REVAMP: A Systematic Framework for Heterogeneous CGRA Realization

Coarse-Grained Reconfigurable Architectures (CGRAs) provide an excellent balance between performance, energy efficiency, and flexibility. However, increasingly sophisticated applications, especially on the edge devices, demand even better energy efficiency for longer battery life.

Most CGRAs adhere to a canonical structure where a homogeneous set of processing elements and memories communicate through a regular interconnect due to the simplicity of the design. Unfortunately, the homogeneity leads to substan- tial idle resources while mapping irregular applications and creates inefficiency. We plan to mitigate the inefficiency by systematically and judiciously introducing heterogeneity in CGRAs in tandem with appropriate compiler support.

We propose REVAMP, an automated design space exploration framework that helps architects uncover and add pertinent heterogeneity to a diverse range of originally homogeneous CGRAs when fed with a suite of target applications. RE- VAMP explores a comprehensive set of optimizations encompassing compute, network, and memory heterogeneity, thereby converting a uniform CGRA into a more irregular architecture with improved energy efficiency. As CGRAs are inherently soft- ware scheduled, any micro-architectural optimizations need to be partnered with corresponding compiler support, which is challenging with heterogeneity. The REVAMP framework extends compiler support for efficient mapping of loop kernels on the derived heterogeneous CGRA architectures.