计算机科学 ›› 2018, Vol. 45 ›› Issue (6A): 562-567.
倪园慧1,陈巍文1,王磊1,邱柯妮1,2
NI Yuan-hui1,CHEN Wei-wen1,WANG Lei1,QIU Ke-ni1,2
摘要: 多级自旋转移力矩磁性存储器(MLC STT-RAM)是一种新型的非易失性存储介质。不同于采用电荷方式来存储信息的SRAM,MLC STT-RAM利用自旋偏振电流通过磁隧道结(MTJ)改变自由层的磁层方向来存储信息,能够天然地避免电磁干扰。文章利用MLC STT-RAM的抗电磁辐射特性,探索在航天抗辐照环境下将其作为存储介质用于寄存器设计。在MLC STT-RAM中,每个存储单元有4种不同的阻抗状态,不同的阻抗状态之间的转换具有不同的能耗和延迟的代价。而传统的基于SRAM的寄存器分配技术并没有考虑不同的写状态转换的影响,其在没有考虑溢出优先级的情况下启发式地选择潜在溢出变量,因此该方法不适合用在MLC STT-RAM的寄存器分配中。针对该问题,提出了一种面向写状态转换的MLC STT-RAM寄存器分配的溢出优化策略。具体来说,首先,通过每个写状态转换频率的线性组合来构成溢出代价模型。然后,根据溢出代价模型针对性地选择溢出变量,选择代价低的变量保存在寄存器中,而代价高的变量倾向于被溢出,从而便实现了面向MLC STT-RAM的寄存器分配策略的优化设计。
中图分类号:
[1]LIANG S,CHUN X,HU J,et al.Write activity reduction on flash main memory via smart victim cache[C]∥Great Lakes Symposium on VLSI Systems.2010:91-94. [2]姚君.STT-RAM缓存优化策略的研究[D].杭州:浙江工业大学,2014. [3]CHABI D,ZHAO W S,JACQUES-OLIVIER K,et al.Design and analysis of radiation hardened sensing circuits for spin transfer torque magnetic memory and logic[J].IEEE Transactions on Nuclear Science,2014,61(6):3258-3264. [4]HUGHES H,BUSSMANN K,MCMARR P J.et al.Radiation studies of spin-transfer torque materials and devices[J].IEEE Transactions on Nuclear Science,2012,59 (6):3027-3033. [5]BISHNOI R,EBRAHIMI M,OBORIL F,et al.Improving write performance for STT-MRAM[J].IEEE Transactions on Magnetics,2016,52(8):1-11. [6]赵巍胜,王昭昊,彭守仲,等.STT-MRAM存储器的研究进展[J].中国科学:物理学力学天文学,2016,46(10):107306. [7]董伟.基于NVM的写操作优化策略研究与设计[D].济南:山东大学,2016. [8]李清安.面向非易失性片上存储的编译技术研究[D].武汉:武汉大学,2013. [9]CHEN Y R,WANG X B,ZHU W Z,et al.Access scheme of multi-level cell spin-transfer torque random access memory and its optimization[C]∥Midwest Symposium on Circuits and Systems.2010:1109-1112. [10]何炎祥,沈凡凡,张军,等.新型非易失性存储器架构的缓存优化方法综述[J].计算机研究与发展,2015,52(6):1225-1241. [11]CHAITIN,AUSLANDER,CHANDRA,et al.P.W.:Register allocation via graph coloring[J].Journal of Computer Languages,1981,238(16):265-266. [12]COOPER K,DASGUPTA A,et al.Tailoring graph-coloring register allocation for runtime compilation[C]∥Code Generation and Optimization.2006:39-49. [13]张军超.相连多寄存器组体系结构上的寄存器分配技术[D].中国科学院研究生院(计算技术研究所),2005. [14]邓宇.基于图着色的存储层次优化技术研究[D].长沙:国防科学技术大学,2007. [15]薛丽萍.基于龙芯I的全局寄存器分配研究[D].中国科学院研究生院(计算技术研究所),2004. [16]FALK H.WCET-aware register allocation based on graph coloring[C]∥Design Automation Conference.2009:726-731. [17]LOU X H,GAO Z,DIMITORV,et al.Demonstration of multilevel cell spin transfer switching in mgo magnetic tunnel junctions[J].Applied Physics Letters,2008,93(24):242-502. [18]ZHAO M Y,XUE Y,YANG C M,et al.Minimizing MLC PCM write energy for free through profiling-based state remapping[C]∥Asia and South Pacific Design Automation Conference.2015:502-507. [19]ZHAO M Y,XUE Y,HU J T,et al.State asymmetry driven state remapping in phase change memory[J].IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems,2016,36(1):27-40. [20]LIU X X,MAO M J,BI X Y,et al.An efficient stt-ram-based register file in gpu architectures[C]∥Asia and South Pacific Design Automation Conference.2015:490-495. [21]LATTNER C,ADVE V.LLVM:A compilation framework for lifelong program analysis & transformation[C]∥Code Generation and Optimization.2004:75-86. [22]LUO H Z,HU J T,SHI L,et al.Two-step state transition minimization for lifetime and performance improvement on MLC STT-RAM[C]∥Design Automation Conference.2016:1-6. |
[1] | 唐镇, 胡勇华, 陆浩松, 王书盈. 基于弱约束指派的DSP寄存器偶对分配算法研究 Research on DSP Register Pairs Allocation Algorithm with Weak Assigning Constraints 计算机科学, 2021, 48(6A): 587-595. https://doi.org/10.11896/jsjkx.200600061 |
[2] | 邱亚琼, 胡勇华, 李阳, 唐镇, 石林. 基于两类寄存器互为缓存方法的DSP寄存器分配溢出处理优化算法 Optimization Algorithm of Complementary Register Usage Between Two Register Classesin Register Spilling for DSP Register Allocation 计算机科学, 2019, 46(6): 196-200. https://doi.org/10.11896/j.issn.1002-137X.2019.06.029 |
[3] | 吴圣宁 李思昆. 嵌入式处理器寄存器分配的一种混合演化算法 计算机科学, 2007, 34(8): 278-280. |
[4] | 刘旸 张兆庆. 栈寄存器分配优化 计算机科学, 2004, 31(3): 158-160. |
|