteralsToAutoVars.kt       |   4 +-
 ...NotExpressionAndIfComparisonExprChanger.kt | 106 ++++++++-----
 .../astprocessing/StatementReorderer.kt       |   2 +-
 .../compiler/astprocessing/TypecastsAdder.kt  |  51 ++----
 .../astprocessing/VerifyFunctionArgTypes.kt   |   7 +-
 .../src/prog8/intermediate/IRFileReader.kt    |   9 +-
 .../src/prog8/intermediate/IRFileWriter.kt    |   5 +-
 .../src/prog8/intermediate/IRProgram.kt       |   4 +-
 .../src/prog8/intermediate/IRSymbolTable.kt   |  26 +++-
 intermediate/src/prog8/intermediate/Utils.kt  |   6 +-
 22 files changed, 220 insertions(+), 357 deletions(-)
 delete mode 100644 compiler/src/prog8/compiler/astprocessing/BoolRemover.kt

diff --git a/codeGenCpu6502/src/prog8/codegen/cpu6502/Extensions.kt b/codeGenCpu6502/src/prog8/codegen/cpu6502/Extensions.kt
index 3c2d5ed68..e6ac38b26 100644
--- a/codeGenCpu6502/src/prog8/codegen/cpu6502/Extensions.kt
+++ b/codeGenCpu6502/src/prog8/codegen/cpu6502/Extensions.kt
@@ -17,7 +17,7 @@ internal fun IPtSubroutine.returnsWhatWhere(): List<Pair<RegisterOrStatusflag, D
                 emptyList()
             else {
                 val register = when (returntype!!) {
-                    in ByteDatatypes -> RegisterOrStatusflag(RegisterOrPair.A, null)
+                    in ByteDatatypesWithBoolean -> RegisterOrStatusflag(RegisterOrPair.A, null)
                     in WordDatatypes -> RegisterOrStatusflag(RegisterOrPair.AY, null)
                     DataType.FLOAT -> RegisterOrStatusflag(RegisterOrPair.FAC1, null)
                     else -> RegisterOrStatusflag(RegisterOrPair.AY, null)
@@ -31,7 +31,7 @@ internal fun IPtSubroutine.returnsWhatWhere(): List<Pair<RegisterOrStatusflag, D
 
 internal fun PtSub.returnRegister(): RegisterOrStatusflag? {
     return when(returntype) {
-        in ByteDatatypes -> RegisterOrStatusflag(RegisterOrPair.A, null)
+        in ByteDatatypesWithBoolean -> RegisterOrStatusflag(RegisterOrPair.A, null)
         in WordDatatypes -> RegisterOrStatusflag(RegisterOrPair.AY, null)
         DataType.FLOAT -> RegisterOrStatusflag(RegisterOrPair.FAC1, null)
         null -> null
diff --git a/codeGenCpu6502/src/prog8/codegen/cpu6502/VariableAllocator.kt b/codeGenCpu6502/src/prog8/codegen/cpu6502/VariableAllocator.kt
index 86d335a68..53b02b4fe 100644
--- a/codeGenCpu6502/src/prog8/codegen/cpu6502/VariableAllocator.kt
+++ b/codeGenCpu6502/src/prog8/codegen/cpu6502/VariableAllocator.kt
@@ -91,7 +91,7 @@ internal class VariableAllocator(private val symboltable: SymbolTable,
             if(errors.noErrors()) {
                 val sortedList = varsDontCare.sortedByDescending { it.scopedName }
                 for (variable in sortedList) {
-                    if(variable.dt in IntegerDatatypes) {
+                    if(variable.dt in IntegerDatatypesWithBoolean) {
                         if(zeropage.free.isEmpty()) {
                             break
                         } else {
diff --git a/compiler/src/prog8/CompilerMain.kt b/compiler/src/prog8/CompilerMain.kt
index 0bdbbf32c..08340f4dc 100644
--- a/compiler/src/prog8/CompilerMain.kt
+++ b/compiler/src/prog8/CompilerMain.kt
@@ -70,6 +70,8 @@ private fun compileMain(args: Array<String>): Boolean {
         return false
     }
 
+    println("BREAKPOINTINSTR=$breakpointCpuInstruction")
+
     val outputPath = pathFrom(outputDir)
     if(!outputPath.toFile().isDirectory) {
         System.err.println("Output path doesn't exist")
diff --git a/compiler/src/prog8/compiler/Compiler.kt b/compiler/src/prog8/compiler/Compiler.kt
index f07e1d555..a54f89397 100644
--- a/compiler/src/prog8/compiler/Compiler.kt
+++ b/compiler/src/prog8/compiler/Compiler.kt
@@ -98,8 +98,8 @@ fun compileProgram(args: CompilerArguments): CompilationResult? {
             importedFiles = imported
 
             processAst(program, args.errors, compilationOptions)
-//                println("*********** COMPILER AST RIGHT BEFORE OPTIMIZING *************")
-//                printProgram(program)
+//            println("*********** COMPILER AST RIGHT BEFORE OPTIMIZING *************")
+//            printProgram(program)
 
             if (compilationOptions.optimize) {
                 optimizeAst(
diff --git a/compiler/src/prog8/compiler/astprocessing/AstChecker.kt b/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
index 94d82674a..aa73e97fd 100644
--- a/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
+++ b/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
@@ -123,12 +123,6 @@ internal class AstChecker(private val program: Program,
                     if(valueDt istype DataType.BOOL && expectedReturnValues[0] == DataType.UBYTE) {
                         // if the return value is a bool and the return type is ubyte, allow this. But give a warning.
                         errors.info("return type of the subroutine should probably be bool instead of ubyte", returnStmt.position)
-                    } else if(valueDt istype DataType.UBYTE && expectedReturnValues[0] == DataType.BOOL) {
-                        // if the return value is ubyte and the return type is bool, allow this only if value is 0 or 1
-                        val returnValue = returnStmt.value as? NumericLiteral
-                        if (returnValue == null || returnValue.type != DataType.UBYTE || (returnValue.number!=0.0 && returnValue.number!=1.0)) {
-                            errors.err("type $valueDt of return value doesn't match subroutine's return type ${expectedReturnValues[0]}",returnStmt.value!!.position)
-                        }
                     } else if(valueDt.isIterable && expectedReturnValues[0]==DataType.UWORD) {
                         // you can return a string or array when an uword (pointer) is returned
                     } else if(valueDt istype DataType.UWORD && expectedReturnValues[0]==DataType.STR) {
@@ -156,12 +150,9 @@ internal class AstChecker(private val program: Program,
     }
 
     override fun visit(ifElse: IfElse) {
-        val dt = ifElse.condition.inferType(program)
-        if(!dt.isInteger && !dt.istype(DataType.BOOL)) {
-            val identifier = ifElse.condition as? IdentifierReference
-            if(identifier==null || identifier.targetStatement(program)!=null)
-                errors.err("condition value should be an integer type or bool", ifElse.condition.position)
-        }
+        if(!ifElse.condition.inferType(program).isBool)
+            errors.err("condition should be a boolean", ifElse.condition.position)
+
         super.visit(ifElse)
     }
 
@@ -480,22 +471,16 @@ internal class AstChecker(private val program: Program,
     }
 
     override fun visit(untilLoop: UntilLoop) {
-        val dt = untilLoop.condition.inferType(program)
-        if(!dt.isInteger && !dt.istype(DataType.BOOL)) {
-            val identifier = untilLoop.condition as? IdentifierReference
-            if(identifier==null || identifier.targetStatement(program)!=null)
-                errors.err("condition value should be an integer type or bool", untilLoop.condition.position)
-        }
+        if(!untilLoop.condition.inferType(program).isBool)
+            errors.err("condition should be a boolean", untilLoop.condition.position)
+
         super.visit(untilLoop)
     }
 
     override fun visit(whileLoop: WhileLoop) {
-        val dt = whileLoop.condition.inferType(program)
-        if(!dt.isInteger && !dt.istype(DataType.BOOL)) {
-            val identifier = whileLoop.condition as? IdentifierReference
-            if(identifier==null || identifier.targetStatement(program)!=null)
-                errors.err("condition value should be an integer type or bool", whileLoop.condition.position)
-        }
+        if(!whileLoop.condition.inferType(program).isBool)
+            errors.err("condition should be a boolean", whileLoop.condition.position)
+
         super.visit(whileLoop)
     }
 
