Buffer-referred Data Prefetching: An Effective Approach to Coverage-Driven Prefetching

Jinhyun So, Mi Lu

Abstract: This study about data prefetching focuses on maximizing the performance of modern processors by hiding cache misses. This paper suggests that improving prefetch coverage is an effective approach to achieve the goal. This work proposes to employ two simple buffers, block offset buffer and block address buffer, that leverage prefetch coverage. The offset buffer stores the offset of cache blocks that are accessed recently, while the block address buffer stores the address of cache blocks that are prefetch-issued lately. For the offset buffer, we propose to adopt multiple lengths of delta history in searching offset patterns, compared to using a single length of delta history in global history buffer method. Each offset buffer is used to find a local optimum offset of a page. Besides, all the offset buffers are employed to refer to each other, mining offset patterns from others. Our second proposed buffer, the block address buffer, is hired for aggressive prefetching that can switch to adaptive burst mode occurred in the case of successive accesses to the same page. Our Buffer-referred data Prefetcher (BRP) improves an IPC speedup of 23.2% over a no-prefetching baseline. BRP outperforms the state-of-the-art Signature Path prefetcher by an IPC speedup of 4.2%.