Effect of Spatial Locality Prefetching on Structural Locality

The purpose of this research was to analyze the effect that spatial locality prefetching in cache memory has on the structural locality of program memory referencing behavior. To examine this, a software simulator was built to model a proposed two-level cache memory subsystem. The proposed subsystem was designed to use spatial locality prefetching to exploit the structural locality contained in executing computer workloads. New memory referencing models were developed to incorporate the combined use of structural locality and spatial locality prefetching. From these models, equations were derived to predict the hit rates for both caches. Combined with the state transition probabilities of the memory referencing models, measurements from the trace-driven simulations were used to solve the hit probability equations. This research showed that performance gains through structural locality prefetching are still possible even when spatial locality prefetching is being used in the lower level cache.