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Patent Title: Method and device for program transformation using class hierarchy transformation based upon type constraint analysis

Assignee: IBM
Patent Number: US6230314
Issue Date: 05-08-2001
Application Number:
File Date:10-02-1997

Abstract: A mechanism is provided that eliminates redundant components from objects of a program. Specifically, the mechanism is capable of detecting situations where a member of a given class is used by some, but not all instances of that class, and the elimination of this member from the instances where it is not needed. This is accomplished by an analysis of the program and its class hierarchy, followed by the construction of a new, specialized class hierarchy and a transformation of the program. These operations preserve the original behavior of the program, and have the effect of "optimizing away" unneeded class members from objects. The invention is also capable of replacing class hierarchies that exhibit virtual inheritance with class hierarchies that only exhibit nonvirtual inheritance, and is applicable across a broad spectrum of inheritance structures. Transformation of virtual into nonvirtual inheritance improves program performance because it reduces the time required to access members that are located in virtual base classes. In addition, it may reduce the space required to represent objects.

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Link to USPTO

IBM Pledge dated 1/11/2005