[Debichem-devel] Bug#935993: nwchem: NWChem compiled with long int lapack/blas interface?

[Mo Zhou]

Hi Giacomo and nwchem maintainer,

I should provide you some important hints at this point.

> However, lapack and blas libs with 64 bit integer interfaces just appeared
> on debian experimental, and have been available for some time in the 
> non-free (but packaged in non-free) Intel MKL libs.

I forgot to mention in the changelog of src:lapack that CBLAS64 (the
64bit
indexing C interface) is not yet available, while the rest are fine.
Patching work was planned but currently lacks support from upstream.
Currently libraries that provide CBLAS64 ABI are: libblis64-2,
libmkl-rt.

> export BLAS_SIZE=8
> export BLAS_LIB=-lmkl_blas95_ilp64 -Wl,--start-group -lmkl_gf_ilp64 -lmkl_intel_thread -lmkl_core -Wl,--end-group 
> ...
> export BLASOPT="-lmkl_blas95_ilp64 -lmkl_lapack95_ilp64 -lmkl_scalapack_ilp64 -Wl,--start-group -lmkl_gf_ilp64 > -lmkl_intel_thread -lmkl_core -lmkl_blacs_openmpi_ilp64 -Wl,--end-group -liomp5 -lpthread -lm -ldl"
> export BLACS=$(SCALAPACK)

If nwchem decides to link against MKL, it has to leave the main section.
If nwchem's 64-bit indexing mode doesn't call the CBLAS64 API, you can
go ahead and link the program against src:lapack's libblas64.so and
liblapack64.so . The update-alternatives mechanism will allow you
to switch the backend to MKL at runtime.