int MPIR_Cart_shift_impl(MPID_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 );
MPIU_ERR_CHKANDJUMP((!cart_ptr || cart_ptr->kind != MPI_CART), mpi_errno, MPI_ERR_TOPOLOGY, "**notcarttopo");
MPIU_ERR_CHKANDJUMP((cart_ptr->topo.cart.ndims == 0), mpi_errno, MPI_ERR_TOPOLOGY, "**dimszero");
MPIU_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;
}
/*@
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)
- displ - displacement (> 0: upwards shift, < 0: downwards shift) (integer)
Output Parameters:
+ source - rank of source process (integer)
- 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 displ, int *source,
int *dest)
{
int mpi_errno = MPI_SUCCESS;
MPID_Comm *comm_ptr = NULL;
MPIR_Topology *cart_ptr;
int i;
int pos[MAX_CART_DIM];
int rank;
MPID_MPI_STATE_DECL(MPID_STATE_MPI_CART_SHIFT);
MPIR_ERRTEST_INITIALIZED_ORDIE();
MPID_MPI_FUNC_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);
if (mpi_errno != MPI_SUCCESS) goto fn_fail;
}
MPID_END_ERROR_CHECKS;
}
# endif
/* Convert MPI object handles to object pointers */
MPID_Comm_get_ptr( comm, comm_ptr );
/* Validate parameters and objects (post conversion) */
# ifdef HAVE_ERROR_CHECKING
{
MPID_BEGIN_ERROR_CHECKS;
{
/* Validate comm_ptr */
MPID_Comm_valid_ptr( comm_ptr, mpi_errno );
/* If comm_ptr is not valid, it will be reset to null */
MPIR_ERRTEST_ARGNULL( source, "source", mpi_errno );
MPIR_ERRTEST_ARGNULL( dest, "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 */
if (mpi_errno) goto fn_fail;
}
MPID_END_ERROR_CHECKS;
}
# endif /* HAVE_ERROR_CHECKING */
/* ... body of routine ... */
cart_ptr = MPIR_Topology_get( comm_ptr );
MPIU_ERR_CHKANDJUMP((!cart_ptr || cart_ptr->kind != MPI_CART), mpi_errno, MPI_ERR_TOPOLOGY, "**notcarttopo");
MPIU_ERR_CHKANDJUMP((cart_ptr->topo.cart.ndims == 0), mpi_errno, MPI_ERR_TOPOLOGY, "**dimszero");
MPIU_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 */
rank = comm_ptr->rank;
if (displ == 0) {
*source = *dest = 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] += displ;
if (!cart_ptr->topo.cart.periodic[direction] &&
(pos[direction] >= cart_ptr->topo.cart.dims[direction] ||
pos[direction] < 0)) {
*dest = MPI_PROC_NULL;
}
else {
MPIR_Cart_rank_impl( cart_ptr, pos, dest );
}
pos[direction] = cart_ptr->topo.cart.position[direction] - displ;
if (!cart_ptr->topo.cart.periodic[direction] &&
(pos[direction] >= cart_ptr->topo.cart.dims[direction] ||
pos[direction] < 0)) {
*source = MPI_PROC_NULL;
}
else {
MPIR_Cart_rank_impl( cart_ptr, pos, source );
}
}
/* ... end of body of routine ... */
fn_exit:
MPID_MPI_FUNC_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, displ, source, dest);
}
# endif
mpi_errno = MPIR_Err_return_comm( comm_ptr, FCNAME, mpi_errno );
goto fn_exit;
/* --END ERROR HANDLING-- */
}
/*@
MPI_Cart_rank - Determines process rank in communicator given Cartesian
location
Input Parameters:
+ comm - communicator with cartesian structure (handle)
- coords - integer array (of size 'ndims', the number of dimensions of
the Cartesian topology associated with 'comm') specifying the cartesian
coordinates of a process
Output Parameters:
. rank - rank of specified process (integer)
Notes:
Out-of-range coordinates are erroneous for non-periodic dimensions.
Versions of MPICH before 1.2.2 returned 'MPI_PROC_NULL' for the rank in this
case.
.N SignalSafe
.N Fortran
.N Errors
.N MPI_SUCCESS
.N MPI_ERR_TOPOLOGY
.N MPI_ERR_RANK
.N MPI_ERR_ARG
@*/
int MPI_Cart_rank(MPI_Comm comm, const int coords[], int *rank)
{
int mpi_errno = MPI_SUCCESS;
MPIR_Comm *comm_ptr = NULL;
MPIR_Topology *cart_ptr;
MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPI_CART_RANK);
MPIR_ERRTEST_INITIALIZED_ORDIE();
MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPI_CART_RANK);
/* 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 );
# 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,"rank",mpi_errno);
}
MPID_END_ERROR_CHECKS;
}
# endif /* HAVE_ERROR_CHECKING */
cart_ptr = MPIR_Topology_get( comm_ptr );
MPIR_ERR_CHKANDJUMP((!cart_ptr || cart_ptr->kind != MPI_CART), mpi_errno, MPI_ERR_TOPOLOGY, "**notcarttopo");
/* Validate coordinates */
# ifdef HAVE_ERROR_CHECKING
{
int i, ndims, coord;
MPID_BEGIN_ERROR_CHECKS;
{
ndims = cart_ptr->topo.cart.ndims;
if (ndims != 0) {
MPIR_ERRTEST_ARGNULL(coords,"coords",mpi_errno);
}
for (i=0; i<ndims; i++) {
if (!cart_ptr->topo.cart.periodic[i]) {
coord = coords[i];
MPIR_ERR_CHKANDJUMP3(
(coord < 0 || coord >= cart_ptr->topo.cart.dims[i] ), mpi_errno, MPI_ERR_ARG, "**cartcoordinvalid",
"**cartcoordinvalid %d %d %d",i, coords[i], cart_ptr->topo.cart.dims[i]-1 );
}
}
}
MPID_END_ERROR_CHECKS;
}
# endif /* HAVE_ERROR_CHECKING */
/* ... body of routine ... */
MPIR_Cart_rank_impl(cart_ptr, coords, rank);
/* ... end of body of routine ... */
fn_exit:
MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPI_CART_RANK);
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_rank",
"**mpi_cart_rank %C %p %p", comm, coords, rank);
}
# endif
mpi_errno = MPIR_Err_return_comm( comm_ptr, FCNAME, mpi_errno );
goto fn_exit;
/* --END ERROR HANDLING-- */
}
