Active-cycle based register file design for reduced ports and energy

Multi-ported register file helps exploiting instruction-level and thread-level parallelism but brings area, energy and access time pressure. Oriented for superscalar and SMT processor, this paper give a method that is to manage a small auxiliary active value file (AVF) and selectively store physical register values in active cycle (during the time between production and last use). The AVF structure can share the register file access pressure and reduce the number of register ports, is simple to implement, and can filter some writes. It achieves significant energy savings with no impact on frequency and only small IPC loss.