/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
/*
*
* (C) 2001 by Argonne National Laboratory.
* See COPYRIGHT in top-level directory.
*/
#include "mpiimpl.h"
/* -- Begin Profiling Symbol Block for routine MPI_Cart_shift */
#if defined(HAVE_PRAGMA_WEAK)
#pragma weak MPI_Cart_shift = PMPI_Cart_shift
#elif defined(HAVE_PRAGMA_HP_SEC_DEF)
#pragma _HP_SECONDARY_DEF PMPI_Cart_shift MPI_Cart_shift
#elif defined(HAVE_PRAGMA_CRI_DUP)
#pragma _CRI duplicate MPI_Cart_shift as PMPI_Cart_shift
#elif defined(HAVE_WEAK_ATTRIBUTE)
int MPI_Cart_shift(MPI_Comm comm, int direction, int disp, int *rank_source, int *rank_dest)
__attribute__ ((weak, alias("PMPI_Cart_shift")));
#endif
/* -- End Profiling Symbol Block */
/* Define MPICH_MPI_FROM_PMPI if weak symbols are not supported to build
the MPI routines */
#ifndef MPICH_MPI_FROM_PMPI
#undef MPI_Cart_shift
#define MPI_Cart_shift PMPI_Cart_shift
#undef FUNCNAME
#define FUNCNAME MPIR_Cart_shift_impl
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Cart_shift_impl(MPIR_Comm * comm_ptr, int direction, int disp, int *rank_source,
int *rank_dest)
{
int mpi_errno = MPI_SUCCESS;
MPIR_Topology *cart_ptr;
int i;
int pos[MAX_CART_DIM];
cart_ptr = MPIR_Topology_get(comm_ptr);
MPIR_ERR_CHKANDJUMP((!cart_ptr ||
cart_ptr->kind != MPI_CART), mpi_errno, MPI_ERR_TOPOLOGY, "**notcarttopo");
MPIR_ERR_CHKANDJUMP((cart_ptr->topo.cart.ndims == 0), mpi_errno, MPI_ERR_TOPOLOGY,
"**dimszero");
MPIR_ERR_CHKANDJUMP2((direction >= cart_ptr->topo.cart.ndims), mpi_errno, MPI_ERR_ARG,
"**dimsmany", "**dimsmany %d %d", cart_ptr->topo.cart.ndims, direction);
/* Check for the case of a 0 displacement */
if (disp == 0) {
*rank_source = *rank_dest = comm_ptr->rank;
} else {
/* To support advanced implementations that support MPI_Cart_create,
* we compute the new position and call PMPI_Cart_rank to get the
* source and destination. We could bypass that step if we know that
* the mapping is trivial. Copy the current position. */
for (i = 0; i < cart_ptr->topo.cart.ndims; i++) {
pos[i] = cart_ptr->topo.cart.position[i];
}
/* We must return MPI_PROC_NULL if shifted over the edge of a
* non-periodic mesh */
pos[direction] += disp;
if (!cart_ptr->topo.cart.periodic[direction] &&
(pos[direction] >= cart_ptr->topo.cart.dims[direction] || pos[direction] < 0)) {
*rank_dest = MPI_PROC_NULL;
} else {
MPIR_Cart_rank_impl(cart_ptr, pos, rank_dest);
}
pos[direction] = cart_ptr->topo.cart.position[direction] - disp;
if (!cart_ptr->topo.cart.periodic[direction] &&
(pos[direction] >= cart_ptr->topo.cart.dims[direction] || pos[direction] < 0)) {
*rank_source = MPI_PROC_NULL;
} else {
MPIR_Cart_rank_impl(cart_ptr, pos, rank_source);
}
}
fn_exit:
return mpi_errno;
fn_fail:
goto fn_exit;
}
#endif
#undef FUNCNAME
#define FUNCNAME MPI_Cart_shift
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
/*@
MPI_Cart_shift - Returns the shifted source and destination ranks, given a
shift direction and amount
Input Parameters:
+ comm - communicator with cartesian structure (handle)
. direction - coordinate dimension of shift (integer)
- disp - displacement (> 0: upwards shift, < 0: downwards shift) (integer)
Output Parameters:
+ rank_source - rank of source process (integer)
- rank_dest - rank of destination process (integer)
Notes:
The 'direction' argument is in the range '[0,n-1]' for an n-dimensional
Cartesian mesh.
.N SignalSafe
.N Fortran
.N Errors
.N MPI_SUCCESS
.N MPI_ERR_TOPOLOGY
.N MPI_ERR_COMM
.N MPI_ERR_ARG
@*/
int MPI_Cart_shift(MPI_Comm comm, int direction, int disp, int *rank_source, int *rank_dest)
{
int mpi_errno = MPI_SUCCESS;
MPIR_Comm *comm_ptr = NULL;
MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPI_CART_SHIFT);
MPIR_ERRTEST_INITIALIZED_ORDIE();
MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPI_CART_SHIFT);
/* Validate parameters, especially handles needing to be converted */
#ifdef HAVE_ERROR_CHECKING
{
MPID_BEGIN_ERROR_CHECKS;
{
MPIR_ERRTEST_COMM(comm, mpi_errno);
}
MPID_END_ERROR_CHECKS;
}
#endif
/* Convert MPI object handles to object pointers */
MPIR_Comm_get_ptr(comm, comm_ptr);
/* Validate parameters and objects (post conversion) */
#ifdef HAVE_ERROR_CHECKING
{
MPID_BEGIN_ERROR_CHECKS;
{
/* Validate comm_ptr */
MPIR_Comm_valid_ptr(comm_ptr, mpi_errno, TRUE);
if (mpi_errno)
goto fn_fail;
/* If comm_ptr is not valid, it will be reset to null */
MPIR_ERRTEST_ARGNULL(rank_source, "rank_source", mpi_errno);
MPIR_ERRTEST_ARGNULL(rank_dest, "rank_dest", mpi_errno);
MPIR_ERRTEST_ARGNEG(direction, "direction", mpi_errno);
/* Nothing in the standard indicates that a zero displacement
* is not valid, so we don't check for a zero shift */
}
MPID_END_ERROR_CHECKS;
}
#endif /* HAVE_ERROR_CHECKING */
/* ... body of routine ... */
mpi_errno = MPIR_Cart_shift_impl(comm_ptr, direction, disp, rank_source, rank_dest);
if (mpi_errno)
MPIR_ERR_POP(mpi_errno);
/* ... end of body of routine ... */
fn_exit:
MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPI_CART_SHIFT);
return mpi_errno;
fn_fail:
/* --BEGIN ERROR HANDLING-- */
#ifdef HAVE_ERROR_CHECKING
{
mpi_errno =
MPIR_Err_create_code(mpi_errno, MPIR_ERR_RECOVERABLE, FCNAME, __LINE__, MPI_ERR_OTHER,
"**mpi_cart_shift", "**mpi_cart_shift %C %d %d %p %p", comm,
direction, disp, rank_source, rank_dest);
}
#endif
mpi_errno = MPIR_Err_return_comm(comm_ptr, FCNAME, mpi_errno);
goto fn_exit;
/* --END ERROR HANDLING-- */
}