Added constant loop-head detection to a switchable optimization option -Oloophead. #246

Implemented for()-loop condition checking before body. Closes #183

src/main/java/dk/camelot64/kickc/Compiler.java

@@ -31,6 +31,9 @@ public class Compiler {
    /** Enable the zero-page coalesce pass. It takes a lot of time, but limits the zero page usage significantly. */
    private boolean enableZeroPageCoalasce = false;
 
+   /** Enable loop head constant optimization. It identified whenever a while()/for() has a constant condition on the first iteration and rewrites it. */
+   private boolean enableLoopHeadConstant = false;
+
    public Compiler() {
       this.program = new Program();
    }
@@ -43,6 +46,10 @@ public class Compiler {
       this.enableZeroPageCoalasce = true;
    }
 
+   void enableLoopHeadConstant() {
+      this.enableLoopHeadConstant = true;
+   }
+
    void setTargetPlatform(TargetPlatform targetPlatform) {
       program.setTargetPlatform(targetPlatform);
    }
@@ -305,10 +312,13 @@ public class Compiler {
       optimizations.add(new PassNSimplifyExpressionWithZero(program));
       optimizations.add(new PassNEliminateUnusedVars(program, true));
       optimizations.add(new Pass2EliminateUnusedBlocks(program));
+      if(enableLoopHeadConstant) {
          optimizations.add(new PassNStatementIndices(program));
          optimizations.add(() -> { program.clearDominators(); return false; });
          optimizations.add(() -> { program.clearLoopSet(); return false; });
          optimizations.add(new Pass2LoopHeadConstantIdentification(program));
+         optimizations.add(() -> { program.clearStatementIndices(); return false; });
+      }
       return optimizations;
    }
 

src/main/java/dk/camelot64/kickc/KickC.java

@@ -66,6 +66,9 @@ public class KickC implements Callable<Void> {
    @CommandLine.Option(names = {"-Ocoalesce"}, description = "Optimization Option. Enables zero-page coalesce pass which limits zero-page usage significantly, but takes a lot of compile time.")
    private boolean optimizeZeroPageCoalesce = false;
 
+   @CommandLine.Option(names = {"-Oloophead"}, description = "Optimization Option. Enables loop-head constant pass which identifies loops where the condition is constant on the first iteration.")
+   private boolean optimizeLoopHeadConstant = false;
+
    @CommandLine.Option(names = {"-Ocache"}, description = "Optimization Option. Enables a fragment cache file.")
    private boolean optimizeFragmentCache = false;
 
@@ -212,6 +215,10 @@ public class KickC implements Callable<Void> {
             compiler.enableZeroPageCoalasce();
          }
 
+         if(optimizeLoopHeadConstant) {
+            compiler.enableLoopHeadConstant();
+         }
+
          System.out.println("Compiling " + kcFile);
          Program program = null;
          try {

src/main/java/dk/camelot64/kickc/model/Program.java

@@ -2,6 +2,7 @@ package dk.camelot64.kickc.model;
 
 import dk.camelot64.kickc.CompileLog;
 import dk.camelot64.kickc.asm.AsmProgram;
+import dk.camelot64.kickc.model.statements.Statement;
 import dk.camelot64.kickc.model.statements.StatementInfos;
 import dk.camelot64.kickc.model.symbols.ProgramScope;
 import dk.camelot64.kickc.model.values.LabelRef;
@@ -302,6 +303,17 @@ public class Program {
       this.statementInfos = null;
    }
 
+   /**
+    * Clear index numbers for all statements in the control flow graph.
+    */
+   public void clearStatementIndices() {
+      for(ControlFlowBlock block : getGraph().getAllBlocks()) {
+         for(Statement statement : block.getStatements()) {
+            statement.setIndex(null);
+         }
+      }
+   }
+
    public SymbolInfos getSymbolInfos() {
       if(symbolInfos==null)
          this.symbolInfos = new PassNCalcSymbolInfos(this).calculate();

src/main/java/dk/camelot64/kickc/model/iterator/ProgramValue.java

@@ -8,11 +8,10 @@ import dk.camelot64.kickc.model.values.*;
 
 /**
  * Any Value in the program being iterated by {@link ProgramValueIterator}.
- *
+ * <p>
  * The Value can be inspected using get() and replaced inside the model using set(val).
- *
+ * <p>
  * The context of the Value can be determined from the sub-class containing it plus the parameters to the ProgramValueHandler.
- *
  */
 public interface ProgramValue {
 
@@ -204,6 +203,11 @@ public interface ProgramValue {
       public void set(Value value) {
          phiVariable.getValues().get(i).setrValue((RValue) value);
       }
+
+      public LabelRef getPredecessor() {
+         return phiVariable.getValues().get(i).getPredecessor();
+      }
+
    }
 
    class PhiValuePredecessor implements ProgramValue {

src/main/java/dk/camelot64/kickc/model/operators/OperatorEqual.java

@@ -3,7 +3,7 @@ package dk.camelot64.kickc.model.operators;
 import dk.camelot64.kickc.model.CompileError;
 import dk.camelot64.kickc.model.types.SymbolType;
 import dk.camelot64.kickc.model.values.ConstantBool;
-import dk.camelot64.kickc.model.values.ConstantInteger;
+import dk.camelot64.kickc.model.values.ConstantEnumerable;
 import dk.camelot64.kickc.model.values.ConstantLiteral;
 
 import java.util.Objects;
@@ -17,8 +17,8 @@ public class OperatorEqual extends OperatorBinary {
 
    @Override
    public ConstantLiteral calculateLiteral(ConstantLiteral left, ConstantLiteral right) {
-      if(left instanceof ConstantInteger && right instanceof ConstantInteger) {
+      if(left instanceof ConstantEnumerable && right instanceof ConstantEnumerable) {
-         return new ConstantBool(Objects.equals(((ConstantInteger) left).getInteger(), ((ConstantInteger) right).getInteger()));
+         return new ConstantBool(Objects.equals(((ConstantEnumerable) left).getInteger(), ((ConstantEnumerable) right).getInteger()));
       }
       throw new CompileError("Calculation not implemented " + left + " " + getOperator() + " " + right);
    }

src/main/java/dk/camelot64/kickc/model/operators/OperatorGreaterThan.java

@@ -2,9 +2,7 @@ package dk.camelot64.kickc.model.operators;
 
 import dk.camelot64.kickc.model.CompileError;
 import dk.camelot64.kickc.model.types.SymbolType;
-import dk.camelot64.kickc.model.values.ConstantBool;
+import dk.camelot64.kickc.model.values.*;
-import dk.camelot64.kickc.model.values.ConstantInteger;
-import dk.camelot64.kickc.model.values.ConstantLiteral;
 
 /** Binary greater-than Operator ( x > y ) */
 public class OperatorGreaterThan extends OperatorBinary {
@@ -15,8 +13,8 @@ public class OperatorGreaterThan extends OperatorBinary {
 
    @Override
    public ConstantLiteral calculateLiteral(ConstantLiteral left, ConstantLiteral right) {
-      if(left instanceof ConstantInteger && right instanceof ConstantInteger) {
+      if(left instanceof ConstantEnumerable && right instanceof ConstantEnumerable) {
-         return new ConstantBool(((ConstantInteger) left).getInteger() > ((ConstantInteger) right).getInteger());
+         return new ConstantBool(((ConstantEnumerable) left).getInteger() > ((ConstantEnumerable) right).getInteger());
       }
       throw new CompileError("Calculation not implemented " + left + " " + getOperator() + " " + right);
    }

src/main/java/dk/camelot64/kickc/model/operators/OperatorGreaterThanEqual.java

@@ -2,9 +2,7 @@ package dk.camelot64.kickc.model.operators;
 
 import dk.camelot64.kickc.model.CompileError;
 import dk.camelot64.kickc.model.types.SymbolType;
-import dk.camelot64.kickc.model.values.ConstantBool;
+import dk.camelot64.kickc.model.values.*;
-import dk.camelot64.kickc.model.values.ConstantInteger;
-import dk.camelot64.kickc.model.values.ConstantLiteral;
 
