diff --git a/src/main/java/dk/camelot64/kickc/Compiler.java b/src/main/java/dk/camelot64/kickc/Compiler.java
index 74e36ab48..a967ce5f9 100644
--- a/src/main/java/dk/camelot64/kickc/Compiler.java
+++ b/src/main/java/dk/camelot64/kickc/Compiler.java
@@ -398,6 +398,7 @@ public class Compiler {
       });
       constantOptimizations.add(new Pass2NopCastInlining(program));
       constantOptimizations.add(new Pass2MultiplyToShiftRewriting(program));
+      constantOptimizations.add(new Pass2ModuloToAndRewriting(program));
       constantOptimizations.add(new Pass2ConstantInlining(program));
       constantOptimizations.add(new Pass2ConstantAdditionElimination(program));
       constantOptimizations.add(new Pass2ConstantSimplification(program));
@@ -553,10 +554,10 @@ public class Compiler {
 
       // Initial Code generation
       new Pass4CodeGeneration(program, false, program.isWarnFragmentMissing()).generate();
-      new Pass4AssertNoCpuClobber(program).check();
       getLog().append("\nINITIAL ASM");
       getLog().append("Target platform is " + program.getTargetPlatform().getName() + " / " + program.getTargetCpu().getName().toUpperCase(Locale.ENGLISH));
       getLog().append(program.getAsm().toString(new AsmProgram.AsmPrintState(true), program));
+      new Pass4AssertNoCpuClobber(program).check();
 
       if(disableUplift) {
          getLog().append("REGISTER UPLIFT DISABLED!");
diff --git a/src/main/java/dk/camelot64/kickc/model/iterator/ProgramExpressionBinary.java b/src/main/java/dk/camelot64/kickc/model/iterator/ProgramExpressionBinary.java
index fcaeae638..7a2627970 100644
--- a/src/main/java/dk/camelot64/kickc/model/iterator/ProgramExpressionBinary.java
+++ b/src/main/java/dk/camelot64/kickc/model/iterator/ProgramExpressionBinary.java
@@ -71,6 +71,12 @@ public interface ProgramExpressionBinary extends ProgramExpression {
     */
    ProgramValue getRightValue();
 
+   /**
+    * Set the binary operator
+    * @param operator new binary operator
+    */
+   void setOperator(OperatorBinary operator);
+
    /** Binary expression assignment rvalue. */
    class ProgramExpressionBinaryAssignmentRValue implements ProgramExpressionBinary {
 
@@ -90,6 +96,11 @@ public interface ProgramExpressionBinary extends ProgramExpression {
          return (OperatorBinary) assignment.getOperator();
       }
 
+      @Override
+      public void setOperator(OperatorBinary operator) {
+         assignment.setOperator(operator);
+      }
+
       @Override
       public RValue getRight() {
          return assignment.getrValue2();
@@ -165,6 +176,11 @@ public interface ProgramExpressionBinary extends ProgramExpression {
          return Operators.ASSIGNMENT;
       }
 
+      @Override
+      public void setOperator(OperatorBinary operator) {
+         throw new InternalError("Not supported!");
+      }
+
       @Override
       public RValue getRight() {
          return (RValue) parameterValue.get();
@@ -234,6 +250,11 @@ public interface ProgramExpressionBinary extends ProgramExpression {
          throw new InternalError("Not supported!");
       }
 
+      @Override
+      public void setOperator(OperatorBinary operator) {
+         throw new InternalError("Not supported!");
+      }
+
       @Override
       public ProgramValue getLeftValue() {
          return new ProgramValue.ProgramValueLValue(assignment);
@@ -302,6 +323,11 @@ public interface ProgramExpressionBinary extends ProgramExpression {
          return (OperatorBinary) conditionalJump.getOperator();
       }
 
+      @Override
+      public void setOperator(OperatorBinary operator) {
+         conditionalJump.setOperator(operator);
+      }
+
       @Override
       public RValue getRight() {
          return conditionalJump.getrValue2();
@@ -368,6 +394,11 @@ public interface ProgramExpressionBinary extends ProgramExpression {
          return getConstantBinary().getOperator();
       }
 
+      @Override
+      public void setOperator(OperatorBinary operator) {
+         getConstantBinary().setOperator(operator);
+      }
+
       @Override
       public RValue getRight() {
          return getConstantBinary().getRight();
@@ -422,6 +453,11 @@ public interface ProgramExpressionBinary extends ProgramExpression {
          return Operators.PLUS;
       }
 
+      @Override
+      public void setOperator(OperatorBinary operator) {
+         throw new InternalError("Not supported!");
+      }
+
       @Override
       public RValue getRight() {
          return getPointerDereferenceIndexed().getIndex();
@@ -492,6 +528,11 @@ public interface ProgramExpressionBinary extends ProgramExpression {
          return Operators.ASSIGNMENT;
       }
 
+      @Override
+      public void setOperator(OperatorBinary operator) {
+         throw new InternalError("Not supported!");
+      }
+
       @Override
       public RValue getRight() {
          return (RValue) phiValue.get();
diff --git a/src/main/java/dk/camelot64/kickc/passes/Pass2ModuloToAndRewriting.java b/src/main/java/dk/camelot64/kickc/passes/Pass2ModuloToAndRewriting.java
new file mode 100644
index 000000000..3034a17bf
--- /dev/null
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass2ModuloToAndRewriting.java
@@ -0,0 +1,62 @@
+package dk.camelot64.kickc.passes;
+
+import dk.camelot64.kickc.model.ConstantNotLiteral;
+import dk.camelot64.kickc.model.Program;
+import dk.camelot64.kickc.model.iterator.ProgramExpressionBinary;
+import dk.camelot64.kickc.model.iterator.ProgramExpressionIterator;
+import dk.camelot64.kickc.model.operators.Operators;
+import dk.camelot64.kickc.model.types.SymbolType;
+import dk.camelot64.kickc.model.values.ConstantBinary;
+import dk.camelot64.kickc.model.values.ConstantInteger;
+import dk.camelot64.kickc.model.values.ConstantLiteral;
+import dk.camelot64.kickc.model.values.ConstantValue;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/** Pass that replaces modulo with factors of 2 with binary and */
+public class Pass2ModuloToAndRewriting extends Pass2SsaOptimization {
+
+   public Pass2ModuloToAndRewriting(Program program) {
+      super(program);
+   }
+
+   @Override
+   public boolean step() {
+      AtomicBoolean optimized = new AtomicBoolean(false);
+
+      ProgramExpressionIterator.execute(getProgram(), (programExpression, currentStmt, stmtIt, currentBlock) -> {
+         if(programExpression instanceof ProgramExpressionBinary) {
+            ProgramExpressionBinary binary = (ProgramExpressionBinary) programExpression;
+            if(binary.getOperator().equals(Operators.MODULO) && binary.getRight() instanceof ConstantValue) {
+               final ConstantLiteral constantLiteral = getConstantLiteral((ConstantValue) binary.getRight());
+               if(constantLiteral instanceof ConstantInteger) {
+                  Long constantInt = ((ConstantInteger) constantLiteral).getInteger();
+                  double power2 = Math.log(constantInt) / Math.log(2);
+                  if(power2 >= 0.0 && Math.round(power2) == power2) {
+                     // Modulo whole power of 2
+                     binary.setOperator(Operators.BOOL_AND);
+                     binary.getRightValue().set(new ConstantBinary((ConstantValue) binary.getRight(), Operators.MINUS, new ConstantInteger(1l, SymbolType.BYTE)));
+                     getLog().append("Rewriting power 2 modulo to use AND " + binary.getLeft().toString()+" "+binary.getOperator().toString()+" "+binary.getRight().toString());
+                     optimized.set(true);
+                  }
+               }
+            }
+         }
+      });
+      return optimized.get();
+   }
+
+   /**
+    * Get the constant literal value for a constant value - or null if not possible
+    *
+    * @param constantValue The constant value
+    * @return The constant literal value for RValue2 (or null)
+    */
+   private ConstantLiteral getConstantLiteral(ConstantValue constantValue) {
+      try {
+         return constantValue.calculateLiteral(getScope());
+      } catch(ConstantNotLiteral e) {
+         return null;
+      }
+   }
+}
diff --git a/src/main/java/dk/camelot64/kickc/passes/Pass4InterruptClobberFix.java b/src/main/java/dk/camelot64/kickc/passes/Pass4InterruptClobberFix.java
index c721750f0..fe5f437bb 100644
--- a/src/main/java/dk/camelot64/kickc/passes/Pass4InterruptClobberFix.java
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass4InterruptClobberFix.java
@@ -115,9 +115,10 @@ public class Pass4InterruptClobberFix extends Pass2Base {
       while(entryLines.hasNext()) {
          AsmLine line = entryLines.next();
          for(String notClobberedReg : notClobberedRegisters) {
-            if(line.getAsm().contains(notClobberedReg)) {
+            final String lineAsm = line.getAsm();
+            if(lineAsm.contains("ld"+notClobberedReg) || lineAsm.contains("st"+notClobberedReg) || lineAsm.contains("reg"+notClobberedReg)) {
                // Found an A/X/Y in the asm where A/X/Y is not clobbered - remove the line
-               getLog().append("Removing interrupt register storage "+line.toString()+" in CHU"+interruptEntryExit.getIndex()+" "+interruptEntryExit.getSource());
+               getLog().append("Removing interrupt register storage "+line.toString()+" in "+interruptEntryExit.getIndex()+" "+interruptEntryExit.getSource());
                entryLines.remove();
             }
          }
diff --git a/src/main/java/dk/camelot64/kickc/passes/calcs/PassNCalcVariableRegisterWeight.java b/src/main/java/dk/camelot64/kickc/passes/calcs/PassNCalcVariableRegisterWeight.java
index 7602bdb4c..cb2a5c8ef 100644
--- a/src/main/java/dk/camelot64/kickc/passes/calcs/PassNCalcVariableRegisterWeight.java
+++ b/src/main/java/dk/camelot64/kickc/passes/calcs/PassNCalcVariableRegisterWeight.java
@@ -80,7 +80,7 @@ public class PassNCalcVariableRegisterWeight extends PassNCalcBase<VariableRegis
       int depth = loopSet.getMaxLoopDepth(block);
       double w = 1.0 + Math.pow(10.0, depth);
       LiveRange liveRange = liveRangeVariables.getLiveRange(variable);
-      double s = liveRange.size();
+      double s = liveRange==null?0.0:liveRange.size();
       if(s < 0.01) {
          s = 0.1;
       }
diff --git a/src/test/kc/double-indexing-arrays.kc b/src/test/kc/double-indexing-arrays.kc
index d054cc011..539884ec2 100644
--- a/src/test/kc/double-indexing-arrays.kc
+++ b/src/test/kc/double-indexing-arrays.kc
@@ -8,7 +8,7 @@ byte* SCREEN = $0400;
 byte* COLS = $d800;
 
