gcc/testsuite/gcc.dg/recip_sqrt_mult_1.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-Ofast -fdump-tree-recip" } */
   3
   4 double res, res2, tmp;
   5 void
   6 foo (double a, double b)
   7 {
   8   tmp = 1.0 / __builtin_sqrt (a);
   9   res = tmp * tmp;
  10   res2 = a * tmp;
  11 }
  12
  13 /* { dg-final { scan-tree-dump "Optimizing reciprocal sqrt multiplications" "recip" } } */
  14 /* { dg-final { scan-tree-dump "Replacing squaring multiplication" "recip" } } */
  15 /* { dg-final { scan-tree-dump "Replacing original division" "recip" } } */