@@ -539,20 +524,10 @@ internal class AstChecker(private val program: Program,
         if(numvalue!=null && targetDt.isKnown)
             checkValueTypeAndRange(targetDt.getOr(DataType.UNDEFINED), numvalue)
 
-// for now, don't enforce bool type with only logical operators...
-//        if(assignment.isAugmentable && targetDt istype DataType.BOOL) {
-//            val operator = (assignment.value as? BinaryExpression)?.operator
-//            if(operator in InvalidOperatorsForBoolean)
-//                errors.err("can't use boolean operand with this operator $operator", assignment.position)
-//        }
-
         super.visit(assignment)
     }
 
     override fun visit(assignTarget: AssignTarget) {
-        if(assignTarget.inferType(program).istype(DataType.LONG))
-            errors.err("integer overflow", assignTarget.position)
-
         super.visit(assignTarget)
 
         val memAddr = assignTarget.memoryAddress?.addressExpression?.constValue(program)?.number?.toInt()
@@ -586,16 +561,13 @@ internal class AstChecker(private val program: Program,
         if (assignment is Assignment) {
             val targetDatatype = assignTarget.inferType(program)
             if (targetDatatype.isKnown) {
-                val constVal = assignment.value.constValue(program)
-                if(constVal==null) {
-                    val sourceDatatype = assignment.value.inferType(program)
-                    if (sourceDatatype.isUnknown) {
-                        if (assignment.value !is FunctionCallExpression)
-                            errors.err("invalid assignment value, maybe forgot '&' (address-of)", assignment.value.position)
-                    } else {
-                        checkAssignmentCompatible(targetDatatype.getOr(DataType.UNDEFINED),
-                                sourceDatatype.getOr(DataType.UNDEFINED), assignment.value)
-                    }
+                val sourceDatatype = assignment.value.inferType(program)
+                if (sourceDatatype.isUnknown) {
+                    if (assignment.value !is BinaryExpression && assignment.value !is PrefixExpression && assignment.value !is ContainmentCheck)
+                        errors.err("invalid assignment value, maybe forgot '&' (address-of)", assignment.value.position)
+                } else {
+                    checkAssignmentCompatible(targetDatatype.getOr(DataType.UNDEFINED),
+                            sourceDatatype.getOr(DataType.UNDEFINED), assignment.value)
                 }
             }
         }
@@ -619,6 +591,10 @@ internal class AstChecker(private val program: Program,
 
         if(decl.datatype==DataType.LONG)
             errors.err("integer overflow", decl.position)
+        if(decl.type==VarDeclType.MEMORY) {
+            if (decl.datatype == DataType.BOOL || decl.datatype == DataType.ARRAY_BOOL)
+                errors.err("variables mapped in memory should be numeric", decl.position)
+        }
 
         fun err(msg: String) = errors.err(msg, decl.position)
 
@@ -628,8 +604,8 @@ internal class AstChecker(private val program: Program,
 
         // CONST can only occur on simple types (byte, word, float)
         if(decl.type== VarDeclType.CONST) {
-            if (decl.datatype !in NumericDatatypes)
-                err("const can only be used on numeric types (byte, word, float)")
+            if (decl.datatype !in NumericDatatypesWithBoolean)
+                err("const can only be used on numeric types or booleans")
         }
 
         // FLOATS enabled?
@@ -717,11 +693,11 @@ internal class AstChecker(private val program: Program,
                     val eltDt = ArrayToElementTypes.getValue(decl.datatype)
                     if(iDt isnot eltDt) {
                         if(!(iDt.isBool && eltDt==DataType.UBYTE || iDt.istype(DataType.UBYTE) && eltDt==DataType.BOOL))
-                            err("initialisation value has incompatible type (${declValue.inferType(program)}) for the variable (${decl.datatype})")
+                            err("initialisation value has incompatible type ($iDt) for the variable (${decl.datatype})")
                     }
                 } else {
                     if(!(iDt.isBool && decl.datatype==DataType.UBYTE || iDt.istype(DataType.UBYTE) && decl.datatype==DataType.BOOL))
-                        err("initialisation value has incompatible type (${declValue.inferType(program)}) for the variable (${decl.datatype})")
+                        err("initialisation value has incompatible type ($iDt) for the variable (${decl.datatype})")
                 }
             }
         }
@@ -971,9 +947,13 @@ internal class AstChecker(private val program: Program,
         else if(expr.operator == "~") {
             if(dt !in IntegerDatatypes)
                 errors.err("can only use bitwise invert on integer types", expr.position)
-            if(dt==DataType.BOOL)
+            else if(dt==DataType.BOOL)
                 errors.err("bitwise invert is for integer types, use 'not' on booleans", expr.position)
         }
+        else if(expr.operator == "not") {
+            if(dt!=DataType.BOOL)
+                errors.err("logical not is for booleans", expr.position)
+        }
         super.visit(expr)
     }
 
@@ -1014,11 +994,6 @@ internal class AstChecker(private val program: Program,
                         errors.err("remainder can only be used on unsigned integer operands", expr.right.position)
                 }
             }
-            "&", "|", "^" -> {
-                // only integer numeric operands accepted
-                if(leftDt !in IntegerDatatypes || rightDt !in IntegerDatatypes)
-                    errors.err("bitwise operator can only be used on integer operands", expr.right.position)
-            }
             "in" -> throw FatalAstException("in expression should have been replaced by containmentcheck")
             "<<", ">>" -> {
                 if(rightDt in WordDatatypes) {
@@ -1043,10 +1018,12 @@ internal class AstChecker(private val program: Program,
                 // expression with one side BOOL other side (U)BYTE is allowed; bool==byte
             } else if((expr.operator == "<<" || expr.operator == ">>") && (leftDt in WordDatatypes && rightDt in ByteDatatypes)) {
                 // exception allowed: shifting a word by a byte
+            } else if((expr.operator in BitwiseOperators) && (leftDt in IntegerDatatypes && rightDt in IntegerDatatypes)) {
+                // exception allowed: bitwise operations with any integers
             } else if((leftDt==DataType.UWORD && rightDt==DataType.STR) || (leftDt==DataType.STR && rightDt==DataType.UWORD)) {
                 // exception allowed: comparing uword (pointer) with string
             } else {
-                errors.err("left and right operands aren't the same type", expr.left.position)
+                errors.err("left and right operands aren't the same type", expr.position)
             }
         }
 
@@ -1089,6 +1066,18 @@ internal class AstChecker(private val program: Program,
                 errors.err("can't use boolean operand with this operator ${expr.operator}", expr.right.position)
             }
         }
+
+
+        if(expr.operator in LogicalOperators) {
+            if (leftDt != DataType.BOOL || rightDt != DataType.BOOL)
+                errors.err("logical operator requires boolean operands", expr.right.position)
+        }
+        else {
+            if (leftDt == DataType.BOOL || rightDt == DataType.BOOL) {
+                if(expr.operator!="==" && expr.operator!="!=")
+                    errors.err("operator requires numeric operands", expr.right.position)
+            }
+        }
     }
 
     override fun visit(typecast: TypecastExpression) {
@@ -1289,14 +1278,7 @@ internal class AstChecker(private val program: Program,
         if(target is Label && args.isNotEmpty())
             errors.err("cannot use arguments when calling a label", position)
 
-        if(target is BuiltinFunctionPlaceholder) {
-            if(target.name=="all" || target.name=="any") {
-                if((args[0] as? AddressOf)?.identifier?.targetVarDecl(program)?.datatype == DataType.STR
-                    || args[0].inferType(program).getOr(DataType.STR) == DataType.STR) {
-                    errors.err("any/all on a string is useless (is always true unless the string is empty)", position)
-                }
-            }
-        } else if(target is Subroutine) {
+        if(target is Subroutine) {
             if(target.isAsmSubroutine) {
                 for (arg in args.zip(target.parameters)) {
                     val argIDt = arg.first.inferType(program)
@@ -1375,7 +1357,10 @@ internal class AstChecker(private val program: Program,
     }
 
     override fun visit(whenStmt: When) {
-        if(!whenStmt.condition.inferType(program).isInteger)
+        val conditionDt = whenStmt.condition.inferType(program)
+        if(conditionDt.isBool)
+            errors.err("condition is boolean, use if statement instead", whenStmt.position)
+        else if(!conditionDt.isInteger)
             errors.err("when condition must be an integer value", whenStmt.position)
         val tally = mutableSetOf<Int>()
         for((choices, choiceNode) in whenStmt.choiceValues(program)) {
@@ -1406,7 +1391,7 @@ internal class AstChecker(private val program: Program,
             for((constvalue, pos) in constvalues) {
                 when {
                     constvalue == null -> errors.err("choice value must be a constant", pos)
-                    constvalue.type !in IntegerDatatypes -> errors.err("choice value must be a byte or word", pos)
+                    constvalue.type !in IntegerDatatypesWithBoolean -> errors.err("choice value must be a byte or word", pos)
                     conditionType isnot constvalue.type -> {
                         if(conditionType.isKnown) {
                             if(conditionType.istype(DataType.BOOL)) {
@@ -1492,7 +1477,8 @@ internal class AstChecker(private val program: Program,
 
     private fun checkLongType(expression: Expression) {
         if(expression.inferType(program).istype(DataType.LONG)) {
-            errors.err("integer overflow", expression.position)
+            if(errors.noErrorForLine(expression.position))
+                errors.err("integer overflow", expression.position)
         }
     }
 
