mpi_datatype_size.cpp

#include <iostream>
#include <vector>
#include <mpi.h>

#define DATASIZE(VariableName) std::cout << # VariableName << " " << get_datasize(VariableName) << std::endl;

int get_datasize(MPI_Datatype datatype)
{
   int datasize = 0;
   MPI_Type_size(datatype, &datasize);
   return datasize;
}

int main( int argc, char *argv[] )
{
   int size, rank;
   MPI_Init( &argc, &argv );
   MPI_Comm_size( MPI_COMM_WORLD, &size );
   MPI_Comm_rank( MPI_COMM_WORLD, &rank );

   DATASIZE(MPI_CHAR);
   DATASIZE(MPI_SHORT);
   DATASIZE(MPI_INT);
   DATASIZE(MPI_LONG);
   DATASIZE(MPI_LONG_LONG);
   DATASIZE(MPI_FLOAT);
   DATASIZE(MPI_DOUBLE);
   DATASIZE(MPI_LONG_DOUBLE);
   DATASIZE(MPI_UNSIGNED_CHAR);
   DATASIZE(MPI_UNSIGNED_SHORT);
   DATASIZE(MPI_UNSIGNED);
   DATASIZE(MPI_UNSIGNED_LONG);
   DATASIZE(MPI_UNSIGNED_LONG_LONG);
   DATASIZE(MPI_INT8_T);
   DATASIZE(MPI_INT16_T);
   DATASIZE(MPI_INT32_T);
   DATASIZE(MPI_INT64_T);
   DATASIZE(MPI_UINT8_T);
   DATASIZE(MPI_UINT16_T);
   DATASIZE(MPI_UINT32_T);
   DATASIZE(MPI_UINT64_T);
   DATASIZE(MPI_2INT);
   DATASIZE(MPI_SHORT_INT);
   DATASIZE(MPI_LONG_INT);
   DATASIZE(MPI_FLOAT_INT);
   DATASIZE(MPI_DOUBLE_INT);
   DATASIZE(MPI_LONG_DOUBLE_INT);

   MPI_Finalize();
   return 0;
 }