/* 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.h>

#include <fpu_control.h>

#include <arm-features.h>

int

__feupdateenv (const fenv_t *envp)

{

  fpu_control_t fpscr, new_fpscr, updated_fpscr;

  int excepts;

  /* Fail if a VFP unit isn't present.  */

  if (!ARM_HAVE_VFP)

    return 1;

  _FPU_GETCW (fpscr);

  excepts = fpscr & FE_ALL_EXCEPT;

  if ((envp != FE_DFL_ENV) && (envp != FE_NOMASK_ENV))

    {

      /* Merge current exception flags with the saved fenv.  */

      new_fpscr = envp->__cw | excepts;

      /* Write new FPSCR if different (ignoring NZCV flags).  */

      if (((fpscr ^ new_fpscr) & ~_FPU_MASK_NZCV) != 0)

	_FPU_SETCW (new_fpscr);

      /* Raise the exceptions if enabled in the new FP state.  */

      if (excepts & (new_fpscr >> FE_EXCEPT_SHIFT))

	return __feraiseexcept (excepts);

      return 0;

    }

  /* Preserve the reserved FPSCR flags.  */

  new_fpscr = fpscr & (_FPU_RESERVED | FE_ALL_EXCEPT);

  new_fpscr |= (envp == FE_DFL_ENV) ? _FPU_DEFAULT : _FPU_IEEE;

  if (((new_fpscr ^ fpscr) & ~_FPU_MASK_NZCV) != 0)

    {

      _FPU_SETCW (new_fpscr);

      /* Not all VFP architectures support trapping exceptions, so

	 test whether the relevant bits were set and fail if not.  */

      _FPU_GETCW (updated_fpscr);

      if (new_fpscr & ~updated_fpscr)

	return 1;

    }

  /* Raise the exceptions if enabled in the new FP state.  */

  if (excepts & (new_fpscr >> FE_EXCEPT_SHIFT))

    return __feraiseexcept (excepts);

  return 0;

}

libm_hidden_def (__feupdateenv)

weak_alias (__feupdateenv, feupdateenv)

libm_hidden_weak (feupdateenv)