Blame sysdeps/arm/fesetenv.c

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/* Install given floating-point environment.
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   Copyright (C) 2004-2018 Free Software Foundation, Inc.
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   This file is part of the GNU C Library.
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   The GNU C Library is free software; you can redistribute it and/or
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   modify it under the terms of the GNU Lesser General Public
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   License as published by the Free Software Foundation; either
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   version 2.1 of the License, or (at your option) any later version.
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   The GNU C Library is distributed in the hope that it will be useful,
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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   Lesser General Public License for more details.
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   You should have received a copy of the GNU Lesser General Public
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   License along with the GNU C Library.  If not, see
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   <http://www.gnu.org/licenses/>.  */
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#include <fenv.h>
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#include <fpu_control.h>
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#include <arm-features.h>
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int
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__fesetenv (const fenv_t *envp)
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{
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  fpu_control_t fpscr, new_fpscr, updated_fpscr;
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  /* Fail if a VFP unit isn't present.  */
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  if (!ARM_HAVE_VFP)
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    return 1;
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  _FPU_GETCW (fpscr);
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  if ((envp != FE_DFL_ENV) && (envp != FE_NOMASK_ENV))
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    {
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      /* The new FPSCR is valid, so don't merge the reserved flags.  */
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      new_fpscr = envp->__cw;
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      /* Write new FPSCR if different (ignoring NZCV flags).  */
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      if (((fpscr ^ new_fpscr) & ~_FPU_MASK_NZCV) != 0)
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	_FPU_SETCW (new_fpscr);
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      return 0;
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    }
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  /* Preserve the reserved FPSCR flags.  */
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  new_fpscr = fpscr & _FPU_RESERVED;
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  new_fpscr |= (envp == FE_DFL_ENV) ? _FPU_DEFAULT : _FPU_IEEE;
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  if (((new_fpscr ^ fpscr) & ~_FPU_MASK_NZCV) != 0)
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    {
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      _FPU_SETCW (new_fpscr);
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      /* Not all VFP architectures support trapping exceptions, so
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	 test whether the relevant bits were set and fail if not.  */
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      _FPU_GETCW (updated_fpscr);
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      return new_fpscr & ~updated_fpscr;
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    }
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  return 0;
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}
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libm_hidden_def (__fesetenv)
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weak_alias (__fesetenv, fesetenv)
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libm_hidden_weak (fesetenv)