text: /* Raise given exceptions.
     Copyright (C) 2001-2020 Free Software Foundation, Inc.
     This file is part of the GNU C Library.
  
     The GNU C Library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Lesser General Public
     License as published by the Free Software Foundation; either
     version 2.1 of the License, or (at your option) any later version.
  
     The GNU C Library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Lesser General Public License for more details.
  
     You should have received a copy of the GNU Lesser General Public
     License along with the GNU C Library; if not, see
     <https://www.gnu.org/licenses/>.  */
  
  #include <fenv.h>
  #include <math.h>
  
  int
  __feraiseexcept (int excepts)
  {
    /* Raise exceptions represented by EXPECTS.  But we must raise only
       one signal at a time.  It is important that if the overflow/underflow
       exception and the inexact exception are given at the same time,
       the overflow/underflow exception follows the inexact exception.  */
  
    /* First: invalid exception.  */
    if ((FE_INVALID & excepts) != 0)
      {
        /* One example of an invalid operation is 0.0 / 0.0.  */
        float f = 0.0;
  
        __asm__ __volatile__ ("divss %0, %0 " : : "x" (f));
        (void) &f;
      }
  
    /* Next: division by zero.  */
    if ((FE_DIVBYZERO & excepts) != 0)
      {
        float f = 1.0;
        float g = 0.0;
  
        __asm__ __volatile__ ("divss %1, %0" : : "x" (f), "x" (g));
        (void) &f;
      }
  
    /* Next: overflow.  */
    if ((FE_OVERFLOW & excepts) != 0)
      {
        /* XXX: Is it ok to only set the x87 FPU?  */
        /* There is no way to raise only the overflow flag.  Do it the
  	 hard way.  */
        fenv_t temp;
  
        /* Bah, we have to clear selected exceptions.  Since there is no
  	 `fldsw' instruction we have to do it the hard way.  */
        __asm__ __volatile__ ("fnstenv %0" : "=m" (*&temp));
  
        /* Set the relevant bits.  */
        temp.__status_word |= FE_OVERFLOW;
  
        /* Put the new data in effect.  */
        __asm__ __volatile__ ("fldenv %0" : : "m" (*&temp));
  
        /* And raise the exception.  */
        __asm__ __volatile__ ("fwait");
      }
  
    /* Next: underflow.  */
    if ((FE_UNDERFLOW & excepts) != 0)
      {
        /* XXX: Is it ok to only set the x87 FPU?  */
        /* There is no way to raise only the underflow flag.  Do it the
  	 hard way.  */
        fenv_t temp;
  
        /* Bah, we have to clear selected exceptions.  Since there is no
  	 `fldsw' instruction we have to do it the hard way.  */
        __asm__ __volatile__ ("fnstenv %0" : "=m" (*&temp));
  
        /* Set the relevant bits.  */
        temp.__status_word |= FE_UNDERFLOW;
  
        /* Put the new data in effect.  */
        __asm__ __volatile__ ("fldenv %0" : : "m" (*&temp));
  
        /* And raise the exception.  */
        __asm__ __volatile__ ("fwait");
      }
  
    /* Last: inexact.  */
    if ((FE_INEXACT & excepts) != 0)
      {
        /* XXX: Is it ok to only set the x87 FPU?  */
        /* There is no way to raise only the inexact flag.  Do it the
  	 hard way.  */
        fenv_t temp;
  
        /* Bah, we have to clear selected exceptions.  Since there is no
  	 `fldsw' instruction we have to do it the hard way.  */
        __asm__ __volatile__ ("fnstenv %0" : "=m" (*&temp));
  
        /* Set the relevant bits.  */
        temp.__status_word |= FE_INEXACT;
  
        /* Put the new data in effect.  */
        __asm__ __volatile__ ("fldenv %0" : : "m" (*&temp));
  
        /* And raise the exception.  */
        __asm__ __volatile__ ("fwait");
      }
  
    /* Success.  */
    return 0;
  }
  libm_hidden_def (__feraiseexcept)
  weak_alias (__feraiseexcept, feraiseexcept)
  libm_hidden_weak (feraiseexcept)
  