old-autovect-branch/gcc/testsuite/gcc.c-torture/execute/ieee/mul-subnormal-single-1.c

   1 /* Check that certain subnormal numbers (formerly known as denormalized
   2    numbers) are rounded to within 0.5 ulp.  PR other/14354.  */
   3
   4 /* This test requires that float and unsigned int are the same size and
   5    that the sign-bit of the float is at MSB of the unsigned int.  */
   6
   7 #if __INT_MAX__ != 2147483647L
   8 int main () { exit (0); }
   9 #else
  10
  11 union uf
  12 {
  13   unsigned int u;
  14   float f;
  15 };
  16
  17 static float
  18 u2f (unsigned int v)
  19 {
  20   union uf u;
  21   u.u = v;
  22   return u.f;
  23 }
  24
  25 static unsigned int
  26 f2u (float v)
  27 {
  28   union uf u;
  29   u.f = v;
  30   return u.u;
  31 }
  32
  33 int ok = 1;
  34
  35 static void
  36 tstmul (unsigned int ux, unsigned int uy, unsigned int ur)
  37 {
  38   float x = u2f (ux);
  39   float y = u2f (uy);
  40
  41   if (f2u (x * y) != ur)
  42     /* Set a variable rather than aborting here, to simplify tracing when
  43        several computations are wrong.  */
  44     ok = 0;
  45 }
  46
  47 /* We don't want to make this const and static, or else we risk inlining
  48    causing the test to fold as constants at compile-time.  */
  49 struct
  50 {
  51   unsigned int p1, p2, res;
  52 } expected[] =
  53   {
  54     {0xfff, 0x3f800400, 0xfff},
  55     {0xf, 0x3fc88888, 0x17},
  56     {0xf, 0x3f844444, 0xf}
  57   };
  58
  59 int
  60 main (int argc, char *argv[], char *envp[])
  61 {
  62   unsigned int i;
  63
  64   for (i = 0; i < sizeof (expected) / sizeof (expected[0]); i++)
  65     {
  66       tstmul (expected[i].p1, expected[i].p2, expected[i].res);
  67       tstmul (expected[i].p2, expected[i].p1, expected[i].res);
  68     }
  69
  70   if (!ok)
  71     abort ();
  72
  73   exit (0);
  74 }
  75 #endif