Hierarchical High-Level Synthesis Design Space Exploration with Incremental Exploration Support

One of the biggest advantages of C-Based VLSI design over traditional RT-level design is its ability to automatically generate architectures with different area versus performance characteristics without the need of modifying the original behavioral description. So far previous works have focuses on either pruning the design space or by creating predictive models in combination with different metaheuristics. In this letter, we present a hierarchical method which makes use of modern HLS tool's options to synthesize functions as functional operators in order to explore these separately. Our method therefore explores each function separately and then performs a merging stage in order to obtain the overall dominating results. Moreover our proposed method detects if any changes in the behavioral description have happened between two exploration executions and only explores those functions which have been affected by the source code changes, while the results of the previous exploration are reused, thus enabling for incremental DSE. Results show that our method is very efficient.