Automatic optimization of communication in compiling out-of-core stencil codes
Rajesh R. Bordawekar, Alok Choudhary, Jagannathan Ramanujam · 1996
In this paper.we describe a technique for optimizing communication for out-of-core distributed memory stencil problems.In these problems, communication may require both inter-processor communication and file 1/0.We show that in certain cases, extra file 1/0 incurred in communication can be completely eliminated by reordering in-core computations.The in-core computation pattern is decided by: (1) how the out-of-core data distributed into in-core slabs (tiling) and (2) how the slabs are accessed.We show that a compiler using the stencil and processor information can choose the tiling parameters and schedule the tile accesses so that theextra file I/O is eliminated and overall performance is improved.1