VLASPH: Smoothed Particle Hydrodynamics on VLA SIMD Architectures

In the domain of Computational Fluid Dynamics (CFD), Smoothed Particle Hydrodynamics (SPH) has gained increasing popularity compared with traditional grid-based methods. We have seen an increasing demand to accelerate the SPH method with new architectures. Vector Length Agnostic (VLA) SIMD architecture emerges as a promising solution, adopted in ARM and RISC-V for high-performance computing. This paper introduces vlasph, a Smoothed Particle Hydrodynamics on VLA SIMD architectures. vlasph addresses challenges associated with non-contiguous memory data access, SIMD type conversion, and underutilization of SIMD registers. Our comprehensive evaluations across vector lengths ranging from 128 to 2048 bits demonstrate that vlasph achieves significant speedups, with performance gains of up to 4.81x for 2048-bit vectors.