Improving Convolution via Cache Hierarchy Tiling and Reduced Packing
Victor Ferrari, Rafael T. de Sousa, Marcio Machado Pereira, João P. L. de Carvalho, José Nelson Amaral, Guido Costa Souza De Araujo · 2022
Convolution is one of the most computationally intensive machine learning model operations, usually solved by the known Im2Col + BLAS method. This work proposes a novel convolution-algorithm to improve upon Im2Col + BLAS by introducing (a) CSA: a convolution specific 3D cache-blocking analysis that focuses on tile reuse over the cache hierarchy, (b) CSO: a macro-kernel that follows CSA to compute the convolution by tiling it, (c) a specialized microkernel that seeks to achieve peak hardware performance, and (d) packing routines for the input tensor and filters to bridge the gap between tiling and micro-kernel. Our approach speeds up end-to-end machine learning model inference by up to 26% and 21% for x86 and POWER10 architectures, respectively.