[Distutils] warning about potential problem for wheels

[Chris Barker]

On Wed, Oct 14, 2015 at 3:40 AM, Antoine Pitrou <solipsis at pitrou.net> wrote:

> On Tue, 13 Oct 2015 09:59:05 -0700
> Chris Barker <chris.barker at noaa.gov> wrote:
> >
> > So even is SSE2 provides little for Python itself, in the usual case,
> we'll
> > see performance hits n compiled extensions that are not compiled by
> > particularly smart people.
>
> Since the question is only for 32-bit builds,


IS that the case:
"""
Note that my recently retired computer was 64 bit and had SSE but didn't
have SSE2 (I'm fairly sure - CPU was some budget AMD model)
"""

granted, such machines are probably really really rare, but maybe it does
matter for 64 bit, too?


> does this even matter?
> 32-bit builds on x86 generally bring you poorer performance by
> themselves,


If a user has a 32 bit machine, they have no choice -- we could argue that
anyone for whom performance matters probably isn't running an old, cheap
machine, but still...


>  If you want better performance (or want
> to efficiently address 3+GB of RAM, which is an extremely common
> situation nowadays), you probably want 64-bit builds.
>

I thought that wasn't the case (well it certainly is if you want to access
that memory), but for raw performance, 64 bit is pushing a lot more memory,
in the form of larger pointers, around -- so is sometimes slower. I'm sure
it depends on the use-case, as it always does....

Also a note -- I'm lost on the details, but the most recent numpy release
required SSE2:

"""
* Compiling with msvc9 or msvc10 for 32 bit Windows now requires SSE2.
  This was the easiest fix for what looked to be some miscompiled code when
  SSE2 was not used. If you need to compile for 32 bit Windows systems
  without SSE2 support, mingw32 should still work.
"""

and that's not py3.5 (msvc9 is the py2.7 compiler, and msvc10 is py3.4,
yes???)

-Chris











>
> Regards
>
> Antoine.
> _______________________________________________
> Distutils-SIG maillist  -  Distutils-SIG at python.org
> https://mail.python.org/mailman/listinfo/distutils-sig
>



-- 

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