@@ -1654,13 +1640,14 @@ internal class AstChecker(private val program: Program,
                     return err("value '$number' out of range for word")
             }
             DataType.BOOL -> {
-                return true
+                if(value.type!=DataType.BOOL)
+                    err("type of value ${value.type} doesn't match target $targetDt")
             }
             in ArrayDatatypes -> {
                 val eltDt = ArrayToElementTypes.getValue(targetDt)
                 return checkValueTypeAndRange(eltDt, value)
             }
-            else -> return err("value of type ${value.type} not compatible with $targetDt")
+            else -> return err("type of value ${value.type} doesn't match target $targetDt")
         }
         return true
     }
@@ -1723,11 +1710,11 @@ internal class AstChecker(private val program: Program,
         }
 
         val result =  when(targetDatatype) {
-            DataType.BOOL -> sourceDatatype in NumericDatatypes
-            DataType.BYTE -> sourceDatatype == DataType.BYTE || sourceDatatype == DataType.BOOL
-            DataType.UBYTE -> sourceDatatype == DataType.UBYTE || sourceDatatype == DataType.BOOL
-            DataType.WORD -> sourceDatatype in setOf(DataType.BYTE, DataType.UBYTE, DataType.WORD, DataType.BOOL)
-            DataType.UWORD -> sourceDatatype == DataType.UBYTE || sourceDatatype == DataType.UWORD || sourceDatatype == DataType.BOOL
+            DataType.BOOL -> sourceDatatype==DataType.BOOL
+            DataType.BYTE -> sourceDatatype == DataType.BYTE
+            DataType.UBYTE -> sourceDatatype == DataType.UBYTE
+            DataType.WORD -> sourceDatatype in setOf(DataType.BYTE, DataType.UBYTE, DataType.WORD)
+            DataType.UWORD -> sourceDatatype == DataType.UBYTE || sourceDatatype == DataType.UWORD
             DataType.FLOAT -> sourceDatatype in NumericDatatypes
             DataType.STR -> sourceDatatype == DataType.STR
             else -> {
@@ -1747,12 +1734,14 @@ internal class AstChecker(private val program: Program,
         }
         else if(sourceDatatype== DataType.FLOAT && targetDatatype in IntegerDatatypes)
             errors.err("cannot assign float to ${targetDatatype.name.lowercase()}; possible loss of precision. Suggestion: round the value or revert to integer arithmetic", position)
+        else if((sourceValue as? BinaryExpression)?.operator in BitwiseOperators && targetDatatype.equalsSize(sourceDatatype)) {
+            // this is allowed: bitwise operation between different types as long as they're the same size.
+        }
+        else if(targetDatatype==DataType.UWORD && sourceDatatype in PassByReferenceDatatypes) {
+            // this is allowed: a pass-by-reference datatype into a uword (pointer value).
+        }
         else {
-            if(targetDatatype!=DataType.UWORD && sourceDatatype !in PassByReferenceDatatypes) {
-                // allow bitwise operations on different types as long as the size is the same
-                if (!((sourceValue as? BinaryExpression)?.operator in BitwiseOperators && targetDatatype.equalsSize(sourceDatatype)))
-                    errors.err("type of value $sourceDatatype doesn't match target $targetDatatype", position)
-            }
+            errors.err("type of value $sourceDatatype doesn't match target $targetDatatype", position)
         }
 
         return false
diff --git a/compiler/src/prog8/compiler/astprocessing/AstExtensions.kt b/compiler/src/prog8/compiler/astprocessing/AstExtensions.kt
index 157cc93a0..14a44f2f2 100644
--- a/compiler/src/prog8/compiler/astprocessing/AstExtensions.kt
+++ b/compiler/src/prog8/compiler/astprocessing/AstExtensions.kt
@@ -22,10 +22,6 @@ internal fun Program.checkValid(errors: IErrorReporter, compilerOptions: Compila
 }
 
 internal fun Program.processAstBeforeAsmGeneration(compilerOptions: CompilationOptions, errors: IErrorReporter) {
-    val boolRemover = BoolRemover(this)
-    boolRemover.visit(this)
-    boolRemover.applyModifications()
-
     val fixer = BeforeAsmAstChanger(this, compilerOptions)
     fixer.visit(this)
     while (errors.noErrors() && fixer.applyModifications() > 0) {
diff --git a/compiler/src/prog8/compiler/astprocessing/AstPreprocessor.kt b/compiler/src/prog8/compiler/astprocessing/AstPreprocessor.kt
index 559f659f4..3f0dd7462 100644
--- a/compiler/src/prog8/compiler/astprocessing/AstPreprocessor.kt
+++ b/compiler/src/prog8/compiler/astprocessing/AstPreprocessor.kt
@@ -136,7 +136,7 @@ class AstPreprocessor(val program: Program,
                         }
                     } else {
                         // handle declaration of a single variable
-                        if(decl.value!=null && decl.datatype in NumericDatatypes) {
+                        if(decl.value!=null && (decl.datatype in NumericDatatypes || decl.datatype==DataType.BOOL)) {
                             val target = AssignTarget(IdentifierReference(listOf(decl.name), decl.position), null, null, decl.position)
                             val assign = Assignment(target, decl.value!!, AssignmentOrigin.VARINIT, decl.position)
                             replacements.add(IAstModification.ReplaceNode(decl, assign, scope))
diff --git a/compiler/src/prog8/compiler/astprocessing/BeforeAsmAstChanger.kt b/compiler/src/prog8/compiler/astprocessing/BeforeAsmAstChanger.kt
index 01317c48b..1a574cafb 100644
--- a/compiler/src/prog8/compiler/astprocessing/BeforeAsmAstChanger.kt
+++ b/compiler/src/prog8/compiler/astprocessing/BeforeAsmAstChanger.kt
@@ -26,7 +26,7 @@ internal class BeforeAsmAstChanger(val program: Program, private val options: Co
     }
 
     override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
-        if (decl.type == VarDeclType.VAR && decl.value != null && decl.datatype in NumericDatatypes)
+        if (decl.type == VarDeclType.VAR && decl.value != null && (decl.datatype in NumericDatatypes || decl.datatype==DataType.BOOL))
             throw InternalCompilerException("vardecls for variables, with initial numerical value, should have been rewritten as plain vardecl + assignment $decl")
 
         return noModifications
@@ -104,17 +104,7 @@ internal class BeforeAsmAstChanger(val program: Program, private val options: Co
 
     override fun after(ifElse: IfElse, parent: Node): Iterable<IAstModification> {
         val binExpr = ifElse.condition as? BinaryExpression
-        if(binExpr==null) {
-            // if x  ->  if x!=0
-            val booleanExpr = BinaryExpression(
-                ifElse.condition,
-                "!=",
-                NumericLiteral.optimalInteger(0, ifElse.condition.position),
-                ifElse.condition.position
-            )
-            return listOf(IAstModification.ReplaceNode(ifElse.condition, booleanExpr, ifElse))
-        }
-
+        if(binExpr!=null) {
         if(binExpr.operator !in ComparisonOperators) {
             val constRight = binExpr.right.constValue(program)
             if(constRight!=null) {
@@ -131,20 +121,13 @@ internal class BeforeAsmAstChanger(val program: Program, private val options: Co
                     return listOf(IAstModification.ReplaceNode(ifElse.condition, booleanExpr, ifElse))
                 }
             }
-
-            // if x*5  ->  if x*5 != 0
-            val booleanExpr = BinaryExpression(
-                ifElse.condition,
-                "!=",
-                NumericLiteral.optimalInteger(0, ifElse.condition.position),
-                ifElse.condition.position
-            )
-            return listOf(IAstModification.ReplaceNode(ifElse.condition, booleanExpr, ifElse))
         }
 
         if((binExpr.left as? NumericLiteral)?.number==0.0 &&
             (binExpr.right as? NumericLiteral)?.number!=0.0)
-            throw InternalCompilerException("0==X should have been swapped to if X==0")
+            throw InternalCompilerException("0==X should be just X")
+
+        }
 
         return noModifications
     }
diff --git a/compiler/src/prog8/compiler/astprocessing/BeforeAsmTypecastCleaner.kt b/compiler/src/prog8/compiler/astprocessing/BeforeAsmTypecastCleaner.kt
index 6fe2ab06a..042fc2646 100644
--- a/compiler/src/prog8/compiler/astprocessing/BeforeAsmTypecastCleaner.kt
+++ b/compiler/src/prog8/compiler/astprocessing/BeforeAsmTypecastCleaner.kt
@@ -15,14 +15,6 @@ internal class BeforeAsmTypecastCleaner(val program: Program,
                                         private val errors: IErrorReporter
 ) : AstWalker() {
 
