> I've added a pointless strlen(). It seems like no compiler is clever enough to remove it.
For that you could at least argue that if the libc's strlen is faster than strcmp, that improves performance if the programmer expects the function to be usually called with a short input.
That said, changing it to `if (strlen(s) == 5) return 0;` it still doesn't get optimized (https://godbolt.org/z/7feWWjhfo), even though the entire function is completely equivalent to just `return 0;`.
For that you could at least argue that if the libc's strlen is faster than strcmp, that improves performance if the programmer expects the function to be usually called with a short input.
That said, changing it to `if (strlen(s) == 5) return 0;` it still doesn't get optimized (https://godbolt.org/z/7feWWjhfo), even though the entire function is completely equivalent to just `return 0;`.