/*

 * Copyright (c) 2000, 2001, 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.debugger;

/** Base class for all twos-complement machine descriptions, which

    handles the cIntegerType{Min,Max}Value methods. */

public abstract class MachineDescriptionTwosComplement {

  /** Handles 1, 2, 4, and 8-byte signed integers */

  private static final long[] signedMinValues = {

    Byte.MIN_VALUE,

    Short.MIN_VALUE,

    Integer.MIN_VALUE,

    Long.MIN_VALUE

  };

  /** Handles 1, 2, 4, and 8-byte signed integers */

  private static final long[] signedMaxValues = {

    Byte.MAX_VALUE,

    Short.MAX_VALUE,

    Integer.MAX_VALUE,

    Long.MAX_VALUE

  };

  /** Handles 1, 2, and 4-byte unsigned integers properly, with a bug

      in the 8-byte unsigned integer's constant */

  private static final long[] unsignedMaxValues = {

    255L,

    65535L,

    4294967295L,

    -1L

  };

  public long cIntegerTypeMaxValue(long sizeInBytes, boolean isUnsigned) {

    if (isUnsigned) {

      // Would be nice to signal to the caller that 8-byte unsigned

      // integers are not supported properly, but it looks like doing

      // so at this level will cause problems above

      return tableLookup(sizeInBytes, unsignedMaxValues);

    } else {

      return tableLookup(sizeInBytes, signedMaxValues);

    }

  };

  public long cIntegerTypeMinValue(long sizeInBytes, boolean isUnsigned) {

    if (isUnsigned) {

      return 0;

    }

    return tableLookup(sizeInBytes, signedMinValues);

  }

  // Nearly all of the supported machines are not LP64 */

  public boolean isLP64() {

    return false;

  }

  private long tableLookup(long sizeInBytes, long[] table) {

    switch ((int) sizeInBytes) {

    case 1:

      return table[0];

    case 2:

      return table[1];

    case 4:

      return table[2];

    case 8:

      return table[3];

    default:

      throw new IllegalArgumentException("C integer type of " + sizeInBytes + " not supported");

    }

  }

}