expression splitter integrated into expression simplifier

compiler/src/prog8/compiler/Main.kt

@@ -190,10 +190,9 @@ private fun optimizeAst(programAst: Program, errors: ErrorReporter) {
         // keep optimizing expressions and statements until no more steps remain
         val optsDone1 = programAst.simplifyExpressions()
         val optsDone2 = programAst.optimizeStatements(errors)
-        val optsDone3 = programAst.splitExpressions()
         programAst.constantFold(errors) // because simplified statements and expressions can result in more constants that can be folded away
         errors.handle()
-        if (optsDone1 + optsDone2 + optsDone3 == 0)
+        if (optsDone1 + optsDone2 == 0)
             break
     }
 
@@ -220,7 +219,7 @@ private fun writeAssembly(programAst: Program, errors: ErrorReporter, outputDir:
     programAst.processAstBeforeAsmGeneration(errors)
     errors.handle()
 
-    printAst(programAst) // TODO
+    // printAst(programAst)
 
     CompilationTarget.instance.machine.initializeZeropage(compilerOptions)
     val assembly = CompilationTarget.instance.asmGenerator(

compiler/src/prog8/optimizer/ExpressionSimplifier.kt

@@ -1,11 +1,15 @@
 package prog8.optimizer
 
+import prog8.ast.INameScope
 import prog8.ast.Node
 import prog8.ast.Program
 import prog8.ast.base.*
 import prog8.ast.expressions.*
 import prog8.ast.processing.AstWalker
 import prog8.ast.processing.IAstModification
+import prog8.ast.statements.AssignTarget
+import prog8.ast.statements.Assignment
+import prog8.ast.statements.VarDecl
 import kotlin.math.abs
 import kotlin.math.log2
 import kotlin.math.pow
@@ -275,6 +279,81 @@ internal class ExpressionSimplifier(private val program: Program) : AstWalker()
         return noModifications
     }
 
+
+//    override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
+// TODO somehow if we do this, the resulting code for some programs (cube3d.p8) gets hundreds of bytes larger...:
+//        if(decl.type==VarDeclType.VAR ) {
+//            val binExpr = decl.value as? BinaryExpression
+//            if (binExpr != null && binExpr.operator in augmentAssignmentOperators) {
+//                // split into a vardecl with just the left expression, and an aug. assignment with the right expression.
+//                val augExpr = BinaryExpression(IdentifierReference(listOf(decl.name), decl.position), binExpr.operator, binExpr.right, binExpr.position)
+//                val target = AssignTarget(IdentifierReference(listOf(decl.name), decl.position), null, null, decl.position)
+//                val assign = Assignment(target, augExpr, binExpr.position)
+//                println("SPLIT VARDECL $decl")
+//                return listOf(
+//                        IAstModification.SetExpression({ decl.value = it }, binExpr.left, decl),
+//                        IAstModification.InsertAfter(decl, assign, parent)
+//                )
+//            }
+//        }
+//        return noModifications
+//    }
+
+    override fun after(assignment: Assignment, parent: Node): Iterable<IAstModification> {
+
+        val binExpr = assignment.value as? BinaryExpression
+        if (binExpr != null) {
+/*
+
+reduce the complexity of a (binary) expression that has to be evaluated on the eval stack,
+by attempting to splitting it up into individual simple steps:
+
+
+X =      BinExpr                                   X   =   LeftExpr
+        <operator>                                   followed by
+          /   \              IF 'X' not used       X   =   BinExpr
+         /     \               IN LEFTEXPR ==>             <operator>
+        /       \                                           /   \
+    LeftExpr.  RightExpr.                                  /     \
+      /  \       /  \                                     X     RightExpr.
+    ..  ..      ..  ..
+
+ */
+            if(binExpr.operator in augmentAssignmentOperators && isSimpleTarget(assignment.target, program.namespace)) {
+                if (!assignment.isAugmentable) {
+                    val firstAssign = Assignment(assignment.target, binExpr.left, binExpr.left.position)
+                    val targetExpr = assignment.target.toExpression()
+                    val augExpr = BinaryExpression(targetExpr, binExpr.operator, binExpr.right, binExpr.right.position)
+                    println("SPLIT $assignment")
+                    return listOf(
+                            IAstModification.InsertBefore(assignment, firstAssign, parent),
+                            IAstModification.ReplaceNode(assignment.value, augExpr, assignment))
+                }
+            }
+
+            // TODO further unraveling of binary expression trees into flat statements.
+            // however this should probably be done in a more generic way to also service
+            // the expressiontrees that are not used in an assignment statement...
+        }
+
+        return noModifications
+    }
+
+    private fun isSimpleTarget(target: AssignTarget, namespace: INameScope): Boolean {
+        return when {
+            target.identifier!=null -> target.isInRegularRAM(namespace)
+            target.memoryAddress!=null -> target.isInRegularRAM(namespace)
+            target.arrayindexed!=null -> {
+                val index = target.arrayindexed!!.arrayspec.index
+                if(index is NumericLiteralValue)
+                    target.isInRegularRAM(namespace)
+                else
+                    false
+            }
+            else -> false
+        }
+    }
+
     override fun after(functionCall: FunctionCall, parent: Node): Iterable<IAstModification> {
         if(functionCall.target.nameInSource == listOf("lsb")) {
             val arg = functionCall.args[0]

