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.ssa;
014
015import org.jikesrvm.compilers.opt.util.SpaceEffGraphEdge;
016
017/**
018 * This class implements an edge in the value graph used in global value
019 * numbering
020 * ala Alpern, Wegman and Zadeck.  See Muchnick p.348 for a nice
021 * discussion.
022 */
023final class ValueGraphEdge extends SpaceEffGraphEdge {
024
025  ValueGraphEdge(ValueGraphVertex src, ValueGraphVertex target) {
026    super(src, target);
027  }
028
029  @Override
030  public String toString() {
031    ValueGraphVertex src = (ValueGraphVertex) fromNode();
032    ValueGraphVertex dest = (ValueGraphVertex) toNode();
033    return src.getName() + " --> " + dest.getName();
034  }
035}