MOSAIC: Maximizing ResOurce Sharing in Behavioral Application SpecIfic ProCessors

Abstract

This work presents a method that can quickly determine which hardware accelerators (HWaccs) should be mapped together onto an Application-Specific Instruction Set Processor (ASIP), such that the resources shared among them are maximized. This work in particular targets HWaccs generated from untimed behavioral descriptions for High-Level Synthesis (HLS). Although HLS is a single process synthesis method, our approach is able to force resource sharing among the HWaccs by combining their behavioral descriptions together into a single description based on their potential to share resources. These shared resources include functional units (FUs) like multipliers, adders, and dividers, and also registers. In particular, our proposed flow leads up to 48% in area savings and on average 30%. Because an exhaustive enumeration of all possible combinations can lead to long runtimes, we propose a fast heuristic that leads to comparable results (only 6% worse on average), while being much faster (on average 500×).