int MPIR_Group_incl_impl(MPID_Group *group_ptr, int n, const int ranks[], MPID_Group **new_group_ptr)
{
int mpi_errno = MPI_SUCCESS;
int i;
MPID_MPI_STATE_DECL(MPID_STATE_MPIR_GROUP_INCL_IMPL);
MPID_MPI_FUNC_ENTER(MPID_STATE_MPIR_GROUP_INCL_IMPL);
if (n == 0) {
*new_group_ptr = MPID_Group_empty;
goto fn_exit;
}
/* Allocate a new group and lrank_to_lpid array */
mpi_errno = MPIR_Group_create( n, new_group_ptr );
if (mpi_errno) goto fn_fail;
(*new_group_ptr)->rank = MPI_UNDEFINED;
for (i = 0; i < n; i++) {
(*new_group_ptr)->lrank_to_lpid[i].lrank = i;
(*new_group_ptr)->lrank_to_lpid[i].lpid = group_ptr->lrank_to_lpid[ranks[i]].lpid;
if (ranks[i] == group_ptr->rank)
(*new_group_ptr)->rank = i;
}
(*new_group_ptr)->size = n;
(*new_group_ptr)->idx_of_first_lpid = -1;
/* TODO calculate is_local_dense_monotonic */
fn_exit:
MPID_MPI_FUNC_EXIT(MPID_STATE_MPIR_GROUP_INCL_IMPL);
return mpi_errno;
fn_fail:
goto fn_exit;
}
int MPIR_Comm_group_impl(MPID_Comm *comm_ptr, MPID_Group **group_ptr)
{
int mpi_errno = MPI_SUCCESS;
MPID_VCR *local_vcr;
int i, lpid, n;
int comm_world_size = MPIR_Process.comm_world->local_size;
MPID_MPI_STATE_DECL(MPID_STATE_MPIR_COMM_GROUP_IMPL);
MPID_MPI_FUNC_ENTER(MPID_STATE_MPIR_COMM_GROUP_IMPL);
/* Create a group if necessary and populate it with the
local process ids */
if (!comm_ptr->local_group) {
n = comm_ptr->local_size;
mpi_errno = MPIR_Group_create( n, group_ptr );
if (mpi_errno) MPIU_ERR_POP(mpi_errno);
/* Make sure that we get the correct group */
if (comm_ptr->comm_kind == MPID_INTERCOMM) {
local_vcr = comm_ptr->local_vcr;
}
else
local_vcr = comm_ptr->vcr;
(*group_ptr)->is_local_dense_monotonic = TRUE;
for (i=0; i<n; i++) {
(void) MPID_VCR_Get_lpid( local_vcr[i], &lpid );
(*group_ptr)->lrank_to_lpid[i].lrank = i;
(*group_ptr)->lrank_to_lpid[i].lpid = lpid;
if (lpid > comm_world_size ||
(i > 0 && (*group_ptr)->lrank_to_lpid[i-1].lpid != (lpid-1)))
{
(*group_ptr)->is_local_dense_monotonic = FALSE;
}
}
(*group_ptr)->size = n;
(*group_ptr)->rank = comm_ptr->rank;
(*group_ptr)->idx_of_first_lpid = -1;
comm_ptr->local_group = *group_ptr;
} else {
*group_ptr = comm_ptr->local_group;
}
/* FIXME : Add a sanity check that the size of the group is the same as
the size of the communicator. This helps catch corrupted
communicators */
MPIR_Group_add_ref( comm_ptr->local_group );
fn_exit:
MPID_MPI_FUNC_EXIT(MPID_STATE_MPIR_COMM_GROUP_IMPL);
return mpi_errno;
fn_fail:
goto fn_exit;
}
int MPIR_Group_excl_impl(MPID_Group *group_ptr, int n, const int ranks[], MPID_Group **new_group_ptr)
{
int mpi_errno = MPI_SUCCESS;
int size, i, newi;
MPID_MPI_STATE_DECL(MPID_STATE_MPIR_GROUP_EXCL_IMPL);
MPID_MPI_FUNC_ENTER(MPID_STATE_MPIR_GROUP_EXCL_IMPL);
size = group_ptr->size;
/* Allocate a new group and lrank_to_lpid array */
