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- /* Control when floating-point expressions are evaluated. Generic version.
- Copyright (C) 2007-2019 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
- <http://www.gnu.org/licenses/>. */
- #ifndef _MATH_BARRIERS_H
- #define _MATH_BARRIERS_H 1
- /* math_opt_barrier evaluates and returns its floating-point argument
- and ensures that the evaluation of any expression using the result
- of math_opt_barrier is not moved before the call. math_force_eval
- ensures that its floating-point argument is evaluated for its side
- effects even if its value is apparently unused, and that the
- evaluation of its argument is not moved after the call. Both these
- macros are used to ensure the correct ordering of floating-point
- expression evaluations with respect to accesses to the
- floating-point environment. */
- #define math_opt_barrier(x) \
- ({ __typeof (x) __x = (x); __asm ("" : "+m" (__x)); __x; })
- #define math_force_eval(x) \
- ({ __typeof (x) __x = (x); __asm __volatile__ ("" : : "m" (__x)); })
- #endif /* math-barriers.h */
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