MXV_OPEN_MP
Matrix Vector Multiplication Timings with OpenMP

MXV_OPEN_MP is a FORTRAN90 program which sets up several matrix vector multiplication problems y=A*x, and carries them out using

• "plain vanilla" FORTRAN;
• "plain vanilla" FORTRAN plus OpenMP parallelization;
• the MATMUL FORTRAN90 intrinsic function;
• the MATMUL FORTRAN90 intrinsic function plus OpenMP parallelization;

The calculations are carried out for a variety of matrix shapes and sizes, and the elapsed wall clock time is measured and reported. The results are up to the user to analyze and explain!

Usage:

mxv_open_mp

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Related Data and Programs:

F90_INTRINSICS is a directory of FORTRAN90 programs which illustrate the use of FORTRAN90 intrinsic functions.

FFT_OPEN_MP is a FORTRAN90 program which demonstrates the computation of a Fast Fourier Transform in parallel, using OpenMP.

LINPACK_BENCH is a FORTRAN90 program which measures the time needed to factor and solve a "large" (N=1000) dense linear system of equations, and is used as a benchmark.

MD_OPEN_MP is a FORTRAN90 program which carries out a molecular dynamics simulation using OpenMP.

MXV, a FORTRAN90 program which compares the performance of (DO I, DO J) loops, (DO J, DO I ) loops, and MATMUL for computing the product of an MxN matrix A and an N vector X.

MXV_OPEN_MP is available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version.

OPEN_MP is a directory of FORTRAN90 examples which illustrate the use of the OpenMP application program interface for carrying out parallel computations in a shared memory environment.

OPEN_MP_ITHACA FORTRAN90 programs which illustrate the use of OpenMP on the Virginia Tech ITHACA cluster.

QUAD_OPEN_MP is a FORTRAN90 program which applies a quadrature rule to estimate an integral, and executes in parallel using OpenMP.

SATISFIABILITY_OPEN_MP is a FORTRAN90 program which demonstrates, for a particular circuit, an exhaustive search for solutions of the circuit satisfiability problem, using OpenMP for parallel execution.

SGEFA_OPEN_MP is a FORTRAN90 program which reimplements the SGEFA/SGESL linear algebra routines from LINPACK for use with OpenMP.

TIMER is a directory of FORTRAN90 programs which demonstrate how to compute CPU time or elapsed time.

ZIGGURAT_OPEN_MP, a FORTRAN90 program which demonstrates how the ZIGGURAT library can be used to generate random numbers in an OpenMP parallel program.

Reference:

1. Peter Arbenz, Wesley Petersen,
   Introduction to Parallel Computing - A practical guide with examples in C,
   Oxford University Press,
   ISBN: 0-19-851576-6,
   LC: QA76.58.P47.
2. Rohit Chandra, Leonardo Dagum, Dave Kohr, Dror Maydan, Jeff McDonald, Ramesh Menon,
   Parallel Programming in OpenMP,
   Morgan Kaufmann, 2001,
   ISBN: 1-55860-671-8,
   LC: QA76.642.P32.
3. Barbara Chapman, Gabriele Jost, Ruud vanderPas, David Kuck,
   Using OpenMP: Portable Shared Memory Parallel Processing,
   MIT Press, 2007,
   ISBN13: 978-0262533027,
   LC: QA76.642.C49.

Source Code:

• mxv_open_mp.f90, the source code.
• mxv_open_mp.sh, commands to compile and link the source code.

Examples and Tests:

• mxv_open_mp_nt1.sh, BASH commands to run the program using 1 thread.
• mxv_open_mp_nt1_output.txt, the output file using 1 thread;
• mxv_open_mp_nt2.sh, BASH commands to run the program using 2 threads.
• mxv_open_mp_nt2_output.txt, the output file using 2 threads;
• mxv_open_mp_nt4.sh, BASH commands to run the program using 4 threads.
• mxv_open_mp_nt4_output.txt, the output file using 4 threads;

List of Routines:

• MAIN is the main program for MXV_OPEN_MP.
• TEST01 compares various algorithms for a given matrix size MxN.
• MATGEN generates a random matrix A and vector X.
• MXV_MATMUL computes y = A * x, using the FORTRAN90 MATMUL function.
• MXV_MATMUL_OPEN_MP computes y = A * x, using MATMUL + OpenMP.
• MXV_PLAIN computes y = A * x, using "plain" code.
• MXV_PLAIN_OPEN_MP computes y = A * x, using OpenMP parallel directives.
• TIMESTAMP prints the current YMDHMS date as a time stamp.

You can go up one level to the FORTRAN90 source codes.