1/*
2 * Copyright (c) 2012, 2016, 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.java;
24
25import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_8;
26import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_8;
27
28import org.graalvm.compiler.graph.NodeClass;
29import org.graalvm.compiler.lir.gen.LIRGeneratorTool;
30import org.graalvm.compiler.nodeinfo.NodeInfo;
31import org.graalvm.compiler.nodes.ValueNode;
32import org.graalvm.compiler.nodes.memory.address.AddressNode;
33import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
34import org.graalvm.word.LocationIdentity;
35
36/**
37 * A special purpose store node that differs from {@link LogicCompareAndSwapNode} in that it returns
38 * either the expected value or the compared against value instead of a boolean.
39 */
40@NodeInfo(cycles = CYCLES_8, size = SIZE_8)
41public final class ValueCompareAndSwapNode extends AbstractCompareAndSwapNode {
42    public static final NodeClass<ValueCompareAndSwapNode> TYPE = NodeClass.create(ValueCompareAndSwapNode.class);
43
44    public ValueCompareAndSwapNode(ValueNode address, ValueNode expectedValue, ValueNode newValue, LocationIdentity location) {
45        this((AddressNode) address, expectedValue, newValue, location, BarrierType.NONE);
46    }
47
48    public ValueCompareAndSwapNode(AddressNode address, ValueNode expectedValue, ValueNode newValue, LocationIdentity location, BarrierType barrierType) {
49        super(TYPE, address, location, expectedValue, newValue, barrierType, expectedValue.stamp().meet(newValue.stamp()).unrestricted());
50    }
51
52    @Override
53    public void generate(NodeLIRBuilderTool gen) {
54        assert getNewValue().stamp().isCompatible(getExpectedValue().stamp());
55        LIRGeneratorTool tool = gen.getLIRGeneratorTool();
56        assert !this.canDeoptimize();
57        gen.setResult(this, tool.emitValueCompareAndSwap(gen.operand(getAddress()), gen.operand(getExpectedValue()), gen.operand(getNewValue())));
58    }
59}
60