[Bug tree-optimization/102384] Missing optimization for pcom after enable O2 vectorization

[crazylht at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102384

--- Comment #2 from Hongtao.liu <crazylht at gmail dot com> ---
The issue also exists for -O3.

__attribute__((noinline))
void foo4 (int * a)
{
  int * _20;

  <bb 2> [local count: 10737416]:
  _20 = a_10(D) + 12;
  __builtin_memset (_20, 255, 400);
  __builtin_memset (a_10(D), 0, 400); [tail call]
  return;

}