Compiling Ants

Ants is the nodal neutronics program of the Kraken Framework. It is written in Fortran with a C-based interface for multi-physics data exchange.

Compilation instructions are provided for Linux and Windows.

Linux

• Requires Intel oneAPI Math Kernel Library (oneMKL). MKL is already available on VTT computational clusters. Easy to install on Ubuntu Bionic at least.
  • In order to install Intel oneAPI packages with apt, add the Intel oneAPI repository using these instructions.
  • If installing with apt, the required packages seem to be:

intel-oneapi-mkl-2024.0
intel-oneapi-mkl-devel-2024.0
intel-oneapi-compiler-fortran-2024.0
intel-oneapi-compiler-dpcpp-cpp-2024.0

• The environment variable MKLROOT needs to point to the root of the MKL installation directory. For Linux, see the instructions at Developer Guide for Intel® Math Kernel Library for Linux to automate this process.
  • Basically requires adding source /opt/intel/oneapi/setvars.sh to either ~/.bashrc or ~/Envs/Kraken/bin/postactivate.
  • Again, after modifying your environment, you will need to refresh it. The surest way is to close the current terminal window and continue in a new one.
• On VTT computational clusters one recommended way to configure Intel Fortran compiler and Intel MKL is to load suitable module, for example by appending the following command to to ~/.bash_profile:

module load compiler
module load mkl

• Requires libomp5 (libomp5 and libomp-dev packages on Ubuntu Bionic).
• On Linux use the Makefiles found in bin folder. The temporary files and final executables are placed in different folders for each build/compiler combination (for example, to Ants/bin/Release/ifort/ when compiling with the default Makefile). Therefore, make clean is not necessary when consecutively compiling different builds (make -f <makefile>).
  • Makefile: release build for ifort/icx
  • Makefile_debug: debug build for ifort/icx
  • Makefile_gfortran: release build for gfortran/gcc We strongly recommend NOT using gfortran at the moment as its use seems to lead to erroneous program code.
  • Makefile_gfortran_debug: debug build for gfortran/gcc We strongly recommend NOT using gfortran at the moment as its use seems to lead to erroneous program code.

Windows

• Requires Intel oneAPI Math Kernel Library (oneMKL). On Windows, the recommended way is to install Intel oneAPI Base Toolkit.
• Correct way to set the oneMKL environment on Windows before launching Ants is described here. However, this won't set the environment variables permanently.
• Instead, one can either edit or add the Path-variable in the User variables in the Environment variables to include for example

C:\Program Files (x86)\Intel\oneAPI\mkl\latest\redist\intel64

or

C:\Program Files (x86)\Intel\oneAPI\mkl\latest\bin

• Ants Visual Studio solution file is in the vs2022 folder (ants.sln).
• Always compile either Debug x64 or Release x64 builds, depending on which build is desired.
• It might also be necessary to add for example

C:\Program Files (x86)\Intel\oneAPI\compiler\latest\windows\redist\intel64_win\compiler

or

C:\Program Files (x86)\Intel\oneAPI\compiler\latest\bin

in the Path-variable in order to find the correct libiomp5md.dll when Ants is ran.

• The Visual Studio solution and project files might be unsuitable for all environments with different Visual Studio or compiler versions. These have to be modified accordingly.

Additional notes

• Intel Fortran compilers (both ifort and ifx) have a regression in the 2024.1 release, where the Release makefiles with -nostand option do not compile. To fix this error, either remove the -nostand or use -stand f18 option.