 /** Binary greater-than-equal Operator ( x >= y ) */
 public class OperatorGreaterThanEqual extends OperatorBinary {
@@ -15,8 +13,8 @@ public class OperatorGreaterThanEqual extends OperatorBinary {
 
    @Override
    public ConstantLiteral calculateLiteral(ConstantLiteral left, ConstantLiteral right) {
-      if(left instanceof ConstantInteger && right instanceof ConstantInteger) {
+      if(left instanceof ConstantEnumerable && right instanceof ConstantEnumerable) {
-         return new ConstantBool(((ConstantInteger) left).getInteger() >= ((ConstantInteger) right).getInteger());
+         return new ConstantBool(((ConstantEnumerable) left).getInteger() >= ((ConstantEnumerable) right).getInteger());
       }
       throw new CompileError("Calculation not implemented " + left + " " + getOperator() + " " + right);
    }

src/main/java/dk/camelot64/kickc/model/operators/OperatorLessThan.java

@@ -3,7 +3,7 @@ package dk.camelot64.kickc.model.operators;
 import dk.camelot64.kickc.model.CompileError;
 import dk.camelot64.kickc.model.types.SymbolType;
 import dk.camelot64.kickc.model.values.ConstantBool;
-import dk.camelot64.kickc.model.values.ConstantInteger;
+import dk.camelot64.kickc.model.values.ConstantEnumerable;
 import dk.camelot64.kickc.model.values.ConstantLiteral;
 
 /** Binary less-than Operator ( x < y ) */
@@ -15,8 +15,8 @@ public class OperatorLessThan extends OperatorBinary {
 
    @Override
    public ConstantLiteral calculateLiteral(ConstantLiteral left, ConstantLiteral right) {
-      if(left instanceof ConstantInteger && right instanceof ConstantInteger) {
+      if(left instanceof ConstantEnumerable && right instanceof ConstantEnumerable) {
-         return new ConstantBool(((ConstantInteger) left).getInteger() < ((ConstantInteger) right).getInteger());
+         return new ConstantBool(((ConstantEnumerable) left).getInteger() < ((ConstantEnumerable) right).getInteger());
       }
       throw new CompileError("Calculation not implemented " + left + " " + getOperator() + " " + right);
    }

src/main/java/dk/camelot64/kickc/model/operators/OperatorLessThanEqual.java

@@ -2,9 +2,7 @@ package dk.camelot64.kickc.model.operators;
 
 import dk.camelot64.kickc.model.CompileError;
 import dk.camelot64.kickc.model.types.SymbolType;
-import dk.camelot64.kickc.model.values.ConstantBool;
+import dk.camelot64.kickc.model.values.*;
-import dk.camelot64.kickc.model.values.ConstantInteger;
-import dk.camelot64.kickc.model.values.ConstantLiteral;
 
 /** Binary less-than-equal Operator ( x <= y ) */
 public class OperatorLessThanEqual extends OperatorBinary {
@@ -15,8 +13,8 @@ public class OperatorLessThanEqual extends OperatorBinary {
 
    @Override
    public ConstantLiteral calculateLiteral(ConstantLiteral left, ConstantLiteral right) {
-      if(left instanceof ConstantInteger && right instanceof ConstantInteger) {
+      if(left instanceof ConstantEnumerable && right instanceof ConstantEnumerable) {
-         return new ConstantBool(((ConstantInteger) left).getInteger() <= ((ConstantInteger) right).getInteger());
+         return new ConstantBool(((ConstantEnumerable) left).getInteger() <= ((ConstantEnumerable) right).getInteger());
       }
       throw new CompileError("Calculation not implemented " + left + " " + getOperator() + " " + right);
    }

src/main/java/dk/camelot64/kickc/model/operators/OperatorNotEqual.java

@@ -2,10 +2,7 @@ package dk.camelot64.kickc.model.operators;
 
 import dk.camelot64.kickc.model.CompileError;
 import dk.camelot64.kickc.model.types.SymbolType;
-import dk.camelot64.kickc.model.values.ConstantBool;
+import dk.camelot64.kickc.model.values.*;
-import dk.camelot64.kickc.model.values.ConstantInteger;
-import dk.camelot64.kickc.model.values.ConstantLiteral;
-import dk.camelot64.kickc.model.values.ConstantPointer;
 
 import java.util.Objects;
 
@@ -18,10 +15,8 @@ public class OperatorNotEqual extends OperatorBinary {
 
    @Override
    public ConstantLiteral calculateLiteral(ConstantLiteral left, ConstantLiteral right) {
-      if(left instanceof ConstantInteger && right instanceof ConstantInteger) {
+      if(left instanceof ConstantEnumerable && right instanceof ConstantEnumerable) {
-         return new ConstantBool(!Objects.equals(((ConstantInteger) left).getInteger(), ((ConstantInteger) right).getInteger()));
+         return new ConstantBool(!Objects.equals(((ConstantEnumerable) left).getInteger(), ((ConstantEnumerable) right).getInteger()));
-      } else if(left instanceof ConstantPointer && right instanceof ConstantPointer) {
-         return new ConstantBool(!Objects.equals(((ConstantPointer) left).getLocation(), ((ConstantPointer) right).getLocation()));
       }
       throw new CompileError("Calculation not implemented " + left + " " + getOperator() + " " + right);
    }

