[Bug tree-optimization/95923] Failure to optimize bool checks into and

pinskia at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Sat Aug 7 07:41:11 GMT 2021


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95923

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-08-07
     Ever confirmed|0                           |1
           Assignee|unassigned at gcc dot gnu.org      |pinskia at gcc dot gnu.org
             Status|UNCONFIRMED                 |ASSIGNED

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Mine.
  _1 = ~a_6(D);
  _3 = _1 & b_7(D);
  if (_3 != 0)
    goto <bb 5>; [34.00%]
  else
    goto <bb 4>; [66.00%]

  <bb 4> [local count: 467721933]:
  _10 = _1 | b_7(D);

  <bb 5> [local count: 1073741824]:
  # _5 = PHI <0(3), _10(4), 0(2)>

This is _3 ? 0 : _10 -> (_10 & ~3)

And then this simplifies more.


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