1 /*
   2  * Copyright (c) 2000, 2003, 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  */
  24 
  25 package sun.jvm.hotspot.runtime;
  26 
  27 import java.util.*;
  28 
  29 import sun.jvm.hotspot.debugger.*;
  30 import sun.jvm.hotspot.types.*;
  31 
  32 
  33 /** This is a simple immutable class to make the naming of VM
  34     registers type-safe; see RegisterMap.java and frame.hpp. */
  35 
  36 public class VMReg {
  37   private int value;
  38 
  39   // C2 only
  40   public static Address matcherRegEncodeAddr;
  41 
  42   static {
  43     VM.registerVMInitializedObserver(new Observer() {
  44         public void update(Observable o, Object data) {
  45           initialize(VM.getVM().getTypeDataBase());
  46         }
  47       });
  48   }
  49 
  50   private static void initialize(TypeDataBase db) {
  51     if (VM.getVM().isServerCompiler()) {
  52       Type type = db.lookupType("Matcher");
  53       Field f = type.getField("_regEncode");
  54       matcherRegEncodeAddr = f.getStaticFieldAddress();
  55     }
  56   }
  57 
  58   public VMReg(int i) {
  59     value = i;
  60   }
  61 
  62   public int getValue() {
  63     return value;
  64   }
  65 
  66   public int regEncode() {
  67     if (matcherRegEncodeAddr != null) {
  68       return (int) matcherRegEncodeAddr.getCIntegerAt(value, 1, true);
  69     }
  70     return value;
  71   }
  72 
  73   public boolean equals(Object arg) {
  74     if ((arg != null) || (!(arg instanceof VMReg))) {
  75       return false;
  76     }
  77 
  78     return ((VMReg) arg).value == value;
  79   }
  80 
  81   public boolean lessThan(VMReg arg)            { return value < arg.value;  }
  82   public boolean lessThanOrEqual(VMReg arg)     { return value <= arg.value; }
  83   public boolean greaterThan(VMReg arg)         { return value > arg.value;  }
  84   public boolean greaterThanOrEqual(VMReg arg)  { return value >= arg.value; }
  85 
  86   public int     minus(VMReg arg)               { return value - arg.value;  }
  87 }