*** old/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/memory/WriteNode.java	Fri Jul  7 09:31:26 2017
--- new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/memory/WriteNode.java	Fri Jul  7 09:31:26 2017

*** 22,43 ****
--- 22,46 ----
   */
  package org.graalvm.compiler.nodes.memory;
  
  import org.graalvm.compiler.core.common.LIRKind;
  import org.graalvm.compiler.core.common.type.Stamp;
+ import org.graalvm.compiler.graph.Node;
  import org.graalvm.compiler.graph.NodeClass;
+ import org.graalvm.compiler.graph.spi.Canonicalizable;
+ import org.graalvm.compiler.graph.spi.CanonicalizerTool;
  import org.graalvm.compiler.nodeinfo.NodeInfo;
  import org.graalvm.compiler.nodes.ValueNode;
  import org.graalvm.compiler.nodes.memory.address.AddressNode;
  import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
  import org.graalvm.word.LocationIdentity;
  
  /**
   * Writes a given {@linkplain #value() value} a {@linkplain FixedAccessNode memory location}.
   */
  @NodeInfo(nameTemplate = "Write#{p#location/s}")
! public class WriteNode extends AbstractWriteNode implements LIRLowerableAccess, Canonicalizable {
  
      public static final NodeClass<WriteNode> TYPE = NodeClass.create(WriteNode.class);
  
      public WriteNode(AddressNode address, LocationIdentity location, ValueNode value, BarrierType barrierType) {
          super(TYPE, address, location, value, barrierType);

*** 60,65 ****
--- 63,80 ----
  
      @Override
      public Stamp getAccessStamp() {
          return value().stamp();
      }
+ 
+     @Override
+     public Node canonical(CanonicalizerTool tool) {
+         if (tool.canonicalizeReads() && hasExactlyOneUsage() && next() instanceof WriteNode) {
+             WriteNode write = (WriteNode) next();
+             if (write.lastLocationAccess == this && write.getAddress() == getAddress() && getAccessStamp().isCompatible(write.getAccessStamp())) {
+                 write.setLastLocationAccess(getLastLocationAccess());
+                 return write;
+             }
+         }
+         return this;
+     }
  }