Implemented variable register weight analysis.

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

@@ -141,7 +141,8 @@ public class Compiler {
       new Pass3ZeroPageAllocation(program, log).allocate();
 
       new Pass3VariableRegisterWeightAnalysis(program, log).findWeights();
-
+      log.append("\nVARIABLE REGISTER WEIGHTS");
+      log.append(program.getScope().getSymbolTableContents(Variable.class));
 
       new Pass3ZeroPageCoalesce(program, log).allocate();
       new Pass3RegistersFinalize(program, log).allocate();

src/main/java/dk/camelot64/kickc/icl/LiveRange.java

@@ -47,6 +47,15 @@ public class LiveRange {
       public int getLastStatementIdx() {
          return lastStatementIdx;
       }
+
+      /** Get the number of statements in the live interval.
+       *
+       * @return The number of statements in the live interval.
+       */
+      public int size() {
+         return lastStatementIdx-firstStatementIdx+1;
+      }
+
    }
 
    public LiveRange() {
@@ -71,6 +80,19 @@ public class LiveRange {
       return index;
    }
 
+   /** Get the number of statements in the live range.
+    *
+    * @return The number of statements in the live range.
+    */
+   public int size() {
+      int s = 0;
+      for (LiveInterval interval : intervals) {
+         s += interval.size();
+      }
+      return s;
+   }
+
+
    /**
     * Add an index to the live range
     * @param index The index to add

src/main/java/dk/camelot64/kickc/icl/NaturalLoopSet.java

@@ -96,4 +96,13 @@ public class NaturalLoopSet {
       this.loops.remove(loop);
    }
 
+   public int getMaxLoopDepth(LabelRef block) {
+      int maxDepth = 0;
+      for (NaturalLoop loop : getLoopsContainingBlock(block)) {
+         if(loop.getDepth()>maxDepth) {
+            maxDepth = loop.getDepth();
+         }
+      }
+      return maxDepth;
+   }
 }

src/main/java/dk/camelot64/kickc/icl/Procedure.java

@@ -71,11 +71,11 @@ public class Procedure extends Scope {
       return super.getFullName();
    }
 
-   public String getSymbolTableContents(ProgramScope scope) {
+   public String getSymbolTableContents(ProgramScope scope, Class symbolClass) {
       StringBuilder res = new StringBuilder();
       res.append(toString(scope));
       res.append("\n");
-      res.append(super.getSymbolTableContents(scope));
+      res.append(super.getSymbolTableContents(scope, symbolClass));
       return res.toString();
    }
 
@@ -85,7 +85,8 @@ public class Procedure extends Scope {
    }
 
    @Override
-   RegisterAllocation getAllocation() {
+   @JsonIgnore
+   public RegisterAllocation getAllocation() {
       if(getScope()!=null) {
          return getScope().getAllocation();
       } else {
@@ -93,6 +94,16 @@ public class Procedure extends Scope {
       }
    }
 
+   @Override
+   @JsonIgnore
+   public VariableRegisterWeights getVariableRegisterWeights() {
+      if(getScope()!=null) {
+         return getScope().getVariableRegisterWeights();
+      } else {
+         return null;
+      }
+   }
+
    @Override
    public String toString() {
       return toString(null);

src/main/java/dk/camelot64/kickc/icl/ProgramScope.java

@@ -10,10 +10,9 @@ import java.util.HashMap;
 public class ProgramScope extends Scope {
 
    private RegisterAllocation allocation;
-
    private LiveRangeVariables liveRangeVariables;
-
    private LiveRangeEquivalenceClassSet liveRangeEquivalenceClassSet;
+   private VariableRegisterWeights variableRegisterWeights;
 
    public ProgramScope() {
       super("", null);
@@ -42,13 +41,13 @@ public class ProgramScope extends Scope {
    public RegisterAllocation.Register getRegister(Variable variable) {
       RegisterAllocation.Register register = null;
       if (allocation != null) {
-         register = allocation.getRegister(variable);
+         register = allocation.getRegister(variable.getRef());
       }
       return register;
    }
 
    @Override
-   RegisterAllocation getAllocation() {
+   public RegisterAllocation getAllocation() {
       return allocation;
    }
 
@@ -94,13 +93,18 @@ public class ProgramScope extends Scope {
 
    @JsonIgnore
    public String getSymbolTableContents() {
-      return getSymbolTableContents(this);
+      return getSymbolTableContents(this, null);
+   }
+
+   @JsonIgnore
+   public String getSymbolTableContents(Class symbolClass) {
+      return getSymbolTableContents(this, symbolClass);
    }
 
    @Override
-   public String getSymbolTableContents(ProgramScope scope) {
+   public String getSymbolTableContents(ProgramScope scope, Class symbolClass) {
       StringBuilder out = new StringBuilder();
-      out.append(super.getSymbolTableContents(scope));
+      out.append(super.getSymbolTableContents(scope, symbolClass));
       if(liveRangeEquivalenceClassSet!=null) {
          out.append("\n");
          for (LiveRangeEquivalenceClass liveRangeEquivalenceClass : liveRangeEquivalenceClassSet.getEquivalenceClasses()) {
@@ -116,4 +120,11 @@ public class ProgramScope extends Scope {
       return "program";
    }
 
+   public void setVariableRegisterWeights(VariableRegisterWeights variableRegisterWeights) {
+      this.variableRegisterWeights = variableRegisterWeights;
+   }
+
+   public VariableRegisterWeights getVariableRegisterWeights() {
+      return variableRegisterWeights;
+   }
 }

src/main/java/dk/camelot64/kickc/icl/RegisterAllocation.java

@@ -19,10 +19,6 @@ public class RegisterAllocation {
     * @param variable The variable
     * @return The allocated register.
     */
-   public Register getRegister(Variable variable) {
-      return allocation.get(variable.getRef());
-   }
-
    public Register getRegister(VariableRef ref) {
       return allocation.get(ref);
    }

src/main/java/dk/camelot64/kickc/icl/Scope.java

@@ -205,29 +205,40 @@ public abstract class Scope implements Symbol {
          return (Procedure) getSymbol(ref);
    }
 
-   abstract RegisterAllocation getAllocation();
+   public abstract RegisterAllocation getAllocation();
+
+   public abstract VariableRegisterWeights getVariableRegisterWeights();
 
