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 <math.h>
      22  
      23  int
      24  __feraiseexcept (int excepts)
      25  {
      26    /* Raise exceptions represented by EXCEPTS.  But we must raise only one
      27       signal at a time.  It is important that if the overflow/underflow
      28       exception and the divide by zero exception are given at the same
      29       time, the overflow/underflow exception follows the divide by zero
      30       exception.  */
      31  
      32    /* First: invalid exception.  */
      33    if (excepts & FE_INVALID)
      34      {
      35        /* One example of an invalid operation is 0 * Infinity.  */
      36        double d = HUGE_VAL;
      37        __asm__ __volatile__ ("fmul%.s %#0r0,%0; fnop" : "=f" (d) : "0" (d));
      38      }
      39  
      40    /* Next: division by zero.  */
      41    if (excepts & FE_DIVBYZERO)
      42      {
      43        double d = 1.0;
      44        __asm__ __volatile__ ("fdiv%.s %#0r0,%0; fnop" : "=f" (d) : "0" (d));
      45      }
      46  
      47    /* Next: overflow.  */
      48    if (excepts & FE_OVERFLOW)
      49      {
      50        long double d = LDBL_MAX;
      51  
      52        __asm__ __volatile__ ("fmul%.x %0,%0; fnop" : "=f" (d) : "0" (d));
      53      }
      54  
      55    /* Next: underflow.  */
      56    if (excepts & FE_UNDERFLOW)
      57      {
      58        long double d = -LDBL_MAX;
      59  
      60        __asm__ __volatile__ ("fetox%.x %0; fnop" : "=f" (d) : "0" (d));
      61      }
      62  
      63    /* Last: inexact.  */
      64    if (excepts & FE_INEXACT)
      65      {
      66        long double d = 1.0;
      67        __asm__ __volatile__ ("fdiv%.s %#0r3,%0; fnop" : "=f" (d) : "0" (d));
      68      }
      69  
      70    /* Success.  */
      71    return 0;
      72  }
      73  
      74  #include <shlib-compat.h>
      75  #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
      76  strong_alias (__feraiseexcept, __old_feraiseexcept)
      77  compat_symbol (libm, __old_feraiseexcept, feraiseexcept, GLIBC_2_1);
      78  #endif
      79  
      80  libm_hidden_def (__feraiseexcept)
      81  libm_hidden_ver (__feraiseexcept, feraiseexcept)
      82  versioned_symbol (libm, __feraiseexcept, feraiseexcept, GLIBC_2_2);