src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java

@@ -945,16 +945,32 @@ public class Pass0GenerateStatementSequence extends KickCBaseVisitor<Object> {
       BlockScope blockScope = getCurrentScope().addBlockScope();
       scopeStack.push(blockScope);
       loopStack.push(new Loop(blockScope));
+      // Add initialization
       this.visit(ctx.forClassicInit());
       KickCParser.StmtForContext stmtForCtx = (KickCParser.StmtForContext) ctx.getParent();
       // Add label
-      Label repeatLabel = getCurrentScope().addLabelIntermediate();
+      Label beginJumpLabel = getCurrentScope().addLabelIntermediate();
+      Label doJumpLabel = getCurrentScope().addLabelIntermediate();
+      Label endJumpLabel = getCurrentScope().addLabelIntermediate();
       List<Comment> comments = getCommentsSymbol(stmtForCtx);
-      StatementLabel repeatTarget = new StatementLabel(repeatLabel.getRef(), StatementSource.forClassic(ctx), comments);
+      StatementLabel repeatTarget = new StatementLabel(beginJumpLabel.getRef(), StatementSource.forClassic(ctx), comments);
       sequence.addStatement(repeatTarget);
+      // Add condition
+      KickCParser.CommaExprContext conditionCtx = ctx.commaExpr(0);
+      PrePostModifierHandler.addPreModifiers(this, conditionCtx, StatementSource.forClassic(ctx));
+      RValue rValue = (RValue) this.visit(conditionCtx);
+      PrePostModifierHandler.addPostModifiers(this, conditionCtx, StatementSource.forClassic(ctx));
+      // Add jump if condition was met
+      StatementConditionalJump doJmpStmt = new StatementConditionalJump(rValue, doJumpLabel.getRef(), StatementSource.forClassic(ctx), Comment.NO_COMMENTS);
+      sequence.addStatement(doJmpStmt);
+      Statement endJmpStmt = new StatementJump(endJumpLabel.getRef(), StatementSource.forClassic(ctx), Comment.NO_COMMENTS);
+      sequence.addStatement(endJmpStmt);
+      StatementLabel doJumpTarget = new StatementLabel(doJumpLabel.getRef(), StatementSource.forClassic(ctx), Comment.NO_COMMENTS);
+      sequence.addStatement(doJumpTarget);
+      // Reuse the begin jump target for continue.
+      loopStack.peek().setContinueLabel(beginJumpLabel);
       // Add body
       addLoopBody(stmtForCtx.stmt());
-      addLoopContinueLabel(loopStack.peek(), ctx);
       // Add increment
       KickCParser.CommaExprContext incrementCtx = ctx.commaExpr(1);
       if(incrementCtx != null) {
@@ -962,14 +978,11 @@ public class Pass0GenerateStatementSequence extends KickCBaseVisitor<Object> {
          this.visit(incrementCtx);
          PrePostModifierHandler.addPostModifiers(this, incrementCtx, StatementSource.forClassic(ctx));
       }
-      // Add condition
+      // Jump back to beginning
-      KickCParser.CommaExprContext conditionCtx = ctx.commaExpr(0);
+      Statement beginJmpStmt = new StatementJump(beginJumpLabel.getRef(), StatementSource.forClassic(ctx), Comment.NO_COMMENTS);
-      PrePostModifierHandler.addPreModifiers(this, conditionCtx, StatementSource.forClassic(ctx));
+      sequence.addStatement(beginJmpStmt);
-      RValue rValue = (RValue) this.visit(conditionCtx);
+      StatementLabel endJumpTarget = new StatementLabel(endJumpLabel.getRef(), StatementSource.forClassic(ctx), Comment.NO_COMMENTS);
-      PrePostModifierHandler.addPostModifiers(this, conditionCtx, StatementSource.forClassic(ctx));
+      sequence.addStatement(endJumpTarget);
-      // Add jump if condition was met
-      StatementConditionalJump doJmpStmt = new StatementConditionalJump(rValue, repeatLabel.getRef(), StatementSource.forClassic(ctx), Comment.NO_COMMENTS);
-      sequence.addStatement(doJmpStmt);
       addDirectives(doJmpStmt, stmtForCtx.directive());
       addLoopBreakLabel(loopStack.pop(), ctx);
       scopeStack.pop();

src/main/java/dk/camelot64/kickc/passes/Pass1AssertUsedVars.java

@@ -39,7 +39,7 @@ public class Pass1AssertUsedVars extends Pass1Base {
       ControlFlowBlock beginBlock = getProgram().getGraph().getBlock(new LabelRef(SymbolRef.BEGIN_BLOCK_NAME));
       assertUsedVars(beginBlock, null, referenceInfos, new LinkedHashSet<>(), new LinkedHashSet<>());
       getProgram().clearVariableReferenceInfos();
-      new PassNStatementIndices(getProgram()).clearStatementIndices();
+      getProgram().clearStatementIndices();
       return false;
    }
 

src/main/java/dk/camelot64/kickc/passes/Pass2ConstantIfs.java

@@ -1,5 +1,6 @@
 package dk.camelot64.kickc.passes;
 
+import dk.camelot64.kickc.model.ConstantNotLiteral;
 import dk.camelot64.kickc.model.ControlFlowBlock;
 import dk.camelot64.kickc.model.Program;
 import dk.camelot64.kickc.model.operators.Operator;
@@ -41,6 +42,7 @@ public class Pass2ConstantIfs extends Pass2SsaOptimization {
                ConstantValue constValue1 = Pass2ConstantIdentification.getConstant(conditional.getrValue1());
                Operator operator = conditional.getOperator();
                ConstantValue constValue2 = Pass2ConstantIdentification.getConstant(conditional.getrValue2());
+               try {
                   if(conditional.getrValue1() == null && operator == null && constValue2 != null) {
                      // Constant condition
                      literal = constValue2.calculateLiteral(getScope());
@@ -53,6 +55,9 @@ public class Pass2ConstantIfs extends Pass2SsaOptimization {
                      ConstantValue constVal = Pass2ConstantIdentification.createBinary(constValue1, (OperatorBinary) operator, constValue2, getScope());
                      literal = constVal.calculateLiteral(getScope());
                   }
+               } catch (ConstantNotLiteral e) {
+                  // not literal - keep as null
+               }
                if(literal!=null && literal instanceof ConstantBool) {
                   // Condition is a constant boolean
                   if(((ConstantBool) literal).getBool()) {

src/main/java/dk/camelot64/kickc/passes/Pass2LoopHeadConstantIdentification.java

@@ -6,10 +6,7 @@ import dk.camelot64.kickc.model.statements.Statement;
 import dk.camelot64.kickc.model.statements.StatementConditionalJump;
 import dk.camelot64.kickc.model.statements.StatementPhiBlock;
 import dk.camelot64.kickc.model.symbols.Variable;
-import dk.camelot64.kickc.model.values.ConstantValue;
+import dk.camelot64.kickc.model.values.*;
-import dk.camelot64.kickc.model.values.LabelRef;
-import dk.camelot64.kickc.model.values.PointerDereference;
-import dk.camelot64.kickc.model.values.VariableRef;
 import dk.camelot64.kickc.passes.utils.Unroller;
 
 import java.util.ArrayList;
@@ -34,10 +31,9 @@ public class Pass2LoopHeadConstantIdentification extends Pass2SsaOptimization {
       for(NaturalLoop loop : loopSet.getLoops()) {
          LabelRef loopHeadRef = loop.getHead();
          ControlFlowBlock loopHeadBlock = getGraph().getBlock(loopHeadRef);
-         //TODO: Fix remaining errors!
+         boolean modified = optimizeLoopHead(loopHeadBlock, loop, variableReferenceInfos);
-         //boolean modified = optimizeLoopHead(loopHeadBlock, loop, variableReferenceInfos);
-         boolean modified = false;
          if(modified) {
+            getProgram().clearVariableReferenceInfos();
             getProgram().clearStatementInfos();
             getProgram().clearLoopSet();
             getProgram().clearDominators();
@@ -45,7 +41,7 @@ public class Pass2LoopHeadConstantIdentification extends Pass2SsaOptimization {
          }
       }
       // TODO: Move to Program
-      new PassNStatementIndices(getProgram()).clearStatementIndices();
+      getProgram().clearStatementIndices();
       return false;
    }
 
@@ -74,6 +70,16 @@ public class Pass2LoopHeadConstantIdentification extends Pass2SsaOptimization {
                      // Predecessor it outside the loop
                      if(value.getrValue() instanceof ConstantValue) {
                         // The value is constant in the predecessor!!
+                        // Make sure it can be calculated as a literal
+                        boolean isLiteral = true;
+                        try {
+                           ConstantValue constantValue = (ConstantValue) value.getrValue();
+                           constantValue.calculateLiteral(getProgram().getScope());
+                        } catch (ConstantNotLiteral e) {
+                           // Not literal
+                           isLiteral = false;
+                        }
+                        if(isLiteral) {
                            // Optimization of the loop head is a good idea for this variable!
                            optimizeVars.add(phiVariable.getVariable());
                         }
@@ -81,6 +87,7 @@ public class Pass2LoopHeadConstantIdentification extends Pass2SsaOptimization {
                   }
                }
             }
+         }
 
