Remove shortcut optimizations from non-blocking collectives. We need to call

into the collectives module even in the shortcutable cases to get the requests
created.

This commit was SVN r26784.

ompi/mpi/c/iallgather.c

@@ -88,28 +88,6 @@ int MPI_Iallgather(void *sendbuf, int sendcount, MPI_Datatype sendtype,
         OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);
     }
 
-    /* Do we need to do anything?  Everyone had to give the same send
-       signature, which means that everyone must have given a
-       sendcount > 0 if there's anything to send for the intra-communicator
-       case.  If we're doing IN_PLACE, however, check recvcount, 
-       not sendcount. */
-    if ( OMPI_COMM_IS_INTRA(comm) ) {
-       if ((MPI_IN_PLACE != sendbuf && 0 == sendcount) ||
-            (0 == recvcount)) {
-            return MPI_SUCCESS;
-       }
-    }
-    else if ( OMPI_COMM_IS_INTER(comm) ){
-        /* for inter comunicators, the communication pattern
-           need not be symmetric. Specifically, one group is
-	   allows to have sendcount=0, while the other has
-           a valid sendcount. Thus, the only way not to do
-           anything is if both sendcount and recvcount are zero. */
-        if ( 0 == sendcount && 0 == recvcount ) {
-            return MPI_SUCCESS;
-        }
-    }
-
     OPAL_CR_ENTER_LIBRARY();
 
     /* Invoke the coll component to perform the back-end operation */

ompi/mpi/c/iallgatherv.c

@@ -111,27 +111,6 @@ int MPI_Iallgatherv(void *sendbuf, int sendcount, MPI_Datatype sendtype,
         }
     }
 
-    /* Do we need to do anything?  Everyone had to give the same 
-       signature, which means that everyone must have given a
-       sum(recvounts) > 0 if there's anything to do. */
-
-    if ( OMPI_COMM_IS_INTRA( comm) ) {
-	for (i = 0; i < ompi_comm_size(comm); ++i) {
-	    if (0 != recvcounts[i]) {
-		break;
-	    }
-	}
-	if (i >= ompi_comm_size(comm)) {
-	    return MPI_SUCCESS;
-	}
-    }
-    /* There is no rule that can be applied for inter-communicators, since
-       recvcount(s)=0 only indicates that the processes in the other group 
-       do not send anything, sendcount=0 only indicates that I do not send
-       anything. However, other processes in my group might very well send 
-       something */
-
-
     OPAL_CR_ENTER_LIBRARY();
 
     /* Invoke the coll component to perform the back-end operation */

ompi/mpi/c/iallreduce.c

@@ -89,14 +89,6 @@ int MPI_Iallreduce(void *sendbuf, void *recvbuf, int count,
         OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);
     }
 
-    /* MPI-1, p114, says that each process must supply at least
-       one element.  But at least the Pallas benchmarks call
-       MPI_REDUCE with a count of 0.  So be sure to handle it. */
-    
-    if (0 == count) {
-        return MPI_SUCCESS;
-    }
-
     OPAL_CR_ENTER_LIBRARY();
 
     /* Invoke the coll component to perform the back-end operation */

ompi/mpi/c/ialltoall.c

@@ -75,12 +75,6 @@ int MPI_Ialltoall(void *sendbuf, int sendcount, MPI_Datatype sendtype,
       OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);
     }
 
-    /* Do we need to do anything? */
-
-    if (0 == sendcount && 0 == recvcount) {
-        return MPI_SUCCESS;
-    }
-
     OPAL_CR_ENTER_LIBRARY();
 
     /* Invoke the coll component to perform the back-end operation */

ompi/mpi/c/ibarrier.c

@@ -56,21 +56,7 @@ int MPI_Ibarrier(MPI_Comm comm, MPI_Request *request)
 
     OPAL_CR_ENTER_LIBRARY();
 
-    /* Intracommunicators: Only invoke the back-end coll module barrier
+    err = comm->c_coll.coll_ibarrier(comm, request, comm->c_coll.coll_ibarrier_module);
-       function if there's more than one process in the communicator */
-
-    if (OMPI_COMM_IS_INTRA(comm)) {
-        if (ompi_comm_size(comm) > 1) {
-            err = comm->c_coll.coll_ibarrier(comm, request, comm->c_coll.coll_ibarrier_module);
-        }
-    } 
-
-    /* Intercommunicators -- always invoke, because, by definition,
-       there's always at least 2 processes in an intercommunicator. */
-
-    else {
-        err = comm->c_coll.coll_ibarrier(comm, request, comm->c_coll.coll_ibarrier_module);
-    }
 
