[Bug tree-optimization/110743] Unexpected -ftrivial-auto-var-init=pattern behavior with partial bitfields

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110743

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
The vectorizer turns this into

  layer_masks = .DEFERRED_INIT (20, 1, &"layer_masks"[0]);
  vect__1.5_14 = MEM <vector(2) long int> [(struct layer_masks *)&layer_masks];
  vect__2.6_15 = vect__1.5_14 & { 545460846719, 545460846719 };
  MEM <vector(2) long int> [(struct layer_masks *)&layer_masks] = vect__2.6_15;
  _5 = MEM <int> [(struct layer_masks *)&layer_masks + 16B];
  _6 = _5 & 127;
  MEM <int> [(struct layer_masks *)&layer_masks + 16B] = _6;
  security_add_hooks (&layer_masks);