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openmpi/ompi/mca/topo/base/topo_base_cart_rank.c
Jeff Squyres 9a98423bbc [Re-]Fix #1463 with a little thing that I like to call "the right
way".

Don't modify coords in the top-level API function because coords is an
IN variable.  Instead, as Nysal noted, the real cause of the problem
was a missing ! down in topo_base_cart_rank.c.  Put a comment down in
topo_base_cart_rank.c explaining what's going on so that the code is
not so cryptic.

Refs trac:1363.

This commit was SVN r19487.

The following Trac tickets were found above:
  Ticket 1363 --> https://svn.open-mpi.org/trac/ompi/ticket/1363
2008-09-03 08:24:27 +00:00

86 строки
2.5 KiB
C

/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2005 The University of Tennessee and The University
* of Tennessee Research Foundation. 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 (c) 2008 Cisco Systems, Inc. All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include "ompi/mca/topo/base/base.h"
#include "ompi/communicator/communicator.h"
#include "ompi/mca/topo/topo.h"
/*
* function - Determines process rank in communicator given Cartesian
* location
*
* @param comm communicator with cartesian structure (handle)
* @param coords integer array (of size 'ndims') specifying the cartesian
* coordinates of a process
* @param rank rank of specified process (integer)
*
* @retval MPI_SUCCESS
* @retval MPI_ERR_COMM
* @retval MPI_ERR_TOPOLOGY
* @retval MPI_ERR_ARG
*/
int mca_topo_base_cart_rank (MPI_Comm comm,
int *coords,
int *rank){
int prank;
int dim;
int ord;
int factor;
int i;
int *d;
int *c;
int *p;
/*
* Loop over coordinates computing the rank.
*/
factor = 1;
prank = 0;
i = comm->c_topo_comm->mtc_ndims_or_nnodes - 1;
d = comm->c_topo_comm->mtc_dims_or_index + i;
p = comm->c_topo_comm->mtc_periods_or_edges + i;
c = coords + i;
for (; i >= 0; --i, --c, --d, --p) {
dim = *d;
ord = *c;
/* Per MPI-2.1 7.5.4 (description of MPI_CART_RANK), if the
dimension is periodic and the coordinate is outside of 0 <=
coord(i) < dim, then normalize it. If the dimension is not
periodic, it's an error. */
if ((ord < 0) || (ord >= dim)) {
if (!*p) {
return MPI_ERR_ARG;
}
ord %= dim;
if (ord < 0) {
ord += dim;
}
}
prank += factor * ord;
factor *= dim;
}
*rank = prank;
return(MPI_SUCCESS);
}