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.compiler.common.type.*;
026import com.oracle.graal.graph.*;
027import com.oracle.graal.nodeinfo.*;
028import com.oracle.graal.nodes.spi.*;
029import com.oracle.graal.nodes.type.*;
030import com.oracle.graal.nodes.util.*;
031
032/**
033 * Value {@link PhiNode}s merge data flow values at control flow merges.
034 */
035@NodeInfo(nameTemplate = "Phi({i#values})")
036public class ValuePhiNode extends PhiNode implements ArrayLengthProvider {
037
038    public static final NodeClass<ValuePhiNode> TYPE = NodeClass.create(ValuePhiNode.class);
039    @Input protected NodeInputList<ValueNode> values;
040
041    public ValuePhiNode(Stamp stamp, AbstractMergeNode merge) {
042        this(TYPE, stamp, merge);
043    }
044
045    protected ValuePhiNode(NodeClass<? extends ValuePhiNode> c, Stamp stamp, AbstractMergeNode merge) {
046        super(c, stamp, merge);
047        assert stamp != StampFactory.forVoid();
048        values = new NodeInputList<>(this);
049    }
050
051    public ValuePhiNode(Stamp stamp, AbstractMergeNode merge, ValueNode[] values) {
052        super(TYPE, stamp, merge);
053        assert stamp != StampFactory.forVoid();
054        this.values = new NodeInputList<>(this, values);
055    }
056
057    @Override
058    public NodeInputList<ValueNode> values() {
059        return values;
060    }
061
062    @Override
063    public boolean inferStamp() {
064        Stamp valuesStamp = StampTool.meet(values());
065        if (stamp.isCompatible(valuesStamp)) {
066            valuesStamp = stamp.join(valuesStamp);
067        }
068        return updateStamp(valuesStamp);
069    }
070
071    public ValueNode length() {
072        if (merge() instanceof LoopBeginNode) {
073            return null;
074        }
075        ValueNode length = null;
076        for (ValueNode input : values()) {
077            ValueNode l = GraphUtil.arrayLength(input);
078            if (l == null) {
079                return null;
080            }
081            if (length == null) {
082                length = l;
083            } else if (length != l) {
084                return null;
085            }
086        }
087        return length;
088    }
089}