    @JsonIgnore
-   public String getSymbolTableContents(ProgramScope scope) {
+   public String getSymbolTableContents(ProgramScope scope, Class symbolClass) {
       StringBuilder res = new StringBuilder();
       Set<String> names = symbols.keySet();
       List<String> sortedNames = new ArrayList<>(names);
       Collections.sort(sortedNames);
       RegisterAllocation allocation = getAllocation();
+      VariableRegisterWeights registerWeights = getVariableRegisterWeights();
       for (String name : sortedNames) {
          Symbol symbol = symbols.get(name);
          if (symbol instanceof Scope) {
-            res.append(((Scope) symbol).getSymbolTableContents(scope));
+            res.append(((Scope) symbol).getSymbolTableContents(scope, symbolClass));
          } else {
-            res.append(symbol.toString(scope));
-         }
-         if (symbol instanceof Variable && allocation!=null) {
-            RegisterAllocation.Register register = allocation.getRegister((Variable) symbol);
-            if (register != null) {
-               res.append(" " + register);
+            if (symbolClass == null || symbolClass.isInstance(symbol)) {
+               res.append(symbol.toString(scope));
+               if (symbol instanceof Variable && allocation != null) {
+                  RegisterAllocation.Register register = allocation.getRegister(((Variable) symbol).getRef());
+                  if (register != null) {
+                     res.append(" " + register);
+                  }
+               }
+               if (symbol instanceof Variable && registerWeights != null) {
+                  Double weight = registerWeights.getWeight(((Variable) symbol).getRef());
+                  if (weight != null) {
+                     res.append(" " + weight);
+                  }
+               }
+               res.append("\n");
             }
          }
-         res.append("\n");
       }
       return res.toString();
    }

src/main/java/dk/camelot64/kickc/icl/VariableRegisterWeights.java

@@ -0,0 +1,36 @@
+package dk.camelot64.kickc.icl;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+/**
+ * The register weights for each variable.
+ * The register weight signifies how beneficial it would be for the variable to assigned to a register (instead of zero page).
+ */
+public class VariableRegisterWeights {
+
+   private Map<VariableRef, Double> registerWeights;
+
+   public VariableRegisterWeights() {
+      this.registerWeights = new LinkedHashMap<>();
+   }
+
+   /**
+    * Add to the weight of a variable
+    *
+    * @param variableRef The variable
+    * @param w           The amount to add to the weight
+    */
+   public void addWeight(VariableRef variableRef, double w) {
+      Double weight = this.registerWeights.get(variableRef);
+      if (weight == null) {
+         weight = 0.0;
+      }
+      weight = weight + w;
+      this.registerWeights.put(variableRef, weight);
+   }
+
+   public Double getWeight(VariableRef variable) {
+      return registerWeights.get(variable);
+   }
+}

src/main/java/dk/camelot64/kickc/passes/Pass3VariableRegisterWeightAnalysis.java

@@ -1,15 +1,13 @@
 package dk.camelot64.kickc.passes;
 
 import dk.camelot64.kickc.CompileLog;
-import dk.camelot64.kickc.icl.ControlFlowBlock;
-import dk.camelot64.kickc.icl.Program;
-import dk.camelot64.kickc.icl.Statement;
+import dk.camelot64.kickc.icl.*;
 
 /**
  * Finds register weights for all variables.
- *
+ * <p>
  * The register weight signifies how beneficial it would be for the variable to assigned to a register (instead of zero page).
- *
+ * <p>
  * Uses Loop Depth and Live Ranges plus the statements of the control flow graph.
  * <p>
  * Based on ComputeWeight from http://compilers.cs.ucla.edu/fernando/projects/soc/reports/short_tech.pdf
@@ -18,6 +16,9 @@ public class Pass3VariableRegisterWeightAnalysis {
 
    private Program program;
    private CompileLog log;
+   private NaturalLoopSet loopSet;
+   private VariableRegisterWeights variableRegisterWeights;
+   private LiveRangeVariables liveRangeVariables;
 
    public Pass3VariableRegisterWeightAnalysis(Program program, CompileLog log) {
       this.program = program;
@@ -32,20 +33,76 @@ public class Pass3VariableRegisterWeightAnalysis {
       return log;
    }
 
-   /** Find register weights for all variables    */
+   /**
+    * Find register weights for all variables
+    */
    public void findWeights() {
 
+      variableRegisterWeights = new VariableRegisterWeights();
+      loopSet = program.getGraph().getLoopSet();
+      liveRangeVariables = program.getScope().getLiveRangeVariables();
+
       for (ControlFlowBlock block : program.getGraph().getAllBlocks()) {
          for (Statement statement : block.getStatements()) {
-
-
-
-
+            if (statement instanceof StatementPhiBlock) {
+               for (StatementPhiBlock.PhiVariable phiVariable : ((StatementPhiBlock) statement).getPhiVariables()) {
+                  // Add weights for the definition of the phi variable
+                  VariableRef philVariable = phiVariable.getVariable();
+                  for (StatementPhiBlock.PhiRValue phiRValue : phiVariable.getValues()) {
+                     if (phiRValue.getrValue() instanceof VariableRef) {
+                        double w = addWeight(philVariable, phiRValue.getPredecessor());
+                        //log.append("Definition of " + philVariable + " w+:" + w + " - [" + statement.getIndex()+"]");
+                     }
+                  }
+                  // Add weights for each usage of a variable
+                  for (StatementPhiBlock.PhiRValue phiRValue : phiVariable.getValues()) {
+                     addUsageWeightRValue(phiRValue.getrValue(), statement, phiRValue.getPredecessor());
+                  }
+               }
+            } else if (statement instanceof StatementAssignment) {
+               // Add weights for the definition of the variable
+               LValue lValue = ((StatementAssignment) statement).getlValue();
+               if (lValue instanceof VariableRef) {
+                  double w = addWeight((VariableRef) lValue, block.getLabel());
+                  //log.append("Definition of " + lValue + " w+:" + w + " - [" + statement.getIndex()+"]");
+               }
+               // Also add weight to used pointers
+               if(lValue instanceof PointerDereferenceSimple) {
+                  addUsageWeightRValue(((PointerDereference) lValue).getPointer(), statement, block.getLabel());
+               } else if(lValue instanceof PointerDereferenceIndexed) {
+                  addUsageWeightRValue(((PointerDereference) lValue).getPointer(), statement, block.getLabel());
+                  addUsageWeightRValue(((PointerDereferenceIndexed) lValue).getIndex(), statement, block.getLabel());
+               }
+               // Add weights for each usage of variables
+               addUsageWeightRValue(((StatementAssignment) statement).getrValue1(), statement, block.getLabel());
+               addUsageWeightRValue(((StatementAssignment) statement).getrValue2(), statement, block.getLabel());
+            } else if (statement instanceof StatementConditionalJump) {
+               // Add weights for each usage of variables
+               addUsageWeightRValue(((StatementConditionalJump) statement).getrValue1(), statement, block.getLabel());
+               addUsageWeightRValue(((StatementConditionalJump) statement).getrValue2(), statement, block.getLabel());
+            }
          }
       }
 
+      program.getScope().setVariableRegisterWeights(variableRegisterWeights);
 
