[rurban]

As I said there are two best, plus the worse third variant. Not implemented by google, only described, but now apparently implemented in Rust. Haven't checked closely, because Rust is kinda unreadable compared to C what exactly is going on. Need to see the SIMD assembly also. You cannot really trust much what's going on with Rust, as there's too much hype and lies, but it undeniably got better recently.