Interprocedural Placement-Aware Configuration Prefetching for FPGA-Based Systems

One of the major impediments to deploying partially run-time reconfigurable FPGAs as hardware accelerators is the time overhead involved in loading the hardware modules. While configuration prefetching is an effective method that can be employed to reduce this overhead, mispredicted prefetches may worsen the situation by increasing the number of reconfigurations needed. In this paper, we present a static algorithm for configuration prefetching in partially reconfigurable FPGAs that minimizes the reconfiguration overhead. By making use of profiling, the interprocedural control flow graph, and the placement information of hardware modules, our algorithm predicts hardware execution and tries to prefetch hardware modules as early as possible while minimizing the risk of mis-predictions. Our experiments show that our algorithm performs significantly better than current state-of-the-art prefetching algorthms for control-bound applications.