--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jvmci/jdk.vm.ci.code/src/jdk/vm/ci/code/RegisterAttributes.java	Thu Oct 08 17:28:41 2015 -0700
@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2010, 2011, 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;
+
+/**
+ * A collection of register attributes. The specific attribute values for a register may be local to
+ * a compilation context. For example, a {@link RegisterConfig} in use during a compilation will
+ * determine which registers are callee saved.
+ */
+public class RegisterAttributes {
+
+    private final boolean callerSave;
+    private final boolean calleeSave;
+    private final boolean allocatable;
+
+    public RegisterAttributes(boolean isCallerSave, boolean isCalleeSave, boolean isAllocatable) {
+        this.callerSave = isCallerSave;
+        this.calleeSave = isCalleeSave;
+        this.allocatable = isAllocatable;
+    }
+
+    public static final RegisterAttributes NONE = new RegisterAttributes(false, false, false);
+
+    /**
+     * Creates a map from register {@linkplain Register#number numbers} to register
+     * {@linkplain RegisterAttributes attributes} for a given register configuration and set of
+     * registers.
+     *
+     * @param registerConfig a register configuration
+     * @param registers a set of registers
+     * @return an array whose length is the max register number in {@code registers} plus 1. An
+     *         element at index i holds the attributes of the register whose number is i.
+     */
+    public static RegisterAttributes[] createMap(RegisterConfig registerConfig, Register[] registers) {
+        RegisterAttributes[] map = new RegisterAttributes[registers.length];
+        for (Register reg : registers) {
+            if (reg != null) {
+                Register[] csr = registerConfig.getCalleeSaveRegisters();
+                RegisterAttributes attr = new RegisterAttributes(Arrays.asList(registerConfig.getCallerSaveRegisters()).contains(reg), csr == null ? false : Arrays.asList(csr).contains(reg),
+                                Arrays.asList(registerConfig.getAllocatableRegisters()).contains(reg));
+                if (map.length <= reg.number) {
+                    map = Arrays.copyOf(map, reg.number + 1);
+                }
+                map[reg.number] = attr;
+            }
+        }
+        for (int i = 0; i < map.length; i++) {
+            if (map[i] == null) {
+                map[i] = NONE;
+            }
+        }
+        return map;
+    }
+
+    /**
+     * @return Denotes a register that is available for use by a register allocator.
+     */
+    public boolean isAllocatable() {
+        return allocatable;
+    }
+
+    /**
+     * @return Denotes a register whose value preservation (if required) across a call is the
+     *         responsibility of the callee.
+     */
+    public boolean isCalleeSave() {
+        return calleeSave;
+    }
+
+    /**
+     * @return Denotes a register whose value preservation (if required) across a call is the
+     *         responsibility of the caller.
+     */
+    public boolean isCallerSave() {
+        return callerSave;
+    }
+}