1  /* Test that exact underflow in __float128 signals the underflow
       2     exception if trapping is enabled, but does not raise the flag
       3     otherwise.  */
       4  
       5  /* { dg-do run { target i?86-*-*gnu* x86_64-*-*gnu* ia64-*-*gnu* } } */
       6  /* { dg-options "-D_GNU_SOURCE" } */
       7  /* { dg-require-effective-target fenv_exceptions } */
       8  
       9  #include <fenv.h>
      10  #include <setjmp.h>
      11  #include <signal.h>
      12  #include <stdlib.h>
      13  
      14  volatile sig_atomic_t caught_sigfpe;
      15  sigjmp_buf buf;
      16  
      17  static void
      18  handle_sigfpe (int sig)
      19  {
      20    caught_sigfpe = 1;
      21    siglongjmp (buf, 1);
      22  }
      23  
      24  int
      25  main (void)
      26  {
      27    volatile __float128 a = 0x1p-16382q, b = 0x1p-2q;
      28    volatile __float128 r;
      29    r = a * b;
      30    if (fetestexcept (FE_UNDERFLOW))
      31      abort ();
      32    if (r != 0x1p-16384q)
      33      abort ();
      34    feenableexcept (FE_UNDERFLOW);
      35    signal (SIGFPE, handle_sigfpe);
      36    if (sigsetjmp (buf, 1) == 0)
      37      r = a * b;
      38    if (!caught_sigfpe)
      39      abort ();
      40    exit (0);
      41  }