 void main() {
-    for (byte register(y) x: 0..200) {
+    for (byte x: 0..200) {
         SCREEN[x] = MAPDATA[x];
         COLS[x] = COLORMAP1[MAPDATA[x]];
         SCREEN[200+x] = MAPDATA[200+x];
diff --git a/src/test/ref/assignment-compound.asm b/src/test/ref/assignment-compound.asm
index 3793bd37d..7afa74aca 100644
--- a/src/test/ref/assignment-compound.asm
+++ b/src/test/ref/assignment-compound.asm
@@ -29,27 +29,27 @@ main: {
     sta.z test.a
     jsr test
     ldx #5
-    lda #mod((3+1-1)*6/2,2)
+    lda #(3+1-1)*6/2&2-1
     sta.z test.a
     jsr test
     ldx #6
-    lda #mod((3+1-1)*6/2,2)<<2
+    lda #((3+1-1)*6/2&2-1)<<2
     sta.z test.a
     jsr test
     ldx #7
-    lda #mod((3+1-1)*6/2,2)<<2>>1
+    lda #((3+1-1)*6/2&2-1)<<2>>1
     sta.z test.a
     jsr test
     ldx #8
-    lda #mod((3+1-1)*6/2,2)<<2>>1^6
+    lda #((3+1-1)*6/2&2-1)<<2>>1^6
     sta.z test.a
     jsr test
     ldx #9
-    lda #mod((3+1-1)*6/2,2)<<2>>1^6|1
+    lda #((3+1-1)*6/2&2-1)<<2>>1^6|1
     sta.z test.a
     jsr test
     ldx #$a
-    lda #(mod((3+1-1)*6/2,2)<<2>>1^6|1)&1
+    lda #(((3+1-1)*6/2&2-1)<<2>>1^6|1)&1
     sta.z test.a
     jsr test
     rts
diff --git a/src/test/ref/assignment-compound.cfg b/src/test/ref/assignment-compound.cfg
index 857bb2975..2ff233022 100644
--- a/src/test/ref/assignment-compound.cfg
+++ b/src/test/ref/assignment-compound.cfg
@@ -60,7 +60,7 @@ main::@return: scope:[main]  from main::@10
 (void()) test((byte) test::i , (byte) test::a)
 test: scope:[test]  from main main::@1 main::@10 main::@2 main::@3 main::@4 main::@5 main::@6 main::@7 main::@8 main::@9
   [27] (byte) test::i#11 ← phi( main/(byte) 0 main::@1/(byte) 1 main::@10/(byte) $a main::@2/(byte) 2 main::@3/(byte) 3 main::@4/(byte) 4 main::@5/(byte) 5 main::@6/(byte) 6 main::@7/(byte) 7 main::@8/(byte) 8 main::@9/(byte) 9 )
-  [27] (byte) test::a#11 ← phi( main/(byte) 3 main::@1/(byte) 3+(byte) 1 main::@10/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1&(byte) 1 main::@2/(byte) 3+(byte) 1-(byte) 1 main::@3/(byte) 3+(byte) 1-(byte) 1*(byte) 6 main::@4/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2 main::@5/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2 main::@6/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2 main::@7/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1 main::@8/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6 main::@9/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1 )
+  [27] (byte) test::a#11 ← phi( main/(byte) 3 main::@1/(byte) 3+(byte) 1 main::@10/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1&(byte) 1 main::@2/(byte) 3+(byte) 1-(byte) 1 main::@3/(byte) 3+(byte) 1-(byte) 1*(byte) 6 main::@4/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2 main::@5/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1 main::@6/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2 main::@7/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1 main::@8/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6 main::@9/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1 )
   [28] *((const byte*) screen1 + (byte) test::i#11) ← (byte) test::a#11
   [29] *((const byte*) screen2#0 + (byte) test::i#11) ← *((const byte*) ref + (byte) test::i#11)
   [30] if(*((const byte*) ref + (byte) test::i#11)==(byte) test::a#11) goto test::@1
diff --git a/src/test/ref/assignment-compound.log b/src/test/ref/assignment-compound.log
index e7f1eda01..b8b17b170 100644
--- a/src/test/ref/assignment-compound.log
+++ b/src/test/ref/assignment-compound.log
@@ -446,6 +446,8 @@ Successful SSA optimization Pass2ConstantIdentification
 Constant (const byte) test::i#10 = main::i#10
 Constant (const byte) test::a#10 = main::a#10
 Successful SSA optimization Pass2ConstantIdentification
+Rewriting power 2 modulo to use AND main::a#15 & 2-1
+Successful SSA optimization Pass2ModuloToAndRewriting
 Inlining constant with different constant siblings (const byte) main::i#0
 Inlining constant with different constant siblings (const byte) main::a#0
 Inlining constant with different constant siblings (const byte) main::i#1
@@ -491,38 +493,38 @@ Inlining constant with var siblings (const byte) test::a#9
 Inlining constant with var siblings (const byte) test::i#10
 Inlining constant with var siblings (const byte) test::a#10
 Constant inlined test::i#1 = ++(byte) 0
-Constant inlined test::a#8 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6
+Constant inlined test::a#8 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6
 Constant inlined test::i#0 = (byte) 0
-Constant inlined test::a#9 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1
+Constant inlined test::a#9 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1
 Constant inlined test::i#3 = ++++++(byte) 0
 Constant inlined test::i#2 = ++++(byte) 0
 Constant inlined test::a#4 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2
 Constant inlined main::i#21 = ++++++++++++++++++(byte) 0
-Constant inlined test::a#5 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2
-Constant inlined test::a#6 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2
-Constant inlined test::a#7 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1
+Constant inlined test::a#5 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1
+Constant inlined test::a#6 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2
+Constant inlined test::a#7 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1
 Constant inlined main::i#20 = ++++++++++++++++(byte) 0
 Constant inlined test::i#9 = ++++++++++++++++++(byte) 0
 Constant inlined test::i#8 = ++++++++++++++++(byte) 0
-Constant inlined main::a#20 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1
-Constant inlined test::a#10 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1&(byte) 1
+Constant inlined main::a#20 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1
+Constant inlined test::a#10 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1&(byte) 1
 Constant inlined test::i#5 = ++++++++++(byte) 0
 Constant inlined test::i#4 = ++++++++(byte) 0
 Constant inlined test::i#7 = ++++++++++++++(byte) 0
 Constant inlined test::i#6 = ++++++++++++(byte) 0
 Constant inlined test::i#10 = ++++++++++++++++++++(byte) 0
 Constant inlined main::a#0 = (byte) 3
-Constant inlined main::a#19 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6
-Constant inlined main::a#18 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1
-Constant inlined main::a#17 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2
+Constant inlined main::a#19 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6
+Constant inlined main::a#18 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1
+Constant inlined main::a#17 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2
 Constant inlined main::a#1 = (byte) 3+(byte) 1
-Constant inlined main::a#16 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2
+Constant inlined main::a#16 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1
 Constant inlined main::i#0 = (byte) 0
 Constant inlined main::i#1 = ++(byte) 0
 Constant inlined main::i#14 = ++++(byte) 0
 Constant inlined main::i#15 = ++++++(byte) 0
 Constant inlined main::i#10 = ++++++++++++++++++++(byte) 0
-Constant inlined main::a#10 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1&(byte) 1
+Constant inlined main::a#10 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1&(byte) 1
 Constant inlined main::a#15 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2
 Constant inlined main::i#18 = ++++++++++++(byte) 0
 Constant inlined main::a#14 = (byte) 3+(byte) 1-(byte) 1*(byte) 6
@@ -661,7 +663,7 @@ main::@return: scope:[main]  from main::@10
 (void()) test((byte) test::i , (byte) test::a)
 test: scope:[test]  from main main::@1 main::@10 main::@2 main::@3 main::@4 main::@5 main::@6 main::@7 main::@8 main::@9
   [27] (byte) test::i#11 ← phi( main/(byte) 0 main::@1/(byte) 1 main::@10/(byte) $a main::@2/(byte) 2 main::@3/(byte) 3 main::@4/(byte) 4 main::@5/(byte) 5 main::@6/(byte) 6 main::@7/(byte) 7 main::@8/(byte) 8 main::@9/(byte) 9 )
-  [27] (byte) test::a#11 ← phi( main/(byte) 3 main::@1/(byte) 3+(byte) 1 main::@10/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1&(byte) 1 main::@2/(byte) 3+(byte) 1-(byte) 1 main::@3/(byte) 3+(byte) 1-(byte) 1*(byte) 6 main::@4/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2 main::@5/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2 main::@6/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2 main::@7/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1 main::@8/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6 main::@9/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1 )
+  [27] (byte) test::a#11 ← phi( main/(byte) 3 main::@1/(byte) 3+(byte) 1 main::@10/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1&(byte) 1 main::@2/(byte) 3+(byte) 1-(byte) 1 main::@3/(byte) 3+(byte) 1-(byte) 1*(byte) 6 main::@4/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2 main::@5/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1 main::@6/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2 main::@7/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1 main::@8/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6 main::@9/(byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1 )
   [28] *((const byte*) screen1 + (byte) test::i#11) ← (byte) test::a#11
   [29] *((const byte*) screen2#0 + (byte) test::i#11) ← *((const byte*) ref + (byte) test::i#11)
   [30] if(*((const byte*) ref + (byte) test::i#11)==(byte) test::a#11) goto test::@1
@@ -810,8 +812,8 @@ main: {
     // [27] phi (byte) test::i#11 = (byte) 5 [phi:main::@5->test#0] -- vbuz1=vbuc1 
     lda #5
     sta.z test.i
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2 [phi:main::@5->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1 [phi:main::@5->test#1] -- vbuz1=vbuc1 
+    lda #(3+1-1)*6/2&2-1
     sta.z test.a
     jsr test
     // [16] phi from main::@5 to main::@6 [phi:main::@5->main::@6]
@@ -825,8 +827,8 @@ main: {
     // [27] phi (byte) test::i#11 = (byte) 6 [phi:main::@6->test#0] -- vbuz1=vbuc1 
     lda #6
     sta.z test.i
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2 [phi:main::@6->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)<<2
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2 [phi:main::@6->test#1] -- vbuz1=vbuc1 
+    lda #((3+1-1)*6/2&2-1)<<2
     sta.z test.a
     jsr test
     // [18] phi from main::@6 to main::@7 [phi:main::@6->main::@7]
@@ -840,8 +842,8 @@ main: {
     // [27] phi (byte) test::i#11 = (byte) 7 [phi:main::@7->test#0] -- vbuz1=vbuc1 
     lda #7
     sta.z test.i
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1 [phi:main::@7->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)<<2>>1
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1 [phi:main::@7->test#1] -- vbuz1=vbuc1 
+    lda #((3+1-1)*6/2&2-1)<<2>>1
     sta.z test.a
     jsr test
     // [20] phi from main::@7 to main::@8 [phi:main::@7->main::@8]
@@ -855,8 +857,8 @@ main: {
     // [27] phi (byte) test::i#11 = (byte) 8 [phi:main::@8->test#0] -- vbuz1=vbuc1 
     lda #8
     sta.z test.i
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6 [phi:main::@8->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)<<2>>1^6
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6 [phi:main::@8->test#1] -- vbuz1=vbuc1 
+    lda #((3+1-1)*6/2&2-1)<<2>>1^6
     sta.z test.a
     jsr test
     // [22] phi from main::@8 to main::@9 [phi:main::@8->main::@9]
@@ -870,8 +872,8 @@ main: {
     // [27] phi (byte) test::i#11 = (byte) 9 [phi:main::@9->test#0] -- vbuz1=vbuc1 
     lda #9
     sta.z test.i
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1 [phi:main::@9->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)<<2>>1^6|1
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1 [phi:main::@9->test#1] -- vbuz1=vbuc1 
+    lda #((3+1-1)*6/2&2-1)<<2>>1^6|1
     sta.z test.a
     jsr test
     // [24] phi from main::@9 to main::@10 [phi:main::@9->main::@10]
@@ -885,8 +887,8 @@ main: {
     // [27] phi (byte) test::i#11 = (byte) $a [phi:main::@10->test#0] -- vbuz1=vbuc1 
     lda #$a
     sta.z test.i
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1&(byte) 1 [phi:main::@10->test#1] -- vbuz1=vbuc1 
-    lda #(mod((3+1-1)*6/2,2)<<2>>1^6|1)&1
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1&(byte) 1 [phi:main::@10->test#1] -- vbuz1=vbuc1 
+    lda #(((3+1-1)*6/2&2-1)<<2>>1^6|1)&1
     sta.z test.a
     jsr test
     jmp __breturn
@@ -1068,8 +1070,8 @@ main: {
   test_from___b5:
     // [27] phi (byte) test::i#11 = (byte) 5 [phi:main::@5->test#0] -- vbuxx=vbuc1 
     ldx #5
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2 [phi:main::@5->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1 [phi:main::@5->test#1] -- vbuz1=vbuc1 
+    lda #(3+1-1)*6/2&2-1
     sta.z test.a
     jsr test
     // [16] phi from main::@5 to main::@6 [phi:main::@5->main::@6]
@@ -1082,8 +1084,8 @@ main: {
   test_from___b6:
     // [27] phi (byte) test::i#11 = (byte) 6 [phi:main::@6->test#0] -- vbuxx=vbuc1 
     ldx #6
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2 [phi:main::@6->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)<<2
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2 [phi:main::@6->test#1] -- vbuz1=vbuc1 
+    lda #((3+1-1)*6/2&2-1)<<2
     sta.z test.a
     jsr test
     // [18] phi from main::@6 to main::@7 [phi:main::@6->main::@7]
@@ -1096,8 +1098,8 @@ main: {
   test_from___b7:
     // [27] phi (byte) test::i#11 = (byte) 7 [phi:main::@7->test#0] -- vbuxx=vbuc1 
     ldx #7
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1 [phi:main::@7->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)<<2>>1
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1 [phi:main::@7->test#1] -- vbuz1=vbuc1 
+    lda #((3+1-1)*6/2&2-1)<<2>>1
     sta.z test.a
     jsr test
     // [20] phi from main::@7 to main::@8 [phi:main::@7->main::@8]
@@ -1110,8 +1112,8 @@ main: {
   test_from___b8:
     // [27] phi (byte) test::i#11 = (byte) 8 [phi:main::@8->test#0] -- vbuxx=vbuc1 
     ldx #8
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6 [phi:main::@8->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)<<2>>1^6
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6 [phi:main::@8->test#1] -- vbuz1=vbuc1 
+    lda #((3+1-1)*6/2&2-1)<<2>>1^6
     sta.z test.a
     jsr test
     // [22] phi from main::@8 to main::@9 [phi:main::@8->main::@9]
@@ -1124,8 +1126,8 @@ main: {
   test_from___b9:
     // [27] phi (byte) test::i#11 = (byte) 9 [phi:main::@9->test#0] -- vbuxx=vbuc1 
     ldx #9
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1 [phi:main::@9->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)<<2>>1^6|1
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1 [phi:main::@9->test#1] -- vbuz1=vbuc1 
+    lda #((3+1-1)*6/2&2-1)<<2>>1^6|1
     sta.z test.a
     jsr test
     // [24] phi from main::@9 to main::@10 [phi:main::@9->main::@10]
@@ -1138,8 +1140,8 @@ main: {
   test_from___b10:
     // [27] phi (byte) test::i#11 = (byte) $a [phi:main::@10->test#0] -- vbuxx=vbuc1 
     ldx #$a
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1&(byte) 1 [phi:main::@10->test#1] -- vbuz1=vbuc1 
-    lda #(mod((3+1-1)*6/2,2)<<2>>1^6|1)&1
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1&(byte) 1 [phi:main::@10->test#1] -- vbuz1=vbuc1 
+    lda #(((3+1-1)*6/2&2-1)<<2>>1^6|1)&1
     sta.z test.a
     jsr test
     jmp __breturn
@@ -1372,8 +1374,8 @@ main: {
     // [27] phi from main::@5 to test [phi:main::@5->test]
     // [27] phi (byte) test::i#11 = (byte) 5 [phi:main::@5->test#0] -- vbuxx=vbuc1 
     ldx #5
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2 [phi:main::@5->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1 [phi:main::@5->test#1] -- vbuz1=vbuc1 
+    lda #(3+1-1)*6/2&2-1
     sta.z test.a
     jsr test
     // [16] phi from main::@5 to main::@6 [phi:main::@5->main::@6]
@@ -1383,8 +1385,8 @@ main: {
     // [27] phi from main::@6 to test [phi:main::@6->test]
     // [27] phi (byte) test::i#11 = (byte) 6 [phi:main::@6->test#0] -- vbuxx=vbuc1 
     ldx #6
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2 [phi:main::@6->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)<<2
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2 [phi:main::@6->test#1] -- vbuz1=vbuc1 
+    lda #((3+1-1)*6/2&2-1)<<2
     sta.z test.a
     jsr test
     // [18] phi from main::@6 to main::@7 [phi:main::@6->main::@7]
@@ -1394,8 +1396,8 @@ main: {
     // [27] phi from main::@7 to test [phi:main::@7->test]
     // [27] phi (byte) test::i#11 = (byte) 7 [phi:main::@7->test#0] -- vbuxx=vbuc1 
     ldx #7
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1 [phi:main::@7->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)<<2>>1
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1 [phi:main::@7->test#1] -- vbuz1=vbuc1 
+    lda #((3+1-1)*6/2&2-1)<<2>>1
     sta.z test.a
     jsr test
     // [20] phi from main::@7 to main::@8 [phi:main::@7->main::@8]
@@ -1405,8 +1407,8 @@ main: {
     // [27] phi from main::@8 to test [phi:main::@8->test]
     // [27] phi (byte) test::i#11 = (byte) 8 [phi:main::@8->test#0] -- vbuxx=vbuc1 
     ldx #8
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6 [phi:main::@8->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)<<2>>1^6
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6 [phi:main::@8->test#1] -- vbuz1=vbuc1 
+    lda #((3+1-1)*6/2&2-1)<<2>>1^6
     sta.z test.a
     jsr test
     // [22] phi from main::@8 to main::@9 [phi:main::@8->main::@9]
@@ -1416,8 +1418,8 @@ main: {
     // [27] phi from main::@9 to test [phi:main::@9->test]
     // [27] phi (byte) test::i#11 = (byte) 9 [phi:main::@9->test#0] -- vbuxx=vbuc1 
     ldx #9
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1 [phi:main::@9->test#1] -- vbuz1=vbuc1 
-    lda #mod((3+1-1)*6/2,2)<<2>>1^6|1
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1 [phi:main::@9->test#1] -- vbuz1=vbuc1 
+    lda #((3+1-1)*6/2&2-1)<<2>>1^6|1
     sta.z test.a
     jsr test
     // [24] phi from main::@9 to main::@10 [phi:main::@9->main::@10]
@@ -1427,8 +1429,8 @@ main: {
     // [27] phi from main::@10 to test [phi:main::@10->test]
     // [27] phi (byte) test::i#11 = (byte) $a [phi:main::@10->test#0] -- vbuxx=vbuc1 
     ldx #$a
-    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2%(byte) 2<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1&(byte) 1 [phi:main::@10->test#1] -- vbuz1=vbuc1 
-    lda #(mod((3+1-1)*6/2,2)<<2>>1^6|1)&1
+    // [27] phi (byte) test::a#11 = (byte) 3+(byte) 1-(byte) 1*(byte) 6/(byte) 2&(byte) 2-(byte) 1<<(byte) 2>>(byte) 1^(byte) 6|(byte) 1&(byte) 1 [phi:main::@10->test#1] -- vbuz1=vbuc1 
+    lda #(((3+1-1)*6/2&2-1)<<2>>1^6|1)&1
     sta.z test.a
     jsr test
     // main::@return
diff --git a/src/test/ref/bitmap-plot-0.log b/src/test/ref/bitmap-plot-0.log
index dcc0ab688..847645460 100644
--- a/src/test/ref/bitmap-plot-0.log
+++ b/src/test/ref/bitmap-plot-0.log
@@ -2321,12 +2321,12 @@ Allocated (was zp[2]:24) zp[2]:8 [ bitmap_plot::plotter#0 bitmap_plot::plotter#1
 Allocated (was zp[2]:26) zp[2]:10 [ bitmap_plot::$1 ]
 Allocated (was zp[1]:33) zp[1]:12 [ bitmap_init::$7 main::y#2 main::y#1 ]
 Interrupt procedure irq clobbers ACNZ
-Removing interrupt register storage stx regx+1 in CHU154 entry interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage sty regy+1 in CHU154 entry interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage regx: in CHU163 [85] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage ldx #00 in CHU163 [85] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage regy: in CHU163 [85] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage ldy #00 in CHU163 [85] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage stx regx+1 in 154 entry interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage sty regy+1 in 154 entry interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage regx: in 163 [85] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage ldx #00 in 163 [85] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage regy: in 163 [85] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage ldy #00 in 163 [85] return  - exit interrupt(HARDWARE_CLOBBER)
 