-    override fun before(typecast: TypecastExpression, parent: Node): Iterable<IAstModification> {
-        if(typecast.type == DataType.BOOL) {
-            val notZero = BinaryExpression(typecast.expression, "!=", NumericLiteral(DataType.UBYTE, 0.0, typecast.position), typecast.position)
-            return listOf(IAstModification.ReplaceNode(typecast, notZero, parent))
-        }
-        return noModifications
-    }
-
     override fun after(typecast: TypecastExpression, parent: Node): Iterable<IAstModification> {
         // see if we can remove redundant typecasts (outside of expressions)
         // such as casting byte<->ubyte,  word<->uword  or even redundant casts (sourcetype = target type).
diff --git a/compiler/src/prog8/compiler/astprocessing/BoolRemover.kt b/compiler/src/prog8/compiler/astprocessing/BoolRemover.kt
deleted file mode 100644
index 5a9477268..000000000
--- a/compiler/src/prog8/compiler/astprocessing/BoolRemover.kt
+++ /dev/null
@@ -1,133 +0,0 @@
-package prog8.compiler.astprocessing
-
-import prog8.ast.Node
-import prog8.ast.Program
-import prog8.ast.base.FatalAstException
-import prog8.ast.expressions.*
-import prog8.ast.statements.Subroutine
-import prog8.ast.statements.SubroutineParameter
-import prog8.ast.statements.VarDecl
-import prog8.ast.walk.AstWalker
-import prog8.ast.walk.IAstModification
-import prog8.code.core.*
-
-internal class BoolRemover(val program: Program) : AstWalker() {
-
-    override fun before(typecast: TypecastExpression, parent: Node): Iterable<IAstModification> {
-        if(typecast.type == DataType.BOOL) {
-            val valueDt = typecast.expression.inferType(program).getOrElse { throw FatalAstException("unknown dt") }
-            val notZero = BinaryExpression(typecast.expression, "!=", NumericLiteral(valueDt, 0.0, typecast.position), typecast.position)
-            return listOf(IAstModification.ReplaceNode(typecast, notZero, parent))
-        }
-        return noModifications
-    }
-
-    override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
-        if(decl.datatype==DataType.BOOL) {
-            var newvalue = decl.value
-            if(newvalue is NumericLiteral) {
-                if(newvalue.number!=0.0)
-                    newvalue = NumericLiteral(DataType.UBYTE, 1.0, newvalue.position)
-            }
-            val ubyteDecl = VarDecl(decl.type, decl.origin, DataType.UBYTE, decl.zeropage, null, decl.name, emptyList(),
-                newvalue, decl.sharedWithAsm, false, decl.position)
-            return listOf(IAstModification.ReplaceNode(decl, ubyteDecl, parent))
-        }
-
-        if(decl.datatype==DataType.ARRAY_BOOL) {
-            var newarray = decl.value
-            if(decl.value is ArrayLiteral) {
-                val oldArray = (decl.value as ArrayLiteral).value
-                val convertedArray = oldArray.map {
-                    var number: Expression = it
-                    if (it is NumericLiteral && it.type == DataType.BOOL)
-                        number = NumericLiteral(DataType.UBYTE, if (it.number == 0.0) 0.0 else 1.0, number.position)
-                    number
-                }.toTypedArray()
-                newarray = ArrayLiteral(InferredTypes.InferredType.known(DataType.ARRAY_UB), convertedArray, decl.position)
-            }
-            val ubyteArrayDecl = VarDecl(decl.type, decl.origin, DataType.ARRAY_UB, decl.zeropage, decl.arraysize, decl.name, emptyList(),
-                newarray, decl.sharedWithAsm, decl.splitArray, decl.position)
-            return listOf(IAstModification.ReplaceNode(decl, ubyteArrayDecl, parent))
-        }
-
-        return noModifications
-    }
-
-    override fun after(subroutine: Subroutine, parent: Node): Iterable<IAstModification> {
-        // replace BOOL return type and parameters by UBYTE
-        if(subroutine.returntypes.any { it==DataType.BOOL } || subroutine.parameters.any {it.type==DataType.BOOL}) {
-            val newReturnTypes = subroutine.returntypes.map {
-                if(it==DataType.BOOL) DataType.UBYTE else it
-            }
-            val newParams = subroutine.parameters.map {
-                if(it.type==DataType.BOOL) SubroutineParameter(it.name, DataType.UBYTE, it.position) else it
-            }.toMutableList()
-            val newSubroutine = Subroutine(subroutine.name, newParams, newReturnTypes,
-                subroutine.asmParameterRegisters, subroutine.asmReturnvaluesRegisters, subroutine.asmClobbers,
-                subroutine.asmAddress, subroutine.isAsmSubroutine, subroutine.inline, false, subroutine.statements,
-                subroutine.position)
-            return listOf(IAstModification.ReplaceNode(subroutine, newSubroutine, parent))
-        }
-
-        return noModifications
-    }
-
-    override fun after(expr: BinaryExpression, parent: Node): Iterable<IAstModification> {
-        if(expr.operator in setOf("and", "or", "xor")) {
-            // see if any of the arguments to a logical boolean expression need type casting to bool
-            val mods = mutableListOf<IAstModification>()
-            val newLeft = wrapWithBooleanCastIfNeeded(expr.left, program)
-            val newRight = wrapWithBooleanCastIfNeeded(expr.right, program)
-            if(newLeft!=null)
-                mods += IAstModification.ReplaceNodeSafe(expr.left, newLeft, expr)
-            if(newRight!=null)
-                mods += IAstModification.ReplaceNodeSafe(expr.right, newRight, expr)
-            return mods
-        }
-        return noModifications
-    }
-
-    override fun after(expr: PrefixExpression, parent: Node): Iterable<IAstModification> {
-        if(expr.operator=="not") {
-            val binExpr = expr.expression as? BinaryExpression
-            if(binExpr!=null) {
-                val invertedOperator = invertedComparisonOperator(binExpr.operator)
-                if(invertedOperator!=null) {
-                    val inverted = BinaryExpression(binExpr.left, invertedOperator, binExpr.right, binExpr.position)
-                    return listOf(IAstModification.ReplaceNode(expr, inverted, parent))
-                }
-            }
-            val exprDt = expr.expression.inferType(program).getOrElse { throw FatalAstException("unknown dt") }
-            val nonBoolDt = if(exprDt==DataType.BOOL) DataType.UBYTE else exprDt
-            val equalZero = BinaryExpression(expr.expression, "==", NumericLiteral(nonBoolDt, 0.0, expr.expression.position), expr.expression.position)
-            return listOf(IAstModification.ReplaceNode(expr, equalZero, parent))
-        }
-        return noModifications
-    }
-}
-
-internal fun wrapWithBooleanCastIfNeeded(expr: Expression, program: Program): Expression? {
-    fun isBoolean(expr: Expression): Boolean {
-        return if(expr.inferType(program) istype DataType.BOOL)
-            true
-        else if(expr is NumericLiteral && expr.type in IntegerDatatypes && (expr.number==0.0 || expr.number==1.0))
-            true
-        else if(expr is BinaryExpression && expr.operator in ComparisonOperators + LogicalOperators)
-            true
-        else if(expr is PrefixExpression && expr.operator == "not")
-            true
-        else if(expr is BinaryExpression && expr.operator in BitwiseOperators) {
-            if(isBoolean(expr.left) && isBoolean(expr.right))
-                true
-            else expr.operator=="&" && expr.right.constValue(program)?.number==1.0          //  x & 1   is also a boolean result
-        }
-        else
-            false
-    }
-
-    return if(isBoolean(expr))
-        null
-    else
-        TypecastExpression(expr, DataType.BOOL, true, expr.position)
-}
diff --git a/compiler/src/prog8/compiler/astprocessing/CodeDesugarer.kt b/compiler/src/prog8/compiler/astprocessing/CodeDesugarer.kt
index 2359abf4d..29c9878cb 100644
--- a/compiler/src/prog8/compiler/astprocessing/CodeDesugarer.kt
+++ b/compiler/src/prog8/compiler/astprocessing/CodeDesugarer.kt
@@ -124,6 +124,11 @@ if not CONDITION
     }
 
