> Compilers like XLC will actually even assume unsigned loop induction variables will not ovefrlow at O3
That's not exactly fair. The C standard guarantees that unsigned variables will overflow by wrapping, so if the compiler assumes such a loop won't terminate, it is not conformant.
That's not exactly fair. The C standard guarantees that unsigned variables will overflow by wrapping, so if the compiler assumes such a loop won't terminate, it is not conformant.