 ASSEMBLER BEFORE OPTIMIZATION
   // File Comments
diff --git a/src/test/ref/bitmap-plot-1.log b/src/test/ref/bitmap-plot-1.log
index c68f7ac80..d5e582778 100644
--- a/src/test/ref/bitmap-plot-1.log
+++ b/src/test/ref/bitmap-plot-1.log
@@ -6119,12 +6119,12 @@ Allocated (was zp[4]:163) zp[4]:28 [ sin16s::$4 mul16u::mb#2 mul16u::mb#0 mul16u
 Allocated (was zp[2]:169) zp[2]:32 [ mulu16_sel::return#0 mulu16_sel::return#12 mulu16_sel::return#2 sin16s::x3_6#0 mulu16_sel::return#11 sin16s::x5#0 sin16s::x5_128#0 memset::str#3 memset::dst#2 memset::dst#4 memset::dst#1 main::idx_y#3 main::idx_y#10 main::idx_y#1 ]
 Allocated (was zp[2]:211) zp[2]:34 [ div32u16u::quotient_hi#0 sin16s::x1#0 ]
 Interrupt procedure irq clobbers ACNZ
-Removing interrupt register storage stx regx+1 in CHU422 entry interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage sty regy+1 in CHU422 entry interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage regx: in CHU431 [230] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage ldx #00 in CHU431 [230] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage regy: in CHU431 [230] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage ldy #00 in CHU431 [230] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage stx regx+1 in 422 entry interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage sty regy+1 in 422 entry interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage regx: in 431 [230] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage ldx #00 in 431 [230] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage regy: in 431 [230] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage ldy #00 in 431 [230] return  - exit interrupt(HARDWARE_CLOBBER)
 