     override fun after(whileLoop: WhileLoop, parent: Node): Iterable<IAstModification> {
+
+        if(!whileLoop.condition.inferType(program).isBool)
+            errors.err("condition should be a boolean", whileLoop.condition.position)
+
+
         /*
         while true -> repeat
         while false -> discard
diff --git a/compiler/src/prog8/compiler/astprocessing/IntermediateAstMaker.kt b/compiler/src/prog8/compiler/astprocessing/IntermediateAstMaker.kt
index 0a2a34960..be0e980ae 100644
--- a/compiler/src/prog8/compiler/astprocessing/IntermediateAstMaker.kt
+++ b/compiler/src/prog8/compiler/astprocessing/IntermediateAstMaker.kt
@@ -558,8 +558,7 @@ class IntermediateAstMaker(private val program: Program, private val errors: IEr
 
     private fun transform(srcExpr: BinaryExpression): PtBinaryExpression {
         val type = srcExpr.inferType(program).getOrElse { throw FatalAstException("unknown dt") }
-        val actualType = if(type==DataType.BOOL) DataType.UBYTE else type
-        val expr = PtBinaryExpression(srcExpr.operator, actualType, srcExpr.position)
+        val expr = PtBinaryExpression(srcExpr.operator, type, srcExpr.position)
         expr.add(transformExpression(srcExpr.left))
         expr.add(transformExpression(srcExpr.right))
         return expr
@@ -578,27 +577,27 @@ class IntermediateAstMaker(private val program: Program, private val errors: IEr
 
         fun desugar(range: RangeExpression): PtExpression {
             require(range.from.inferType(program)==range.to.inferType(program))
-            val expr = PtBinaryExpression("and", DataType.UBYTE, srcCheck.position)
+            val expr = PtBinaryExpression("and", DataType.BOOL, srcCheck.position)
             val x1 = transformExpression(srcCheck.element)
             val x2 = transformExpression(srcCheck.element)
             val eltDt = srcCheck.element.inferType(program)
             if(eltDt.isInteger) {
-                val low = PtBinaryExpression("<=", DataType.UBYTE, srcCheck.position)
+                val low = PtBinaryExpression("<=", DataType.BOOL, srcCheck.position)
                 low.add(transformExpression(range.from))
                 low.add(x1)
                 expr.add(low)
-                val high = PtBinaryExpression("<=", DataType.UBYTE, srcCheck.position)
+                val high = PtBinaryExpression("<=", DataType.BOOL, srcCheck.position)
                 high.add(x2)
                 high.add(transformExpression(range.to))
                 expr.add(high)
             } else {
-                val low = PtBinaryExpression("<=", DataType.UBYTE, srcCheck.position)
+                val low = PtBinaryExpression("<=", DataType.BOOL, srcCheck.position)
                 val lowFloat = PtTypeCast(DataType.FLOAT, range.from.position)
                 lowFloat.add(transformExpression(range.from))
                 low.add(lowFloat)
                 low.add(x1)
                 expr.add(low)
-                val high = PtBinaryExpression("<=", DataType.UBYTE, srcCheck.position)
+                val high = PtBinaryExpression("<=", DataType.BOOL, srcCheck.position)
                 high.add(x2)
                 val highFLoat = PtTypeCast(DataType.FLOAT, range.to.position)
                 highFLoat.add(transformExpression(range.to))
@@ -655,8 +654,12 @@ class IntermediateAstMaker(private val program: Program, private val errors: IEr
         return mem
     }
 
-    private fun transform(number: NumericLiteral): PtNumber =
-        PtNumber(number.type, number.number, number.position)
+    private fun transform(number: NumericLiteral): PtExpression {
+        return if(number.type==DataType.BOOL)
+            PtBool(number.asBooleanValue, number.position)
+        else
+            PtNumber(number.type, number.number, number.position)
+    }
 
     private fun transform(srcPrefix: PrefixExpression): PtPrefix {
         val type = srcPrefix.inferType(program).getOrElse { throw FatalAstException("unknown dt") }
diff --git a/compiler/src/prog8/compiler/astprocessing/LiteralsToAutoVars.kt b/compiler/src/prog8/compiler/astprocessing/LiteralsToAutoVars.kt
index c3e38151d..4cd513810 100644
--- a/compiler/src/prog8/compiler/astprocessing/LiteralsToAutoVars.kt
+++ b/compiler/src/prog8/compiler/astprocessing/LiteralsToAutoVars.kt
@@ -76,8 +76,8 @@ internal class LiteralsToAutoVars(private val program: Program,
         if(decl.names.size>1) {
             // note: the desugaring of a multi-variable vardecl has to be done here
             // and not in CodeDesugarer, that one is too late (identifiers can't be found otherwise)
-            if(decl.datatype !in NumericDatatypes)
-                errors.err("can only multi declare numeric variables", decl.position)
+            if(decl.datatype !in NumericDatatypesWithBoolean)
+                errors.err("can only multi declare numeric and boolean variables", decl.position)
             if(errors.noErrors()) {
                 // desugar into individual vardecl per name.
                 return decl.desugarMultiDecl().map {
diff --git a/compiler/src/prog8/compiler/astprocessing/NotExpressionAndIfComparisonExprChanger.kt b/compiler/src/prog8/compiler/astprocessing/NotExpressionAndIfComparisonExprChanger.kt
index d94d19887..3e192c6f4 100644
--- a/compiler/src/prog8/compiler/astprocessing/NotExpressionAndIfComparisonExprChanger.kt
+++ b/compiler/src/prog8/compiler/astprocessing/NotExpressionAndIfComparisonExprChanger.kt
@@ -6,13 +6,9 @@ import prog8.ast.base.FatalAstException
 import prog8.ast.expressions.BinaryExpression
 import prog8.ast.expressions.NumericLiteral
 import prog8.ast.expressions.PrefixExpression
-import prog8.ast.expressions.invertCondition
 import prog8.ast.walk.AstWalker
 import prog8.ast.walk.IAstModification
-import prog8.code.core.DataType
-import prog8.code.core.ICompilationTarget
-import prog8.code.core.IErrorReporter
-import prog8.code.core.IntegerDatatypes
+import prog8.code.core.*
 
 internal class NotExpressionAndIfComparisonExprChanger(val program: Program, val errors: IErrorReporter, val compTarget: ICompilationTarget) : AstWalker() {
 
@@ -21,7 +17,7 @@ internal class NotExpressionAndIfComparisonExprChanger(val program: Program, val
             val left = expr.left as? BinaryExpression
             if (left != null) {
                 val rightValue = expr.right.constValue(program)
-                if (rightValue?.number == 0.0 && rightValue.type in IntegerDatatypes) {
+                if (rightValue?.number == 0.0 && rightValue.type in IntegerDatatypesWithBoolean) {
                     if (left.operator == "==" && expr.operator == "==") {
                         // (x==something)==0  -->  x!=something
                         left.operator = "!="
@@ -43,15 +39,11 @@ internal class NotExpressionAndIfComparisonExprChanger(val program: Program, val
             }
         }
 
