Working on outputting variable labels in ASM. Moving register allocation & constant values into symbol table.

2024-11-14 23:04:57 +00:00 · 2017-08-20 21:09:03 +02:00 · 2017-08-20 21:09:03 +02:00 · 2707bd5861
commit 2707bd5861
parent df631667a0
32 changed files with 2113 additions and 478 deletions
--- a/src/main/java/dk/camelot64/kickc/Compiler.java
+++ b/src/main/java/dk/camelot64/kickc/Compiler.java
@ -21,6 +21,8 @@ public class Compiler {
         KickCParser.FileContext file = pass0ParseInput(input, log);
         Program program = pass1GenerateSSA(file, log);
         pass2OptimizeSSA(program);
+         log.append("FINAL SYMBOL TABLE");
+         log.append(program.getScope().getSymbolTableContents(program));
         pass3Analysis(program);
         pass4RegisterAllocation(program);
         pass5GenerateAndOptimizeAsm(program);
@ -110,6 +112,10 @@ public class Compiler {
      program.setGraph(pass1ProcedureCallsReturnValue.generate());
      log.append("CONTROL FLOW GRAPH WITH ASSIGNMENT CALL & RETURN");
      log.append(program.getGraph().toString(program));
+
+      log.append("INITIAL SSA SYMBOL TABLE");
+      log.append(program.getScope().getSymbolTableContents(program));
+
      return program;
   }

@ -204,7 +210,7 @@ public class Compiler {
   private void pass4RegisterAllocation(Program program) {

      new Pass4ZeroPageAllocation(program).allocate();
-      new Pass4RegistersFinalize(program).allocate(false);
+      new Pass4RegistersFinalize(program).allocate(true);

      // Initial Code generation
      new Pass4CodeGeneration(program).generate();
--- a/src/main/java/dk/camelot64/kickc/TODO.txt
+++ b/src/main/java/dk/camelot64/kickc/TODO.txt
@ -1,7 +1,8 @@
 Features
 - Move the main code into a main() function, and disallow code outside functions. The main function per default has no parameters and exits with RTS.
- Add a for loop for(init;condition;increment) {stmt} -> { init; do { stmt; increment } while (condition) }
- Add for loop for(byte i: 1..100) { } and for(byte i : 100..0) {}  (plus maybe .+. and .-. to make the inc/dec unambiguous)
+- Improve locality of block sequence for if(cond) { stmt1; } else { stmt2; } to if(!cond) goto @else stmt1; jmp @end; @else: stmt2; @end:
+- Optimize if/else by swapping if & else if cond is easier to evaluate than !cond.
+- Add literal char syntax ( 'c' == (byte) 3 )
 - Add signed bytes
 - Add signed words
 - Add Fixed Point number types fixed[8.8], fixed[16.8] - maybe even fixed[24.4]
@ -22,16 +23,23 @@ Features
 + Create a proper main function for the compiler
 + Add ++/-- incrementing/decrementing operators.
 + Optimize if's without else if(expr) { stmt; } -> $1=!expr; if($1) goto @1; stmt; @1:
+ Add a for loop for(init;condition;increment) {stmt} -> { init; do { stmt; increment } while (condition) }
+ Add for loop for(byte i: 1..100) { } and for(byte i : 100..0) {}  (plus maybe .+. and .-. to make the inc/dec unambiguous)

 Assembler Improvements
 - Make generated ASM human readable.
  + Use hex-numbers
  - add labels for constants and zp-variables.
-+ Eliminate unnecessary labels in ASM
- Eliminate CPX from DEX, CPX #0, BNE la1
- Eliminate LDA from DEC $2, LDA $2, BNE la1
- Eliminate LDA from STA $11, LDA $11
+- Better ASM static value analysis
+  - Not just constants - but also other values (value of var, value of var1[var2], value of var+4 etc.)
+  - Also analyze back/forward through block entry/exit
+  - Also analyze value of flags (eg. N=N(var1))
+- Eliminate CPX from DEX, CPX #0, BNE la1 (using ASM static value analysis for N flag - it might be worth annotating CPX with the fact that only the N-flag is relevant - or creating a special instruction for setting the N-flag)
+- Eliminate LDA from DEC $2, LDA $2, BNE la1 (using ASM static value analysis for N flag - it might be worth annotating LDA $2 with the fact that only the N-flag is relevant - or creating a special instruction for setting the N-flag)
+- Eliminate LDA from STA $11, LDA $11 (using ASM static value analysis of A-register)
 - Optimize by allowing resequencing of ASM (statements and phi assignments) in a final phase.
+- ASM loop analysis: If all usages of a register has the same value move the assignment out of the loop (if the assignment is simple enough).
+ Eliminate unnecessary labels in ASM

 Known Problems
 + Procedures that modify variables outside their scope does not work. Outer vars must be transfered in/out like parameters/return values to get it working.
@ -45,7 +53,11 @@ Register Allocation
  - Optimize by finding optimal sequence for multiple phi assignments in entry-segments.
  - Avoid clobbering alive vars
 - Maybe support several fragments for the same operation with different cost and clobbering profiles.
- Add memory registers (if we need to free some ZP)
+- Add memory registers (if we need to free some ZP).
+- Implement fast combination elimination based on live ranges (skipping the ASM-code.)
+  - Improve combination testing by finding live range overlaps and not creating combinations that would create an overlap conflict.
+  - Combinations should be created in a tree-structure instead of just doing all combinations
+  - Example: For equivalence classes a, b, c if a&c have overlapping live ranges they can never have the same register. Therefore the combination iterator should not create combinations where C has the same register as a.
 + Limit number of combinations tested
 + Equivalences not tested through combinaitons should be tested individually afterwards.
 + Matrix Phi operation (instead of separate statements)
--- a/src/main/java/dk/camelot64/kickc/icl/RegisterAllocation.java
+++ b/src/main/java/dk/camelot64/kickc/icl/RegisterAllocation.java
@ -47,8 +47,12 @@ public class RegisterAllocation {
   /** A zero page address used as a register for a single byte variable. */
   public static class RegisterZpByte implements Register {

+      /** The ZP address used for the byte. */
      private int zp;

+      /** The name used as a label for the register in the ASM code. */
+      private String name;
+
      public RegisterZpByte(int zp) {
         this.zp = zp;
      }
--- a/src/main/java/dk/camelot64/kickc/icl/SymbolTypeArray.java
+++ b/src/main/java/dk/camelot64/kickc/icl/SymbolTypeArray.java
@ -6,7 +6,8 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 /** A fixed size array of another type */
 public class SymbolTypeArray extends SymbolTypePointer {

-   private int size;
+   /** The fixed size of the array. Can by null, if the type is not known yet. (It will be constant before the compilation is done) */
+   private Integer size;

   @JsonCreator
   public SymbolTypeArray(
@ -16,40 +17,39 @@ public class SymbolTypeArray extends SymbolTypePointer {
      this.size = size;
   }

+   public SymbolTypeArray(SymbolType elementType) {
+      super(elementType);
+      this.size = null;
+   }
+
   public int getSize() {
      return size;
   }

-   public void setSize(int size) {
+   public void setSize(Integer size) {
      this.size = size;
   }

   @Override
   public String getTypeName() {
-      return getElementType().getTypeName()+"["+size+"]";
+      return getElementType().getTypeName()+"["+(size==null?"":size)+"]";
   }

   @Override
   public boolean equals(Object o) {
-      if (this == o) {
-         return true;
-      }
-      if (o == null || getClass() != o.getClass()) {
-         return false;
-      }
-      if (!super.equals(o)) {
-         return false;
-      }
+      if (this == o) return true;
+      if (o == null || getClass() != o.getClass()) return false;
+      if (!super.equals(o)) return false;

      SymbolTypeArray that = (SymbolTypeArray) o;

-      return size == that.size;
+      return size != null ? size.equals(that.size) : that.size == null;
   }

   @Override
   public int hashCode() {
      int result = super.hashCode();
-      result = 31 * result + size;
+      result = 31 * result + (size != null ? size.hashCode() : 0);
      return result;
   }
 }
--- a/src/main/java/dk/camelot64/kickc/icl/Variable.java
+++ b/src/main/java/dk/camelot64/kickc/icl/Variable.java
@ -2,32 +2,28 @@ package dk.camelot64.kickc.icl;

 import com.fasterxml.jackson.annotation.JsonIgnore;

-/**
- * A Symbol (variable, jump label, etc.)
- */
+/** A Variable (or a Constant) */
 public abstract class Variable implements Symbol {

-   /**
-    * The name of the symbol.
-    */
+   /** The name of the variable. */
   private String name;

-   /**
-    * Scope
-    */
+   /** The scope containing the variable */
   @JsonIgnore
   private Scope scope;

-   /**
-    * The type of the symbol. VAR means tha type is unknown, and has not been inferred yet.
-    */
+   /** The type of the variable. VAR means tha type is unknown, and has not been inferred yet. */
   private SymbolType type;

-   /**
-    * true if the symbol type is infered (not declared)
-    */
+   /** true if the symbol type is infered (not declared) */
   private boolean inferredType;

+   /** If the variable is assigned to an ASM register, this contains the register. If null the variable has no no allocation (yet). Constants are never assigned to registers. */
+   private RegisterAllocation.Register allocation;
+
+   /** If the variable is a constant this is the constant value. If null the variable is not considered constant.*/
+   private Constant constant;
+
   public Variable(String name, Scope scope, SymbolType type) {
      this.name = name;
      this.scope = scope;
@ -74,6 +70,26 @@ public abstract class Variable implements Symbol {
      this.name = name;
   }

+   public String getName() {
+      return name;
+   }
+
+   public RegisterAllocation.Register getAllocation() {
+      return allocation;
+   }
+
+   public void setAllocation(RegisterAllocation.Register allocation) {
+      this.allocation = allocation;
+   }
+
+   public Constant getConstant() {
+      return constant;
+   }
+
+   public void setConstant(Constant constant) {
+      this.constant = constant;
+   }
+
   @JsonIgnore
   public abstract boolean isVersioned();

@ -86,16 +102,21 @@ public abstract class Variable implements Symbol {
      if (o == null || getClass() != o.getClass()) return false;
      Variable variable = (Variable) o;
      if (inferredType != variable.inferredType) return false;
-      if (!name.equals(variable.name)) return false;
-      if (!getFullName().equals(variable.getFullName())) return false;
-      return type.equals(variable.type);
+      if (name != null ? !name.equals(variable.name) : variable.name != null) return false;
+      if (scope != null ? !scope.equals(variable.scope) : variable.scope != null) return false;
+      if (type != null ? !type.equals(variable.type) : variable.type != null) return false;
+      if (allocation != null ? !allocation.equals(variable.allocation) : variable.allocation != null) return false;
+      return constant != null ? constant.equals(variable.constant) : variable.constant == null;
   }

   @Override
   public int hashCode() {
-      int result = getFullName().hashCode();
-      result = 31 * result + type.hashCode();
+      int result = name != null ? name.hashCode() : 0;
+      result = 31 * result + (scope != null ? scope.hashCode() : 0);
+      result = 31 * result + (type != null ? type.hashCode() : 0);
      result = 31 * result + (inferredType ? 1 : 0);
+      result = 31 * result + (allocation != null ? allocation.hashCode() : 0);
+      result = 31 * result + (constant != null ? constant.hashCode() : 0);
      return result;
   }

--- a/src/main/java/dk/camelot64/kickc/passes/Pass1GenerateStatementSequence.java
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass1GenerateStatementSequence.java
@ -414,11 +414,15 @@ public class Pass1GenerateStatementSequence extends KickCBaseVisitor<Object> {
   @Override
   public SymbolType visitTypeArray(KickCParser.TypeArrayContext ctx) {
      SymbolType elementType = (SymbolType) visit(ctx.typeDecl());
-      Constant size = ParseTreeConstantEvaluator.evaluate(ctx.expr());
-      if (size instanceof ConstantInteger) {
-         return new SymbolTypeArray(elementType, ((ConstantInteger) size).getNumber());
+      if(ctx.expr()!=null) {
+         Constant size = ParseTreeConstantEvaluator.evaluate(ctx.expr());
+         if (size instanceof ConstantInteger) {
+            return new SymbolTypeArray(elementType, ((ConstantInteger) size).getNumber());
+         } else {
+            throw new RuntimeException("Array size not a constant integer " + ctx.getText());
+         }
      } else {
-         throw new RuntimeException("Array size not a constant integer " + ctx.getText());
+         return new SymbolTypeArray(elementType);
      }
   }

