mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-26 23:10:06 +00:00
9ed2e15ff4
This patch continues cleaning up math_private.h by moving the math_opt_barrier and math_force_eval macros to a separate header math-barriers.h. At present, those macros are inside a "#ifndef math_opt_barrier" in math_private.h to allow architectures to override them and then use a separate math-barriers.h header, no such #ifndef or #include_next is needed; architectures just have their own alternative version of math-barriers.h when providing their own optimized versions that avoid going through memory unnecessarily. The generic math-barriers.h has a comment added to document these two macros. In this patch, math_private.h is made to #include <math-barriers.h>, so files using these macros do not need updating yet. That is because of uses of math_force_eval in math_check_force_underflow and math_check_force_underflow_nonneg, which are still defined in math_private.h. Once those are moved out to a separate header, that separate header can be made to include <math-barriers.h>, as can the other files directly using these barrier macros, and then the include of <math-barriers.h> from math_private.h can be removed. Tested for x86_64 and x86. Also tested with build-many-glibcs.py that installed stripped shared libraries are unchanged by this patch. * sysdeps/generic/math-barriers.h: New file. * sysdeps/generic/math_private.h [!math_opt_barrier] (math_opt_barrier): Move to math-barriers.h. [!math_opt_barrier] (math_force_eval): Likewise. * sysdeps/aarch64/fpu/math-barriers.h: New file. * sysdeps/aarch64/fpu/math_private.h (math_opt_barrier): Move to math-barriers.h. (math_force_eval): Likewise. * sysdeps/alpha/fpu/math-barriers.h: New file. * sysdeps/alpha/fpu/math_private.h (math_opt_barrier): Move to math-barriers.h. (math_force_eval): Likewise. * sysdeps/x86/fpu/math-barriers.h: New file. * sysdeps/i386/fpu/fenv_private.h (math_opt_barrier): Move to math-barriers.h. (math_force_eval): Likewise. * sysdeps/m68k/m680x0/fpu/math_private.h: Move to.... * sysdeps/m68k/m680x0/fpu/math-barriers.h: ... here. Adjust multiple-include guard for rename. * sysdeps/powerpc/fpu/math-barriers.h: New file. * sysdeps/powerpc/fpu/math_private.h (math_opt_barrier): Move to math-barriers.h. (math_force_eval): Likewise.
38 lines
1.7 KiB
C
38 lines
1.7 KiB
C
/* Control when floating-point expressions are evaluated. Generic version.
|
|
Copyright (C) 2007-2018 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 */
|