Cluster-Based Heuristic for High Level Synthesis Design Space Exploration

High Level Synthesis (HLS) frameworks allow to describe hardware designs in a high-level language (C/C++), without burdening developers with the error-prone task of specifying their implementation in detail. The HLS process is usually controlled by user-specified directives, which influence the implementation area and latency. Nonetheless, the correlation between directives and performance is often difficult to foresee and to quantify. Addressing this challenge, we herein propose a heuristic that, by only exploring a subset of possible configurations for an HLS design, is able to retrieve a close approximation of its Pareto Frontier of non-dominated implementations. Our framework identifies regions of interest in the design space, and iteratively searches for new solutions within such regions, or in their combinations. Experimental evidence across multiple benchmarks showcases that our approach to HLS design space exploration reaches better Pareto approximations, and with less required synthesis runs, with respect to State of the Art alternatives.