gcc/testsuite/gcc.dg/ipa/pure-const-2.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O3 -fdump-tree-local-pure-const1 -fdump-tree-optimized" } */
   3 static __attribute__ ((noinline, noclone))
   4 int i_am_pure(char *c, int n)
   5 {
   6   char *d=__builtin_alloca (n);
   7   int i;
   8   int sum = 0;
   9   for (i=0;i<n;i++)
  10     d[i] = c[i];
  11   for (i=0;i<n;i++)
  12     d[i] *= c[n-i];
  13   for (i=0;i<n;i++)
  14     sum+=d[i];
  15   if (sum)
  16     __builtin_unreachable ();
  17   return sum;
  18 }
  19 char array[11];
  20 int
  21 main(void)
  22 {
  23   i_am_pure (array,5);
  24   i_am_pure (array,11);
  25   return 0;
  26 }
  27 /* { dg-final { scan-tree-dump "found to be pure: i_am_pure" "local-pure-const1"} } */
  28 /* { dg-final { scan-tree-dump-not "i_am_pure" "optimized"} } */