/*

 * Copyright 2003 Sun Microsystems, Inc.  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.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package sun.misc;

/**

 * This class contains additional constants documenting limits of the

 * <code>double</code> type.

 *

 * @author Joseph D. Darcy

 */

public class DoubleConsts {

    /**

     * Don't let anyone instantiate this class.

     */

    private DoubleConsts() {}

    public static final double POSITIVE_INFINITY = java.lang.Double.POSITIVE_INFINITY;

    public static final double NEGATIVE_INFINITY = java.lang.Double.NEGATIVE_INFINITY;

    public static final double NaN = java.lang.Double.NaN;

    public static final double MAX_VALUE = java.lang.Double.MAX_VALUE;

    public static final double MIN_VALUE = java.lang.Double.MIN_VALUE;

    /**

     * A constant holding the smallest positive normal value of type

     * <code>double</code>, 2<sup>-1022</sup>.  It is equal to the

     * value returned by

     * <code>Double.longBitsToDouble(0x0010000000000000L)</code>.

     *

     * @since 1.5

     */

    public static final double  MIN_NORMAL      = 2.2250738585072014E-308;

    /**

     * The number of logical bits in the significand of a

     * <code>double</code> number, including the implicit bit.

     */

    public static final int SIGNIFICAND_WIDTH   = 53;

    /**

     * Maximum exponent a finite <code>double</code> number may have.

     * It is equal to the value returned by

     * <code>Math.ilogb(Double.MAX_VALUE)</code>.

     */

    public static final int     MAX_EXPONENT    = 1023;

    /**

     * Minimum exponent a normalized <code>double</code> number may

     * have.  It is equal to the value returned by

     * <code>Math.ilogb(Double.MIN_NORMAL)</code>.

     */

    public static final int     MIN_EXPONENT    = -1022;

    /**

     * The exponent the smallest positive <code>double</code>

     * subnormal value would have if it could be normalized.  It is

     * equal to the value returned by

     * <code>FpUtils.ilogb(Double.MIN_VALUE)</code>.

     */

    public static final int     MIN_SUB_EXPONENT = MIN_EXPONENT -

                                                   (SIGNIFICAND_WIDTH - 1);

    /**

     * Bias used in representing a <code>double</code> exponent.

     */

    public static final int     EXP_BIAS        = 1023;

    /**

     * Bit mask to isolate the sign bit of a <code>double</code>.

     */

    public static final long    SIGN_BIT_MASK   = 0x8000000000000000L;

    /**

     * Bit mask to isolate the exponent field of a

     * <code>double</code>.

     */

    public static final long    EXP_BIT_MASK    = 0x7FF0000000000000L;

    /**

     * Bit mask to isolate the significand field of a

     * <code>double</code>.

     */

    public static final long    SIGNIF_BIT_MASK = 0x000FFFFFFFFFFFFFL;

    static {

        // verify bit masks cover all bit positions and that the bit

        // masks are non-overlapping

        assert(((SIGN_BIT_MASK | EXP_BIT_MASK | SIGNIF_BIT_MASK) == ~0L) &&

               (((SIGN_BIT_MASK & EXP_BIT_MASK) == 0L) &&

                ((SIGN_BIT_MASK & SIGNIF_BIT_MASK) == 0L) &&

                ((EXP_BIT_MASK & SIGNIF_BIT_MASK) == 0L)));

    }

}