Is it possible to do a reduction on an array with openmp?

Question

Does OpenMP natively support reduction of a variable that represents an array?

This would work something like the following...

float* a = (float*) c         


        

Answer 1

OpenMP can perform this operation as of OpenMP 4.5 and GCC 6.3 (and possibly lower) supports it. An example program looks as follows:

#include 
#include 

int main(){
  std::vector vec;

  #pragma omp declare reduction (merge : std::vector : omp_out.insert(omp_out.end(), omp_in.begin(), omp_in.end()))

  #pragma omp parallel for default(none) schedule(static) reduction(merge: vec)
  for(int i=0;i<100;i++)
    vec.push_back(i);

  for(const auto x: vec)
    std::cout<

Note that omp_out and omp_in are special variables and that the type of the declare reduction must match the vector you are planning to reduce on.