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

[Eli Zaretskii]

> From: Paul Eggert <address@hidden>
> Date: Tue, 3 Jul 2018 23:36:44 -0700
> Cc: address@hidden, address@hidden
> 
> For rarely_quit, with -O2 typically the overhead 
> of the rarely_quit call (including computing its argument) is typically just 
> two 
> CPU instructions (a test and a conditional branch that is predicted 
> correctly, 
> so both instructions are cheap). This is way better than -O0.

It's not rarely_quit that is expensive, it's the few calls to
maybe_quit it does, because maybe_quit accesses two Lisp symbols.  I
think.