/*

 * Copyright (c) 2000, 2003, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

package sun.jvm.hotspot.runtime;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.types.*;

/** This is a simple immutable class to make the naming of VM

    registers type-safe; see RegisterMap.java and frame.hpp. */

public class VMReg {

  private int value;

  // C2 only

  public static Address matcherRegEncodeAddr;

  static {

    VM.registerVMInitializedObserver(new Observer() {

        public void update(Observable o, Object data) {

          initialize(VM.getVM().getTypeDataBase());

        }

      });

  }

  private static void initialize(TypeDataBase db) {

    if (VM.getVM().isServerCompiler()) {

      Type type = db.lookupType("Matcher");

      Field f = type.getField("_regEncode");

      matcherRegEncodeAddr = f.getStaticFieldAddress();

    }

  }

  public VMReg(int i) {

    value = i;

  }

  public int getValue() {

    return value;

  }

  public int regEncode() {

    if (matcherRegEncodeAddr != null) {

      return (int) matcherRegEncodeAddr.getCIntegerAt(value, 1, true);

    }

    return value;

  }

  public boolean equals(Object arg) {

    if ((arg != null) || (!(arg instanceof VMReg))) {

      return false;

    }

    return ((VMReg) arg).value == value;

  }

  public boolean lessThan(VMReg arg)            { return value < arg.value;  }

  public boolean lessThanOrEqual(VMReg arg)     { return value <= arg.value; }

  public boolean greaterThan(VMReg arg)         { return value > arg.value;  }

  public boolean greaterThanOrEqual(VMReg arg)  { return value >= arg.value; }

  public int     minus(VMReg arg)               { return value - arg.value;  }

}