PADS: A Pattern-Driven Stencil Compiler-Based Tool for Reuse of Optimizations on GPGPUs

Stencil computations are core of wide range of scientific and engineering applications. A lot of efforts have been put into improving efficiency of stencil calculations on different platforms, but unfortunately it is not easy to reuse. In this paper we present a PAttern-Driven Stencil compiler-based tool and a simple tuning system to reuse those well optimized methods and codes. We also suggest extensions to OpenMP, depicting high-level data structures in order to facilitate recognition of various stencil computation patterns. The PADS allows programmers to rewrite kernel of stencils or reuse source-to-source translator outputs as optimized stencil template codes with related tuning parameters, In addition, PADS consists of a OpenMP to CUDA translator and code generator using optimized template codes. It also obtains architecture-specific parameters to tune stencils across different GPU platforms. To demonstrate our system flexibility and performance portability, we illustrate four different stencil computations, Laplacian operator with Jacobi iterative method, divergence operator, 3 dimension 25 point stencil and a 2D heat equation using ADI method with periodic boundary conditions. PADS succeeds in generating all these four stencil codes using different optimization strategies and delivers a promising performance improvement.