--- a/src/main/java/dk/camelot64/kickc/passes/Pass3CustomRegisters.java
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass3CustomRegisters.java
@ -1,142 +0,0 @@
-package dk.camelot64.kickc.passes;
-
-import dk.camelot64.kickc.icl.*;
-
-/**
- * Register Allocation for variables
- */
-public class Pass3CustomRegisters {
-
-
-   private Program program;
-
-   public Pass3CustomRegisters(Program program) {
-      this.program = program;
-   }
-
-   public void allocate() {
-      RegisterAllocation allocation = program.getAllocation();
-
-      // Register allocation for loopnest.kc
-      allocation.setRegister(new VariableRef("nest2::j#2"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("nest2::j#1"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("nest2::i#2"), RegisterAllocation.getRegisterY());
-      allocation.setRegister(new VariableRef("nest2::i#1"), RegisterAllocation.getRegisterY());
-
-
-      // Register allocation for fibmem.kc
-      /*
-      allocation.setRegister(new VariableRef("i#1"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("i#2"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("$1"), new RegisterAllocation.RegisterAByte());
-      allocation.setRegister(new VariableRef("$3"), new RegisterAllocation.RegisterALUByte());
-      allocation.setRegister(new VariableRef("$4"), new RegisterAllocation.RegisterAByte());
-      */
-
-      // Registers for postinc.kc
-      /*
-      allocation.setRegister(new VariableRef("c#0"), RegisterAllocation.getRegisterA());
-      allocation.setRegister(new VariableRef("c#1"), RegisterAllocation.getRegisterA());
-      allocation.setRegister(new VariableRef("c#2"), RegisterAllocation.getRegisterA());
-      allocation.setRegister(new VariableRef("b#0"), new RegisterAllocation.RegisterZpByte(102));
-      allocation.setRegister(new VariableRef("b#1"), new RegisterAllocation.RegisterZpByte(102));
-      allocation.setRegister(new VariableRef("b#2"), new RegisterAllocation.RegisterZpByte(102));
-      allocation.setRegister(new VariableRef("$1"), new RegisterAllocation.RegisterZpByte(101));
-      allocation.setRegister(new VariableRef("a#0"), new RegisterAllocation.RegisterZpByte(103));
-      allocation.setRegister(new VariableRef("a#1"), new RegisterAllocation.RegisterZpByte(103));
-      allocation.setRegister(new VariableRef("a#2"), new RegisterAllocation.RegisterZpByte(103));
-      allocation.setRegister(new VariableRef("$0"), RegisterAllocation.getRegisterA());
-      allocation.setRegister(new VariableRef("i#0"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("i#1"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("i#2"), RegisterAllocation.getRegisterX());
-      */
-
-      // Optimal Registers for flipper-rex2.kc
-      /*
-      allocation.setRegister(new VariableRef("plot::i#0"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("plot::i#1"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("plot::i#2"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("plot::i#3"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("plot::i#4"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("plot::x#0"), RegisterAllocation.getRegisterY());
-      allocation.setRegister(new VariableRef("plot::x#1"), RegisterAllocation.getRegisterY());
-      allocation.setRegister(new VariableRef("plot::x#2"), RegisterAllocation.getRegisterY());
-      allocation.setRegister(new VariableRef("plot::y#0"), new RegisterAllocation.RegisterZpByte(100));
-      allocation.setRegister(new VariableRef("plot::y#1"), new RegisterAllocation.RegisterZpByte(100));
-      allocation.setRegister(new VariableRef("plot::y#2"), new RegisterAllocation.RegisterZpByte(100));
-      allocation.setRegister(new VariableRef("plot::y#3"), new RegisterAllocation.RegisterZpByte(100));
-      allocation.setRegister(new VariableRef("plot::y#4"), new RegisterAllocation.RegisterZpByte(100));
-      allocation.setRegister(new VariableRef("plot::line#0"), new RegisterAllocation.RegisterZpPointerByte(101));
-      allocation.setRegister(new VariableRef("plot::line#1"), new RegisterAllocation.RegisterZpPointerByte(101));
-      allocation.setRegister(new VariableRef("plot::line#2"), new RegisterAllocation.RegisterZpPointerByte(101));
-      allocation.setRegister(new VariableRef("plot::line#3"), new RegisterAllocation.RegisterZpPointerByte(101));
-      allocation.setRegister(new VariableRef("plot::line#4"), new RegisterAllocation.RegisterZpPointerByte(101));
-      allocation.setRegister(new VariableRef("plot::$3"), RegisterAllocation.getRegisterA());
-      allocation.setRegister(new VariableRef("prepare::i#0"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("prepare::i#1"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("prepare::i#2"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("flip::srcIdx#0"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("flip::srcIdx#0"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("flip::srcIdx#1"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("flip::srcIdx#2"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("flip::srcIdx#3"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("flip::srcIdx#4"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("flip::dstIdx#0"), RegisterAllocation.getRegisterY());
-      allocation.setRegister(new VariableRef("flip::dstIdx#1"), RegisterAllocation.getRegisterY());
-      allocation.setRegister(new VariableRef("flip::dstIdx#2"), RegisterAllocation.getRegisterY());
-      allocation.setRegister(new VariableRef("flip::dstIdx#3"), RegisterAllocation.getRegisterY());
-      allocation.setRegister(new VariableRef("flip::dstIdx#4"), RegisterAllocation.getRegisterY());
-      allocation.setRegister(new VariableRef("flip::dstIdx#5"), RegisterAllocation.getRegisterY());
-      allocation.setRegister(new VariableRef("flip::c#0"), new RegisterAllocation.RegisterZpByte(103));
-      allocation.setRegister(new VariableRef("flip::c#1"), new RegisterAllocation.RegisterZpByte(103));
-      allocation.setRegister(new VariableRef("flip::c#2"), new RegisterAllocation.RegisterZpByte(103));
-      allocation.setRegister(new VariableRef("flip::r#0"), new RegisterAllocation.RegisterZpByte(104));
-      allocation.setRegister(new VariableRef("flip::r#1"), new RegisterAllocation.RegisterZpByte(104));
-      allocation.setRegister(new VariableRef("flip::r#2"), new RegisterAllocation.RegisterZpByte(104));
-      allocation.setRegister(new VariableRef("flip::r#3"), new RegisterAllocation.RegisterZpByte(104));
-      allocation.setRegister(new VariableRef("flip::r#4"), new RegisterAllocation.RegisterZpByte(104));
-      allocation.setRegister(new VariableRef("flip::i#0"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("flip::i#1"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("flip::i#2"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("flip::$0"), RegisterAllocation.getRegisterA());
-      allocation.setRegister(new VariableRef("flip::$8"), RegisterAllocation.getRegisterA());
-      allocation.setRegister(new VariableRef("flip::$4"), RegisterAllocation.getRegisterA());
-      allocation.setRegister(new VariableRef("main::$1"), RegisterAllocation.getRegisterA());
-      allocation.setRegister(new VariableRef("main::$3"), RegisterAllocation.getRegisterA());
-      allocation.setRegister(new VariableRef("main::c#0"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("main::c#1"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("main::c#2"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("main::c#3"), RegisterAllocation.getRegisterX());
-      allocation.setRegister(new VariableRef("main::c#4"), RegisterAllocation.getRegisterX());
-      */
-
-
-   }
-
-   int currentZp = 2;
-   private void performAllocation(Scope scope, RegisterAllocation allocation) {
-      for (Symbol symbol : scope.getAllSymbols()) {
-         if (symbol instanceof Scope) {
-            performAllocation((Scope) symbol, allocation);
-         } else if (symbol instanceof VariableIntermediate || symbol instanceof VariableVersion) {
-            Variable var = (Variable) symbol;
-            if (symbol.getType().equals(SymbolTypeBasic.BYTE)) {
-               allocation.setRegister(var.getRef(), new RegisterAllocation.RegisterZpByte(currentZp++));
-            } else if (symbol.getType().equals(SymbolTypeBasic.WORD)) {
-               allocation.setRegister(var.getRef(), new RegisterAllocation.RegisterZpWord(currentZp));
-               currentZp = currentZp + 2;
-            } else if (symbol.getType().equals(SymbolTypeBasic.BOOLEAN)) {
-               allocation.setRegister(var.getRef(), new RegisterAllocation.RegisterZpBool(currentZp++));
-            } else if (symbol.getType().equals(SymbolTypeBasic.VOID)) {
-               // No need to setRegister register for VOID value
-            } else if (symbol.getType() instanceof SymbolTypePointer) {
-               allocation.setRegister(var.getRef(), new RegisterAllocation.RegisterZpPointerByte(currentZp));
-               currentZp = currentZp + 2;
-            } else {
-               throw new RuntimeException("Unhandled variable type " + symbol);
-            }
-         }
-      }
-   }
-
-}
--- a/src/main/java/dk/camelot64/kickc/passes/Pass4RegistersFinalize.java
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass4RegistersFinalize.java
@ -29,14 +29,14 @@ public class Pass4RegistersFinalize extends Pass2Base {
   private void reallocateZp(LiveRangeEquivalenceClassSet liveRangeEquivalenceClassSet) {
      for (LiveRangeEquivalenceClass equivalenceClass : liveRangeEquivalenceClassSet.getEquivalenceClasses()) {
         RegisterAllocation.Register register = equivalenceClass.getRegister();
-         if(register.isZp()) {
-            String before = register.toString();
+         if(register==null || register.isZp()) {
+            String before = register==null?null:register.toString();
            VariableRef variable = equivalenceClass.getVariables().get(0);
            Variable symbol = getProgram().getScope().getVariable(variable);
            register = allocateNewRegisterZp(symbol.getType());
            equivalenceClass.setRegister(register);
-            if(!before.equals(register.toString())) {
-               getLog().append("Re-allocated ZP register from " + before + " to " + register.toString());
+            if(before==null || !before.equals(register.toString())) {
+               getLog().append("Allocated " + (before==null?"":("(was "+before+") ")) + equivalenceClass.toString());
            }
         }
      }
--- a/src/main/java/dk/camelot64/kickc/passes/Pass4ZeroPageAllocation.java
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass4ZeroPageAllocation.java
@ -25,14 +25,6 @@ public class Pass4ZeroPageAllocation extends Pass2Base {
         getLog().append(liveRangeEquivalenceClass.toString());
      }

-      // Coalesce over copy assignments
-      //EquivalenceClassCopyCoalescer equivalenceClassCopyCoalescer = new EquivalenceClassCopyCoalescer(liveRangeEquivalenceClassSet);
-      //equivalenceClassCopyCoalescer.visitGraph(getGraph());
-      //getLog().append("Copy Coalesced equivalence classes");
-      //for (LiveRangeEquivalenceClass liveRangeEquivalenceClass : liveRangeEquivalenceClassSet.getEquivalenceClasses()) {
-      //   getLog().append(liveRangeEquivalenceClass.toString());
-      //}
-
      // Add all other variables one by one to an available equivalence class - or create a new one
      EquivalenceClassAdder equivalenceClassAdder = new EquivalenceClassAdder(liveRangeEquivalenceClassSet);
      equivalenceClassAdder.visitGraph(getGraph());
@ -42,14 +34,13 @@ public class Pass4ZeroPageAllocation extends Pass2Base {
      }

      // Allocate zeropage registers to equivalence classes
-      RegisterAllocation allocation = new RegisterAllocation();
-      for (LiveRangeEquivalenceClass liveRangeEquivalenceClass : liveRangeEquivalenceClassSet.getEquivalenceClasses()) {
-         List<VariableRef> variables = liveRangeEquivalenceClass.getVariables();
-         Variable firstVar = getProgram().getScope().getVariable(variables.get(0));
-         RegisterAllocation.Register zpRegister = allocateNewRegisterZp(firstVar.getType());
-         liveRangeEquivalenceClass.setRegister(zpRegister);
-         getLog().append("Allocated " + zpRegister + " to " + liveRangeEquivalenceClass);
-      }
+   //   for (LiveRangeEquivalenceClass liveRangeEquivalenceClass : liveRangeEquivalenceClassSet.getEquivalenceClasses()) {
+   //      List<VariableRef> variables = liveRangeEquivalenceClass.getVariables();
+   //      Variable firstVar = getProgram().getScope().getVariable(variables.get(0));
+   //      RegisterAllocation.Register zpRegister = allocateNewRegisterZp(firstVar.getType());
+   //      liveRangeEquivalenceClass.setRegister(zpRegister);
+   //      getLog().append("Allocated " + zpRegister + " to " + liveRangeEquivalenceClass);
+   //   }
      getProgram().setLiveRangeEquivalenceClassSet(liveRangeEquivalenceClassSet);
   }

