Re: Emacs using SSE2 on x86

[Andrea Corallo]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Sven Joachim <svenjoac@gmx.de>
>> Date: Sat, 04 Jul 2020 20:58:34 +0200
>> Cc: Emacs Development <Emacs-devel@gnu.org>
>> 
>> The Debian i386 port still uses older machines without SSE2 as its
>> baseline, and apparently there are some people who still use Pentium III
>> or Athlon XP machines, even for web browsing[1].
>> 
>> Whether you want to support them is up to you, but in general Emacs runs
>> very well even on such old hardware.
>
> Maybe we should step back a notch and remind ourselves why do we want
> to make this change.  What exactly are we going to gain, and are these
> gains important enough for us to have to deal with all the issues it
> will raise (some of which were already mentioned in this discussion)?

Is the only concern the moving in the compile-time of floating point
operations those result is not completely portable while producing the
.elc?  If this is the case I'm wondering how many of these optimizations
do we really perform compiling Emacs and if we really care about the
possible rounding difference.

If this is the case, regarding the first question, should easy to just
count performing a bootstrap with some instrumentation.

Regards

  Andrea

-- 
akrl@sdf.org