RE: Popcount optimization using AVX512

> -----Original Message-----
> From: Nathan Bossart <nathandbossart@gmail.com>
> Sent: Monday, March 18, 2024 9:20 AM
> ...
> I don't think David was suggesting that we need to remove the runtime checks
> for AVX512.  IIUC he was pointing out that most of the performance gain is
> from removing the function call overhead, which your v8-0002 patch already
> does for the proposed AVX512 code.  We can apply a similar optimization for
> systems without AVX512 by inlining the code for
> pg_popcount64() and pg_popcount32().

Ok, got you.

Question: I applied the patch for the drive_popcount* functions and rebuilt.  The resultant server complains that the
functionis missing. What is the trick to make this work? 

Another Question: Is there a reason "time psql" is used over the Postgres "\timing" command?

Thanks,
Paul