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.AllocatableValue;
  26 import jdk.vm.ci.meta.JavaKind;
  27 import jdk.vm.ci.meta.LIRKind;
  28 
  29 /**
  30  * Denotes a register that stores a value of a fixed kind. There is exactly one (canonical) instance
  31  * of {@link RegisterValue} for each ({@link Register}, {@link JavaKind}) pair. Use
  32  * {@link Register#asValue(LIRKind)} to retrieve the canonical {@link RegisterValue} instance for a
  33  * given (register,kind) pair.
  34  */
  35 public final class RegisterValue extends AllocatableValue {
  36 
  37     private final Register reg;
  38 
  39     /**
  40      * Should only be called from {@link Register#Register} to ensure canonicalization.
  41      */
  42     protected RegisterValue(LIRKind kind, Register register) {
  43         super(kind);
  44         this.reg = register;
  45     }
  46 
  47     @Override
  48     public String toString() {
  49         return getRegister().name + getKindSuffix();
  50     }
  51 
  52     /**
  53      * @return the register that contains the value
  54      */
  55     public Register getRegister() {
  56         return reg;
  57     }
  58 
  59     @Override
  60     public int hashCode() {
  61         return 29 * super.hashCode() + reg.hashCode();
  62     }
  63 
  64     @Override
  65     public boolean equals(Object obj) {
  66         if (obj instanceof RegisterValue) {
  67             RegisterValue other = (RegisterValue) obj;
  68             return super.equals(obj) && reg.equals(other.reg);
  69         }
  70         return false;
  71     }
  72 }