Reduce.cpp

#include #include #include #include #include #include #include

#ifdef __cplusplus extern "C" { #endif void generateReduceData (int* arr, size_t n); #ifdef __cplusplus } #endif

int main (int argc, char* argv[]) { //forces openmp to create the threads beforehand #pragma omp parallel { int fd = open (argv[0], O_RDONLY); if (fd != -1) { close (fd); } else { std::cerr "

int n = atoi(argv[1]); int * arr = new int [n];

generateReduceData (arr, atoi(argv[1]));

//insert reduction code here delete[] arr;

return 0; }

1 Reduce Question: Write a program that compute the sum of an array in parallel using the OpenMP for loop construct. Measure the time computing the sum takes. Write the program so that you can control the length of the array, the number of thread and the scheduling policy; passed as parameters to main. Output the value of the reduction to stdout and the time taken to compute it to stderr. Use the template of reduce. cpp; note that the array to reduce is obtain by calling the provided generateReduceData function. Test it works with make test.reduce. Question: Run the code on mamba using make bench reduce. Plot speedup charts with make plot reduce. Does the plots make sense? Why