Re: emacs-26 eec71eb: Speed up replace-buffer-contents

[Eli Zaretskii <eliz@gnu.org>]

> Date: Wed, 04 Jul 2018 21:40:22 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: rgm@gnu.org, emacs-devel@gnu.org
> 
> > Cc: rgm@gnu.org, emacs-devel@gnu.org
> > From: Paul Eggert <eggert@cs.ucla.edu>
> > Date: Wed, 4 Jul 2018 11:30:12 -0700
> > 
> > If that's the case, there's still a performance bug in there. The point of 
> > rarely_quit is to avoid calling maybe_quit in the vast majority of cases. If 
> > maybe_quit is being called so often that it's a performance hog, then it's being 
> > called too often.
> 
> Maybe I'm mistaken, then.  I will see what an optimized build shows.

Profiling the optimized build shows that 60% of the time is spent
inside buffer_chars_equal, and another 26% inside compareseq.
rarely_quit and maybe_quit are nowhere in sight in the profile.

And on my machine, the original recipe of bug#31888 completes in 2.5
sec of CPU time in the optimized build, which is "fast enough", IMO.

So I think we have no performance problem we need to fix, right?