Re: CRC32C Parallel Computation Optimization on ARM

On Wed, Mar 12, 2025 at 01:51:08PM +0700, John Naylor wrote:
> On Wed, Mar 12, 2025 at 12:46 AM Devulapalli, Raghuveer
> <raghuveer(dot)devulapalli(at)intel(dot)com> wrote:
> >
> > I am happy to submit a patch with a C fallback version that leverages the specific algorithm/technique mentioned in the white paper to make it clear that Intel has contributed this specific technique to Postgres under Postgres license terms. That should hopefully address any lingering concerns anyone may have w.r.t using this technique for the benefit of Postgres.
>
> Thanks for offering, but I'm unclear if that's actually necessary. I'm
> still confused as to what the status of the patents are. From your
> last response:
>
> > Intel has contributed SSE4.2 CRC32C [1] and AVX-512 CRC32C [2] based on similar techniques to postgres.
>
> ...this is a restatement of facts we already know. I'm guessing the
> intended takeaway is "since Intel submitted an implementation to us
> based on paper A, then we are free to separately also use a technique
> from paper B (which cites patents)". I'd be delighted to hear that, if
> that's what you found from talking to a legal team, but it's not clear
> to me.

Contributing code is copyright, which is unrelated to patents. I don't
think the Postgres community even has a method of accepting patent usage
grants.

--
Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com

Do not let urgent matters crowd out time for investment in the future.