1 /* $NetBSD: ieee754.h,v 1.18 2024/05/12 10:34:56 rillig Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This software was developed by the Computer Systems Engineering group 8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 * contributed to Berkeley. 10 * 11 * All advertising materials mentioning features or use of this software 12 * must display the following acknowledgement: 13 * This product includes software developed by the University of 14 * California, Lawrence Berkeley Laboratory. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 3. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)ieee.h 8.1 (Berkeley) 6/11/93 41 */ 42 #ifndef _SYS_IEEE754_H_ 43 #define _SYS_IEEE754_H_ 44 45 /* 46 * NOTICE: This is not a standalone file. To use it, #include it in 47 * your port's ieee.h header. 48 */ 49 50 #include <machine/endian.h> 51 52 /* 53 * <sys/ieee754.h> defines the layout of IEEE 754 floating point types. 54 * Only single-precision and double-precision types are defined here; 55 * 128-bit long doubles are defined here IFF __HAVE_LONG_DOUBLE equals 128. 56 * Otherwise extended types, if available, are defined in the machine-dependent 57 * header. 58 */ 59 60 /* 61 * Define the number of bits in each fraction and exponent. 62 * 63 * k k+1 64 * Note that 1.0 x 2 == 0.1 x 2 and that denorms are represented 65 * 66 * (-exp_bias+1) 67 * as fractions that look like 0.fffff x 2 . This means that 68 * 69 * -126 70 * the number 0.10000 x 2 , for instance, is the same as the normalized 71 * 72 * -127 -128 73 * float 1.0 x 2 . Thus, to represent 2 , we need one leading zero 74 * 75 * -129 76 * in the fraction; to represent 2 , we need two, and so on. This 77 * 78 * (-exp_bias-fracbits+1) 79 * implies that the smallest denormalized number is 2 80 * 81 * for whichever format we are talking about: for single precision, for 82 * 83 * -126 -149 84 * instance, we get .00000000000000000000001 x 2 , or 1.0 x 2 , and 85 * 86 * -149 == -127 - 23 + 1. 87 */ 88 #define SNG_EXPBITS 8 89 #define SNG_FRACBITS 23 90 91 struct ieee_single { 92 #if _BYTE_ORDER == _BIG_ENDIAN 93 unsigned int sng_sign:1; 94 unsigned int sng_exp:SNG_EXPBITS; 95 unsigned int sng_frac:SNG_FRACBITS; 96 #else 97 unsigned int sng_frac:SNG_FRACBITS; 98 unsigned int sng_exp:SNG_EXPBITS; 99 unsigned int sng_sign:1; 100 #endif 101 }; 102 103 #define DBL_EXPBITS 11 104 #define DBL_FRACHBITS 20 105 #define DBL_FRACLBITS 32 106 #define DBL_FRACBITS (DBL_FRACHBITS + DBL_FRACLBITS) 107 108 struct ieee_double { 109 #if _BYTE_ORDER == _BIG_ENDIAN 110 unsigned int dbl_sign:1; 111 unsigned int dbl_exp:DBL_EXPBITS; 112 unsigned int dbl_frach:DBL_FRACHBITS; 113 unsigned int dbl_fracl:DBL_FRACLBITS; 114 #else 115 unsigned int dbl_fracl:DBL_FRACLBITS; 116 unsigned int dbl_frach:DBL_FRACHBITS; 117 unsigned int dbl_exp:DBL_EXPBITS; 118 unsigned int dbl_sign:1; 