Intel compilers

Intel compilers

C&CZ has bought two licences for concurrent use of the most recent version of the Intel Cluster Studio for Linux. This has been installed in /vol/opt/intelcompilers and is available on a.o. clusternodes en loginservers. The old (2011) version will also be moved to /vol/opt/intelcompilers. To set the environment variables correctly, SH/BASH users must first run:

source /vol/opt/intelcompilers/intel-2014/composerxe/bin/compilervars.sh intel64

and CSH users must run:

setenv arch intel64
source /vol/opt/intelcompilers/intel-2014/composerxe/bin/compilervars.csh intel64

After that, icc -V gives the new version number as output.

Documentation for the previous version (2011)

Compiling Fortran (/opt/intel/bin/ifort)

• Intel Fortran Composer XE 2011 Getting Started Tutorials
• Intel Fortran Compiler XE 12.0 User and Reference Guides

Math Kernel Library (mkl, linking blas, lapack)

• Intel Math Kernel Library for Linux OS User' Guide
  • Linking with the Intel Math Kernel Library
• Intel Math Kernel Library Reference Manual

Intel Cluster Studio 2011

• Intel Cluster Studio 2011 for Linux* OS - index to all local documentation
• Intel® MPI Library for Linux OS Documentation Index

How to create a standalone MKL version of BLAS and LAPACK shared libraries ?

This is described in detail in Building Custom Shared Objects

• Create a new directory (e.g. ~/lib)

 mkdir ~/lib
 cd ~/lib

• Copy these files:

 cp /opt/intel/composerxe/mkl/tools/builder/{makefile,blas_list,lapack_list} ~/lib

• Set the MKLROOT variable (in bash):

 MKLROOT=/opt/intel/mkl
 export MKLROOT

In tcsh use:

 setenv MKLROOT /opt/intel/mkl

• Make the shared libraries libblas_mkl.so and liblapack_mkl.so

 make libintel64 export=blas_list interface=lp64  threading=parallel name=libblas_mkl
 make libintel64 export=lapack_list interface=lp64  threading=parallel name=liblapack_mkl

The options are described here

The newly created libblas_mkl.so and liblapack_mkl.so require

 /opt/intel/lib/intel64/libiomp5.so
 

to work. On the cluster nodes this file is automatically linked when required.

Using the MKL BLAS and LAPACK shared libraries (with Scilab)

This should work for any executable that uses a dynamically linked blas or lapack. We use Scilab as an example.

• Make sure we have an executable, not just a script that calls the executable:

 file scilab-bin

The output looks something like this:

 scilab-bin: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.15 ...

• Determine the exact name that is used by the executable:

 ldd scilab-bin | grep blas

The output could be:

 libblas.so.3gf => ~/sciab-5.4.1/lib/thirdparty/libblas.so.3gf

• Replace the library with a link to the MKL version

 cd ~/sciab-5.4.1/lib/thirdparty/
 rm libblas.so.3gf
 ln -s ~/lib/libblas_mkl.so libblas.so.3gf

Also follow this procedure for lapack.

• To use more than one thread, i.e., for parallel computation, set:

 MKL_NUM_THREADS=4
 export MKL_NUM_THREADS

This example will use 4 cores.

• To check the number of cores available, use:

 cat /proc/cpuinfo | grep processor | wc