[Bug tree-optimization/118012] [avr] Expensive code (bit extract + extend + neg + and) instead of bit test

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118012

Georg-Johann Lay <gjl at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
          Component|middle-end                  |tree-optimization
   Last reconfirmed|                            |2024-12-12
     Ever confirmed|0                           |1

--- Comment #2 from Georg-Johann Lay <gjl at gcc dot gnu.org> ---
Seems like it's from tree-ssaphi optimizaton.  In gf2.c.131t.phiopt2 there is:

  <bb 3> [local count: 955630224]:
  _1 = b_5 & 1;
  _16 = _1 * a_4;
  _15 = c_7 ^ _16;

whereas in gf2.c.130t.mergephi3:

  <bb 3> [local count: 955630224]:
  _1 = b_5 & 1;
  if (_1 != 0)
    goto <bb 4>; [50.00%]
  else
    goto <bb 5>; [50.00%]

  <bb 4> [local count: 477815112]:
  c_11 = a_4 ^ c_7;

  <bb 5> [local count: 955630224]: