1/*
2 * Copyright (c) 2012, 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.graph.Node;
26import org.graalvm.compiler.graph.NodeClass;
27import org.graalvm.compiler.graph.spi.Canonicalizable;
28import org.graalvm.compiler.graph.spi.CanonicalizerTool;
29import org.graalvm.compiler.nodeinfo.NodeInfo;
30import org.graalvm.compiler.nodes.extended.GuardingNode;
31import org.graalvm.compiler.nodes.spi.ValueProxy;
32import org.graalvm.compiler.nodes.spi.Virtualizable;
33import org.graalvm.compiler.nodes.spi.VirtualizerTool;
34import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;
35
36@NodeInfo(nameTemplate = "Proxy({i#value})")
37public final class ValueProxyNode extends ProxyNode implements Canonicalizable, Virtualizable, ValueProxy {
38
39    public static final NodeClass<ValueProxyNode> TYPE = NodeClass.create(ValueProxyNode.class);
40    @Input ValueNode value;
41    private final boolean loopPhiProxy;
42
43    public ValueProxyNode(ValueNode value, LoopExitNode loopExit) {
44        super(TYPE, value.stamp(), loopExit);
45        this.value = value;
46        loopPhiProxy = loopExit.loopBegin().isPhiAtMerge(value);
47    }
48
49    @Override
50    public ValueNode value() {
51        return value;
52    }
53
54    @Override
55    public boolean inferStamp() {
56        return updateStamp(value.stamp());
57    }
58
59    @Override
60    public Node canonical(CanonicalizerTool tool) {
61        ValueNode curValue = value;
62        if (curValue.isConstant()) {
63            return curValue;
64        }
65        if (loopPhiProxy && !loopExit.loopBegin().isPhiAtMerge(curValue)) {
66            return curValue;
67        }
68        return this;
69    }
70
71    @Override
72    public void virtualize(VirtualizerTool tool) {
73        ValueNode alias = tool.getAlias(value);
74        if (alias instanceof VirtualObjectNode) {
75            tool.replaceWithVirtual((VirtualObjectNode) alias);
76        }
77    }
78
79    @Override
80    public ValueNode getOriginalNode() {
81        return value();
82    }
83
84    @Override
85    public GuardingNode getGuard() {
86        return this.proxyPoint();
87    }
88}
89