    }
 
+   private void addUsageWeightRValue(Value rValue, Statement statement, LabelRef block) {
+      if (rValue instanceof VariableRef) {
+         double w = addWeight((VariableRef) rValue, block);
+         //log.append("Usage of " + rValue + " w+:" + w + " - [" + statement.getIndex()+"]");
+      }
+   }
+
+   private double addWeight(VariableRef variable, LabelRef block) {
+      int depth = loopSet.getMaxLoopDepth(block);
+      double w = 1.0 + Math.pow(10.0, depth);
+      LiveRange liveRange = liveRangeVariables.getLiveRange(variable);
+      int s = liveRange.size();
+      variableRegisterWeights.addWeight(variable, w/s);
+      return w/s;
+   }
+
 
 }

src/main/java/dk/camelot64/kickc/test/ref/bresenham.log

@@ -1023,6 +1023,39 @@ 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 ]
+
+VARIABLE REGISTER WEIGHTS
+(byte[1000]) SCREEN
+(byte) STAR
+(byte*) cursor
+(byte*) cursor#1 8.25
+(byte*) cursor#2 11.0
+(byte*) cursor#3 11.0
+(byte*) cursor#5 16.5
+(byte) e
+(byte) e#1 11.0
+(byte) e#2 22.0
+(byte) e#3 5.5
+(byte) e#5 16.5
+(byte) x
+(byte) x#1 3.666666666666667
+(byte) x#2 11.0
+(byte) x0
+(byte) x1
+(byte) xd
+(byte) y
+(byte) y#1 7.333333333333333
+(byte) y#2 5.5
+(byte) y#4 16.5
+(byte) y0
+(byte) y1
+(byte) yd
+
+zp ptr byte:2 [ cursor#3 cursor#5 cursor#1 cursor#2 ]
+zp byte:4 [ x#2 x#1 ]
+zp byte:5 [ e#3 e#5 e#1 e#2 ]
+zp byte:6 [ y#2 y#4 y#1 ]
+
 Re-allocated ZP register from zp ptr byte:2 to zp ptr byte:2
 Re-allocated ZP register from zp byte:4 to zp byte:4
 Re-allocated ZP register from zp byte:5 to zp byte:5
@@ -1272,25 +1305,25 @@ FINAL SYMBOL TABLE
 (byte[1000]) SCREEN
 (byte) STAR
 (byte*) cursor
-(byte*) cursor#1 zp ptr byte:2
-(byte*) cursor#2 zp ptr byte:2
-(byte*) cursor#3 zp ptr byte:2
-(byte*) cursor#5 zp ptr byte:2
+(byte*) cursor#1 zp ptr byte:2 8.25
+(byte*) cursor#2 zp ptr byte:2 11.0
+(byte*) cursor#3 zp ptr byte:2 11.0
+(byte*) cursor#5 zp ptr byte:2 16.5
 (byte) e
-(byte) e#1 zp byte:5
-(byte) e#2 zp byte:5
-(byte) e#3 zp byte:5
-(byte) e#5 zp byte:5
+(byte) e#1 zp byte:5 11.0
+(byte) e#2 zp byte:5 22.0
+(byte) e#3 zp byte:5 5.5
+(byte) e#5 zp byte:5 16.5
 (byte) x
-(byte) x#1 zp byte:4
-(byte) x#2 zp byte:4
+(byte) x#1 zp byte:4 3.666666666666667
+(byte) x#2 zp byte:4 11.0
 (byte) x0
 (byte) x1
 (byte) xd
 (byte) y
-(byte) y#1 zp byte:6
-(byte) y#2 zp byte:6
-(byte) y#4 zp byte:6
+(byte) y#1 zp byte:6 7.333333333333333
+(byte) y#2 zp byte:6 5.5
+(byte) y#4 zp byte:6 16.5
 (byte) y0
 (byte) y1
 (byte) yd

src/main/java/dk/camelot64/kickc/test/ref/bresenham.sym

@@ -6,25 +6,30 @@
 (byte[1000]) SCREEN
 (byte) STAR
 (byte*) cursor
-(byte*) cursor#1 zp ptr byte:2
-(byte*) cursor#2 zp ptr byte:2
-(byte*) cursor#3 zp ptr byte:2
-(byte*) cursor#5 zp ptr byte:2
+(byte*) cursor#1 zp ptr byte:2 8.25
+(byte*) cursor#2 zp ptr byte:2 11.0
+(byte*) cursor#3 zp ptr byte:2 11.0
+(byte*) cursor#5 zp ptr byte:2 16.5
 (byte) e
-(byte) e#1 zp byte:5
-(byte) e#2 zp byte:5
-(byte) e#3 zp byte:5
-(byte) e#5 zp byte:5
+(byte) e#1 zp byte:5 11.0
+(byte) e#2 zp byte:5 22.0
+(byte) e#3 zp byte:5 5.5
+(byte) e#5 zp byte:5 16.5
 (byte) x
-(byte) x#1 zp byte:4
-(byte) x#2 zp byte:4
+(byte) x#1 zp byte:4 3.666666666666667
+(byte) x#2 zp byte:4 11.0
 (byte) x0
 (byte) x1
 (byte) xd
 (byte) y
-(byte) y#1 zp byte:6
-(byte) y#2 zp byte:6
-(byte) y#4 zp byte:6
+(byte) y#1 zp byte:6 7.333333333333333
+(byte) y#2 zp byte:6 5.5
+(byte) y#4 zp byte:6 16.5
 (byte) y0
 (byte) y1
 (byte) yd
+
+zp ptr byte:2 [ cursor#3 cursor#5 cursor#1 cursor#2 ]
+zp byte:4 [ x#2 x#1 ]
+zp byte:5 [ e#3 e#5 e#1 e#2 ]
+zp byte:6 [ y#2 y#4 y#1 ]

src/main/java/dk/camelot64/kickc/test/ref/flipper-rex2.log

@@ -183,7 +183,6 @@ SYMBOLS
 (byte) flip::i
 (byte) flip::r
 (byte) flip::srcIdx
-
 (void()) main()
 (void~) main::$0
 (byte~) main::$1
@@ -199,7 +198,6 @@ SYMBOLS
 (label) main::@4
 (label) main::@return
 (byte) main::c
-
 (void()) plot()
 (byte~) plot::$0
 (byte*~) plot::$1
@@ -215,14 +213,12 @@ SYMBOLS
 (byte*) plot::line
 (byte) plot::x
 (byte) plot::y
-
 (void()) prepare()
 (boolean~) prepare::$0
 (label) prepare::@1
 (label) prepare::@return
 (byte) prepare::i
 
