Enhanced Dependence Graph Model for Critical Path Analysis on Modern Out-of-Order Processors

Abstract

The dependence graph model of out-of-order (OoO) instruction execution is a powerful representation used for the critical path analysis. However most, if not all, of the previous models are out-of-date and lack enough detail to model modern OoO processors, or are too specific and complicated which limit their generality and applicability. In this paper, we propose an enhanced dependence graph model which remains simple but greatly improves the accuracy over prior models. The evaluation results using the gem5 simulator show that the proposed enhanced model achieves CPI error of 2.1 percent which is a 90.3 percent improvement against the state-of-the-art model.