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rSCINTROPARALLEL/poisson.cc
5d0630ab7d66implementation/c++

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poisson.cc
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/* -------------------------------------------------------------------------- */
#include "simulation.hh"
/* -------------------------------------------------------------------------- */
#include <chrono>
#include <iostream>
#include <sstream>
#include <tuple>
/* -------------------------------------------------------------------------- */
#if defined(_MPI)
#include <mpi.h>
#endif
#if defined(_OPENMP)
#include <omp.h>
#endif
/* -------------------------------------------------------------------------- */
#define EPSILON 0.1
typedef std::chrono::high_resolution_clock clk;
typedef std::chrono::duration<double> second;
static void usage(const std::string & prog_name) {
std::cerr << prog_name << " <grid_size>" << std::endl;
exit(0);
}
int main(int argc, char * argv[]) {
int prank{0}, psize{1}, nthreads{1};
#if defined(_MPI)
int provided;
MPI_Init_thread(&argc, &argv, MPI_THREAD_MULTIPLE, &provided);
// assert(provided == MPI_THREAD_MULTIPLE);
MPI_Comm_rank(MPI_COMM_WORLD, &prank);
MPI_Comm_size(MPI_COMM_WORLD, &psize);
#endif
#if defined (_OPENMP)
nthreads = omp_get_max_threads();
#endif
if (argc != 2)
usage(argv[0]);
std::stringstream args(argv[1]);
int N;
args >> N;
if (args.fail())
usage(argv[0]);
std::unique_ptr<Simulation> simu;
#if defined(_MPI)
simu = std::make_unique<Simulation>(N, N, MPI_COMM_WORLD);
#else
simu = std::make_unique<Simulation>(N, N);
#endif
simu->set_initial_conditions();
simu->set_epsilon(EPSILON);
float l2;
int k;
auto start = clk::now();
std::tie(l2, k) = simu->compute();
auto end = clk::now();
second time = end - start;
auto min = simu->min();
auto max = simu->max();
if (prank == 0)
std::cout << "MPI: " << psize << " (" << simu->dims(0) << ", " << simu->dims(1) << ")\n"
<< "OMP: " << nthreads << "\n"
<< "Grid: " << N << "x" << N << "\n"
<< "Bound: " << "[ " << min << " : " << max << " ]" << "\n"
<< "Iter: " << k << "\n"
<< "Norm: " << std::scientific << l2 << "\n"
<< "Time: " << time.count() << "s" << "\n"
<< "Flops: " << simu->complexity()*k/time.count()/1e9 << " GFlops" << std::endl;
#if defined(_MPI)
simu.release(); // To force destruction of MPI related stuff
MPI_Finalize();
#endif
return 0;
}
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