1  /* Raise given exceptions.
       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 <float.h>
      21  #include <fpu_control.h>
      22  #include <math.h>
      23  
      24  int
      25  __feraiseexcept (int excepts)
      26  {
      27    if (excepts == 0)
      28      return 0;
      29  
      30    /* Raise exceptions represented by EXPECTS.  */
      31  
      32    if (excepts & FE_INEXACT)
      33    {
      34      double d = 1.0, x = 3.0;
      35      __asm__ __volatile__ ("fdiv %1, %0" : "+d" (d) : "d" (x));
      36    }
      37  
      38    if (excepts & FE_UNDERFLOW)
      39    {
      40      long double d = LDBL_MIN, x = 10;
      41      __asm__ __volatile__ ("fdiv %1, %0" : "+d" (d) : "d" (x));
      42    }
      43  
      44    if (excepts & FE_OVERFLOW)
      45    {
      46      long double d = LDBL_MAX;
      47      __asm__ __volatile__ ("fmul %0, %0" : "+d" (d) : "d" (d));
      48    }
      49  
      50    if (excepts & FE_DIVBYZERO)
      51    {
      52      double d = 1.0, x = 0.0;
      53      __asm__ __volatile__ ("fdiv %1, %0" : "+d" (d) : "d" (x));
      54    }
      55  
      56    if (excepts & FE_INVALID)
      57    {
      58      double d = HUGE_VAL, x = 0.0;
      59      __asm__ __volatile__ ("fmul %1, %0" : "+d" (d) : "d" (x));
      60    }
      61  
      62    {
      63      /* Restore flag fields.  */
      64      fpu_control_t cw;
      65      _FPU_GETCW (cw);
      66      cw |= (excepts & FE_ALL_EXCEPT);
      67      _FPU_SETCW (cw);
      68    }
      69  
      70    return 0;
      71  }
      72  libm_hidden_def (__feraiseexcept)
      73  weak_alias (__feraiseexcept, feraiseexcept)
      74  libm_hidden_weak (feraiseexcept)