 ASSEMBLER BEFORE OPTIMIZATION
   // File Comments
diff --git a/src/test/ref/bitmap-plot-2.log b/src/test/ref/bitmap-plot-2.log
index 09fda018f..b36c9751a 100644
--- a/src/test/ref/bitmap-plot-2.log
+++ b/src/test/ref/bitmap-plot-2.log
@@ -6413,12 +6413,12 @@ Allocated (was zp[4]:162) zp[4]:28 [ sin16s::$4 mul16u::mb#2 mul16u::mb#0 mul16u
 Allocated (was zp[2]:168) zp[2]:32 [ mulu16_sel::return#0 mulu16_sel::return#12 mulu16_sel::return#2 sin16s::x3_6#0 mulu16_sel::return#11 sin16s::x5#0 sin16s::x5_128#0 bitmap_init::yoffs#2 bitmap_init::yoffs#4 bitmap_init::yoffs#1 main::idx_y#3 main::idx_y#10 main::idx_y#1 ]
 Allocated (was zp[2]:210) zp[2]:34 [ div32u16u::quotient_hi#0 sin16s::x1#0 sin16s_gen2::$9 mul16s::$13 mul16s::$17 ]
 Interrupt procedure irq clobbers ACNZ
-Removing interrupt register storage stx regx+1 in CHU441 entry interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage sty regy+1 in CHU441 entry interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage regx: in CHU450 [239] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage ldx #00 in CHU450 [239] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage regy: in CHU450 [239] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage ldy #00 in CHU450 [239] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage stx regx+1 in 441 entry interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage sty regy+1 in 441 entry interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage regx: in 450 [239] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage ldx #00 in 450 [239] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage regy: in 450 [239] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage ldy #00 in 450 [239] return  - exit interrupt(HARDWARE_CLOBBER)
 
