--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.meta/src/jdk/vm/ci/meta/EncodedSpeculationReason.java	Thu Oct 24 16:58:39 2019 -0700
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 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
+ * 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 jdk.vm.ci.meta;
+
+import java.util.Arrays;
+import java.util.function.Supplier;
+
+import jdk.vm.ci.meta.SpeculationLog.SpeculationReason;
+
+/**
+ * An implementation of {@link SpeculationReason} based on encoded values.
+ */
+public class EncodedSpeculationReason implements SpeculationReason {
+    final int groupId;
+    final String groupName;
+    final Object[] context;
+    private SpeculationLog.SpeculationReasonEncoding encoding;
+
+    public EncodedSpeculationReason(int groupId, String groupName, Object[] context) {
+        this.groupId = groupId;
+        this.groupName = groupName;
+        this.context = context;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj instanceof EncodedSpeculationReason) {
+            if (obj instanceof EncodedSpeculationReason) {
+                EncodedSpeculationReason that = (EncodedSpeculationReason) obj;
+                return this.groupId == that.groupId && Arrays.equals(this.context, that.context);
+            }
+            return false;
+        }
+        return false;
+    }
+
+    @Override
+    public SpeculationLog.SpeculationReasonEncoding encode(Supplier<SpeculationLog.SpeculationReasonEncoding> encodingSupplier) {
+        if (encoding == null) {
+            encoding = encodingSupplier.get();
+            encoding.addInt(groupId);
+            for (Object o : context) {
+                if (o == null) {
+                    encoding.addInt(0);
+                } else {
+                    addNonNullObject(encoding, o);
+                }
+            }
+        }
+        return encoding;
+    }
+
+    static void addNonNullObject(SpeculationLog.SpeculationReasonEncoding encoding, Object o) {
+        Class<? extends Object> c = o.getClass();
+        if (c == String.class) {
+            encoding.addString((String) o);
+        } else if (c == Byte.class) {
+            encoding.addByte((Byte) o);
+        } else if (c == Short.class) {
+            encoding.addShort((Short) o);
+        } else if (c == Character.class) {
+            encoding.addShort((Character) o);
+        } else if (c == Integer.class) {
+            encoding.addInt((Integer) o);
+        } else if (c == Long.class) {
+            encoding.addLong((Long) o);
+        } else if (c == Float.class) {
+            encoding.addInt(Float.floatToRawIntBits((Float) o));
+        } else if (c == Double.class) {
+            encoding.addLong(Double.doubleToRawLongBits((Double) o));
+        } else if (o instanceof Enum) {
+            encoding.addInt(((Enum<?>) o).ordinal());
+        } else if (o instanceof ResolvedJavaMethod) {
+            encoding.addMethod((ResolvedJavaMethod) o);
+        } else if (o instanceof ResolvedJavaType) {
+            encoding.addType((ResolvedJavaType) o);
+        } else if (o instanceof ResolvedJavaField) {
+            encoding.addField((ResolvedJavaField) o);
+        } else {
+            throw new IllegalArgumentException("Unsupported type for encoding: " + c.getName());
+        }
+    }
+
+    @Override
+    public int hashCode() {
+        return groupId + Arrays.hashCode(this.context);
+    }
+
+    @Override
+    public String toString() {
+        return String.format("%s@%d%s", groupName, groupId, Arrays.toString(context));
+    }
+}