          // Is optimization a good idea?
          boolean doOptimize = true;

src/main/java/dk/camelot64/kickc/passes/PassNEliminateUnusedVars.java

@@ -140,7 +140,7 @@ public class PassNEliminateUnusedVars extends Pass2SsaOptimization {
       }
 
       getProgram().clearVariableReferenceInfos();
-      new PassNStatementIndices(getProgram()).clearStatementIndices();
+      getProgram().clearStatementIndices();
       return modified;
    }
 

src/main/java/dk/camelot64/kickc/passes/PassNStatementIndices.java

@@ -29,16 +29,4 @@ public class PassNStatementIndices extends Pass2SsaOptimization {
       return false;
    }
 
-   /**
-    * Clear index numbers for all statements in the control flow graph.
-    */
-   public void clearStatementIndices() {
-      for(ControlFlowBlock block : getProgram().getGraph().getAllBlocks()) {
-         for(Statement statement : block.getStatements()) {
-            statement.setIndex(null);
-         }
-      }
-   }
-
-
 }

src/main/java/dk/camelot64/kickc/passes/calcs/PassNCalcVariableReferenceInfos.java

@@ -183,32 +183,19 @@ public class PassNCalcVariableReferenceInfos extends PassNCalcBase<VariableRefer
     * @param stmt The statement
     * @return Variables defined by the statement
     */
-   private Collection<VariableRef> getDefinedVars(Statement stmt) {
+   public static Collection<VariableRef> getDefinedVars(Statement stmt) {
-      if(stmt instanceof StatementAssignment) {
+      if(stmt instanceof StatementPhiBlock) {
-         StatementAssignment assignment = (StatementAssignment) stmt;
-         LValue lValue = assignment.getlValue();
-         if(lValue instanceof VariableRef) {
-            return Collections.singletonList((VariableRef) lValue);
-         }
-      } else if(stmt instanceof StatementPhiBlock) {
          List<VariableRef> defined = new ArrayList<>();
          StatementPhiBlock phi = (StatementPhiBlock) stmt;
          for(StatementPhiBlock.PhiVariable phiVariable : phi.getPhiVariables()) {
             defined.add(phiVariable.getVariable());
          }
          return defined;
-      } else if(stmt instanceof StatementCall) {
+      } else if(stmt instanceof StatementLValue) {
-         List<VariableRef> defined = new ArrayList<>();
+         LValue lValue = ((StatementLValue) stmt).getlValue();
-         if(((StatementCall) stmt).getlValue() instanceof VariableRef) {
+         if(lValue instanceof VariableRef) {
-            defined.add((VariableRef) ((StatementCall) stmt).getlValue());
+            return Collections.singletonList((VariableRef) lValue);
          }
-         return defined;
-      } else if(stmt instanceof StatementCallPointer) {
-         List<VariableRef> defined = new ArrayList<>();
-         if(((StatementCallPointer) stmt).getlValue() instanceof VariableRef) {
-            defined.add((VariableRef) ((StatementCallPointer) stmt).getlValue());
-         }
-         return defined;
       }
       return new ArrayList<>();
    }

src/main/java/dk/camelot64/kickc/passes/utils/Unroller.java

@@ -10,8 +10,11 @@ import dk.camelot64.kickc.model.symbols.Variable;
 import dk.camelot64.kickc.model.symbols.VariableVersion;
 import dk.camelot64.kickc.model.values.*;
 import dk.camelot64.kickc.passes.AliasReplacer;
+import dk.camelot64.kickc.passes.Pass1GenerateSingleStaticAssignmentForm;
+import dk.camelot64.kickc.passes.calcs.PassNCalcVariableReferenceInfos;
 
 import java.util.*;
+import java.util.concurrent.atomic.AtomicReference;
 
 /**
  * Utility for copying blocks in a program - typically to unroll loops or conditions.
@@ -57,12 +60,10 @@ public class Unroller {
    public void unroll() {
       // 0. Prepare for copying by ensuring that all variables defined in the blocks are represented in PHI-blocks of the successors
       prepare();
-
+      if(program.getLog().isVerboseLoopUnroll()) {
-      if(program.getLog().isVerboseSSAOptimize()) {
+         program.getLog().append("CONTROL FLOW GRAPH (PREPARED FOR LOOP HEAD UNROLL)");
-         program.getLog().append("CONTROL FLOW GRAPH (PREPARED)");
          program.getLog().append(program.getGraph().toString(program));
       }
-
       // 1. Create new versions of all symbols assigned inside the loop
       this.varsOriginalToCopied = copyDefinedVars(unrollBlocks, program);
       // 2. Create new labels for all blocks in the loop
@@ -72,70 +73,144 @@ public class Unroller {
    }
 
    /**
-    * Ensure that all variables defined inside the blocks to be copied has a PHI in successor blocks.
+    * Ensure that variables defined inside and used outside the blocks to be copied has different versions in different successors blocks.
     */
    private void prepare() {
       for(VariableRef origVarRef : getVarsDefinedIn(unrollBlocks, program)) {
          // Find out if the variable is ever referenced outside the loop
          if(isReferencedOutside(origVarRef, unrollBlocks, program)) {
-            //  Add any needed PHI-statements to the successors
+            // Re-version all usages of the specific variable version
-            for(SuccessorTransition successorTransition : getSuccessorTransitions(unrollBlocks, program.getGraph())) {
+            Map<LabelRef, VariableRef> newPhis = new LinkedHashMap<>();
-               ControlFlowBlock successorBlock = program.getGraph().getBlock(successorTransition.successor);
+            Map<LabelRef, VariableRef> varVersions = new LinkedHashMap<>();
-               StatementPhiBlock phiBlock = successorBlock.getPhiBlock();
+            reVersionAllUsages(origVarRef, newPhis, varVersions);
-               // Create a new version of the variable
+            if(program.getLog().isVerboseLoopUnroll()) {
-               Variable origVar = program.getScope().getVariable(origVarRef);
+               program.getLog().append("Created new versions for " + origVarRef + ")");
-               Variable newVar;
+               //program.getLog().append(program.getGraph().toString(program));
-               if(origVar instanceof VariableVersion) {
-                  newVar = ((VariableVersion) origVar).getVersionOf().createVersion();
-               } else {
-                  newVar = origVar.getScope().addVariableIntermediate();
-               }
-               // Replace all references from the new phi and forward
-               forwardReplaceAllUsages(successorTransition.successor, origVarRef, newVar.getRef(), new LinkedHashSet<>());
-               // Create the new phi-variable in the successor phi block
-               StatementPhiBlock.PhiVariable newPhiVar = phiBlock.addPhiVariable(newVar.getRef());
-               newPhiVar.setrValue(successorTransition.predecessor, origVarRef);
-               program.getLog().append("Creating PHI for " + origVarRef.getFullName() + " in block " + successorBlock.getLabel() + " - " + phiBlock.toString(program, false));
-
             }
+            // Recursively fill out & add PHI-functions until they have propagated everywhere needed
+            completePhiFunctions(newPhis, varVersions);
          }
       }
    }
 
