RISC-V指令集架构(Instruction Set Architecture,ISA)作为一种新兴的精简ISA,因免费、开源、自由等特点而得到快速发展.由于国内外对RISC-V的研究主要集中在硬件开发,软件生态相较于成熟ISA还很薄弱,实现一套RISC-V指令集高性能基础数...RISC-V指令集架构(Instruction Set Architecture,ISA)作为一种新兴的精简ISA,因免费、开源、自由等特点而得到快速发展.由于国内外对RISC-V的研究主要集中在硬件开发,软件生态相较于成熟ISA还很薄弱,实现一套RISC-V指令集高性能基础数学库可以进一步丰富RISC-V软件生态.本文基于自动化移植技术实现申威数学库到RISC-V的移植,为RISC-V指令架构提供首个使用向量指令优化的基础数学库系统.本文提出向量寄存器自动分支查表法与路径标记插入法,重点解决不同架构间寄存器映射过程中的寄存器复用问题,实现寄存器正确高效映射,并依据不同指令等价转换策略自动化移植数学函数69个.测试结果表明,RISC-V基础数学库函数可实现正确计算,最大误差为1.90ULP,函数性能平均为157.03节拍.展开更多
共性数学库PETSc(Portable,Extensible Toolkit for Scientific Computation)是高性能计算的基础模块,是超级计算机计算环境的基础算法库之一,其性能直接影响调用数学库的高性能数值计算应用的效率.面向国际上首台100P神威·太湖之...共性数学库PETSc(Portable,Extensible Toolkit for Scientific Computation)是高性能计算的基础模块,是超级计算机计算环境的基础算法库之一,其性能直接影响调用数学库的高性能数值计算应用的效率.面向国际上首台100P神威·太湖之光异构超级计算机,根据实际研究需要选取PETSc中两个典型用例ex5(单节点线性求解方程组问题)和ex19(多节点求解2D驱动腔问题)进行实验探究.对运行结果分析找到的热点函数主要为PETSc函数库中7个核心函数,针对这7个核心函数(主要包括向量运算与矩阵运算),提出和实现了其异构并行算法,并结合机器的异构体系结构提出了相应的性能优化方法.在超级计算机上的实验结果为:核心函数并行算法在4主核、256从核的单节点上加速比最大可达到16.4;多节点情况下,当输入规模为16 384时,8192个节点相对于256节点的加速比为32,且加速比随着异构处理器数目的增加接近线性增加,表明PETSc核心函数并行算法在神威·太湖之光超级计算机上具有良好的可扩展性.展开更多
[Objective] This study aimed to screen an Na＋/H＋ antiporter gene from the halophiles colonizing in the Dagong Ancient Brine Well in Zigong City, China, and then analyze the gene structure and properties of the prote...[Objective] This study aimed to screen an Na＋/H＋ antiporter gene from the halophiles colonizing in the Dagong Ancient Brine Well in Zigong City, China, and then analyze the gene structure and properties of the protein encoded by this gene. [Method] Metagenomic DNA libraries of halophiles from the Dagong Ancient Brine Well were used for screening genes with Na＋/H＋ antiporter activity in antiporter-defi- cient E. coil KNabc strain by functional complementation. Then the start codon, stop codon, ORF, -35 region, -10 region and SD sequence of Na~/H＋ antiporter gene, as well as the molecular weight, isoelectric point, hydrophobic region, transmembrane domain, phyletic evolution and salt resistance of protein encoded by the gene were investigated. [Result] A new Na＋/H＋ antiporter gene m-nha was obtained, which ,ren- dered the antiporter-negative mutant E. coil KNabc cells with both the resistance to Na＋ and the ability to grow under alkaline conditions. [Conclusion] The structure and amino acid sequence of M-Nha was different from the previously reported Na＋/H~ antiporters, and the m-nha gene disclosed from the Dagong Ancient Brine Well was identified as a novel Na＋/H＋ antiporter gene. This study was significant not only in helping us understand the salt tolerance of halophiles in ancient brine wells and develop and utilize the genes resource, but also in exploring new salt-tolerant genes.展开更多
文摘RISC-V指令集架构(Instruction Set Architecture,ISA)作为一种新兴的精简ISA,因免费、开源、自由等特点而得到快速发展.由于国内外对RISC-V的研究主要集中在硬件开发,软件生态相较于成熟ISA还很薄弱,实现一套RISC-V指令集高性能基础数学库可以进一步丰富RISC-V软件生态.本文基于自动化移植技术实现申威数学库到RISC-V的移植,为RISC-V指令架构提供首个使用向量指令优化的基础数学库系统.本文提出向量寄存器自动分支查表法与路径标记插入法,重点解决不同架构间寄存器映射过程中的寄存器复用问题,实现寄存器正确高效映射,并依据不同指令等价转换策略自动化移植数学函数69个.测试结果表明,RISC-V基础数学库函数可实现正确计算,最大误差为1.90ULP,函数性能平均为157.03节拍.
基金Supported by Chunhui Plan of Ministry of Education(Z2010101)Open Fund of Food Biotechnology Key Laboratory of Sichuan Province(SZJJ2009-014)Scientific Research Foundation of Xihua University(000022)~~
文摘[Objective] This study aimed to screen an Na＋/H＋ antiporter gene from the halophiles colonizing in the Dagong Ancient Brine Well in Zigong City, China, and then analyze the gene structure and properties of the protein encoded by this gene. [Method] Metagenomic DNA libraries of halophiles from the Dagong Ancient Brine Well were used for screening genes with Na＋/H＋ antiporter activity in antiporter-defi- cient E. coil KNabc strain by functional complementation. Then the start codon, stop codon, ORF, -35 region, -10 region and SD sequence of Na~/H＋ antiporter gene, as well as the molecular weight, isoelectric point, hydrophobic region, transmembrane domain, phyletic evolution and salt resistance of protein encoded by the gene were investigated. [Result] A new Na＋/H＋ antiporter gene m-nha was obtained, which ,ren- dered the antiporter-negative mutant E. coil KNabc cells with both the resistance to Na＋ and the ability to grow under alkaline conditions. [Conclusion] The structure and amino acid sequence of M-Nha was different from the previously reported Na＋/H~ antiporters, and the m-nha gene disclosed from the Dagong Ancient Brine Well was identified as a novel Na＋/H＋ antiporter gene. This study was significant not only in helping us understand the salt tolerance of halophiles in ancient brine wells and develop and utilize the genes resource, but also in exploring new salt-tolerant genes.
