|Re: [eigen] NEON PacketMath.h questions|
[ Thread Index |
| More lists.tuxfamily.org/eigen Archives
- 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
- Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type; bh=S7BU24smMRCy5T+9xvbqu3iJzDOrclENBkRJfpH5j7U=; b=Ot9U9Npc7Ofx3NJQo7pHgqeetRwXwR374Yab6lzBXEE2dZnU60NeOuKAQFnZzwLcoB yOr43+zgjmb1eZzr8/unOiyBM+MNKeH9uOPZqvEnRTJCFyDAu+2oScwP67G1hApq7BeD 6/qDW1xsuTTSIwhjLJuvvmrInfRsia7Gdt+EdDfzQ5mWWAqobrGyII5PXaocAeYVB0hB Gg2MWn7sgbv/P/boTdsv4VoN1d/l8Ruit/ggeNULe+XFHJSHfZLXTJ+LEmX5ioh4nGy4 V5A8YicaNBFKStaGLJ1Smtz/4BmJCjKfnYSNt2iQ5Kk/YQMCvhXKKKvo4yfjSDOM1kBg zZmw==
Thank you for the feedback, and thank you Konstantinos for the quick fixes.
On Wed, Jul 4, 2012 at 12:05 AM, Josh Bleecher Snyder
> 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.
> 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
There is clearly a need for a simple way to test Eigen on iOS.