openmp和mpi的综合使用

openmp和mpi的综合使用

#include "mpi.h"
#include "omp.h"
#include <math.h>
#include<stdio.h>
#define N 1000000000

int main(int argc, char* argv[]) {
	int rank, nproc;
	int i, low, up;
	double local = 0.0, pi, w, temp;

	MPI_Status  status;
	MPI_Init(&argc, &argv);
	MPI_Comm_size(MPI_COMM_WORLD, &nproc);
	MPI_Comm_rank(MPI_COMM_WORLD, &rank);

	w = 1.0 / N;
	low = rank * (N / nproc);
	up = low + N / nproc - 1;

#pragma omp parallel for reduction(+:local) private(temp,i)
	for (i = low; i <= up; i++)
	{
		temp = (i + 0.5) * w;
		local = local + 4.0 / (1.0 + temp * temp);
	}
	MPI_Reduce(&local, &pi, 1, MPI_DOUBLE, MPI_SUM, 0, MPI_COMM_WORLD);
	if (rank == 0)
		printf("pi = %.20f\n", pi * w);

	MPI_Finalize();
}