Tiling Optimizations for 3D Scientific Computations

Compiler transformations can significantly improve data locality for many scientific programs. In this paper, we show iterative solvers for partial differential equations (PDEs) in three dimensions require new compiler optimizations not needed for 2D codes, since reuse along the third dimension cannotfitin cachefor largerproblemsizes. Tiling is a program transformation compilers can apply to capture this reuse, but successful application of tiling requires selection of non-conflicting tiles and/or padding array dimensions to eliminate conflicts. We present new algorithms and cost models for selecting tiling shapes and array pads. We explain why tiling is rarely needed for 2D PDE solvers, but can be helpful for 3D stencil codes. Experimental results show tiling 3D codes can reduce miss rates and achieve performance improvements of 17

• Type: Conference
• Year: 2000
• Where: SC
• Authors: Gabriel Rivera, Chau-Wen Tseng
• Keywords: Applied Computing, Compilers, Iterative Solvers, SC 2000, Tiling Shapes