-
 INITIAL CONTROL FLOW GRAPH
 @BEGIN: from
   (byte[1000]) SCREEN ← (word) 1024
@@ -3884,6 +3880,76 @@ 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 ]
+
+VARIABLE REGISTER WEIGHTS
+(byte*) RASTER
+(byte[1000]) SCREEN
+(byte[256]) buffer1
+(byte[256]) buffer2
+(void()) flip()
+(byte~) flip::$0 2002.0
+(byte~) flip::$4 202.0
+(byte) flip::c
+(byte) flip::c#1 1501.5
+(byte) flip::c#2 400.4
+(byte) flip::dstIdx
+(byte) flip::dstIdx#1 701.0
+(byte) flip::dstIdx#2 67.33333333333333
+(byte) flip::dstIdx#3 776.0
+(byte) flip::dstIdx#5 202.0
+(byte) flip::i
+(byte) flip::i#1 151.5
+(byte) flip::i#2 134.66666666666666
+(byte) flip::r
+(byte) flip::r#1 151.5
+(byte) flip::r#2 22.444444444444443
+(byte) flip::srcIdx
+(byte) flip::srcIdx#1 300.42857142857144
+(byte) flip::srcIdx#2 1034.6666666666667
+(byte) flip::srcIdx#3 202.0
+(void()) main()
+(byte~) main::$1 2002.0
+(byte~) main::$3 2002.0
+(byte) main::c
+(byte) main::c#1 151.5
+(byte) main::c#2 40.4
+(void()) plot()
+(byte~) plot::$3 2002.0
+(byte) plot::i
+(byte) plot::i#1 350.5
+(byte) plot::i#2 1034.6666666666667
+(byte) plot::i#3 202.0
+(byte*) plot::line
+(byte*) plot::line#1 67.33333333333333
+(byte*) plot::line#2 171.85714285714283
+(byte) plot::x
+(byte) plot::x#1 1501.5
+(byte) plot::x#2 750.75
+(byte) plot::y
+(byte) plot::y#1 151.5
+(byte) plot::y#2 25.25
+(void()) prepare()
+(byte) prepare::i
+(byte) prepare::i#1 16.5
+(byte) prepare::i#2 22.0
+
+zp byte:2 [ main::c#2 main::c#1 ]
+zp ptr byte:3 [ plot::line#2 plot::line#1 ]
+zp byte:5 [ plot::y#2 plot::y#1 ]
+zp byte:6 [ plot::i#2 plot::i#3 plot::i#1 ]
+zp byte:7 [ plot::x#2 plot::x#1 ]
+zp byte:8 [ flip::r#2 flip::r#1 ]
+zp byte:9 [ flip::srcIdx#2 flip::srcIdx#3 flip::srcIdx#1 ]
+zp byte:10 [ flip::dstIdx#3 flip::dstIdx#5 flip::dstIdx#2 flip::dstIdx#1 ]
+zp byte:11 [ flip::c#2 flip::c#1 ]
+zp byte:12 [ flip::i#2 flip::i#1 ]
+zp byte:13 [ prepare::i#2 prepare::i#1 ]
+zp byte:14 [ main::$1 ]
+zp byte:15 [ main::$3 ]
+zp byte:16 [ plot::$3 ]
+zp byte:17 [ flip::$0 ]
+zp byte:18 [ flip::$4 ]
+
 Coalescing zero page register [ zp byte:2 [ main::c#2 main::c#1 ] ] with [ zp byte:5 [ plot::y#2 plot::y#1 ] ]
 Coalescing zero page register [ zp byte:2 [ main::c#2 main::c#1 plot::y#2 plot::y#1 ] ] with [ zp byte:8 [ flip::r#2 flip::r#1 ] ]
 Coalescing zero page register [ zp byte:2 [ main::c#2 main::c#1 plot::y#2 plot::y#1 flip::r#2 flip::r#1 ] ] with [ zp byte:12 [ flip::i#2 flip::i#1 ] ]
@@ -4794,35 +4860,34 @@ FINAL SYMBOL TABLE
 (byte[256]) buffer1
 (byte[256]) buffer2
 (void()) flip()
-(byte~) flip::$0 zp byte:8
-(byte~) flip::$4 zp byte:5
+(byte~) flip::$0 zp byte:8 2002.0
+(byte~) flip::$4 zp byte:5 202.0
 (label) flip::@1
 (label) flip::@2
 (label) flip::@3
 (label) flip::@4
 (label) flip::@return
 (byte) flip::c
-(byte) flip::c#1 zp byte:7
-(byte) flip::c#2 zp byte:7
+(byte) flip::c#1 zp byte:7 1501.5
+(byte) flip::c#2 zp byte:7 400.4
 (byte) flip::dstIdx
-(byte) flip::dstIdx#1 zp byte:6
-(byte) flip::dstIdx#2 zp byte:6
-(byte) flip::dstIdx#3 zp byte:6
-(byte) flip::dstIdx#5 zp byte:6
+(byte) flip::dstIdx#1 zp byte:6 701.0
+(byte) flip::dstIdx#2 zp byte:6 67.33333333333333
+(byte) flip::dstIdx#3 zp byte:6 776.0
+(byte) flip::dstIdx#5 zp byte:6 202.0
 (byte) flip::i
-(byte) flip::i#1 zp byte:2
-(byte) flip::i#2 zp byte:2
+(byte) flip::i#1 zp byte:2 151.5
+(byte) flip::i#2 zp byte:2 134.66666666666666
 (byte) flip::r
-(byte) flip::r#1 zp byte:2
-(byte) flip::r#2 zp byte:2
+(byte) flip::r#1 zp byte:2 151.5
+(byte) flip::r#2 zp byte:2 22.444444444444443
 (byte) flip::srcIdx
-(byte) flip::srcIdx#1 zp byte:5
-(byte) flip::srcIdx#2 zp byte:5
-(byte) flip::srcIdx#3 zp byte:5
-
+(byte) flip::srcIdx#1 zp byte:5 300.42857142857144
+(byte) flip::srcIdx#2 zp byte:5 1034.6666666666667
+(byte) flip::srcIdx#3 zp byte:5 202.0
 (void()) main()
-(byte~) main::$1 zp byte:5
-(byte~) main::$3 zp byte:5
+(byte~) main::$1 zp byte:5 2002.0
+(byte~) main::$3 zp byte:5 2002.0
 (label) main::@10
 (label) main::@11
 (label) main::@3
@@ -4831,36 +4896,33 @@ FINAL SYMBOL TABLE
 (label) main::@7
 (label) main::@return
 (byte) main::c
-(byte) main::c#1 zp byte:2
-(byte) main::c#2 zp byte:2
-
+(byte) main::c#1 zp byte:2 151.5
+(byte) main::c#2 zp byte:2 40.4
 (void()) plot()
-(byte~) plot::$3 zp byte:7
+(byte~) plot::$3 zp byte:7 2002.0
 (label) plot::@1
 (label) plot::@2
 (label) plot::@3
 (label) plot::@return
 (byte) plot::i
-(byte) plot::i#1 zp byte:5
-(byte) plot::i#2 zp byte:5
-(byte) plot::i#3 zp byte:5
+(byte) plot::i#1 zp byte:5 350.5
+(byte) plot::i#2 zp byte:5 1034.6666666666667
+(byte) plot::i#3 zp byte:5 202.0
 (byte*) plot::line
-(byte*) plot::line#1 zp ptr byte:3
-(byte*) plot::line#2 zp ptr byte:3
+(byte*) plot::line#1 zp ptr byte:3 67.33333333333333
+(byte*) plot::line#2 zp ptr byte:3 171.85714285714283
 (byte) plot::x
-(byte) plot::x#1 zp byte:6
-(byte) plot::x#2 zp byte:6
+(byte) plot::x#1 zp byte:6 1501.5
+(byte) plot::x#2 zp byte:6 750.75
 (byte) plot::y
-(byte) plot::y#1 zp byte:2
-(byte) plot::y#2 zp byte:2
-
+(byte) plot::y#1 zp byte:2 151.5
+(byte) plot::y#2 zp byte:2 25.25
 (void()) prepare()
 (label) prepare::@1
 (label) prepare::@return
 (byte) prepare::i
-(byte) prepare::i#1 zp byte:2
-(byte) prepare::i#2 zp byte:2
-
+(byte) prepare::i#1 zp byte:2 16.5
+(byte) prepare::i#2 zp byte:2 22.0
 
