Fast and standalone Design Space Exploration for High-Level Synthesis under resource constraints

The very high computing capacity available in the latest Field Programmable Gate Array (FPGA) components allows to extend their application fields, in High-Performance Computing (HPC) as well as in embedded applications. This paper presents a new methodology for Design Space Exploration (DSE) in the context of High-Level Synthesis (HLS) for HPC and embedded systems targeting FPGAs.This new methodology provides very quickly an RTL description of the design under resources constraints. An autonomous flow is described, that performs incremental transformations of the input design description. The low complexity of the transformation evaluation, decision and exploration algorithms, associated with a greedy progression, makes this DSE methodology very fast. Moreover, this methodology respects a strict resource constraint given as bare FPGA primitive amounts. Hence, the generated design fits into the targeted FPGA or a partition of it. Such a methodology leads to autonomous, fast and transparent DSE, all these issues known to limit the use of HLS.Results on several benchmarks highlight the capabilities of our DSE methodology. The results show a high generation time speed-up compared to one other existing HLS approach, while preserving correct performance of the generated circuits.