001/*
002 * Copyright (c) 2009, 2014, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package jdk.internal.jvmci.code;
024
025import jdk.internal.jvmci.meta.*;
026
027/**
028 * Denotes a register that stores a value of a fixed kind. There is exactly one (canonical) instance
029 * of {@link RegisterValue} for each ({@link Register}, {@link Kind}) pair. Use
030 * {@link Register#asValue(LIRKind)} to retrieve the canonical {@link RegisterValue} instance for a
031 * given (register,kind) pair.
032 */
033public final class RegisterValue extends AllocatableValue {
034
035    private final Register reg;
036
037    /**
038     * Should only be called from {@link Register#Register} to ensure canonicalization.
039     */
040    protected RegisterValue(LIRKind kind, Register register) {
041        super(kind);
042        this.reg = register;
043    }
044
045    @Override
046    public String toString() {
047        return getRegister().name + getKindSuffix();
048    }
049
050    /**
051     * @return the register that contains the value
052     */
053    public Register getRegister() {
054        return reg;
055    }
056
057    @Override
058    public int hashCode() {
059        return 29 * super.hashCode() + reg.hashCode();
060    }
061
062    @Override
063    public boolean equals(Object obj) {
064        if (obj instanceof RegisterValue) {
065            RegisterValue other = (RegisterValue) obj;
066            return super.equals(obj) && reg.equals(other.reg);
067        }
068        return false;
069    }
070}