[Bf-committers] Antw.: 64-bit builds with ray optimization

[Sergey Sharybin]

Ray optimization (which seems to be using sse only) is enabled for linux
too. I still can't see real benefit of using global sse2/sse3 optimization.
Supporting both of optimized and not optimized builds just will took more
time for platform maintainers and will lead to confuse when downloading
archives from blender.org. Think everybody who is really familiar with 3D
graphics already switched to newer 64bit hardware to have more memory
available, and guys who're still using 32bit processors wouldn't really
notice big difference between current builds and builds with global sse2/3
optimization.

On Mon, Dec 12, 2011 at 2:17 PM, Thomas Dinges <blender at dingto.org> wrote:

> I don't like this. We should build our regular builds with all SSE
> extensions we support and make x32 non sse legacy builds. Asking people of
> modern hardware (again, even sse3 is in all cpus from 2005 and later) is
> not the way to go. Big -1!
>
> Sent from my mobile device
>
> ----- Reply message -----
> Von: "Sergey Sharybin" <sergey.vfx at gmail.com>
> An: "bf-blender developers" <bf-committers at blender.org>
> Betreff: [Bf-committers] 64-bit builds with ray optimization
> Datum: Mo., Dez. 12, 2011 08:45
>
>
> Hi,
>
> Tomas, as i understand we're speaking about x86_64 platform, not x86 and
> all x86_64 bit compatible processor are comng with sse2 at least (i'm not
> sure if sse3 is used in out code). It wouldn't be a problem to enable
> rayoptimization and compile with sse/sse2 support (which also improves
> speed of tracking).
>
> Main issue is about x86 platforms. Yes, we've got code which detects if
> sse2 is supported and it's already used in Cycles and blender internal,
> we're only missing such check for motion tracking which is compiling
> without sse2 support on x86 platforms. The here issue is: Eigen library can
> use sse2/sse3 instructions to improve speed of matrix operations, but Eigen
> is totally header-based library and making runtime detection of sse support
> simply wouldn't work here.
>
> So i think we should compile 64bit builds of Blender with rayoptimization,
> sse and sse2 optimizations. For 32bit keep global sse optimizations
> disabled and enable only rayoptimization (it seems to be quite safe).
>
> On Mon, Dec 12, 2011 at 10:59 AM, Thomas Dinges <blender at dingto.org>
> wrote:
>
> > SSE3 was introduced in 2004 by Intel (Pentium 4) and in 2005 by AMD.
> > Thats 6/7 years now already.
> >
> > If there is any code that can't detect SSE2/3 on runtime, we should just
> > make extra builds. But making only 1 build (even for x86) would be
> stupid.
> > It's okay to support 10 year old cpu's who don't have these extensions,
> > but at the same time we should not disable these optimizations for
> > people using, well "old" hardware too. 6/7 years is old. ;-)
> >
> > Am 12.12.2011 02:10, schrieb Antony Riakiotakis:
> > > Hi everyone, it's release time soon.
> > > There has been some debate on irc on the topic of enabling ray
> > > optimization for release builds.
> > >
> > > Pros are: faster program, cons of course are that we are less
> > > compatible with older machines.
> > >
> > > I see though no reason why 64-bit machines, that support sse2, should
> > > not be built with ray optimization on by default.
> > >
> > > If this is decided upon, there are some -sse3 flags in cycles that
> > > should probably be taken care of.
> > > _______________________________________________
> > > Bf-committers mailing list
> > > Bf-committers at blender.org
> > > http://lists.blender.org/mailman/listinfo/bf-committers
> >
> >
> > --
> > Thomas Dinges
> > Blender Developer, Artist and Musician
> >
> > www.dingto.org
> >
> > _______________________________________________
> > Bf-committers mailing list
> > Bf-committers at blender.org
> > http://lists.blender.org/mailman/listinfo/bf-committers
> >
>
>
>
> --
> With best regards, Sergey Sharybin
> _______________________________________________
> Bf-committers mailing list
> Bf-committers at blender.org
> http://lists.blender.org/mailman/listinfo/bf-committers
> _______________________________________________
> Bf-committers mailing list
> Bf-committers at blender.org
> http://lists.blender.org/mailman/listinfo/bf-committers
>



-- 
With best regards, Sergey Sharybin