Polyhedral model based mapping optimization of loop nests for CGRAs

The coarse-grained reconfigurable architecture (CGRA) is a promising platform that provides both high performance and high power-efficiency. The compute-intensive portions of an application (e.g. loops) are often mapped onto CGRA for acceleration. To optimize the mapping of loop nests to CGRA, this paper makes two contributions: i) Establishing a precise CGRA performance model and formulating the loop nests mapping as a nonlinear optimization problem based on polyhedral model, ii) Extracting an efficient heuristic loop transformation and mapping algorithm (PolyMAP) to improve mapping performance. Experiment results on most kernels of the PolyBench and real-life applications show that our proposed approach can improve the performance of the kernels by 21% on average, as compared to one of the best existing mapping algorithm, EPIMap. The runtime complexity of PolyMAP is also acceptable.