[Bug tree-optimization/88280] missing folding of logical and bitwise AND

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88280

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2018-11-30
            Version|unknown                     |9.0
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  g and h end up like this before RTL expansion (initial folding
produces this):

  j_6 = i_4(D) & a_5(D);
  _1 = i_4(D) != 0;
  _2 = j_6 != 0;
  _3 = _1 & _2;
  _7 = (int) _3;
  return _7;

and for e we do not combine the i != 0 check.

  <bb 2> [local count: 1073741824]:
  if (i_3(D) != 0)
    goto <bb 3>; [50.00%]
  else
    goto <bb 4>; [50.00%]

  <bb 3> [local count: 536870913]:
  _1 = i_3(D) & a_4(D);
  _6 = _1 != 0;
  _7 = (int) _6;

  <bb 4> [local count: 1073741824]:
  # iftmp.0_2 = PHI <_7(3), i_3(D)(2)>
  return iftmp.0_2;