 ASSEMBLER BEFORE OPTIMIZATION
   // File Comments
diff --git a/src/test/ref/clobber-a-problem.log b/src/test/ref/clobber-a-problem.log
index 336b9092d..f4e1068a1 100644
--- a/src/test/ref/clobber-a-problem.log
+++ b/src/test/ref/clobber-a-problem.log
@@ -313,9 +313,9 @@ Attempting to uplift remaining variables inzp[1]:3 [ irq_raster_next ]
 Uplifting [] best 246 combination zp[1]:3 [ irq_raster_next ] 
 Allocated (was zp[1]:3) zp[1]:2 [ irq_raster_next ]
 Interrupt procedure irq clobbers AXCNZ
-Removing interrupt register storage sty regy+1 in CHU16 entry interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage regy: in CHU30 [16] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage ldy #00 in CHU30 [16] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage sty regy+1 in 16 entry interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage regy: in 30 [16] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage ldy #00 in 30 [16] return  - exit interrupt(HARDWARE_CLOBBER)
 
 ASSEMBLER BEFORE OPTIMIZATION
   // File Comments
diff --git a/src/test/ref/complex/tetris/test-sprites.log b/src/test/ref/complex/tetris/test-sprites.log
index 0e3d45278..502598257 100644
--- a/src/test/ref/complex/tetris/test-sprites.log
+++ b/src/test/ref/complex/tetris/test-sprites.log
@@ -2443,9 +2443,9 @@ Allocated (was zp[1]:13) zp[1]:7 [ irq_sprite_ptr ]
 Allocated (was zp[1]:14) zp[1]:8 [ irq_cnt ]
 Allocated (was zp[1]:21) zp[1]:9 [ sprites_irq::raster_sprite_gfx_modify ]
 Interrupt procedure sprites_irq clobbers AXCNZV
-Removing interrupt register storage sty regy+1 in CHU127 entry interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage regy: in CHU161 [97] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage ldy #00 in CHU161 [97] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage sty regy+1 in 127 entry interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage regy: in 161 [97] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage ldy #00 in 161 [97] return  - exit interrupt(HARDWARE_CLOBBER)
 
 ASSEMBLER BEFORE OPTIMIZATION
   // File Comments
diff --git a/src/test/ref/complex/tetris/tetris.log b/src/test/ref/complex/tetris/tetris.log
index cafe323d0..1c61d5999 100644
--- a/src/test/ref/complex/tetris/tetris.log
+++ b/src/test/ref/complex/tetris/tetris.log
@@ -16781,9 +16781,9 @@ Allocated (was zp[1]:193) zp[1]:45 [ keyboard_event_pressed::row_bits#0 play_spa
 Allocated (was zp[1]:198) zp[1]:46 [ keyboard_event_scan::row_scan#0 play_lock_current::i#1 play_collision::i#1 ]
 Allocated (was zp[1]:218) zp[1]:47 [ sprites_irq::raster_sprite_gfx_modify ]
 Interrupt procedure sprites_irq clobbers AXCNZV
-Removing interrupt register storage sty regy+1 in CHU1185 entry interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage regy: in CHU1219 [576] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage ldy #00 in CHU1219 [576] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage sty regy+1 in 1185 entry interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage regy: in 1219 [576] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage ldy #00 in 1219 [576] return  - exit interrupt(HARDWARE_CLOBBER)
 
 ASSEMBLER BEFORE OPTIMIZATION
   // File Comments
diff --git a/src/test/ref/double-indexing-arrays.asm b/src/test/ref/double-indexing-arrays.asm
index d796a2780..827f8e883 100644
--- a/src/test/ref/double-indexing-arrays.asm
+++ b/src/test/ref/double-indexing-arrays.asm
@@ -5,35 +5,35 @@
   .label SCREEN = $400
   .label COLS = $d800
 main: {
-    ldy #0
+    ldx #0
   __b1:
-    lda MAPDATA,y
-    sta SCREEN,y
-    ldx MAPDATA,y
-    lda COLORMAP1,x
-    sta COLS,y
-    lda MAPDATA+$c8,y
-    sta SCREEN+$c8,y
-    ldx MAPDATA+$c8,y
-    lda COLORMAP1,x
-    sta COLS+$c8,y
-    lda MAPDATA+$190,y
-    sta SCREEN+$190,y
-    ldx MAPDATA+$190,y
-    lda COLORMAP1,x
-    sta COLS+$190,y
-    lda MAPDATA+$258,y
-    sta SCREEN+$258,y
-    ldx MAPDATA+$258,y
-    lda COLORMAP2,x
-    sta COLS+$258,y
-    lda MAPDATA+$320,y
-    sta SCREEN+$320,y
-    ldx MAPDATA+$320,y
-    lda COLORMAP2,x
-    sta COLS+$320,y
-    iny
-    cpy #$c9
+    lda MAPDATA,x
+    sta SCREEN,x
+    ldy MAPDATA,x
+    lda COLORMAP1,y
+    sta COLS,x
+    lda MAPDATA+$c8,x
+    sta SCREEN+$c8,x
+    ldy MAPDATA+$c8,x
+    lda COLORMAP1,y
+    sta COLS+$c8,x
+    lda MAPDATA+$190,x
+    sta SCREEN+$190,x
+    ldy MAPDATA+$190,x
+    lda COLORMAP1,y
+    sta COLS+$190,x
+    lda MAPDATA+$258,x
+    sta SCREEN+$258,x
+    ldy MAPDATA+$258,x
+    lda COLORMAP2,y
+    sta COLS+$258,x
+    lda MAPDATA+$320,x
+    sta SCREEN+$320,x
+    ldy MAPDATA+$320,x
+    lda COLORMAP2,y
+    sta COLS+$320,x
+    inx
+    cpx #$c9
     bne __b1
     rts
 }
diff --git a/src/test/ref/double-indexing-arrays.log b/src/test/ref/double-indexing-arrays.log
index 91373a865..0833d4858 100644
--- a/src/test/ref/double-indexing-arrays.log
+++ b/src/test/ref/double-indexing-arrays.log
@@ -82,10 +82,10 @@ SYMBOL TABLE SSA
 (number~) main::$9
 (label) main::@1
 (label) main::@return
-(byte) main::x !reg byte y
-(byte) main::x#0 !reg byte y
-(byte) main::x#1 !reg byte y
-(byte) main::x#2 !reg byte y
+(byte) main::x
+(byte) main::x#0
+(byte) main::x#1
+(byte) main::x#2
 
