On: Show HN: Charcoal – Faster utf8.Valid using multi-...

[WASDx]

What is the gist of the algorithm? I'm not proficient at reading Go. Is it perhaps doing https://en.wikipedia.org/wiki/SWAR which is indeed SIMD?

[danbruc → WASDx]

A description of the algorithm is here [1] and it is indeed SWAR.

[1] https://github.com/sugawarayuuta/charcoal/blob/main/docs/ind...

[syrak → danbruc]

This post is rendered at https://sugawarayuuta.github.io/charcoal/

[kevincox → WASDx]

Yes. The algorithm is very much using SIMD in the abstract sense but it isn't using SIMD instructions.

It is basically using 64 bit integer operations to check 8 bytes at a time.