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Automatic Scoping of Variables in Parallel Regions of an OpenMP Program

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Shared Memory Parallel Programming with Open MP (WOMPAT 2004)

Part of the book series: Lecture Notes in Computer Science ((LNTCS,volume 3349))

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Abstract

The process of manually specifying scopes of variables when writing an OpenMP program is both tedious and error-prone. To improve productivity, an autoscoping feature was proposed in [1]. This feature leverages the analysis capability of a compiler to determine the appropriate scopes of variables. In this paper, we present the proposed autoscoping rules and describe the autoscoping feature provided in the Sun StudioTM 9 Fortran 95 compiler. To investigate how much work can be saved by using autoscoping and the performance impact of this feature, we study the process of parallelizing PANTA, a 50,000-line 3D Navier-Stokes solver, using OpenMP. With pure manual scoping, a total of 1389 variables have to be explicitly privatized by the programmer. With the help of autoscoping, only 13 variables have to be manually scoped. Both versions of PANTA achieve the same performance.

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Author information

Authors and Affiliations

  1. Sun Microsystems, U.S.A.

    Yuan Lin & Nawal Copty

  2. RWTH Aachen University, Center for Computing and Communication, Seffenter Weg 23, 52074, Aachen, Germany

    Christian Terboven & Dieter an Mey

Authors
  1. Yuan Lin
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  2. Christian Terboven
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  3. Dieter an Mey
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  4. Nawal Copty
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Editor information

Editors and Affiliations

  1. Dept. of Computer Science, University of Houston, 501 Philip G. Hoffman Hall, 4800 Calhoun Rd, 77204-3010, Houston, TX, USA

    Barbara M. Chapman

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© 2005 Springer-Verlag Berlin Heidelberg

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Lin, Y., Terboven, C., Mey, D.a., Copty, N. (2005). Automatic Scoping of Variables in Parallel Regions of an OpenMP Program. In: Chapman, B.M. (eds) Shared Memory Parallel Programming with Open MP. WOMPAT 2004. Lecture Notes in Computer Science, vol 3349. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-31832-3_8

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  • DOI: https://doi.org/10.1007/978-3-540-31832-3_8

  • Publisher Name: Springer, Berlin, Heidelberg

  • Print ISBN: 978-3-540-24560-5

  • Online ISBN: 978-3-540-31832-3

  • eBook Packages: Computer ScienceComputer Science (R0)

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