1 /*
   2  * Copyright (c) 2009, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package jdk.vm.ci.code;
  24 
  25 import jdk.vm.ci.meta.*;
  26 
  27 /**
  28  * Denotes a register that stores a value of a fixed kind. There is exactly one (canonical) instance
  29  * of {@link RegisterValue} for each ({@link Register}, {@link JavaKind}) pair. Use
  30  * {@link Register#asValue(LIRKind)} to retrieve the canonical {@link RegisterValue} instance for a
  31  * given (register,kind) pair.
  32  */
  33 public final class RegisterValue extends AllocatableValue {
  34 
  35     private final Register reg;
  36 
  37     /**
  38      * Should only be called from {@link Register#Register} to ensure canonicalization.
  39      */
  40     protected RegisterValue(LIRKind kind, Register register) {
  41         super(kind);
  42         this.reg = register;
  43     }
  44 
  45     @Override
  46     public String toString() {
  47         return getRegister().name + getKindSuffix();
  48     }
  49 
  50     /**
  51      * @return the register that contains the value
  52      */
  53     public Register getRegister() {
  54         return reg;
  55     }
  56 
  57     @Override
  58     public int hashCode() {
  59         return 29 * super.hashCode() + reg.hashCode();
  60     }
  61 
  62     @Override
  63     public boolean equals(Object obj) {
  64         if (obj instanceof RegisterValue) {
  65             RegisterValue other = (RegisterValue) obj;
  66             return super.equals(obj) && reg.equals(other.reg);
  67         }
  68         return false;
  69     }
  70 }