mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-24 11:41:07 +00:00
68 lines
2.6 KiB
C
68 lines
2.6 KiB
C
/* Install given floating-point environment and raise exceptions.
|
|
Copyright (C) 1997-2013 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
|
|
|
|
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/>. */
|
|
|
|
#include <fenv_libc.h>
|
|
#include <fpu_control.h>
|
|
|
|
#define _FPU_MASK_ALL (_FPU_MASK_ZM | _FPU_MASK_OM | _FPU_MASK_UM | _FPU_MASK_XM | _FPU_MASK_IM)
|
|
|
|
int
|
|
__feupdateenv (const fenv_t *envp)
|
|
{
|
|
fenv_union_t old, new;
|
|
|
|
/* Save the currently set exceptions. */
|
|
new.fenv = *envp;
|
|
old.fenv = fegetenv_register ();
|
|
|
|
/* Restore rounding mode and exception enable from *envp and merge
|
|
exceptions. Leave fraction rounded/inexact and FP result/CC bits
|
|
unchanged. */
|
|
new.l[1] = (old.l[1] & 0x1FFFFF00) | (new.l[1] & 0x1FF80FFF);
|
|
|
|
/* If the old env has no enabled exceptions and the new env has any enabled
|
|
exceptions, then unmask SIGFPE in the MSR FE0/FE1 bits. This will put
|
|
the hardware into "precise mode" and may cause the FPU to run slower on
|
|
some hardware. */
|
|
if ((old.l[1] & _FPU_MASK_ALL) == 0 && (new.l[1] & _FPU_MASK_ALL) != 0)
|
|
(void)__fe_nomask_env ();
|
|
|
|
/* If the old env had any enabled exceptions and the new env has no enabled
|
|
exceptions, then mask SIGFPE in the MSR FE0/FE1 bits. This may allow the
|
|
FPU to run faster because it always takes the default action and can not
|
|
generate SIGFPE. */
|
|
if ((old.l[1] & _FPU_MASK_ALL) != 0 && (new.l[1] & _FPU_MASK_ALL) == 0)
|
|
(void)__fe_mask_env ();
|
|
|
|
/* Atomically enable and raise (if appropriate) exceptions set in `new'. */
|
|
fesetenv_register (new.fenv);
|
|
|
|
/* Success. */
|
|
return 0;
|
|
}
|
|
|
|
#include <shlib-compat.h>
|
|
#if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
|
|
strong_alias (__feupdateenv, __old_feupdateenv)
|
|
compat_symbol (libm, __old_feupdateenv, feupdateenv, GLIBC_2_1);
|
|
#endif
|
|
|
|
libm_hidden_ver (__feupdateenv, feupdateenv)
|
|
versioned_symbol (libm, __feupdateenv, feupdateenv, GLIBC_2_2);
|