    /**
-    * Introduces a new version of a variable - and replaces all uses of the old variable with the new one from a specific point in the control flow graph and forward until the old variable is defined.
+    * Find all usages of a variable and create new versions for each usage.
-    * @param blockRef The block to replace the usage from
+    *
-    * @param origVarRef The original variable
+    * @param origVarRef The original variable where all usages must have new versions
-    * @param newVarRef The new variable replacing the original
+    * @param newPhis Map that will be populated with all new (empty) PHI-variables for the new versionw - these will be populated later.
-    * @param visited All blocks that have already been visited.
+    * @param varVersions Map that will be populated with the version of the origVariable at the end of each block where it has a defined version.
     */
-   private void forwardReplaceAllUsages(LabelRef blockRef, VariableRef origVarRef, VariableRef newVarRef, Set<LabelRef> visited) {
+   private void reVersionAllUsages(VariableRef origVarRef, Map<LabelRef, VariableRef> newPhis, Map<LabelRef, VariableRef> varVersions) {
-      VariableReferenceInfos variableReferenceInfos = program.getVariableReferenceInfos();
+
-      LinkedHashMap<SymbolRef, RValue> aliases = new LinkedHashMap<>();
+      // First add the definition of origVar to varVersions
-      aliases.put(origVarRef, newVarRef);
+      for(ControlFlowBlock block : program.getGraph().getAllBlocks()) {
-      AliasReplacer aliasReplacer = new AliasReplacer(aliases);
-      ControlFlowBlock block = program.getGraph().getBlock(blockRef);
-      if(block!=null) {
          for(Statement statement : block.getStatements()) {
-            Collection<VariableRef> definedVars = variableReferenceInfos.getDefinedVars(statement);
+            Collection<VariableRef> definedVars = PassNCalcVariableReferenceInfos.getDefinedVars(statement);
-            if(definedVars!=null && definedVars.contains(origVarRef)) {
+            if(definedVars.contains(origVarRef)) {
-               // Found definition of the original variable - don't replace any more
+               varVersions.put(block.getLabel(), origVarRef);
-               return;
-            }
-            // Replace any usage in the statement
-            ProgramValueIterator.execute(statement, aliasReplacer, null, block);
             }
          }
-      visited.add(blockRef);
-      if(block!=null) {
-         if(block.getConditionalSuccessor() != null && !visited.contains(block.getConditionalSuccessor())) {
-            forwardReplaceAllUsages(block.getConditionalSuccessor(), origVarRef, newVarRef, visited);
       }
-         if(block.getDefaultSuccessor() != null && !visited.contains(block.getDefaultSuccessor())) {
+      // Next iterate the entire graph ensuring that all usages create new versions (except usages right after the definition)
-            forwardReplaceAllUsages(block.getDefaultSuccessor(), origVarRef, newVarRef, visited);
+      for(ControlFlowBlock block : program.getGraph().getAllBlocks()) {
+         AtomicReference<VariableRef> currentVersion = new AtomicReference<>();
+         // Set current version from map
+         currentVersion.set(varVersions.get(block.getLabel()));
+         for(Statement statement : block.getStatements()) {
+            ProgramValueIterator.execute(statement, (programValue, currentStmt, stmtIt, currentBlock) -> {
+               Value value = programValue.get();
+               if(origVarRef.equals(value)) {
+                  // Found a reference!
+                  if(statement instanceof StatementPhiBlock && programValue instanceof ProgramValue.PhiVariable) {
+                     // This is the definition - don't replace it
+                     currentVersion.set(origVarRef);
+                     varVersions.put(block.getLabel(), origVarRef);
+                  } else if(statement instanceof StatementLValue && programValue instanceof ProgramValue.ProgramValueLValue) {
+                     // This is the definition - don't replace it
+                     currentVersion.set(origVarRef);
+                     varVersions.put(block.getLabel(), origVarRef);
+                  } else if(statement instanceof StatementPhiBlock && programValue instanceof ProgramValue.PhiValue) {
+                     // The reference is inside a PHI-value - we need a version in the predecessor
+                     LabelRef predecessor = ((ProgramValue.PhiValue) programValue).getPredecessor();
+                     VariableRef predecessorVersion = varVersions.get(predecessor);
+                     if(predecessorVersion == null) {
+                        // Add a new PHI to the predecessor
+                        predecessorVersion = createNewVersion(origVarRef);
+                        varVersions.put(predecessor, predecessorVersion);
+                        newPhis.put(predecessor, predecessorVersion);
+                     }
+                     // Use the definition
+                     programValue.set(predecessorVersion);
+                  } else if(currentVersion.get() == null) {
+                     // Found a reference - no definition - create a new version
+                     VariableRef newVarRef = createNewVersion(origVarRef);
+                     currentVersion.set(newVarRef);
+                     varVersions.put(block.getLabel(), newVarRef);
+                     newPhis.put(block.getLabel(), currentVersion.get());
+                     // Use the definition
+                     programValue.set(newVarRef);
+                  } else {
+                     programValue.set(currentVersion.get());
+                  }
+               }
+            }, null, null);
+         }
+      }
+      // Add the new empty PHI-blocks()
+      for(LabelRef blockRef : newPhis.keySet()) {
+         ControlFlowBlock block = program.getGraph().getBlock(blockRef);
+         VariableRef newVersion = newPhis.get(blockRef);
+         block.getPhiBlock().addPhiVariable(newVersion);
+      }
+
+   }
+
+   /**
+    * Create a new version of a variable
+    * @param origVarRef The original variable
+    * @return The new version
+    */
+   private VariableRef createNewVersion(VariableRef origVarRef) {
+      Variable origVar = program.getScope().getVariable(origVarRef);
+      Scope scope = origVar.getScope();
+      VariableRef newVarRef;
+      if(origVarRef.isIntermediate()) {
+         newVarRef = scope.addVariableIntermediate().getRef();
+      } else {
+         newVarRef = ((VariableVersion) origVar).getVersionOf().createVersion().getRef();
+      }
+      return newVarRef;
+   }
+
+   /**
+    * Look through all new phi-functions and fill out their parameters.
+    * Both passed maps are modified
+    *
+    * @param newPhis New (empty) PHI-variables for the new versions that need to be populated
+    * @param varVersions Map with the version of the origVariable at the end of each block where it has a defined version.
+    */
+   private void completePhiFunctions(Map<LabelRef, VariableRef> newPhis, Map<LabelRef, VariableRef> varVersions) {
+      Map<LabelRef, VariableRef> todo = newPhis;
+      while(todo.size() > 0) {
+         Map<LabelRef, VariableRef> doing = todo;
+         todo = new LinkedHashMap<>();
+         for(LabelRef blockRef : doing.keySet()) {
+            VariableRef doingVarRef = doing.get(blockRef);
+            ControlFlowBlock block = program.getGraph().getBlock(blockRef);
+            StatementPhiBlock.PhiVariable doingPhiVariable = block.getPhiBlock().getPhiVariable(doingVarRef);
+            List<ControlFlowBlock> predecessors = Pass1GenerateSingleStaticAssignmentForm.getPhiPredecessors(block, program);
+            for(ControlFlowBlock predecessor : predecessors) {
+               VariableRef predecessorVarRef = varVersions.get(predecessor.getLabel());
+               if(predecessorVarRef == null) {
+                  // Variable has no version in the predecessor block - add a new PHI and populate later!
+                  VariableRef newVarRef = createNewVersion(doingVarRef);
+                  predecessor.getPhiBlock().addPhiVariable(newVarRef);
+                  varVersions.put(predecessor.getLabel(), newVarRef);
+                  todo.put(predecessor.getLabel(), newVarRef);
+                  predecessorVarRef = newVarRef;
+               }
+               doingPhiVariable.setrValue(predecessor.getLabel(), predecessorVarRef);
             }
-         if(block.getCallSuccessor() != null && !visited.contains(block.getCallSuccessor())) {
-            forwardReplaceAllUsages(block.getCallSuccessor(), origVarRef, newVarRef, visited);
          }
       }
    }
@@ -272,7 +347,7 @@ public class Unroller {
    }
 
