001/*
002 * Copyright (c) 2012, 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/**
030 * Base class for {@link AbstractBeginNode}s that are associated with a frame state.
031 *
032 * TODO (dnsimon) this not needed until {@link AbstractBeginNode} no longer implements
033 * {@link StateSplit} which is not possible until loop peeling works without requiring begin nodes
034 * to have frames states.
035 */
036@NodeInfo
037public abstract class BeginStateSplitNode extends AbstractBeginNode implements StateSplit {
038
039    public static final NodeClass<BeginStateSplitNode> TYPE = NodeClass.create(BeginStateSplitNode.class);
040    @OptionalInput(InputType.State) protected FrameState stateAfter;
041
042    protected BeginStateSplitNode(NodeClass<? extends BeginStateSplitNode> c) {
043        super(c);
044    }
045
046    protected BeginStateSplitNode(NodeClass<? extends BeginStateSplitNode> c, Stamp stamp) {
047        super(c, stamp);
048    }
049
050    public FrameState stateAfter() {
051        return stateAfter;
052    }
053
054    public void setStateAfter(FrameState x) {
055        assert x == null || x.isAlive() : "frame state must be in a graph";
056        updateUsages(stateAfter, x);
057        stateAfter = x;
058    }
059
060    /**
061     * A begin node has no side effect.
062     */
063    @Override
064    public boolean hasSideEffect() {
065        return false;
066    }
067}