 Adding number conversion cast (unumber) $c8 in (number~) main::$0 ← (number) $c8 + (byte) main::x#2
 Adding number conversion cast (unumber) main::$0 in (number~) main::$0 ← (unumber)(number) $c8 + (byte) main::x#2
@@ -301,14 +301,15 @@ main::@return: scope:[main]  from main::@1
 
 VARIABLE REGISTER WEIGHTS
 (void()) main()
-(byte) main::x !reg byte y
-(byte) main::x#1 !reg byte y 16.5
-(byte) main::x#2 !reg byte y 22.0
+(byte) main::x
+(byte) main::x#1 16.5
+(byte) main::x#2 22.0
 
 Initial phi equivalence classes
 [ main::x#2 main::x#1 ]
 Complete equivalence classes
 [ main::x#2 main::x#1 ]
+Allocated zp[1]:2 [ main::x#2 main::x#1 ]
 
 INITIAL ASM
 Target platform is c64basic / MOS6502X
@@ -339,10 +340,12 @@ __bend_from___b1:
 __bend:
   // main
 main: {
+    .label x = 2
     // [5] phi from main to main::@1 [phi:main->main::@1]
   __b1_from_main:
-    // [5] phi (byte) main::x#2 = (byte) 0 [phi:main->main::@1#0] -- vbuyy=vbuc1 
-    ldy #0
+    // [5] phi (byte) main::x#2 = (byte) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 
+    lda #0
+    sta.z x
     jmp __b1
     // [5] phi from main::@1 to main::@1 [phi:main::@1->main::@1]
   __b1_from___b1:
@@ -350,45 +353,56 @@ main: {
     jmp __b1
     // main::@1
   __b1:
-    // [6] *((const byte*) SCREEN + (byte) main::x#2) ← *((const byte*) MAPDATA + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
+    // [6] *((const byte*) SCREEN + (byte) main::x#2) ← *((const byte*) MAPDATA + (byte) main::x#2) -- pbuc1_derefidx_vbuz1=pbuc2_derefidx_vbuz1 
+    ldy.z x
     lda MAPDATA,y
     sta SCREEN,y
-    // [7] *((const byte*) COLS + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA,y
-    lda COLORMAP1,x
-    sta COLS,y
-    // [8] *((const byte*) SCREEN+(byte) $c8 + (byte) main::x#2) ← *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
+    // [7] *((const byte*) COLS + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA + (byte) main::x#2)) -- pbuc1_derefidx_vbuz1=pbuc2_derefidx_(pbuc3_derefidx_vbuz1) 
+    ldx.z x
+    ldy MAPDATA,x
+    lda COLORMAP1,y
+    sta COLS,x
+    // [8] *((const byte*) SCREEN+(byte) $c8 + (byte) main::x#2) ← *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2) -- pbuc1_derefidx_vbuz1=pbuc2_derefidx_vbuz1 
+    ldy.z x
     lda MAPDATA+$c8,y
     sta SCREEN+$c8,y
-    // [9] *((const byte*) COLS+(byte) $c8 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA+$c8,y
-    lda COLORMAP1,x
-    sta COLS+$c8,y
-    // [10] *((const byte*) SCREEN+(word) $190 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
+    // [9] *((const byte*) COLS+(byte) $c8 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2)) -- pbuc1_derefidx_vbuz1=pbuc2_derefidx_(pbuc3_derefidx_vbuz1) 
+    ldx.z x
+    ldy MAPDATA+$c8,x
+    lda COLORMAP1,y
+    sta COLS+$c8,x
+    // [10] *((const byte*) SCREEN+(word) $190 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2) -- pbuc1_derefidx_vbuz1=pbuc2_derefidx_vbuz1 
+    ldy.z x
     lda MAPDATA+$190,y
     sta SCREEN+$190,y
-    // [11] *((const byte*) COLS+(word) $190 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA+$190,y
-    lda COLORMAP1,x
-    sta COLS+$190,y
-    // [12] *((const byte*) SCREEN+(word) $258 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
+    // [11] *((const byte*) COLS+(word) $190 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2)) -- pbuc1_derefidx_vbuz1=pbuc2_derefidx_(pbuc3_derefidx_vbuz1) 
+    ldx.z x
+    ldy MAPDATA+$190,x
+    lda COLORMAP1,y
+    sta COLS+$190,x
+    // [12] *((const byte*) SCREEN+(word) $258 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2) -- pbuc1_derefidx_vbuz1=pbuc2_derefidx_vbuz1 
+    ldy.z x
     lda MAPDATA+$258,y
     sta SCREEN+$258,y
-    // [13] *((const byte*) COLS+(word) $258 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA+$258,y
-    lda COLORMAP2,x
-    sta COLS+$258,y
-    // [14] *((const byte*) SCREEN+(word) $320 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
+    // [13] *((const byte*) COLS+(word) $258 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2)) -- pbuc1_derefidx_vbuz1=pbuc2_derefidx_(pbuc3_derefidx_vbuz1) 
+    ldx.z x
+    ldy MAPDATA+$258,x
+    lda COLORMAP2,y
+    sta COLS+$258,x
+    // [14] *((const byte*) SCREEN+(word) $320 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2) -- pbuc1_derefidx_vbuz1=pbuc2_derefidx_vbuz1 
+    ldy.z x
     lda MAPDATA+$320,y
     sta SCREEN+$320,y
-    // [15] *((const byte*) COLS+(word) $320 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA+$320,y
-    lda COLORMAP2,x
-    sta COLS+$320,y
-    // [16] (byte) main::x#1 ← ++ (byte) main::x#2 -- vbuyy=_inc_vbuyy 
-    iny
-    // [17] if((byte) main::x#1!=(byte) $c9) goto main::@1 -- vbuyy_neq_vbuc1_then_la1 
-    cpy #$c9
+    // [15] *((const byte*) COLS+(word) $320 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2)) -- pbuc1_derefidx_vbuz1=pbuc2_derefidx_(pbuc3_derefidx_vbuz1) 
+    ldx.z x
+    ldy MAPDATA+$320,x
+    lda COLORMAP2,y
+    sta COLS+$320,x
+    // [16] (byte) main::x#1 ← ++ (byte) main::x#2 -- vbuz1=_inc_vbuz1 
+    inc.z x
+    // [17] if((byte) main::x#1!=(byte) $c9) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 
+    lda #$c9
+    cmp.z x
     bne __b1_from___b1
     jmp __breturn
     // main::@return
@@ -403,23 +417,33 @@ main: {
 
 REGISTER UPLIFT POTENTIAL REGISTERS
 Statement [6] *((const byte*) SCREEN + (byte) main::x#2) ← *((const byte*) MAPDATA + (byte) main::x#2) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
-Statement [7] *((const byte*) COLS + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a reg byte x 
+Removing always clobbered register reg byte a as potential for zp[1]:2 [ main::x#2 main::x#1 ]
+Statement [7] *((const byte*) COLS + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
 Statement [8] *((const byte*) SCREEN+(byte) $c8 + (byte) main::x#2) ← *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
-Statement [9] *((const byte*) COLS+(byte) $c8 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a reg byte x 
+Statement [9] *((const byte*) COLS+(byte) $c8 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
 Statement [10] *((const byte*) SCREEN+(word) $190 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
-Statement [11] *((const byte*) COLS+(word) $190 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a reg byte x 
+Statement [11] *((const byte*) COLS+(word) $190 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
 Statement [12] *((const byte*) SCREEN+(word) $258 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
-Statement [13] *((const byte*) COLS+(word) $258 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a reg byte x 
+Statement [13] *((const byte*) COLS+(word) $258 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
 Statement [14] *((const byte*) SCREEN+(word) $320 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
-Statement [15] *((const byte*) COLS+(word) $320 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a reg byte x 
-Statement [16] (byte) main::x#1 ← ++ (byte) main::x#2 [ main::x#1 ] ( main:2 [ main::x#1 ] ) always clobbers reg byte y 
-Potential registers reg byte y [ main::x#2 main::x#1 ] : reg byte y , 
+Statement [15] *((const byte*) COLS+(word) $320 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
+Statement [6] *((const byte*) SCREEN + (byte) main::x#2) ← *((const byte*) MAPDATA + (byte) main::x#2) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
+Statement [7] *((const byte*) COLS + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
+Statement [8] *((const byte*) SCREEN+(byte) $c8 + (byte) main::x#2) ← *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
+Statement [9] *((const byte*) COLS+(byte) $c8 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
+Statement [10] *((const byte*) SCREEN+(word) $190 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
+Statement [11] *((const byte*) COLS+(word) $190 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
+Statement [12] *((const byte*) SCREEN+(word) $258 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
+Statement [13] *((const byte*) COLS+(word) $258 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
+Statement [14] *((const byte*) SCREEN+(word) $320 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
+Statement [15] *((const byte*) COLS+(word) $320 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2)) [ main::x#2 ] ( main:2 [ main::x#2 ] ) always clobbers reg byte a 
+Potential registers zp[1]:2 [ main::x#2 main::x#1 ] : zp[1]:2 , reg byte x , reg byte y , 
 
