gt:                 if (read.getBarrierType() != BarrierType.NONE) {
context: /*
   * Copyright (c) 2013, 2015, 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 org.graalvm.compiler.hotspot.test;
  
  import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.config;
  import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.referentOffset;
  
  import java.lang.ref.WeakReference;
  
  import org.junit.Assert;
  import org.junit.Test;
  
  import org.graalvm.compiler.debug.Debug;
  import org.graalvm.compiler.debug.Debug.Scope;
  import org.graalvm.compiler.hotspot.GraalHotSpotVMConfig;
  import org.graalvm.compiler.hotspot.nodes.G1PostWriteBarrier;
  import org.graalvm.compiler.hotspot.nodes.G1PreWriteBarrier;
  import org.graalvm.compiler.hotspot.nodes.G1ReferentFieldReadBarrier;
  import org.graalvm.compiler.hotspot.nodes.SerialWriteBarrier;
  import org.graalvm.compiler.hotspot.phases.WriteBarrierAdditionPhase;
  import org.graalvm.compiler.nodes.StructuredGraph;
  import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;
  import org.graalvm.compiler.nodes.memory.HeapAccess.BarrierType;
  import org.graalvm.compiler.nodes.memory.ReadNode;
  import org.graalvm.compiler.nodes.memory.WriteNode;
  import org.graalvm.compiler.nodes.memory.address.OffsetAddressNode;
  import org.graalvm.compiler.nodes.spi.LoweringTool;
  import org.graalvm.compiler.phases.OptimisticOptimizations;
  import org.graalvm.compiler.phases.common.CanonicalizerPhase;
  import org.graalvm.compiler.phases.common.GuardLoweringPhase;
  import org.graalvm.compiler.phases.common.LoweringPhase;
  import org.graalvm.compiler.phases.common.inlining.InliningPhase;
  import org.graalvm.compiler.phases.common.inlining.policy.InlineEverythingPolicy;
  import org.graalvm.compiler.phases.tiers.HighTierContext;
  import org.graalvm.compiler.phases.tiers.MidTierContext;
  
  import jdk.vm.ci.hotspot.HotSpotInstalledCode;
  import jdk.vm.ci.meta.JavaConstant;
  import jdk.vm.ci.meta.ResolvedJavaMethod;
  import sun.misc.Unsafe;
  
  /**
   * The following unit tests assert the presence of write barriers for both Serial and G1 GCs.
   * Normally, the tests check for compile time inserted barriers. However, there are the cases of
   * unsafe loads of the java.lang.ref.Reference.referent field where runtime checks have to be
   * performed also. For those cases, the unit tests check the presence of the compile-time inserted
   * barriers. Concerning the runtime checks, the results of variable inputs (object types and
   * offsets) passed as input parameters can be checked against printed output from the G1 write
   * barrier snippets. The runtime checks have been validated offline.
   */
  public class WriteBarrierAdditionTest extends HotSpotGraalCompilerTest {
  
      private final GraalHotSpotVMConfig config = runtime().getVMConfig();
      private static final long referentOffset = referentOffset();
  
      public static class Container {
  
          public Container a;
          public Container b;
      }
  
      /**
       * Expected 2 barriers for the Serial GC and 4 for G1 (2 pre + 2 post).
       */
      @Test
      public void test1() throws Exception {
          testHelper("test1Snippet", (config.useG1GC) ? 4 : 2);
      }
  
      public static void test1Snippet() {
          Container main = new Container();
          Container temp1 = new Container();
          Container temp2 = new Container();
          main.a = temp1;
          main.b = temp2;
      }
  
