[Rd] openblas

[Iñaki Ucar]

On Wed, 8 May 2019 at 18:00, Ralf Stubner <ralf.stubner using daqana.com> wrote:
>
> On 08.05.19 09:34, Iñaki Ucar wrote:
> > On Wed, 8 May 2019 at 04:52, Peter Langfelder
> > <peter.langfelder using gmail.com> wrote:
> >>
> >> (CCing the R-devel list, maybe someone will have a better answer.)
> >>
> >> To be honest, I don't know how to. I wasn't able to configure R to use
> >> OpenBLAS using the configure script and options on my Linux Fedora system.
> >> I configure it without external BLAS, then replace the libRblas.dylib (.so
> >> in my case) with a link to the OpenBLAS dynamic link library.
> >
> > R on Fedora uses openblas by default since Fedora 23. In fact, there's
> > a specific package, openblas-Rblas, that provides libRblas.so.
>
> AFAIK a single-threaded OpenBLAS is used.

Of course it is the serial version. It wouldn't be a good policy to
ship a threaded shared library by default.

> When compiling R from source
> on a CentOS system I have used the configure option
> '--with-blas="-lopenblasp"' to link with the pthread version of OpenBLAS.

CentOS uses the reference BLAS by default instead. It's a long story.
But both CentOS and Fedora configure R with --enable-BLAS-shlib, so
you don't need to recompile it to use an optimized version.

Iñaki