[IPOL discuss] [LATE] Re: Clapack and cblas libraries interfacing

[Nicolas Limare]

Hi,

For those interested, I spend a couple of more hours on this
matter. The result, rewritten and hopefully easier to understand, is
there:
http://limare.perso.math.cnrs.fr/notes/2014/10/31_cblas_clapack_lapacke/

For IPOL, the guidelines should be changed to:
1. for BLAS, use the CBLAS C interface
2. for LAPACK, use the LAPACK Fortran interface for gcc/gfortran
Once the IPOL server is upgraded and liblapacke instaled, it can become:
1. for BLAS, use the CBLAS C interface
2. for LAPACK, use the LAPACKE C interface
I will suggest a phrasing for these changes.

For CBLAS on your development machines, you can use these libraries

CBLAS     BLAS
--------  --------
MKL       MKL
OpenBLAS  OpenBLAS
ATLAS     ATLAS
GSL       -
Netlib    Netlib

For LAPACKE, I think the following stacks are possible with the proper
link option:

LAPACKE   LAPACK    BLAS
--------  --------  --------
MKL       MKL       MKL
Netlib    OpenBLAS  OpenBLAS
Netlib    OpenBLAS  ATLAS
Netlib    Netlib    ATLAS
Netlib    Netlib    Netlib
       
On recent multi-core with AVX vector extensions, MKL is
faster. Otherwise, if your code depends on linear algebra, it's worth
trying to find the best option.

All the best,

-- 
Nicolas LIMARE
http://nicolas.limare.net/                         pgp:0xFA423F4F
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 181 bytes
Desc: Digital signature
URL: <https://tools.ipol.im/mailman/archive/discuss/attachments/20141031/14da761e/attachment.pgp>