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/* Install given floating-point environment and raise exceptions.
Copyright (C) 1997-2017 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 = (old.l & 0xffffffff1fffff00LL) | (new.l & 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 & _FPU_MASK_ALL) == 0 && (new.l & _FPU_MASK_ALL) != 0)
(void) __fe_nomask_env_priv ();
/* 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 & _FPU_MASK_ALL) != 0 && (new.l & _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_def (__feupdateenv)
libm_hidden_ver (__feupdateenv, feupdateenv)
versioned_symbol (libm, __feupdateenv, feupdateenv, GLIBC_2_2);
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