Re: A qsort template

On Wed, 13 Apr 2022 at 23:19, John Naylor <john(dot)naylor(at)enterprisedb(dot)com> wrote:
> More broadly than the regression, Thomas' is very often the fastest of
> all, at the cost of more binary size. David's is occasionally slower
> than v15 or v15 with revert, but much of that is a slight difference
> and some is probably noise.

Just to get an opinion from some other hardware, I've run your test
script on my AMD 3990x machine.

My opinion here is that the best thing we can learn from both of our
results is, do the patches fix the regression?

I don't believe it should be about if adding the additional
specializations performs better than skipping the tie break function
call. I think it's pretty obvious that the specializations will be
faster. I think if it was decided that v16 would be the version where
more work should be done to decide on what should be specialized and
what shouldn't be, then we shouldn't let this regression force our
hand to make that choice now. It'll be pretty hard to remove any
specializations once they've been in a released version of Postgres.

David