FFT_OPENMP, a C code which demonstrates the computation of a Fast Fourier Transform in parallel, using OpenMP.
On an Apple PowerPC G5 with two processors, the following results were observed:
Threads | N | Time | MegaFLOPS |
---|---|---|---|
1 | 33,554,432 | 32.65 | 128.4 |
2 | 33,554,432 | 19.87 | 211.0 |
4 | 33,554,432 | 19.80 | 211.7 |
In the BASH shell, the program could be run with 2 threads using the commands:
export OMP_NUM_THREADS=2 ./fft_openmp
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
FFT_OPENMP is available in a C version and a C++ version and a FORTRAN90 version.
DIJKSTRA_OPENMP, a C code which uses OpenMP to parallelize a simple example of Dijkstra's minimum distance algorithm for graphs.
FFT_SERIAL, a C code which demonstrates the computation of a Fast Fourier Transform, and is intended as a starting point for implementing a parallel version using OpenMP.
FFTPACK4, a C code which implements the Fast Fourier Transform (FFT) by Paul Swarztrauber and Dick Valent, translated by Andrew Fernandes;
FFTW3, C codes which illustrate the use of the FFTW3 library for Fast Fourier Transforms, by Matteo Frigo and Steven Johnson.
FUNCTIONS_OPENMP, a C code which demonstrates the behavior of a few of the OpenMP library functions.
HEATED_PLATE_OPENMP, a C code which solves the steady (time independent) heat equation in a 2D rectangular region, using OpenMP to run in parallel.
HELLO_OPENMP, a C code which prints out "Hello, world!" using the OpenMP parallel programming environment.
IMAGE_DENOISE_OPENMP, a C code which applies simple filtering techniques to remove noise from an image, carrying out the operation in parallel using OpenMP.
JACOBI_OPENMP, a C code which illustrates the use of the OpenMP application program interface to parallelize a Jacobi iteration solving A*x=b.
julia_set_openmp, a C code which produces an image of a Julia set, using OpenMP to carry out the computation in parallel.
MD_OPENMP, a C code which carries out a molecular dynamics simulation using OpenMP.
MULTITASK_OPENMP, a C code which demonstrates how to "multitask", that is, to execute several unrelated and distinct tasks simultaneously, using OpenMP for parallel execution.
MXM_OPENMP, a C code which computes a dense matrix product C=A*B, using OpenMP for parallel execution.
openmp_test, C codes which use the OpenMP application program interface for carrying out parallel computations in a shared memory environment.
POISSON_OPENMP, a C code which computes an approximate solution to the Poisson equation in a rectangle, using the Jacobi iteration to solve the linear system, and OpenMP to carry out the Jacobi iteration in parallel.
PRIME_OPENMP, a C code which counts the number of primes between 1 and N, using OpenMP for parallel execution.
QUAD_OPENMP, a C code which approximates an integral using a quadrature rule, and carries out the computation in parallel using OpenMP.
RANDOM_OPENMP, a C code which illustrates how a parallel program using OpenMP can generate multiple distinct streams of random numbers.
SATISFY_OPENMP, a C code which demonstrates, for a particular circuit, an exhaustive search for solutions of the circuit satisfy problem, using OpenMP for parallel execution.
SCHEDULE_OPENMP, a C code which demonstrates the default, static, and dynamic methods of "scheduling" loop iterations in OpenMP to avoid work imbalance.
SFTPACK, a C code which implements the "slow" Fourier transform, intended as a teaching tool and comparison with the fast Fourier transform.
SGEFA_OPENMP, a C code which solves a linear system by Gaussian elimination, using OpenMP.
ZIGGURAT_OPENMP, a C code which demonstrates how the ZIGGURAT library can be used to generate random numbers in an OpenMP parallel program.