I don’t see how those examples are relevant. Why would that last one be faster?

I agree that the OpenBSD code here is good, no more and no less than needed.

I assumed the grandparent was referring to cases where an O(n) algorithm is used where it might be O(log n) or O(1) with just a little more effort. It’s a tradeoff, sure, and in some cases linear searches can work surprisingly well, but in general I think this kind of thing should always be considered in good code.

Micro-optimizations like inline assembly for inner loops may or may not be a good idea, depending on the application. All else being equal, I’d certainly agree that good clean code would not use assembly.

I would expect the openbsd true to be the fastest, it doesn't need to spawn a subshell and it doesn't do more than the posix specification requires (afaik --help/--version should be ignored).