    /**
-    * Patch the PHI-block of an external successor block. Ensures that the PHI-block also receives data from the new coped block.
+    * Patch the PHI-block of an external successor block. Ensures that the PHI-block also receives data from the new copied block.
     *
     * @param successor The successor block's label
     * @param origBlock The label of the original block

src/test/java/dk/camelot64/kickc/test/TestPrograms.java

@@ -1952,8 +1952,8 @@ public class TestPrograms {
    }
 
    @Test
-   public void testBoolIfs() throws IOException, URISyntaxException {
+   public void testBoolIfsMin() throws IOException, URISyntaxException {
-      compileAndCompare("bool-ifs");
+      compileAndCompare("bool-ifs-min");
    }
 
    @Test

src/test/kc/bool-ifs-min.kc

@@ -0,0 +1,12 @@
+// A test of boolean conditions using && || and !
+
+void main() {
+    const char* screen = 0x400;
+    for( char i : 0..20) {
+        if( (i<10) && ((i&1)==0) ) {
+            screen[i] = '*';
+        }
+    }
+}
+
+

src/test/ref/bool-ifs-min.asm

@@ -0,0 +1,22 @@
+// A test of boolean conditions using && || and !
+.pc = $801 "Basic"
+:BasicUpstart(main)
+.pc = $80d "Program"
+main: {
+    .label screen = $400
+    ldx #0
+  b1:
+    txa
+    and #1
+    cpx #$a
+    bcs b2
+    cmp #0
+    bne b2
+    lda #'*'
+    sta screen,x
+  b2:
+    inx
+    cpx #$15
+    bne b1
+    rts
+}

src/test/ref/bool-ifs-min.cfg

@@ -0,0 +1,30 @@
+@begin: scope:[]  from
+  [0] phi()
+  to:@1
+@1: scope:[]  from @begin
+  [1] phi()
+  [2] call main 
+  to:@end
+@end: scope:[]  from @1
+  [3] phi()
+main: scope:[main]  from @1
+  [4] phi()
+  to:main::@1
+main::@1: scope:[main]  from main main::@2
+  [5] (byte) main::i#2 ← phi( main/(byte) 0 main::@2/(byte) main::i#1 )
+  [6] (byte~) main::$1 ← (byte) main::i#2 & (byte) 1
+  [7] if((byte) main::i#2>=(byte) $a) goto main::@2
+  to:main::@4
+main::@4: scope:[main]  from main::@1
+  [8] if((byte~) main::$1!=(byte) 0) goto main::@2
+  to:main::@3
+main::@3: scope:[main]  from main::@4
+  [9] *((const byte*) main::screen#0 + (byte) main::i#2) ← (byte) '*'
+  to:main::@2
+main::@2: scope:[main]  from main::@1 main::@3 main::@4
+  [10] (byte) main::i#1 ← ++ (byte) main::i#2
+  [11] if((byte) main::i#1!=(byte) $15) goto main::@1
+  to:main::@return
+main::@return: scope:[main]  from main::@2
+  [12] return 
+  to:@return