mpi_errno = MPIR_Group_create( size - n, new_group_ptr );
if (mpi_errno) MPIR_ERR_POP(mpi_errno);
(*new_group_ptr)->rank = MPI_UNDEFINED;
/* Use flag fields to mark the members to *exclude* . */
for (i = 0; i < size; i++) {
group_ptr->lrank_to_lpid[i].flag = 0;
}
for (i = 0; i < n; i++) {
group_ptr->lrank_to_lpid[ranks[i]].flag = 1;
}
newi = 0;
for (i = 0; i < size; i++) {
if (group_ptr->lrank_to_lpid[i].flag == 0) {
(*new_group_ptr)->lrank_to_lpid[newi].lpid = group_ptr->lrank_to_lpid[i].lpid;
if (group_ptr->rank == i)
(*new_group_ptr)->rank = newi;
newi++;
}
}
(*new_group_ptr)->size = size - n;
(*new_group_ptr)->idx_of_first_lpid = -1;
/* TODO calculate is_local_dense_monotonic */
fn_exit:
MPID_MPI_FUNC_EXIT(MPID_STATE_MPIR_GROUP_EXCL_IMPL);
return mpi_errno;
fn_fail:
goto fn_exit;
}
int MPIR_Comm_remote_group_impl(MPID_Comm *comm_ptr, MPID_Group **group_ptr)
{
int mpi_errno = MPI_SUCCESS;
int i, lpid, n;
MPID_MPI_STATE_DECL(MPID_STATE_MPIR_COMM_REMOTE_GROUP_IMPL);
MPID_MPI_FUNC_ENTER(MPID_STATE_MPIR_COMM_REMOTE_GROUP_IMPL);
/* Create a group and populate it with the local process ids */
if (!comm_ptr->remote_group) {
n = comm_ptr->remote_size;
mpi_errno = MPIR_Group_create( n, group_ptr );
if (mpi_errno) MPIU_ERR_POP(mpi_errno);
for (i=0; i<n; i++) {
(*group_ptr)->lrank_to_lpid[i].lrank = i;
(void) MPID_VCR_Get_lpid( comm_ptr->vcr[i], &lpid );
(*group_ptr)->lrank_to_lpid[i].lpid = lpid;
/* TODO calculate is_local_dense_monotonic */
}
(*group_ptr)->size = n;
(*group_ptr)->rank = MPI_UNDEFINED;
(*group_ptr)->idx_of_first_lpid = -1;
comm_ptr->remote_group = *group_ptr;
} else {
*group_ptr = comm_ptr->remote_group;
}
MPIR_Group_add_ref( comm_ptr->remote_group );
fn_exit:
MPID_MPI_FUNC_EXIT(MPID_STATE_MPIR_COMM_REMOTE_GROUP_IMPL);
return mpi_errno;
fn_fail:
goto fn_exit;
}
int MPIR_Group_intersection_impl(MPIR_Group *group_ptr1, MPIR_Group *group_ptr2, MPIR_Group **new_group_ptr)
{
int mpi_errno = MPI_SUCCESS;
int size1, i, k, g1_idx, g2_idx, l1_pid, l2_pid, nnew;
MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPIR_GROUP_INTERSECTION_IMPL);
MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPIR_GROUP_INTERSECTION_IMPL);
/* Return a group consisting of the members of group1 that are
in group2 */
size1 = group_ptr1->size;
/* Insure that the lpid lists are setup */
MPIR_Group_setup_lpid_pairs( group_ptr1, group_ptr2 );
for (i = 0; i < size1; i++) {
group_ptr1->lrank_to_lpid[i].flag = 0;
}
g1_idx = group_ptr1->idx_of_first_lpid;
g2_idx = group_ptr2->idx_of_first_lpid;
nnew = 0;
while (g1_idx >= 0 && g2_idx >= 0) {
l1_pid = group_ptr1->lrank_to_lpid[g1_idx].lpid;
l2_pid = group_ptr2->lrank_to_lpid[g2_idx].lpid;
if (l1_pid < l2_pid) {
g1_idx = group_ptr1->lrank_to_lpid[g1_idx].next_lpid;
}
else if (l1_pid > l2_pid) {
