1/*
2 * Copyright (c) 2013, 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.core.common.LIRKind;
29import org.graalvm.compiler.core.common.type.StampFactory;
30import org.graalvm.compiler.graph.NodeClass;
31import org.graalvm.compiler.lir.gen.LIRGeneratorTool;
32import org.graalvm.compiler.nodeinfo.NodeInfo;
33import org.graalvm.compiler.nodes.ValueNode;
34import org.graalvm.compiler.nodes.memory.address.AddressNode;
35import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
36import org.graalvm.word.LocationIdentity;
37
38import jdk.vm.ci.meta.JavaConstant;
39import jdk.vm.ci.meta.JavaKind;
40import jdk.vm.ci.meta.Value;
41
42/**
43 * Represents the low-level version of an atomic compare-and-swap operation.
44 *
45 * This version returns a boolean indicating is the CAS was successful or not.
46 */
47@NodeInfo(cycles = CYCLES_8, size = SIZE_8)
48public final class LogicCompareAndSwapNode extends AbstractCompareAndSwapNode {
49    public static final NodeClass<LogicCompareAndSwapNode> TYPE = NodeClass.create(LogicCompareAndSwapNode.class);
50
51    public LogicCompareAndSwapNode(ValueNode address, ValueNode expectedValue, ValueNode newValue, LocationIdentity location) {
52        this((AddressNode) address, location, expectedValue, newValue, BarrierType.NONE);
53    }
54
55    public LogicCompareAndSwapNode(AddressNode address, LocationIdentity location, ValueNode expectedValue, ValueNode newValue, BarrierType barrierType) {
56        super(TYPE, address, location, expectedValue, newValue, barrierType, StampFactory.forKind(JavaKind.Boolean.getStackKind()));
57    }
58
59    @Override
60    public void generate(NodeLIRBuilderTool gen) {
61        assert getNewValue().stamp().isCompatible(getExpectedValue().stamp());
62        assert !this.canDeoptimize();
63        LIRGeneratorTool tool = gen.getLIRGeneratorTool();
64
65        LIRKind resultKind = tool.getLIRKind(stamp());
66        Value trueResult = tool.emitConstant(resultKind, JavaConstant.TRUE);
67        Value falseResult = tool.emitConstant(resultKind, JavaConstant.FALSE);
68        Value result = tool.emitLogicCompareAndSwap(gen.operand(getAddress()), gen.operand(getExpectedValue()), gen.operand(getNewValue()), trueResult, falseResult);
69
70        gen.setResult(this, result);
71    }
72}
73