/* Install given floating-point environment and raise exceptions.

   Copyright (C) 1997-2018 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);