Accurate and Fast Performance Modeling of Processors with Decoupled Front-end

Various techniques, such as cache replacement algorithms and prefetching, have been studied to prevent instruction cache misses from becoming a bottleneck in the processor frontend. In such studies, the goal of the design has been to reduce the number of instruction cache misses. However, owing to the increasing complexity of modern processors, the correlation between reducing instruction cache misses and reducing the number of executed cycles has become smaller than in previous cases. In this paper, we propose a new guideline for improving the performance of modern processors. In addition, we propose a method for estimating the approximate performance of a design two orders of magnitude faster than a full simulation each time the designers modify their design.