Mercurial > gnulib
annotate lib/ieee754.in.h @ 40186:8964917f9574
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| author | Karl Berry <karl@freefriends.org> |
|---|---|
| date | Mon, 18 Feb 2019 08:02:49 -0800 |
| parents | b06060465f09 |
| children |
| rev | line source |
|---|---|
|
40057
b06060465f09
maint: Run 'make update-copyright'
Paul Eggert <eggert@cs.ucla.edu>
parents:
39759
diff
changeset
|
1 /* Copyright (C) 1992-2019 Free Software Foundation, Inc. |
| 39759 | 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, see | |
| 16 <http://www.gnu.org/licenses/>. */ | |
| 17 | |
| 18 #ifndef _IEEE754_H | |
| 19 | |
| 20 #define _IEEE754_H 1 | |
| 21 | |
| 22 #ifndef _GL_GNULIB_HEADER | |
| 23 /* Ordinary glibc usage. */ | |
| 24 # include <features.h> | |
| 25 # include <endian.h> | |
| 26 #else | |
| 27 /* Gnulib usage. */ | |
| 28 # ifndef __BEGIN_DECLS | |
| 29 # ifdef __cplusplus | |
| 30 # define __BEGIN_DECLS extern "C" { | |
| 31 # define __END_DECLS } | |
| 32 # else | |
| 33 # define __BEGIN_DECLS | |
| 34 # define __END_DECLS | |
| 35 # endif | |
| 36 # endif | |
| 37 # ifndef __FLOAT_WORD_ORDER | |
| 38 # define __LITTLE_ENDIAN 1234 | |
| 39 # define __BIG_ENDIAN 4321 | |
| 40 # ifdef WORDS_BIGENDIAN | |
| 41 # define __BYTE_ORDER __BIG_ENDIAN | |
| 42 # else | |
| 43 # define __BYTE_ORDER __LITTLE_ENDIAN | |
| 44 # endif | |
| 45 # define __FLOAT_WORD_ORDER __BYTE_ORDER | |
| 46 # endif | |
| 47 #endif | |
| 48 | |
| 49 __BEGIN_DECLS | |
| 50 | |
| 51 union ieee754_float | |
| 52 { | |
| 53 float f; | |
| 54 | |
| 55 /* This is the IEEE 754 single-precision format. */ | |
| 56 struct | |
| 57 { | |
| 58 #if __BYTE_ORDER == __BIG_ENDIAN | |
| 59 unsigned int negative:1; | |
| 60 unsigned int exponent:8; | |
| 61 unsigned int mantissa:23; | |
| 62 #endif /* Big endian. */ | |
| 63 #if __BYTE_ORDER == __LITTLE_ENDIAN | |
| 64 unsigned int mantissa:23; | |
| 65 unsigned int exponent:8; | |
| 66 unsigned int negative:1; | |
| 67 #endif /* Little endian. */ | |
| 68 } ieee; | |
| 69 | |
| 70 /* This format makes it easier to see if a NaN is a signalling NaN. */ | |
| 71 struct | |
| 72 { | |
| 73 #if __BYTE_ORDER == __BIG_ENDIAN | |
| 74 unsigned int negative:1; | |
| 75 unsigned int exponent:8; | |
| 76 unsigned int quiet_nan:1; | |
| 77 unsigned int mantissa:22; | |
| 78 #endif /* Big endian. */ | |
| 79 #if __BYTE_ORDER == __LITTLE_ENDIAN | |
| 80 unsigned int mantissa:22; | |
| 81 unsigned int quiet_nan:1; | |
| 82 unsigned int exponent:8; | |
| 83 unsigned int negative:1; | |
| 84 #endif /* Little endian. */ | |
| 85 } ieee_nan; | |
| 86 }; | |
| 87 | |
| 88 #define IEEE754_FLOAT_BIAS 0x7f /* Added to exponent. */ | |
| 89 | |
| 90 | |
| 91 union ieee754_double | |
| 92 { | |
| 93 double d; | |
| 94 | |
| 95 /* This is the IEEE 754 double-precision format. */ | |
| 96 struct | |
| 97 { | |
| 98 #if __BYTE_ORDER == __BIG_ENDIAN | |
| 99 unsigned int negative:1; | |
| 100 unsigned int exponent:11; | |
| 101 /* Together these comprise the mantissa. */ | |
| 102 unsigned int mantissa0:20; | |
| 103 unsigned int mantissa1:32; | |
| 104 #endif /* Big endian. */ | |
| 105 #if __BYTE_ORDER == __LITTLE_ENDIAN | |
| 106 # if __FLOAT_WORD_ORDER == __BIG_ENDIAN | |
| 107 unsigned int mantissa0:20; | |
| 108 unsigned int exponent:11; | |
| 109 unsigned int negative:1; | |
| 110 unsigned int mantissa1:32; | |
| 111 # else | |
| 112 /* Together these comprise the mantissa. */ | |
