A Comparison of Dynamic Branch Predictors that Use Two Levels of Branch History

Recent attention to speculative execution as a mechanism for increasing performance of single instruction streams has demanded substantially better branch prediction than what has been previously available. We 1, 2] and Pan, So, and Rahmeh 4] have both proposed variations of the same aggressive dynamic branch predictor for handling those needs. We call the basic model Two-Level Adaptive Branch Prediction Pan, So, and Rahmeh call it Correlation Branch Prediction. In this paper, we adopt the terminology of 2] and show that there are really nine variations of the same basic model. We compare the nine variations with respect to the amount of history information kept. We study the e ects of di erent branch history lengths and pattern history table con gurations. Finally, we evaluate the cost e ectiveness of the nine variations.

• Type: Conference
• Year: 1993
• Where: ISCA
• Authors: Tse-Yu Yeh, Yale N. Patt
• Keywords: Branch Prediction, Branch Prediction Pan, Correlation Branch Prediction, Hardware, ISCA 1993