src/test/ref/bool-ifs-min.log

@@ -0,0 +1,458 @@
+Culled Empty Block (label) main::@4
+
+CONTROL FLOW GRAPH SSA
+@begin: scope:[]  from
+  to:@1
+main: scope:[main]  from @1
+  (byte*) main::screen#0 ← ((byte*)) (number) $400
+  (byte) main::i#0 ← (byte) 0
+  to:main::@1
+main::@1: scope:[main]  from main main::@2
+  (byte) main::i#2 ← phi( main/(byte) main::i#0 main::@2/(byte) main::i#1 )
+  (bool~) main::$0 ← (byte) main::i#2 < (number) $a
+  (number~) main::$1 ← (byte) main::i#2 & (number) 1
+  (bool~) main::$2 ← (number~) main::$1 == (number) 0
+  (bool~) main::$3 ← (bool~) main::$0 && (bool~) main::$2
+  (bool~) main::$4 ← ! (bool~) main::$3
+  if((bool~) main::$4) goto main::@2
+  to:main::@3
+main::@2: scope:[main]  from main::@1 main::@3
+  (byte) main::i#3 ← phi( main::@1/(byte) main::i#2 main::@3/(byte) main::i#4 )
+  (byte) main::i#1 ← (byte) main::i#3 + rangenext(0,$14)
+  (bool~) main::$5 ← (byte) main::i#1 != rangelast(0,$14)
+  if((bool~) main::$5) goto main::@1
+  to:main::@return
+main::@3: scope:[main]  from main::@1
+  (byte) main::i#4 ← phi( main::@1/(byte) main::i#2 )
+  *((byte*) main::screen#0 + (byte) main::i#4) ← (byte) '*'
+  to:main::@2
+main::@return: scope:[main]  from main::@2
+  return 
+  to:@return
+@1: scope:[]  from @begin
+  call main 
+  to:@2
+@2: scope:[]  from @1
+  to:@end
+@end: scope:[]  from @2
+
+SYMBOL TABLE SSA
+(label) @1
+(label) @2
+(label) @begin
+(label) @end
+(void()) main()
+(bool~) main::$0
+(number~) main::$1
+(bool~) main::$2
+(bool~) main::$3
+(bool~) main::$4
+(bool~) main::$5
+(label) main::@1
+(label) main::@2
+(label) main::@3
+(label) main::@return
+(byte) main::i
+(byte) main::i#0
+(byte) main::i#1
+(byte) main::i#2
+(byte) main::i#3
+(byte) main::i#4
+(byte*) main::screen
+(byte*) main::screen#0
+
+Adding number conversion cast (unumber) $a in (bool~) main::$0 ← (byte) main::i#2 < (number) $a
+Adding number conversion cast (unumber) 1 in (number~) main::$1 ← (byte) main::i#2 & (number) 1
+Adding number conversion cast (unumber) main::$1 in (number~) main::$1 ← (byte) main::i#2 & (unumber)(number) 1
+Adding number conversion cast (unumber) 0 in (bool~) main::$2 ← (unumber~) main::$1 == (number) 0
+Successful SSA optimization PassNAddNumberTypeConversions
+Inlining cast (byte*) main::screen#0 ← (byte*)(number) $400
+Successful SSA optimization Pass2InlineCast
+Simplifying constant pointer cast (byte*) 1024
+Simplifying constant integer cast $a
+Simplifying constant integer cast 1
+Simplifying constant integer cast 0
+Successful SSA optimization PassNCastSimplification
+Finalized unsigned number type (byte) $a
+Finalized unsigned number type (byte) 1
+Finalized unsigned number type (byte) 0
+Successful SSA optimization PassNFinalizeNumberTypeConversions
+Inferred type updated to byte in (unumber~) main::$1 ← (byte) main::i#2 & (byte) 1
+Alias (byte) main::i#2 = (byte) main::i#4 
+Successful SSA optimization Pass2AliasElimination
+Alias (byte) main::i#2 = (byte) main::i#3 
+Successful SSA optimization Pass2AliasElimination
+Simple Condition (bool~) main::$5 [12] if((byte) main::i#1!=rangelast(0,$14)) goto main::@1
+Successful SSA optimization Pass2ConditionalJumpSimplification
+Rewriting ! if()-condition to reversed if() [7] (bool~) main::$4 ← ! (bool~) main::$3
+Successful SSA optimization Pass2ConditionalAndOrRewriting
+Rewriting && if()-condition to two if()s [6] (bool~) main::$3 ← (bool~) main::$0 && (bool~) main::$2
+Successful SSA optimization Pass2ConditionalAndOrRewriting
+Constant (const byte*) main::screen#0 = (byte*) 1024
+Constant (const byte) main::i#0 = 0
+Successful SSA optimization Pass2ConstantIdentification
+Resolved ranged next value [10] main::i#1 ← ++ main::i#2 to ++
+Resolved ranged comparison value [12] if(main::i#1!=rangelast(0,$14)) goto main::@1 to (number) $15
+Adding number conversion cast (unumber) $15 in if((byte) main::i#1!=(number) $15) goto main::@1
+Successful SSA optimization PassNAddNumberTypeConversions
+Simplifying constant integer cast $15
+Successful SSA optimization PassNCastSimplification
+Finalized unsigned number type (byte) $15
+Successful SSA optimization PassNFinalizeNumberTypeConversions
+Simple Condition (bool~) main::$0 [4] if((byte) main::i#2<(byte) $a) goto main::@5
+Simple Condition (bool~) main::$2 [10] if((byte~) main::$1==(byte) 0) goto main::@3
+Successful SSA optimization Pass2ConditionalJumpSimplification
+Negating conditional jump and destination [4] if((byte) main::i#2>=(byte) $a) goto main::@2
+Negating conditional jump and destination [10] if((byte~) main::$1!=(byte) 0) goto main::@2
+Successful SSA optimization Pass2ConditionalJumpSequenceImprovement
+Inlining constant with var siblings (const byte) main::i#0
+Constant inlined main::i#0 = (byte) 0
+Successful SSA optimization Pass2ConstantInlining
+Added new block during phi lifting main::@6(between main::@2 and main::@1)
+Adding NOP phi() at start of @begin
+Adding NOP phi() at start of @1
+Adding NOP phi() at start of @2
+Adding NOP phi() at start of @end
+Adding NOP phi() at start of main
+CALL GRAPH
+Calls in [] to main:2 
+
+Created 1 initial phi equivalence classes
+Coalesced [14] main::i#5 ← main::i#1
+Coalesced down to 1 phi equivalence classes
+Culled Empty Block (label) @2
+Culled Empty Block (label) main::@6
+Renumbering block main::@5 to main::@4
+Adding NOP phi() at start of @begin
+Adding NOP phi() at start of @1
+Adding NOP phi() at start of @end
+Adding NOP phi() at start of main
+
+FINAL CONTROL FLOW GRAPH
+@begin: scope:[]  from
+  [0] phi()
+  to:@1
+@1: scope:[]  from @begin
+  [1] phi()
+  [2] call main 
+  to:@end
+@end: scope:[]  from @1
+  [3] phi()
+main: scope:[main]  from @1
+  [4] phi()
+  to:main::@1
+main::@1: scope:[main]  from main main::@2
+  [5] (byte) main::i#2 ← phi( main/(byte) 0 main::@2/(byte) main::i#1 )
+  [6] (byte~) main::$1 ← (byte) main::i#2 & (byte) 1
+  [7] if((byte) main::i#2>=(byte) $a) goto main::@2
+  to:main::@4
+main::@4: scope:[main]  from main::@1
+  [8] if((byte~) main::$1!=(byte) 0) goto main::@2
+  to:main::@3
+main::@3: scope:[main]  from main::@4
+  [9] *((const byte*) main::screen#0 + (byte) main::i#2) ← (byte) '*'
+  to:main::@2
+main::@2: scope:[main]  from main::@1 main::@3 main::@4
+  [10] (byte) main::i#1 ← ++ (byte) main::i#2
+  [11] if((byte) main::i#1!=(byte) $15) goto main::@1
+  to:main::@return
+main::@return: scope:[main]  from main::@2
+  [12] return 
+  to:@return
+
+
+VARIABLE REGISTER WEIGHTS
+(void()) main()
+(byte~) main::$1 11.0
+(byte) main::i
+(byte) main::i#1 16.5
+(byte) main::i#2 11.0
+(byte*) main::screen
+
+Initial phi equivalence classes
+[ main::i#2 main::i#1 ]
+Added variable main::$1 to zero page equivalence class [ main::$1 ]
+Complete equivalence classes
+[ main::i#2 main::i#1 ]
+[ main::$1 ]
+Allocated zp ZP_BYTE:2 [ main::i#2 main::i#1 ]
+Allocated zp ZP_BYTE:3 [ main::$1 ]
+
+INITIAL ASM
+Target platform is c64basic
+  // File Comments
+// A test of boolean conditions using && || and !
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(bbegin)
+.pc = $80d "Program"
+  // Global Constants & labels
+  // @begin
+bbegin:
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+b1_from_bbegin:
+  jmp b1
+  // @1
+b1:
+  // [2] call main 
+  // [4] phi from @1 to main [phi:@1->main]
+main_from_b1:
+  jsr main
+  // [3] phi from @1 to @end [phi:@1->@end]
+bend_from_b1:
+  jmp bend
+  // @end
+bend:
+  // main
+main: {
+    .label screen = $400
+    .label _1 = 3
+    .label i = 2
+    // [5] phi from main to main::@1 [phi:main->main::@1]
+  b1_from_main:
+    // [5] phi (byte) main::i#2 = (byte) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 
+    lda #0
+    sta i
+    jmp b1
