Fwd: Problems switching BLAS and LAPACK versions

[Tommi Höynälänmaa]

---------- Forwarded message ----------
From: Tommi Höynälänmaa <address@hidden>
Date: 2017-01-17 17:21 GMT+02:00
Subject: Re: Problems switching BLAS and LAPACK versions
To: Mike Miller <address@hidden>

I built liboctave debian packages myself with some minor changes. Liboctave is linked with -lblas and I have both libblas and atlas installed but libblas is active. I don't have openblas. I tried to set a breakpoint to dnrm2_ but gdb can't debug inside libblas even though I compiled it with debug information and gdb is able to load the symbol information. When I looked at the assembly code of dnrm2 it seemed that the debug write command I added to dnrm2 in blas is present.

     - Tommi

2016-12-26 19:59 GMT+02:00 Mike Miller <address@hidden>:

On Mon, Dec 26, 2016 at 13:57:34 +0200, Tommi Höynälänmaa wrote:
> I have problems with switching BLAS libraries with
> update-alternatives. I have built my own Debian packages of BLAS where
> I added some debug write commands to dnrm2.f. Then I switched the
> system to use my own version of BLAS with command "update-alternatives
> --config libblas.so.3". When I use liboctave Matrix::lssolve and link
> my program to BLAS I see no debug outputs and apparently my own
> version of dnrm2 is not called.
>
> What is wrong here?

That may depend on how you installed Octave. Is Octave installed from
Debian archive packages or did you build it from source yourself? Is
liboctave linked against libblas or libopenblas? If you set a breakpoint
on dnrm2_ in gdb, does it reveal more about which library is being
called?

--
mike