@ -69,8 +60,6 @@ public class Pass4ZeroPageAllocation extends Pass2Base {
         if (assignment.getlValue() instanceof VariableRef) {
            VariableRef lValVar = (VariableRef) assignment.getlValue();
            List<VariableRef> preferences = new ArrayList<>();
-            //addPreference(preferences, assignment.getrValue1());
-            //addPreference(preferences, assignment.getrValue2());
            addToEquivalenceClassSet(lValVar, preferences);
         }
         return null;
@ -106,48 +95,6 @@ public class Pass4ZeroPageAllocation extends Pass2Base {
         }
      }

-      private void addPreference(List<VariableRef> preferences, RValue rValue) {
-         if (rValue instanceof VariableRef) {
-            preferences.add((VariableRef) rValue);
-         }
-      }
-
-   }
-
-   /**
-    * Coalesce equivalence classes when they do not overlap based on all copy assignments to variables.
-    */
-   private class EquivalenceClassCopyCoalescer extends ControlFlowGraphBaseVisitor<Void> {
-
-      private LiveRangeEquivalenceClassSet liveRangeEquivalenceClassSet;
-
-      EquivalenceClassCopyCoalescer(LiveRangeEquivalenceClassSet liveRangeEquivalenceClassSet) {
-         this.liveRangeEquivalenceClassSet = liveRangeEquivalenceClassSet;
-      }
-
-      @Override
-      public Void visitAssignment(StatementAssignment assignment) {
-         if (assignment.getlValue() instanceof VariableRef) {
-            LiveRangeEquivalenceClass lValEquivalenceClass =
-                  liveRangeEquivalenceClassSet.getEquivalenceClass((VariableRef) assignment.getlValue());
-            if (lValEquivalenceClass != null && assignment.getOperator() == null && assignment.getrValue1() == null && assignment.getrValue2() instanceof VariableRef) {
-               // Found copy assignment to a variable in an equivalence class - attempt to coalesce
-               VariableRef assignVar = (VariableRef) assignment.getrValue2();
-               LiveRangeEquivalenceClass assignVarEquivalenceClass = liveRangeEquivalenceClassSet.getOrCreateEquivalenceClass(assignVar);
-               if (lValEquivalenceClass.equals(assignVarEquivalenceClass)) {
-                  getLog().append("Coalesced (already) " + assignment + " in " + lValEquivalenceClass);
-               } else if (!lValEquivalenceClass.getLiveRange().overlaps(assignVarEquivalenceClass.getLiveRange())) {
-                  lValEquivalenceClass.addAll(assignVarEquivalenceClass);
-                  liveRangeEquivalenceClassSet.remove(assignVarEquivalenceClass);
-                  getLog().append("Coalesced " + assignment + " into " + lValEquivalenceClass);
-               } else {
-                  getLog().append("Not coalescing " + assignment);
-               }
-            }
-         }
-         return null;
-      }
-
   }

   /**
--- a/src/main/java/dk/camelot64/kickc/test/TestCompilationOutput.java
+++ b/src/main/java/dk/camelot64/kickc/test/TestCompilationOutput.java
@ -24,6 +24,10 @@ public class TestCompilationOutput extends TestCase {
      helper = new ReferenceHelper("dk/camelot64/kickc/test/ref/");
   }

+   public void testInMemArray() throws IOException, URISyntaxException {
+      compileAndCompare("inmemarray");
+   }
+
   public void testVoronoi() throws IOException, URISyntaxException {
      compileAndCompare("voronoi");
   }
--- a/src/main/java/dk/camelot64/kickc/test/inmemarray.kc
+++ b/src/main/java/dk/camelot64/kickc/test/inmemarray.kc
@ -0,0 +1,15 @@
+
+byte* SCREEN = $0400;
+byte[] TXT = { 3, 1, 13, 5, 12, 15, 20, 32};
+
+main();
+
+void main() {
+   byte j = 0;
+   for(byte i : 0..100) {
+      SCREEN[i] = TXT[j];
+      if(++j==8) {
+         j = 0;
+      }
+   }
+}
--- a/src/main/java/dk/camelot64/kickc/test/ref/bresenham.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/bresenham.log
@ -391,6 +391,83 @@ CONTROL FLOW GRAPH WITH ASSIGNMENT CALL & RETURN
  to:@2
@end: scope:[]  from @2

+INITIAL SSA SYMBOL TABLE
+(byte~) $0
+(byte~) $1
+(boolean~) $10
+(byte~) $11
+(byte*~) $12
+(byte~) $13
+(byte~) $14
+(boolean~) $15
+(byte~) $2
+(byte~) $3
+(byte*~) $4
+(byte*~) $5
+(byte~) $6
+(byte*~) $7
+(byte~) $8
+(boolean~) $9
+(label) @1
+(label) @2
+(label) @3
+(label) @begin
+(label) @end
+(byte[1000]) SCREEN
+(byte[1000]) SCREEN#0
+(byte) STAR
+(byte) STAR#0
+(byte) STAR#1
+(byte) STAR#2
+(byte) STAR#3
+(byte*) cursor
+(byte*) cursor#0
+(byte*) cursor#1
+(byte*) cursor#2
+(byte*) cursor#3
+(byte*) cursor#4
+(byte*) cursor#5
+(byte) e
+(byte) e#0
+(byte) e#1
+(byte) e#2
+(byte) e#3
+(byte) e#4
+(byte) e#5
+(byte) x
+(byte) x#0
+(byte) x#1
+(byte) x#2
+(byte) x#3
+(byte) x#4
+(byte) x0
+(byte) x0#0
+(byte) x1
+(byte) x1#0
+(byte) x1#1
+(byte) x1#2
+(byte) x1#3
+(byte) xd
+(byte) xd#0
+(byte) xd#1
+(byte) xd#2
+(byte) xd#3
+(byte) y
+(byte) y#0
+(byte) y#1
+(byte) y#2
+(byte) y#3
+(byte) y#4
+(byte) y0
+(byte) y0#0
+(byte) y1
+(byte) y1#0
+(byte) yd
+(byte) yd#0
+(byte) yd#1
+(byte) yd#2
+(byte) yd#3
+
 Constant (byte) STAR#0 (byte) 81
 Constant (byte[1000]) SCREEN#0 (word) 1024
 Constant (byte) x0#0 (byte) 0
@ -948,6 +1025,38 @@ Multiple usages for variable. Not optimizing sub-constant (byte) y#2
 Multiple usages for variable. Not optimizing sub-constant (byte*) cursor#1
 Multiple usages for variable. Not optimizing sub-constant (byte) y#2
 Multiple usages for variable. Not optimizing sub-constant (byte*) cursor#1
+FINAL SYMBOL TABLE
+(label) @1
+(label) @2
+(label) @3
+(label) @begin
+(label) @end
+(byte[1000]) SCREEN
+(byte) STAR
+(byte*) cursor
+(byte*) cursor#1
+(byte*) cursor#2
+(byte*) cursor#3
+(byte*) cursor#5
+(byte) e
+(byte) e#1
+(byte) e#2
+(byte) e#3
+(byte) e#5
+(byte) x
+(byte) x#1
+(byte) x#2
+(byte) x0
+(byte) x1
+(byte) xd
+(byte) y
+(byte) y#1
+(byte) y#2
+(byte) y#4
+(byte) y0
+(byte) y1
+(byte) yd
+
 Block Sequence Planned @begin @1 @3 @2 @end 
 Added new block during phi lifting @5(between @2 and @1)
 Added new block during phi lifting @6(between @1 and @2)
@ -1146,10 +1255,10 @@ Complete equivalence classes
 [ x#2 x#1 ]
 [ e#3 e#5 e#1 e#2 ]
 [ y#2 y#4 y#1 ]
-Allocated zp ptr byte:2 to zp ptr byte:2 [ cursor#3 cursor#5 cursor#1 cursor#2 ]
-Allocated zp byte:4 to zp byte:4 [ x#2 x#1 ]
-Allocated zp byte:5 to zp byte:5 [ e#3 e#5 e#1 e#2 ]
-Allocated zp byte:6 to zp byte:6 [ y#2 y#4 y#1 ]
+Allocated zp ptr byte:2 [ cursor#3 cursor#5 cursor#1 cursor#2 ]
+Allocated zp byte:4 [ x#2 x#1 ]
+Allocated zp byte:5 [ e#3 e#5 e#1 e#2 ]
+Allocated zp byte:6 [ y#2 y#4 y#1 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
@ -1263,7 +1372,7 @@ REGISTER UPLIFT SCOPES
 Uplift Scope [] 55: zp byte:5 [ e#3 e#5 e#1 e#2 ] 46.75: zp ptr byte:2 [ cursor#3 cursor#5 cursor#1 cursor#2 ] 29.33: zp byte:6 [ y#2 y#4 y#1 ] 14.67: zp byte:4 [ x#2 x#1 ] 

 Uplifting [] best 1210 combination reg byte x [ e#3 e#5 e#1 e#2 ] zp ptr byte:2 [ cursor#3 cursor#5 cursor#1 cursor#2 ] zp byte:6 [ y#2 y#4 y#1 ] zp byte:4 [ x#2 x#1 ] 
-Re-allocated ZP register from zp byte:6 to zp byte:5
+Allocated (was zp byte:6) zp byte:5 [ y#2 y#4 y#1 ]
 Removing instruction jmp b1
 Removing instruction jmp b3
 Removing instruction jmp b2
--- a/src/main/java/dk/camelot64/kickc/test/ref/fibmem.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/fibmem.log
@ -197,6 +197,28 @@ main::@return: scope:[main]  from main::@1
  to:@return
@end: scope:[]  from @2

+INITIAL SSA SYMBOL TABLE
+(label) @2
+(label) @begin
+(label) @end
+(byte[15]) fibs
+(byte[15]) fibs#0
+(byte[15]) fibs#1
+(byte[15]) fibs#2
+(void()) main()
+(byte~) main::$0
+(byte~) main::$1
+(byte~) main::$2
+(byte~) main::$3
+(byte~) main::$4
+(boolean~) main::$5
+(label) main::@1
+(label) main::@return
+(byte) main::i
+(byte) main::i#0
+(byte) main::i#1
+(byte) main::i#2
+
 Culled Empty Block (label) @2
 Succesful SSA optimization Pass2CullEmptyBlocks
 CONTROL FLOW GRAPH
@ -428,6 +450,20 @@ main::@return: scope:[main]  from main::@1
 Multiple usages for variable. Not optimizing sub-constant (byte) main::i#2
 Multiple usages for variable. Not optimizing sub-constant (byte) main::i#2
 Multiple usages for variable. Not optimizing sub-constant (byte) main::i#2
+FINAL SYMBOL TABLE
+(label) @begin
+(label) @end
+(byte[15]) fibs
+(void()) main()
+(byte~) main::$1
+(byte~) main::$3
+(byte~) main::$4
+(label) main::@1
+(label) main::@return
+(byte) main::i
+(byte) main::i#1
+(byte) main::i#2
+
 Block Sequence Planned @begin @end main main::@1 main::@return 
 Added new block during phi lifting main::@3(between main::@1 and main::@1)
 Block Sequence Planned @begin @end main main::@1 main::@return main::@3 
@ -554,10 +590,10 @@ Complete equivalence classes
 [ main::$1 ]
 [ main::$3 ]
 [ main::$4 ]
-Allocated zp byte:2 to zp byte:2 [ main::i#2 main::i#1 ]
-Allocated zp byte:3 to zp byte:3 [ main::$1 ]
-Allocated zp byte:4 to zp byte:4 [ main::$3 ]
-Allocated zp byte:5 to zp byte:5 [ main::$4 ]
+Allocated zp byte:2 [ main::i#2 main::i#1 ]
+Allocated zp byte:3 [ main::$1 ]
+Allocated zp byte:4 [ main::$3 ]
+Allocated zp byte:5 [ main::$4 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
--- a/src/main/java/dk/camelot64/kickc/test/ref/flipper-rex2.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/flipper-rex2.log
@ -1033,6 +1033,183 @@ plot::@return: scope:[plot]  from plot::@3
  to:@return
@end: scope:[]  from @5

