/* $NetBSD: ieee754.h,v 1.18 2024/05/12 10:34:56 rillig Exp $ */ /* * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This software was developed by the Computer Systems Engineering group * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and * contributed to Berkeley. * * All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Lawrence Berkeley Laboratory. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)ieee.h 8.1 (Berkeley) 6/11/93 */ #ifndef _SYS_IEEE754_H_ #define _SYS_IEEE754_H_ /* * NOTICE: This is not a standalone file. To use it, #include it in * your port's ieee.h header. */ #include <machine/endian.h> /* * <sys/ieee754.h> defines the layout of IEEE 754 floating point types. * Only single-precision and double-precision types are defined here; * 128-bit long doubles are defined here IFF __HAVE_LONG_DOUBLE equals 128. * Otherwise extended types, if available, are defined in the machine-dependent * header. */ /* * Define the number of bits in each fraction and exponent. * * k k+1 * Note that 1.0 x 2 == 0.1 x 2 and that denorms are represented * * (-exp_bias+1) * as fractions that look like 0.fffff x 2 . This means that * * -126 * the number 0.10000 x 2 , for instance, is the same as the normalized * * -127 -128 * float 1.0 x 2 . Thus, to represent 2 , we need one leading zero * * -129 * in the fraction; to represent 2 , we need two, and so on. This * * (-exp_bias-fracbits+1) * implies that the smallest denormalized number is 2 * * for whichever format we are talking about: for single precision, for * * -126 -149 * instance, we get .00000000000000000000001 x 2 , or 1.0 x 2 , and * * -149 == -127 - 23 + 1. */ #define SNG_EXPBITS 8 #define SNG_FRACBITS 23 struct ieee_single { #if _BYTE_ORDER == _BIG_ENDIAN unsigned int sng_sign:1; unsigned int sng_exp:SNG_EXPBITS; unsigned int sng_frac:SNG_FRACBITS; #else unsigned int sng_frac:SNG_FRACBITS; unsigned int sng_exp:SNG_EXPBITS; unsigned int sng_sign:1; #endif }; #define DBL_EXPBITS 11 #define DBL_FRACHBITS 20 #define DBL_FRACLBITS 32 #define DBL_FRACBITS (DBL_FRACHBITS + DBL_FRACLBITS) struct ieee_double { #if _BYTE_ORDER == _BIG_ENDIAN unsigned int dbl_sign:1; unsigned int dbl_exp:DBL_EXPBITS; unsigned int dbl_frach:DBL_FRACHBITS; unsigned int dbl_fracl:DBL_FRACLBITS; #else unsigned int dbl_fracl:DBL_FRACLBITS; unsigned int dbl_frach:DBL_FRACHBITS; unsigned int dbl_exp:DBL_EXPBITS; unsigned int dbl_sign:1; #endif }; #if __HAVE_LONG_DOUBLE + 0 == 128 #define EXT_EXPBITS 15 #define EXT_FRACHBITS 48 #define EXT_FRACLBITS 64 #define EXT_FRACBITS (EXT_FRACLBITS + EXT_FRACHBITS) #define EXT_TO_ARRAY32(u, a) do { \ (a)[0] = (uint32_t)((u).extu_ext.ext_fracl >> 0); \ (a)[1] = (uint32_t)((u).extu_ext.ext_fracl >> 32); \ (a)[2] = (uint32_t)((u).extu_ext.ext_frach >> 0); \ (a)[3] = (uint32_t)((u).extu_ext.ext_frach >> 32); \ } while (0) struct ieee_ext { #if _BYTE_ORDER == _BIG_ENDIAN uint64_t ext_sign:1; uint64_t ext_exp:EXT_EXPBITS; uint64_t ext_frach:EXT_FRACHBITS; uint64_t ext_fracl; #else uint64_t ext_fracl; uint64_t ext_frach:EXT_FRACHBITS; uint64_t ext_exp:EXT_EXPBITS; uint64_t ext_sign:1; #endif }; #endif /* __HAVE_LONG_DOUBLE == 128 */ /* * Floats whose exponent is in [1..INFNAN) (of whatever type) are * `normal'. Floats whose exponent is INFNAN are either Inf or NaN. * Floats whose exponent is zero are either zero (iff all fraction * bits are zero) or subnormal values. * * At least one `signalling NaN' and one `quiet NaN' value must be * implemented. It is left to the architecture to specify how to * distinguish between these. */ #define SNG_EXP_INFNAN 255 #define DBL_EXP_INFNAN 2047 #if __HAVE_LONG_DOUBLE + 0 == 128 #define EXT_EXP_INFNAN 0x7fff #endif /* * Exponent biases. */ #define SNG_EXP_BIAS 127 #define DBL_EXP_BIAS 1023 #if __HAVE_LONG_DOUBLE + 0 == 128 #define EXT_EXP_BIAS 16383 #endif /* * Convenience data structures. */ union ieee_single_u { float sngu_f; struct ieee_single sngu_sng; }; #define sngu_sign sngu_sng.sng_sign #define sngu_exp sngu_sng.sng_exp #define sngu_frac sngu_sng.sng_frac #define SNGU_ZEROFRAC_P(u) ((u).sngu_frac != 0) union ieee_double_u { double dblu_d; struct ieee_double dblu_dbl; }; #define dblu_sign dblu_dbl.dbl_sign #define dblu_exp dblu_dbl.dbl_exp #define dblu_frach dblu_dbl.dbl_frach #define dblu_fracl dblu_dbl.dbl_fracl #define DBLU_ZEROFRAC_P(u) (((u).dblu_frach|(u).dblu_fracl) != 0) #if __HAVE_LONG_DOUBLE + 0 == 128 union ieee_ext_u { long double extu_ld; struct ieee_ext extu_ext; }; #define extu_exp extu_ext.ext_exp #define extu_sign extu_ext.ext_sign #define extu_fracl extu_ext.ext_fracl #define extu_frach extu_ext.ext_frach #define EXTU_ZEROFRAC_P(u) (((u).extu_frach|(u).extu_fracl) != 0) #ifndef LDBL_NBIT #define LDBL_IMPLICIT_NBIT 1 /* our NBIT is implicit */ #endif #endif /* __HAVE_LONG_DOUBLE */ #endif /* _SYS_IEEE754_H_ */
