SPTCStencil: Unleashing Sparse Tensor Cores for Stencil Computation via Strided Swap

Abstract: Stencil computation, a pivotal numerical method in science and engineering, iteratively updates grid points using weighted neighbor contributions and exhibits strong parallelism for multi-core processors. Current optimization techniques targeting conducting stencil computation on tensor core accelerators incur substantial overheads due to redundant zero-padding during the transformation to matrix multiplication. To address this, we introduce a sparse computation paradigm that eliminates inefficiencies by exploiting specialized hardware units. This paper exploits the sparsity in these matrices as a feature and presents SPTCStencil, a high-performance stencil computation system accelerated by Sparse Tensor Core (SpTCs). SPTCStencil is the first to harness SpTCs for acceleration beyond deep learning domains. First, Our approach generalizes an efficient transformation of stencil computation into matrix multiplications and specializes this conversion for SpTC compatibility through a novel sparsification strategy. Furthermore, SPTCStencil incorporates a high-performance GPU kernel with systematic optimizations designed to maximize efficiency on SpTCs. Experimental evaluations demonstrate that SPTCStencil 5.46$\times$ and Tensor Core-based approaches by 2.00$\times$ on average.