Thread fusion

Abstract

This work proposes Thread Fusion as an effective way of reducing power consumption when a Simultaneous Multi-Threaded (SMT) core is executing two threads from a homogeneous parallel application. Two dynamic instances of the same static instruction, each from a different thread are merged (fused) into a single instruction, consuming half of the resources of front-end pipeline stages. When the fused instruction is executed, it is cloned and it proceeds at full bandwidth. Our simulation results show average energy reduction of 10% with less than 1% impact on performance.