Folding active list for high performance and low power

Abstract

Out-of-order processors schedule instructions dynamically in order to exploit instruction level parallelism. It is necessary to increase instruction window size for improving instruction scheduling capability. In addition, current trend of exploiting thread-level parallelism requires further large instruction window. However, it is difficult to increase the size, because the instruction window is one of the dominant deciding processor cycle time and power consumption. This paper proposes a large instruction window, focusing on power-aware active list with large capacity. Restricting allocation and commitment policies, we achieve both high performance and low power. Simulation results show that our proposed active list significantly boosts processor performance with slight degradation from the traditional unrealistic active list. © Springer-Verlag Berlin Heidelberg 2008.