Predictive techniques for aggressive load speculation
Predictive techniques for aggressive load speculation
复制标题
激进负载推测的预测技术
DOI：
10.1109/micro.1998.742775
复制
发表时间：
1998
期刊：
影响因子：
--
通讯作者：
B. Calder
中科院分区：
文献类型：
--
作者：
G. Reinman;B. Calder
加载延迟仍然是动态调度流水线处理器中的一个重要瓶颈。已经提出了负载推测技术来减少这种延迟。依赖预测可以用来允许在所有先前的存储地址已知之前发出加载，并准确预测加载应该等待哪个存储。地址预测可用于允许加载绕过其有效地址的计算并推测性地发出。值预测可用于绕过加载转发延迟并避免缓存未命中。内存重命名已经被提出来将存储的值直接传递给别名加载。在本文中，我们详细研究了这四个负载推测技术的存在下，两个错过投机恢复体系结构重新执行和挤压的相互作用和性能权衡。我们研究这些技术相结合的性能，以创建一个负载推测并行计算器，它提供了使用任何一种技术在隔离的性能改善。我们还研究了预测数据缓存未命中这些负载推测技术的准确性。
Load latency remains a significant bottleneck in dynamically scheduled pipelined processors. Load speculation techniques have been proposed to reduce this latency. Dependence Prediction can be used to allow loads to be issued before all prior store addresses are known, and to predict exactly which store a load should wait upon. Address Prediction can be used to allow a load to bypass the calculation of its effective address and speculatively issue. Value Prediction can be used to bypass the load forward latency and avoid cache misses. Memory renaming has been proposed to communicate stored values directly to aliased loads. In this paper we examine in detail the interaction and performance tradeoffs of these four load speculation techniques in the presence of two miss-speculation recovery architectures-reexecution and squash. We examine the performance of combining these techniques to create a load speculation chooser which provides performance improvement over using any one technique in isolation. We also examine the accuracy of these load speculation techniques for predicting data cache misses.