1  /* Set floating-point environment exception handling.
       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_libc.h>
      20  
      21  int
      22  __fesetexceptflag (const fexcept_t *flagp, int excepts)
      23  {
      24    fenv_union_t u, n;
      25    fexcept_t flag;
      26  
      27    /* Get the current state.  */
      28    u.fenv = fegetenv_register ();
      29  
      30    /* Ignore exceptions not listed in 'excepts'.  */
      31    flag = *flagp & excepts;
      32  
      33    /* Replace the exception status */
      34    int excepts_mask = FPSCR_STICKY_BITS & excepts;
      35    if ((excepts & FE_INVALID) != 0)
      36      excepts_mask |= FE_ALL_INVALID;
      37    n.l = ((u.l & ~excepts_mask)
      38  	 | (flag & FPSCR_STICKY_BITS)
      39  	 /* Turn FE_INVALID into FE_INVALID_SOFTWARE.  */
      40  	 | (flag >> ((31 - FPSCR_VX) - (31 - FPSCR_VXSOFT))
      41  	    & FE_INVALID_SOFTWARE));
      42  
      43    /* Store the new status word (along with the rest of the environment).
      44       This may cause floating-point exceptions if the restored state
      45       requests it.  */
      46    if (n.l != u.l)
      47      fesetenv_register (n.fenv);
      48  
      49    /* Deal with FE_INVALID_SOFTWARE not being implemented on some chips.  */
      50    if (flag & FE_INVALID)
      51      feraiseexcept(FE_INVALID);
      52  
      53    /* Success.  */
      54    return 0;
      55  }
      56  
      57  #include <shlib-compat.h>
      58  #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
      59  strong_alias (__fesetexceptflag, __old_fesetexceptflag)
      60  compat_symbol (libm, __old_fesetexceptflag, fesetexceptflag, GLIBC_2_1);
      61  #endif
      62  
      63  versioned_symbol (libm, __fesetexceptflag, fesetexceptflag, GLIBC_2_2);