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.h>
      20  #include <math.h>
      21  #include <unistd.h>
      22  #include <ldsodefs.h>
      23  #include <dl-procinfo.h>
      24  
      25  int
      26  __fesetexceptflag (const fexcept_t *flagp, int excepts)
      27  {
      28    fenv_t temp;
      29  
      30    /* Get the current environment.  We have to do this since we cannot
      31       separately set the status word.  */
      32    __asm__ ("fnstenv %0" : "=m" (*&temp));
      33  
      34    temp.__status_word &= ~(excepts & FE_ALL_EXCEPT);
      35    temp.__status_word |= *flagp & excepts & FE_ALL_EXCEPT;
      36  
      37    /* Store the new status word (along with the rest of the environment.
      38       Possibly new exceptions are set but they won't get executed unless
      39       the next floating-point instruction.  */
      40    __asm__ ("fldenv %0" : : "m" (*&temp));
      41  
      42    /* If the CPU supports SSE, we set the MXCSR as well.  */
      43    if (CPU_FEATURE_USABLE (SSE))
      44      {
      45        unsigned int xnew_exc;
      46  
      47        /* Get the current MXCSR.  */
      48        __asm__ ("stmxcsr %0" : "=m" (*&xnew_exc));
      49  
      50        /* Set the relevant bits.  */
      51        xnew_exc &= ~(excepts & FE_ALL_EXCEPT);
      52        xnew_exc |= *flagp & excepts & FE_ALL_EXCEPT;
      53  
      54        /* Put the new data in effect.  */
      55        __asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc));
      56      }
      57  
      58    /* Success.  */
      59    return 0;
      60  }
      61  
      62  #include <shlib-compat.h>
      63  #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
      64  strong_alias (__fesetexceptflag, __old_fesetexceptflag)
      65  compat_symbol (libm, __old_fesetexceptflag, fesetexceptflag, GLIBC_2_1);
      66  #endif
      67  
      68  versioned_symbol (libm, __fesetexceptflag, fesetexceptflag, GLIBC_2_2);