gcc/testsuite/gcc.target/i386/brokensqrt.c

   1 /* { dg-do run } */
   2 /* { dg-options "-O2 -ffast-math -msse -mfpmath=sse -mrecip" } */
   3 /* { dg-require-effective-target sse } */
   4 #include "sse-check.h"
   5
   6 extern float sqrtf (float);
   7 float __attribute__((noinline)) broken (float a, float b)
   8 {
   9   return sqrtf (a / b);
  10 }
  11
  12 extern void abort (void);
  13 extern void *memcpy (void *, const void *, __SIZE_TYPE__);
  14 static void
  15 sse_test (void)
  16 {
  17   int i;
  18   float x;
  19   char buf[sizeof (float)];
  20   x = broken (0.0f, 10000.0f);
  21   /* A convoluted way to check for the correct result (zero) for all
  22      floating point formats.
  23      We can't use ==, !=, or range checks, or isinf/isnan/isunordered,
  24      because all of these will not do the right thing under -ffast-math,
  25      as they can assume that neither nan nor inf are returned.  */
  26   memcpy (&buf, &x, sizeof (float));
  27   for (i = 0; i < sizeof (float); i++)
  28     if (buf[i] != 0)
  29       abort ();
  30 }