Right now I do run-time switching between the legacy and the gemm-based implementation based on the matrix size.

This incurs a slight overhead because of the extra branch, but this is the best tradeoff I was able to come up.

I'd rather avoid introducing a new function for multiplying matrices, as there are already five ways to do that in ublas. So it is already way more confusing than it should be.

I could change the branch to a compile-time one for matrix types where compile-time size information is available, but I am unsure of how widely those matrix types are used. (I've never seen anybody using anything else than vanilla matrix.) If you (or anybody) would be interested in such a feature, then please let me know.

 On Monday, 7
                  March 2016, 17:56, Riccardo Rossi
                  <rrossi@cimne.upc.edu> wrote:

Hi,

                          just to give my two cents, some care shall be
                          taken so that there is no overhead for very
                          small matrices (say 3*3)

                        cheers

                      Riccardo

On Sun, Mar
                        6, 2016 at 9:58 PM, palik imre <imre_palik@yahoo.co.uk>
                        wrote:

                        It just ocured to me, that based on
                                  the descriptor struct it would be
                                  possible to choose between parallel
                                  and serial implementation of the
                                  kernels.

Anybody would be interested in
                                  having something like that in ublas?

Would an OpenMP parallel
                                  implementation be accepted to the
                                  library?

Thanks,

Imre
 
 On Sunday, 6 March
                                          2016, 10:43, palik imre <imre_palik@yahoo.co.uk>
                                          wrote:

Fork is here: https://github.com/imre-palik/ublas/tree/feature/ublas00004_simd_gemm

                                        pull request is sent.

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                      -- 
Riccardo
                                  Rossi

                                PhD, Civil Engineer

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                                of the Kratos Team: www.cimne.com/kratos

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                                  at Universitat Politècnica de
                                  Catalunya, BarcelonaTech (UPC)

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                                Numerical Methods in Engineering (CIMNE)

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