     /* All done */
 

ompi/mpi/c/iexscan.c

@@ -71,14 +71,6 @@ int MPI_Iexscan(void *sendbuf, void *recvbuf, int count,
         OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);
     }
 
-    /* Do we need to do anything? (MPI says that reductions have to
-       have a count of at least 1, but at least IMB calls reduce with
-       a count of 0 -- blah!) */
-
-    if (0 == count) {
-        return MPI_SUCCESS;
-    }
-
     OPAL_CR_ENTER_LIBRARY();
 
     /* Invoke the coll component to perform the back-end operation */

ompi/mpi/c/igather.c

@@ -160,17 +160,6 @@ int MPI_Igather(void *sendbuf, int sendcount, MPI_Datatype sendtype,
         }
     }
 
-    /* Do we need to do anything? */
-
-    if ((0 == sendcount && MPI_ROOT != root && 
-         (ompi_comm_rank(comm) != root ||
-          (ompi_comm_rank(comm) == root && MPI_IN_PLACE != sendbuf))) ||
-        (ompi_comm_rank(comm) == root && MPI_IN_PLACE == sendbuf && 
-         0 == recvcount) || 
-        (0 == recvcount && (MPI_ROOT == root || MPI_PROC_NULL == root))) {
-        return MPI_SUCCESS;
-    }
-
     OPAL_CR_ENTER_LIBRARY();
 
     /* Invoke the coll component to perform the back-end operation */

ompi/mpi/c/ireduce.c

@@ -116,14 +116,6 @@ int MPI_Ireduce(void *sendbuf, void *recvbuf, int count,
         }
     }
 
-    /* Do we need to do anything? (MPI says that reductions have to
-       have a count of at least 1, but at least IMB calls reduce with
-       a count of 0 -- blah!) */
-
-    if (0 == count) {
-        return MPI_SUCCESS;
-    }
-
     OPAL_CR_ENTER_LIBRARY();
 
     /* Invoke the coll component to perform the back-end operation */

ompi/mpi/c/ireduce_scatter.c

@@ -105,20 +105,6 @@ int MPI_Ireduce_scatter(void *sendbuf, void *recvbuf, int *recvcounts,
         }
     }
 
-    /* MPI-1, p114, says that each process must supply at least one
-       element.  But at least the Pallas benchmarks call MPI_REDUCE
-       with a count of 0.  So be sure to handle it.  Grrr... */
-
-    size = ompi_comm_size(comm);
-    for (count = i = 0; i < size; ++i) {
-        if (0 == recvcounts[i]) {
-            ++count;
-        }
-    }
-    if (size == count) {
-        return MPI_SUCCESS;
-    }
-
     OPAL_CR_ENTER_LIBRARY();
 
     /* Invoke the coll component to perform the back-end operation */

ompi/mpi/c/iscan.c

@@ -85,14 +85,6 @@ int MPI_Iscan(void *sendbuf, void *recvbuf, int count,
         OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);
     }
 
-    /* Do we need to do anything? (MPI says that reductions have to
-       have a count of at least 1, but at least IMB calls reduce with
-       a count of 0 -- blah!) */
-
-    if (0 == count) {
-        return MPI_SUCCESS;
-    }
-
     OPAL_CR_ENTER_LIBRARY();
 
     /* Call the coll component to actually perform the allgather */

ompi/mpi/c/iscatter.c

@@ -143,17 +143,6 @@ int MPI_Iscatter(void *sendbuf, int sendcount, MPI_Datatype sendtype,
         }
     }
 
-    /* Do we need to do anything? */
-
-    if ((0 == recvcount && MPI_ROOT != root && 
-         (ompi_comm_rank(comm) != root || 
-          (ompi_comm_rank(comm) == root && MPI_IN_PLACE != recvbuf))) ||
-        (ompi_comm_rank(comm) == root && MPI_IN_PLACE == recvbuf &&
-         0 == sendcount) || 
-	(0 == sendcount && (MPI_ROOT == root || MPI_PROC_NULL == root))) {
-        return MPI_SUCCESS;
-    }
-
     OPAL_CR_ENTER_LIBRARY();
 
     /* Invoke the coll component to perform the back-end operation */