The Validation Buffer Microarchitecture for Multithreaded Processors

Multithreaded (MT) processors reduce the waste of issue width by executing instructions from multiple threads at the same time. On the other hand, out-of-order commit (OOC) processors have been recently proposed as an efficient way of avoiding pipeline stalls when a long-latency instruction reaches the commit stage. In this work, we analyze the impact on performance of combining both MT and OOC techniques. We combine the three main models of MT —fine grain, coarse grain, and simultaneous MT—with the Validation Buffer OOC microarchitecture.