-        if(expr.operator=="^" && expr.left.inferType(program) istype DataType.BOOL && expr.right.constValue(program)?.number == 1.0) {
-            // boolean ^ 1 --> not boolean
-            return listOf(IAstModification.ReplaceNode(expr, invertCondition(expr.left, program), parent))
-        }
-
-
         // applying De Morgan's laws proved beneficial for the code generator,
         // when the code has one outer 'not' instead of two inner ones.
         if(expr.operator=="or" || expr.operator=="and") {
+
+            // boolean case
             val newOper = if(expr.operator=="or") "and" else "or"
             val leftP = expr.left as? PrefixExpression
             val rightP = expr.right as? PrefixExpression
@@ -62,17 +54,25 @@ internal class NotExpressionAndIfComparisonExprChanger(val program: Program, val
                 val notExpr = PrefixExpression("not", inner, expr.position)
                 return listOf(IAstModification.ReplaceNode(expr, notExpr, parent))
             }
-            val leftB = expr.left as? BinaryExpression
-            val rightB = expr.right as? BinaryExpression
-            if(leftB!=null && leftB.operator=="==" && (leftB.right as? NumericLiteral)?.number==0.0
-                && rightB!=null && rightB.operator=="==" && (rightB.right as? NumericLiteral)?.number==0.0) {
-                // a==0 or b==0  --> (a!=0 and b!=0)==0
-                // a==0 and b==0 --> (a!=0 or b!=0)==0
-                leftB.operator = "!="
-                rightB.operator = "!="
-                val inner = BinaryExpression(leftB, newOper, rightB, expr.position)
-                val notExpr = BinaryExpression(inner, "==", NumericLiteral.optimalInteger(0, expr.position), expr.position)
-                return listOf(IAstModification.ReplaceNode(expr, notExpr, parent))
+
+            // integer case (only if both are the same type)
+            val leftC = expr.left as? BinaryExpression
+            val rightC = expr.right as? BinaryExpression
+            if(leftC!=null && rightC!=null && leftC.operator=="==" && rightC.operator=="==") {
+                if (leftC.right.constValue(program)?.number == 0.0 && rightC.right.constValue(program)?.number == 0.0) {
+                    val leftDt = leftC.left.inferType(program).getOr(DataType.UNDEFINED)
+                    val rightDt = rightC.left.inferType(program).getOr(DataType.UNDEFINED)
+                    if(leftDt==rightDt && leftDt in IntegerDatatypes) {
+                        if (rightC.left.isSimple) {
+                            // x==0 or y==0    ->  (x & y)==0
+                            // x==0 and y==0   ->  (x | y)==0
+                            val newOperator = if(expr.operator=="or") "&" else "|"
+                            val inner = BinaryExpression(leftC.left, newOperator, rightC.left, expr.position)
+                            val compare = BinaryExpression(inner, "==", NumericLiteral(leftDt, 0.0, expr.position), expr.position)
+                            return listOf(IAstModification.ReplaceNode(expr, compare, parent))
+                        }
+                    }
+                }
             }
         }
 
@@ -82,17 +82,50 @@ internal class NotExpressionAndIfComparisonExprChanger(val program: Program, val
     override fun after(expr: PrefixExpression, parent: Node): Iterable<IAstModification> {
         if(expr.operator == "not") {
 
-            // first check if we're already part of a "boolean" expresion (i.e. comparing against 0)
+            // first check if we're already part of a "boolean" expression (i.e. comparing against 0 or 1)
             // if so, simplify THAT whole expression rather than making it more complicated
-            if(parent is BinaryExpression && parent.right.constValue(program)?.number==0.0) {
-                if(parent.operator=="==") {
-                    // (NOT X)==0 --> X!=0
-                    val replacement = BinaryExpression(expr.expression, "!=", NumericLiteral.optimalInteger(0, expr.position), expr.position)
-                    return listOf(IAstModification.ReplaceNode(parent, replacement, parent.parent))
-                } else if(parent.operator=="!=") {
-                    // (NOT X)!=0 --> X==0
-                    val replacement = BinaryExpression(expr.expression, "==", NumericLiteral.optimalInteger(0, expr.position), expr.position)
-                    return listOf(IAstModification.ReplaceNode(parent, replacement, parent.parent))
+            if (parent is BinaryExpression) {
+                if (parent.right.constValue(program)?.number == 0.0) {
+                    if(parent.right.inferType(program).isBool) {
+                        if(parent.operator=="==") {
+                            // (NOT X)==false --> X==true --> X
+                            return listOf(IAstModification.ReplaceNode(parent, expr.expression, parent.parent))
+                        } else if(parent.operator=="!=") {
+                            // (NOT X)!=false --> X!=true -> not X
+                            return listOf(IAstModification.ReplaceNode(parent, expr, parent.parent))
+                        }
+                    } else {
+                        if(parent.operator=="==") {
+                            // (NOT X)==0 --> X!=0
+                            val replacement = BinaryExpression(expr.expression, "!=", NumericLiteral.optimalInteger(0, expr.position), expr.position)
+                            return listOf(IAstModification.ReplaceNode(parent, replacement, parent.parent))
+                        } else if(parent.operator=="!=") {
+                            // (NOT X)!=0 --> X==0
+                            val replacement = BinaryExpression(expr.expression, "==", NumericLiteral.optimalInteger(0, expr.position), expr.position)
+                            return listOf(IAstModification.ReplaceNode(parent, replacement, parent.parent))
+                        }
+                    }
+                }
+                else if (parent.right.constValue(program)?.number == 1.0) {
+                    if(parent.right.inferType(program).isBool) {
+                        if(parent.operator=="==") {
+                            // (NOT X)==true --> X==false --> not X
+                            return listOf(IAstModification.ReplaceNode(parent, expr, parent.parent))
+                        } else if(parent.operator=="!=") {
+                            // (NOT X)!=true --> X!=false -> X
+                            return listOf(IAstModification.ReplaceNode(parent, expr.expression, parent.parent))
+                        }
+                    } else {
+                        if(parent.operator=="==") {
+                            // (NOT X)==1 --> X==0
+                            val replacement = BinaryExpression(expr.expression, "==", NumericLiteral.optimalInteger(0, expr.position), expr.position)
+                            return listOf(IAstModification.ReplaceNode(parent, replacement, parent.parent))
+                        } else if(parent.operator=="!=") {
+                            // (NOT X)!=1 --> X!=0
+                            val replacement = BinaryExpression(expr.expression, "!=", NumericLiteral.optimalInteger(0, expr.position), expr.position)
+                            return listOf(IAstModification.ReplaceNode(parent, replacement, parent.parent))
+                        }
+                    }
                 }
             }
 
@@ -120,13 +153,8 @@ internal class NotExpressionAndIfComparisonExprChanger(val program: Program, val
                     return listOf(IAstModification.ReplaceNode(expr, subBinExpr, parent))
                 }
             }
-
-            // not simpleX -> simpleX==0
-            if(expr.expression.isSimple) {
-                val replacement = BinaryExpression(expr.expression.copy(),"==", NumericLiteral(DataType.UBYTE, 0.0, expr.position), expr.position)
-                return listOf(IAstModification.ReplaceNodeSafe(expr, replacement, parent))
-            }
         }
+
         return noModifications
     }
 }
diff --git a/compiler/src/prog8/compiler/astprocessing/StatementReorderer.kt b/compiler/src/prog8/compiler/astprocessing/StatementReorderer.kt
index 4e870efb5..7fb358f0f 100644
--- a/compiler/src/prog8/compiler/astprocessing/StatementReorderer.kt
+++ b/compiler/src/prog8/compiler/astprocessing/StatementReorderer.kt
@@ -44,7 +44,7 @@ internal class StatementReorderer(
 
     override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
         if (decl.type == VarDeclType.VAR) {
-            if (decl.datatype in NumericDatatypes) {
+            if (decl.datatype in NumericDatatypes || decl.datatype==DataType.BOOL) {
                 if(decl !in declsProcessedWithInitAssignment) {
                     declsProcessedWithInitAssignment.add(decl)
                     if (decl.value == null) {
diff --git a/compiler/src/prog8/compiler/astprocessing/TypecastsAdder.kt b/compiler/src/prog8/compiler/astprocessing/TypecastsAdder.kt
index 3df2b1718..8277b255c 100644
--- a/compiler/src/prog8/compiler/astprocessing/TypecastsAdder.kt
+++ b/compiler/src/prog8/compiler/astprocessing/TypecastsAdder.kt
@@ -24,12 +24,11 @@ class TypecastsAdder(val program: Program, val options: CompilationOptions, val
             val valueDt = declValue.inferType(program)
             if(valueDt isnot decl.datatype) {
 
