[Bug tree-optimization/94846] Failure to optimize jnc+inc into adc

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94846

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
After r12-897 (which added a late sink pass), we get the following in
.optimized:
  if (_10 != 0)
    goto <bb 3>; [50.00%]
  else
    goto <bb 4>; [50.00%]

  <bb 3> [local count: 536870913]:
  _2 = _1 + 1;

  <bb 4> [local count: 1073741824]:
  # prephitmp_11 = PHI <_1(2), _2(3)>
  # _13 = PHI <_1(2), _2(3)>
  *p_5(D) = _13;
  return prephitmp_11;

Notice how prephitmp_11 and _13 are the same but no RTL optimizers handles
that.