g2_idx = group_ptr2->lrank_to_lpid[g2_idx].next_lpid;
}
else {
/* Equal */
group_ptr1->lrank_to_lpid[g1_idx].flag = 1;
g1_idx = group_ptr1->lrank_to_lpid[g1_idx].next_lpid;
g2_idx = group_ptr2->lrank_to_lpid[g2_idx].next_lpid;
nnew ++;
}
}
/* Create the group. Handle the trivial case first */
if (nnew == 0) {
*new_group_ptr = MPIR_Group_empty;
goto fn_exit;
}
mpi_errno = MPIR_Group_create( nnew, new_group_ptr );
if (mpi_errno) MPIR_ERR_POP(mpi_errno);
(*new_group_ptr)->rank = MPI_UNDEFINED;
(*new_group_ptr)->is_local_dense_monotonic = TRUE;
k = 0;
for (i = 0; i < size1; i++) {
if (group_ptr1->lrank_to_lpid[i].flag) {
int lpid = group_ptr1->lrank_to_lpid[i].lpid;
(*new_group_ptr)->lrank_to_lpid[k].lpid = lpid;
if (i == group_ptr1->rank)
(*new_group_ptr)->rank = k;
if (lpid > MPIR_Process.comm_world->local_size ||
(k > 0 && (*new_group_ptr)->lrank_to_lpid[k-1].lpid != (lpid-1))) {
(*new_group_ptr)->is_local_dense_monotonic = FALSE;
}
k++;
}
}
fn_exit:
MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPIR_GROUP_INTERSECTION_IMPL);
return mpi_errno;
fn_fail:
goto fn_exit;
}
int MPIR_Group_range_incl_impl(MPID_Group *group_ptr, int n, int ranges[][3], MPID_Group **new_group_ptr)
{
int mpi_errno = MPI_SUCCESS;
int first, last, stride, nnew, i, j, k;
MPID_MPI_STATE_DECL(MPID_STATE_MPIR_GROUP_RANGE_INCL_IMPL);
MPID_MPI_FUNC_ENTER(MPID_STATE_MPIR_GROUP_RANGE_INCL_IMPL);
/* Compute size, assuming that included ranks are valid (and distinct) */
nnew = 0;
for (i=0; i<n; i++) {
first = ranges[i][0]; last = ranges[i][1]; stride = ranges[i][2];
/* works for stride of either sign. Error checking above
has already guaranteed stride != 0 */
nnew += 1 + (last - first) / stride;
}
if (nnew == 0) {
*new_group_ptr = MPID_Group_empty;
goto fn_exit;
}
/* Allocate a new group and lrank_to_lpid array */
mpi_errno = MPIR_Group_create( nnew, new_group_ptr );
if (mpi_errno) goto fn_fail;
(*new_group_ptr)->rank = MPI_UNDEFINED;
/* Group members taken in order specified by the range array */
/* This could be integrated with the error checking, but since this
is a low-usage routine, we haven't taken that optimization */
k = 0;
for (i=0; i<n; i++) {
first = ranges[i][0]; last = ranges[i][1]; stride = ranges[i][2];
if (stride > 0) {
for (j=first; j<=last; j += stride) {
(*new_group_ptr)->lrank_to_lpid[k].lpid =
group_ptr->lrank_to_lpid[j].lpid;
if (j == group_ptr->rank)
(*new_group_ptr)->rank = k;
k++;
}
}
else {
for (j=first; j>=last; j += stride) {
(*new_group_ptr)->lrank_to_lpid[k].lpid =
group_ptr->lrank_to_lpid[j].lpid;
if (j == group_ptr->rank)
(*new_group_ptr)->rank = k;
k++;
}
}
}
/* TODO calculate is_local_dense_monotonic */
fn_exit:
MPID_MPI_FUNC_EXIT(MPID_STATE_MPIR_GROUP_RANGE_INCL_IMPL);
return mpi_errno;
fn_fail:
goto fn_exit;
}
