1  /* Disable floating-point exceptions.
       2     Copyright (C) 1999-2023 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 <ldsodefs.h>
      22  #include <dl-procinfo.h>
      23  
      24  int
      25  fedisableexcept (int excepts)
      26  {
      27    unsigned short int new_exc, old_exc;
      28  
      29    /* Get the current control word.  */
      30    __asm__ ("fstcw %0" : "=m" (*&new_exc));
      31  
      32    old_exc = (~new_exc) & FE_ALL_EXCEPT;
      33  
      34    excepts &= FE_ALL_EXCEPT;
      35  
      36    new_exc |= excepts;
      37    __asm__ ("fldcw %0" : : "m" (*&new_exc));
      38  
      39    /* If the CPU supports SSE we set the MXCSR as well.  */
      40    if (CPU_FEATURE_USABLE (SSE))
      41      {
      42        unsigned int xnew_exc;
      43  
      44        /* Get the current control word.  */
      45        __asm__ ("stmxcsr %0" : "=m" (*&xnew_exc));
      46  
      47        xnew_exc |= excepts << 7;
      48  
      49        __asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc));
      50      }
      51  
      52    return old_exc;
      53  }