MPI_Bcast(3)               (9/21/1994)               MPI_Bcast(3)



     NAME
          MPI_Bcast - Broadcasts a message from the process with rank
          "root" to all other processes of the group.


     INPUT/OUTPUT PARAMETER
          buffer
               - starting address of buffer (choice)
          count
               - number of entries in buffer (integer)
          datatype
               - data type of buffer (handle)
          root - rank of broadcast root (integer)
          comm - communicator (handle)


     ALGORITHM
          This function uses a tree-like algorithm to broadcast the
          message to blocks of processes.  A linear algorithm is then
          used to broadcast the message from the first process in a
          block to all other processes.  MPIR_BCAST_BLOCK_SIZE
          determines the size of blocks.  If this is set to 1, then
          this function is equivalent to using a pure tree algorithm.
          If it is set to the size of the group or greater, it is a
          pure linear algorithm.  The value should be adjusted to
          determine the most efficient value on different machines.


     SYNOPSIS
          #include "mpi.h"
          int MPI_Bcast ( buffer, count, datatype, root, comm )
          void             *buffer;
          int               count;
          MPI_Datatype      datatype;
          int               root;
          MPI_Comm          comm;



     LOCATION
           bcast.c














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