MPI_Reduce

--- Reduces values on all processes to a single value

Input Parameters

sendbuf: address of send buffer (choice)

count: number of elements in send buffer (integer)

datatype: data type of elements of send buffer (handle)

op: reduce operation (handle)

root: rank of root process (integer)

comm: communicator (handle)

Output Parameter

recvbuf: address of receive buffer (choice, significant only at root)

Algorithm

This implementation currently uses a simple tree algorithm.

Synopsis


#include "mpi.h"
int MPI_Reduce ( sendbuf, recvbuf, count, datatype, op, root, comm )
void             *sendbuf;
void             *recvbuf;
int               count;
MPI_Datatype      datatype;
MPI_Op            op;
int               root;
MPI_Comm          comm;

Location: reduce.c