A portable approach to dynamic optimization in run-time specialization

This paper proposes arun-time bytecode specialization (BCS) technique that analyzes programs and generates specialized programs at run-time in an intermediate language. By using an intermediate language for code generation, a back-end system canoptimize the specialized programs after specialization. The system uses Java virtual machine language (JVML) as the intermediate language, which allows the system to easily achieve practicalportability and to use existing sophisticated just-in-time (JIT) compilers as its back-end. The binding-time analysis algorithm is based on a type system, and covers a non-object-oriented subset of JVML. The specializer generates programs on a per-instruction basis, and can performmethod inlining at run-time. Our performance measurements show that a non-trivial application program specialized at run-time by BCS runs approximately 3–4 times faster than the unspecialized one. Despite the large overhead of JIT compilation of specialized code, we observed that the overall performance of the application can be improved.