On 15/01/2026 18:08, Nathan Bossart wrote:
On Thu, Jan 15, 2026 at 11:42:14AM +0200, Heikki Linnakangas wrote:
Yeah, I noticed that on x86_64, pg_popcount_optimized is always a function
pointer with runtime check, even if you use compiler flags to target a CPU
where the special instructions are available unconditionally.
I wonder how close we are to being able to just require SSE4.2/POPCNT for
x86-64 builds. I suppose there's always a chance that someone will try to
run Postgres 19 on a CPU from the aughts... In any case, avoiding the
function pointer when possible seems like a good follow-up.
It's not really our decision. Packagers choose which architecture to
target and which compiler options to build with. We ought to just
respect those choices.
- Heikki