 zp byte:2 [ main::c#2 main::c#1 plot::y#2 plot::y#1 flip::r#2 flip::r#1 flip::i#2 flip::i#1 prepare::i#2 prepare::i#1 ]
 zp ptr byte:3 [ plot::line#2 plot::line#1 ]

src/main/java/dk/camelot64/kickc/test/ref/flipper-rex2.sym

@@ -5,35 +5,34 @@
 (byte[256]) buffer1
 (byte[256]) buffer2
 (void()) flip()
-(byte~) flip::$0 zp byte:8
-(byte~) flip::$4 zp byte:5
+(byte~) flip::$0 zp byte:8 2002.0
+(byte~) flip::$4 zp byte:5 202.0
 (label) flip::@1
 (label) flip::@2
 (label) flip::@3
 (label) flip::@4
 (label) flip::@return
 (byte) flip::c
-(byte) flip::c#1 zp byte:7
-(byte) flip::c#2 zp byte:7
+(byte) flip::c#1 zp byte:7 1501.5
+(byte) flip::c#2 zp byte:7 400.4
 (byte) flip::dstIdx
-(byte) flip::dstIdx#1 zp byte:6
-(byte) flip::dstIdx#2 zp byte:6
-(byte) flip::dstIdx#3 zp byte:6
-(byte) flip::dstIdx#5 zp byte:6
+(byte) flip::dstIdx#1 zp byte:6 701.0
+(byte) flip::dstIdx#2 zp byte:6 67.33333333333333
+(byte) flip::dstIdx#3 zp byte:6 776.0
+(byte) flip::dstIdx#5 zp byte:6 202.0
 (byte) flip::i
-(byte) flip::i#1 zp byte:2
-(byte) flip::i#2 zp byte:2
+(byte) flip::i#1 zp byte:2 151.5
+(byte) flip::i#2 zp byte:2 134.66666666666666
 (byte) flip::r
-(byte) flip::r#1 zp byte:2
-(byte) flip::r#2 zp byte:2
+(byte) flip::r#1 zp byte:2 151.5
+(byte) flip::r#2 zp byte:2 22.444444444444443
 (byte) flip::srcIdx
-(byte) flip::srcIdx#1 zp byte:5
-(byte) flip::srcIdx#2 zp byte:5
-(byte) flip::srcIdx#3 zp byte:5
-
+(byte) flip::srcIdx#1 zp byte:5 300.42857142857144
+(byte) flip::srcIdx#2 zp byte:5 1034.6666666666667
+(byte) flip::srcIdx#3 zp byte:5 202.0
 (void()) main()
-(byte~) main::$1 zp byte:5
-(byte~) main::$3 zp byte:5
+(byte~) main::$1 zp byte:5 2002.0
+(byte~) main::$3 zp byte:5 2002.0
 (label) main::@10
 (label) main::@11
 (label) main::@3
@@ -42,33 +41,37 @@
 (label) main::@7
 (label) main::@return
 (byte) main::c
-(byte) main::c#1 zp byte:2
-(byte) main::c#2 zp byte:2
-
+(byte) main::c#1 zp byte:2 151.5
+(byte) main::c#2 zp byte:2 40.4
 (void()) plot()
-(byte~) plot::$3 zp byte:7
+(byte~) plot::$3 zp byte:7 2002.0
 (label) plot::@1
 (label) plot::@2
 (label) plot::@3
 (label) plot::@return
 (byte) plot::i
-(byte) plot::i#1 zp byte:5
-(byte) plot::i#2 zp byte:5
-(byte) plot::i#3 zp byte:5
+(byte) plot::i#1 zp byte:5 350.5
+(byte) plot::i#2 zp byte:5 1034.6666666666667
+(byte) plot::i#3 zp byte:5 202.0
 (byte*) plot::line
-(byte*) plot::line#1 zp ptr byte:3
-(byte*) plot::line#2 zp ptr byte:3
+(byte*) plot::line#1 zp ptr byte:3 67.33333333333333
+(byte*) plot::line#2 zp ptr byte:3 171.85714285714283
 (byte) plot::x
-(byte) plot::x#1 zp byte:6
-(byte) plot::x#2 zp byte:6
+(byte) plot::x#1 zp byte:6 1501.5
+(byte) plot::x#2 zp byte:6 750.75
 (byte) plot::y
-(byte) plot::y#1 zp byte:2
-(byte) plot::y#2 zp byte:2
-
+(byte) plot::y#1 zp byte:2 151.5
+(byte) plot::y#2 zp byte:2 25.25
 (void()) prepare()
 (label) prepare::@1
 (label) prepare::@return
 (byte) prepare::i
-(byte) prepare::i#1 zp byte:2
-(byte) prepare::i#2 zp byte:2
+(byte) prepare::i#1 zp byte:2 16.5
+(byte) prepare::i#2 zp byte:2 22.0
 
