1/*
2 * Copyright (c) 2012, 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 static org.graalvm.compiler.nodeinfo.InputType.Association;
26import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_0;
27import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_0;
28
29import org.graalvm.compiler.core.common.type.Stamp;
30import org.graalvm.compiler.graph.IterableNodeType;
31import org.graalvm.compiler.graph.Node.ValueNumberable;
32import org.graalvm.compiler.graph.NodeClass;
33import org.graalvm.compiler.nodeinfo.NodeInfo;
34import org.graalvm.compiler.nodes.calc.FloatingNode;
35import org.graalvm.compiler.nodes.extended.GuardingNode;
36
37/**
38 * A proxy is inserted at loop exits for any value that is created inside the loop (i.e. was not
39 * live on entry to the loop) and is (potentially) used after the loop.
40 */
41@NodeInfo(cycles = CYCLES_0, size = SIZE_0)
42public abstract class ProxyNode extends FloatingNode implements IterableNodeType, ValueNumberable {
43
44    public static final NodeClass<ProxyNode> TYPE = NodeClass.create(ProxyNode.class);
45    @Input(Association) LoopExitNode loopExit;
46
47    protected ProxyNode(NodeClass<? extends ProxyNode> c, Stamp stamp, LoopExitNode proxyPoint) {
48        super(c, stamp);
49        assert proxyPoint != null;
50        this.loopExit = proxyPoint;
51    }
52
53    public abstract ValueNode value();
54
55    public LoopExitNode proxyPoint() {
56        return loopExit;
57    }
58
59    @Override
60    public boolean verify() {
61        assert !(value() instanceof ProxyNode) || ((ProxyNode) value()).loopExit != loopExit;
62        return super.verify();
63    }
64
65    public static ValueProxyNode forValue(ValueNode value, LoopExitNode exit, StructuredGraph graph) {
66        return graph.unique(new ValueProxyNode(value, exit));
67    }
68
69    public static GuardProxyNode forGuard(GuardingNode value, LoopExitNode exit, StructuredGraph graph) {
70        return graph.unique(new GuardProxyNode(value, exit));
71    }
72}
73