bug#65250: 30.0.50; "C-h f" is much slower on the master branch

[Eli Zaretskii]

> From: Andrea Corallo <acorallo@gnu.org>
> Cc: 65250@debbugs.gnu.org
> Date: Sat, 12 Aug 2023 12:57:27 -0400
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > To reproduce:
> >
> >   emacs -Q
> >   C-h f dictionary-search RET
> >
> > (almost any other function will do, I think).
> >
> > This takes a whopping 6.6 sec of CPU on master, vs 2.4 sec on the
> > emacs-29 branch.  These are both unoptimized builds, but even so,
> > 6.6 seconds of CPU time for looking up a doc string of a function
> > is too much, I think.
> >
> > The patch below fixes the problem in a build without
> > native-compilation, but won't help in a build with native-compilation.
> > I wonder why comp-function-type-spec is so expensive?
> 
> Hi Eli,
> 
> can't look at this now, will do on Monday and report.

Thanks, this is on master, so not very urgent.