TY  - CONF
AU  - Lengvenis, Arijus
AU  - Dachsel, Holger
AU  - Morgenstern, Laura
AU  - Kabadshow, Ivo
TI  - A New Spin on the Fast Multipole Method for GPUS: Rethinking the Far-Field Operators
PB  - IEEE
M1  - FZJ-2025-05346
SP  - 12 p.
PY  - 2025
AB  - The Fast Multipole Method (FMM) is an optimally efficient algorithm for solving N -body problems: a fundamental challenge in fields like astrophysics, plasma physics and molecular dynamics. It is particularly suited for computing 1/r potentials present in Coulomb and gravitational particle systems. Despite the near-field phase being trivially parallelisable, the far-field phase of the 1/r FMM currently lacks an efficient, massively parallel GPU algorithm fitting for the era of Exascale computing. Current state-of-the-art approaches either favor highly parallel but inefficient expansion shift operators or asymptotically efficient but poorly parallelisable rotation-based ones. Recently, a breakthrough was made with the re-evaluation of a rotation operator variant called fast rotation, which dramatically increases caching effectiveness and marries the advantages of both methods. Thus, this paper incorporates this approach to create fast rotation-based operators that facilitate an efficient far-field algorithm for the FMM on GPUs. Additionally, a warpcentric data access scheme is co-developed alongside a matching octree design, which yields coalesced memory access patterns for the bottleneck operators of the far-field phase. The fast rotation algorithm is enhanced with a cache-tiling mechanism, maximising GPU cache utilisation. Compared to the state-of-theart GPU FMM far-field implementation, our algorithm achieves lower running times across the board and a 2.47 x speedup for an increased precision simulation, with the performance improvement growing as precision increases, providing concrete proof of efficacy for dense particle systems.
T2  - 2025 IEEE International Parallel and Distributed Processing Symposium
CY  - 3 Jun 2025 - 7 Jun 2025, Milano (Italy)
Y2  - 3 Jun 2025 - 7 Jun 2025
M2  - Milano, Italy
LB  - PUB:(DE-HGF)8
DO  - DOI:10.1109/IPDPS64566.2025.00075
UR  - https://juser.fz-juelich.de/record/1049542
ER  -