On 2019-Feb-15, Tom Lane wrote:
> Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> > I'm done with this stuff. Anybody feel free to run with it, but for a
> > barely noticeable performance improvement it's not going to be me.
>
> Sure, I'll pick it up. I agree it's probably a marginal performance
> change, but it seems a shame to give up when we were 80% of the way
> there.
(BTW, my reading of the articles I cited, as well as my own runs of the
test programs therein, suggest that in order to get a really good
performance improvement you need to hand-code calls to the POPCNT
instruction in assembly rather than rely on the compiler intrinsics. I
think there is^Wwas almost enough infrastructure to do that. I'm not
sure that the operations being optimized by these changes are
interesting enough, in the grand scheme of things.)
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
