1 /*
   2  * Copyright (c) 2011, 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.memory;
  24 
  25 import org.graalvm.compiler.core.common.LIRKind;
  26 import org.graalvm.compiler.core.common.type.Stamp;
  27 import org.graalvm.compiler.graph.Node;
  28 import org.graalvm.compiler.graph.NodeClass;
  29 import org.graalvm.compiler.graph.spi.Canonicalizable;
  30 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
  31 import org.graalvm.compiler.nodeinfo.NodeInfo;
  32 import org.graalvm.compiler.nodes.ValueNode;
  33 import org.graalvm.compiler.nodes.memory.address.AddressNode;
  34 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
  35 import org.graalvm.word.LocationIdentity;
  36 
  37 /**
  38  * Writes a given {@linkplain #value() value} a {@linkplain FixedAccessNode memory location}.
  39  */
  40 @NodeInfo(nameTemplate = "Write#{p#location/s}")
  41 public class WriteNode extends AbstractWriteNode implements LIRLowerableAccess, Canonicalizable {
  42 
  43     public static final NodeClass<WriteNode> TYPE = NodeClass.create(WriteNode.class);
  44 
  45     public WriteNode(AddressNode address, LocationIdentity location, ValueNode value, BarrierType barrierType) {
  46         super(TYPE, address, location, value, barrierType);
  47     }
  48 
  49     protected WriteNode(NodeClass<? extends WriteNode> c, AddressNode address, LocationIdentity location, ValueNode value, BarrierType barrierType) {
  50         super(c, address, location, value, barrierType);
  51     }
  52 
  53     @Override
  54     public void generate(NodeLIRBuilderTool gen) {
  55         LIRKind writeKind = gen.getLIRGeneratorTool().getLIRKind(value().stamp());
  56         gen.getLIRGeneratorTool().getArithmetic().emitStore(writeKind, gen.operand(address), gen.operand(value()), gen.state(this));
  57     }
  58 
  59     @Override
  60     public boolean canNullCheck() {
  61         return true;
  62     }
  63 
  64     @Override
  65     public Stamp getAccessStamp() {
  66         return value().stamp();
  67     }
  68 
  69     @Override
  70     public Node canonical(CanonicalizerTool tool) {
  71         if (tool.canonicalizeReads() && hasExactlyOneUsage() && next() instanceof WriteNode) {
  72             WriteNode write = (WriteNode) next();
  73             if (write.lastLocationAccess == this && write.getAddress() == getAddress() && getAccessStamp().isCompatible(write.getAccessStamp())) {
  74                 write.setLastLocationAccess(getLastLocationAccess());
  75                 return write;
  76             }
  77         }
  78         return this;
  79     }
  80 }