mpi_ops.cpp

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#include "core/parallel/mpi_ops.hpp"
#include <cmath>
 
namespace num::mpi {
 
void init(int* argc, char*** argv) { MPI_Init(argc, argv); }
void finalize() { MPI_Finalize(); }
 
int rank(MPI_Comm comm) {
    int r; MPI_Comm_rank(comm, &r); return r;
}
 
int size(MPI_Comm comm) {
    int s; MPI_Comm_size(comm, &s); return s;
}
 
real dot(const Vector& x, const Vector& y, MPI_Comm comm) {
    real local = num::dot(x, y), global;
    MPI_Allreduce(&local, &global, 1, MPI_DOUBLE, MPI_SUM, comm);
    return global;
}
 
real norm(const Vector& x, MPI_Comm comm) {
    real local_sq = num::dot(x, x), global_sq;
    MPI_Allreduce(&local_sq, &global_sq, 1, MPI_DOUBLE, MPI_SUM, comm);
    return std::sqrt(global_sq);
}
 
void allreduce_sum(real* data, idx n, MPI_Comm comm) {
    MPI_Allreduce(MPI_IN_PLACE, data, static_cast<int>(n), MPI_DOUBLE, MPI_SUM, comm);
}
 
void broadcast(real* data, idx n, int root, MPI_Comm comm) {
    MPI_Bcast(data, static_cast<int>(n), MPI_DOUBLE, root, comm);
}
 
} // namespace num::mpi