[atlas-devel] 3.9.21

[<wh...@cs...>]

Guys,

I have finally released 3.9.21.  The main new feature is that ATLAS
now probes for the number of threads to use by problem size.  On the
platforms I've tested so far, it doesn't have a huge effect on
performance, except for some limited small problem sizes (eg., an
N=200 QR got 47% faster for my 8-core system, but an N=300 wasn't noticably
faster).

Originally, I had hand-tuned crossover points.  I hand-tuned these
crossovers for the exact machines I used the new auto-tuning system
for.  The hope is that for other systems, the performance improvements
will be greater.  

I will also undoubtedly need to extend this autotuner further, including
trying to find additional ways to speed it up (right now it can add an
hour to an install if you don't have arch defs).

Let me know if you see noticable speedup or slowdown from 3.9.20
Changelog is below.

Cheers,
Clint

ATLAS 3.9.21 released 01/11/10, changes from 3.9.20
   * Fixed error in threaded SYMM, where recursion had bad pointer
   * Created ability to tune threaded/serial crossover points, see
        ATLAS/tune/blas/gemm/txover.c
   * Improved CacheEdge detection
   * Fixed bug in configure for --shared on archs w/o f77 compiler
   * Updated lanbtst to work wt new QR naming scheme, and to compile
     correctly for lanbtime (was not using lapack's ILAENV in this case)

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