+    // [5] phi from main::@2 to main::@1 [phi:main::@2->main::@1]
+  b1_from_b2:
+    // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@2->main::@1#0] -- register_copy 
+    jmp b1
+    // main::@1
+  b1:
+    // [6] (byte~) main::$1 ← (byte) main::i#2 & (byte) 1 -- vbuz1=vbuz2_band_vbuc1 
+    lda #1
+    and i
+    sta _1
+    // [7] if((byte) main::i#2>=(byte) $a) goto main::@2 -- vbuz1_ge_vbuc1_then_la1 
+    lda i
+    cmp #$a
+    bcs b2
+    jmp b4
+    // main::@4
+  b4:
+    // [8] if((byte~) main::$1!=(byte) 0) goto main::@2 -- vbuz1_neq_0_then_la1 
+    lda _1
+    cmp #0
+    bne b2
+    jmp b3
+    // main::@3
+  b3:
+    // [9] *((const byte*) main::screen#0 + (byte) main::i#2) ← (byte) '*' -- pbuc1_derefidx_vbuz1=vbuc2 
+    lda #'*'
+    ldy i
+    sta screen,y
+    jmp b2
+    // main::@2
+  b2:
+    // [10] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuz1=_inc_vbuz1 
+    inc i
+    // [11] if((byte) main::i#1!=(byte) $15) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 
+    lda #$15
+    cmp i
+    bne b1_from_b2
+    jmp breturn
+    // main::@return
+  breturn:
+    // [12] return 
+    rts
+}
+  // File Data
+
+REGISTER UPLIFT POTENTIAL REGISTERS
+Statement [9] *((const byte*) main::screen#0 + (byte) main::i#2) ← (byte) '*' [ main::i#2 ] ( main:2 [ main::i#2 ] ) always clobbers reg byte a 
+Removing always clobbered register reg byte a as potential for zp ZP_BYTE:2 [ main::i#2 main::i#1 ]
+Statement [6] (byte~) main::$1 ← (byte) main::i#2 & (byte) 1 [ main::i#2 main::$1 ] ( main:2 [ main::i#2 main::$1 ] ) always clobbers reg byte a 
+Statement [9] *((const byte*) main::screen#0 + (byte) main::i#2) ← (byte) '*' [ main::i#2 ] ( main:2 [ main::i#2 ] ) always clobbers reg byte a 
+Potential registers zp ZP_BYTE:2 [ main::i#2 main::i#1 ] : zp ZP_BYTE:2 , reg byte x , reg byte y , 
+Potential registers zp ZP_BYTE:3 [ main::$1 ] : zp ZP_BYTE:3 , reg byte a , reg byte x , reg byte y , 
+
+REGISTER UPLIFT SCOPES
+Uplift Scope [main] 27.5: zp ZP_BYTE:2 [ main::i#2 main::i#1 ] 11: zp ZP_BYTE:3 [ main::$1 ] 
+Uplift Scope [] 
+
+Uplifting [main] best 483 combination reg byte x [ main::i#2 main::i#1 ] reg byte a [ main::$1 ] 
+Uplifting [] best 483 combination 
+
+ASSEMBLER BEFORE OPTIMIZATION
+  // File Comments
+// A test of boolean conditions using && || and !
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(bbegin)
+.pc = $80d "Program"
+  // Global Constants & labels
+  // @begin
+bbegin:
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+b1_from_bbegin:
+  jmp b1
+  // @1
+b1:
+  // [2] call main 
+  // [4] phi from @1 to main [phi:@1->main]
+main_from_b1:
+  jsr main
+  // [3] phi from @1 to @end [phi:@1->@end]
+bend_from_b1:
+  jmp bend
+  // @end
+bend:
+  // main
+main: {
+    .label screen = $400
+    // [5] phi from main to main::@1 [phi:main->main::@1]
+  b1_from_main:
+    // [5] phi (byte) main::i#2 = (byte) 0 [phi:main->main::@1#0] -- vbuxx=vbuc1 
+    ldx #0
+    jmp b1
+    // [5] phi from main::@2 to main::@1 [phi:main::@2->main::@1]
+  b1_from_b2:
+    // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@2->main::@1#0] -- register_copy 
+    jmp b1
+    // main::@1
+  b1:
+    // [6] (byte~) main::$1 ← (byte) main::i#2 & (byte) 1 -- vbuaa=vbuxx_band_vbuc1 
+    txa
+    and #1
+    // [7] if((byte) main::i#2>=(byte) $a) goto main::@2 -- vbuxx_ge_vbuc1_then_la1 
+    cpx #$a
+    bcs b2
+    jmp b4
+    // main::@4
+  b4:
+    // [8] if((byte~) main::$1!=(byte) 0) goto main::@2 -- vbuaa_neq_0_then_la1 
+    cmp #0
+    bne b2
+    jmp b3
+    // main::@3
+  b3:
+    // [9] *((const byte*) main::screen#0 + (byte) main::i#2) ← (byte) '*' -- pbuc1_derefidx_vbuxx=vbuc2 
+    lda #'*'
+    sta screen,x
+    jmp b2
+    // main::@2
+  b2:
+    // [10] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx 
+    inx
+    // [11] if((byte) main::i#1!=(byte) $15) goto main::@1 -- vbuxx_neq_vbuc1_then_la1 
+    cpx #$15
+    bne b1_from_b2
+    jmp breturn
+    // main::@return
+  breturn:
+    // [12] return 
+    rts
+}
+  // File Data
+
+ASSEMBLER OPTIMIZATIONS
+Removing instruction jmp b1
+Removing instruction jmp bend
+Removing instruction jmp b1
+Removing instruction jmp b4
+Removing instruction jmp b3
+Removing instruction jmp b2
+Removing instruction jmp breturn
+Succesful ASM optimization Pass5NextJumpElimination
+Replacing label b1_from_b2 with b1
+Removing instruction b1_from_bbegin:
+Removing instruction b1:
+Removing instruction main_from_b1:
+Removing instruction bend_from_b1:
+Removing instruction b1_from_b2:
+Succesful ASM optimization Pass5RedundantLabelElimination
+Removing instruction bend:
+Removing instruction b1_from_main:
+Removing instruction b4:
+Removing instruction b3:
+Removing instruction breturn:
+Succesful ASM optimization Pass5UnusedLabelElimination
+Updating BasicUpstart to call main directly
+Removing instruction jsr main
+Succesful ASM optimization Pass5SkipBegin
+Removing instruction jmp b1
+Succesful ASM optimization Pass5NextJumpElimination
+Removing instruction bbegin:
+Succesful ASM optimization Pass5UnusedLabelElimination
+
+FINAL SYMBOL TABLE
+(label) @1
+(label) @begin
+(label) @end
+(void()) main()
+(byte~) main::$1 reg byte a 11.0
+(label) main::@1
+(label) main::@2
+(label) main::@3
+(label) main::@4
+(label) main::@return
+(byte) main::i
+(byte) main::i#1 reg byte x 16.5
+(byte) main::i#2 reg byte x 11.0
+(byte*) main::screen
+(const byte*) main::screen#0 screen = (byte*) 1024
+
+reg byte x [ main::i#2 main::i#1 ]
+reg byte a [ main::$1 ]
+
+
+FINAL ASSEMBLER
+Score: 291
+
+  // File Comments
+// A test of boolean conditions using && || and !
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(main)
+.pc = $80d "Program"
+  // Global Constants & labels
+  // @begin
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+  // @1
+  // [2] call main 
+  // [4] phi from @1 to main [phi:@1->main]
+  // [3] phi from @1 to @end [phi:@1->@end]
+  // @end
+  // main
+main: {
+    .label screen = $400
+    // [5] phi from main to main::@1 [phi:main->main::@1]
+    // [5] phi (byte) main::i#2 = (byte) 0 [phi:main->main::@1#0] -- vbuxx=vbuc1 
+    ldx #0
+    // [5] phi from main::@2 to main::@1 [phi:main::@2->main::@1]
+    // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@2->main::@1#0] -- register_copy 
+    // main::@1
+  b1:
+    // i&1
+    // [6] (byte~) main::$1 ← (byte) main::i#2 & (byte) 1 -- vbuaa=vbuxx_band_vbuc1 
+    txa
+    and #1
+    // if( (i<10) && ((i&1)==0) )
+    // [7] if((byte) main::i#2>=(byte) $a) goto main::@2 -- vbuxx_ge_vbuc1_then_la1 
+    cpx #$a
+    bcs b2
+    // main::@4
+    // [8] if((byte~) main::$1!=(byte) 0) goto main::@2 -- vbuaa_neq_0_then_la1 
+    cmp #0
+    bne b2
+    // main::@3
+    // screen[i] = '*'
+    // [9] *((const byte*) main::screen#0 + (byte) main::i#2) ← (byte) '*' -- pbuc1_derefidx_vbuxx=vbuc2 
+    lda #'*'
+    sta screen,x
+    // main::@2
+  b2:
+    // for( char i : 0..20)
+    // [10] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx 
+    inx
+    // [11] if((byte) main::i#1!=(byte) $15) goto main::@1 -- vbuxx_neq_vbuc1_then_la1 
+    cpx #$15
+    bne b1
+    // main::@return
+    // }
+    // [12] return 
+    rts
+}
+  // File Data
+

src/test/ref/bool-ifs-min.sym

@@ -0,0 +1,18 @@
+(label) @1
+(label) @begin
+(label) @end
+(void()) main()
+(byte~) main::$1 reg byte a 11.0
+(label) main::@1
+(label) main::@2
+(label) main::@3
+(label) main::@4
+(label) main::@return
+(byte) main::i
+(byte) main::i#1 reg byte x 16.5
+(byte) main::i#2 reg byte x 11.0
+(byte*) main::screen
+(const byte*) main::screen#0 screen = (byte*) 1024
+
+reg byte x [ main::i#2 main::i#1 ]
+reg byte a [ main::$1 ]