Bounding worst-case instruction cache performance

Abstract

The use of caches poses a difficult tradeoff for architects of real-time systems. While caches provide significant performance advantages, they have also been viewed as inherently unpredictable, since the behavior of a cache reference depends upon the history of the previous references. The use of caches is only suitable for real-time systems if a reasonably tight bound on the performance of programs using cache memory can be predicted. This paper describes an approach for bounding the worst-case instruction cache performance of large code segments. First, a new method called static cache simulation is used to analyze a program's control flow to statically categorize the caching behavior of each instruction. A timing analyzer, which uses the categorization information, then estimates the worst-case instruction cache performance for each loop and function in the program.