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openmpi/ompi/mpi/c/reduce_scatter.c
Jeff Squyres 7bdfe6557b - Update the checks in REDUCE, ALLREDUCE, SCAN, EXSCAN, and
REDUCE_SCATTER to more thoroughly check the datatype/op combination
  to see if it's valid or not.  If it's not, print a meaningful error
  message rather than "Invalid MPI_Op" indicating what specifically
  was wrong (therefore hopefully helping users track down where in the
  code the problem is, and/or telling us that there's a reduction
  operation combo that we don't support that we should)
- The check for whether a datatype is intrinsic needed to be updated
  -- it's not sufficient to check that dtype->id < DT_MAX_PREDEFINED;
  you really need to check the PREDEFINED flag on the datatype.
  Thanks to George for this fix (only intrinsics have a meaningful
  value in dtype->id).

This commit was SVN r7923.
2005-10-28 16:47:32 +00:00

98 строки
3.1 KiB
C

/*
* Copyright (c) 2004-2005 The Trustees of Indiana University.
* All rights reserved.
* Copyright (c) 2004-2005 The Trustees of the University of Tennessee.
* All rights reserved.
* Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
* University of Stuttgart. All rights reserved.
* Copyright (c) 2004-2005 The Regents of the University of California.
* All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include <stdio.h>
#include "mpi/c/bindings.h"
#include "ompi/datatype/datatype.h"
#include "ompi/op/op.h"
#if OMPI_HAVE_WEAK_SYMBOLS && OMPI_PROFILING_DEFINES
#pragma weak MPI_Reduce_scatter = PMPI_Reduce_scatter
#endif
#if OMPI_PROFILING_DEFINES
#include "mpi/c/profile/defines.h"
#endif
static const char FUNC_NAME[] = "MPI_Reduce_scatter";
int MPI_Reduce_scatter(void *sendbuf, void *recvbuf, int *recvcounts,
MPI_Datatype datatype, MPI_Op op, MPI_Comm comm)
{
int i, err, size, count;
if (MPI_PARAM_CHECK) {
char *msg;
err = MPI_SUCCESS;
OMPI_ERR_INIT_FINALIZE(FUNC_NAME);
if (ompi_comm_invalid(comm)) {
return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_COMM,
FUNC_NAME);
}
/* Unrooted operation; same checks for all ranks on both
intracommunicators and intercommunicators */
else if (MPI_OP_NULL == op) {
err = MPI_ERR_OP;
} else if (!ompi_op_is_valid(op, datatype, &msg, FUNC_NAME)) {
int ret = OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_OP, msg);
free(msg);
return ret;
} else if (NULL == recvcounts) {
err = MPI_ERR_COUNT;
} else if (MPI_IN_PLACE == recvbuf) {
err = MPI_ERR_ARG;
}
OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);
/* We always define the remote group to be the same as the
local group in the case of an intracommunicator, so it's
safe to get the size of the remote group here for both
intra- and intercommunicators */
size = ompi_comm_size(comm);
for (i = 0; i < size; ++i) {
OMPI_CHECK_DATATYPE_FOR_SEND(err, datatype, recvcounts[i]);
OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);
}
}
/* MPI-1, p114, says that each process must supply at least one
element. But at least the Pallas benchmarks call MPI_REDUCE
with a count of 0. So be sure to handle it. Grrr... */
size = ompi_comm_size(comm);
for (count = i = 0; i < size; ++i) {
if (0 == recvcounts[i]) {
++count;
}
}
if (size == count) {
return MPI_SUCCESS;
}
/* Invoke the coll component to perform the back-end operation */
OBJ_RETAIN(op);
err = comm->c_coll.coll_reduce_scatter(sendbuf, recvbuf, recvcounts,
datatype, op, comm);
OBJ_RELEASE(op);
OMPI_ERRHANDLER_RETURN(err, comm, err, FUNC_NAME);
}