sysdeps/ieee754/ldbl-128ibm/ieee754.h

   1 /* Copyright (C) 1992, 1995, 1996, 1999, 2004, 2006
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _IEEE754_H
  21
  22 #define _IEEE754_H 1
  23 #include <features.h>
  24
  25 #include <endian.h>
  26
  27 __BEGIN_DECLS
  28
  29 union ieee754_float
  30   {
  31     float f;
  32
  33     /* This is the IEEE 754 single-precision format.  */
  34     struct
  35       {
  36 #if     __BYTE_ORDER == __BIG_ENDIAN
  37         unsigned int negative:1;
  38         unsigned int exponent:8;
  39         unsigned int mantissa:23;
  40 #endif                          /* Big endian.  */
  41 #if     __BYTE_ORDER == __LITTLE_ENDIAN
  42         unsigned int mantissa:23;
  43         unsigned int exponent:8;
  44         unsigned int negative:1;
  45 #endif                          /* Little endian.  */
  46       } ieee;
  47
  48     /* This format makes it easier to see if a NaN is a signalling NaN.  */
  49     struct
  50       {
  51 #if     __BYTE_ORDER == __BIG_ENDIAN
  52         unsigned int negative:1;
  53         unsigned int exponent:8;
  54         unsigned int quiet_nan:1;
  55         unsigned int mantissa:22;
  56 #endif                          /* Big endian.  */
  57 #if     __BYTE_ORDER == __LITTLE_ENDIAN
  58         unsigned int mantissa:22;
  59         unsigned int quiet_nan:1;
  60         unsigned int exponent:8;
  61         unsigned int negative:1;
  62 #endif                          /* Little endian.  */
  63       } ieee_nan;
  64   };
  65
  66 #define IEEE754_FLOAT_BIAS      0x7f /* Added to exponent.  */
  67
  68
  69 union ieee754_double
  70   {
  71     double d;
  72
  73     /* This is the IEEE 754 double-precision format.  */
  74     struct
  75       {
  76 #if     __BYTE_ORDER == __BIG_ENDIAN
  77         unsigned int negative:1;
  78         unsigned int exponent:11;
  79         /* Together these comprise the mantissa.  */
  80         unsigned int mantissa0:20;
  81         unsigned int mantissa1:32;
  82 #endif                          /* Big endian.  */
  83 #if     __BYTE_ORDER == __LITTLE_ENDIAN
  84         /* Together these comprise the mantissa.  */
  85         unsigned int mantissa1:32;
  86         unsigned int mantissa0:20;
  87         unsigned int exponent:11;
  88         unsigned int negative:1;
  89 #endif                          /* Little endian.  */
  90       } ieee;
  91
  92     /* This format makes it easier to see if a NaN is a signalling NaN.  */
  93     struct
  94       {
  95 #if     __BYTE_ORDER == __BIG_ENDIAN
  96         unsigned int negative:1;
  97         unsigned int exponent:11;
  98         unsigned int quiet_nan:1;
  99         /* Together these comprise the mantissa.  */
 100         unsigned int mantissa0:19;
 101         unsigned int mantissa1:32;
 102 #else
 103         /* Together these comprise the mantissa.  */
 104         unsigned int mantissa1:32;
 105         unsigned int mantissa0:19;
 106         unsigned int quiet_nan:1;
 107         unsigned int exponent:11;
 108         unsigned int negative:1;
 109 #endif
 110       } ieee_nan;
 111   };
 112
 113 #define IEEE754_DOUBLE_BIAS     0x3ff /* Added to exponent.  */
 114
 115
 116 union ieee854_long_double
 117   {
 118     long double d;
 119
 120     /* This is the IEEE 854 quad-precision format.  */
 121     struct
 122       {
 123 #if     __BYTE_ORDER == __BIG_ENDIAN
 124         unsigned int negative:1;
 125         unsigned int exponent:15;
 126         /* Together these comprise the mantissa.  */
 127         unsigned int mantissa0:16;
 128         unsigned int mantissa1:32;
 129         unsigned int mantissa2:32;
 130         unsigned int mantissa3:32;
 131 #endif                          /* Big endian.  */
 132 #if     __BYTE_ORDER == __LITTLE_ENDIAN
 133         /* Together these comprise the mantissa.  */
 134         unsigned int mantissa3:32;
 135         unsigned int mantissa2:32;
 136         unsigned int mantissa1:32;
 137         unsigned int mantissa0:16;
 138         unsigned int exponent:15;
 139         unsigned int negative:1;
 140 #endif                          /* Little endian.  */
 141       } ieee;
 142
 143     /* This format makes it easier to see if a NaN is a signalling NaN.  */
 144     struct
 145       {
 146 #if     __BYTE_ORDER == __BIG_ENDIAN
 147         unsigned int negative:1;
 148         unsigned int exponent:15;
 149         unsigned int quiet_nan:1;
 150         /* Together these comprise the mantissa.  */
 151         unsigned int mantissa0:15;
 152         unsigned int mantissa1:32;
 153         unsigned int mantissa2:32;
 154         unsigned int mantissa3:32;
 155 #else
 156         /* Together these comprise the mantissa.  */
 157         unsigned int mantissa3:32;
 158         unsigned int mantissa2:32;
 159         unsigned int mantissa1:32;
 160         unsigned int mantissa0:15;
 161         unsigned int quiet_nan:1;
 162         unsigned int exponent:15;
 163         unsigned int negative:1;
 164 #endif
 165       } ieee_nan;
 166   };
 167
 168 #define IEEE854_LONG_DOUBLE_BIAS 0x3fff /* Added to exponent.  */
 169
 170
 171 /* IBM extended format for long double.
 172
 173    Each long double is made up of two IEEE doubles.  The value of the
 174    long double is the sum of the values of the two parts.  The most
 175    significant part is required to be the value of the long double
 176    rounded to the nearest double, as specified by IEEE.  For Inf
 177    values, the least significant part is required to be one of +0.0 or
 178    -0.0.  No other requirements are made; so, for example, 1.0 may be
 179    represented as (1.0, +0.0) or (1.0, -0.0), and the low part of a
 180    NaN is don't-care.  */
 181
 182 union ibm_extended_long_double
 183   {
 184     long double d;
 185     double dd[2];
 186
 187     /* This is the IBM extended format long double.  */
 188     struct
 189       { /* Big endian.  There is no other.  */
 190
 191         unsigned int negative:1;
 192         unsigned int exponent:11;
 193         /* Together Mantissa0-3 comprise the mantissa.  */
 194         unsigned int mantissa0:20;
 195         unsigned int mantissa1:32;
 196
 197         unsigned int negative2:1;
 198         unsigned int exponent2:11;
 199         /* There is an implied 1 here?  */
 200         /* Together these comprise the mantissa.  */
 201         unsigned int mantissa2:20;
 202         unsigned int mantissa3:32;
 203       } ieee;
 204    };
 205
 206 #define IBM_EXTENDED_LONG_DOUBLE_BIAS 0x3ff /* Added to exponent.  */
 207
 208 __END_DECLS
 209
 210 #endif /* ieee754.h */