Predictive sequential associative cache

In this paper we propose a cache design that provides the same miss rate as a two-way set associative cache, but with an access time closer to a direct-mapped cache. As with other designs, a traditional direct-mapped cache is conceptually partitioned into multiple banks, and the blocks in each set are probed, or examined, sequentially. Other designs either probe the set in a fixed order or add extra delay in the access path for all accesses. We use prediction sources to guide the cache examination, reducing the amount of searching and thus the average access latency. A variety of accurate prediction sources are considered, with some being available in early pipeline stages. We feel that our design offers the same or better performance and is easier to implement than previous designs.