Trace Based Compilation in Interpreter-less Execution Environments

Trace based compilation is a technique used in managed language runtimes to detect and compile frequently executed program paths. The goal is reduced compilation time and improved code quality since only “hot” parts of methods are ever compiled. Trace compilation is well suited for interpreter based runtime environments because the control flow of an application program is highly visible and recordable. In this technical report, we show that trace compilation is also feasible and beneficial in runtime environments without interpreters. We present the implementation of a trace based Java compiler for the meta-circular Maxine Virtual Machine from Sun Microsystems. Maxine uses a tiered compilation strategy. Methods are first compiled with a non optimizing JIT compiler in order to collect profiling information, and then recompiled with an optimizing compiler for long term execution. We record traces via dynamic insertion and removal of instrumentation code in non optimized methods. We then optimize and link recorded traces using the already existing optimizing compiler.