+INITIAL SSA SYMBOL TABLE
+(label) @5
+(label) @begin
+(label) @end
+(byte*) RASTER
+(byte*) RASTER#0
+(byte*) RASTER#1
+(byte*) RASTER#10
+(byte*) RASTER#2
+(byte*) RASTER#3
+(byte*) RASTER#4
+(byte*) RASTER#5
+(byte*) RASTER#6
+(byte*) RASTER#7
+(byte*) RASTER#8
+(byte*) RASTER#9
+(byte[1000]) SCREEN
+(byte[1000]) SCREEN#0
+(byte[1000]) SCREEN#1
+(byte[1000]) SCREEN#10
+(byte[1000]) SCREEN#11
+(byte[1000]) SCREEN#2
+(byte[1000]) SCREEN#3
+(byte[1000]) SCREEN#4
+(byte[1000]) SCREEN#5
+(byte[1000]) SCREEN#6
+(byte[1000]) SCREEN#7
+(byte[1000]) SCREEN#8
+(byte[1000]) SCREEN#9
+(byte[256]) buffer1
+(byte[256]) buffer1#0
+(byte[256]) buffer1#1
+(byte[256]) buffer1#10
+(byte[256]) buffer1#11
+(byte[256]) buffer1#12
+(byte[256]) buffer1#13
+(byte[256]) buffer1#14
+(byte[256]) buffer1#15
+(byte[256]) buffer1#16
+(byte[256]) buffer1#17
+(byte[256]) buffer1#18
+(byte[256]) buffer1#19
+(byte[256]) buffer1#2
+(byte[256]) buffer1#20
+(byte[256]) buffer1#21
+(byte[256]) buffer1#22
+(byte[256]) buffer1#3
+(byte[256]) buffer1#4
+(byte[256]) buffer1#5
+(byte[256]) buffer1#6
+(byte[256]) buffer1#7
+(byte[256]) buffer1#8
+(byte[256]) buffer1#9
+(byte[256]) buffer2
+(byte[256]) buffer2#0
+(byte[256]) buffer2#1
+(byte[256]) buffer2#10
+(byte[256]) buffer2#11
+(byte[256]) buffer2#12
+(byte[256]) buffer2#13
+(byte[256]) buffer2#14
+(byte[256]) buffer2#15
+(byte[256]) buffer2#16
+(byte[256]) buffer2#2
+(byte[256]) buffer2#3
+(byte[256]) buffer2#4
+(byte[256]) buffer2#5
+(byte[256]) buffer2#6
+(byte[256]) buffer2#7
+(byte[256]) buffer2#8
+(byte[256]) buffer2#9
+(void()) flip()
+(byte~) flip::$0
+(byte~) flip::$1
+(boolean~) flip::$2
+(boolean~) flip::$3
+(byte~) flip::$4
+(boolean~) flip::$5
+(label) flip::@1
+(label) flip::@2
+(label) flip::@3
+(label) flip::@4
+(label) flip::@5
+(label) flip::@return
+(byte) flip::c
+(byte) flip::c#0
+(byte) flip::c#1
+(byte) flip::c#2
+(byte) flip::dstIdx
+(byte) flip::dstIdx#0
+(byte) flip::dstIdx#1
+(byte) flip::dstIdx#2
+(byte) flip::dstIdx#3
+(byte) flip::dstIdx#4
+(byte) flip::dstIdx#5
+(byte) flip::i
+(byte) flip::i#0
+(byte) flip::i#1
+(byte) flip::i#2
+(byte) flip::r
+(byte) flip::r#0
+(byte) flip::r#1
+(byte) flip::r#2
+(byte) flip::r#3
+(byte) flip::r#4
+(byte) flip::srcIdx
+(byte) flip::srcIdx#0
+(byte) flip::srcIdx#1
+(byte) flip::srcIdx#2
+(byte) flip::srcIdx#3
+(byte) flip::srcIdx#4
+(void()) main()
+(byte~) main::$1
+(boolean~) main::$2
+(byte~) main::$3
+(boolean~) main::$4
+(boolean~) main::$5
+(label) main::@1
+(label) main::@10
+(label) main::@11
+(label) main::@2
+(label) main::@3
+(label) main::@4
+(label) main::@6
+(label) main::@7
+(label) main::@9
+(label) main::@return
+(byte) main::c
+(byte) main::c#0
+(byte) main::c#1
+(byte) main::c#2
+(byte) main::c#3
+(byte) main::c#4
+(byte) main::c#5
+(void()) plot()
+(byte~) plot::$0
+(byte*~) plot::$1
+(byte*~) plot::$2
+(byte~) plot::$3
+(boolean~) plot::$4
+(byte*~) plot::$5
+(boolean~) plot::$6
+(label) plot::@1
+(label) plot::@2
+(label) plot::@3
+(label) plot::@return
+(byte) plot::i
+(byte) plot::i#0
+(byte) plot::i#1
+(byte) plot::i#2
+(byte) plot::i#3
+(byte) plot::i#4
+(byte*) plot::line
+(byte*) plot::line#0
+(byte*) plot::line#1
+(byte*) plot::line#2
+(byte*) plot::line#3
+(byte*) plot::line#4
+(byte) plot::x
+(byte) plot::x#0
+(byte) plot::x#1
+(byte) plot::x#2
+(byte) plot::y
+(byte) plot::y#0
+(byte) plot::y#1
+(byte) plot::y#2
+(byte) plot::y#3
+(byte) plot::y#4
+(void()) prepare()
+(boolean~) prepare::$0
+(label) prepare::@1
+(label) prepare::@return
+(byte) prepare::i
+(byte) prepare::i#0
+(byte) prepare::i#1
+(byte) prepare::i#2
+
 Culled Empty Block (label) @5
 Succesful SSA optimization Pass2CullEmptyBlocks
 CONTROL FLOW GRAPH
@ -3491,6 +3668,78 @@ Multiple usages for variable. Not optimizing sub-constant (byte) flip::srcIdx#2
 Multiple usages for variable. Not optimizing sub-constant (byte) flip::i#2
 Multiple usages for variable. Not optimizing sub-constant (byte) flip::i#2
 Multiple usages for variable. Not optimizing sub-constant (byte) plot::i#2
+FINAL SYMBOL TABLE
+(label) @begin
+(label) @end
+(byte*) RASTER
+(byte[1000]) SCREEN
+(byte[256]) buffer1
+(byte[256]) buffer2
+(void()) flip()
+(byte~) flip::$0
+(byte~) flip::$4
+(label) flip::@1
+(label) flip::@2
+(label) flip::@3
+(label) flip::@4
+(label) flip::@return
+(byte) flip::c
+(byte) flip::c#1
+(byte) flip::c#2
+(byte) flip::dstIdx
+(byte) flip::dstIdx#1
+(byte) flip::dstIdx#2
+(byte) flip::dstIdx#3
+(byte) flip::dstIdx#5
+(byte) flip::i
+(byte) flip::i#1
+(byte) flip::i#2
+(byte) flip::r
+(byte) flip::r#1
+(byte) flip::r#2
+(byte) flip::srcIdx
+(byte) flip::srcIdx#1
+(byte) flip::srcIdx#2
+(byte) flip::srcIdx#3
+(void()) main()
+(byte~) main::$1
+(byte~) main::$3
+(label) main::@10
+(label) main::@11
+(label) main::@3
+(label) main::@4
+(label) main::@6
+(label) main::@7
+(label) main::@return
+(byte) main::c
+(byte) main::c#1
+(byte) main::c#2
+(void()) plot()
+(byte~) plot::$3
+(label) plot::@1
+(label) plot::@2
+(label) plot::@3
+(label) plot::@return
+(byte) plot::i
+(byte) plot::i#1
+(byte) plot::i#2
+(byte) plot::i#3
+(byte*) plot::line
+(byte*) plot::line#1
+(byte*) plot::line#2
+(byte) plot::x
+(byte) plot::x#1
+(byte) plot::x#2
+(byte) plot::y
+(byte) plot::y#1
+(byte) plot::y#2
+(void()) prepare()
+(label) prepare::@1
+(label) prepare::@return
+(byte) prepare::i
+(byte) prepare::i#1
+(byte) prepare::i#2
+
 Block Sequence Planned @begin @end main main::@3 main::@4 main::@6 main::@7 main::@10 main::@11 main::@return plot plot::@1 plot::@2 plot::@3 plot::@return flip flip::@1 flip::@2 flip::@4 flip::@3 flip::@return prepare prepare::@1 prepare::@return 
 Added new block during phi lifting main::@12(between main::@6 and main::@3)
 Added new block during phi lifting plot::@5(between plot::@3 and plot::@1)
@ -4091,22 +4340,22 @@ Complete equivalence classes
 [ plot::$3 ]
 [ flip::$0 ]
 [ flip::$4 ]
-Allocated zp byte:2 to zp byte:2 [ main::c#2 main::c#1 ]
-Allocated zp ptr byte:3 to zp ptr byte:3 [ plot::line#2 plot::line#1 ]
-Allocated zp byte:5 to zp byte:5 [ plot::y#2 plot::y#1 ]
-Allocated zp byte:6 to zp byte:6 [ plot::i#2 plot::i#3 plot::i#1 ]
-Allocated zp byte:7 to zp byte:7 [ plot::x#2 plot::x#1 ]
-Allocated zp byte:8 to zp byte:8 [ flip::r#2 flip::r#1 ]
-Allocated zp byte:9 to zp byte:9 [ flip::srcIdx#2 flip::srcIdx#3 flip::srcIdx#1 ]
-Allocated zp byte:10 to zp byte:10 [ flip::dstIdx#3 flip::dstIdx#5 flip::dstIdx#2 flip::dstIdx#1 ]
-Allocated zp byte:11 to zp byte:11 [ flip::c#2 flip::c#1 ]
-Allocated zp byte:12 to zp byte:12 [ flip::i#2 flip::i#1 ]
-Allocated zp byte:13 to zp byte:13 [ prepare::i#2 prepare::i#1 ]
-Allocated zp byte:14 to zp byte:14 [ main::$1 ]
-Allocated zp byte:15 to zp byte:15 [ main::$3 ]
-Allocated zp byte:16 to zp byte:16 [ plot::$3 ]
-Allocated zp byte:17 to zp byte:17 [ flip::$0 ]
-Allocated zp byte:18 to zp byte:18 [ flip::$4 ]
+Allocated zp byte:2 [ main::c#2 main::c#1 ]
+Allocated zp ptr byte:3 [ plot::line#2 plot::line#1 ]
+Allocated zp byte:5 [ plot::y#2 plot::y#1 ]
+Allocated zp byte:6 [ plot::i#2 plot::i#3 plot::i#1 ]
+Allocated zp byte:7 [ plot::x#2 plot::x#1 ]
+Allocated zp byte:8 [ flip::r#2 flip::r#1 ]
+Allocated zp byte:9 [ flip::srcIdx#2 flip::srcIdx#3 flip::srcIdx#1 ]
+Allocated zp byte:10 [ flip::dstIdx#3 flip::dstIdx#5 flip::dstIdx#2 flip::dstIdx#1 ]
+Allocated zp byte:11 [ flip::c#2 flip::c#1 ]
+Allocated zp byte:12 [ flip::i#2 flip::i#1 ]
+Allocated zp byte:13 [ prepare::i#2 prepare::i#1 ]
+Allocated zp byte:14 [ main::$1 ]
+Allocated zp byte:15 [ main::$3 ]
+Allocated zp byte:16 [ plot::$3 ]
+Allocated zp byte:17 [ flip::$0 ]
+Allocated zp byte:18 [ flip::$4 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
@ -4431,9 +4680,9 @@ Uplifting [main] best 125624 combination reg byte a [ main::$1 ] reg byte a [ ma
 Uplifting [prepare] best 125524 combination reg byte x [ prepare::i#2 prepare::i#1 ] 
 Uplifting [] best 125524 combination 
 Coalescing zero page register [ zp byte:5 [ plot::y#2 plot::y#1 ] ] with [ zp byte:8 [ flip::r#2 flip::r#1 ] ]
-Re-allocated ZP register from zp ptr byte:3 to zp ptr byte:2
-Re-allocated ZP register from zp byte:5 to zp byte:4
-Re-allocated ZP register from zp byte:11 to zp byte:5
+Allocated (was zp ptr byte:3) zp ptr byte:2 [ plot::line#2 plot::line#1 ]
+Allocated (was zp byte:5) zp byte:4 [ plot::y#2 plot::y#1 flip::r#2 flip::r#1 ]
+Allocated (was zp byte:11) zp byte:5 [ flip::c#2 flip::c#1 ]
 Removing instruction jmp bend
 Removing instruction jmp b3
 Removing instruction jmp b4
--- a/src/main/java/dk/camelot64/kickc/test/ref/forclassicmin.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/forclassicmin.log
@ -162,6 +162,25 @@ main::@return: scope:[main]  from main::@1
  to:@end
@end: scope:[]  from @2

