|Re: [eigen] FLENS C++ expression template Library has excellent documentation|
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- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [eigen] FLENS C++ expression template Library has excellent documentation
- From: Ilya Baran <baran37@xxxxxxxxx>
- Date: Sat, 18 Apr 2009 16:33:13 -0400
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> On Sat, Apr 18, 2009 at 6:06 PM, Benoit Jacob <jacob.benoit.1@xxxxxxxxx> wrote:
>> I really mean to implement Block LLt or partial LU soon, it can be
>> written cleanly with Eigen blocks.
> Actually, I've already tried a block LLt implementation (so using BLAS
> 3 routines) and it was slower than our current level 2 based
> implementation. so... I wish you good luck as it seems not to be so
> trivial to get higher performance !
All three variants from FLAME use syrk (A^T * A) which is currently
half as fast in Eigen as it could be. Could that explain the
performance penalty or did you use another blocked method?