1 /*
   2  * Copyright (c) 2000, 2002, 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,
  20  * CA 94065 USA or visit www.oracle.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 package sun.jvm.hotspot.asm;
  26 
  27 /** <P> Register is an abstraction over machine registers. </P>
  28 
  29     <P> FIXME: should align constants with underlying VM code </P> */
  30 
  31 public abstract class Register extends ImmediateOrRegister {
  32   /** Corresponds to the machine register code. -1 stands for invalid
  33       register (initial value). */
  34   protected int number;
  35 
  36   public Register() {
  37     number = -1;
  38   }
  39 
  40   public Register(int number) {
  41     this.number = number;
  42   }
  43 
  44   /** Must be overridden by subclass to indicate number of available
  45       registers on this platform */
  46   public abstract int getNumberOfRegisters();
  47 
  48   public boolean isValid() {
  49     return ((0 <= number) && (number <= getNumberOfRegisters()));
  50   }
  51 
  52   public int getNumber() {
  53     return number;
  54   }
  55 
  56   public boolean equals(Object x) {
  57     if (x == null) {
  58       return false;
  59     }
  60 
  61     if (!getClass().equals(x.getClass())) {
  62       return false;
  63     }
  64 
  65     Register reg = (Register) x;
  66 
  67     return (reg.getNumber() == getNumber());
  68   }
  69 
  70   public int hashCode() {
  71     return number;
  72   }
  73 
  74   public boolean isRegister() {
  75     return true;
  76   }
  77 
  78   public abstract boolean isStackPointer();
  79   public abstract boolean isFramePointer();
  80   public abstract boolean isFloat();
  81 }