+zp byte:2 [ main::c#2 main::c#1 plot::y#2 plot::y#1 flip::r#2 flip::r#1 flip::i#2 flip::i#1 prepare::i#2 prepare::i#1 ]
+zp ptr byte:3 [ plot::line#2 plot::line#1 ]
+zp byte:6 [ plot::i#2 plot::i#3 plot::i#1 flip::srcIdx#2 flip::srcIdx#3 flip::srcIdx#1 main::$1 main::$3 flip::$4 ]
+zp byte:7 [ plot::x#2 plot::x#1 flip::dstIdx#3 flip::dstIdx#5 flip::dstIdx#2 flip::dstIdx#1 ]
+zp byte:11 [ flip::c#2 flip::c#1 plot::$3 ]
+zp byte:17 [ flip::$0 ]

src/main/java/dk/camelot64/kickc/test/ref/loopmin.log

@@ -371,6 +371,19 @@ Complete equivalence classes
 [ 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 ]
+
+VARIABLE REGISTER WEIGHTS
+(byte) i
+(byte) i#1 16.5
+(byte) i#2 11.0
+(byte) s
+(byte) s#1 22.0
+(byte) s#2 16.5
+(byte) s#4 11.0
+
+zp byte:2 [ i#2 i#1 ]
+zp byte:3 [ s#2 s#4 s#1 ]
+
 Re-allocated ZP register from zp byte:2 to zp byte:2
 Re-allocated ZP register from zp byte:3 to zp byte:3
 INITIAL ASM
@@ -505,12 +518,12 @@ FINAL SYMBOL TABLE
 (label) @BEGIN
 (label) @END
 (byte) i
-(byte) i#1 zp byte:2
-(byte) i#2 zp byte:2
+(byte) i#1 zp byte:2 16.5
+(byte) i#2 zp byte:2 11.0
 (byte) s
-(byte) s#1 zp byte:3
-(byte) s#2 zp byte:3
-(byte) s#4 zp byte:3
+(byte) s#1 zp byte:3 22.0
+(byte) s#2 zp byte:3 16.5
+(byte) s#4 zp byte:3 11.0
 
 zp byte:2 [ i#2 i#1 ]
 zp byte:3 [ s#2 s#4 s#1 ]

src/main/java/dk/camelot64/kickc/test/ref/loopmin.sym

@@ -4,9 +4,12 @@
 (label) @BEGIN
 (label) @END
 (byte) i
-(byte) i#1 zp byte:2
-(byte) i#2 zp byte:2
+(byte) i#1 zp byte:2 16.5
+(byte) i#2 zp byte:2 11.0
 (byte) s
-(byte) s#1 zp byte:3
-(byte) s#2 zp byte:3
-(byte) s#4 zp byte:3
+(byte) s#1 zp byte:3 22.0
+(byte) s#2 zp byte:3 16.5
+(byte) s#4 zp byte:3 11.0
+
+zp byte:2 [ i#2 i#1 ]
+zp byte:3 [ s#2 s#4 s#1 ]

src/main/java/dk/camelot64/kickc/test/ref/loopnest.log

@@ -51,14 +51,12 @@ SYMBOLS
 (label) main::@1
 (label) main::@return
 (byte) main::i
-
 (void()) nest()
 (boolean~) nest::$0
 (label) nest::@1
 (label) nest::@return
 (byte) nest::j
 
-
 INITIAL CONTROL FLOW GRAPH
 @BEGIN: from
   (byte*) SCREEN ← (word) 1024
@@ -721,6 +719,21 @@ Complete equivalence classes
 [ 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 ]
+
+VARIABLE REGISTER WEIGHTS
+(byte*) SCREEN
+(void()) main()
+(byte) main::i
+(byte) main::i#1 16.5
+(byte) main::i#2 3.142857142857143
+(void()) nest()
+(byte) nest::j
+(byte) nest::j#1 151.5
+(byte) nest::j#2 151.5
+
+zp byte:2 [ main::i#2 main::i#1 ]
+zp byte:3 [ nest::j#2 nest::j#1 ]
+
 Re-allocated ZP register from zp byte:2 to zp byte:2
 Re-allocated ZP register from zp byte:3 to zp byte:3
 INITIAL ASM
@@ -872,16 +885,14 @@ FINAL SYMBOL TABLE
 (label) main::@3
 (label) main::@return
 (byte) main::i
-(byte) main::i#1 zp byte:2
-(byte) main::i#2 zp byte:2
-
+(byte) main::i#1 zp byte:2 16.5
+(byte) main::i#2 zp byte:2 3.142857142857143
 (void()) nest()
 (label) nest::@1
 (label) nest::@return
 (byte) nest::j
-(byte) nest::j#1 zp byte:3
-(byte) nest::j#2 zp byte:3
-
+(byte) nest::j#1 zp byte:3 151.5
+(byte) nest::j#2 zp byte:3 151.5
 
 zp byte:2 [ main::i#2 main::i#1 ]
 zp byte:3 [ nest::j#2 nest::j#1 ]

src/main/java/dk/camelot64/kickc/test/ref/loopnest.sym

@@ -6,16 +6,14 @@
 (label) main::@3
 (label) main::@return
 (byte) main::i
-(byte) main::i#1 zp byte:2
-(byte) main::i#2 zp byte:2
-
+(byte) main::i#1 zp byte:2 16.5
+(byte) main::i#2 zp byte:2 3.142857142857143
 (void()) nest()
 (label) nest::@1
 (label) nest::@return
 (byte) nest::j
-(byte) nest::j#1 zp byte:3
-(byte) nest::j#2 zp byte:3
-
+(byte) nest::j#1 zp byte:3 151.5
+(byte) nest::j#2 zp byte:3 151.5
 
 zp byte:2 [ main::i#2 main::i#1 ]
 zp byte:3 [ nest::j#2 nest::j#1 ]

src/main/java/dk/camelot64/kickc/test/ref/loopnest2.log

@@ -99,7 +99,6 @@ SYMBOLS
 (label) main::@return
 (byte) main::i
 (byte) main::j
-
 (void()) nest1()
 (void~) nest1::$0
 (boolean~) nest1::$1
@@ -109,7 +108,6 @@ SYMBOLS
 (label) nest1::@return
 (byte) nest1::i
 (byte) nest1::j
-
 (void()) nest2()
 (boolean~) nest2::$0
 (boolean~) nest2::$1
@@ -119,7 +117,6 @@ SYMBOLS
 (byte) nest2::i
 (byte) nest2::j
 
