Graham Sutherland / Polynomial's Post

@dysfun there's probably some fancy shit you can do with it (I'd bet there's cleverness you can do with things like upper/lower parity, alternating bit parity, etc. for further bit re-ordering shenanigans) but I've got a pretty hefty knowledge gap there.

ultimately if you can express existing bit twiddle tricks as matrix multiplications mod 2 with an optional xor on the end, then it'll do the job in a single instruction. it just happens to reduce to a parity calc due to the vector product step.