+INITIAL SSA SYMBOL TABLE
+(label) @1
+(label) @2
+(label) @begin
+(label) @end
+(byte*) SCREEN
+(byte*) SCREEN#0
+(byte*) SCREEN#1
+(byte*) SCREEN#2
+(byte*) SCREEN#3
+(void()) main()
+(boolean~) main::$0
+(label) main::@1
+(label) main::@return
+(byte) main::i
+(byte) main::i#0
+(byte) main::i#1
+(byte) main::i#2
+
 Culled Empty Block (label) @2
 Succesful SSA optimization Pass2CullEmptyBlocks
 CONTROL FLOW GRAPH
@ -330,6 +349,18 @@ main::@return: scope:[main]  from main::@1

 Multiple usages for variable. Not optimizing sub-constant (byte) main::i#2
 Multiple usages for variable. Not optimizing sub-constant (byte) main::i#2
+FINAL SYMBOL TABLE
+(label) @1
+(label) @begin
+(label) @end
+(byte*) SCREEN
+(void()) main()
+(label) main::@1
+(label) main::@return
+(byte) main::i
+(byte) main::i#1
+(byte) main::i#2
+
 Block Sequence Planned @begin @1 @end main main::@1 main::@return 
 Added new block during phi lifting main::@3(between main::@1 and main::@1)
 Block Sequence Planned @begin @1 @end main main::@1 main::@return main::@3 
@ -437,7 +468,7 @@ Initial phi equivalence classes
 [ main::i#2 main::i#1 ]
 Complete equivalence classes
 [ main::i#2 main::i#1 ]
-Allocated zp byte:2 to zp byte:2 [ main::i#2 main::i#1 ]
+Allocated zp byte:2 [ main::i#2 main::i#1 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
--- a/src/main/java/dk/camelot64/kickc/test/ref/forrangemin.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/forrangemin.log
@ -241,6 +241,39 @@ main::@return: scope:[main]  from main::@2
  to:@end
@end: scope:[]  from @2

+INITIAL SSA SYMBOL TABLE
+(label) @1
+(label) @2
+(label) @begin
+(label) @end
+(byte*) SCREEN1
+(byte*) SCREEN1#0
+(byte*) SCREEN1#1
+(byte*) SCREEN1#2
+(byte*) SCREEN1#3
+(byte*) SCREEN2
+(byte*) SCREEN2#0
+(byte*) SCREEN2#1
+(byte*) SCREEN2#2
+(byte*) SCREEN2#3
+(byte*) SCREEN2#4
+(byte*) SCREEN2#5
+(void()) main()
+(boolean~) main::$0
+(boolean~) main::$1
+(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::j
+(byte) main::j#0
+(byte) main::j#1
+(byte) main::j#2
+
 Culled Empty Block (label) @2
 Succesful SSA optimization Pass2CullEmptyBlocks
 CONTROL FLOW GRAPH
@ -557,6 +590,23 @@ main::@return: scope:[main]  from main::@2

 Multiple usages for variable. Not optimizing sub-constant (byte) main::i#2
 Multiple usages for variable. Not optimizing sub-constant (byte) main::j#2
+FINAL SYMBOL TABLE
+(label) @1
+(label) @begin
+(label) @end
+(byte*) SCREEN1
+(byte*) SCREEN2
+(void()) main()
+(label) main::@1
+(label) main::@2
+(label) main::@return
+(byte) main::i
+(byte) main::i#1
+(byte) main::i#2
+(byte) main::j
+(byte) main::j#1
+(byte) main::j#2
+
 Block Sequence Planned @begin @1 @end main main::@1 main::@2 main::@return 
 Added new block during phi lifting main::@5(between main::@1 and main::@1)
 Added new block during phi lifting main::@6(between main::@2 and main::@2)
@ -703,8 +753,8 @@ Initial phi equivalence classes
 Complete equivalence classes
 [ main::i#2 main::i#1 ]
 [ main::j#2 main::j#1 ]
-Allocated zp byte:2 to zp byte:2 [ main::i#2 main::i#1 ]
-Allocated zp byte:3 to zp byte:3 [ main::j#2 main::j#1 ]
+Allocated zp byte:2 [ main::i#2 main::i#1 ]
+Allocated zp byte:3 [ main::j#2 main::j#1 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
--- a/src/main/java/dk/camelot64/kickc/test/ref/ifmin.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/ifmin.log
@ -203,6 +203,31 @@ main::@return: scope:[main]  from main::@2
  to:@return
@end: scope:[]  from @2

+INITIAL SSA SYMBOL TABLE
+(label) @2
+(label) @begin
+(label) @end
+(byte*) SCREEN
+(byte*) SCREEN#0
+(byte*) SCREEN#1
+(byte*) SCREEN#2
+(byte*) SCREEN#3
+(byte*) SCREEN#4
+(void()) main()
+(boolean~) main::$0
+(boolean~) main::$1
+(boolean~) main::$2
+(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
+
 Culled Empty Block (label) @2
 Succesful SSA optimization Pass2CullEmptyBlocks
 CONTROL FLOW GRAPH
@ -441,6 +466,19 @@ main::@return: scope:[main]  from main::@2
  to:@return
@end: scope:[]  from @begin

+FINAL SYMBOL TABLE
+(label) @begin
+(label) @end
+(byte*) SCREEN
+(void()) main()
+(label) main::@1
+(label) main::@2
+(label) main::@3
+(label) main::@return
+(byte) main::i
+(byte) main::i#1
+(byte) main::i#2
+
 Block Sequence Planned @begin @end main main::@1 main::@3 main::@2 main::@return 
 Added new block during phi lifting main::@5(between main::@2 and main::@1)
 Block Sequence Planned @begin @end main main::@1 main::@3 main::@2 main::@return main::@5 
@ -558,7 +596,7 @@ Initial phi equivalence classes
 [ main::i#2 main::i#1 ]
 Complete equivalence classes
 [ main::i#2 main::i#1 ]
-Allocated zp byte:2 to zp byte:2 [ main::i#2 main::i#1 ]
+Allocated zp byte:2 [ main::i#2 main::i#1 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
--- a/src/main/java/dk/camelot64/kickc/test/ref/loopmin.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/loopmin.log
@ -156,6 +156,29 @@ CONTROL FLOW GRAPH WITH ASSIGNMENT CALL & RETURN
  to:@2
@end: scope:[]  from @2

+INITIAL SSA SYMBOL TABLE
+(boolean~) $0
+(boolean~) $1
+(byte~) $2
+(boolean~) $3
+(label) @1
+(label) @2
+(label) @3
+(label) @begin
+(label) @end
+(byte) i
+(byte) i#0
+(byte) i#1
+(byte) i#2
+(byte) i#3
+(byte) i#4
+(byte) s
+(byte) s#0
+(byte) s#1
+(byte) s#2
+(byte) s#3
+(byte) s#4
+
 Constant (byte) i#0 (byte) 10
 Constant (byte) s#0 (byte) 0
 Succesful SSA optimization Pass2ConstantPropagation
@ -278,6 +301,20 @@ CONTROL FLOW GRAPH
  to:@2
@end: scope:[]  from @2

+FINAL SYMBOL TABLE
+(label) @1
+(label) @2
+(label) @3
+(label) @begin
+(label) @end
+(byte) i
+(byte) i#1
+(byte) i#2
+(byte) s
+(byte) s#1
+(byte) s#2
+(byte) s#4
+
 Block Sequence Planned @begin @1 @3 @2 @end 
 Added new block during phi lifting @5(between @2 and @1)
 Added new block during phi lifting @6(between @1 and @2)
@ -403,8 +440,8 @@ Initial phi equivalence classes
 Complete equivalence classes
 [ i#2 i#1 ]
 [ s#2 s#4 s#1 ]
-Allocated zp byte:2 to zp byte:2 [ i#2 i#1 ]
-Allocated zp byte:3 to zp byte:3 [ s#2 s#4 s#1 ]
+Allocated zp byte:2 [ i#2 i#1 ]
+Allocated zp byte:3 [ s#2 s#4 s#1 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
--- a/src/main/java/dk/camelot64/kickc/test/ref/loopnest.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/loopnest.log
@ -258,6 +258,36 @@ nest::@return: scope:[nest]  from nest::@1
  to:@return
@end: scope:[]  from @3

+INITIAL SSA SYMBOL TABLE
+(label) @3
+(label) @begin
+(label) @end
+(byte*) SCREEN
+(byte*) SCREEN#0
+(byte*) SCREEN#1
+(byte*) SCREEN#2
+(byte*) SCREEN#3
+(byte*) SCREEN#4
+(byte*) SCREEN#5
+(void()) main()
+(boolean~) main::$1
+(label) main::@1
+(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
+(void()) nest()
+(boolean~) nest::$0
+(label) nest::@1
+(label) nest::@return
+(byte) nest::j
+(byte) nest::j#0
+(byte) nest::j#1
+(byte) nest::j#2
+
 Culled Empty Block (label) @3
 Succesful SSA optimization Pass2CullEmptyBlocks
 CONTROL FLOW GRAPH
@ -554,6 +584,24 @@ nest::@return: scope:[nest]  from nest::@1
  to:@return
@end: scope:[]  from @begin

+FINAL SYMBOL TABLE
+(label) @begin
+(label) @end
+(byte*) SCREEN
+(void()) main()
+(label) main::@1
+(label) main::@3
+(label) main::@return
+(byte) main::i
+(byte) main::i#1
+(byte) main::i#2
+(void()) nest()
+(label) nest::@1
+(label) nest::@return
+(byte) nest::j
+(byte) nest::j#1
+(byte) nest::j#2
+
 Block Sequence Planned @begin @end main main::@1 main::@3 main::@return nest nest::@1 nest::@return 
 Added new block during phi lifting main::@4(between main::@3 and main::@1)
 Added new block during phi lifting nest::@3(between nest::@1 and nest::@1)
@ -733,8 +781,8 @@ Initial phi equivalence classes
 Complete equivalence classes
 [ main::i#2 main::i#1 ]
 [ nest::j#2 nest::j#1 ]
-Allocated zp byte:2 to zp byte:2 [ main::i#2 main::i#1 ]
-Allocated zp byte:3 to zp byte:3 [ nest::j#2 nest::j#1 ]
+Allocated zp byte:2 [ main::i#2 main::i#1 ]
+Allocated zp byte:3 [ nest::j#2 nest::j#1 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
--- a/src/main/java/dk/camelot64/kickc/test/ref/loopnest2.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/loopnest2.log
@ -559,6 +559,84 @@ nest2::@return: scope:[nest2]  from nest2::@3
  to:@return
@end: scope:[]  from @4

