src/ieee754-double.h

   1 /* Copyright (C) 1992, 1995, 1996, 1999 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #ifndef IEEE754_DOUBLE_H
  20 #define IEEE754_DOUBLE_H 1
  21
  22 /* Based on glibc's <ieee754.h> and modified by Ludovic Courtès to include
  23    all possible IEEE-754 double-precision representations.  */
  24
  25 /* This is the IEEE 754 double-precision format.  */
  26 union ieee754_double
  27   {
  28     double d;
  29
  30     struct
  31       {
  32         /* Big endian.  */
  33
  34         unsigned int negative:1;
  35         unsigned int exponent:11;
  36         /* Together these comprise the mantissa.  */
  37         unsigned int mantissa0:20;
  38         unsigned int mantissa1:32;
  39       } big_endian;
  40
  41     struct
  42       {
  43         /* Both byte order and word order are little endian.  */
  44
  45         /* Together these comprise the mantissa.  */
  46         unsigned int mantissa1:32;
  47         unsigned int mantissa0:20;
  48         unsigned int exponent:11;
  49         unsigned int negative:1;
  50       } little_little_endian;
  51
  52     struct
  53       {
  54         /* Byte order is little endian but word order is big endian.  Not
  55            sure this is very wide spread.  */
  56         unsigned int mantissa0:20;
  57         unsigned int exponent:11;
  58         unsigned int negative:1;
  59         unsigned int mantissa1:32;
  60       } little_big_endian;
  61
  62   };
  63
  64
  65 #endif /* ieee754-double.h */