[tptacek]

Just for what it's worth, we're talking about the amd64 assembly version of the SHA3 code in the x/crypto/sha3 library; I didn't look carefully at how it's called, so if it's used incrementally the way this Go code shows, then yeah, it's fine regardless.

A second later

Oh, wait, yeah, this is just the Keccak permutation in assembly, not the entire hash. That was dumb of me. Yeah, this code looks ok?

[halffullbrain]

Indeed, the two assembly variants are just of the 1600 byte block bit fiddling (keccakF1600).

The outer loop of the Write method (function?) is the same for all architectures.