Recovery Logics for Speculative Update Global and Local Branch History

摘要

Correct branch prediction is an essential task in modern mi-croarchitectures. In this paper, to additionally increase the prediction accuracy, recovery logics for speculative update branch history are presented. In local or global branch predictors, maintaining speculative update history provides substantial prediction accuracy. However, speculative update history requires a suitable recovery mechanism. This paper proposes recovery logics for speculative update branch history, for both global- and local-history. The proposed solutions provide higher prediction accuracy and guarantee the correctness of program, and they can be efficiently implemented with low hardware costs.