Efficient Run Time Optimization with Static Single Assignment

Abstract

We introduce a novel optimization engine for META4, a new object oriented language currently under development. It uses Static Single Assignment (henceforth SSA) form coupled with certain reasonable, albeit rare language features. The result is a reduction of the optimizer’s code footprint and an increase of its “reuse” factor. This engine performs the following optimizations; Dead Code Elimination (DCE), Common Subexpression Elimination (CSE) and Constant Propagation (CP). It performs these optimizations at both runtime and compile time with linear complexity time. Also, CP is essentially free, whether the values are really source-code constants or specific values generated at runtime. CP runs along side with the other optimization passes, thus allowing the efficient runtime specialization of the code during any point of the program’s lifetime.