On 2024-Jan-25, Alvaro Herrera wrote:
> Finally, the matter of using ifunc as proposed by Noah seems to be still
> in the air, with no patches offered for the popcount family.
Oh, I just realized that the patch as currently proposed is placing the
optimized popcount code in the path that does not require going through
a function pointer. So the performance increase is probably coming from
both avoiding jumping through the pointer as well as from the improved
instruction.
This suggests that finding a way to make the ifunc stuff work (with good
performance) is critical to this work.
--
Álvaro Herrera Breisgau, Deutschland — https://www.EnterpriseDB.com/
"The ability of users to misuse tools is, of course, legendary" (David Steele)
https://postgr.es/m/11b38a96-6ded-4668-b772-40f992132797@pgmasters.net