int MPIR_Group_range_excl_impl(MPID_Group *group_ptr, int n, int ranges[][3], MPID_Group **new_group_ptr)
{
int mpi_errno = MPI_SUCCESS;
int size, i, j, k, nnew, first, last, stride;
MPID_MPI_STATE_DECL(MPID_STATE_MPIR_GROUP_RANGE_EXCL_IMPL);
MPID_MPI_FUNC_ENTER(MPID_STATE_MPIR_GROUP_RANGE_EXCL_IMPL);
/* Compute size, assuming that included ranks are valid (and distinct) */
size = group_ptr->size;
nnew = 0;
for (i = 0; i < n; i++) {
first = ranges[i][0]; last = ranges[i][1]; stride = ranges[i][2];
/* works for stride of either sign. Error checking above
has already guaranteed stride != 0 */
nnew += 1 + (last - first) / stride;
}
nnew = size - nnew;
if (nnew == 0) {
*new_group_ptr = MPID_Group_empty;
goto fn_exit;
}
/* Allocate a new group and lrank_to_lpid array */
mpi_errno = MPIR_Group_create( nnew, new_group_ptr );
/* --BEGIN ERROR HANDLING-- */
if (mpi_errno)
{
goto fn_fail;
}
/* --END ERROR HANDLING-- */
(*new_group_ptr)->rank = MPI_UNDEFINED;
/* Group members are taken in rank order from the original group,
with the specified members removed. Use the flag array for that
purpose. If this was a critical routine, we could use the
flag values set in the error checking part, if the error checking
was enabled *and* we are not MPI_THREAD_MULTIPLE, but since this
is a low-usage routine, we haven't taken that optimization. */
/* First, mark the members to exclude */
for (i = 0; i < size; i++)
group_ptr->lrank_to_lpid[i].flag = 0;
for (i = 0; i < n; i++) {
first = ranges[i][0]; last = ranges[i][1]; stride = ranges[i][2];
if (stride > 0) {
for (j = first; j <= last; j += stride) {
group_ptr->lrank_to_lpid[j].flag = 1;
}
}
else {
for (j = first; j >= last; j += stride) {
group_ptr->lrank_to_lpid[j].flag = 1;
}
}
}
/* Now, run through the group and pick up the members that were
not excluded */
k = 0;
for (i = 0; i < size; i++) {
if (!group_ptr->lrank_to_lpid[i].flag) {
(*new_group_ptr)->lrank_to_lpid[k].lrank = k;
(*new_group_ptr)->lrank_to_lpid[k].lpid = group_ptr->lrank_to_lpid[i].lpid;
if (group_ptr->rank == i) {
(*new_group_ptr)->rank = k;
}
k++;
}
}
/* TODO calculate is_local_dense_monotonic */
fn_exit:
MPID_MPI_FUNC_EXIT(MPID_STATE_MPIR_GROUP_RANGE_EXCL_IMPL);
return mpi_errno;
fn_fail:
goto fn_exit;
}
/*@
MPI_Group_excl - Produces a group by reordering an existing group and taking
only unlisted members
Input Parameters:
+ group - group (handle)
. n - number of elements in array 'ranks' (integer)
- ranks - array of integer ranks in 'group' not to appear in 'newgroup'
Output Parameter:
. newgroup - new group derived from above, preserving the order defined by
'group' (handle)
Note:
The MPI standard requires that each of the ranks to excluded must be
a valid rank in the group and all elements must be distinct or the
function is erroneous.
