--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.debug/src/org/graalvm/compiler/debug/internal/KeyRegistry.java	2017-02-15 16:58:27.410219552 -0800
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2012, 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.debug.internal;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Registry for allocating a globally unique integer id to each {@link DebugValue}.
+ */
+public class KeyRegistry {
+
+    private static final Map<String, Integer> keyMap = new HashMap<>();
+    private static final List<DebugValue> debugValues = new ArrayList<>();
+
+    /**
+     * Ensures a given debug value is registered.
+     *
+     * @return the globally unique id for {@code value}
+     */
+    public static synchronized int register(DebugValue value) {
+        String name = value.getName();
+        if (!keyMap.containsKey(name)) {
+            keyMap.put(name, debugValues.size());
+            debugValues.add(value);
+        }
+        return keyMap.get(name);
+    }
+
+    /**
+     * Gets a immutable view of the registered debug values.
+     *
+     * @return a list where {@code get(i).getIndex() == i}
+     */
+    public static synchronized List<DebugValue> getDebugValues() {
+        return Collections.unmodifiableList(debugValues);
+    }
+}