https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96460
--- Comment #2 from Florian Weimer <fw at gcc dot gnu.org> --- (In reply to Richard Biener from comment #1) > It's perfectly valid code ... guess similar to -Wconversion though. If the modulo result is never negative, it's not *perfectly* valid because GCC has to add instructions to produce those negative values, and most programmers will never realize that this is happening.
