Multi: Reduce Energy Overhead of Criticality-Aware Dynamic Instruction Scheduling for Energy Efficiency

Criticality-aware dynamic instruction scheduling (DIS) focuses on prioritizing the execution of critical instructions, thereby significantly improving performance. However, criticality-aware DIS is energy-intensive. Energy overhead mainly comes from the design of DIS strategy and the multi-port tables used for extracting critical instruction slices. In this study, Multi is proposed, which develops an energy-efficient DIS strategy and an adaptive multi-port table coordinated with the DIS strategy to reduce the energy overhead of criticality-aware DIS. Evaluation on the SPEC CPU2017 benchmark shows that Multi outperforms the state-of-the-art work in terms of core energy consumption with a geometric mean reduction of 5.9%. Moreover, post-layout simulation results demonstrate a 61.2% reduction in energy consumption of the proposed adaptive multi-port table. It also proves the applicability of Multi in ultra-wide processors with unified or distributed schedulers, contributing to enhanced energy efficiency.