Re: autovectorize page checksum code included elsewhere

On Tue, Nov 7, 2023 at 9:47 AM Nathan Bossart <nathandbossart@gmail.com> wrote:
>
> Presently, we ask compilers to autovectorize checksum.c and numeric.c.  The
> page checksum code actually lives in checksum_impl.h, and checksum.c just
> includes it.  But checksum_impl.h is also used in pg_upgrade/file.c and
> pg_checksums.c, and since we don't ask compilers to autovectorize those
> files, the page checksum code may remain un-vectorized.

Poking in those files a bit, I also see references to building with
SSE 4.1. Maybe that's an avenue that we should pursue? (an indirect
function call is surely worth it for page-sized data)