VPC prediction: reducing the cost of indirect branches via hardware-based dynamic devirtualization

Indirect branches have become increasingly common in modular programs written in modern object-oriented languages and virtualmachine based runtime systems. Unfortunately, the prediction accuracy of indirect branches has not improved as much as that of conditional branches. Furthermore, previously proposed indirect branch predictors usually require a significant amount of extra hardware storage and complexity, which makes them less attractive to implement. This paper proposes a new technique for handling indirect branches, called Virtual Program Counter (VPC) prediction. The key idea of VPC prediction is to treat a single indirect branch as multiple “virtual” conditional branches in hardware for prediction purposes. Our technique predicts each of the virtual conditional branches using the existing conditional branch prediction hardware. Thus, no separate storage structure is required for predicting indirect branch targets. Our evaluation shows that VPC prediction improves average ...

• Type: Conference
• Year: 2007
• Where: ISCA
• Authors: Hyesoon Kim, José A. Joao, Onur Mutlu, Chang Joo Lee, Yale N. Patt, Robert Cohn
• Keywords: Hardware, Indirect Branch, Indirect Branches, ISCA 2007, VPC Prediction