root/ompi/mca/topo/base/topo_base_cart_rank.c

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DEFINITIONS

This source file includes following definitions.
  1. mca_topo_base_cart_rank

   1 /*
   2  * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
   3  *                         University Research and Technology
   4  *                         Corporation.  All rights reserved.
   5  * Copyright (c) 2004-2013 The University of Tennessee and The University
   6  *                         of Tennessee Research Foundation.  All rights
   7  *                         reserved.
   8  * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
   9  *                         University of Stuttgart.  All rights reserved.
  10  * Copyright (c) 2004-2005 The Regents of the University of California.
  11  *                         All rights reserved.
  12  * Copyright (c) 2008      Cisco Systems, Inc.  All rights reserved.
  13  * Copyright (c) 2012-2013 Inria.  All rights reserved.
  14  * Copyright (c) 2015      Research Organization for Information Science
  15  *                         and Technology (RIST). All rights reserved.
  16  * $COPYRIGHT$
  17  *
  18  * Additional copyrights may follow
  19  *
  20  * $HEADER$
  21  */
  22 
  23 #include "ompi_config.h"
  24 #include "ompi/mca/topo/base/base.h"
  25 #include "ompi/communicator/communicator.h"
  26 
  27 /*
  28  * function - Determines process rank in communicator given Cartesian
  29  *                 location
  30  *
  31  * @param comm communicator with cartesian structure (handle)
  32  * @param coords integer array (of size  'ndims') specifying the cartesian
  33  *               coordinates of a process
  34  * @param rank rank of specified process (integer)
  35  *
  36  * @retval MPI_SUCCESS
  37  * @retval MPI_ERR_COMM
  38  * @retval MPI_ERR_TOPOLOGY
  39  * @retval MPI_ERR_ARG
  40  */
  41 
  42 int mca_topo_base_cart_rank(ompi_communicator_t* comm,
  43                             const int *coords,
  44                             int *rank)
  45 {
  46    int prank;
  47    int dim;
  48    int ord;
  49    int factor;
  50    int i;
  51    int *d;
  52 
  53    /*
  54     * Loop over coordinates computing the rank.
  55     */
  56     factor = 1;
  57     prank = 0;
  58 
  59     i = comm->c_topo->mtc.cart->ndims - 1;
  60     d = comm->c_topo->mtc.cart->dims + i;
  61 
  62    for (; i >= 0; --i, --d) {
  63        dim = *d;
  64        ord = coords[i];
  65        /* Per MPI-2.1 7.5.4 (description of MPI_CART_RANK), if the
  66           dimension is periodic and the coordinate is outside of 0 <=
  67           coord(i) < dim, then normalize it.  If the dimension is not
  68           periodic, it's an error. */
  69        if ((ord < 0) || (ord >= dim)) {
  70            ord %= dim;
  71            if (ord < 0) {
  72                ord += dim;
  73            }
  74        }
  75        prank += factor * ord;
  76        factor *= dim;
  77     }
  78     *rank = prank;
  79 
  80     return(MPI_SUCCESS);
  81 }

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