Towards minimizing execution delays on dynamically reconfigurable processors: a case study on REDEFINE

In Dynamically Reconfigurable Processors (DRPs), compilation involves breaking an application into sub-tasks for piecewise execution on the fabric. These sub-tasks are sequenced based on data and control dependences. In DRPs, sub-task prefetching is used to hide the reconfiguration time while another sub-task executes. In REDEFINE, our target DRP, subtasks are referred to as HyperOps. Determining the successor for a HyperOp requires merging information from the control flow graph and the HyperOp dataflow graph. Succession in many cases is data dependent. Since hardware branch predictors cannot be applied due to the non-binary branches, we employ a speculative prefetch unit together with a profile based prediction scheme. Simulation results show around 7-33% reduction in overall execution time, when compared to the execution time without prefetching. We observe better performance when fewer resources on the fabric are used to execute prefetched HyperOps.