gcc/testsuite/gcc.dg/tree-ssa/predcom-5.c

   1 /* { dg-do compile } */
   2 /* { dg-do run } */
   3 /* { dg-options "-O2 -fpredictive-commoning -fdump-tree-pcom-details" } */
   4
   5 /* Test for predictive commoning of expressions, with reassociation.  */
   6
   7 void abort (void);
   8
   9 unsigned a[1000], b[1000], c[1000], d[1000];
  10
  11 int main(void)
  12 {
  13   unsigned i;
  14
  15   for (i = 0; i < 1000; i++)
  16     a[i] = b[i] = d[i] = i;
  17
  18   for (i = 1; i < 998; i++)
  19     c[i] = d[i + 1] * a[i + 2] * b[i + 1] - b[i - 1] * a[i] * d[i - 1];
  20
  21   for (i = 1; i < 998; i++)
  22     if (c[i] != (i+1)*(i+2)*(i+1) - (i - 1) * i * (i - 1))
  23       abort ();
  24
  25   return 0;
  26 }
  27
  28 /* { dg-final { scan-tree-dump-times "Combination" 2 "pcom"} } */
  29 /* { dg-final { scan-tree-dump-times "Unrolling 3 times." 1 "pcom"} } */
  30 /* { dg-final { cleanup-tree-dump "pcom" } } */