119 #endif 120 }; 121 122 #if __HAVE_LONG_DOUBLE + 0 == 128 123 124 #define EXT_EXPBITS 15 125 #define EXT_FRACHBITS 48 126 #define EXT_FRACLBITS 64 127 #define EXT_FRACBITS (EXT_FRACLBITS + EXT_FRACHBITS) 128 129 #define EXT_TO_ARRAY32(u, a) do { \ 130 (a)[0] = (uint32_t)((u).extu_ext.ext_fracl >> 0); \ 131 (a)[1] = (uint32_t)((u).extu_ext.ext_fracl >> 32); \ 132 (a)[2] = (uint32_t)((u).extu_ext.ext_frach >> 0); \ 133 (a)[3] = (uint32_t)((u).extu_ext.ext_frach >> 32); \ 134 } while (0) 135 136 struct ieee_ext { 137 #if _BYTE_ORDER == _BIG_ENDIAN 138 uint64_t ext_sign:1; 139 uint64_t ext_exp:EXT_EXPBITS; 140 uint64_t ext_frach:EXT_FRACHBITS; 141 uint64_t ext_fracl; 142 #else 143 uint64_t ext_fracl; 144 uint64_t ext_frach:EXT_FRACHBITS; 145 uint64_t ext_exp:EXT_EXPBITS; 146 uint64_t ext_sign:1; 147 #endif 148 }; 149 #endif /* __HAVE_LONG_DOUBLE == 128 */ 150 151 /* 152 * Floats whose exponent is in [1..INFNAN) (of whatever type) are 153 * `normal'. Floats whose exponent is INFNAN are either Inf or NaN. 154 * Floats whose exponent is zero are either zero (iff all fraction 155 * bits are zero) or subnormal values. 156 * 157 * At least one `signalling NaN' and one `quiet NaN' value must be 158 * implemented. It is left to the architecture to specify how to 159 * distinguish between these. 160 */ 161 #define SNG_EXP_INFNAN 255 162 #define DBL_EXP_INFNAN 2047 163 #if __HAVE_LONG_DOUBLE + 0 == 128 164 #define EXT_EXP_INFNAN 0x7fff 165 #endif 166 167 /* 168 * Exponent biases. 169 */ 170 #define SNG_EXP_BIAS 127 171 #define DBL_EXP_BIAS 1023 172 #if __HAVE_LONG_DOUBLE + 0 == 128 173 #define EXT_EXP_BIAS 16383 174 #endif 175 176 /* 177 * Convenience data structures. 178 */ 179 union ieee_single_u { 180 float sngu_f; 181 struct ieee_single sngu_sng; 182 }; 183 184 #define sngu_sign sngu_sng.sng_sign 185 #define sngu_exp sngu_sng.sng_exp 186 #define sngu_frac sngu_sng.sng_frac 187 #define SNGU_ZEROFRAC_P(u) ((u).sngu_frac != 0) 188 189 union ieee_double_u { 190 double dblu_d; 191 struct ieee_double dblu_dbl; 192 }; 193 194 #define dblu_sign dblu_dbl.dbl_sign 195 #define dblu_exp dblu_dbl.dbl_exp 196 #define dblu_frach dblu_dbl.dbl_frach 197 #define dblu_fracl dblu_dbl.dbl_fracl 198 #define DBLU_ZEROFRAC_P(u) (((u).dblu_frach|(u).dblu_fracl) != 0) 199 200 #if __HAVE_LONG_DOUBLE + 0 == 128 201 union ieee_ext_u { 202 long double extu_ld; 203 struct ieee_ext extu_ext; 204 }; 205 206 #define extu_exp extu_ext.ext_exp 207 #define extu_sign extu_ext.ext_sign 208 #define extu_fracl extu_ext.ext_fracl 209 #define extu_frach extu_ext.ext_frach 210 #define EXTU_ZEROFRAC_P(u) (((u).extu_frach|(u).extu_fracl) != 0) 211 212 #ifndef LDBL_NBIT 213 #define LDBL_IMPLICIT_NBIT 1 /* our NBIT is implicit */ 214 #endif 215 216 #endif /* __HAVE_LONG_DOUBLE */ 217 218 #endif /* _SYS_IEEE754_H_ */ 219
Indexes created Tue Sep 23 02:09:52 GMT 2025