Proceedings of the 22nd International Conference on Parallel Architectures and Compilation Techniques (2009)
Raleigh, North Carolina, USA
Sept. 12, 2009 to Sept. 16, 2009
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/PACT.2009.29
The speed gap between processor and memory continues to limit performance. To address this problem, we explore the potential of eliminating Zero Loads — loads accessing memory locations that contain the value “zero” — to improve performance and energy dissipation. Our study shows that such loads comprise as many as 18% of the total number of dynamic loads. We show that a significant fraction of zero loads ends up on the critical memory-access path in out-of-order cores. We propose a non-speculative microarchitectural technique — Zero-Value Cache (ZVC) — to capitalize on zero loads and explore critical design options of such caches. We show that with modest investment, we can obtain speedups up to 78% and reduce the overall energy dissipation by up to 39%. Most importantly, zero-value caches never cause performance loss.
Zero-Value Cache, Load Scheduling, Load Criticality, Frequent Value Locality, Zero Load
Mafijul Md. Islam, Per Stenstrom, "Zero-Value Caches: Cancelling Loads that Return Zero", Proceedings of the 22nd International Conference on Parallel Architectures and Compilation Techniques, vol. 00, no. , pp. 237-245, 2009, doi:10.1109/PACT.2009.29