1 /*
   2  * Copyright (c) 2014, 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 package org.graalvm.compiler.nodes.java;
  24 
  25 import static org.graalvm.compiler.nodeinfo.InputType.Memory;
  26 import static org.graalvm.compiler.nodeinfo.InputType.State;
  27 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_8;
  28 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_2;
  29 
  30 import org.graalvm.compiler.core.common.LocationIdentity;
  31 import org.graalvm.compiler.graph.NodeClass;
  32 import org.graalvm.compiler.nodeinfo.NodeInfo;
  33 import org.graalvm.compiler.nodes.FrameState;
  34 import org.graalvm.compiler.nodes.StateSplit;
  35 import org.graalvm.compiler.nodes.ValueNode;
  36 import org.graalvm.compiler.nodes.memory.FixedAccessNode;
  37 import org.graalvm.compiler.nodes.memory.MemoryCheckpoint;
  38 import org.graalvm.compiler.nodes.memory.address.AddressNode;
  39 import org.graalvm.compiler.nodes.spi.LIRLowerable;
  40 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
  41 
  42 import jdk.vm.ci.meta.Value;
  43 import sun.misc.Unsafe;
  44 
  45 /**
  46  * Represents the lowered version of an atomic read-and-write operation like
  47  * {@link Unsafe#getAndSetInt(Object, long, int)} .
  48  */
  49 @NodeInfo(allowedUsageTypes = {Memory}, cycles = CYCLES_8, size = SIZE_2)
  50 public final class LoweredAtomicReadAndWriteNode extends FixedAccessNode implements StateSplit, LIRLowerable, MemoryCheckpoint.Single {
  51 
  52     public static final NodeClass<LoweredAtomicReadAndWriteNode> TYPE = NodeClass.create(LoweredAtomicReadAndWriteNode.class);
  53     @Input ValueNode newValue;
  54     @OptionalInput(State) FrameState stateAfter;
  55 
  56     public LoweredAtomicReadAndWriteNode(AddressNode address, LocationIdentity location, ValueNode newValue, BarrierType barrierType) {
  57         super(TYPE, address, location, newValue.stamp().unrestricted(), barrierType);
  58         this.newValue = newValue;
  59     }
  60 
  61     @Override
  62     public FrameState stateAfter() {
  63         return stateAfter;
  64     }
  65 
  66     @Override
  67     public void setStateAfter(FrameState x) {
  68         assert x == null || x.isAlive() : "frame state must be in a graph";
  69         updateUsages(stateAfter, x);
  70         stateAfter = x;
  71     }
  72 
  73     @Override
  74     public boolean hasSideEffect() {
  75         return true;
  76     }
  77 
  78     @Override
  79     public void generate(NodeLIRBuilderTool gen) {
  80         Value result = gen.getLIRGeneratorTool().emitAtomicReadAndWrite(gen.operand(getAddress()), gen.operand(getNewValue()));
  81         gen.setResult(this, result);
  82     }
  83 
  84     @Override
  85     public boolean canNullCheck() {
  86         return false;
  87     }
  88 
  89     public ValueNode getNewValue() {
  90         return newValue;
  91     }
  92 }