001/*
002 * Copyright (c) 2009, 2015, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package com.oracle.graal.nodes;
024
025import com.oracle.graal.graph.*;
026import com.oracle.graal.nodeinfo.*;
027
028/**
029 * Denotes the merging of multiple control-flow paths.
030 */
031@NodeInfo
032public final class MergeNode extends AbstractMergeNode {
033
034    public static final NodeClass<MergeNode> TYPE = NodeClass.create(MergeNode.class);
035
036    public MergeNode() {
037        super(TYPE);
038    }
039
040    public static void removeMergeIfDegenerated(MergeNode node) {
041        if (node.forwardEndCount() == 1 && node.hasNoUsages()) {
042            FixedNode currentNext = node.next();
043            node.setNext(null);
044            EndNode forwardEnd = node.forwardEndAt(0);
045            forwardEnd.replaceAtPredecessor(currentNext);
046            node.markDeleted();
047            forwardEnd.markDeleted();
048        }
049    }
050
051    @Override
052    public boolean verify() {
053        assertTrue(this.forwardEndCount() > 1, "Must merge more than one end.");
054        return true;
055    }
056}