Filtering of Unnecessary Branch Predictor Lookups for Low-Power Processor Architecture
Efforts to reduce power consumption of processors have gained much attention recently. Dynamic branch predictor, including BTB, is exercised in every instruction cycle, yet branch instructions only constitute a small percentage of instructions during program execution. This paper proposes a novel method to collect the next branch distances of the recent branch instructions at runtime, in order to eliminate unnecessary branch predictor lookups. Simulation results show that the proposed design reduces the energy consumption in the dynamic branch predictor by an average of 56.95% without performance degradation.