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/* $NetBSD: ieee754.h,v 1.17 2020/04/16 22:13:51 christos 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(/*CONSTCOND*/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_ */
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