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- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [eigen] NEON PacketMath.h questions
- From: Gael Guennebaud <gael.guennebaud@xxxxxxxxx>
- Date: Wed, 4 Jul 2012 17:50:05 +0200
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Thank you for the feedback, and thank you Konstantinos for the quick fixes.
Some complements:
On Wed, Jul 4, 2012 at 12:05 AM, Josh Bleecher Snyder
<josharian@xxxxxxxxx> wrote:
> One could also force the use of the vmla instruction via inline
> assembly. This would require distinguishing multiply+add (return a
> value) from multiply+accumulate (modify one of the inputs).
> Multiply+accumulate is extremely common in gemm/gemv and probably
> worth optimizing for. I'm willing to take a crack at adding such a
> method (pmacc? pmadd_inplace? pfma?), although I might need a few
> pointers -- I'm new to both C++ templating and Eigen -- and would
> probably need help with SSE/AltiVec. So before I start on it: Is there
> interest in such an addition?
Don't worry, when we do c = pmadd(a,b,c), then the compiler is smart
enough to recognize that 'c' is on both sides and that we are doing an
accumulation. No need for a specific path here.
> (3)
>
> Is there a good way to run the existing Eigen unit tests on an iOS or
> Android device? (E.g. is there an Xcode-friendly test wrapper? Is
> there interest in one?) I don't have -- or intend to acquire -- a
> beagle board, so testing NEON changes is currently a bit manual and ad
> hoc.
There is clearly a need for a simple way to test Eigen on iOS.
gael