1  /* Install given floating-point environment and raise exceptions.
       2     Copyright (C) 1997-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <fenv.h>
      20  #include <unistd.h>
      21  #include <dl-procinfo.h>
      22  #include <ldsodefs.h>
      23  
      24  int
      25  __feupdateenv (const fenv_t *envp)
      26  {
      27    fexcept_t temp;
      28    unsigned int xtemp = 0;
      29  
      30    /* Save current exceptions.  */
      31    __asm__ ("fnstsw %0" : "=m" (*&temp));
      32  
      33    /* If the CPU supports SSE we test the MXCSR as well.  */
      34    if (CPU_FEATURE_USABLE (SSE))
      35      __asm__ ("stmxcsr %0" : "=m" (*&xtemp));
      36  
      37    temp = (temp | xtemp) & FE_ALL_EXCEPT;
      38  
      39    /* Install new environment.  */
      40    __fesetenv (envp);
      41  
      42    /* Raise the saved exception.  Incidentally for us the implementation
      43       defined format of the values in objects of type fexcept_t is the
      44       same as the ones specified using the FE_* constants.  */
      45    __feraiseexcept ((int) temp);
      46  
      47    /* Success.  */
      48    return 0;
      49  }
      50  
      51  #include <shlib-compat.h>
      52  #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
      53  strong_alias (__feupdateenv, __old_feupdateenv)
      54  compat_symbol (libm, __old_feupdateenv, feupdateenv, GLIBC_2_1);
      55  #endif
      56  
      57  libm_hidden_def (__feupdateenv)
      58  libm_hidden_ver (__feupdateenv, feupdateenv)
      59  versioned_symbol (libm, __feupdateenv, feupdateenv, GLIBC_2_2);