1 /*
   2  * Copyright (c) 2014, 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 package jdk.testlibrary;
  25 
  26 /**
  27  * Common library for additional constants of the <code>Double</code> type.
  28  */
  29 public final class DoubleUtils {
  30 
  31     /**
  32      * Bias used in representing a <code>Double</code> exponent.
  33      */
  34     public static final int     EXP_BIAS        = 1023;
  35 
  36     /**
  37      * Bit mask to isolate the exponent field of a
  38      * <code>Double</code>.
  39      */
  40     public static final long    EXP_BIT_MASK    = 0x7FF0000000000000L;
  41 
  42     /**
  43      * Bit mask to isolate the sign bit of a <code>Double</code>.
  44      */
  45     public static final long    SIGN_BIT_MASK   = 0x8000000000000000L;
  46 
  47     /**
  48      * Bit mask to isolate the significand field of a
  49      * <code>Double</code>.
  50      */
  51     public static final long    SIGNIF_BIT_MASK = 0x000FFFFFFFFFFFFFL;
  52 
  53     /**
  54      * The number of logical bits in the significand of a
  55      * <code>Double</code> number, including the implicit bit.
  56      */
  57     public static final int SIGNIFICAND_WIDTH   = 53;
  58 
  59     /**
  60      * The exponent the smallest positive <code>Double</code>
  61      * subnormal value would have if it could be normalized..
  62      */
  63     public static final int     MIN_SUB_EXPONENT = Double.MIN_EXPONENT -
  64                                                    (SIGNIFICAND_WIDTH - 1);
  65 
  66 }