Kokkos-FFT

Kokkos-FFT is a library which started development in December 2023, as a part of the CExA project, and is now an official part of the Kokkos project (and thus of HPSF). Its initial goals were to offer access to a Kokkos-aware performance-driven and portable FFT, with an API as simple as possible. It has been done by building an API inspired by NumPy FFT, which dispatch work to existing FFT libs (such as cufft, hipfft, FFTW, or onemkl), choosing the appropriate one depending on the current Kokkos backend. This API is designed to be safe to use, with as much compile-time and runtime checks as possible. Kokkos-FFT takes advantage of Kokkos to offer support for multi dimensional arrays with up to 8 dimensions. It also supports real to real, real to complex and complex to real transformations. Kokkos-FFT is thoroughly tested and offers an extensive documentation, it is also easy to build, most of the compilation flags coming directly from the Kokkos installation you link against. It recently reached an important milestone with the release of the 1.0 version, making it production ready. This presentation will serve to: - showcase the API, its ease of use, and the way it integrates in a Kokkos project, - present performances results, - present ongoing work regarding the distribution of FFT across several nodes using MPI and other collective communication libraries.