Using Hardware Counters to Improve Dynamic Compilation

In this paper, we describe our project to explore the use of hardware counters to improve triggering techniques for runtime dynamic code recompilation. The Intel Open Runtime Platform (ORP) was chosen as the target Just In Time (JIT) compilation-capable Java Virtual Machine (JVM). The performance counter library (PCL) implemented by Rudolf Berrendorf et al. was used to retrieve real-time micro-architectural level performance values. Only one of these values, the cycle count, was used in this project. Although, the benchmark performance results were not as good as originally anticipated, the work completed for this project has created an infrastructure that can be easily reused and adopted to use other hardware counter values to create improved compilation triggering mechanisms. We introduce a di#erent and potentially better way of performing runtime profiling in comparison to software-only technique used in the original ORP