[nigeltao]

Here's another SIMD implementation, with commentary: https://github.com/google/wuffs/blob/main/std/adler32/common...

Like the fpng implementation, it's SSE (128-bit registers), but the inner loop eats 32 bytes at a time, not 16.

"Wuffs’ Adler-32 implementation is around 6.4x faster (11.3GB/s vs 1.76GB/s) than the one from zlib-the-library", which IIUC is roughly comparable to the article's defer32. https://nigeltao.github.io/blog/2021/fastest-safest-png-deco...