[atlas-devel] results from tuning LAPACK

[Clint W. <wh...@pa...>]

Guys,

My paper on the benefits of empirically tuning LAPACK's ILAENV-controlled NB
has been accepted for CANA'08.  You can see a draft of it at:
   http://www.cs.utsa.edu/~whaley/papers/lanb.pdf

It shows the advantage you get from tuning NB for several different BLAS
an a couple of platforms.  Depending on problem size and architecture,
you can be leaving as much as 30% (or 75%, if on the Itanium :) on the table
if you use stock lapack's ILAENV.  It also highlights two new tools available
in ATLAS (lapack timer/tuner and a tool that takes ATLAS timer output,
does some simple statistics, and prints it out in a spreadsheet friendly
format).

We can apply this tuning to pretty much any blocked LAPACK routine.  ATLAS
presently handles tuning the factorizations.  My guess is that the next
most important routines are the eigencodes.  Does anyone want to nominate
particular routines that they use a lot?

Cheers,
Clint

**************************************************************************
** R. Clint Whaley, PhD ** Assist Prof, UTSA ** www.cs.utsa.edu/~whaley **
**************************************************************************