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/* Copyright (C) 2009-2025 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
<https://www.gnu.org/licenses/>. */
#include <fenv.h>
#include <fpu_control.h>
int
__feupdateenv (const fenv_t *envp)
{
fpu_control_t fpcr;
fpu_control_t fpcr_new;
fpu_control_t updated_fpcr;
fpu_fpsr_t fpsr;
fpu_fpsr_t fpsr_new;
int excepts;
_FPU_GETCW (fpcr);
_FPU_GETFPSR (fpsr);
excepts = fpsr & FE_ALL_EXCEPT;
if ((envp != FE_DFL_ENV) && (envp != FE_NOMASK_ENV))
{
fpcr_new = envp->__fpcr;
fpsr_new = envp->__fpsr | excepts;
if (fpcr != fpcr_new)
_FPU_SETCW (fpcr_new);
if (fpsr != fpsr_new)
_FPU_SETFPSR (fpsr_new);
if (excepts & (fpcr_new >> FE_EXCEPT_SHIFT))
return __feraiseexcept (excepts);
return 0;
}
fpcr_new = fpcr & _FPU_RESERVED;
fpsr_new = fpsr & (_FPU_FPSR_RESERVED | FE_ALL_EXCEPT);
if (envp == FE_DFL_ENV)
{
fpcr_new |= _FPU_DEFAULT;
fpsr_new |= _FPU_FPSR_DEFAULT;
}
else
{
fpcr_new |= _FPU_FPCR_IEEE;
fpsr_new |= _FPU_FPSR_IEEE;
}
_FPU_SETFPSR (fpsr_new);
if (fpcr != fpcr_new)
{
_FPU_SETCW (fpcr_new);
/* Trapping exceptions are optional in AArch64; the relevant enable
bits in FPCR are RES0 hence the absence of support can be detected
by reading back the FPCR and comparing with the required value. */
_FPU_GETCW (updated_fpcr);
if (fpcr_new & ~updated_fpcr)
return 1;
}
if (excepts & (fpcr_new >> FE_EXCEPT_SHIFT))
return __feraiseexcept (excepts);
return 0;
}
libm_hidden_def (__feupdateenv)
weak_alias (__feupdateenv, feupdateenv)
libm_hidden_weak (feupdateenv)
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