lammps-sys 0.6.0

#include<Kokkos_Core.hpp>
#include<impl/Kokkos_Timer.hpp>
#include<Kokkos_Random.hpp>

template<class Scalar>
double test_atomic(int L, int N, int M,int K,int R,Kokkos::View<const int*> offsets) {
  Kokkos::View<Scalar*> output("Output",N);
  Kokkos::Impl::Timer timer;

  for(int r = 0; r<R; r++)
  Kokkos::parallel_for(L, KOKKOS_LAMBDA (const int&i) {
    Scalar s = 2;
    for(int m=0;m<M;m++) {
      for(int k=0;k<K;k++)
        s=s*s+s;
      const int idx = (i+offsets(i,m))%N;
      Kokkos::atomic_add(&output(idx),s);
    }
  }); 
  Kokkos::fence();
  double time = timer.seconds();
 
  return time;
}

template<class Scalar>
double test_no_atomic(int L, int N, int M,int K,int R,Kokkos::View<const int*> offsets) {
  Kokkos::View<Scalar*> output("Output",N);
  Kokkos::Impl::Timer timer;
  for(int r = 0; r<R; r++)
  Kokkos::parallel_for(L, KOKKOS_LAMBDA (const int&i) {
    Scalar s = 2;
    for(int m=0;m<M;m++) {
      for(int k=0;k<K;k++)
        s=s*s+s;
      const int idx = (i+offsets(i,m))%N;
      output(idx) += s;
    }
  });
  Kokkos::fence();
  double time =  timer.seconds();
  return time;
}

int main(int argc, char* argv[]) {
  Kokkos::initialize(argc,argv);
{
  if(argc<8) {
    printf("Arguments: L N M D K R T\n");
    printf("  L:   Number of iterations to run\n");
    printf("  N:   Length of array to do atomics into\n");
    printf("  M:   Number of atomics per iteration to do\n");
    printf("  D:   Distance from index i to do atomics into (randomly)\n");
    printf("  K:   Number of FMAD per atomic\n");
    printf("  R:   Number of repeats of the experiments\n");
    printf("  T:   Type of atomic\n");
    printf("       1 - int\n");
    printf("       2 - long\n");
    printf("       3 - float\n");
    printf("       4 - double\n");
    printf("       5 - complex<double>\n");
    printf("Example Input GPU:\n");
    printf("  Histogram : 1000000 1000 1 1000 1 10 1\n");
    printf("  MD Force : 100000 100000 100 1000 20 10 4\n");
    printf("  Matrix Assembly : 100000 1000000 50 1000 20 10 4\n");
    Kokkos::finalize();
    return 0;
  }


  int L = atoi(argv[1]);
  int N = atoi(argv[2]);
  int M = atoi(argv[3]);
  int D = atoi(argv[4]); 
  int K = atoi(argv[5]);
  int R = atoi(argv[6]); 
  int type = atoi(argv[7]);
 
  Kokkos::View<int*> offsets("Offsets",L,M);
  Kokkos::Random_XorShift64_Pool<> pool(12371);
  Kokkos::fill_random(offsets,pool,D);
  double time = 0;
  if(type==1)
    time  = test_atomic<int>(L,N,M,K,R,offsets);
  if(type==2)
    time = test_atomic<long>(L,N,M,K,R,offsets);
  if(type==3)
    time = test_atomic<float>(L,N,M,K,R,offsets);
  if(type==4)
    time = test_atomic<double>(L,N,M,K,R,offsets);
  if(type==5)
    time = test_atomic<Kokkos::complex<double> >(L,N,M,K,R,offsets);

  double time2 = 1;
  if(type==1)
    time2 = test_no_atomic<int>(L,N,M,K,R,offsets);
  if(type==2)
    time2 = test_no_atomic<long>(L,N,M,K,R,offsets);
  if(type==3)
    time2 = test_no_atomic<float>(L,N,M,K,R,offsets);
  if(type==4)
    time2 = test_no_atomic<double>(L,N,M,K,R,offsets);
  if(type==5)
    time2 = test_no_atomic<Kokkos::complex<double> >(L,N,M,K,R,offsets);

  int size = 0;
  if(type==1) size = sizeof(int);
  if(type==2) size = sizeof(long);
  if(type==3) size = sizeof(float);
  if(type==4) size = sizeof(double);
  if(type==5) size = sizeof(Kokkos::complex<double>);

  printf("%i\n",size);
  printf("Time: %s %i %i %i %i %i %i (t_atomic: %e t_nonatomic: %e ratio: %lf )( GUpdates/s: %lf GB/s: %lf )\n",
    (type==1)?"int": (
    (type==2)?"long": (
    (type==3)?"float": (
    (type==4)?"double":"complex"))),
    L,N,M,D,K,R,time,time2,time/time2,
    1.e-9*L*R*M/time, 1.0*L*R*M*2*size/time/1024/1024/1024);
}
  Kokkos::finalize();
}