Dependencies

SimiLie relies on git submodule to manage its dependencies and on cmake as a build system. It is a lightweight header-only library. It can thus be included as a dependency of your project with the cmake command-line:

add_subdirectory(vendor/similie)

By including the header file similie.hpp in your code, you get access to:

Kokkos in the Kokkos:: namespace, a performance-portable (CPU & GPU) C++ library targeting all major HPC platforms.
DDC in the ddc:: namespace, an abstraction layer build upon Kokkos to provide labeling of dimensions of arrays and convenient API to describe discrete scalar fields (+ computation kernels for FFT and splines).
SimiLie itself in the sil:: namespace.

Moreover, parts of SimiLie [are planned to] relie on the FFT and splines kernels provided by DDC. The first is build upon kokkos-fft and the second upon kokkos-kernels or Ginkgo, depending on the linear algebra backend you want to use. Unfortunalty, at this moment DDC does not support linking only one of those two backends, thus you need a complete install of Ginkgo 1.8 to run SimiLie even if you do not plan to use it (this dependency is not provided as a git submodule, due to its weight). DDC FFT and splines kernels also require FFTW and LAPACKE, that are nor provided as git submodules.

I/O are handled by the Decl'HDF5 plugin of PDI, that is nor provided as a git submodule.

Finally, the sil::young_tableau module relies on the embed directive from C23. As it is not yet in C++ (even in C++26), the only supported compiler for this module at the moment seems to be Clang 19. Thus, by default the BUILD_YOUNG_TABLEAU flag is turned OFF and this feature (which is quite independant of the rest of the SimiLie library) is not compiled, making SimiLie a C++20 library.

Attention: A Spack-based toolchain is provided here to get a complete environment for Ubuntu 24 and Nvidia V100 GPU. It can be easily adapted to other OS/hardware.

Compilation

First, be sure to have a full install of FFTW, LAPACKE, Ginkgo and PDI. Then clone the main branch of the github repo and populate the other dependencies with:

git clone --recurse-submodules git@github.com:blegouix/similie.git

Make a build/ folder, cd build/ and run the command:

cmake -DCMAKE_CXX_COMPILER=g++-13 -DCMAKE_BUILD_TYPE=Debug -DKokkos_ENABLE_OPENMP=ON ..

for CPU compilation or:

cmake -DCMAKE_CXX_COMPILER=../vendor/ddc/vendor/kokkos/bin/nvcc_wrapper -DCMAKE_BUILD_TYPE=Debug -DKokkos_ENABLE_CUDA=ON -DKokkos_ARCH_<YOUR_ARCH_NAMECODE>=ON ..

for Nvidia GPU compilation. <YOUR_ARCH_NAMECODE> must be replaced with a hardware-specific namecode that you will find here.

Important: Debug mode is strongly recommended during development because a lot of assertions guarantee the correct usage of library. Running in Release mode without having checked first the proper execution in Debug mode may result to silent bugs. Release mode is of course required at a later stage to get full performance.

You can then edit the configuration with ccmake .. Please refer to the documentations of Kokkos and DDC for their respective cmake compilation flags.

Finally compile with the make command (with -j flag for parallel compilation).

Usage

Tests chain can be run with:

ctest

A particular test with:

ctest -R NameOfTheTest --verbose

And examples are compiled in the examples/ folder.