Re: CRC32C Parallel Computation Optimization on ARM

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.

The original proposal that started this thread is below, and I'd like
to give that author credit for initiating that work, as long as there
is no legal issue with that:

https://www.postgresql.org/message-id/DB9PR08MB6991329A73923BF8ED4B3422F5DBA@DB9PR08MB6991.eurprd08.prod.outlook.com

--
John Naylor
Amazon Web Services