/*

 * Copyright (c) 2009, 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package org.graalvm.compiler.nodes;

import org.graalvm.compiler.graph.NodeClass;

import org.graalvm.compiler.nodeinfo.NodeInfo;

/**

 * Denotes the merging of multiple control-flow paths.

 */

@NodeInfo

public final class MergeNode extends AbstractMergeNode {

    public static final NodeClass<MergeNode> TYPE = NodeClass.create(MergeNode.class);

    public MergeNode() {

        super(TYPE);

    }

    public static void removeMergeIfDegenerated(MergeNode node) {

        if (node.forwardEndCount() == 1 && node.hasNoUsages()) {

            FixedNode currentNext = node.next();

            node.setNext(null);

            EndNode forwardEnd = node.forwardEndAt(0);

            forwardEnd.replaceAtPredecessor(currentNext);

            node.markDeleted();

            forwardEnd.markDeleted();

        }

    }

    @Override

    public boolean verify() {

        assertTrue(this.forwardEndCount() > 1, "Must merge more than one end.");

        return true;

    }

}