[Bug tree-optimization/104543] [12 Regression] wrong code at -O3 on x86_64-linux-gnu

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104543

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2022-02-15
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed.
>From what I could tell it is the unroll and jam pass which is messing up.


-fno-loop-unroll-and-jam

  <bb 5> [local count: 542102826]:
  # c.4_21 = PHI <0(7), _9(23)>
  _7 = a[c.4_21];
  _8 = _7 ^ 1;
  a[c.4_21] = _8;
  _9 = c.4_21 + 1;
  _11 = b_lsm.13_13 + 1;
  if (_11 <= 2)
    goto <bb 22>; [83.33%]
  else
    goto <bb 8>; [16.67%]

  <bb 22> [local count: 451752355]:
  a[c.4_21] = _7;