一种低功耗的多端口寄存器文件结构设计

A low power design structure for multi-port register file

为了降低寄存器功耗而不损失处理器性能,提出一种基于读写队列的多体寄存器文件结构(multi-bank register file,MBRF)。该结构使用多个寄存器体来分担多端口的访问压力,并且为每个寄存器体设置相应的读写队列;通过指令分解将读写操作缓存在队列中,从而消除多体结构潜在的访问冲突;采用组合和旁路2种分配策略,减少缓冲队列的长度和对寄存器的读写请求。该结构在一个四发射的超标量模拟器上进行评估。研究结果表明:整个寄存器文件最终节省了52%的功耗,而处理器的IPC损失仅为1.6%。与其他寄存器文件相比,基于读写队列的MBRF结构在多发射处理器应用中具有明显的优势。

To reduce the power of register file without bringing processor performance loss, a novel multi-bank register file（MBRF） based on read and write queue was presented. Several register banks were employed to partake the register file access pressure on multiple ports, a read queue and a write queue were organized for each register bank. The read and write operations were decomposed from each instruction into two queues to avoid the potential access conflicts. In addition, both combining and forwarding dispatch strategies were used to reduce the queue length, as well as read and write requires for registers. The design structure was evaluated on a four-issue superscalar simulator. The results show that the total power of register file is reduced by 52% while the processor IPC loss is just no more than 1.6%. Compared with other register files, the MBRF based on read and write queue takes on an evident advantage in multi-issue processor.