Optimizing Message Sends in Object Oriented Languages through Type Invariant Region Analysis

Abstract. Compilers for Object-Oriented Languages optimize dynamic message sends through run-time type testing when they cannot precisely infer the message receiver type. While run-time type testing optimizes dynamic messages, it still results in redundant type testing. We propose a ow-sensitive analysis which calculates regions in a program where an object's type is statically unknown but invariant. The type check is hoisted at the entry point of a region and its results are shared over all dynamic call-sites in the region. We implemented this optimization in the Vortex compiler and demonstrate its eectiveness on ve large Cecil benchmarks. We observed an average speed-up of 9 % and 18 % speed-up in the best case. 1 Introduction and Related Work Typical programs written in Object-Oriented Programming Languages (OOPLs) result in a large number of dynamic message sends due to lack of static typ