Automatic Generation of Communications for Redundant Multi-dimensional Data Parallel Redistributions

In this paper we concentrate on embedded parallel architectures with heterogeneous memory management systems combining shared and local memories, and more precisely we focus on efficient data communications between the various architecture parts. We formulate explicit data transfers in a polyhedral context and give several strategies for managing efficient communications for redundantly stored/read data. This allows automatic DMA-style code generation for a variety of data mappings onto parallel processing elements. Our approach is validated on a wide series of data redistribution examples linked with a domain-specific parallelisation framework developed in Thales, SpearDE. We give the solution for efficient data transfers mathematically as well as under the form of generated C code.