001/*
002 * Copyright (c) 2011, 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.compiler.common.type.*;
026import com.oracle.graal.graph.*;
027import com.oracle.graal.nodeinfo.*;
028
029@NodeInfo
030public final class BeginNode extends AbstractBeginNode {
031
032    public static final NodeClass<BeginNode> TYPE = NodeClass.create(BeginNode.class);
033
034    public BeginNode() {
035        super(TYPE, StampFactory.forVoid());
036    }
037
038    public BeginNode(Stamp stamp) {
039        super(TYPE, stamp);
040    }
041
042    public void trySimplify() {
043        FixedNode prev = (FixedNode) this.predecessor();
044        if (prev instanceof ControlSplitNode) {
045            // This begin node is necessary.
046        } else {
047            // This begin node can be removed and all guards moved up to the preceding begin node.
048            prepareDelete();
049            graph().removeFixed(this);
050        }
051    }
052
053    public static AbstractBeginNode begin(FixedNode with) {
054        if (with instanceof AbstractBeginNode) {
055            return (AbstractBeginNode) with;
056        }
057        BeginNode begin = with.graph().add(new BeginNode());
058        begin.setNext(with);
059        return begin;
060    }
061}