coll/libnbc: fix MPI_IN_PLACE handling in i{gather,scatter}[v]

MPI_IN_PLACE is only relevant on the root task, so only test is there

Signed-off-by: Gilles Gouaillardet <gilles@rist.or.jp>

ompi/mca/coll/libnbc/nbc_igather.c

@@ -8,7 +8,7 @@
  * Copyright (c) 2013      The University of Tennessee and The University
  *                         of Tennessee Research Foundation.  All rights
  *                         reserved.
- * Copyright (c) 2014-2015 Research Organization for Information Science
+ * Copyright (c) 2014-2016 Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  * Copyright (c) 2015      Los Alamos National Security, LLC. All rights
  *                         reserved.
@@ -46,13 +46,14 @@ int ompi_coll_libnbc_igather(const void* sendbuf, int sendcount, MPI_Datatype se
   int rank, p, res;
   MPI_Aint rcvext = 0;
   NBC_Schedule *schedule;
-  char *rbuf, inplace;
+  char *rbuf, inplace = 0;
   NBC_Handle *handle;
   ompi_coll_libnbc_module_t *libnbc_module = (ompi_coll_libnbc_module_t*) module;
 
-  NBC_IN_PLACE(sendbuf, recvbuf, inplace);
-
   rank = ompi_comm_rank (comm);
+  if (root == rank) {
+    NBC_IN_PLACE(sendbuf, recvbuf, inplace);
+  }
   p = ompi_comm_size (comm);
 
   if (rank == root) {

ompi/mca/coll/libnbc/nbc_igatherv.c

@@ -8,7 +8,7 @@
  * Copyright (c) 2013      The University of Tennessee and The University
  *                         of Tennessee Research Foundation.  All rights
  *                         reserved.
- * Copyright (c) 2014-2015 Research Organization for Information Science
+ * Copyright (c) 2014-2016 Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  * Copyright (c) 2015      Los Alamos National Security, LLC.  All rights
  *                         reserved.
@@ -31,13 +31,14 @@ int ompi_coll_libnbc_igatherv(const void* sendbuf, int sendcount, MPI_Datatype s
   int rank, p, res;
   MPI_Aint rcvext = 0;
   NBC_Schedule *schedule;
-  char *rbuf, inplace;
+  char *rbuf, inplace = 0;
   NBC_Handle *handle;
   ompi_coll_libnbc_module_t *libnbc_module = (ompi_coll_libnbc_module_t*) module;
 
-  NBC_IN_PLACE(sendbuf, recvbuf, inplace);
-
   rank = ompi_comm_rank (comm);
+  if (root == rank) {
+    NBC_IN_PLACE(sendbuf, recvbuf, inplace);
+  }
   p = ompi_comm_size (comm);
 
   if (rank == root) {

ompi/mca/coll/libnbc/nbc_iscatter.c

@@ -10,7 +10,7 @@
  * Copyright (c) 2013      The University of Tennessee and The University
  *                         of Tennessee Research Foundation.  All rights
  *                         reserved.
- * Copyright (c) 2014-2015 Research Organization for Information Science
+ * Copyright (c) 2014-2016 Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  *
  * Author(s): Torsten Hoefler <htor@cs.indiana.edu>
@@ -47,13 +47,15 @@ int ompi_coll_libnbc_iscatter (const void* sendbuf, int sendcount, MPI_Datatype
   int rank, p, res;
   MPI_Aint sndext = 0;
   NBC_Schedule *schedule;
-  char *sbuf, inplace;
+  char *sbuf, inplace = 0;
   NBC_Handle *handle;
   ompi_coll_libnbc_module_t *libnbc_module = (ompi_coll_libnbc_module_t*) module;
 
-  NBC_IN_PLACE(sendbuf, recvbuf, inplace);
 
   rank = ompi_comm_rank (comm);
+  if (root == rank) {
+    NBC_IN_PLACE(sendbuf, recvbuf, inplace);
+  }
   p = ompi_comm_size (comm);
 
   if (rank == root) {

ompi/mca/coll/libnbc/nbc_iscatterv.c

@@ -10,7 +10,7 @@
  * Copyright (c) 2013      The University of Tennessee and The University
  *                         of Tennessee Research Foundation.  All rights
  *                         reserved.
- * Copyright (c) 2014-2015 Research Organization for Information Science
+ * Copyright (c) 2014-2016 Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  *
  * Author(s): Torsten Hoefler <htor@cs.indiana.edu>
@@ -30,13 +30,15 @@ int ompi_coll_libnbc_iscatterv(const void* sendbuf, const int *sendcounts, const
   int rank, p, res;
   MPI_Aint sndext;
   NBC_Schedule *schedule;
-  char *sbuf, inplace;
+  char *sbuf, inplace = 0;
   NBC_Handle *handle;
   ompi_coll_libnbc_module_t *libnbc_module = (ompi_coll_libnbc_module_t*) module;
 
-  NBC_IN_PLACE(sendbuf, recvbuf, inplace);
-
   rank = ompi_comm_rank (comm);
+  if (root == rank) {
+    NBC_IN_PLACE(sendbuf, recvbuf, inplace);
+  }
+
   p = ompi_comm_size (comm);
 
   schedule = OBJ_NEW(NBC_Schedule);