Added ASM optimization removing jumps / branches to next instruction.

src/dk/camelot64/kickc/asm/AsmFragment.java

@@ -32,7 +32,7 @@ public class AsmFragment {
     */
    private String signature;
 
-   public AsmFragment(StatementConditionalJump conditionalJump, SymbolTable symbols, ControlFlowGraph graph, ControlFlowBlock block) {
+   public AsmFragment(StatementConditionalJump conditionalJump, ControlFlowBlock block, SymbolTable symbols, ControlFlowGraph graph) {
       this.bindings = new HashMap<>();
       this.symbols = symbols;
       StringBuilder signature = new StringBuilder();

src/dk/camelot64/kickc/asm/AsmInstruction.java

@@ -15,6 +15,14 @@ public class AsmInstruction implements AsmLine {
       this.invocationCountEstimate = invocationCountEstimate;
    }
 
+   public String getParameter() {
+      return parameter;
+   }
+
+   public AsmInstructionType getType() {
+      return type;
+   }
+
    @Override
    public int getLineBytes() {
       return type.getBytes();

src/dk/camelot64/kickc/asm/AsmInstructionType.java

@@ -11,6 +11,8 @@ public class AsmInstructionType {
 
    private double cycles;
 
+   private boolean jump;
+
    public AsmInstructionType(int opcode, String mnemnonic, AsmAddressingMode addressingMode, double cycles) {
       this.opcode = opcode;
       this.mnemnonic = mnemnonic;
@@ -38,4 +40,16 @@ public class AsmInstructionType {
       return addressingMode.getAsm(mnemnonic, parameter);
    }
 
+   /**
+    * Tells if the instruction is a jump or a branch (and the parameter is therefore a label or destination address)
+    * @return true if the instruction is a jump/branch
+    */
+   public boolean isJump() {
+      return jump;
+   }
+
+   void setJump(boolean jump) {
+      this.jump = jump;
+   }
+
 }

src/dk/camelot64/kickc/asm/AsmInstuctionSet.java

@@ -322,7 +322,20 @@ public class AsmInstuctionSet {
       add(0xfd, "SBC", abx, 4.5);
       add(0xfe, "INC", abx, 7.0);
       add(0xff, "ISC", abx, 7.0);
-
+      for (AsmInstructionType instruction : instructions) {
+         switch(instruction.getMnemnonic()) {
+            case "jmp":
+            case "beq":
+            case "bne":
+            case "bcc":
+            case "bcs":
+            case "bvc":
+            case "bvs":
+            case "bmi":
+            case "bpl":
+               instruction.setJump(true);
+         }
+      }
    }
 
    public AsmInstructionType getType(String mnemonic, AsmAddressingMode addressingMode) {

src/dk/camelot64/kickc/asm/AsmLabel.java

@@ -9,6 +9,10 @@ public class AsmLabel implements AsmLine {
       this.label = label;
    }
 
+   public String getLabel() {
+      return label;
+   }
+
    @Override
    public int getLineBytes() {
       return 0;

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

@@ -50,7 +50,7 @@ public class Pass4CodeGeneration {
          asm.addComment(statement + "  //  " + asmFragment.getSignature());
          asmFragment.generate(asm);
       } else if (statement instanceof StatementConditionalJump) {
-         AsmFragment asmFragment = new AsmFragment((StatementConditionalJump) statement, symbols, graph, block);
+         AsmFragment asmFragment = new AsmFragment((StatementConditionalJump) statement, block, symbols, graph);
          asm.addComment(statement + "  //  " + asmFragment.getSignature());
          asmFragment.generate(asm);
       } else {

src/dk/camelot64/kickc/icl/Pass5NextJumpElimination.java

@@ -0,0 +1,50 @@
+package dk.camelot64.kickc.icl;
+
+import dk.camelot64.kickc.asm.AsmInstruction;
+import dk.camelot64.kickc.asm.AsmLabel;
+import dk.camelot64.kickc.asm.AsmLine;
+import dk.camelot64.kickc.asm.AsmProgram;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+/** Optimize assembler code by removing jumps to labels immediately following the jump */
+public class Pass5NextJumpElimination {
+
+   private AsmProgram program;
+
+   public Pass5NextJumpElimination(AsmProgram program) {
+      this.program = program;
+   }
+
+   public boolean optimize() {
+      List<AsmLine> remove = new ArrayList<>();
+      AsmInstruction candidate = null;
+      for (AsmLine line : program.getLines()) {
+         if(candidate!=null) {
+            if(line instanceof AsmLabel) {
+               if(((AsmLabel) line).getLabel().equals(candidate.getParameter())) {
+                  remove.add(candidate);
+                  candidate = null;
+               }
+            }
+         }
+         if(line instanceof AsmInstruction) {
+            candidate = null;
+            AsmInstruction instruction = (AsmInstruction) line;
+            if(instruction.getType().isJump()) {
+               candidate = instruction;
+            }
+         }
+      }
+      for (Iterator<AsmLine> iterator = program.getLines().iterator(); iterator.hasNext(); ) {
+         AsmLine line = iterator.next();
+         if (remove.contains(line)) {
+            System.out.println("Removing jump to next instruction "+line.getAsm());
+            iterator.remove();
+         }
+      }
+      return remove.size()>0;
+   }
+}

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

@@ -68,8 +68,10 @@ public class Main {
       pass3RegisterAllocation.allocate();
 
       Pass4CodeGeneration pass4CodeGeneration = new Pass4CodeGeneration(controlFlowGraph, symbolTable);
-
       AsmProgram asmProgram = pass4CodeGeneration.generate();
+      Pass5NextJumpElimination pass5NextJumpElimination = new Pass5NextJumpElimination(asmProgram);
+      pass5NextJumpElimination.optimize();
+
 
       System.out.println("SYMBOLS");
       System.out.println(symbolTable.toString());