+INITIAL SSA SYMBOL TABLE
+(label) @4
+(label) @begin
+(label) @end
+(byte*) SCREEN
+(byte*) SCREEN#0
+(byte*) SCREEN#1
+(byte*) SCREEN#10
+(byte*) SCREEN#11
+(byte*) SCREEN#12
+(byte*) SCREEN#13
+(byte*) SCREEN#14
+(byte*) SCREEN#2
+(byte*) SCREEN#3
+(byte*) SCREEN#4
+(byte*) SCREEN#5
+(byte*) SCREEN#6
+(byte*) SCREEN#7
+(byte*) SCREEN#8
+(byte*) SCREEN#9
+(void()) main()
+(boolean~) main::$1
+(boolean~) main::$2
+(label) main::@1
+(label) main::@2
+(label) main::@3
+(label) main::@5
+(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::i#5
+(byte) main::j
+(byte) main::j#0
+(byte) main::j#1
+(byte) main::j#2
+(byte) main::j#3
+(void()) nest1()
+(boolean~) nest1::$1
+(boolean~) nest1::$2
+(label) nest1::@1
+(label) nest1::@2
+(label) nest1::@3
+(label) nest1::@5
+(label) nest1::@return
+(byte) nest1::i
+(byte) nest1::i#0
+(byte) nest1::i#1
+(byte) nest1::i#2
+(byte) nest1::i#3
+(byte) nest1::i#4
+(byte) nest1::i#5
+(byte) nest1::j
+(byte) nest1::j#0
+(byte) nest1::j#1
+(byte) nest1::j#2
+(byte) nest1::j#3
+(void()) nest2()
+(boolean~) nest2::$0
+(boolean~) nest2::$1
+(label) nest2::@1
+(label) nest2::@2
+(label) nest2::@3
+(label) nest2::@return
+(byte) nest2::i
+(byte) nest2::i#0
+(byte) nest2::i#1
+(byte) nest2::i#2
+(byte) nest2::i#3
+(byte) nest2::i#4
+(byte) nest2::j
+(byte) nest2::j#0
+(byte) nest2::j#1
+(byte) nest2::j#2
+
 Culled Empty Block (label) @4
 Succesful SSA optimization Pass2CullEmptyBlocks
 CONTROL FLOW GRAPH
@ -1446,6 +1524,46 @@ nest2::@return: scope:[nest2]  from nest2::@3
  to:@return
@end: scope:[]  from @begin

+FINAL SYMBOL TABLE
+(label) @begin
+(label) @end
+(byte*) SCREEN
+(void()) main()
+(label) main::@1
+(label) main::@2
+(label) main::@3
+(label) main::@5
+(label) main::@return
+(byte) main::i
+(byte) main::i#1
+(byte) main::i#2
+(byte) main::j
+(byte) main::j#1
+(byte) main::j#2
+(void()) nest1()
+(label) nest1::@1
+(label) nest1::@2
+(label) nest1::@3
+(label) nest1::@5
+(label) nest1::@return
+(byte) nest1::i
+(byte) nest1::i#1
+(byte) nest1::i#2
+(byte) nest1::j
+(byte) nest1::j#1
+(byte) nest1::j#2
+(void()) nest2()
+(label) nest2::@1
+(label) nest2::@2
+(label) nest2::@3
+(label) nest2::@return
+(byte) nest2::i
+(byte) nest2::i#1
+(byte) nest2::i#2
+(byte) nest2::j
+(byte) nest2::j#1
+(byte) nest2::j#2
+
 Block Sequence Planned @begin @end main main::@1 main::@2 main::@5 main::@3 main::@return nest1 nest1::@1 nest1::@2 nest1::@5 nest1::@3 nest1::@return nest2 nest2::@1 nest2::@2 nest2::@3 nest2::@return 
 Added new block during phi lifting main::@6(between main::@3 and main::@1)
 Added new block during phi lifting main::@7(between main::@5 and main::@2)
@ -1922,12 +2040,12 @@ Complete equivalence classes
 [ nest1::j#2 nest1::j#1 ]
 [ nest2::i#2 nest2::i#1 ]
 [ nest2::j#2 nest2::j#1 ]
-Allocated zp byte:2 to zp byte:2 [ main::i#2 main::i#1 ]
-Allocated zp byte:3 to zp byte:3 [ main::j#2 main::j#1 ]
-Allocated zp byte:4 to zp byte:4 [ nest1::i#2 nest1::i#1 ]
-Allocated zp byte:5 to zp byte:5 [ nest1::j#2 nest1::j#1 ]
-Allocated zp byte:6 to zp byte:6 [ nest2::i#2 nest2::i#1 ]
-Allocated zp byte:7 to zp byte:7 [ nest2::j#2 nest2::j#1 ]
+Allocated zp byte:2 [ main::i#2 main::i#1 ]
+Allocated zp byte:3 [ main::j#2 main::j#1 ]
+Allocated zp byte:4 [ nest1::i#2 nest1::i#1 ]
+Allocated zp byte:5 [ nest1::j#2 nest1::j#1 ]
+Allocated zp byte:6 [ nest2::i#2 nest2::i#1 ]
+Allocated zp byte:7 [ nest2::j#2 nest2::j#1 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
--- a/src/main/java/dk/camelot64/kickc/test/ref/loopsplit.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/loopsplit.log
@ -248,6 +248,35 @@ main::@return: scope:[main]  from main::@1
  to:@return
@end: scope:[]  from @2

+INITIAL SSA SYMBOL TABLE
+(label) @2
+(label) @begin
+(label) @end
+(void()) main()
+(boolean~) main::$0
+(boolean~) main::$1
+(boolean~) main::$2
+(label) main::@1
+(label) main::@2
+(label) main::@4
+(label) main::@8
+(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::i#5
+(byte) main::s
+(byte) main::s#0
+(byte) main::s#1
+(byte) main::s#2
+(byte) main::s#3
+(byte) main::s#4
+(byte) main::s#5
+(byte) main::s#6
+
 Culled Empty Block (label) @2
 Succesful SSA optimization Pass2CullEmptyBlocks
 CONTROL FLOW GRAPH
@ -421,6 +450,23 @@ main::@return: scope:[main]  from main::@1
  to:@return
@end: scope:[]  from @begin

+FINAL SYMBOL TABLE
+(label) @begin
+(label) @end
+(void()) main()
+(label) main::@1
+(label) main::@2
+(label) main::@4
+(label) main::@8
+(label) main::@return
+(byte) main::i
+(byte) main::i#1
+(byte) main::i#2
+(byte) main::s
+(byte) main::s#1
+(byte) main::s#2
+(byte) main::s#3
+
 Block Sequence Planned @begin @end main main::@1 main::@return main::@2 main::@8 main::@4 
 Block Sequence Planned @begin @end main main::@1 main::@return main::@2 main::@8 main::@4 
 CONTROL FLOW GRAPH - PHI LIFTED
@ -568,8 +614,8 @@ Initial phi equivalence classes
 Complete equivalence classes
 [ main::i#2 main::i#1 ]
 [ main::s#3 main::s#1 main::s#2 ]
-Allocated zp byte:2 to zp byte:2 [ main::i#2 main::i#1 ]
-Allocated zp byte:3 to zp byte:3 [ main::s#3 main::s#1 main::s#2 ]
+Allocated zp byte:2 [ main::i#2 main::i#1 ]
+Allocated zp byte:3 [ main::s#3 main::s#1 main::s#2 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
--- a/src/main/java/dk/camelot64/kickc/test/ref/minus.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/minus.log
@ -116,6 +116,22 @@ CONTROL FLOW GRAPH WITH ASSIGNMENT CALL & RETURN
  to:@end
@end: scope:[]  from @1

+INITIAL SSA SYMBOL TABLE
+(byte~) $0
+(byte~) $1
+(byte~) $2
+(boolean~) $3
+(label) @1
+(label) @begin
+(label) @end
+(byte) i
+(byte) i#0
+(byte) i#1
+(byte) i#2
+(byte[16]) p
+(byte[16]) p#0
+(byte[16]) p#1
+
 Constant (byte[16]) p#0 (word) 4352
 Constant (byte) i#0 (byte) 5
 Succesful SSA optimization Pass2ConstantPropagation
@ -223,6 +239,16 @@ Multiple usages for variable. Not optimizing sub-constant (byte) i#2
 Multiple usages for variable. Not optimizing sub-constant (byte) i#2
 Multiple usages for variable. Not optimizing sub-constant (byte) i#2
 Multiple usages for variable. Not optimizing sub-constant (byte) i#2
+FINAL SYMBOL TABLE
+(byte~) $1
+(label) @1
+(label) @begin
+(label) @end
+(byte) i
+(byte) i#1
+(byte) i#2
+(byte[16]) p
+
 Block Sequence Planned @begin @1 @end 
 Added new block during phi lifting @3(between @1 and @1)
 Block Sequence Planned @begin @1 @end @3 
@ -306,8 +332,8 @@ Added variable $1 to zero page equivalence class [ $1 ]
 Complete equivalence classes
 [ i#2 i#1 ]
 [ $1 ]
-Allocated zp byte:2 to zp byte:2 [ i#2 i#1 ]
-Allocated zp byte:3 to zp byte:3 [ $1 ]
+Allocated zp byte:2 [ i#2 i#1 ]
+Allocated zp byte:3 [ $1 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
--- a/src/main/java/dk/camelot64/kickc/test/ref/modglobal.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/modglobal.log
@ -312,6 +312,63 @@ inccnt::@return: scope:[inccnt]  from inccnt
  to:@return
@end: scope:[]  from @3

+INITIAL SSA SYMBOL TABLE
+(label) @3
+(label) @begin
+(label) @end
+(byte[256]) SCREEN
+(byte[256]) SCREEN#0
+(byte[256]) SCREEN#1
+(byte[256]) SCREEN#2
+(byte[256]) SCREEN#3
+(byte) cnt
+(byte) cnt#0
+(byte) cnt#1
+(byte) cnt#10
+(byte) cnt#11
+(byte) cnt#12
+(byte) cnt#13
+(byte) cnt#14
+(byte) cnt#2
+(byte) cnt#3
+(byte) cnt#4
+(byte) cnt#5
+(byte) cnt#6
+(byte) cnt#7
+(byte) cnt#8
+(byte) cnt#9
+(byte) cnt2
+(byte) cnt2#0
+(byte) cnt2#1
+(byte) cnt2#10
+(byte) cnt2#11
+(byte) cnt2#12
+(byte) cnt2#13
+(byte) cnt2#2
+(byte) cnt2#3
+(byte) cnt2#4
+(byte) cnt2#5
+(byte) cnt2#6
+(byte) cnt2#7
+(byte) cnt2#8
+(byte) cnt2#9
+(byte()) inccnt()
+(label) inccnt::@return
+(byte) inccnt::return
+(byte) inccnt::return#0
+(byte) inccnt::return#1
+(byte) inccnt::return#2
+(byte) inccnt::return#3
+(byte) inccnt::return#4
+(byte) inccnt::return#5
+(byte) inccnt::return#6
+(void()) main()
+(byte~) main::$0
+(byte~) main::$1
+(label) main::@1
+(label) main::@2
+(label) main::@return
+
 Constant (byte) cnt#0 (byte) 0
 Constant (byte) cnt2#0 (byte) 0
 Constant (byte[256]) SCREEN#0 (word) 1024
@ -539,6 +596,28 @@ Not aliassing across scopes: inccnt::return#0 cnt#1
 Not aliassing across scopes: main::$0 inccnt::return#0
 Not aliassing across scopes: main::$1 inccnt::return#0
 Not aliassing across scopes: inccnt::return#0 cnt#1
+FINAL SYMBOL TABLE
+(label) @begin
+(label) @end
+(byte[256]) SCREEN
+(byte) cnt
+(byte) cnt#1
+(byte) cnt#12
+(byte) cnt#3
+(byte) cnt2
+(byte) cnt2#1
+(byte) cnt2#11
+(byte()) inccnt()
+(label) inccnt::@return
+(byte) inccnt::return
+(byte) inccnt::return#0
+(void()) main()
+(byte~) main::$0
+(byte~) main::$1
+(label) main::@1
+(label) main::@2
+(label) main::@return
+
 Block Sequence Planned @begin @end main main::@1 main::@2 main::@return inccnt inccnt::@return 
 Block Sequence Planned @begin @end main main::@1 main::@2 main::@return inccnt inccnt::@return 
 CONTROL FLOW GRAPH - PHI LIFTED
@ -711,12 +790,12 @@ Complete equivalence classes
 [ main::$1 ]
 [ cnt#1 ]
 [ inccnt::return#0 ]
-Allocated zp byte:2 to zp byte:2 [ cnt#12 cnt#3 ]
-Allocated zp byte:3 to zp byte:3 [ cnt2#11 cnt2#1 ]
-Allocated zp byte:4 to zp byte:4 [ main::$0 ]
-Allocated zp byte:5 to zp byte:5 [ main::$1 ]
-Allocated zp byte:6 to zp byte:6 [ cnt#1 ]
-Allocated zp byte:7 to zp byte:7 [ inccnt::return#0 ]
+Allocated zp byte:2 [ cnt#12 cnt#3 ]
+Allocated zp byte:3 [ cnt2#11 cnt2#1 ]
+Allocated zp byte:4 [ main::$0 ]
+Allocated zp byte:5 [ main::$1 ]
+Allocated zp byte:6 [ cnt#1 ]
+Allocated zp byte:7 [ inccnt::return#0 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
--- a/src/main/java/dk/camelot64/kickc/test/ref/modglobalmin.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/modglobalmin.log
@ -241,6 +241,39 @@ inccnt::@return: scope:[inccnt]  from inccnt
  to:@return
@end: scope:[]  from @3

