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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  }