| 113 unsigned int mantissa1:32; | |
| 114 unsigned int mantissa0:20; | |
| 115 unsigned int exponent:11; | |
| 116 unsigned int negative:1; | |
| 117 # endif | |
| 118 #endif /* Little endian. */ | |
| 119 } ieee; | |
| 120 | |
| 121 /* This format makes it easier to see if a NaN is a signalling NaN. */ | |
| 122 struct | |
| 123 { | |
| 124 #if __BYTE_ORDER == __BIG_ENDIAN | |
| 125 unsigned int negative:1; | |
| 126 unsigned int exponent:11; | |
| 127 unsigned int quiet_nan:1; | |
| 128 /* Together these comprise the mantissa. */ | |
| 129 unsigned int mantissa0:19; | |
| 130 unsigned int mantissa1:32; | |
| 131 #else | |
| 132 # if __FLOAT_WORD_ORDER == __BIG_ENDIAN | |
| 133 unsigned int mantissa0:19; | |
| 134 unsigned int quiet_nan:1; | |
| 135 unsigned int exponent:11; | |
| 136 unsigned int negative:1; | |
| 137 unsigned int mantissa1:32; | |
| 138 # else | |
| 139 /* Together these comprise the mantissa. */ | |
| 140 unsigned int mantissa1:32; | |
| 141 unsigned int mantissa0:19; | |
| 142 unsigned int quiet_nan:1; | |
| 143 unsigned int exponent:11; | |
| 144 unsigned int negative:1; | |
| 145 # endif | |
| 146 #endif | |
| 147 } ieee_nan; | |
| 148 }; | |
| 149 | |
| 150 #define IEEE754_DOUBLE_BIAS 0x3ff /* Added to exponent. */ | |
| 151 | |
| 152 | |
| 153 union ieee854_long_double | |
| 154 { | |
| 155 long double d; | |
| 156 | |
| 157 /* This is the IEEE 854 double-extended-precision format. */ | |
| 158 struct | |
| 159 { | |
| 160 #if __BYTE_ORDER == __BIG_ENDIAN | |
| 161 unsigned int negative:1; | |
| 162 unsigned int exponent:15; | |
| 163 unsigned int empty:16; | |
| 164 unsigned int mantissa0:32; | |
| 165 unsigned int mantissa1:32; | |
| 166 #endif | |
| 167 #if __BYTE_ORDER == __LITTLE_ENDIAN | |
| 168 # if __FLOAT_WORD_ORDER == __BIG_ENDIAN | |
| 169 unsigned int exponent:15; | |
| 170 unsigned int negative:1; | |
| 171 unsigned int empty:16; | |
| 172 unsigned int mantissa0:32; | |
| 173 unsigned int mantissa1:32; | |
| 174 # else | |
| 175 unsigned int mantissa1:32; | |
| 176 unsigned int mantissa0:32; | |
| 177 unsigned int exponent:15; | |
| 178 unsigned int negative:1; | |
| 179 unsigned int empty:16; | |
| 180 # endif | |
| 181 #endif | |
| 182 } ieee; | |
| 183 | |
| 184 /* This is for NaNs in the IEEE 854 double-extended-precision format. */ | |
| 185 struct | |
| 186 { | |
| 187 #if __BYTE_ORDER == __BIG_ENDIAN | |
| 188 unsigned int negative:1; | |
| 189 unsigned int exponent:15; | |
| 190 unsigned int empty:16; | |
| 191 unsigned int one:1; | |
| 192 unsigned int quiet_nan:1; | |
| 193 unsigned int mantissa0:30; | |
| 194 unsigned int mantissa1:32; | |
| 195 #endif | |
| 196 #if __BYTE_ORDER == __LITTLE_ENDIAN | |
| 197 # if __FLOAT_WORD_ORDER == __BIG_ENDIAN | |
| 198 unsigned int exponent:15; | |
| 199 unsigned int negative:1; | |
| 200 unsigned int empty:16; | |
| 201 unsigned int mantissa0:30; | |
| 202 unsigned int quiet_nan:1; | |
| 203 unsigned int one:1; | |
| 204 unsigned int mantissa1:32; | |
| 205 # else | |
| 206 unsigned int mantissa1:32; | |
| 207 unsigned int mantissa0:30; | |
| 208 unsigned int quiet_nan:1; | |
| 209 unsigned int one:1; | |
| 210 unsigned int exponent:15; | |
| 211 unsigned int negative:1; | |
| 212 unsigned int empty:16; | |
| 213 # endif | |
| 214 #endif | |
| 215 } ieee_nan; | |
| 216 }; | |
| 217 | |
| 218 #define IEEE854_LONG_DOUBLE_BIAS 0x3fff | |
| 219 | |
| 220 __END_DECLS | |
| 221 | |
| 222 #endif /* ieee754.h */ |