+INITIAL SSA SYMBOL TABLE
+(label) @3
+(label) @begin
+(label) @end
+(byte[256]) SCREEN
+(byte[256]) SCREEN#0
+(byte[256]) SCREEN#1
+(byte[256]) SCREEN#2
+(byte[256]) SCREEN#3
+(byte) cnt
+(byte) cnt#0
+(byte) cnt#1
+(byte) cnt#10
+(byte) cnt#11
+(byte) cnt#12
+(byte) cnt#13
+(byte) cnt#14
+(byte) cnt#15
+(byte) cnt#2
+(byte) cnt#3
+(byte) cnt#4
+(byte) cnt#5
+(byte) cnt#6
+(byte) cnt#7
+(byte) cnt#8
+(byte) cnt#9
+(void()) inccnt()
+(label) inccnt::@return
+(void()) main()
+(label) main::@1
+(label) main::@2
+(label) main::@return
+
 Constant (byte) cnt#0 (byte) 0
 Constant (byte[256]) SCREEN#0 (word) 1024
 Succesful SSA optimization Pass2ConstantPropagation
@ -418,6 +451,22 @@ inccnt::@return: scope:[inccnt]  from inccnt
  to:@return
@end: scope:[]  from @begin

+FINAL SYMBOL TABLE
+(label) @begin
+(label) @end
+(byte[256]) SCREEN
+(byte) cnt
+(byte) cnt#1
+(byte) cnt#10
+(byte) cnt#13
+(byte) cnt#3
+(void()) inccnt()
+(label) inccnt::@return
+(void()) main()
+(label) main::@1
+(label) main::@2
+(label) main::@return
+
 Block Sequence Planned @begin @end main main::@1 main::@2 main::@return inccnt inccnt::@return 
 Block Sequence Planned @begin @end main main::@1 main::@2 main::@return inccnt inccnt::@return 
 CONTROL FLOW GRAPH - PHI LIFTED
@ -554,9 +603,9 @@ Complete equivalence classes
 [ cnt#13 cnt#3 ]
 [ cnt#1 ]
 [ cnt#10 ]
-Allocated zp byte:2 to zp byte:2 [ cnt#13 cnt#3 ]
-Allocated zp byte:3 to zp byte:3 [ cnt#1 ]
-Allocated zp byte:4 to zp byte:4 [ cnt#10 ]
+Allocated zp byte:2 [ cnt#13 cnt#3 ]
+Allocated zp byte:3 [ cnt#1 ]
+Allocated zp byte:4 [ cnt#10 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
--- a/src/main/java/dk/camelot64/kickc/test/ref/ptrtest.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/ptrtest.log
@ -773,6 +773,89 @@ rvaluevar::@return: scope:[rvaluevar]  from rvaluevar::@1
  to:@return
@end: scope:[]  from @6

+INITIAL SSA SYMBOL TABLE
+(label) @6
+(label) @begin
+(label) @end
+(void()) lvalue()
+(boolean~) lvalue::$0
+(label) lvalue::@1
+(label) lvalue::@2
+(label) lvalue::@return
+(byte[1024]) lvalue::SCREEN
+(byte[1024]) lvalue::SCREEN#0
+(byte[1024]) lvalue::SCREEN#1
+(byte[1024]) lvalue::SCREEN#2
+(byte) lvalue::i
+(byte) lvalue::i#0
+(byte) lvalue::i#1
+(byte) lvalue::i#2
+(byte) lvalue::i#3
+(void()) lvaluevar()
+(boolean~) lvaluevar::$0
+(label) lvaluevar::@1
+(label) lvaluevar::@2
+(label) lvaluevar::@return
+(byte) lvaluevar::b
+(byte) lvaluevar::b#0
+(byte) lvaluevar::b#1
+(byte) lvaluevar::b#2
+(byte) lvaluevar::i
+(byte) lvaluevar::i#0
+(byte) lvaluevar::i#1
+(byte) lvaluevar::i#2
+(byte) lvaluevar::i#3
+(byte*) lvaluevar::screen
+(byte*) lvaluevar::screen#0
+(byte*) lvaluevar::screen#1
+(byte*) lvaluevar::screen#2
+(byte*) lvaluevar::screen#3
+(void()) main()
+(label) main::@1
+(label) main::@2
+(label) main::@3
+(label) main::@4
+(label) main::@return
+(void()) rvalue()
+(byte~) rvalue::$0
+(byte~) rvalue::$1
+(boolean~) rvalue::$2
+(byte~) rvalue::$3
+(label) rvalue::@1
+(label) rvalue::@2
+(label) rvalue::@return
+(byte[1024]) rvalue::SCREEN
+(byte[1024]) rvalue::SCREEN#0
+(byte[1024]) rvalue::SCREEN#1
+(byte[1024]) rvalue::SCREEN#2
+(byte) rvalue::b
+(byte) rvalue::b#0
+(byte) rvalue::b#1
+(byte) rvalue::b#2
+(byte) rvalue::i
+(byte) rvalue::i#0
+(byte) rvalue::i#1
+(byte) rvalue::i#2
+(byte) rvalue::i#3
+(void()) rvaluevar()
+(boolean~) rvaluevar::$0
+(byte~) rvaluevar::$1
+(label) rvaluevar::@1
+(label) rvaluevar::@2
+(label) rvaluevar::@return
+(byte) rvaluevar::b
+(byte) rvaluevar::b#0
+(byte) rvaluevar::i
+(byte) rvaluevar::i#0
+(byte) rvaluevar::i#1
+(byte) rvaluevar::i#2
+(byte) rvaluevar::i#3
+(byte*) rvaluevar::screen
+(byte*) rvaluevar::screen#0
+(byte*) rvaluevar::screen#1
+(byte*) rvaluevar::screen#2
+(byte*) rvaluevar::screen#3
+
 Culled Empty Block (label) @6
 Culled Empty Block (label) main::@4
 Succesful SSA optimization Pass2CullEmptyBlocks
@ -1471,6 +1554,58 @@ rvaluevar::@return: scope:[rvaluevar]  from rvaluevar::@1

 Multiple usages for variable. Not optimizing sub-constant (byte) rvalue::i#2
 Multiple usages for variable. Not optimizing sub-constant (byte) rvalue::i#2
+FINAL SYMBOL TABLE
+(label) @begin
+(label) @end
+(void()) lvalue()
+(label) lvalue::@1
+(label) lvalue::@2
+(label) lvalue::@return
+(byte[1024]) lvalue::SCREEN
+(byte) lvalue::i
+(byte) lvalue::i#1
+(byte) lvalue::i#2
+(void()) lvaluevar()
+(label) lvaluevar::@1
+(label) lvaluevar::@2
+(label) lvaluevar::@return
+(byte) lvaluevar::b
+(byte) lvaluevar::i
+(byte) lvaluevar::i#1
+(byte) lvaluevar::i#2
+(byte*) lvaluevar::screen
+(byte*) lvaluevar::screen#1
+(byte*) lvaluevar::screen#2
+(void()) main()
+(label) main::@1
+(label) main::@2
+(label) main::@3
+(label) main::@return
+(void()) rvalue()
+(label) rvalue::@1
+(label) rvalue::@2
+(label) rvalue::@return
+(byte[1024]) rvalue::SCREEN
+(byte) rvalue::b
+(byte) rvalue::b#0
+(byte) rvalue::b#1
+(byte) rvalue::b#2
+(byte) rvalue::i
+(byte) rvalue::i#1
+(byte) rvalue::i#2
+(void()) rvaluevar()
+(label) rvaluevar::@1
+(label) rvaluevar::@2
+(label) rvaluevar::@return
+(byte) rvaluevar::b
+(byte) rvaluevar::b#0
+(byte) rvaluevar::i
+(byte) rvaluevar::i#1
+(byte) rvaluevar::i#2
+(byte*) rvaluevar::screen
+(byte*) rvaluevar::screen#1
+(byte*) rvaluevar::screen#2
+
 Block Sequence Planned @begin @end main main::@1 main::@2 main::@3 main::@return lvaluevar lvaluevar::@1 lvaluevar::@return lvaluevar::@2 rvaluevar rvaluevar::@1 rvaluevar::@return rvaluevar::@2 rvalue rvalue::@1 rvalue::@return rvalue::@2 lvalue lvalue::@1 lvalue::@return lvalue::@2 
 Block Sequence Planned @begin @end main main::@1 main::@2 main::@3 main::@return lvaluevar lvaluevar::@1 lvaluevar::@return lvaluevar::@2 rvaluevar rvaluevar::@1 rvaluevar::@return rvaluevar::@2 rvalue rvalue::@1 rvalue::@return rvalue::@2 lvalue lvalue::@1 lvalue::@return lvalue::@2 
 CONTROL FLOW GRAPH - PHI LIFTED
@ -1867,16 +2002,16 @@ Complete equivalence classes
 [ rvalue::b#0 ]
 [ rvalue::b#1 ]
 [ rvalue::b#2 ]
-Allocated zp byte:2 to zp byte:2 [ lvaluevar::i#2 lvaluevar::i#1 ]
-Allocated zp ptr byte:3 to zp ptr byte:3 [ lvaluevar::screen#2 lvaluevar::screen#1 ]
-Allocated zp byte:5 to zp byte:5 [ rvaluevar::i#2 rvaluevar::i#1 ]
-Allocated zp ptr byte:6 to zp ptr byte:6 [ rvaluevar::screen#2 rvaluevar::screen#1 ]
-Allocated zp byte:8 to zp byte:8 [ rvalue::i#2 rvalue::i#1 ]
-Allocated zp byte:9 to zp byte:9 [ lvalue::i#2 lvalue::i#1 ]
-Allocated zp byte:10 to zp byte:10 [ rvaluevar::b#0 ]
-Allocated zp byte:11 to zp byte:11 [ rvalue::b#0 ]
-Allocated zp byte:12 to zp byte:12 [ rvalue::b#1 ]
-Allocated zp byte:13 to zp byte:13 [ rvalue::b#2 ]
+Allocated zp byte:2 [ lvaluevar::i#2 lvaluevar::i#1 ]
+Allocated zp ptr byte:3 [ lvaluevar::screen#2 lvaluevar::screen#1 ]
+Allocated zp byte:5 [ rvaluevar::i#2 rvaluevar::i#1 ]
+Allocated zp ptr byte:6 [ rvaluevar::screen#2 rvaluevar::screen#1 ]
+Allocated zp byte:8 [ rvalue::i#2 rvalue::i#1 ]
+Allocated zp byte:9 [ lvalue::i#2 lvalue::i#1 ]
+Allocated zp byte:10 [ rvaluevar::b#0 ]
+Allocated zp byte:11 [ rvalue::b#0 ]
+Allocated zp byte:12 [ rvalue::b#1 ]
+Allocated zp byte:13 [ rvalue::b#2 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
@ -2115,7 +2250,7 @@ Uplifting [lvalue] best 1575 combination reg byte x [ lvalue::i#2 lvalue::i#1 ]
 Uplifting [main] best 1575 combination 
 Uplifting [] best 1575 combination 
 Coalescing zero page register [ zp ptr byte:3 [ lvaluevar::screen#2 lvaluevar::screen#1 ] ] with [ zp ptr byte:6 [ rvaluevar::screen#2 rvaluevar::screen#1 ] ]
-Re-allocated ZP register from zp ptr byte:3 to zp ptr byte:2
+Allocated (was zp ptr byte:3) zp ptr byte:2 [ lvaluevar::screen#2 lvaluevar::screen#1 rvaluevar::screen#2 rvaluevar::screen#1 ]
 Removing instruction jmp bend
 Removing instruction jmp b1
 Removing instruction jmp b2
--- a/src/main/java/dk/camelot64/kickc/test/ref/ptrtestmin.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/ptrtestmin.log
@ -193,6 +193,28 @@ main::@return: scope:[main]  from main::@1
  to:@return
@end: scope:[]  from @2

