[Bug c/37591] suppress "signed and unsigned" warnings when signed value known to be positive

["manu at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #4 from manu at gcc dot gnu dot org  2008-09-22 13:28 -------
I don't understand why this is not closed as wontfix. These warnings are coming
from the front-end. 

Unless we do one of the following:

a) some CCP and VRP in the FE, or
b) move the warnings to the middle-end,

this cannot be fixed. And the consensus seems to be that we do not want to do
either of them. And from the many problems we see with Wuninitialized, we
already know that moving the warnings to the middle-end causes a lot of
problems. Also, VRP is only enabled at -O2. And it does not work with sets,
only ranges, so the following will still not work:

adj = (flag) ? 0 : 2;
return MIN(adj, limit);

(I am sure that we have already, probably closed, a PR about this).


-- 

manu at gcc dot gnu dot org changed:

           What    |Removed                     |Added
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                 CC|                            |manu at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37591