https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119011
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> --- Your point that unsigned long == -1 vs. unsigned long == -1u is not the same is a very good point to continue diagnosing this. Now, for equality compares of operands of different sign but same precision we could avoid diagnosing those with -Wsign-compare and instead diagnose it elsewhere given obviously mathematically -1u != -1 - it might be a case for -Wconversion? Aka C operand promotion rules change the mathematical meaning?