      /**
       * Expected 4 barriers for the Serial GC and 8 for G1 (4 pre + 4 post).
       */
      @Test
      public void test2() throws Exception {
          testHelper("test2Snippet", config.useG1GC ? 8 : 4);
      }
  
      public static void test2Snippet(boolean test) {
          Container main = new Container();
          Container temp1 = new Container();
          Container temp2 = new Container();
          for (int i = 0; i < 10; i++) {
              if (test) {
                  main.a = temp1;
                  main.b = temp2;
              } else {
                  main.a = temp2;
                  main.b = temp1;
              }
          }
      }
  
      /**
       * Expected 4 barriers for the Serial GC and 8 for G1 (4 pre + 4 post).
       */
      @Test
      public void test3() throws Exception {
          testHelper("test3Snippet", config.useG1GC ? 8 : 4);
      }
  
      public static void test3Snippet() {
          Container[] main = new Container[10];
          Container temp1 = new Container();
          Container temp2 = new Container();
          for (int i = 0; i < 10; i++) {
              main[i].a = main[i].b = temp1;
          }
  
          for (int i = 0; i < 10; i++) {
              main[i].a = main[i].b = temp2;
          }
      }
  
      /**
       * Expected 2 barriers for the Serial GC and 5 for G1 (3 pre + 2 post) The (2 or 4) barriers are
       * emitted while initializing the fields of the WeakReference instance. The extra pre barrier of
       * G1 concerns the read of the referent field.
       */
      @Test
      public void test4() throws Exception {
          testHelper("test4Snippet", config.useG1GC ? 5 : 2);
      }
  
      public static Object test4Snippet() {
          WeakReference<Object> weakRef = new WeakReference<>(new Object());
          return weakRef.get();
      }
  
      static WeakReference<Object> wr = new WeakReference<>(new Object());
      static Container con = new Container();
  
      /**
       * Expected 4 barriers for the Serial GC and 9 for G1 (1 ref + 4 pre + 4 post). In this test, we
       * load the correct offset of the WeakReference object so naturally we assert the presence of
       * the pre barrier.
       */
      @Test
      public void test5() throws Exception {
          testHelper("test5Snippet", config.useG1GC ? 1 : 0);
      }
  
      public static Object test5Snippet() throws Exception {
          return UNSAFE.getObject(wr, config(null).useCompressedOops ? 12L : 16L);
      }
  
      /**
       * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely
       * load the java.lang.ref.Reference.referent field so the pre barier has to be executed.
       */
      @Test
      public void test6() throws Exception {
          test2("testUnsafeLoad", UNSAFE, wr, new Long(referentOffset), null);
      }
  
      /**
       * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely
       * load a matching offset of a wrong object so the pre barier must not be executed.
       */
      @Test
      public void test7() throws Exception {
          test2("testUnsafeLoad", UNSAFE, con, new Long(referentOffset), null);
      }
  
      /**
       * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely
       * load a non-matching offset field of the java.lang.ref.Reference object so the pre barier must
       * not be executed.
       */
      @Test
      public void test8() throws Exception {
          test2("testUnsafeLoad", UNSAFE, wr, new Long(config.useCompressedOops ? 20 : 32), null);
      }
  
      /**
       * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely
       * load a matching offset+disp field of the java.lang.ref.Reference object so the pre barier
       * must be executed.
       */
      @Test
      public void test10() throws Exception {
          test2("testUnsafeLoad", UNSAFE, wr, new Long(config.useCompressedOops ? 6 : 8), new Integer(config.useCompressedOops ? 6 : 8));
      }
  
      /**
       * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely
       * load a non-matching offset+disp field of the java.lang.ref.Reference object so the pre barier
       * must not be executed.
       */
      @Test
      public void test9() throws Exception {
          test2("testUnsafeLoad", UNSAFE, wr, new Long(config.useCompressedOops ? 10 : 16), new Integer(config.useCompressedOops ? 10 : 16));
      }
  
      static Object[] src = new Object[1];
      static Object[] dst = new Object[1];
  
      static {
          for (int i = 0; i < src.length; i++) {
              src[i] = new Object();
          }
          for (int i = 0; i < dst.length; i++) {
              dst[i] = new Object();
          }
      }
  
      public static void testArrayCopy(Object a, Object b, Object c) throws Exception {
          System.arraycopy(a, 0, b, 0, (int) c);
      }
  