.N ThreadSafe
.N Fortran
.N Errors
.N MPI_SUCCESS
.N MPI_ERR_GROUP
.N MPI_ERR_EXHAUSTED
.N MPI_ERR_ARG
.N MPI_ERR_RANK
.seealso: MPI_Group_free
@*/
int MPI_Group_excl(MPI_Group group, int n, int *ranks, MPI_Group *newgroup)
{
static const char FCNAME[] = "MPI_Group_excl";
int mpi_errno = MPI_SUCCESS;
MPID_Group *group_ptr = NULL, *new_group_ptr;
int size, i, newi;
MPID_MPI_STATE_DECL(MPID_STATE_MPI_GROUP_EXCL);
MPIR_ERRTEST_INITIALIZED_ORDIE();
MPIU_THREAD_CS_ENTER(ALLFUNC,);
MPID_MPI_FUNC_ENTER(MPID_STATE_MPI_GROUP_EXCL);
/* Validate parameters, especially handles needing to be converted */
# ifdef HAVE_ERROR_CHECKING
{
MPID_BEGIN_ERROR_CHECKS;
{
MPIR_ERRTEST_GROUP(group, mpi_errno);
MPIR_ERRTEST_ARGNEG(n,"n",mpi_errno);
if (mpi_errno != MPI_SUCCESS) goto fn_fail;
}
MPID_END_ERROR_CHECKS;
}
# endif
/* Convert MPI object handles to object pointers */
MPID_Group_get_ptr( group, group_ptr );
# ifdef HAVE_ERROR_CHECKING
{
MPID_BEGIN_ERROR_CHECKS;
{
/* Validate group_ptr */
MPID_Group_valid_ptr( group_ptr, mpi_errno );
/* If group_ptr is not valid, it will be reset to null */
if (group_ptr) {
mpi_errno = MPIR_Group_check_valid_ranks( group_ptr,
ranks, n );
}
if (mpi_errno) goto fn_fail;
}
MPID_END_ERROR_CHECKS;
}
# endif /* HAVE_ERROR_CHECKING */
/* ... body of routine ... */
/* Allocate a new group and lrank_to_lpid array */
size = group_ptr->size;
if (size == n) {
*newgroup = MPI_GROUP_EMPTY;
goto fn_exit;
}
mpi_errno = MPIR_Group_create( size - n, &new_group_ptr );
/* --BEGIN ERROR HANDLING-- */
if (mpi_errno)
{
goto fn_fail;
}
/* --END ERROR HANDLING-- */
new_group_ptr->rank = MPI_UNDEFINED;
/* Use flag fields to mark the members to *exclude* . */
for (i=0; i<size; i++) {
group_ptr->lrank_to_lpid[i].flag = 0;
}
for (i=0; i<n; i++) {
group_ptr->lrank_to_lpid[ranks[i]].flag = 1;
}
newi = 0;
for (i=0; i<size; i++) {
if (group_ptr->lrank_to_lpid[i].flag == 0) {
new_group_ptr->lrank_to_lpid[newi].lrank = newi;
new_group_ptr->lrank_to_lpid[newi].lpid =
group_ptr->lrank_to_lpid[i].lpid;
if (group_ptr->rank == i) new_group_ptr->rank = newi;
newi++;
}
}
new_group_ptr->size = size - n;
new_group_ptr->idx_of_first_lpid = -1;
/* TODO calculate is_local_dense_monotonic */
MPIU_OBJ_PUBLISH_HANDLE(*newgroup, new_group_ptr->handle);
/* ... end of body of routine ... */
fn_exit:
MPID_MPI_FUNC_EXIT(MPID_STATE_MPI_GROUP_EXCL);
MPIU_THREAD_CS_EXIT(ALLFUNC,);
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_group_excl",
"**mpi_group_excl %G %d %p %p", group, n, ranks, newgroup);
}
# endif
mpi_errno = MPIR_Err_return_comm( NULL, FCNAME, mpi_errno );
goto fn_exit;
/* --END ERROR HANDLING-- */
}
/*@
MPI_Group_difference - Makes a group from the difference of two groups
Input Parameters:
+ group1 - first group (handle)
- group2 - second group (handle)
Output Parameter:
. newgroup - difference group (handle)
Notes:
The generated group containc the members of 'group1' that are not in 'group2'.
