MPI_Alltoall(3)

NAME
     MPI_Alltoall - Sends data from all processes to all processes

SYNOPSIS
     C:

          #include <mpi.h>

          int MPI_Alltoall( sendbuf, sendcount, sendtype,
                            recvbuf, recvcnt, recvtype, comm )
          void             *sendbuf;
          int               sendcount;
          MPI_Datatype      sendtype;
          void             *recvbuf;
          int               recvcnt;
          MPI_Datatype      recvtype;
          MPI_Comm          comm;


     C++:

          #include <mpi.h>

          void Intracomm::Alltoall(
          const void*       sendbuf,
          int               sendcount,
          const Datatype&   sendtype,
          void*             recvbuf,
          int               recvcount,
          const Datatype&   recvtype) const


     Fortran:

          INCLUDE "mpif.h" (or USE MPI)

          <type> SENDBUF(*), RECVBUF(*)
          INTEGER sendcount, sendtype, recvcount,
          recvtype), comm, ierror

          CALL MPI_ALLTOALL(sendbuf, sendcount, sendtype,
          recvbuf, recvcount, recvtype), comm,
          ierror)


STANDARDS
     This release implements the MPI 1.2 standard, as documented by the MPI
     Forum in the spring 1997 release of MPI:  A Message Passing Interface
     Standard.
DESCRIPTION
     The MPI_Alltoall routine sends data from all processes to all processes.
     This routine accepts the following parameters:

     sendbuf   Specifies the starting address of the send buffer (choice)

     sendcount Specifies the number of elements in the send buffer (integer)

     sendtype  Specifies the data type of the send buffer elements (handle)

     recvcnt   Specifies the number of elements received from any process
               (integer)

     recvtype  Specifies the data type of the receive buffer elements (handle)

     comm      Specifies the communicator (handle)

     recvbuf   Returns the address of the receive buffer (choice)

     ierror    Specifies the return code value for successful completion,
               which is in MPI_SUCCESS.  MPI_SUCCESS is defined in the mpif.h
               file.