On Tue, 24 Oct 2023 at 12:53, Tomas Kalibera <tomas.kalib...@gmail.com> wrote:
>
> The output of session info is based on that flexiblas is used and on
> what flexiblas tells R is the backend it uses. R does not attempt to
> check that optimized LAPACK functions from the backend really end up
> called via flexiblas, and I don't think it could be realistically checked.
>
> But I've checked one case manually in Fedora 38 using Linux perf tool.
> The following code:
>
> S <- toeplitz((10:1)/10)
> repeat { R <- rWishart(10, 20, S) }
>
> uses dpotrf from LAPACK, which is optimized in OpenBLAS and ATLAS and
> the corresponding optimized implementations really appeared on the
> sampling profile for me from the backend libraries.
>
> The comment from R Admin has been removed now and if anyone runs into
> the problem (that an optimized LAPACK function is not called from a
> backend that provides it), it would be best to report it with sufficient
> detail to flexiblas.Thanks, Tomas. Yes, if an expected redirection to an optimized function does not happen, that would be a bug in FlexiBLAS and should be reported upstream. Related to this, a small detail... I noticed that the R configure script reports "BLAS(FlexiBlas)" correctly as an external library, but then "LAPACK(generic)". This should be FlexiBLAS too instead of "generic". It doesn't make any difference, since the LAPACK symbols in FlexiBLAS are called anyway, but it's misleading. Best, -- Iñaki Úcar ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