-                // don't add a typecast on an array initializer value, unless booleans
                 if(valueDt.isInteger && decl.isArray) {
                     if(decl.datatype == DataType.ARRAY_BOOL) {
                         val integer = declValue.constValue(program)?.number
                         if(integer!=null) {
-                            val num = NumericLiteral(DataType.UBYTE, if(integer==0.0) 0.0 else 1.0, declValue.position)
+                            val num = NumericLiteral(DataType.BOOL, if(integer==0.0) 0.0 else 1.0, declValue.position)
                             num.parent = decl
                             decl.value = num
                         }
@@ -87,30 +86,7 @@ class TypecastsAdder(val program: Program, val options: CompilationOptions, val
                 }
             }
 
-            if(expr.operator in LogicalOperators && leftDt.isInteger && rightDt.isInteger) {
-                // see if any of the operands needs conversion to bool
-                val modifications = mutableListOf<IAstModification>()
-                val newLeft = wrapWithBooleanCastIfNeeded(expr.left, program)
-                val newRight = wrapWithBooleanCastIfNeeded(expr.right, program)
-                if(newLeft!=null)
-                    modifications += IAstModification.ReplaceNode(expr.left, newLeft, expr)
-                if(newRight!=null)
-                    modifications += IAstModification.ReplaceNode(expr.right, newRight, expr)
-                if(modifications.isNotEmpty())
-                    return modifications
-            }
             if(leftDt!=rightDt) {
-                // convert bool type to byte if needed
-                if(leftDt istype DataType.BOOL && rightDt.isBytes && !rightDt.istype(DataType.BOOL)) {
-                    if(rightCv==null || (rightCv.number!=1.0 && rightCv.number!=0.0))
-                        return listOf(IAstModification.ReplaceNode(expr.left,
-                            TypecastExpression(expr.left, rightDt.getOr(DataType.UNDEFINED),true, expr.left.position), expr))
-                } else if(leftDt.isBytes && !leftDt.istype(DataType.BOOL) && rightDt istype DataType.BOOL) {
-                    if(leftCv==null || (leftCv.number!=1.0 && leftCv.number!=0.0))
-                        return listOf(IAstModification.ReplaceNode(expr.right,
-                            TypecastExpression(expr.right, leftDt.getOr(DataType.UNDEFINED),true, expr.right.position), expr))
-                }
-
                 // convert a negative operand for bitwise operator to the 2's complement positive number instead
                 if(expr.operator in BitwiseOperators && leftDt.isInteger && rightDt.isInteger) {
                     if(leftCv!=null && leftCv.number<0) {
@@ -169,13 +145,18 @@ class TypecastsAdder(val program: Program, val options: CompilationOptions, val
                     // determine common datatype and add typecast as required to make left and right equal types
                     val (commonDt, toFix) = BinaryExpression.commonDatatype(leftDt.getOr(DataType.UNDEFINED), rightDt.getOr(DataType.UNDEFINED), expr.left, expr.right)
                     if(toFix!=null) {
-                        val modifications = mutableListOf<IAstModification>()
-                        when {
-                            toFix===expr.left -> addTypecastOrCastedValueModification(modifications, expr.left, commonDt, expr)
-                            toFix===expr.right -> addTypecastOrCastedValueModification(modifications, expr.right, commonDt, expr)
-                            else -> throw FatalAstException("confused binary expression side")
+                        if(commonDt==DataType.BOOL) {
+                            // don't automatically cast to bool
+                            errors.err("left and right operands aren't the same type", expr.position)
+                        } else {
+                            val modifications = mutableListOf<IAstModification>()
+                            when {
+                                toFix===expr.left -> addTypecastOrCastedValueModification(modifications, expr.left, commonDt, expr)
+                                toFix===expr.right -> addTypecastOrCastedValueModification(modifications, expr.right, commonDt, expr)
+                                else -> throw FatalAstException("confused binary expression side")
+                            }
+                            return modifications
                         }
-                        return modifications
                     }
                 }
             }
@@ -196,10 +177,6 @@ class TypecastsAdder(val program: Program, val options: CompilationOptions, val
                     if(valuetype in IterableDatatypes && targettype==DataType.UWORD)
                         // special case, don't typecast STR/arrays to UWORD, we support those assignments "directly"
                         return noModifications
-                    if((assignment.value as? BinaryExpression)?.operator in ComparisonOperators && targettype in IntegerDatatypes) {
-                        // special case, treat a boolean comparison result as the same type as the target value to avoid needless casts later
-                        return noModifications
-                    }
                     val modifications = mutableListOf<IAstModification>()
                     addTypecastOrCastedValueModification(modifications, assignment.value, targettype, assignment)
                     return modifications
@@ -244,7 +221,7 @@ class TypecastsAdder(val program: Program, val options: CompilationOptions, val
     }
 
