gt:         sum += o.x;
context: /*
   * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  package com.oracle.graal.compiler.test.ea;
  
  import java.util.List;
  
  import org.junit.Test;
  
  import com.oracle.graal.compiler.test.GraalCompilerTest;
  import com.oracle.graal.nodes.ProxyNode;
  import com.oracle.graal.nodes.ReturnNode;
  import com.oracle.graal.nodes.StructuredGraph;
  import com.oracle.graal.nodes.StructuredGraph.AllowAssumptions;
  import com.oracle.graal.nodes.ValueNode;
  import com.oracle.graal.nodes.ValuePhiNode;
  import com.oracle.graal.nodes.java.LoadFieldNode;
  import com.oracle.graal.nodes.java.StoreFieldNode;
  import com.oracle.graal.phases.common.CanonicalizerPhase;
  import com.oracle.graal.phases.common.inlining.InliningPhase;
  import com.oracle.graal.phases.tiers.HighTierContext;
  import com.oracle.graal.virtual.phases.ea.EarlyReadEliminationPhase;
  
  public class EarlyReadEliminationTest extends GraalCompilerTest {
  
      protected StructuredGraph graph;
  
      public static Object staticField;
  
      public static class TestObject {
  
          public int x;
          public int y;
  
          public TestObject(int x, int y) {
              this.x = x;
              this.y = y;
          }
      }
  
      public static class TestObject2 {
  
          public Object x;
          public Object y;
  
          public TestObject2(Object x, Object y) {
              this.x = x;
              this.y = y;
          }
      }
  
      public static class TestObject3 extends TestObject {
  
          public int z;
  
          public TestObject3(int x, int y, int z) {
              super(x, y);
              this.z = z;
          }
      }
  
      @SuppressWarnings("all")
      public static int testSimpleSnippet(TestObject a) {
          a.x = 2;
          staticField = a;
          return a.x;
      }
  
      @Test
      public void testSimple() {
          ValueNode result = getReturn("testSimpleSnippet").result();
          assertTrue(graph.getNodes().filter(LoadFieldNode.class).isEmpty());
          assertTrue(result.isConstant());
          assertDeepEquals(2, result.asJavaConstant().asInt());
      }
  
      @SuppressWarnings("all")
      public static int testSimpleConflictSnippet(TestObject a, TestObject b) {
          a.x = 2;
          b.x = 3;
          staticField = a;
          return a.x;
      }
  
      @Test
      public void testSimpleConflict() {
          ValueNode result = getReturn("testSimpleConflictSnippet").result();
          assertFalse(result.isConstant());
          assertTrue(result instanceof LoadFieldNode);
      }
  
      @SuppressWarnings("all")
      public static int testParamSnippet(TestObject a, int b) {
          a.x = b;
          return a.x;
      }
  
      @Test
      public void testParam() {
          ValueNode result = getReturn("testParamSnippet").result();
          assertTrue(graph.getNodes().filter(LoadFieldNode.class).isEmpty());
          assertDeepEquals(graph.getParameter(1), result);
      }
  
      @SuppressWarnings("all")
      public static int testMaterializedSnippet(int a) {
          TestObject obj = new TestObject(a, 0);
          staticField = obj;
          return obj.x;
      }
  
      @Test
      public void testMaterialized() {
          ValueNode result = getReturn("testMaterializedSnippet").result();
          assertTrue(graph.getNodes().filter(LoadFieldNode.class).isEmpty());
          assertDeepEquals(graph.getParameter(0), result);
      }
  
      @SuppressWarnings("all")
      public static int testSimpleLoopSnippet(TestObject obj, int a, int b) {
          obj.x = a;
          for (int i = 0; i < 10; i++) {
              staticField = obj;
          }
          return obj.x;
      }
  
      @Test
      public void testSimpleLoop() {
          ValueNode result = getReturn("testSimpleLoopSnippet").result();
          assertTrue(graph.getNodes().filter(LoadFieldNode.class).isEmpty());
          assertDeepEquals(graph.getParameter(1), result);
      }
  
      @SuppressWarnings("all")
      public static int testBadLoopSnippet(TestObject obj, TestObject obj2, int a, int b) {
          obj.x = a;
          for (int i = 0; i < 10; i++) {
              staticField = obj;
              obj2.x = 10;
              obj.x = 0;
          }
          return obj.x;
      }
  
      @Test
      public void testBadLoop() {
          ValueNode result = getReturn("testBadLoopSnippet").result();
          assertDeepEquals(0, graph.getNodes().filter(LoadFieldNode.class).count());
          assertTrue(result instanceof ProxyNode);
          assertTrue(((ProxyNode) result).value() instanceof ValuePhiNode);
      }
  
      @SuppressWarnings("all")
      public static int testBadLoop2Snippet(TestObject obj, TestObject obj2, int a, int b) {
          obj.x = a;
          for (int i = 0; i < 10; i++) {
              obj.x = 0;
              obj2.x = 10;
          }
          return obj.x;
      }
  
      @Test
      public void testBadLoop2() {
          ValueNode result = getReturn("testBadLoop2Snippet").result();
          assertDeepEquals(1, graph.getNodes().filter(LoadFieldNode.class).count());
          assertTrue(result instanceof LoadFieldNode);
      }
  
      @SuppressWarnings("all")
      public static int testPhiSnippet(TestObject a, int b) {
          if (b < 0) {
              a.x = 1;
          } else {
              a.x = 2;
          }
          return a.x;
      }
  
      @Test
      public void testPhi() {
          processMethod("testPhiSnippet");
          assertTrue(graph.getNodes().filter(LoadFieldNode.class).isEmpty());
          List<ReturnNode> returnNodes = graph.getNodes(ReturnNode.TYPE).snapshot();
          assertDeepEquals(2, returnNodes.size());
          assertTrue(returnNodes.get(0).predecessor() instanceof StoreFieldNode);
          assertTrue(returnNodes.get(1).predecessor() instanceof StoreFieldNode);
          assertTrue(returnNodes.get(0).result().isConstant());
          assertTrue(returnNodes.get(1).result().isConstant());
      }
  
      @SuppressWarnings("all")
      public static void testSimpleStoreSnippet(TestObject a, int b) {
          a.x = b;
          a.x = b;
      }
  
      @Test
      public void testSimpleStore() {
          processMethod("testSimpleStoreSnippet");
          assertDeepEquals(1, graph.getNodes().filter(StoreFieldNode.class).count());
      }
  
      public static int testValueProxySnippet(boolean b, TestObject o) {
          int sum = 0;
          if (b) {
              sum += o.x;
          } else {
              TestObject3 p = (TestObject3) o;
              sum += p.x;
          }
  