 REGISTER UPLIFT SCOPES
-Uplift Scope [main] 38.5: reg byte y [ main::x#2 main::x#1 ] 
+Uplift Scope [main] 38.5: zp[1]:2 [ main::x#2 main::x#1 ] 
 Uplift Scope [] 
 
-Uplifting [main] best 1368 combination reg byte y [ main::x#2 main::x#1 ] 
+Uplifting [main] best 1368 combination reg byte x [ main::x#2 main::x#1 ] 
 Uplifting [] best 1368 combination 
 
 ASSEMBLER BEFORE OPTIMIZATION
@@ -452,8 +476,8 @@ __bend:
 main: {
     // [5] phi from main to main::@1 [phi:main->main::@1]
   __b1_from_main:
-    // [5] phi (byte) main::x#2 = (byte) 0 [phi:main->main::@1#0] -- vbuyy=vbuc1 
-    ldy #0
+    // [5] phi (byte) main::x#2 = (byte) 0 [phi:main->main::@1#0] -- vbuxx=vbuc1 
+    ldx #0
     jmp __b1
     // [5] phi from main::@1 to main::@1 [phi:main::@1->main::@1]
   __b1_from___b1:
@@ -461,45 +485,45 @@ main: {
     jmp __b1
     // main::@1
   __b1:
-    // [6] *((const byte*) SCREEN + (byte) main::x#2) ← *((const byte*) MAPDATA + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
-    lda MAPDATA,y
-    sta SCREEN,y
-    // [7] *((const byte*) COLS + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA,y
-    lda COLORMAP1,x
-    sta COLS,y
-    // [8] *((const byte*) SCREEN+(byte) $c8 + (byte) main::x#2) ← *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
-    lda MAPDATA+$c8,y
-    sta SCREEN+$c8,y
-    // [9] *((const byte*) COLS+(byte) $c8 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA+$c8,y
-    lda COLORMAP1,x
-    sta COLS+$c8,y
-    // [10] *((const byte*) SCREEN+(word) $190 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
-    lda MAPDATA+$190,y
-    sta SCREEN+$190,y
-    // [11] *((const byte*) COLS+(word) $190 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA+$190,y
-    lda COLORMAP1,x
-    sta COLS+$190,y
-    // [12] *((const byte*) SCREEN+(word) $258 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
-    lda MAPDATA+$258,y
-    sta SCREEN+$258,y
-    // [13] *((const byte*) COLS+(word) $258 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA+$258,y
-    lda COLORMAP2,x
-    sta COLS+$258,y
-    // [14] *((const byte*) SCREEN+(word) $320 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
-    lda MAPDATA+$320,y
-    sta SCREEN+$320,y
-    // [15] *((const byte*) COLS+(word) $320 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA+$320,y
-    lda COLORMAP2,x
-    sta COLS+$320,y
-    // [16] (byte) main::x#1 ← ++ (byte) main::x#2 -- vbuyy=_inc_vbuyy 
-    iny
-    // [17] if((byte) main::x#1!=(byte) $c9) goto main::@1 -- vbuyy_neq_vbuc1_then_la1 
-    cpy #$c9
+    // [6] *((const byte*) SCREEN + (byte) main::x#2) ← *((const byte*) MAPDATA + (byte) main::x#2) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_vbuxx 
+    lda MAPDATA,x
+    sta SCREEN,x
+    // [7] *((const byte*) COLS + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA + (byte) main::x#2)) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_(pbuc3_derefidx_vbuxx) 
+    ldy MAPDATA,x
+    lda COLORMAP1,y
+    sta COLS,x
+    // [8] *((const byte*) SCREEN+(byte) $c8 + (byte) main::x#2) ← *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_vbuxx 
+    lda MAPDATA+$c8,x
+    sta SCREEN+$c8,x
+    // [9] *((const byte*) COLS+(byte) $c8 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2)) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_(pbuc3_derefidx_vbuxx) 
+    ldy MAPDATA+$c8,x
+    lda COLORMAP1,y
+    sta COLS+$c8,x
+    // [10] *((const byte*) SCREEN+(word) $190 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_vbuxx 
+    lda MAPDATA+$190,x
+    sta SCREEN+$190,x
+    // [11] *((const byte*) COLS+(word) $190 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2)) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_(pbuc3_derefidx_vbuxx) 
+    ldy MAPDATA+$190,x
+    lda COLORMAP1,y
+    sta COLS+$190,x
+    // [12] *((const byte*) SCREEN+(word) $258 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_vbuxx 
+    lda MAPDATA+$258,x
+    sta SCREEN+$258,x
+    // [13] *((const byte*) COLS+(word) $258 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2)) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_(pbuc3_derefidx_vbuxx) 
+    ldy MAPDATA+$258,x
+    lda COLORMAP2,y
+    sta COLS+$258,x
+    // [14] *((const byte*) SCREEN+(word) $320 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_vbuxx 
+    lda MAPDATA+$320,x
+    sta SCREEN+$320,x
+    // [15] *((const byte*) COLS+(word) $320 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2)) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_(pbuc3_derefidx_vbuxx) 
+    ldy MAPDATA+$320,x
+    lda COLORMAP2,y
+    sta COLS+$320,x
+    // [16] (byte) main::x#1 ← ++ (byte) main::x#2 -- vbuxx=_inc_vbuxx 
+    inx
+    // [17] if((byte) main::x#1!=(byte) $c9) goto main::@1 -- vbuxx_neq_vbuc1_then_la1 
+    cpx #$c9
     bne __b1_from___b1
     jmp __breturn
     // main::@return
@@ -550,11 +574,11 @@ FINAL SYMBOL TABLE
 (void()) main()
 (label) main::@1
 (label) main::@return
-(byte) main::x !reg byte y
-(byte) main::x#1 !reg byte y 16.5
-(byte) main::x#2 !reg byte y 22.0
+(byte) main::x
+(byte) main::x#1 reg byte x 16.5
+(byte) main::x#2 reg byte x 22.0
 
-reg byte y [ main::x#2 main::x#1 ]
+reg byte x [ main::x#2 main::x#1 ]
 
