CSC/ECE 506 Spring 2015/37 mr

1. Example 1
2. Example 2

Parallelize the code below using loop distribution

for (i=0; i<n; i++) {

S1:  a[i] = b[i-1] * a[i+1];
S2:  b[i] = b[i] * 3;
S3:  c[i] = .2 * (c[i-1] * c[i]);
} 

After loop distribution

for(i=0; i < n; i++) 

S1: a[i] = b[i-1] * a[i+1];

for(i=0; i < n; i++) 

S3: c[i] = .2* c[i-1] * c[i];

for(i=0; i < n; i++) 

S2: b[i] = b[i] * 3; Now write the parallelized code in openMP using C++

1. pragma omp parallel shared(a,b,c)private(i){

#pragma omp sections nowait { #pragma omp section for(i=0; i < n; i++) a[i] = b[i-1] * a[i+1];

#pragma omp section for(i=0; i<n; i++) c[i] = .2* c[i-1]*c[i];

#pragma omp section for(i=0; i < n; i++) b[i] = b[i] * 3; }//end omp sections

} //end omp parallel