1  /* Set floating-point environment exception handling.
       2     Copyright (C) 2000-2023 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_libc.h>
      20  #include <math.h>
      21  #include <fpu_control.h>
      22  
      23  int
      24  fesetexceptflag (const fexcept_t *flagp, int excepts)
      25  {
      26    fexcept_t fpc, fpc_new;
      27  
      28    /* Get the current environment.  We have to do this since we cannot
      29       separately set the status word.  */
      30    _FPU_GETCW (fpc);
      31  
      32    /* Clear the current exception bits.  */
      33    fpc_new = fpc & ~((excepts & FE_ALL_EXCEPT) << FPC_FLAGS_SHIFT);
      34    if ((fpc & FPC_NOT_FPU_EXCEPTION) == 0)
      35      /* Bits 6, 7 of dxc-byte are zero,
      36         thus bits 0-5 of dxc-byte correspond to the flag-bits.
      37         Clear given exceptions in dxc-field.  */
      38      fpc_new &= ~((excepts & FE_ALL_EXCEPT) << FPC_DXC_SHIFT);
      39  
      40    /* Set exceptions from flagp in flags-field.  */
      41    fpc_new |= (*flagp & excepts & FE_ALL_EXCEPT) << FPC_FLAGS_SHIFT;
      42  
      43    /* Store the new status word (along with the rest of the environment.
      44       Possibly new exceptions are set but they won't get executed.  */
      45    _FPU_SETCW (fpc_new);
      46  
      47    /* Success.  */
      48    return 0;
      49  }