Re: Split `simple.el'?

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Monnier <monnier@IRO.UMontreal.CA>
> Cc: emacs-devel@gnu.org
> Date: Fri, 06 Apr 2018 14:18:10 -0400
> 
> > Actually, this might be more fair:
> >   M-: (length (x-list-fonts "-*-*-normal-*-*-*-13-*-*-*-*-*-iso10646-1")) RET
> > where the "13" part could need a change, if (face-font 'default)
> > reports a different pixel-width of the default font on your system.
> 
> OK, I just tried it on my office's 2006 mac-mini (Core 2 Duo T7600)
> where the above says it has 437 fonts installed (removing the iso10646
> constraint brings it up to 614):

I get 1244 and 1703, respectively, almost 3 times as many.

> So a "normal" start takes ~0.7s and visiting the hello file brings it to
> ~1.5s hence adding less than a second.

I get 0.48s and 10.26s elapsed respectively, with 6s CPU time usage
for visiting HELLO.

> I expect 500 fonts is not considered large, since I'm not particularly
> interested in typography and have installed fairly few fonts above those
> that get installed automatically with a "typical" Gnome desktop.
> 
> But to justify a delay of more than 10s on a non-ancient system, you'd
> need to have at least 10 times as many fonts.  Is that really what's
> going on, or is there something else at play?

I have three time as many fonts, and Emacs on Windows checks 2 font
back-ends before it gives up on characters that don't have any font
supporting them.  The rest is OS differences regarding enumerating
fonts and caching them (or lack thereof) by the font back-end.

As for "ancient", this is a 6 year-old core i7 box.  But I don't think
CPU power is the main cost driver here, because I get the same times
from optimized and non-optimized builds.