-
 INITIAL CONTROL FLOW GRAPH
 @BEGIN: from
   (byte*) SCREEN ← (word) 1024
@@ -1820,6 +1817,38 @@ 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 ]
+
+VARIABLE REGISTER WEIGHTS
+(byte*) SCREEN
+(void()) main()
+(byte) main::i
+(byte) main::i#1 16.5
+(byte) main::i#2 1.0476190476190477
+(byte) main::j
+(byte) main::j#1 151.5
+(byte) main::j#2 11.222222222222221
+(void()) nest1()
+(byte) nest1::i
+(byte) nest1::i#1 1501.5
+(byte) nest1::i#2 154.0
+(byte) nest1::j
+(byte) nest1::j#1 15001.5
+(byte) nest1::j#2 2000.2
+(void()) nest2()
+(byte) nest2::i
+(byte) nest2::i#1 150001.5
+(byte) nest2::i#2 40000.4
+(byte) nest2::j
+(byte) nest2::j#1 1500001.5
+(byte) nest2::j#2 1500001.5
+
+zp byte:2 [ main::i#2 main::i#1 ]
+zp byte:3 [ main::j#2 main::j#1 ]
+zp byte:4 [ nest1::i#2 nest1::i#1 ]
+zp byte:5 [ nest1::j#2 nest1::j#1 ]
+zp byte:6 [ nest2::i#2 nest2::i#1 ]
+zp byte:7 [ nest2::j#2 nest2::j#1 ]
+
 Re-allocated ZP register from zp byte:2 to zp byte:2
 Re-allocated ZP register from zp byte:3 to zp byte:3
 Re-allocated ZP register from zp byte:4 to zp byte:4
@@ -2175,12 +2204,11 @@ FINAL SYMBOL TABLE
 (label) main::@5
 (label) main::@return
 (byte) main::i
-(byte) main::i#1 zp byte:2
-(byte) main::i#2 zp byte:2
+(byte) main::i#1 zp byte:2 16.5
+(byte) main::i#2 zp byte:2 1.0476190476190477
 (byte) main::j
-(byte) main::j#1 zp byte:3
-(byte) main::j#2 zp byte:3
-
+(byte) main::j#1 zp byte:3 151.5
+(byte) main::j#2 zp byte:3 11.222222222222221
 (void()) nest1()
 (label) nest1::@1
 (label) nest1::@2
@@ -2188,24 +2216,22 @@ FINAL SYMBOL TABLE
 (label) nest1::@5
 (label) nest1::@return
 (byte) nest1::i
-(byte) nest1::i#1 zp byte:4
-(byte) nest1::i#2 zp byte:4
+(byte) nest1::i#1 zp byte:4 1501.5
+(byte) nest1::i#2 zp byte:4 154.0
 (byte) nest1::j
-(byte) nest1::j#1 zp byte:5
-(byte) nest1::j#2 zp byte:5
-
+(byte) nest1::j#1 zp byte:5 15001.5
+(byte) nest1::j#2 zp byte:5 2000.2
 (void()) nest2()
 (label) nest2::@1
 (label) nest2::@2
 (label) nest2::@3
 (label) nest2::@return
 (byte) nest2::i
-(byte) nest2::i#1 zp byte:6
-(byte) nest2::i#2 zp byte:6
+(byte) nest2::i#1 zp byte:6 150001.5
+(byte) nest2::i#2 zp byte:6 40000.4
 (byte) nest2::j
-(byte) nest2::j#1 zp byte:7
-(byte) nest2::j#2 zp byte:7
-
+(byte) nest2::j#1 zp byte:7 1500001.5
+(byte) nest2::j#2 zp byte:7 1500001.5
 
 zp byte:2 [ main::i#2 main::i#1 ]
 zp byte:3 [ main::j#2 main::j#1 ]

src/main/java/dk/camelot64/kickc/test/ref/loopnest2.sym

@@ -8,12 +8,11 @@
 (label) main::@5
 (label) main::@return
 (byte) main::i
-(byte) main::i#1 zp byte:2
-(byte) main::i#2 zp byte:2
+(byte) main::i#1 zp byte:2 16.5
+(byte) main::i#2 zp byte:2 1.0476190476190477
 (byte) main::j
-(byte) main::j#1 zp byte:3
-(byte) main::j#2 zp byte:3
-
+(byte) main::j#1 zp byte:3 151.5
+(byte) main::j#2 zp byte:3 11.222222222222221
 (void()) nest1()
 (label) nest1::@1
 (label) nest1::@2
@@ -21,24 +20,22 @@
 (label) nest1::@5
 (label) nest1::@return
 (byte) nest1::i
-(byte) nest1::i#1 zp byte:4
-(byte) nest1::i#2 zp byte:4
+(byte) nest1::i#1 zp byte:4 1501.5
+(byte) nest1::i#2 zp byte:4 154.0
 (byte) nest1::j
-(byte) nest1::j#1 zp byte:5
-(byte) nest1::j#2 zp byte:5
-
+(byte) nest1::j#1 zp byte:5 15001.5
+(byte) nest1::j#2 zp byte:5 2000.2
 (void()) nest2()
 (label) nest2::@1
 (label) nest2::@2
 (label) nest2::@3
 (label) nest2::@return
 (byte) nest2::i
-(byte) nest2::i#1 zp byte:6
-(byte) nest2::i#2 zp byte:6
+(byte) nest2::i#1 zp byte:6 150001.5
+(byte) nest2::i#2 zp byte:6 40000.4
 (byte) nest2::j
-(byte) nest2::j#1 zp byte:7
-(byte) nest2::j#2 zp byte:7
-
+(byte) nest2::j#1 zp byte:7 1500001.5
+(byte) nest2::j#2 zp byte:7 1500001.5
 
 zp byte:2 [ main::i#2 main::i#1 ]
 zp byte:3 [ main::j#2 main::j#1 ]

src/main/java/dk/camelot64/kickc/test/ref/loopsplit.log

@@ -395,6 +395,19 @@ Complete equivalence classes
 [ s#3 s#1 s#2 ]
 Allocated zp byte:2 to zp byte:2 [ i#2 i#1 ]
 Allocated zp byte:3 to zp byte:3 [ s#3 s#1 s#2 ]
+
+VARIABLE REGISTER WEIGHTS
+(byte) i
+(byte) i#1 11.0
+(byte) i#2 33.0
+(byte) s
+(byte) s#1 22.0
+(byte) s#2 22.0
+(byte) s#3 11.0
+
+zp byte:2 [ i#2 i#1 ]
+zp byte:3 [ s#3 s#1 s#2 ]
+
 Re-allocated ZP register from zp byte:2 to zp byte:2
 Re-allocated ZP register from zp byte:3 to zp byte:3
 INITIAL ASM
@@ -527,12 +540,12 @@ FINAL SYMBOL TABLE
 (label) @BEGIN
 (label) @END
 (byte) i
-(byte) i#1 zp byte:2
-(byte) i#2 zp byte:2
+(byte) i#1 zp byte:2 11.0
+(byte) i#2 zp byte:2 33.0
 (byte) s
-(byte) s#1 zp byte:3
-(byte) s#2 zp byte:3
-(byte) s#3 zp byte:3
+(byte) s#1 zp byte:3 22.0
+(byte) s#2 zp byte:3 22.0
+(byte) s#3 zp byte:3 11.0
 
 zp byte:2 [ i#2 i#1 ]
 zp byte:3 [ s#3 s#1 s#2 ]