 
 FINAL ASSEMBLER
@@ -579,62 +603,62 @@ Score: 1266
   // main
 main: {
     // [5] phi from main to main::@1 [phi:main->main::@1]
-    // [5] phi (byte) main::x#2 = (byte) 0 [phi:main->main::@1#0] -- vbuyy=vbuc1 
-    ldy #0
+    // [5] phi (byte) main::x#2 = (byte) 0 [phi:main->main::@1#0] -- vbuxx=vbuc1 
+    ldx #0
     // [5] phi from main::@1 to main::@1 [phi:main::@1->main::@1]
     // [5] phi (byte) main::x#2 = (byte) main::x#1 [phi:main::@1->main::@1#0] -- register_copy 
     // main::@1
   __b1:
     // SCREEN[x] = MAPDATA[x]
-    // [6] *((const byte*) SCREEN + (byte) main::x#2) ← *((const byte*) MAPDATA + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
-    lda MAPDATA,y
-    sta SCREEN,y
+    // [6] *((const byte*) SCREEN + (byte) main::x#2) ← *((const byte*) MAPDATA + (byte) main::x#2) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_vbuxx 
+    lda MAPDATA,x
+    sta SCREEN,x
     // COLS[x] = COLORMAP1[MAPDATA[x]]
-    // [7] *((const byte*) COLS + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA,y
-    lda COLORMAP1,x
-    sta COLS,y
+    // [7] *((const byte*) COLS + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA + (byte) main::x#2)) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_(pbuc3_derefidx_vbuxx) 
+    ldy MAPDATA,x
+    lda COLORMAP1,y
+    sta COLS,x
     // SCREEN[200+x] = MAPDATA[200+x]
-    // [8] *((const byte*) SCREEN+(byte) $c8 + (byte) main::x#2) ← *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
-    lda MAPDATA+$c8,y
-    sta SCREEN+$c8,y
+    // [8] *((const byte*) SCREEN+(byte) $c8 + (byte) main::x#2) ← *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_vbuxx 
+    lda MAPDATA+$c8,x
+    sta SCREEN+$c8,x
     // COLS[200+x] = COLORMAP1[MAPDATA[200+x]]
-    // [9] *((const byte*) COLS+(byte) $c8 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA+$c8,y
-    lda COLORMAP1,x
-    sta COLS+$c8,y
+    // [9] *((const byte*) COLS+(byte) $c8 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(byte) $c8 + (byte) main::x#2)) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_(pbuc3_derefidx_vbuxx) 
+    ldy MAPDATA+$c8,x
+    lda COLORMAP1,y
+    sta COLS+$c8,x
     // SCREEN[400+x] = MAPDATA[400+x]
-    // [10] *((const byte*) SCREEN+(word) $190 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
-    lda MAPDATA+$190,y
-    sta SCREEN+$190,y
+    // [10] *((const byte*) SCREEN+(word) $190 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_vbuxx 
+    lda MAPDATA+$190,x
+    sta SCREEN+$190,x
     // COLS[400+x] = COLORMAP1[MAPDATA[400+x]]
-    // [11] *((const byte*) COLS+(word) $190 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA+$190,y
-    lda COLORMAP1,x
-    sta COLS+$190,y
+    // [11] *((const byte*) COLS+(word) $190 + (byte) main::x#2) ← *((const byte*) COLORMAP1 + *((const byte*) MAPDATA+(word) $190 + (byte) main::x#2)) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_(pbuc3_derefidx_vbuxx) 
+    ldy MAPDATA+$190,x
+    lda COLORMAP1,y
+    sta COLS+$190,x
     // SCREEN[600+x] = MAPDATA[600+x]
-    // [12] *((const byte*) SCREEN+(word) $258 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
-    lda MAPDATA+$258,y
-    sta SCREEN+$258,y
+    // [12] *((const byte*) SCREEN+(word) $258 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_vbuxx 
+    lda MAPDATA+$258,x
+    sta SCREEN+$258,x
     // COLS[600+x] = COLORMAP2[MAPDATA[600+x]]
-    // [13] *((const byte*) COLS+(word) $258 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA+$258,y
-    lda COLORMAP2,x
-    sta COLS+$258,y
+    // [13] *((const byte*) COLS+(word) $258 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $258 + (byte) main::x#2)) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_(pbuc3_derefidx_vbuxx) 
+    ldy MAPDATA+$258,x
+    lda COLORMAP2,y
+    sta COLS+$258,x
     // SCREEN[800+x] = MAPDATA[800+x]
-    // [14] *((const byte*) SCREEN+(word) $320 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_vbuyy 
-    lda MAPDATA+$320,y
-    sta SCREEN+$320,y
+    // [14] *((const byte*) SCREEN+(word) $320 + (byte) main::x#2) ← *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_vbuxx 
+    lda MAPDATA+$320,x
+    sta SCREEN+$320,x
     // COLS[800+x] = COLORMAP2[MAPDATA[800+x]]
-    // [15] *((const byte*) COLS+(word) $320 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2)) -- pbuc1_derefidx_vbuyy=pbuc2_derefidx_(pbuc3_derefidx_vbuyy) 
-    ldx MAPDATA+$320,y
-    lda COLORMAP2,x
-    sta COLS+$320,y
-    // for (byte register(y) x: 0..200)
-    // [16] (byte) main::x#1 ← ++ (byte) main::x#2 -- vbuyy=_inc_vbuyy 
-    iny
-    // [17] if((byte) main::x#1!=(byte) $c9) goto main::@1 -- vbuyy_neq_vbuc1_then_la1 
-    cpy #$c9
+    // [15] *((const byte*) COLS+(word) $320 + (byte) main::x#2) ← *((const byte*) COLORMAP2 + *((const byte*) MAPDATA+(word) $320 + (byte) main::x#2)) -- pbuc1_derefidx_vbuxx=pbuc2_derefidx_(pbuc3_derefidx_vbuxx) 
+    ldy MAPDATA+$320,x
+    lda COLORMAP2,y
+    sta COLS+$320,x
+    // for (byte x: 0..200)
+    // [16] (byte) main::x#1 ← ++ (byte) main::x#2 -- vbuxx=_inc_vbuxx 
+    inx
+    // [17] if((byte) main::x#1!=(byte) $c9) goto main::@1 -- vbuxx_neq_vbuc1_then_la1 
+    cpx #$c9
     bne __b1
     // main::@return
     // }
diff --git a/src/test/ref/double-indexing-arrays.sym b/src/test/ref/double-indexing-arrays.sym
index 02a5295d4..8965baa2f 100644
--- a/src/test/ref/double-indexing-arrays.sym
+++ b/src/test/ref/double-indexing-arrays.sym
@@ -9,8 +9,8 @@
 (void()) main()
 (label) main::@1
 (label) main::@return
-(byte) main::x !reg byte y
-(byte) main::x#1 !reg byte y 16.5
-(byte) main::x#2 !reg byte y 22.0
+(byte) main::x
+(byte) main::x#1 reg byte x 16.5
+(byte) main::x#2 reg byte x 22.0
 
-reg byte y [ main::x#2 main::x#1 ]
+reg byte x [ main::x#2 main::x#1 ]
diff --git a/src/test/ref/irq-hardware-clobber-jsr.log b/src/test/ref/irq-hardware-clobber-jsr.log
index 4205040a5..335658b6e 100644
--- a/src/test/ref/irq-hardware-clobber-jsr.log
+++ b/src/test/ref/irq-hardware-clobber-jsr.log
@@ -354,12 +354,12 @@ Uplifting [irq] best 329 combination
 Uplifting [do_irq] best 329 combination 
 Uplifting [] best 329 combination 
 Interrupt procedure irq clobbers ANZ
-Removing interrupt register storage stx regx+1 in CHU22 entry interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage sty regy+1 in CHU22 entry interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage regx: in CHU25 [16] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage ldx #00 in CHU25 [16] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage regy: in CHU25 [16] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage ldy #00 in CHU25 [16] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage stx regx+1 in 22 entry interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage sty regy+1 in 22 entry interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage regx: in 25 [16] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage ldx #00 in 25 [16] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage regy: in 25 [16] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage ldy #00 in 25 [16] return  - exit interrupt(HARDWARE_CLOBBER)
 
 ASSEMBLER BEFORE OPTIMIZATION
   // File Comments
diff --git a/src/test/ref/irq-hardware-clobber.log b/src/test/ref/irq-hardware-clobber.log
index 218bc1bba..0667a9f33 100644
--- a/src/test/ref/irq-hardware-clobber.log
+++ b/src/test/ref/irq-hardware-clobber.log
@@ -302,12 +302,12 @@ Uplifting [main] best 314 combination
 Uplifting [irq] best 314 combination 
 Uplifting [] best 314 combination 
 Interrupt procedure irq clobbers ANZ
-Removing interrupt register storage stx regx+1 in CHU22 entry interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage sty regy+1 in CHU22 entry interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage regx: in CHU27 [17] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage ldx #00 in CHU27 [17] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage regy: in CHU27 [17] return  - exit interrupt(HARDWARE_CLOBBER)
-Removing interrupt register storage ldy #00 in CHU27 [17] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage stx regx+1 in 22 entry interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage sty regy+1 in 22 entry interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage regx: in 27 [17] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage ldx #00 in 27 [17] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage regy: in 27 [17] return  - exit interrupt(HARDWARE_CLOBBER)
+Removing interrupt register storage ldy #00 in 27 [17] return  - exit interrupt(HARDWARE_CLOBBER)
 
 ASSEMBLER BEFORE OPTIMIZATION
   // File Comments