--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.jvmci.code/src/com/oracle/jvmci/code/Register.java	Wed May 27 00:36:16 2015 +0200
@@ -0,0 +1,241 @@
+/*
+ * Copyright (c) 2009, 2014, 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 com.oracle.jvmci.code;
+
+import com.oracle.jvmci.meta.*;
+
+/**
+ * Represents a target machine register.
+ */
+public final class Register implements Comparable<Register> {
+
+    public static final RegisterCategory SPECIAL = new RegisterCategory("SPECIAL");
+
+    /**
+     * Invalid register.
+     */
+    public static final Register None = new Register(-1, -1, "noreg", SPECIAL);
+
+    /**
+     * Frame pointer of the current method. All spill slots and outgoing stack-based arguments are
+     * addressed relative to this register.
+     */
+    public static final Register Frame = new Register(-2, -2, "framereg", SPECIAL);
+
+    public static final Register CallerFrame = new Register(-3, -3, "callerframereg", SPECIAL);
+
+    /**
+     * The identifier for this register that is unique across all the registers in a
+     * {@link Architecture}. A valid register has {@code number > 0}.
+     */
+    public final int number;
+
+    /**
+     * The mnemonic of this register.
+     */
+    public final String name;
+
+    /**
+     * The actual encoding in a target machine instruction for this register, which may or may not
+     * be the same as {@link #number}.
+     */
+    public final int encoding;
+
+    /**
+     * The assembler calls this method to get the register's encoding.
+     */
+    public int encoding() {
+        return encoding;
+    }
+
+    /**
+     * A platform specific register category that describes which values can be stored in a
+     * register.
+     */
+    private final RegisterCategory registerCategory;
+
+    /**
+     * A platform specific register type that describes which values can be stored in a register.
+     */
+    public static class RegisterCategory {
+
+        private final String name;
+
+        private final int referenceMapOffset;
+        private final int referenceMapShift;
+
+        public RegisterCategory(String name) {
+            this(name, 0, 0);
+        }
+
+        public RegisterCategory(String name, int referenceMapOffset) {
+            this(name, referenceMapOffset, 0);
+        }
+
+        public RegisterCategory(String name, int referenceMapOffset, int referenceMapShift) {
+            this.name = name;
+            this.referenceMapOffset = referenceMapOffset;
+            this.referenceMapShift = referenceMapShift;
+        }
+
+        @Override
+        public String toString() {
+            return name;
+        }
+
+        @Override
+        public int hashCode() {
+            return 23 + name.hashCode();
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (obj instanceof RegisterCategory) {
+                RegisterCategory that = (RegisterCategory) obj;
+                return this.referenceMapOffset == that.referenceMapOffset && this.referenceMapShift == that.referenceMapShift && this.name.equals(that.name);
+            }
+            return false;
+        }
+    }
+
+    /**
+     * Creates a {@link Register} instance.
+     *
+     * @param number unique identifier for the register
+     * @param encoding the target machine encoding for the register
+     * @param name the mnemonic name for the register
+     * @param registerCategory the register category
+     */
+    public Register(int number, int encoding, String name, RegisterCategory registerCategory) {
+        this.number = number;
+        this.name = name;
+        this.registerCategory = registerCategory;
+        this.encoding = encoding;
+    }
+
+    public RegisterCategory getRegisterCategory() {
+        return registerCategory;
+    }
+
+    /**
+     * Get the start index of this register in the {@link ReferenceMap}.
+     */
+    public int getReferenceMapIndex() {
+        return (encoding << registerCategory.referenceMapShift) + registerCategory.referenceMapOffset;
+    }
+
+    /**
+     * Gets this register as a {@linkplain RegisterValue value} with a specified kind.
+     *
+     * @param kind the specified kind
+     * @return the {@link RegisterValue}
+     */
+    public RegisterValue asValue(LIRKind kind) {
+        return new RegisterValue(kind, this);
+    }
+
+    /**
+     * Gets this register as a {@linkplain RegisterValue value} with no particular kind.
+     *
+     * @return a {@link RegisterValue} with {@link Kind#Illegal} kind.
+     */
+    public RegisterValue asValue() {
+        return asValue(LIRKind.Illegal);
+    }
+
+    /**
+     * Determines if this is a valid register.
+     *
+     * @return {@code true} iff this register is valid
+     */
+    public boolean isValid() {
+        return number >= 0;
+    }
+
+    /**
+     * Gets the maximum register {@linkplain #number number} in a given set of registers.
+     *
+     * @param registers the set of registers to process
+     * @return the maximum register number for any register in {@code registers}
+     */
+    public static int maxRegisterNumber(Register[] registers) {
+        int max = Integer.MIN_VALUE;
+        for (Register r : registers) {
+            if (r.number > max) {
+                max = r.number;
+            }
+        }
+        return max;
+    }
+
+    /**
+     * Gets the maximum register {@linkplain #encoding encoding} in a given set of registers.
+     *
+     * @param registers the set of registers to process
+     * @return the maximum register encoding for any register in {@code registers}
+     */
+    public static int maxRegisterEncoding(Register[] registers) {
+        int max = Integer.MIN_VALUE;
+        for (Register r : registers) {
+            if (r.encoding > max) {
+                max = r.encoding;
+            }
+        }
+        return max;
+    }
+
+    @Override
+    public String toString() {
+        return name;
+    }
+
+    @Override
+    public int compareTo(Register o) {
+        if (number < o.number) {
+            return -1;
+        }
+        if (number > o.number) {
+            return 1;
+        }
+        return 0;
+    }
+
+    @Override
+    public int hashCode() {
+        return 17 + name.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj instanceof Register) {
+            Register other = (Register) obj;
+            if (number == other.number) {
+                assert name.equals(other.name);
+                assert encoding == other.encoding;
+                assert registerCategory.equals(other.registerCategory);
+                return true;
+            }
+        }
+        return false;
+    }
+}