Static cache simulation and its applications

This work takes a fresh look at the simulation of cache memories. It introduces the technique of static cache simulation that statically predicts a large portion of cache references. To e ciently utilize this technique, a method to perform e cient on-they analysis of programs in general is developed and proved correct. This method is combined with static cache simulation for a number of applications. The application of fast instruction cache analysis provides a new framework to evaluate instruction cache memories that outperforms even the fastest techniques published. Static cache simulation is shown to address the issue of predicting cache behavior, contrary to the belief that cache memories introduce unpredictability to real-time systems that cannot be e ciently analyzed. Static cache simulation for instruction caches provides a large degree of predictability for real-time systems. In addition, an architectural modi cation through bit-encoding is introduced that provides fully predictable caching behavior. Even for regular instruction caches without architectural modi cations, tight bounds for the execution time of real-time programs can be derived from the information provided by the static cache simulator. Finally, the debugging of real-time applications can be enhanced by displaying the timing information of the debugged program at breakpoints. The timing information is determined by simulating the instruction cache behavior during program execution and can be used, for example, to detect missed deadlines and locate time-consuming code portions. Overall, the technique of static cache simulation provides a novel approach to analyze cache memories and has been shown to be very e cient for numerous applications. 1 Acknowledgements I would like to to express my gratitude to Dr. David Whalley, my major professor, for his guidance, support, patience, and promptness during my work on this dissertation. He was always available to discuss new problems and exchange ideas. I would also like to thank the other committee members, Dr. Ted Baker, Dr. Gregory Riccardi, and Dr. Steve Bellenot, for their kind support. Dr. Baker introduced me to the area of real-time systems, one of the application areas of the dissertation work. His comments on early drafts of the formalizations in this dissertation were most valuable. Dr. Riccardi helped me to organize my thoughts and improve the presentation style of this dissertation. Last but not least, Dr. Bellenot's input on the formalization and proofs of the graph-theoretical aspects were invaluable. 2