[Bug middle-end/108370] gcc doesn't merge bitwise-AND if an explicit comparison against 0 is given

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108370
--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Created attachment 55914
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55914&action=edit
Patch

Combined with the patch for PR 109960. We are able to optimize this correctly:
  _5 = bio_4(D)->bi_flags;
  _8 = _5 & 3;
  if (_8 != 0)
    goto <bb 3>; [66.50%]
  else
    goto <bb 4>; [33.50%]

  <bb 3> [local count: 714038312]:
  _1 = (int) mark_dirty_6(D);
  __bio_release_pages (bio_4(D), _1); [tail call]