JVM Virtual Method Invoking Optimization Based on CAM Table

Abstract

In Java programs, it needs to use the information of the method type to resolve the virtual method dynamically, which restricts the performance greatly. Currently, the solution is mainly the technique of inline caching, which can be divided into two categories: monomorphic inline caching and polymorphic inline caching. Because of the simple implementation of monomorphic inline caching, it is more commonly used, but it cannot resolve the problem of frequently seeing different types of objects at one call site. Although polymorphic inline caching can solve this problem, it is costly. This paper presents the CAM hardware table, proposes a virtual method invoking mechanism based on software and hardware co-design. It solves the problem of frequently seeing different types of objects at one call site, and does not introduce additional overhead. The experimental evaluation shows that it improves the cached hit rate from 13.3% to 76.4% and improves 16.2% performance of the virtual test, it improves the performance of SPECjvm 98 by 6.4% on average.