ROSE: The Design of a General Tool for the Independent Optimization of Object-Oriented Frameworks

ROSE represents a programmable preprocessor for the highly aggressive optimization of C++ object-oriented frameworks. A fundamental feature of ROSE is that it preserves the semantics, the implicit meaning, of the object-oriented framework's abstractions throughout the optimization process, permitting the framework's abstractions to be recognized and optimizations to capitalize upon the added value of the framework's true meaning. In contrast, a C++ compiler only sees the semantics of the C++ language and thus is severely limited in what optimizations it can introduce. The use of the semantics of the framework's abstractions avoids program analysis that would be incapable of recapturing the framework's full semantics from those of the C++ language implementation of the application or framework. Just as no level of program analysis within the C++ compiler would not be expected to recognize the use of adaptive mesh refinement and introduce optimizations based upon such information. Since ROSE is programmable, additional specialized program analysis is possible which then compliments the semantics of the framework's abstractions. Enabling an optimization mechanism to use the high level semantics of the framework's abstractions together with a programmable level of program analysis (e.g. dependence analysis), at the level of the framework's abstractions, allows for the design of high performance object-oriented frameworks with uniquely tailored sophisticated optimizations far beyond the limits of contemporary serial F0RTRAN 77, C or C++ language compiler technology. In short, faster, more highly aggressive optimizations are possible. The resulting optimizations are literally driven by the framework's definition of its abstractions. Since the abstractions within a framework are of third party design the optimizations are similarly of third party design, specifically independent of the compiler and the applications that use the framework. The interface to ROSE is particularly simple and takes advantage of standard compiler technology. ROSE acts like a preprocessor, since it must parse standard C++{sup 1}, and its use is optional, it can not be used to introduce any new language features. ROSE reads standard C++ source code and outputs standard C++ code. Its use is always optional, by design: so as not to interfere with and to remain consistent with the object-oriented framework. It is a mechanism to introduce optimizations only; adding language features using ROSE is by design no more possible than within the framework itself. Importantly, since ROSE generates C ++ code it does not preclude the use of other tools or mechanisms that would work with an application source code (including template mechanisms)