glibc/sysdeps/ieee754/ldbl-128/math_ldbl.h

121 lines
3.0 KiB
C

/* Manipulation of the bit representation of 'long double' quantities.
Copyright (C) 1999-2024 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 _MATH_LDBL_H_
#define _MATH_LDBL_H_ 1
#include <stdint.h>
#include <endian.h>
/* A union which permits us to convert between a long double and
four 32 bit ints or two 64 bit ints. */
#if __FLOAT_WORD_ORDER == __BIG_ENDIAN
typedef union
{
long double value;
struct
{
uint64_t msw;
uint64_t lsw;
} parts64;
struct
{
uint32_t w0, w1, w2, w3;
} parts32;
} ieee854_long_double_shape_type;
#endif
#if __FLOAT_WORD_ORDER == __LITTLE_ENDIAN
typedef union
{
long double value;
struct
{
uint64_t lsw;
uint64_t msw;
} parts64;
struct
{
uint32_t w3, w2, w1, w0;
} parts32;
} ieee854_long_double_shape_type;
#endif
/* Get two 64 bit ints from a long double. */
#define GET_LDOUBLE_WORDS64(ix0,ix1,d) \
do { \
ieee854_long_double_shape_type qw_u; \
qw_u.value = (d); \
(ix0) = qw_u.parts64.msw; \
(ix1) = qw_u.parts64.lsw; \
} while (0)
/* Set a long double from two 64 bit ints. */
#define SET_LDOUBLE_WORDS64(d,ix0,ix1) \
do { \
ieee854_long_double_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 long double mantissa. */
#define GET_LDOUBLE_MSW64(v,d) \
do { \
ieee854_long_double_shape_type sh_u; \
sh_u.value = (d); \
(v) = sh_u.parts64.msw; \
} while (0)
/* Set the more significant 64 bits of a long double mantissa from an int. */
#define SET_LDOUBLE_MSW64(d,v) \
do { \
ieee854_long_double_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 long double mantissa. */
#define GET_LDOUBLE_LSW64(v,d) \
do { \
ieee854_long_double_shape_type sh_u; \
sh_u.value = (d); \
(v) = sh_u.parts64.lsw; \
} while (0)
/*
On a platform already supporting a binary128 long double,
_Float128 will alias to long double. This transformation
makes aliasing *l functions to *f128 trivial.
*/
#define _Float128 long double
#define L(x) x##L
#endif /* math_ldbl.h */