1/*
2 * Copyright (c) 2009, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23package org.graalvm.compiler.nodes;
24
25import org.graalvm.compiler.core.common.type.Stamp;
26import org.graalvm.compiler.core.common.type.StampFactory;
27import org.graalvm.compiler.graph.NodeClass;
28import org.graalvm.compiler.graph.NodeInputList;
29import org.graalvm.compiler.nodeinfo.NodeInfo;
30import org.graalvm.compiler.nodes.spi.ArrayLengthProvider;
31import org.graalvm.compiler.nodes.type.StampTool;
32import org.graalvm.compiler.nodes.util.GraphUtil;
33import org.graalvm.util.CollectionsUtil;
34
35/**
36 * Value {@link PhiNode}s merge data flow values at control flow merges.
37 */
38@NodeInfo(nameTemplate = "Phi({i#values})")
39public class ValuePhiNode extends PhiNode implements ArrayLengthProvider {
40
41    public static final NodeClass<ValuePhiNode> TYPE = NodeClass.create(ValuePhiNode.class);
42    @Input protected NodeInputList<ValueNode> values;
43
44    public ValuePhiNode(Stamp stamp, AbstractMergeNode merge) {
45        this(TYPE, stamp, merge);
46    }
47
48    protected ValuePhiNode(NodeClass<? extends ValuePhiNode> c, Stamp stamp, AbstractMergeNode merge) {
49        super(c, stamp, merge);
50        assert stamp != StampFactory.forVoid();
51        values = new NodeInputList<>(this);
52    }
53
54    public ValuePhiNode(Stamp stamp, AbstractMergeNode merge, ValueNode[] values) {
55        super(TYPE, stamp, merge);
56        assert stamp != StampFactory.forVoid();
57        this.values = new NodeInputList<>(this, values);
58    }
59
60    @Override
61    public NodeInputList<ValueNode> values() {
62        return values;
63    }
64
65    @Override
66    public boolean inferStamp() {
67        /*
68         * Meet all the values feeding this Phi but don't use the stamp of this Phi since that's
69         * what's being computed.
70         */
71        Stamp valuesStamp = StampTool.meetOrNull(values(), this);
72        if (valuesStamp == null) {
73            valuesStamp = stamp;
74        } else if (stamp.isCompatible(valuesStamp)) {
75            valuesStamp = stamp.join(valuesStamp);
76        }
77        return updateStamp(valuesStamp);
78    }
79
80    @Override
81    public ValueNode length() {
82        if (merge() instanceof LoopBeginNode) {
83            return null;
84        }
85        ValueNode length = null;
86        for (ValueNode input : values()) {
87            ValueNode l = GraphUtil.arrayLength(input);
88            if (l == null) {
89                return null;
90            }
91            if (length == null) {
92                length = l;
93            } else if (length != l) {
94                return null;
95            }
96        }
97        return length;
98    }
99
100    @Override
101    public boolean verify() {
102        Stamp s = null;
103        for (ValueNode input : values()) {
104            assert input != null;
105            if (s == null) {
106                s = input.stamp();
107            } else {
108                if (!s.isCompatible(input.stamp())) {
109                    fail("Phi Input Stamps are not compatible. Phi:%s inputs:%s", this,
110                                    CollectionsUtil.mapAndJoin(values(), x -> x.toString() + ":" + x.stamp(), ", "));
111                }
112            }
113        }
114        return super.verify();
115    }
116}
117