Re: matrix library ?

From: boost_at_[hidden]
Date: 2001-03-26 14:57:00

Salut

[...]
--- In boost_at_y..., lums_at_l... wrote:
> --- In boost_at_y..., boost_at_s... wrote:
> > the left, and B_i appears on the right. 
> > So using different storage layouts, I can increase performance
> > since no strides appear.
> 
> For dense time dense the storage layout of the original matrices 
is 
> somewhat irrelevant for performance issues.  By performing 
> appropriate blocking and re-arranging for optimal layout within 
the 
> working blocks, one can get optimal performance for any original 
> layout.  ATLAS, PhiPAC, optimized BLAS, and MTL all do this AFAIK.
> 
> That is, yes, layout is important, but only in the working blocks. 
 
> Any original storage format can be copied to a good orientation in 
> the working blocks within the mat-mult algorithm.

O.k., I never written blocked versions of matmuls, so I assume
you're right.

Nevertheless one should provide both memory layouts, allthough
one may name it differently, for representing transposed matrices.

Best wishes,
Peter
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