Hello,
That is necessary because most people consume PostgreSQL through
packages from distributions that have to work on an Athlon II or
whatever, so we can't just use -msse4.2 for every translation unit.
So it becomes our job to isolate small bits of code that use newer
instructions, if it's really worth the effort to do that, and supply
our own runtime checks and provide a fallback.
Ok. That was my understanding so as to improve the portability/performance
compromise. I do not think that pgbench is worth the effort on this
particular point.
[...] None of that seems worth it for something like this.
Indeed.
So, am I right to deducing that you are satisfied with the current status
of the patch, with the nbits implementation either based on popcount (v4)
or clz (v5) compiler intrinsics? I think that the clz option is better.
--
Fabien.
