gcc/testsuite/gcc.dg/torture/float128-truncdf-underflow.c

   1 /* Test truncation from __float128 to double uses after-rounding
   2    tininess detection.  */
   3
   4 /* { dg-do run { target i?86-*-* x86_64-*-* ia64-*-* } } */
   5 /* { dg-options "" } */
   6 /* { dg-require-effective-target fenv_exceptions } */
   7
   8 #include <fenv.h>
   9 #include <stdlib.h>
  10
  11 int
  12 main (void)
  13 {
  14   volatile __float128 a = 0x0.fffffffffffffffp-1022q, b = 0x0.fffffffffffff8p-1022q;
  15   volatile double r;
  16   r = (double) a;
  17   if (fetestexcept (FE_UNDERFLOW))
  18     abort ();
  19   if (r != 0x1p-1022)
  20     abort ();
  21   r = (double) b;
  22   if (!fetestexcept (FE_UNDERFLOW))
  23     abort ();
  24   if (r != 0x1p-1022)
  25     abort ();
  26   exit (0);
  27 }