--- a/test/hotspot/jtreg/compiler/jvmci/jdk.vm.ci.runtime.test/src/jdk/vm/ci/runtime/test/TestSpeculationLog.java	Wed May 01 12:41:26 2019 -0400
+++ b/test/hotspot/jtreg/compiler/jvmci/jdk.vm.ci.runtime.test/src/jdk/vm/ci/runtime/test/TestSpeculationLog.java	Wed May 01 12:31:29 2019 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2019, 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
@@ -24,24 +24,107 @@
  */
 package jdk.vm.ci.runtime.test;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.function.Supplier;
+
 import org.junit.Assert;
 import org.junit.Test;
 
+import jdk.vm.ci.code.CodeCacheProvider;
 import jdk.vm.ci.meta.JavaConstant;
+import jdk.vm.ci.meta.ResolvedJavaMethod;
+import jdk.vm.ci.meta.ResolvedJavaType;
 import jdk.vm.ci.meta.SpeculationLog;
+import jdk.vm.ci.meta.SpeculationLog.SpeculationReasonEncoding;
+import jdk.vm.ci.runtime.JVMCI;
 
 public class TestSpeculationLog extends MethodUniverse {
 
-    static class Dummy implements SpeculationLog.SpeculationReason {
+    static final class Dummy implements SpeculationLog.SpeculationReason {
+
+        final int[] ints = {Integer.MIN_VALUE, -42, -1, 0, 1, 42, Integer.MAX_VALUE};
+        final long[] longs = {Long.MIN_VALUE, -42, -1, 0, 1, 42, Long.MAX_VALUE};
+        final String[] strings = {null, "non-empty string", ""};
+        final Collection<ResolvedJavaMethod> methods = new ArrayList<>(MethodUniverse.methods.values()).subList(0, 10);
+        final Collection<ResolvedJavaMethod> constructors = new ArrayList<>(MethodUniverse.constructors.values()).subList(0, 10);
+        final Collection<ResolvedJavaType> types = new ArrayList<>(TypeUniverse.javaTypes).subList(0, 10);
+
+        private final boolean useCache;
+        private SpeculationReasonEncoding cachedEncoding;
+
+        Dummy(boolean useCache) {
+            this.useCache = useCache;
+        }
 
+        @Override
+        public SpeculationReasonEncoding encode(Supplier<SpeculationReasonEncoding> encodingSupplier) {
+            SpeculationReasonEncoding encoding = cachedEncoding;
+            if (encoding == null) {
+                encoding = encodingSupplier.get();
+                for (int i : ints) {
+                    encoding.addInt(i);
+                }
+                for (long l : longs) {
+                    encoding.addLong(l);
+                }
+                for (String s : strings) {
+                    encoding.addString(s);
+                }
+                for (ResolvedJavaMethod m : methods) {
+                    encoding.addMethod(m);
+                }
+                for (ResolvedJavaMethod c : constructors) {
+                    encoding.addMethod(c);
+                }
+                for (ResolvedJavaType t : types) {
+                    encoding.addType(t);
+                }
+                encoding.addMethod(null);
+                encoding.addType(null);
+            }
+            if (useCache) {
+                cachedEncoding = encoding;
+            }
+            return encoding;
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (obj instanceof Dummy) {
+                Dummy that = (Dummy) obj;
+                return Arrays.equals(this.ints, that.ints) &&
+                                Arrays.equals(this.longs, that.longs) &&
+                                Arrays.equals(this.strings, that.strings) &&
+                                this.methods.equals(that.methods) &&
+                                this.constructors.equals(that.constructors) &&
+                                this.types.equals(that.types);
+            }
+            return super.equals(obj);
+        }
+
+        @Override
+        public int hashCode() {
+            return 31 * Arrays.hashCode(ints) ^
+                            Arrays.hashCode(longs) ^
+                            Arrays.hashCode(strings) ^
+                            methods.hashCode() ^
+                            constructors.hashCode() ^
+                            types.hashCode();
+        }
     }
 
     @Test
-    public void testSpeculationIdentity() {
-        Dummy spec = new Dummy();
-        SpeculationLog log = methods.entrySet().iterator().next().getValue().getSpeculationLog();
-        SpeculationLog.Speculation s1 = log.speculate(spec);
-        SpeculationLog.Speculation s2 = log.speculate(spec);
+    public synchronized void testSpeculationIdentity() {
+        CodeCacheProvider codeCache = JVMCI.getRuntime().getHostJVMCIBackend().getCodeCache();
+        SpeculationLog log = codeCache.createSpeculationLog();
+        Dummy spec1 = new Dummy(true);
+        Dummy spec2 = new Dummy(false);
+        Assert.assertTrue(log.maySpeculate(spec1));
+        Assert.assertTrue(log.maySpeculate(spec2));
+        SpeculationLog.Speculation s1 = log.speculate(spec1);
+        SpeculationLog.Speculation s2 = log.speculate(spec2);
         Assert.assertTrue("Speculation should maintain identity", s1.equals(s2));
         JavaConstant e1 = metaAccess.encodeSpeculation(s1);
         JavaConstant e2 = metaAccess.encodeSpeculation(s2);