Re: Popcount optimization using AVX512 - Mailing list pgsql-hackers

On Wed, Jul 31, 2024 at 12:50 PM Andres Freund <andres@anarazel.de> wrote:
> It's one thing for the avx512 path to have that overhead, but it's
> particularly absurd for pg_popcount32/pg_popcount64, where
>
> a) The function call overhead is a larger proportion of the cost.
> b) the instruction is almost universally available, including in the
>    architecture baseline x86-64-v2, which several distros are using as the
>    x86-64 baseline.

FWIW, another recent thread about that:

https://www.postgresql.org/message-id/flat/CA%2BhUKGKS64zJezV9y9mPcB-J0i%2BfLGiv3FAdwSH_3SCaVdrjyQ%40mail.gmail.com