     private fun afterFunctionCallArgs(call: IFunctionCall): Iterable<IAstModification> {
-        // see if a typecast is needed to convert the arguments into the required parameter's type
+        // see if a typecast is needed to convert the arguments into the required parameter type
         val modifications = mutableListOf<IAstModification>()
         val sub = call.target.targetStatement(program)
         val params = when(sub) {
@@ -398,6 +375,8 @@ class TypecastsAdder(val program: Program, val options: CompilationOptions, val
         val sourceDt = expressionToCast.inferType(program).getOr(DataType.UNDEFINED)
         if(sourceDt == requiredType)
             return
+        if(requiredType==DataType.BOOL)
+            return
         if(expressionToCast is NumericLiteral && expressionToCast.type!=DataType.FLOAT) { // refuse to automatically truncate floats
             val castedValue = expressionToCast.cast(requiredType, true)
             if (castedValue.isValid) {
diff --git a/compiler/src/prog8/compiler/astprocessing/VerifyFunctionArgTypes.kt b/compiler/src/prog8/compiler/astprocessing/VerifyFunctionArgTypes.kt
index a0cb04c25..32f197606 100644
--- a/compiler/src/prog8/compiler/astprocessing/VerifyFunctionArgTypes.kt
+++ b/compiler/src/prog8/compiler/astprocessing/VerifyFunctionArgTypes.kt
@@ -105,12 +105,7 @@ internal class VerifyFunctionArgTypes(val program: Program, val errors: IErrorRe
                 if(mismatch>=0) {
                     val actual = argtypes[mismatch]
                     val expected = consideredParamTypes[mismatch]
-                    return if(actual==DataType.BOOL && expected in ByteDatatypes)
-                        null  // a bool is just 1 or 0.
-                    else if(expected==DataType.BOOL && actual==DataType.UBYTE && call.args[mismatch].constValue(program)?.number in setOf(0.0, 1.0))
-                        null  // specifying a 1 or 0 as a BOOL is okay
-                    else
-                        Pair("argument ${mismatch + 1} type mismatch, was: $actual expected: $expected", call.args[mismatch].position)
+                    return Pair("argument ${mismatch + 1} type mismatch, was: $actual expected: $expected", call.args[mismatch].position)
                 }
                 if(target.isAsmSubroutine) {
                     if(target.asmReturnvaluesRegisters.size>1) {
diff --git a/intermediate/src/prog8/intermediate/IRFileReader.kt b/intermediate/src/prog8/intermediate/IRFileReader.kt
index df2e66e1a..2f0eba6f3 100644
--- a/intermediate/src/prog8/intermediate/IRFileReader.kt
+++ b/intermediate/src/prog8/intermediate/IRFileReader.kt
@@ -174,7 +174,7 @@ class IRFileReader {
                 if('.' !in name)
                     throw IRParseException("unscoped varname: $name")
                 val arraysize = if(arrayspec.isNotBlank()) arrayspec.substring(1, arrayspec.length-1).toInt() else null
-                val dt: DataType = parseDatatype(type, arraysize!=null)
+                val dt = parseDatatype(type, arraysize!=null)
                 val zp = if(zpwish.isBlank()) ZeropageWish.DONTCARE else ZeropageWish.valueOf(zpwish)
                 val dummyNode = PtVariable(name, dt, zp, null, null, Position.DUMMY)
                 val newVar = StStaticVariable(name, dt, null, null, null, arraysize, zp, dummyNode)
@@ -210,7 +210,8 @@ class IRFileReader {
                 var initNumeric: Double? = null
                 var initArray: StArray? = null
                 when(dt) {
-                    in NumericDatatypes -> initNumeric = parseIRValue(value).toDouble()
+                    DataType.BOOL -> TODO("parse boolean $value")
+                    in NumericDatatypes -> initNumeric = parseIRValue(value)
                     in ArrayDatatypes -> {
                         initArray = value.split(',').map {
                             if (it.startsWith('@'))
@@ -496,24 +497,24 @@ class IRFileReader {
     private fun parseDatatype(type: String, isArray: Boolean): DataType {
         if(isArray) {
             return when(type) {
+                // note: there are no BOOLEANS anymore in the IR. Only UBYTE.
                 "byte" -> DataType.ARRAY_B
                 "ubyte", "str" -> DataType.ARRAY_UB
                 "word" -> DataType.ARRAY_W
                 "uword" -> DataType.ARRAY_UW
                 "float" -> DataType.ARRAY_F
-                "bool" -> DataType.ARRAY_B
                 "uword_split" -> DataType.ARRAY_UW_SPLIT
                 "word_split" -> DataType.ARRAY_W_SPLIT
                 else -> throw IRParseException("invalid dt")
             }
         } else {
             return when(type) {
+                // note: there are no BOOLEANS anymore in the IR. Only UBYTE.
                 "byte" -> DataType.BYTE
                 "ubyte" -> DataType.UBYTE
                 "word" -> DataType.WORD
                 "uword" -> DataType.UWORD
                 "float" -> DataType.FLOAT
-                "bool" -> DataType.BOOL
                 // note: 'str' should not occur anymore in IR. Should be 'uword'
                 else -> throw IRParseException("invalid dt")
             }
diff --git a/intermediate/src/prog8/intermediate/IRFileWriter.kt b/intermediate/src/prog8/intermediate/IRFileWriter.kt
index d5dfddf24..e2c765c66 100644
--- a/intermediate/src/prog8/intermediate/IRFileWriter.kt
+++ b/intermediate/src/prog8/intermediate/IRFileWriter.kt
@@ -100,7 +100,7 @@ class IRFileWriter(private val irProgram: IRProgram, outfileOverride: Path?) {
                     is IRSubroutine -> {
                         xml.writeStartElement("SUB")
                         xml.writeAttribute("NAME", child.label)
-                        xml.writeAttribute("RETURNTYPE", child.returnType?.toString()?.lowercase() ?: "")
+                        xml.writeAttribute("RETURNTYPE", child.returnType?.typeString(null)?.lowercase() ?: "")
                         xml.writeAttribute("POS", child.position.toString())
                         xml.writeCharacters("\n")
                         xml.writeStartElement("PARAMS")
@@ -247,8 +247,9 @@ class IRFileWriter(private val irProgram: IRProgram, outfileOverride: Path?) {
                 xml.writeCharacters("ubyte[${variable.length}] ${variable.name}_msb=$msbValue zp=${variable.zpwish}\n")
             } else {
                 val value: String = when(variable.dt) {
+                    DataType.BOOL -> variable.onetimeInitializationNumericValue?.toInt()?.toString() ?: ""
                     DataType.FLOAT -> (variable.onetimeInitializationNumericValue ?: "").toString()
-                    in NumericDatatypes -> (variable.onetimeInitializationNumericValue?.toInt()?.toHex() ?: "").toString()
+                    in NumericDatatypes -> variable.onetimeInitializationNumericValue?.toInt()?.toHex() ?: ""
                     DataType.STR -> {
                         val encoded = irProgram.encoding.encodeString(variable.onetimeInitializationStringValue!!.first, variable.onetimeInitializationStringValue.second) + listOf(0u)
                         encoded.joinToString(",") { it.toInt().toString() }
diff --git a/intermediate/src/prog8/intermediate/IRProgram.kt b/intermediate/src/prog8/intermediate/IRProgram.kt
index 34b436097..0988d2124 100644
--- a/intermediate/src/prog8/intermediate/IRProgram.kt
+++ b/intermediate/src/prog8/intermediate/IRProgram.kt
@@ -409,8 +409,8 @@ class IRSubroutine(
         require(!label.startsWith("main.main.")) {"subroutine name invalid main prefix: $label"}
 
         // params and return value should not be str
-        require(parameters.all{ it.dt in NumericDatatypes }) {"non-numeric parameter"}
-        require(returnType==null || returnType in NumericDatatypes) {"non-numeric returntype $returnType"}
+        require(parameters.all{ it.dt in NumericDatatypes || it.dt==DataType.BOOL }) {"non-numeric/non-bool parameter"}
+        require(returnType==null || returnType in NumericDatatypes || returnType==DataType.BOOL) {"non-numeric/non-bool returntype $returnType"}
     }
 
     operator fun plusAssign(chunk: IRCodeChunkBase) {
diff --git a/intermediate/src/prog8/intermediate/IRSymbolTable.kt b/intermediate/src/prog8/intermediate/IRSymbolTable.kt
index ccf9985b0..598bc63f8 100644
--- a/intermediate/src/prog8/intermediate/IRSymbolTable.kt
+++ b/intermediate/src/prog8/intermediate/IRSymbolTable.kt
@@ -80,7 +80,13 @@ class IRSymbolTable {
                 return newArray
             }
             scopedName = variable.scopedName
-            varToadd = IRStStaticVariable(scopedName, variable.dt,
+            val dt = when(variable.dt) {
+                DataType.BOOL -> DataType.UBYTE
+                DataType.ARRAY_BOOL -> DataType.ARRAY_UB
+                else -> variable.dt
+            }
+            varToadd = IRStStaticVariable(scopedName,
+                dt,
                 variable.onetimeInitializationNumericValue,
                 variable.onetimeInitializationStringValue,
                 fixupAddressOfInArray(variable.onetimeInitializationArrayValue),
@@ -166,6 +172,10 @@ class IRStMemVar(name: String,
         }
     }
 
+    init {
+        require(dt!=DataType.BOOL && dt!=DataType.ARRAY_BOOL)
+    }
+
     val typeString: String = dt.typeString(length)
 }
 
@@ -205,6 +215,10 @@ class IRStStaticVariable(name: String,
         }
     }
 
+    init {
+        require(dt!=DataType.BOOL && dt!=DataType.ARRAY_BOOL)
+    }
+
     val uninitialized = onetimeInitializationArrayValue==null && onetimeInitializationStringValue==null && onetimeInitializationNumericValue==null
 
     val typeString: String = dt.typeString(length)
@@ -213,9 +227,17 @@ class IRStStaticVariable(name: String,
 class IRStArrayElement(val number: Double?, val addressOfSymbol: String?) {
     companion object {
         fun from(elt: StArrayElement): IRStArrayElement {
-            return IRStArrayElement(elt.number, elt.addressOfSymbol)
+            if(elt.boolean!=null)
+                return IRStArrayElement(if(elt.boolean==true) 1.0 else 0.0, elt.addressOfSymbol)
+            else
+                return IRStArrayElement(elt.number, elt.addressOfSymbol)
         }
     }
+
+    init {
+        // TODO TEMPORARY
+        require(number!=null || addressOfSymbol!=null)
+    }
 }
 
 typealias IRStArray = List<IRStArrayElement>
diff --git a/intermediate/src/prog8/intermediate/Utils.kt b/intermediate/src/prog8/intermediate/Utils.kt
index cd7ef7b49..191dc35eb 100644
--- a/intermediate/src/prog8/intermediate/Utils.kt
+++ b/intermediate/src/prog8/intermediate/Utils.kt
@@ -9,15 +9,15 @@ import prog8.code.right
 fun DataType.typeString(length: Int?): String {
     val lengthStr = if(length==0) "" else length.toString()
     return when (this) {
-        DataType.BOOL -> "bool"
+        DataType.BOOL -> "ubyte"                // in IR , a boolean is represented by an ubyte.
         DataType.UBYTE -> "ubyte"
         DataType.BYTE -> "byte"
         DataType.UWORD -> "uword"
         DataType.WORD -> "word"
         DataType.LONG -> "long"
         DataType.FLOAT -> "float"
-        DataType.STR -> "ubyte[$lengthStr]"              // here string doesn't exist as a seperate datatype anymore
-        DataType.ARRAY_BOOL -> "bool[$lengthStr]"
+        DataType.STR -> "ubyte[$lengthStr]"             // here string doesn't exist as a seperate datatype anymore
+        DataType.ARRAY_BOOL -> "ubyte[$lengthStr]"      // in IR , a boolean is represented by an ubyte.
         DataType.ARRAY_UB -> "ubyte[$lengthStr]"
         DataType.ARRAY_B -> "byte[$lengthStr]"
         DataType.ARRAY_UW -> "uword[$lengthStr]"