glibc/sysdeps/ieee754/float128/ieee754_float128.h

141 lines
3.8 KiB
C

/* _Float128 IEEE like macros.
Copyright (C) 2017-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _IEEE754_FLOAT128_H
#define _IEEE754_FLOAT128_H
#include <endian.h>
#include <stdint.h>
# if __FLOAT_WORD_ORDER == BIG_ENDIAN
# define __FLT_EORDER2(t, a, b) t a; t b;
# define __FLT_EORDER4(t, a, b, c, d) \
t a; t b; t c; t d;
# define __FLT_EORDER6(t, a, b, c, d, e, f) \
t a; t b; t c; t d; t e; t f;
# define __FLT_EORDER7(t, a, b, c, d, e, f, g) \
t a; t b; t c; t d; t e; t f; t g;
# else
# define __FLT_EORDER2(t, a, b) \
t b; t a;
# define __FLT_EORDER4(t, a, b, c, d) \
t d; t c; t b; t a;
# define __FLT_EORDER6(t, a, b, c, d, e, f) \
t f; t e; t d; t c; t b; t a;
# define __FLT_EORDER7(t, a, b, c, d, e, f, g) \
t g; t f; t e; t d; t c; t b; t a;
# endif
/* A union which permits us to convert between _Float128 and
four 32 bit ints or two 64 bit ints. */
typedef union
{
_Float128 value;
struct
{
__FLT_EORDER2 (uint64_t, msw, lsw);
} parts64;
struct
{
__FLT_EORDER4 (uint32_t, w0, w1, w2, w3);
} parts32;
} ieee854_float128_shape_type;
/* Get two 64 bit ints from a _Float128. */
# define GET_FLOAT128_WORDS64(ix0,ix1,d) \
do { \
ieee854_float128_shape_type qw_u; \
qw_u.value = (d); \
(ix0) = qw_u.parts64.msw; \
(ix1) = qw_u.parts64.lsw; \
} while (0)
/* Set a _Float128 from two 64 bit ints. */
# define SET_FLOAT128_WORDS64(d,ix0,ix1) \
do { \
ieee854_float128_shape_type qw_u; \
qw_u.parts64.msw = (ix0); \
qw_u.parts64.lsw = (ix1); \
(d) = qw_u.value; \
} while (0)
/* Get the more significant 64 bits of a _Float128 mantissa. */
# define GET_FLOAT128_MSW64(v,d) \
do { \
ieee854_float128_shape_type sh_u; \
sh_u.value = (d); \
(v) = sh_u.parts64.msw; \
} while (0)
/* Set the more significant 64 bits of a _Float128 mantissa from an int. */
# define SET_FLOAT128_MSW64(d,v) \
do { \
ieee854_float128_shape_type sh_u; \
sh_u.value = (d); \
sh_u.parts64.msw = (v); \
(d) = sh_u.value; \
} while (0)
/* Get the least significant 64 bits of a _Float128 mantissa. */
# define GET_FLOAT128_LSW64(v,d) \
do { \
ieee854_float128_shape_type sh_u; \
sh_u.value = (d); \
(v) = sh_u.parts64.lsw; \
} while (0)
/* Likewise, some helper macros which are exposed via ieee754.h for
C99 real types, but not _Float128. */
union ieee854_float128
{
_Float128 d;
/* This is the IEEE 854 quad-precision format. */
struct
{
__FLT_EORDER6 (unsigned int, negative:1,
exponent:15,
mantissa0:16,
mantissa1:32,
mantissa2:32,
mantissa3:32)
} ieee;
/* This format makes it easier to see if a NaN is a signalling NaN. */
struct
{
__FLT_EORDER7 (unsigned int, negative:1,
exponent:15,
quiet_nan:1,
mantissa0:15,
mantissa1:32,
mantissa2:32,
mantissa3:32)
} ieee_nan;
};
#define IEEE854_FLOAT128_BIAS 0x3fff /* Added to exponent. */
#endif