Automatic data layout for high performance Fortran

1995 ◽  
Author(s):  
Ken Kennedy ◽  
Ulrich Kremer
Keyword(s):  
High Performance ◽  
Data Layout ◽  
Automatic Data ◽  
High Performance Fortran

scholarly journals DDT: A Research Tool for Automatic Data Distribution in High Performance Fortran

1997 ◽  
Vol 6 (1) ◽  
pp. 73-94 ◽  
Author(s):  
Eduard AyguadÉ ◽  
Jordi Garcia ◽  
MercÉ GironÈs ◽  
M. Luz Grande ◽  
JesÚs Labarta
Keyword(s):  
High Performance ◽  
Data Distribution ◽  
Control Flow ◽  
Research Tool ◽  
Automatic Data ◽  
Computation Cost ◽  
Data Movement ◽  
High Performance Fortran ◽  
Automatic Data Distribution ◽  
The Cost

This article describes the main features and implementation of our automatic data distribution research tool. The tool (DDT) accepts programs written in Fortran 77 and generates High Performance Fortran (HPF) directives to map arrays onto the memories of the processors and parallelize loops, and executable statements to remap these arrays. DDT works by identifying a set of computational phases (procedures and loops). The algorithm builds a search space of candidate solutions for these phases which is explored looking for the combination that minimizes the overall cost; this cost includes data movement cost and computation cost. The movement cost reflects the cost of accessing remote data during the execution of a phase and the remapping costs that have to be paid in order to execute the phase with the selected mapping. The computation cost includes the cost of executing a phase in parallel according to the selected mapping and the owner computes rule. The tool supports interprocedural analysis and uses control flow information to identify how phases are sequenced during the execution of the application.

scholarly journals Scientific Programming with High Performance Fortran: A Case Study Using the xHPF Compiler

1997 ◽  
Vol 6 (1) ◽  
pp. 127-152
Author(s):  
Eric De Sturler ◽  
Volker Strumpen
Keyword(s):  
High Performance ◽  
Parallel Implementation ◽  
Gaussian Elimination ◽  
Primary Objective ◽  
Matrix Product ◽  
Dense Matrix ◽  
High Performance Fortran ◽  
Partial Pivoting ◽  
Intel Paragon

Recently, the first commercial High Performance Fortran (HPF) subset compilers have appeared. This article reports on our experiences with the xHPF compiler of Applied Parallel Research, version 1.2, for the Intel Paragon. At this stage, we do not expect very High Performance from our HPF programs, even though performance will eventually be of paramount importance for the acceptance of HPF. Instead, our primary objective is to study how to convert large Fortran 77 (F77) programs to HPF such that the compiler generates reasonably efficient parallel code. We report on a case study that identifies several problems when parallelizing code with HPF; most of these problems affect current HPF compiler technology in general, although some are specific for the xHPF compiler. We discuss our solutions from the perspective of the scientific programmer, and presenttiming results on the Intel Paragon. The case study comprises three programs of different complexity with respect to parallelization. We use the dense matrix-matrix product to show that the distribution of arrays and the order of nested loops significantly influence the performance of the parallel program. We use Gaussian elimination with partial pivoting to study the parallelization strategy of the compiler. There are various ways to structure this algorithm for a particular data distribution. This example shows how much effort may be demanded from the programmer to support the compiler in generating an efficient parallel implementation. Finally, we use a small application to show that the more complicated structure of a larger program may introduce problems for the parallelization, even though all subroutines of the application are easy to parallelize by themselves. The application consists of a finite volume discretization on a structured grid and a nested iterative solver. Our case study shows that it is possible to obtain reasonably efficient parallel programs with xHPF, although the compiler needs substantial support from the programmer.

HPFIT: A set of integrated tools for the parallelization of applications using High Performance Fortran. Part I: HPFIT and the TransTOOL environment

1997 ◽  
Vol 23 (1-2) ◽  
pp. 71-87 ◽  
Author(s):  
T. Brandes ◽  
S. Chaumette ◽  
M.C. Counilh ◽  
J. Roman ◽  
A. Darte ◽  
...  
Keyword(s):  
High Performance ◽  
High Performance Fortran
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