Re: bug-reference-prog-mode slows down CC Mode's scrolling by ~7%

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: acm@muc.de,  emacs-devel@gnu.org
> Date: Sun, 12 Sep 2021 13:41:05 -0400
> 
> > Yes, of course.  Which is why I think that having the entire code
> > hidden is a rare phenomenon, even in your sessions.  Because once you
> > visit a file, you usually reveal the code, in order to work on it.
> 
> Right, but the big gain is right when I open the file, where jit-lock
> only fontifies a handful of chunks even though often both point-min and
> point-max are visible.

I think the gain is illusory, because as soon as you unhide the code,
we start fontifying everything as usual.  IOW, hiding text is for this
purpose the same as simply leaving it off-screen.