mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-22 13:00:06 +00:00
48 lines
1.7 KiB
C
48 lines
1.7 KiB
C
/* Narrow floating-point values to their semantic type.
|
|
Copyright (C) 2015-2020 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 _MATH_NARROW_EVAL_H
|
|
#define _MATH_NARROW_EVAL_H 1
|
|
|
|
#include <float.h>
|
|
|
|
/* math_narrow_eval reduces its floating-point argument to the range
|
|
and precision of its semantic type. (The original evaluation may
|
|
still occur with excess range and precision, so the result may be
|
|
affected by double rounding.) */
|
|
#if FLT_EVAL_METHOD == 0
|
|
# define math_narrow_eval(x) (x)
|
|
#else
|
|
# if FLT_EVAL_METHOD == 1
|
|
# define excess_precision(type) __builtin_types_compatible_p (type, float)
|
|
# else
|
|
# define excess_precision(type) (__builtin_types_compatible_p (type, float) \
|
|
|| __builtin_types_compatible_p (type, \
|
|
double))
|
|
# endif
|
|
# define math_narrow_eval(x) \
|
|
({ \
|
|
__typeof (x) math_narrow_eval_tmp = (x); \
|
|
if (excess_precision (__typeof (math_narrow_eval_tmp))) \
|
|
__asm__ ("" : "+m" (math_narrow_eval_tmp)); \
|
|
math_narrow_eval_tmp; \
|
|
})
|
|
#endif
|
|
|
|
#endif /* math-narrow-eval.h */
|