+INITIAL SSA SYMBOL TABLE
+(label) @2
+(label) @begin
+(label) @end
+(void()) main()
+(boolean~) main::$0
+(byte~) main::$1
+(label) main::@1
+(label) main::@2
+(label) main::@return
+(byte[1024]) main::SCREEN
+(byte[1024]) main::SCREEN#0
+(byte[1024]) main::SCREEN#1
+(byte[1024]) main::SCREEN#2
+(byte) main::b
+(byte) main::b#0
+(byte) main::i
+(byte) main::i#0
+(byte) main::i#1
+(byte) main::i#2
+(byte) main::i#3
+
 Culled Empty Block (label) @2
 Succesful SSA optimization Pass2CullEmptyBlocks
 CONTROL FLOW GRAPH
@ -341,6 +363,20 @@ main::@return: scope:[main]  from main::@1

 Multiple usages for variable. Not optimizing sub-constant (byte) main::i#2
 Multiple usages for variable. Not optimizing sub-constant (byte) main::i#2
+FINAL SYMBOL TABLE
+(label) @begin
+(label) @end
+(void()) main()
+(label) main::@1
+(label) main::@2
+(label) main::@return
+(byte[1024]) main::SCREEN
+(byte) main::b
+(byte) main::b#0
+(byte) main::i
+(byte) main::i#1
+(byte) main::i#2
+
 Block Sequence Planned @begin @end main main::@1 main::@return main::@2 
 Block Sequence Planned @begin @end main main::@1 main::@return main::@2 
 CONTROL FLOW GRAPH - PHI LIFTED
@ -448,8 +484,8 @@ Added variable main::b#0 to zero page equivalence class [ main::b#0 ]
 Complete equivalence classes
 [ main::i#2 main::i#1 ]
 [ main::b#0 ]
-Allocated zp byte:2 to zp byte:2 [ main::i#2 main::i#1 ]
-Allocated zp byte:3 to zp byte:3 [ main::b#0 ]
+Allocated zp byte:2 [ main::i#2 main::i#1 ]
+Allocated zp byte:3 [ main::b#0 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
--- a/src/main/java/dk/camelot64/kickc/test/ref/summin.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/summin.log
@ -228,6 +228,52 @@ sum::@return: scope:[sum]  from sum
  to:@return
@end: scope:[]  from @4

+INITIAL SSA SYMBOL TABLE
+(byte~) $0
+(byte~) $1
+(byte~) $2
+(byte~) $3
+(byte~) $4
+(label) @2
+(label) @3
+(label) @4
+(label) @begin
+(label) @end
+(byte) s1
+(byte) s1#0
+(byte) s1#1
+(byte) s1#2
+(byte) s2
+(byte) s2#0
+(byte) s2#1
+(byte) s3
+(byte) s3#0
+(byte) s4
+(byte) s4#0
+(byte()) sum((byte) sum::a , (byte) sum::b)
+(byte~) sum::$0
+(label) sum::@return
+(byte) sum::a
+(byte) sum::a#0
+(byte) sum::a#1
+(byte) sum::a#2
+(byte) sum::a#3
+(byte) sum::b
+(byte) sum::b#0
+(byte) sum::b#1
+(byte) sum::b#2
+(byte) sum::b#3
+(byte) sum::return
+(byte) sum::return#0
+(byte) sum::return#1
+(byte) sum::return#2
+(byte) sum::return#3
+(byte) sum::return#4
+(byte) sum::return#5
+(byte) sum::return#6
+(byte) sum::return#7
+(byte) sum::return#8
+
 Constant (byte) sum::a#0 (byte) 1
 Constant (byte) sum::b#0 (byte) 2
 Constant (byte) sum::a#1 (byte) 3
@ -317,6 +363,30 @@ sum::@return: scope:[sum]  from sum
 Not aliassing across scopes: s1#0 sum::return#0
 Not aliassing across scopes: s2#0 sum::return#0
 Not aliassing across scopes: s3#0 sum::return#0
+FINAL SYMBOL TABLE
+(byte~) $3
+(label) @2
+(label) @3
+(label) @4
+(label) @begin
+(label) @end
+(byte) s1
+(byte) s1#0
+(byte) s2
+(byte) s2#0
+(byte) s3
+(byte) s3#0
+(byte) s4
+(byte) s4#0
+(byte()) sum((byte) sum::a , (byte) sum::b)
+(label) sum::@return
+(byte) sum::a
+(byte) sum::a#3
+(byte) sum::b
+(byte) sum::b#3
+(byte) sum::return
+(byte) sum::return#0
+
 Block Sequence Planned @begin @2 @3 @4 @end sum sum::@return 
 Block Sequence Planned @begin @2 @3 @4 @end sum sum::@return 
 CONTROL FLOW GRAPH - PHI LIFTED
@ -488,14 +558,14 @@ Complete equivalence classes
 [ $3 ]
 [ s4#0 ]
 [ sum::return#0 ]
-Allocated zp byte:2 to zp byte:2 [ sum::a#3 ]
-Allocated zp byte:3 to zp byte:3 [ sum::b#3 ]
-Allocated zp byte:4 to zp byte:4 [ s1#0 ]
-Allocated zp byte:5 to zp byte:5 [ s2#0 ]
-Allocated zp byte:6 to zp byte:6 [ s3#0 ]
-Allocated zp byte:7 to zp byte:7 [ $3 ]
-Allocated zp byte:8 to zp byte:8 [ s4#0 ]
-Allocated zp byte:9 to zp byte:9 [ sum::return#0 ]
+Allocated zp byte:2 [ sum::a#3 ]
+Allocated zp byte:3 [ sum::b#3 ]
+Allocated zp byte:4 [ s1#0 ]
+Allocated zp byte:5 [ s2#0 ]
+Allocated zp byte:6 [ s3#0 ]
+Allocated zp byte:7 [ $3 ]
+Allocated zp byte:8 [ s4#0 ]
+Allocated zp byte:9 [ sum::return#0 ]
 INITIAL ASM
 //SEG0 @begin
 bbegin:
@ -590,8 +660,8 @@ Uplift Scope [sum] 2: zp byte:2 [ sum::a#3 ] 2: zp byte:3 [ sum::b#3 ] 1.6: zp b

 Uplifting [] best 107 combination reg byte a [ s4#0 ] reg byte a [ $3 ] zp byte:6 [ s3#0 ] reg byte x [ s2#0 ] zp byte:4 [ s1#0 ] 
 Uplifting [sum] best 79 combination reg byte y [ sum::a#3 ] reg byte a [ sum::b#3 ] reg byte a [ sum::return#0 ] 
-Re-allocated ZP register from zp byte:4 to zp byte:2
-Re-allocated ZP register from zp byte:6 to zp byte:3
+Allocated (was zp byte:4) zp byte:2 [ s1#0 ]
+Allocated (was zp byte:6) zp byte:3 [ s3#0 ]
 Removing instruction jmp b2
 Removing instruction jmp b3
 Removing instruction jmp b4
--- a/src/main/java/dk/camelot64/kickc/test/ref/useglobal.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/useglobal.log
@ -98,6 +98,16 @@ main::@return: scope:[main]  from main
  to:@return
@end: scope:[]  from @2

+INITIAL SSA SYMBOL TABLE
+(label) @2
+(label) @begin
+(label) @end
+(byte*) SCREEN
+(byte*) SCREEN#0
+(byte*) SCREEN#1
+(void()) main()
+(label) main::@return
+
 Culled Empty Block (label) @2
 Succesful SSA optimization Pass2CullEmptyBlocks
 CONTROL FLOW GRAPH
@ -143,6 +153,13 @@ main::@return: scope:[main]  from main
  to:@return
@end: scope:[]  from @begin

+FINAL SYMBOL TABLE
+(label) @begin
+(label) @end
+(byte*) SCREEN
+(void()) main()
+(label) main::@return
+
 Block Sequence Planned @begin @end main main::@return 
 Block Sequence Planned @begin @end main main::@return 
 CONTROL FLOW GRAPH - PHI LIFTED
--- a/src/main/java/dk/camelot64/kickc/test/ref/voronoi.asm
+++ b/src/main/java/dk/camelot64/kickc/test/ref/voronoi.asm
@ -123,7 +123,7 @@ render: {
    inc $5
    lda $5
    cmp #$28
-    bcc b2
+    bne b2
    lda $3
    clc
    adc #$28
@ -134,7 +134,7 @@ render: {
    inc $2
    lda $2
    cmp #$19
-    bcc b1
+    bne b1
    rts
 }
 findcol: {
--- a/src/main/java/dk/camelot64/kickc/test/ref/voronoi.cfg
+++ b/src/main/java/dk/camelot64/kickc/test/ref/voronoi.cfg
@ -114,12 +114,12 @@ render::@5: scope:[render]  from render::@2
  [56] (byte) render::col#0 ← (byte) findcol::return#0 [ render::x#2 render::y#2 render::colline#2 render::col#0 ]
  [57] *((byte*) render::colline#2 + (byte) render::x#2) ← (byte) render::col#0 [ render::x#2 render::y#2 render::colline#2 ]
  [58] (byte) render::x#1 ← ++ (byte) render::x#2 [ render::x#1 render::y#2 render::colline#2 ]
-  [59] if((byte) render::x#1<(byte) 40) goto render::@2 [ render::x#1 render::y#2 render::colline#2 ]
+  [59] if((byte) render::x#1!=(byte) 40) goto render::@2 [ render::x#1 render::y#2 render::colline#2 ]
  to:render::@3
 render::@3: scope:[render]  from render::@5
  [60] (byte*) render::colline#1 ← (byte*) render::colline#2 + (byte) 40 [ render::colline#1 render::y#2 ]
  [61] (byte) render::y#1 ← ++ (byte) render::y#2 [ render::y#1 render::colline#1 ]
-  [62] if((byte) render::y#1<(byte) 25) goto render::@1 [ render::y#1 render::colline#1 ]
+  [62] if((byte) render::y#1!=(byte) 25) goto render::@1 [ render::y#1 render::colline#1 ]
  to:render::@return
 render::@return: scope:[render]  from render::@3
  [63] return  [ ]
--- a/src/main/java/dk/camelot64/kickc/test/ref/voronoi.log
+++ b/src/main/java/dk/camelot64/kickc/test/ref/voronoi.log
--- a/src/main/java/dk/camelot64/kickc/test/voronoi.kc
+++ b/src/main/java/dk/camelot64/kickc/test/voronoi.kc
@ -63,30 +63,26 @@ void addpoint(byte x, byte y, byte c) {
 }

 void initscreen() {
-  byte* screen = SCREEN;
-  do {
+  for( byte* screen = SCREEN; screen<SCREEN+$03e8; ++screen) {
    *screen = FILL;
-  } while(++screen<SCREEN+$03e8)
+  }
 }

 void render() {
  byte* colline = COLORS;
-  byte y=0;
-  do {
-    byte x=0;
-    do {
+  for( byte y : 0.. 24) {
+    for( byte x : 0..39) {
      byte col = findcol(x, y);
      colline[x] = col;
-    } while(++x < 40)
+    }
    colline = colline+40;
-  } while(++y < 25)
+  }
 }

 byte findcol(byte x, byte y) {
  byte mindiff = 255;
  byte mincol = 0;
-  byte i=0;
-  do {
+  for( byte i=0; i<numpoints; ++i) {
     byte xp = XPOS[i];
     byte yp = YPOS[i];
     if(x==xp) {
@ -109,7 +105,7 @@ byte findcol(byte x, byte y) {
       mindiff=diff;
       mincol = COLS[i];
     }
-  } while(++i<numpoints)
+  }
  return mincol;
 }