Count Parameter

• Recall that MPI_Send, MPI_Recv, MPI_Bcast and MPI_Reduce all have a count parameter

• This allows us to group data of the same basic type as long as the data items are stored in contiguous memory

• C and FORTRAN guarantee that array elements are stored in such a fashion

• Hence we can use address+count parameters to send any contiguous chunk of an array

• Suppose we want to send the second half of an array from process 0 to process 1?

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