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  */
  23 
  24 
  25 package org.graalvm.compiler.nodes.java;
  26 
  27 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_8;
  28 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_8;
  29 
  30 import org.graalvm.compiler.core.common.LIRKind;
  31 import org.graalvm.compiler.core.common.type.StampFactory;
  32 import org.graalvm.compiler.graph.NodeClass;
  33 import org.graalvm.compiler.lir.gen.LIRGeneratorTool;
  34 import org.graalvm.compiler.nodeinfo.NodeInfo;
  35 import org.graalvm.compiler.nodes.NodeView;
  36 import org.graalvm.compiler.nodes.ValueNode;
  37 import org.graalvm.compiler.nodes.memory.address.AddressNode;
  38 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
  39 import jdk.internal.vm.compiler.word.LocationIdentity;
  40 
  41 import jdk.vm.ci.meta.JavaConstant;
  42 import jdk.vm.ci.meta.JavaKind;
  43 import jdk.vm.ci.meta.Value;
  44 
  45 /**
  46  * Represents the low-level version of an atomic compare-and-swap operation.
  47  *
  48  * This version returns a boolean indicating is the CAS was successful or not.
  49  */
  50 @NodeInfo(cycles = CYCLES_8, size = SIZE_8)
  51 public final class LogicCompareAndSwapNode extends AbstractCompareAndSwapNode {
  52     public static final NodeClass<LogicCompareAndSwapNode> TYPE = NodeClass.create(LogicCompareAndSwapNode.class);
  53 
  54     public LogicCompareAndSwapNode(ValueNode address, ValueNode expectedValue, ValueNode newValue, LocationIdentity location) {
  55         this((AddressNode) address, location, expectedValue, newValue, BarrierType.NONE);
  56     }
  57 
  58     public LogicCompareAndSwapNode(AddressNode address, LocationIdentity location, ValueNode expectedValue, ValueNode newValue, BarrierType barrierType) {
  59         super(TYPE, address, location, expectedValue, newValue, barrierType, StampFactory.forInteger(JavaKind.Int, 0, 1));
  60     }
  61 
  62     @Override
  63     public void generate(NodeLIRBuilderTool gen) {
  64         assert getNewValue().stamp(NodeView.DEFAULT).isCompatible(getExpectedValue().stamp(NodeView.DEFAULT));
  65         assert !this.canDeoptimize();
  66         LIRGeneratorTool tool = gen.getLIRGeneratorTool();
  67 
  68         LIRKind resultKind = tool.getLIRKind(stamp(NodeView.DEFAULT));
  69         Value trueResult = tool.emitConstant(resultKind, JavaConstant.TRUE);
  70         Value falseResult = tool.emitConstant(resultKind, JavaConstant.FALSE);
  71         Value result = tool.emitLogicCompareAndSwap(tool.getLIRKind(getAccessStamp()), gen.operand(getAddress()), gen.operand(getExpectedValue()), gen.operand(getNewValue()), trueResult, falseResult);
  72 
  73         gen.setResult(this, result);
  74     }
  75 }