Programmability of the HPCS Languages: A Case Study with a Quantum Chemistry Kernel (Extended Version)

Shet, Aniruddha G¹  Elwasif, Wael R¹  Harrison, Robert J¹  Bernholdt, David E¹ 

[1] ORNL

关键词: 97;    ALGORITHMS;    CHEMISTRY;    COMPUTERS;    HARTREE-FOCK METHOD;    IMPLEMENTATION;    PROGRAMMING;    PARALLEL PROCESSING;    MEMORY MANAGEMENT;   

DOI  :  10.2172/931141
RP-ID  :  ORNL/TM-2008/011
PID  :  OSTI ID: 931141
Others  :  TRN: US200813%%295

学科分类：社会科学、人文和艺术（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

As high-end computer systems present users with rapidly increasing numbers of processors, possibly also incorporating attached co-processors, programmers are increasingly challenged to express the necessary levels of concurrency with the dominant parallel programming model, Fortran+MPI+OpenMP (or minor variations). In this paper, we examine the languages developed under the DARPA High-Productivity Computing Systems (HPCS) program (Chapel, Fortress, and X10) as representatives of a different parallel programming model which might be more effective on coming high-performance systems. The application used in this study is the Hartree-Fock method from quantum chemistry, which combines access to distributed data with a task-parallel algorithm and is characterized by significant irregularity in the computational tasks. We present several different implementation strategies for load balancing of the task parallel computation, as well as distributed array operations, in each of the three languages. We conclude that the HPCS languages provide a wide variety of mechanisms for expressing parallelism, which can be combined at multiple levels, making them quite expressive for this problem.