FLUPS - A Flexible and Performant Massively Parallel Fourier Transform Library

Massively parallel Fourier transforms are widely used in computational sciences, and specifically fluid dynamics which involves unbounded Poisson problems. In practice the latter is usually most time-consuming operation due to its inescapable all-to-all communication pattern. The original flups library tackles that issue with an implementation of distributed transform tailor-made for successive resolutions However proposed lacks flexibility as it only supports cell-centered data layout features a plain strategy. This work extends along two directions. First, ' generalized support node-centered layout. Second, three distinct approaches provided handle communications: one all-to-all, non-blocking implementations relying on manual packing xmlns:xlink="http://www.w3.org/1999/xlink">MPI_Datatype communicate over network. software validated against analytical solutions unbounded, semi-unbounded, periodic domains. performance then compared xmlns:xlink="http://www.w3.org/1999/xlink">accFFT , another FFT implementation, using case. Finally metrics each analyzed detailed various top-tier European facilities up 49,152 cores. brings fully production-ready performant library, featuring all possible types FFTs data-layout. code available under BSD-3 license at github.com/vortexlab-uclouvain/flups .