--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.code/src/jdk/vm/ci/code/RegisterArray.java	2017-02-15 16:55:30.186473769 -0800
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 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 jdk.vm.ci.code;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * An immutable ordered list of registers. Only required because Java lacks immutable arrays.
+ */
+public final class RegisterArray implements Iterable<Register> {
+
+    private final Register[] registers;
+    private int hash;
+
+    public RegisterArray(Register... registers) {
+        this.registers = registers;
+    }
+
+    public RegisterArray(Collection<Register> registers) {
+        this.registers = registers.toArray(new Register[registers.size()]);
+    }
+
+    /**
+     * Gets the number of registers.
+     */
+    public int size() {
+        return registers.length;
+    }
+
+    /**
+     * Gets the register at a given index.
+     *
+     * @param index the index of the register to retrieve
+     */
+    public Register get(int index) {
+        return registers[index];
+    }
+
+    public void addTo(Collection<Register> collection) {
+        collection.addAll(Arrays.asList(registers));
+    }
+
+    /**
+     * Gets an immutable view of the registers as a list.
+     */
+    public List<Register> asList() {
+        return Collections.unmodifiableList(Arrays.asList(registers));
+    }
+
+    /**
+     * Gets a copy of the registers as an array.
+     */
+    public Register[] toArray() {
+        return registers.clone();
+    }
+
+    public Iterator<Register> iterator() {
+        return Arrays.asList(registers).iterator();
+    }
+
+    @Override
+    public int hashCode() {
+        if (hash == 0 && registers.length > 0) {
+            hash = Arrays.hashCode(registers);
+        }
+        return hash;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj instanceof RegisterArray) {
+            return Arrays.equals(registers, ((RegisterArray) obj).registers);
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return Arrays.toString(registers);
+    }
+}