--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.lir/src/org/graalvm/compiler/lir/util/RegisterMap.java	2017-02-15 17:06:03.297092946 -0800
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2016, 2016, 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.lir.util;
+
+import java.util.function.BiConsumer;
+
+import jdk.vm.ci.code.Architecture;
+import jdk.vm.ci.code.Register;
+import jdk.vm.ci.code.RegisterArray;
+
+public class RegisterMap<T> {
+    private final Object[] values;
+    private final Architecture architecture;
+
+    public RegisterMap(Architecture arch) {
+        assert checkArchitecture(arch);
+        this.values = new Object[arch.getRegisters().size()];
+        this.architecture = arch;
+    }
+
+    @SuppressWarnings("unchecked")
+    public T get(Register reg) {
+        return (T) values[index(reg)];
+    }
+
+    public void remove(Register reg) {
+        values[index(reg)] = null;
+    }
+
+    public void put(Register reg, T value) {
+        values[index(reg)] = value;
+    }
+
+    @SuppressWarnings("unchecked")
+    public void forEach(BiConsumer<? super Register, ? super T> consumer) {
+        for (int i = 0; i < values.length; ++i) {
+            T value = (T) values[i];
+            if (value != null) {
+                consumer.accept(architecture.getRegisters().get(i), value);
+            }
+        }
+    }
+
+    private static int index(Register reg) {
+        return reg.number;
+    }
+
+    private static boolean checkArchitecture(Architecture arch) {
+        RegisterArray registers = arch.getRegisters();
+        for (int i = 0; i < registers.size(); ++i) {
+            assert registers.get(i).number == i : registers.get(i) + ": " + registers.get(i).number + "!=" + i;
+        }
+        return true;
+    }
+}