/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
/*
*
* (C) 2017 by Argonne National Laboratory.
* See COPYRIGHT in top-level directory.
*/
#include "mpiimpl.h"
/* Intercommunicator Reduce_scatter_block
*
* We first do an intercommunicator reduce to rank 0 on left group,
* then an intercommunicator reduce to rank 0 on right group, followed
* by local intracommunicator scattervs in each group.
*/
#undef FUNCNAME
#define FUNCNAME MPIR_Reduce_scatter_block_inter_remote_reduce_local_scatter
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Reduce_scatter_block_inter_remote_reduce_local_scatter(const void *sendbuf,
void *recvbuf,
int recvcount,
MPI_Datatype datatype,
MPI_Op op,
MPIR_Comm * comm_ptr,
MPIR_Errflag_t * errflag)
{
int rank, mpi_errno, root, local_size, total_count;
int mpi_errno_ret = MPI_SUCCESS;
MPI_Aint true_extent, true_lb = 0, extent;
void *tmp_buf = NULL;
MPIR_Comm *newcomm_ptr = NULL;
MPIR_CHKLMEM_DECL(1);
rank = comm_ptr->rank;
local_size = comm_ptr->local_size;
total_count = local_size * recvcount;
if (rank == 0) {
/* In each group, rank 0 allocates a temp. buffer for the
* reduce */
MPIR_Type_get_true_extent_impl(datatype, &true_lb, &true_extent);
MPIR_Datatype_get_extent_macro(datatype, extent);
MPIR_CHKLMEM_MALLOC(tmp_buf, void *, total_count * (MPL_MAX(extent, true_extent)),
mpi_errno, "tmp_buf", MPL_MEM_BUFFER);
/* adjust for potential negative lower bound in datatype */
tmp_buf = (void *) ((char *) tmp_buf - true_lb);
}
/* first do a reduce from right group to rank 0 in left group,
* then from left group to rank 0 in right group */
if (comm_ptr->is_low_group) {
/* reduce from right group to rank 0 */
root = (rank == 0) ? MPI_ROOT : MPI_PROC_NULL;
mpi_errno = MPIR_Reduce_inter_auto(sendbuf, tmp_buf, total_count, datatype, op,
root, comm_ptr, errflag);
if (mpi_errno) {
/* for communication errors, just record the error but continue */
*errflag =
MPIX_ERR_PROC_FAILED ==
MPIR_ERR_GET_CLASS(mpi_errno) ? MPIR_ERR_PROC_FAILED : MPIR_ERR_OTHER;
MPIR_ERR_SET(mpi_errno, *errflag, "**fail");
MPIR_ERR_ADD(mpi_errno_ret, mpi_errno);
}
/* reduce to rank 0 of right group */
root = 0;
mpi_errno = MPIR_Reduce_inter_auto(sendbuf, tmp_buf, total_count, datatype, op,
root, comm_ptr, errflag);
if (mpi_errno) {
/* for communication errors, just record the error but continue */
*errflag =
MPIX_ERR_PROC_FAILED ==
MPIR_ERR_GET_CLASS(mpi_errno) ? MPIR_ERR_PROC_FAILED : MPIR_ERR_OTHER;
MPIR_ERR_SET(mpi_errno, *errflag, "**fail");
MPIR_ERR_ADD(mpi_errno_ret, mpi_errno);
}
} else {
/* reduce to rank 0 of left group */
root = 0;
mpi_errno = MPIR_Reduce_inter_auto(sendbuf, tmp_buf, total_count, datatype, op,
root, comm_ptr, errflag);
if (mpi_errno) {
/* for communication errors, just record the error but continue */
*errflag =
MPIX_ERR_PROC_FAILED ==
MPIR_ERR_GET_CLASS(mpi_errno) ? MPIR_ERR_PROC_FAILED : MPIR_ERR_OTHER;
MPIR_ERR_SET(mpi_errno, *errflag, "**fail");
MPIR_ERR_ADD(mpi_errno_ret, mpi_errno);
}
/* reduce from right group to rank 0 */
root = (rank == 0) ? MPI_ROOT : MPI_PROC_NULL;
mpi_errno = MPIR_Reduce_inter_auto(sendbuf, tmp_buf, total_count, datatype, op,
root, comm_ptr, errflag);
if (mpi_errno) {
/* for communication errors, just record the error but continue */
*errflag =
MPIX_ERR_PROC_FAILED ==
MPIR_ERR_GET_CLASS(mpi_errno) ? MPIR_ERR_PROC_FAILED : MPIR_ERR_OTHER;
MPIR_ERR_SET(mpi_errno, *errflag, "**fail");
MPIR_ERR_ADD(mpi_errno_ret, mpi_errno);
}
}
/* Get the local intracommunicator */
if (!comm_ptr->local_comm)
MPII_Setup_intercomm_localcomm(comm_ptr);
newcomm_ptr = comm_ptr->local_comm;
mpi_errno = MPIR_Scatter(tmp_buf, recvcount, datatype, recvbuf,
recvcount, datatype, 0, newcomm_ptr, errflag);
if (mpi_errno) {
/* for communication errors, just record the error but continue */
*errflag =
MPIX_ERR_PROC_FAILED ==
MPIR_ERR_GET_CLASS(mpi_errno) ? MPIR_ERR_PROC_FAILED : MPIR_ERR_OTHER;
MPIR_ERR_SET(mpi_errno, *errflag, "**fail");
MPIR_ERR_ADD(mpi_errno_ret, mpi_errno);
}
fn_exit:
MPIR_CHKLMEM_FREEALL();
/* --BEGIN ERROR HANDLING-- */
if (mpi_errno_ret)
mpi_errno = mpi_errno_ret;
else if (*errflag != MPIR_ERR_NONE)
MPIR_ERR_SET(mpi_errno, *errflag, "**coll_fail");
/* --END ERROR HANDLING-- */
return mpi_errno;
fn_fail:
goto fn_exit;
}