/*

 * Copyright (c) 2011, 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.

 *

 *

 */

package sun.jvm.hotspot.oops;

import java.io.*;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.runtime.*;

import sun.jvm.hotspot.types.*;

import sun.jvm.hotspot.utilities.*;

// BitData

//

// A BitData holds a flag or two in its header.

public class BitData extends ProfileData {

  // nullSeen:

  //  saw a null operand (cast/aastore/instanceof)

  static final int nullSeenFlag              = DataLayout.firstFlag + 0;

  static final int bitCellCount = 0;

  public BitData(DataLayout layout) {

    super(layout);

  }

  static int staticCellCount() {

    return bitCellCount;

  }

  public int cellCount() {

    return staticCellCount();

  }

  // Accessor

  // The nullSeen flag bit is specially known to the interpreter.

  // Consulting it allows the compiler to avoid setting up nullCheck traps.

  boolean nullSeen()     { return flagAt(nullSeenFlag); }

  // Code generation support

  // static int nullSeenByteConstant() {

  //   return flagNumberToByteConstant(nullSeenFlag);

  // }

  static int bitDataSize() {

    return cellOffset(bitCellCount);

  }

  public void printDataOn(PrintStream st) {

    printShared(st, "BitData");

  }

}