charcoal

Unfortunately those SWAR optimizations are only useful for strings that are aligned on 8 bytes address. If your SWAR algorithm is applied on a non-aligned string, it is often slower than the original algorithm. And splitting the algorith in 3 parts (handling the beginning up to an aligned address, then the aligned part, and then the less-than-8-bytes tail) takes even more instructions. Here is a similar case on a false claim of a faster utf8.IsValid in Go, with benchmarks: https://github.com/sugawarayuuta/charcoal/pull/1

A description of the algorithm is here [1] and it is indeed SWAR. [1] https://github.com/sugawarayuuta/charcoal/blob/main/docs/ind...