src/main/java/dk/camelot64/kickc/test/ref/loopsplit.sym

@@ -5,9 +5,12 @@
 (label) @BEGIN
 (label) @END
 (byte) i
-(byte) i#1 zp byte:2
-(byte) i#2 zp byte:2
+(byte) i#1 zp byte:2 11.0
+(byte) i#2 zp byte:2 33.0
 (byte) s
-(byte) s#1 zp byte:3
-(byte) s#2 zp byte:3
-(byte) s#3 zp byte:3
+(byte) s#1 zp byte:3 22.0
+(byte) s#2 zp byte:3 22.0
+(byte) s#3 zp byte:3 11.0
+
+zp byte:2 [ i#2 i#1 ]
+zp byte:3 [ s#3 s#1 s#2 ]

src/main/java/dk/camelot64/kickc/test/ref/minus.log

@@ -291,6 +291,18 @@ Complete equivalence classes
 [ $0 $1 ]
 Allocated zp byte:2 to zp byte:2 [ i#2 i#1 ]
 Allocated zp byte:3 to zp byte:3 [ $0 $1 ]
+
+VARIABLE REGISTER WEIGHTS
+(byte~) $0 22.0
+(byte~) $1 22.0
+(byte) i
+(byte) i#1 16.5
+(byte) i#2 11.0
+(byte[16]) p
+
+zp byte:2 [ i#2 i#1 ]
+zp byte:3 [ $0 $1 ]
+
 Re-allocated ZP register from zp byte:2 to zp byte:2
 Re-allocated ZP register from zp byte:3 to zp byte:3
 INITIAL ASM
@@ -396,14 +408,14 @@ B1:
 BEND:
 
 FINAL SYMBOL TABLE
-(byte~) $0 zp byte:3
-(byte~) $1 zp byte:3
+(byte~) $0 zp byte:3 22.0
+(byte~) $1 zp byte:3 22.0
 (label) @1
 (label) @BEGIN
 (label) @END
 (byte) i
-(byte) i#1 zp byte:2
-(byte) i#2 zp byte:2
+(byte) i#1 zp byte:2 16.5
+(byte) i#2 zp byte:2 11.0
 (byte[16]) p
 
 zp byte:2 [ i#2 i#1 ]

src/main/java/dk/camelot64/kickc/test/ref/minus.sym

@@ -1,9 +1,12 @@
-(byte~) $0 zp byte:3
-(byte~) $1 zp byte:3
+(byte~) $0 zp byte:3 22.0
+(byte~) $1 zp byte:3 22.0
 (label) @1
 (label) @BEGIN
 (label) @END
 (byte) i
-(byte) i#1 zp byte:2
-(byte) i#2 zp byte:2
+(byte) i#1 zp byte:2 16.5
+(byte) i#2 zp byte:2 11.0
 (byte[16]) p
+
+zp byte:2 [ i#2 i#1 ]
+zp byte:3 [ $0 $1 ]

src/main/java/dk/camelot64/kickc/test/ref/summin.log

@@ -35,7 +35,6 @@ SYMBOLS
 (byte) sum::b
 (byte) sum::return
 
-
 INITIAL CONTROL FLOW GRAPH
 @BEGIN: from
   (byte~) $0 ← call sum (byte) 1 (byte) 2 
@@ -370,6 +369,27 @@ Allocated zp byte:2 to zp byte:2 [ sum::a#2 sum::return#0 ]
 Allocated zp byte:3 to zp byte:3 [ sum::b#2 ]
 Allocated zp byte:4 to zp byte:4 [ s1#0 s3#0 ]
 Allocated zp byte:5 to zp byte:5 [ s2#0 ]
+
+VARIABLE REGISTER WEIGHTS
+(byte) s1
+(byte) s1#0 0.5714285714285714
+(byte) s2
+(byte) s2#0 4.0
+(byte) s3
+(byte) s3#0 Infinity
+(byte()) sum((byte) sum::a , (byte) sum::b)
+(byte) sum::a
+(byte) sum::a#2 2.0
+(byte) sum::b
+(byte) sum::b#2 2.0
+(byte) sum::return
+(byte) sum::return#0 1.2000000000000002
+
+zp byte:2 [ sum::a#2 sum::return#0 ]
+zp byte:3 [ sum::b#2 ]
+zp byte:4 [ s1#0 s3#0 ]
+zp byte:5 [ s2#0 ]
+
 Coalescing zero page register [ zp byte:2 [ sum::a#2 sum::return#0 ] ] with [ zp byte:5 [ s2#0 ] ]
 Re-allocated ZP register from zp byte:2 to zp byte:2
 Re-allocated ZP register from zp byte:3 to zp byte:3
@@ -467,20 +487,19 @@ FINAL SYMBOL TABLE
 (label) @BEGIN
 (label) @END
 (byte) s1
-(byte) s1#0 zp byte:4
+(byte) s1#0 zp byte:4 0.5714285714285714
 (byte) s2
-(byte) s2#0 zp byte:2
+(byte) s2#0 zp byte:2 4.0
 (byte) s3
-(byte) s3#0 zp byte:4
+(byte) s3#0 zp byte:4 Infinity
 (byte()) sum((byte) sum::a , (byte) sum::b)
 (label) sum::@return
 (byte) sum::a
-(byte) sum::a#2 zp byte:2
+(byte) sum::a#2 zp byte:2 2.0
 (byte) sum::b
-(byte) sum::b#2 zp byte:3
+(byte) sum::b#2 zp byte:3 2.0
 (byte) sum::return
-(byte) sum::return#0 zp byte:2
-
+(byte) sum::return#0 zp byte:2 1.2000000000000002
 
 zp byte:2 [ sum::a#2 sum::return#0 s2#0 ]
 zp byte:3 [ sum::b#2 ]

src/main/java/dk/camelot64/kickc/test/ref/summin.sym

@@ -3,20 +3,19 @@
 (label) @BEGIN
 (label) @END
 (byte) s1
-(byte) s1#0 zp byte:4
+(byte) s1#0 zp byte:4 0.5714285714285714
 (byte) s2
-(byte) s2#0 zp byte:2
+(byte) s2#0 zp byte:2 4.0
 (byte) s3
-(byte) s3#0 zp byte:4
+(byte) s3#0 zp byte:4 Infinity
 (byte()) sum((byte) sum::a , (byte) sum::b)
 (label) sum::@return
 (byte) sum::a
-(byte) sum::a#2 zp byte:2
+(byte) sum::a#2 zp byte:2 2.0
 (byte) sum::b
-(byte) sum::b#2 zp byte:3
+(byte) sum::b#2 zp byte:3 2.0
 (byte) sum::return
-(byte) sum::return#0 zp byte:2
-
+(byte) sum::return#0 zp byte:2 1.2000000000000002
 
 zp byte:2 [ sum::a#2 sum::return#0 s2#0 ]
 zp byte:3 [ sum::b#2 ]