Implemented fib - and fixed alias elimination issue

src/dk/camelot64/kickc/icl/Pass2AliasElimination.java

@@ -1,6 +1,7 @@
 package dk.camelot64.kickc.icl;
 
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.Map;
 
 /** Compiler Pass eliminating alias assignments */
@@ -26,11 +27,48 @@ public class Pass2AliasElimination extends Pass2Optimization {
       return (aliases.size()>0);
    }
 
+   private Map<Variable, Variable> findAliases() {
+      Map<Variable, Variable> candidates = findAliasesCandidates();
+      cleanupCandidates(candidates);
+      return candidates;
+   }
+
+   // Remove all candidates that are used after assignment in phi blocks
+   private void cleanupCandidates(Map<Variable, Variable> candidates) {
+      Iterator<Variable> aliasIt = candidates.keySet().iterator();
+      while (aliasIt.hasNext()) {
+         final Variable alias  = aliasIt.next();
+         final Variable variable = candidates.get(alias);
+         final Boolean[] rMatch = {false};
+         final Boolean[] lMatch = {false};
+         ControlFlowGraphBaseVisitor<Void> candidateEliminator = new ControlFlowGraphBaseVisitor<Void>() {
+            @Override
+            public Void visitPhi(StatementPhi phi) {
+               for (StatementPhi.PreviousSymbol previousSymbol : phi.getPreviousVersions()) {
+                  if(previousSymbol.getRValue().equals(variable)) {
+                     rMatch[0] = true;
+                     break;
+                  }
+               }
+               if(phi.getLValue().equals(alias)) {
+                  lMatch[0] = true;
+               }
+               return null;
+            }
+         };
+         candidateEliminator.visitGraph(getGraph());
+         if(rMatch[0] && lMatch[0]) {
+            System.out.println("Alias candidate removed " + alias + " " + variable);
+            aliasIt.remove();
+         }
+      }
+   }
+
    /**
     * Find variables that have constant values.
     * @return Map from Variable to the Constant value
     */
-   private Map<Variable, Variable> findAliases() {
+   private Map<Variable, Variable> findAliasesCandidates() {
       final Map<Variable, Variable> aliases = new HashMap<>();
       ControlFlowGraphBaseVisitor<Void> visitor = new ControlFlowGraphBaseVisitor<Void>() {
          @Override

src/dk/camelot64/kickc/icl/Pass4CodeGeneration.java

@@ -56,7 +56,7 @@ public class Pass4CodeGeneration {
          asm.addAsm("  // " + statement + "  //  " + asmFragment.getSignature());
          asmFragment.generateAsm(asm);
       } else {
-         asm.addAsm("  // TODO: " + statement);
+         throw new RuntimeException("Statement not supported "+statement);
       }
    }
 
@@ -79,7 +79,7 @@ public class Pass4CodeGeneration {
          StatementPhi phi = (StatementPhi) statement;
          for (StatementPhi.PreviousSymbol previousSymbol : phi.getPreviousVersions()) {
             if (previousSymbol.getBlock().equals(predecessor)) {
-               genAsmMove(asm, previousSymbol.getRValue(), phi.getLValue());
+               genAsmMove(asm, phi.getLValue(), previousSymbol.getRValue());
                break;
             }
          }
@@ -87,16 +87,9 @@ public class Pass4CodeGeneration {
       genAsmJump(asm, block.getLabel().getName());
    }
 
-   /**
-    * Generate an assembler move from an Rvalue to an LValue
-    *
-    * @param asm    The assembler sequence
-    * @param rValue The rValue
-    * @param lValue The lValue
-    */
-   private void genAsmMove(AsmSequence asm, RValue rValue, LValue lValue) {
+   private void genAsmMove(AsmSequence asm, LValue lValue, RValue rValue) {
       AsmFragment asmFragment = new AsmFragment(lValue, rValue, symbols);
-      asm.addAsm("  // " + rValue + " = " + lValue + "  // " + asmFragment.getSignature());
+      asm.addAsm("  // " + lValue + " = " + rValue + "  // " + asmFragment.getSignature());
       asmFragment.generateAsm(asm);
    }
 

src/dk/camelot64/kickc/icl/asm/zpbo1=zpby1<=coby1.asm

@@ -0,0 +1,8 @@
+lda {zpby1}
+cmp #{coby1}
+bcc !t+
+beq !t+
+!f: lda #0
+jmp !d+
+!t: lda #$ff
+!d: sta {zpbo1}

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

@@ -14,7 +14,7 @@ import java.util.List;
 /** Test my KickC Grammar */
 public class Main {
    public static void main(String[] args) throws IOException {
-      CharStream input = CharStreams.fromFileName("src/dk/camelot64/kickc/test/test.kc");
+      CharStream input = CharStreams.fromFileName("src/dk/camelot64/kickc/test/fib.kc");
       System.out.println(input.toString());
       KickCLexer lexer = new KickCLexer(input);
       KickCParser parser = new KickCParser(new CommonTokenStream(lexer));
@@ -51,6 +51,8 @@ public class Main {
             if (stepOptimized) {
                System.out.println("Succesful optimization "+optimization);
                optimized = true;
+               System.out.println("CONTROL FLOW GRAPH");
+               System.out.println(controlFlowGraph.toString());
             }
          }
       }

src/dk/camelot64/kickc/test/fib.kc

@@ -0,0 +1,10 @@
+byte num = 0;
+byte num2 = 1;
+byte i = 0;
+byte fib = 0;
+while(i<=10) {
+    fib = num + num2;
+    num = num2;
+    num2 = fib;
+    i = i + 1;
+}