      @Test
      public void test11() throws Exception {
          test2("testArrayCopy", src, dst, dst.length);
      }
  
      public static Object testUnsafeLoad(Unsafe theUnsafe, Object a, Object b, Object c) throws Exception {
          final int offset = (c == null ? 0 : ((Integer) c).intValue());
          final long displacement = (b == null ? 0 : ((Long) b).longValue());
          return theUnsafe.getObject(a, offset + displacement);
      }
  
      private HotSpotInstalledCode getInstalledCode(String name, boolean withUnsafePrefix) throws Exception {
          final ResolvedJavaMethod javaMethod = withUnsafePrefix ? getResolvedJavaMethod(WriteBarrierAdditionTest.class, name, Unsafe.class, Object.class, Object.class, Object.class)
                          : getResolvedJavaMethod(WriteBarrierAdditionTest.class, name, Object.class, Object.class, Object.class);
          final HotSpotInstalledCode installedCode = (HotSpotInstalledCode) getCode(javaMethod);
          return installedCode;
      }
  
      @SuppressWarnings("try")
      private void testHelper(final String snippetName, final int expectedBarriers) throws Exception, SecurityException {
          ResolvedJavaMethod snippet = getResolvedJavaMethod(snippetName);
          try (Scope s = Debug.scope("WriteBarrierAdditionTest", snippet)) {
              StructuredGraph graph = parseEager(snippet, AllowAssumptions.NO);
              HighTierContext highContext = getDefaultHighTierContext();
              MidTierContext midContext = new MidTierContext(getProviders(), getTargetProvider(), OptimisticOptimizations.ALL, graph.getProfilingInfo());
              new InliningPhase(new InlineEverythingPolicy(), new CanonicalizerPhase()).apply(graph, highContext);
              new CanonicalizerPhase().apply(graph, highContext);
              new LoweringPhase(new CanonicalizerPhase(), LoweringTool.StandardLoweringStage.HIGH_TIER).apply(graph, highContext);
              new GuardLoweringPhase().apply(graph, midContext);
              new LoweringPhase(new CanonicalizerPhase(), LoweringTool.StandardLoweringStage.MID_TIER).apply(graph, midContext);
              new WriteBarrierAdditionPhase(config).apply(graph);
              Debug.dump(Debug.BASIC_LOG_LEVEL, graph, "After Write Barrier Addition");
  
              int barriers = 0;
              if (config.useG1GC) {
                  barriers = graph.getNodes().filter(G1ReferentFieldReadBarrier.class).count() + graph.getNodes().filter(G1PreWriteBarrier.class).count() +
                                  graph.getNodes().filter(G1PostWriteBarrier.class).count();
              } else {
                  barriers = graph.getNodes().filter(SerialWriteBarrier.class).count();
              }
              if (expectedBarriers != barriers) {
                  Assert.assertEquals(getScheduledGraphString(graph), expectedBarriers, barriers);
              }
              for (WriteNode write : graph.getNodes().filter(WriteNode.class)) {
                  if (config.useG1GC) {
                      if (write.getBarrierType() != BarrierType.NONE) {
                          Assert.assertEquals(1, write.successors().count());
                          Assert.assertTrue(write.next() instanceof G1PostWriteBarrier);
                          Assert.assertTrue(write.predecessor() instanceof G1PreWriteBarrier);
                      }
                  } else {
                      if (write.getBarrierType() != BarrierType.NONE) {
                          Assert.assertEquals(1, write.successors().count());
                          Assert.assertTrue(write.next() instanceof SerialWriteBarrier);
                      }
                  }
              }
  
              for (ReadNode read : graph.getNodes().filter(ReadNode.class)) {
  