llvm dev - Dec 2009 - [LLVMdev] Help adding the Bullet physics sdk benchmark to the LLVM test suite?

The linux builds are not using SSE right now, but the vector data is
16-byte aligned on all platforms.
So if you port this SSE code to another platform (Linux, Altivec,
NEON), you could contribute it back to Bullet?
The most interesting SSE part is the innerloop of the constraint
solver: http://tinyurl.com/ydoapct

Some developers replaced some linear algebra functions (in
Bullet/LinearMath) with VFP/Neon
optimizations, but haven't contributed this back.
This NEON/VFP, part of the an open source iPhone project, could be a
starting point for this:
http://tinyurl.com/y9gv3e8

Thanks,
Erwin








2009/12/15 Anton Korobeynikov <anton at
korobeynikov.info>
>
> Hello, Erwin
>
> > Although most of this is plain portable C++ perhaps LLVM can
auto-vectorize
> > some of this?
> Well, I doubt so, unfortunately - LLVM does not have any autopar these days
>
> > There is a little bit of hand optimized x86 SSE code. This is only
enabled
> > on 32bit Windows and Mac OSX Intel builds.
> Ok. What's about Linux builds? Are there any other implementations
> e.g. altivec / NEON ?
>
> > You could take Bullet/Demos/Benchmarks as a starting point, and modify
it so
> > it fits the LLVM test suite?
> Ok, will do.
>
> > What hardware/platforms does the LLVM test suite run on typically?
> So far 32 and 64 bit Linux and MacOS, 32-bit ppc/darwin. Also, there
> is special "small" mode mainly designed for stuff like ARM.
> It will be nice (in theory) to have some NEON/VFP code, since the
> testsuite currently lacks any beanchmark for this.
>
> --
> With best regards, Anton Korobeynikov
> Faculty of Mathematics and Mechanics, Saint Petersburg State University

Hello, Erwin
> So if you port this SSE code to another platform (Linux, Altivec,
> NEON), you could contribute it back to Bullet?
I believe this should work as-is on linux. Am I missing something?
> optimizations, but haven't contributed this back.
> This NEON/VFP, part of the an open source iPhone project, could be a
> starting point for this:
> http://tinyurl.com/y9gv3e8
Ok.

-- 
With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University

It might compile as-is on linux, if is the SIMD syntax is the same, I
haven't tried it.

Has anyone experimented with PS-DSWP to auto-parallelize?
http://liberty.princeton.edu/videos/step-by-step.php

Thanks,
Erwin

By the way, I'm not sure if I mentioned it before, but there are optionals
components
in Bullet that that can benefit from multi threading, using pthreads (or
Win32 threads).
It requires a few minor changes in the benchmark, I can help enabling this.



2009/12/16 Anton Korobeynikov <anton at korobeynikov.info>
> Hello, Erwin
>
> > So if you port this SSE code to another platform (Linux, Altivec,
> > NEON), you could contribute it back to Bullet?
> I believe this should work as-is on linux. Am I missing something?
>
> > optimizations, but haven't contributed this back.
> > This NEON/VFP, part of the an open source iPhone project, could be a
> > starting point for this:
> > http://tinyurl.com/y9gv3e8
> Ok.
>
> --
> With best regards, Anton Korobeynikov
> Faculty of Mathematics and Mechanics, Saint Petersburg State University
>
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On Dec 15, 2009, at 5:15 PM, Erwin Coumans wrote:
> The linux builds are not using SSE right now, but the vector data is
> 16-byte aligned on all platforms.
> So if you port this SSE code to another platform (Linux, Altivec,
> NEON), you could contribute it back to Bullet?
> The most interesting SSE part is the innerloop of the constraint
> solver: http://tinyurl.com/ydoapct
Sounds like a very interesting SSE test.
> 
> Some developers replaced some linear algebra functions (in
> Bullet/LinearMath) with VFP/Neon
> optimizations, but haven't contributed this back.
> This NEON/VFP, part of the an open source iPhone project, could be a
> starting point for this:
> http://tinyurl.com/y9gv3e8
Very unfortunate it's using inline asm. Are there developers should are
interested in using NEON intrinsics?

Evan
> 
> Thanks,
> Erwin
> 
> 
> 
> 
> 
> 
> 
> 
> 2009/12/15 Anton Korobeynikov <anton at korobeynikov.info>
>> 
>> Hello, Erwin
>> 
>>> Although most of this is plain portable C++ perhaps LLVM can
auto-vectorize
>>> some of this?
>> Well, I doubt so, unfortunately - LLVM does not have any autopar these
days
>> 
>>> There is a little bit of hand optimized x86 SSE code. This is only
enabled
>>> on 32bit Windows and Mac OSX Intel builds.
>> Ok. What's about Linux builds? Are there any other implementations
>> e.g. altivec / NEON ?
>> 
>>> You could take Bullet/Demos/Benchmarks as a starting point, and
modify it so
>>> it fits the LLVM test suite?
>> Ok, will do.
>> 
>>> What hardware/platforms does the LLVM test suite run on typically?
>> So far 32 and 64 bit Linux and MacOS, 32-bit ppc/darwin. Also, there
>> is special "small" mode mainly designed for stuff like ARM.
>> It will be nice (in theory) to have some NEON/VFP code, since the
>> testsuite currently lacks any beanchmark for this.
>> 
>> --
>> With best regards, Anton Korobeynikov
>> Faculty of Mathematics and Mechanics, Saint Petersburg State University
> 
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

Hello, Everyone
> Sounds like a very interesting SSE test.
I'm working on it. Hopefully it will be added today or tomorrow to
LLVM testsuite.

-- 
With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University