.N ThreadSafe
.N Fortran
.N Errors
.N MPI_SUCCESS
.N MPI_ERR_GROUP
.N MPI_ERR_EXHAUSTED
.seealso: MPI_Group_free
@*/
int MPI_Group_difference(MPI_Group group1, MPI_Group group2, MPI_Group *newgroup)
{
static const char FCNAME[] = "MPI_Group_difference";
int mpi_errno = MPI_SUCCESS;
MPID_Group *group_ptr1 = NULL;
MPID_Group *group_ptr2 = NULL;
MPID_Group *new_group_ptr;
int size1, i, k, g1_idx, g2_idx, l1_pid, l2_pid, nnew;
MPID_MPI_STATE_DECL(MPID_STATE_MPI_GROUP_DIFFERENCE);
MPIR_ERRTEST_INITIALIZED_ORDIE();
MPIU_THREAD_CS_ENTER(ALLFUNC,);
MPID_MPI_FUNC_ENTER(MPID_STATE_MPI_GROUP_DIFFERENCE);
/* Validate parameters, especially handles needing to be converted */
# ifdef HAVE_ERROR_CHECKING
{
MPID_BEGIN_ERROR_CHECKS;
{
MPIR_ERRTEST_GROUP(group1, mpi_errno);
MPIR_ERRTEST_GROUP(group2, mpi_errno);
if (mpi_errno != MPI_SUCCESS) goto fn_fail;
}
MPID_END_ERROR_CHECKS;
}
# endif
/* Convert MPI object handles to object pointers */
MPID_Group_get_ptr( group1, group_ptr1 );
MPID_Group_get_ptr( group2, group_ptr2 );
/* Validate parameters and objects (post conversion) */
# ifdef HAVE_ERROR_CHECKING
{
MPID_BEGIN_ERROR_CHECKS;
{
/* Validate group_ptr */
MPID_Group_valid_ptr( group_ptr1, mpi_errno );
MPID_Group_valid_ptr( group_ptr2, mpi_errno );
/* If either group_ptr is not valid, it will be reset to null */
if (mpi_errno) goto fn_fail;
}
MPID_END_ERROR_CHECKS;
}
# endif /* HAVE_ERROR_CHECKING */
/* ... body of routine ... */
/* Return a group consisting of the members of group1 that are *not*
in group2 */
size1 = group_ptr1->size;
/* Insure that the lpid lists are setup */
MPIR_Group_setup_lpid_pairs( group_ptr1, group_ptr2 );
for (i=0; i<size1; i++) {
group_ptr1->lrank_to_lpid[i].flag = 0;
}
g1_idx = group_ptr1->idx_of_first_lpid;
g2_idx = group_ptr2->idx_of_first_lpid;
nnew = size1;
while (g1_idx >= 0 && g2_idx >= 0) {
l1_pid = group_ptr1->lrank_to_lpid[g1_idx].lpid;
l2_pid = group_ptr2->lrank_to_lpid[g2_idx].lpid;
if (l1_pid < l2_pid) {
g1_idx = group_ptr1->lrank_to_lpid[g1_idx].next_lpid;
}
else if (l1_pid > l2_pid) {
g2_idx = group_ptr2->lrank_to_lpid[g2_idx].next_lpid;
}
else {
/* Equal */
group_ptr1->lrank_to_lpid[g1_idx].flag = 1;
g1_idx = group_ptr1->lrank_to_lpid[g1_idx].next_lpid;
g2_idx = group_ptr2->lrank_to_lpid[g2_idx].next_lpid;
nnew --;
}
}
/* Create the group */
if (nnew == 0) {
/* See 5.3.2, Group Constructors. For many group routines,
the standard explicitly says to return MPI_GROUP_EMPTY;
for others it is implied */
*newgroup = MPI_GROUP_EMPTY;
goto fn_exit;
}
else {
mpi_errno = MPIR_Group_create( nnew, &new_group_ptr );
/* --BEGIN ERROR HANDLING-- */
if (mpi_errno) {
goto fn_fail;
}
/* --END ERROR HANDLING-- */
new_group_ptr->rank = MPI_UNDEFINED;
k = 0;
for (i=0; i<size1; i++) {
if (!group_ptr1->lrank_to_lpid[i].flag) {
new_group_ptr->lrank_to_lpid[k].lrank = k;
new_group_ptr->lrank_to_lpid[k].lpid =
group_ptr1->lrank_to_lpid[i].lpid;
if (i == group_ptr1->rank)
new_group_ptr->rank = k;
k++;
}
}
/* TODO calculate is_local_dense_monotonic */
}
MPIU_OBJ_PUBLISH_HANDLE(*newgroup, new_group_ptr->handle);
/* ... end of body of routine ... */
fn_exit:
MPID_MPI_FUNC_EXIT(MPID_STATE_MPI_GROUP_DIFFERENCE);
MPIU_THREAD_CS_EXIT(ALLFUNC,);
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_group_difference",
"**mpi_group_difference %G %G %p", group1, group2, newgroup);
}
# endif
mpi_errno = MPIR_Err_return_comm( NULL, FCNAME, mpi_errno );
goto fn_exit;
/* --END ERROR HANDLING-- */
}