https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66773
--- Comment #4 from Daniel Marjamäki <daniel.marjamaki at gmail dot com> --- absolutely. there are often bugs in the boundaries. well. I was hoping to get more optimistic response. how about this.. imagine that we wrote a "possible division by zero" warning for every integer division that uses a non-constant rhs. every warning where rhs can't really be zero would be a false positive. That would be very noisy imo. imho the false positive rate should be similar here. If there is a comparison 'a == -1' and a is unsigned then this warning is useless if a can't be 0xffffffff. if a has arbitrary values then statistically it's as likely that a is 0xffffffff and 0. So I guess the false positive rate is somewhat similar. Maybe the message can be tweaked? comparison between signed and unsigned integer expressions [-Wsign-compare] I think this message is fine for relational comparisons. A sign-cast is a reasonable solution. For == and != I am afraid the message is somewhat misleading. A sign-cast is not a good solution.
