mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-22 04:50:07 +00:00
58 lines
1.9 KiB
C
58 lines
1.9 KiB
C
/* Set floating-point environment exception handling.
|
|
Copyright (C) 2001-2024 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/>. */
|
|
|
|
#include <fenv.h>
|
|
#include <math.h>
|
|
|
|
int
|
|
fesetexceptflag (const fexcept_t *flagp, int excepts)
|
|
{
|
|
/* The flags can be set in the 387 unit or in the SSE unit.
|
|
When we need to clear a flag, we need to do so in both units,
|
|
due to the way fetestexcept() is implemented.
|
|
When we need to set a flag, it is sufficient to do it in the SSE unit,
|
|
because that is guaranteed to not trap. */
|
|
|
|
fenv_t temp;
|
|
unsigned int mxcsr;
|
|
|
|
excepts &= FE_ALL_EXCEPT;
|
|
|
|
/* Get the current x87 FPU environment. We have to do this since we
|
|
cannot separately set the status word. */
|
|
__asm__ ("fnstenv %0" : "=m" (*&temp));
|
|
|
|
/* Clear relevant flags. */
|
|
temp.__status_word &= ~(excepts & ~ *flagp);
|
|
|
|
/* Store the new status word (along with the rest of the environment). */
|
|
__asm__ ("fldenv %0" : : "m" (*&temp));
|
|
|
|
/* And now similarly for SSE. */
|
|
__asm__ ("stmxcsr %0" : "=m" (*&mxcsr));
|
|
|
|
/* Clear or set relevant flags. */
|
|
mxcsr ^= (mxcsr ^ *flagp) & excepts;
|
|
|
|
/* Put the new data in effect. */
|
|
__asm__ ("ldmxcsr %0" : : "m" (*&mxcsr));
|
|
|
|
/* Success. */
|
|
return 0;
|
|
}
|