Energy-aware register file re-partitioning for clustered VLIW architectures

VLIW architectures have gained acceptance in embedded systems. Traditional monolithic register file is not suitable for VLIW architectures with a large number of functional units. Clustered VLIW architecture is often applied, where the register file is partitioned into a number of smaller register files. Register files represent a substantial portion of the energy consumption in modern processors, and it is growing rapidly with wider instruction width. Most of the known clustered VLIW architectures partition the register file evenly among clusters. In this paper, we study the effect of energy consumption with register file re-partitioning on clustered VLIW architecture, where register files are not necessarily partitioned evenly. We present algorithms to compute energy-efficient re-partition of register files under different conditions. The impact of different intercluster communication models as well as the impact of program behavior on the register file re-partitioning are analyzed in this paper. Experimental results show that energy saving can be achieved using the proposed techniques.