compiler/src/prog8/optimizer/ExpressionSplitter.kt

@@ -1,91 +0,0 @@
-package prog8.optimizer
-
-import prog8.ast.INameScope
-import prog8.ast.Node
-import prog8.ast.Program
-import prog8.ast.expressions.*
-import prog8.ast.processing.AstWalker
-import prog8.ast.processing.IAstModification
-import prog8.ast.statements.AssignTarget
-import prog8.ast.statements.Assignment
-import prog8.ast.statements.VarDecl
-
-class ExpressionSplitter(private val program: Program) : AstWalker() {
-
-    // TODO once this works, integrate it back into expressionsimplifier
-    override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
-
-// TODO somehow if we do this, the resulting code for some programs (cube3d.p8) gets hundreds of bytes larger...:
-//        if(decl.type==VarDeclType.VAR ) {
-//            val binExpr = decl.value as? BinaryExpression
-//            if (binExpr != null && binExpr.operator in augmentAssignmentOperators) {
-//                // split into a vardecl with just the left expression, and an aug. assignment with the right expression.
-//                val augExpr = BinaryExpression(IdentifierReference(listOf(decl.name), decl.position), binExpr.operator, binExpr.right, binExpr.position)
-//                val target = AssignTarget(IdentifierReference(listOf(decl.name), decl.position), null, null, decl.position)
-//                val assign = Assignment(target, augExpr, binExpr.position)
-//                println("SPLIT VARDECL $decl")
-//                return listOf(
-//                        IAstModification.SetExpression({ decl.value = it }, binExpr.left, decl),
-//                        IAstModification.InsertAfter(decl, assign, parent)
-//                )
-//            }
-//        }
-
-        return emptyList()
-    }
-
-    // TODO once this works, integrate it back into expressionsimplifier
-    override fun after(assignment: Assignment, parent: Node): Iterable<IAstModification> {
-
-        val binExpr = assignment.value as? BinaryExpression
-        if (binExpr != null) {
-/*
-
-reduce the complexity of a (binary) expression that has to be evaluated on the eval stack,
-by attempting to splitting it up into individual simple steps:
-
-
-X =      BinExpr                                   X   =   LeftExpr
-        <operator>                                   followed by
-          /   \              IF 'X' not used       X   =   BinExpr
-         /     \               IN LEFTEXPR ==>             <operator>
-        /       \                                           /   \
-    LeftExpr.  RightExpr.                                  /     \
-      /  \       /  \                                     X     RightExpr.
-    ..  ..      ..  ..
-
- */
-            if(binExpr.operator in augmentAssignmentOperators && isSimpleTarget(assignment.target, program.namespace)) {
-                if (!assignment.isAugmentable) {
-                    val firstAssign = Assignment(assignment.target, binExpr.left, binExpr.left.position)
-                    val targetExpr = assignment.target.toExpression()
-                    val augExpr = BinaryExpression(targetExpr, binExpr.operator, binExpr.right, binExpr.right.position)
-                    return listOf(
-                            IAstModification.InsertBefore(assignment, firstAssign, parent),
-                            IAstModification.ReplaceNode(assignment.value, augExpr, assignment))
-                }
-            }
-
-            // TODO further unraveling of binary expression trees into flat statements.
-            // however this should probably be done in a more generic way to also service
-            // the expressiontrees that are not used in an assignment statement...
-        }
-
-        return emptyList()
-    }
-
-    private fun isSimpleTarget(target: AssignTarget, namespace: INameScope): Boolean {
-        return when {
-            target.identifier!=null -> target.isInRegularRAM(namespace)
-            target.memoryAddress!=null -> target.isInRegularRAM(namespace)
-            target.arrayindexed!=null -> {
-                val index = target.arrayindexed!!.arrayspec.index
-                if(index is NumericLiteralValue)
-                    target.isInRegularRAM(namespace)
-                else
-                    false
-            }
-            else -> false
-        }
-    }
-}

compiler/src/prog8/optimizer/Extensions.kt

@@ -53,10 +53,3 @@ internal fun Program.simplifyExpressions() : Int {
     opti.visit(this)
     return opti.applyModifications()
 }
-
-internal fun Program.splitExpressions() : Int {
-    val splitter = ExpressionSplitter(this)
-    splitter.visit(this)
-    return splitter.applyModifications()
-}
-