[Trilinos-Users] BLAS/LAPACK automatically linked by compiler

[Nico Schlömer]

Hi all,

here's a funny compiler issue.
On NERSC, the BLAS and LAPACK libraries are automatically included on
the link line by their compiler wrappers, much like libmpi.a is
automatically linked on many other platforms.
We've got outselves a little bit of a conflict of responsibilities
here since also CMake tries to care of BLAS and LAPACK, e.g.,

-D TPL_ENABLE_BLAS:BOOL=ON \
      -D BLAS_LIBRARY_DIRS:FILEPATH="$CRAY_LIBSCI_PREFIX_DIR/lib" \
      -D BLAS_LIBRARY_NAMES="sci_gnu" \

The exact library locations aren't officially disclosed, so at best
I'm getting BLAS and LAPACK implicitly twice on the link line. Should
they decide to change their BLAS/LAPACK directories in the wrappers
one day, however, this'll lead to two different BLAS/LAPACK libraries
on the link line which is less than ideal.

What's the situation on other HPCs, and how do you deal with this?

--Nico