Class Hierarchy Specialization

Abstract

Class libraries are generally designed with an emphasis on versatility and extensibility. Applications that use a library typically exercise only part of the library's functionality. As a result, objects created by the application may contain unused members. We present an algorithm that specializes a class hierarchy with respect to its usage in a program P. That is, the algorithm analyzes the member access patterns for P's variables, and creates distinct classes for variables that access different members. Class hierarchy specialization reduces object size, and is hence primarily a space optimization. However, execution time may also be reduced through reduced object creation/destruction time, and caching/paging effects.