[Bug c/60090] For expression without ~, gcc -O1 emits "comparison of promoted ~unsigned with unsigned"

[mpolacek at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60090

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2014-02-06
                 CC|                            |mpolacek at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
This (and a bunch of other related PRs) is about early folding in the FE.  
c_fully_fold when optimize calls fold_build2 -> fold_binary_loc that transforms
the expression and then we issue those seemingly unrelated warnings.  I'd say
that while we want the exprs to be folded, we should issue diagnostics for the
unfolded exprs.  (I think it's been discussed numerous times in the past.)

Nothing for stage4, but we/I should address this in gcc 5.0.