Re: Emacs pretest -- electric-pair-mode change

[Eli Zaretskii <eliz@gnu.org>]

> From: joaotavora@gmail.com (João Távora)
> Date: Thu, 03 Apr 2014 21:11:49 +0100
> Cc: emacs-devel@gnu.org
> 
> Stefan Monnier <monnier@IRO.UMontreal.CA> writes:
> 
> >>> [ Unrelated: it's odd that the speed should depend on the OS.  ]
> >> I'm using two relatively similar dual-core machines. In windows I use
> > Ah, so the difference is in the way they're compiled.
> 
> Of course, scheduling aside, in the end that's always true :-).

Scheduling is not really relevant here, since Emacs has only one
thread that runs Lisp, and its other threads, if there are any, don't
run any computation-intensive tasks that could yield user-visible
speed differences.

> I might have misunderstood Eli Zaretskii's:
> 
>    http://lists.gnu.org/archive/html/emacs-devel/2014-03/msg00930.html

That just describes how Windows binaries are compiled, but says
nothing about their speed relative to other systems.

> But in general, is the machine-code for windows builds exactly the same
> (or very similar) as linux for things involved in these operations?

It's the same compiler (GCC) and similar or identical machine
architectures, so I don't expect very different code.  Optimizations
change things, of course, but only by a factor of about 2.  Any
greater speed difference is due to something else.

> If so, how can I check the compile flags of a build?

"M-: system-configuration-options RET"

> Because mine really is slower. My OSX build is also much slower,
> FWIW, not as slow as windows tho.

Again, if the slow-down is more than twice, it's not the compiler
switches.  You should also compare the CPU speed for a single core.
Or just rebuild the same code with different optimizations and see if
you get the slower/faster speed.