[Bug tree-optimization/114722] Missed optimization: !e*d*e=>0, affected by useless instructions

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114722

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2024-04-15
           Severity|normal                      |enhancement
             Status|UNCONFIRMED                 |NEW
           Keywords|                            |missed-optimization, TREE

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---

Confirmed.

Working case:
  x = c_6(D);
  _1 = e_8(D) == 0;
  _11 = e_8(D) * d_9(D);
  _4 = _1 ? _11 : 0;

vs not working case:

  x = c_5(D);
  _1 = e_10(D) == 0;
  _3 = _1 ? d_7(D) : 0;
  _4 = _3 * e_10(D);


In the first case, the rtl optimizers can figure it out back to 0. While in the
second case, it can't. 

Not a regression and has only been improved lately.