mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-14 17:11:06 +00:00
e2239af353
Improve the commentary to aid future developers who will stumble upon this novel, yet not always perfect, mechanism to support alternative formats for long double. Likewise, rename __LONG_DOUBLE_USES_FLOAT128 to __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI now that development work has settled down. The command used was git grep -l __LONG_DOUBLE_USES_FLOAT128 ':!./ChangeLog*' | \ xargs sed -i 's/__LONG_DOUBLE_USES_FLOAT128/__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI/g' Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
54 lines
2.3 KiB
C
54 lines
2.3 KiB
C
/* Properties of long double type.
|
|
Copyright (C) 2016-2020 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 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/>. */
|
|
|
|
/* This header is included by <sys/cdefs.h>.
|
|
|
|
If long double is ABI-compatible with double, it should define
|
|
__NO_LONG_DOUBLE_MATH to 1; otherwise, it should leave
|
|
__NO_LONG_DOUBLE_MATH undefined.
|
|
|
|
If this build of the GNU C Library supports both long double
|
|
ABI-compatible with double and some other long double format not
|
|
ABI-compatible with double, it should define
|
|
__LONG_DOUBLE_MATH_OPTIONAL to 1; otherwise, it should leave
|
|
__LONG_DOUBLE_MATH_OPTIONAL undefined.
|
|
|
|
If __NO_LONG_DOUBLE_MATH is already defined, this header must not
|
|
define anything; this is needed to work with the definition of
|
|
__NO_LONG_DOUBLE_MATH in nldbl-compat.h. */
|
|
|
|
/* In the default version of this header, long double is
|
|
ABI-compatible with double. */
|
|
#ifndef __NO_LONG_DOUBLE_MATH
|
|
# define __NO_LONG_DOUBLE_MATH 1
|
|
#endif
|
|
|
|
/* The macro __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI is used to determine the
|
|
choice of the underlying ABI of long double. It will always assume
|
|
a constant value for each translation unit.
|
|
|
|
If the value is non-zero, any API which is parameterized by the long
|
|
double type (i.e the scanf/printf family of functions or the explicitly
|
|
parameterized math.h functions) will be redirected to a compatible
|
|
implementation using _Float128 ABI via symbols suffixed with ieee128.
|
|
|
|
The mechanism this macro uses to acquire may be a function
|
|
of architecture, or target specific options used to invoke the
|
|
compiler. */
|
|
#define __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI 0
|