| Re: [eigen] FLENS C++ expression template Library has excellent documentation |
[ Thread Index |
Date Index
| More lists.tuxfamily.org/eigen Archives
]
- 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
- Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=pjKGgZjrPTk6S1jgM62yN0aB3rwTZlt4me6NkRBMo6c=; b=AtlcQ3TB2MLn5chbazdNc5mz5vooZtLg76NVj4T1kUUx+8OJu1mdjIwJdWmQNRLljj 37Qc/xjSWBjRAlF48Uoz2g+U7BHNgbAtGJAa/tmDtVoPFo40mZIkiQoTGZvP2d4zQRc9 lhRU27gmbJviikvsa+fnbmolLFObqbh7rUfCc=
- Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=aOzjthHnh2jx5Ivdbxo5XoQU5/pTYiD0oO/UtVkE/beB8aivjMEArnlvaDFflKTb7/ 3wZTk67QZRS86GWEg6uF1YVK7oi5KnLBcJrhs+F2b5EM1qhbMojfmtyqMJioTLyYgYzk s5uHsjx2MYI0uJxVpIzw+yH0Zr2G7/T1LboVY=
> 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?
-Ilya