openMP-test.rar_openMP-test_openmp_openmp test

#include<omp.h> static long num_steps=10000000; double step; #define NUM_THREADS 2 void main() { int ii; double x,pi,sum[NUM_THREADS]; step=1.0/num_steps; omp_set_num_threads(NUM_THREADS); //int i; #pragma omp parallel { double x; int id; int i; id=omp_get_thread_num(); for(i=id,sum[id]=0.0;i<num_steps;i=i+NUM_THREADS) { x=(i+0.5)*step; sum[id]+=4.0/(1.0+x*x); } printf("process %d-- sum[]=%f\n",id,sum[id]*step); } for(ii=0,pi=0.0;ii<NUM_THREADS;ii++) pi+=sum[ii]*step; printf("%f\n",pi); }