gcc/testsuite/gcc.dg/extract_recip_4.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-Ofast -fdump-tree-optimized-raw" } */
   3
   4 /* Don't expect any of these divisions to be extracted.  */
   5 double f (double x, int p)
   6 {
   7   if (p > 0)
   8     {
   9       return 1.0/(x * x);
  10     }
  11
  12   if (p > -1)
  13     {
  14       return x * x * x;
  15     }
  16   return  1.0 /(x);
  17 }
  18
  19 /* Expect a reciprocal to be extracted here.  */
  20 double g (double *a, double x, double y)
  21 {
  22   *a = 3 / y;
  23   double k = x / (y * y);
  24
  25   if (y * y == 2.0)
  26     return k + 1 / y;
  27   else
  28     return k - 1 / y;
  29 }
  30
  31 /* Expect 2 divisions in 'f' and 1 in 'g'.  */
  32 /* { dg-final { scan-tree-dump-times "rdiv_expr" 3 "optimized" } } */
  33 /* Expect 3 multiplications in 'f' and 4 in 'g'.  */
  34 /* { dg-final { scan-tree-dump-times "mult_expr" 7 "optimized" } } */