Re: [boost] [gsoc18][ublas] Proposal to add advanced matrix operations

Subject: Re: [boost] [gsoc18][ublas] Proposal to add advanced matrix operations
From: Marcin Copik (mcopik_at_[hidden])
Date: 2018-01-26 09:52:32

wt., 23 sty 2018 o 14:52 użytkownik Hans Dembinski <hans.dembinski_at_[hidden]>
napisał:

> On 22. Jan 2018, at 22:50, Marcin Copik via Boost <boost_at_[hidden]>
> wrote:
>
>
> I've done a lot of linear algebra benchmarking in the last couple of months
> and I believe there are three high-performance C++ linear algebra
> libraries: Eigen, already mentioned by Hans, Armadillo, and Blaze. Blaze
> developers present several benchmarks on their website:
> https://bitbucket.org/blaze-lib/blaze/wiki/Benchmarks
>
>
> It looks like whoever makes the benchmarks wins ;)
>
> Since Eigen3 does much worse in these benchmarks, I wonder whether the
> comparison is fair. I cannot imagine a good reason why Eigen is much faster
> than uBlas in their own benchmarks and much slower than uBlas in the
> benchmarks shown by Blaze.
>

I'm surprised why Eigen performs so poorly with BLAS-1 functionalities.
Blaze benchmarks are in the repository and I can't see an easy answer how
the timing could be skewed against Eigen:
https://bitbucket.org/blaze-lib/blaze/src/ed0d6f15559e6019d1b10d7010b753182ab90f09/blazemark/src/eigen/DVecDVecAdd.cpp
To me it looks like a vectorization which does not utilize AVX capabilities.

>
> Best regards,
> Hans
>