[Bug rtl-optimization/57300] [4.8/4.9 Regression] statement in expression miscompiled at -O3 in 32-bit mode

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57300

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
The alternative could be, if dead_or_set_p is going to be so rare even in the
near future, to just introduce split_dead_or_set_p wrapper around it, which
would do something like:
  if (df_note == NULL)
    {
      df_note_add_problem ();
      df_analyze ();
    }
  return dead_or_set_p (...);
Not sure if it is safe to run df_analyze when the cfg is gone (split5 pass), if
not, then this wrapper should detect that and just return conservatively false.