[gmx-developers] instructions for mpicc+ESSL on Blue Gene

[Jeff Hammond]

admin/installguide/installguide.tex states "mpicc is used for
compiling and linking. This can make it awkward to attempt to use
IBM's optimized BLAS/LAPACK called ESSL."

I use ESSL with GCC-based compilers all the time on Blue Gene.  The
following is an excerpt from a build system file that indicates how to
include the XL runtime libraries.

export MATHLIBS="-L/soft/libraries/alcf/current/xl/LAPACK/lib/ -lapack
-L/soft/libraries/alcf/current/xl/BLAS/lib/ -lblas
/soft/libraries/essl/current/essl/5.1/lib64/libesslsmpbg.a"
export XLLIBS="-L${IBM_MAIN_DIR}/xlf/bg/14.1/bglib64
-L${IBM_MAIN_DIR}/xlsmp/bg/3.1/bglib64 -lxlf90_r -lxlsmp -lxlfmath
-lxl -lrt -ldl"
export LIBS="${MATHLIBS} ${XLLIBS} -Wl,--allow-multiple-definition"

If one is not using ALCF, the /soft/libraries/alcf/... paths can be
replaced with the appropriate pointers to Netlib LAPACK and BLAS,
which are required for some codes that use LAPACK functions that are
not provided by ESSL.  If Gromacs doesn't need those functions, the
paths and associated libraries can be omitted.

The IBM_MAIN_DIR variable should be set automatically if the XL
compilers are configured properly.  If that variable is not defined,
it should be set manually to the directory containing the following:

$ ll $IBM_MAIN_DIR
total 0
drwxr-xr-x 3 root root 512 Feb 13 17:54 lib
drwxr-xr-x 3 root root 512 Feb 13 17:54 lib64
drwxr-xr-x 3 root root 512 Feb 13 17:54 msg
drwxr-xr-x 3 root root 512 Feb 13 17:54 vac
drwxr-xr-x 3 root root 512 Feb 13 17:54 vacpp
drwxr-xr-x 3 root root 512 Feb 13 17:54 xlf
drwxr-xr-x 3 root root 512 Mar  5 23:24 xlmass
drwxr-xr-x 3 root root 512 Feb 13 17:44 xlsmp

Best,

Jeff

-- 
Jeff Hammond
Argonne Leadership Computing Facility
University of Chicago Computation Institute
jhammond at alcf.anl.gov / (630) 252-5381
http://www.linkedin.com/in/jeffhammond
https://wiki.alcf.anl.gov/parts/index.php/User:Jhammond