001/*
002 *  This file is part of the Jikes RVM project (http://jikesrvm.org).
003 *
004 *  This file is licensed to You under the Eclipse Public License (EPL);
005 *  You may not use this file except in compliance with the License. You
006 *  may obtain a copy of the License at
007 *
008 *      http://www.opensource.org/licenses/eclipse-1.0.php
009 *
010 *  See the COPYRIGHT.txt file distributed with this work for information
011 *  regarding copyright ownership.
012 */
013package org.jikesrvm.compilers.opt;
014
015import java.util.Enumeration;
016
017import org.jikesrvm.compilers.opt.driver.CompilerPhase;
018import org.jikesrvm.compilers.opt.ir.Move;
019import org.jikesrvm.compilers.opt.ir.IR;
020import org.jikesrvm.compilers.opt.ir.IRTools;
021import org.jikesrvm.compilers.opt.ir.Instruction;
022import org.jikesrvm.compilers.opt.ir.Operator;
023import static org.jikesrvm.compilers.opt.ir.Operators.SPLIT;
024import org.jikesrvm.compilers.opt.ir.Unary;
025import org.jikesrvm.compilers.opt.ir.operand.Operand;
026import org.jikesrvm.compilers.opt.ir.operand.RegisterOperand;
027
028/**
029 * Change SPLIT operations inserting for live range splitting into Moves.
030 */
031public final class MutateSplits extends CompilerPhase {
032
033  /**
034   * Return this instance of this phase. This phase contains no
035   * per-compilation instance fields.
036   * @param ir not used
037   * @return this
038   */
039  @Override
040  public CompilerPhase newExecution(IR ir) {
041    return this;
042  }
043
044  @Override
045  public boolean shouldPerform(OptOptions options) {
046    return options.SSA_LIVE_RANGE_SPLITTING;
047  }
048
049  @Override
050  public String getName() {
051    return "Mutate Splits";
052  }
053
054  /**
055   * The main entrypoint for this pass.
056   */
057  @Override
058  public void perform(IR ir) {
059    for (Enumeration<Instruction> e = ir.forwardInstrEnumerator(); e.hasMoreElements();) {
060      Instruction s = e.nextElement();
061      if (s.operator() == SPLIT) {
062        RegisterOperand lhs = Unary.getResult(s);
063        Operator mv = IRTools.getMoveOp(lhs.getType());
064        Operand rhs = Unary.getVal(s);
065        Move.mutate(s, mv, lhs, rhs);
066      }
067    }
068  }
069}