coll/base CID 1516784+1516786: fix bad shift

This almost certainly never happens in practice, but we might as well
be defensive and handle the error case.

Signed-off-by: Jeff Squyres <jsquyres@cisco.com>

Author: jsquyres

ompi/mca/coll/base/coll_base_allreduce.c

@@ -17,6 +17,7 @@
  *                         and Technology (RIST). All rights reserved.
  * Copyright (c) 2018      Siberian State University of Telecommunications
  *                         and Information Science. All rights reserved.
+ * Copyright (c) 2022      Cisco Systems, Inc.  All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -982,7 +983,9 @@ int ompi_coll_base_allreduce_intra_redscat_allgather(
 
     /* Find nearest power-of-two less than or equal to comm_size */
     int nsteps = opal_hibit(comm_size, comm->c_cube_dim + 1);   /* ilog2(comm_size) */
-    assert(nsteps >= 0);
+    if (-1 == nsteps) {
+        return MPI_ERR_ARG;
+    }
     int nprocs_pof2 = 1 << nsteps;                              /* flp2(comm_size) */
 
     if (count < nprocs_pof2 || !ompi_op_is_commute(op)) {

ompi/mca/coll/base/coll_base_reduce.c

@@ -17,6 +17,7 @@
  * Copyright (c) 2016-2017 IBM Corporation.  All rights reserved.
  * Copyright (c) 2018      Siberian State University of Telecommunications
  *                         and Information Science. All rights reserved.
+ * Copyright (c) 2022      Cisco Systems, Inc.  All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -812,7 +813,9 @@ int ompi_coll_base_reduce_intra_redscat_gather(
 
     /* Find nearest power-of-two less than or equal to comm_size */
     int nsteps = opal_hibit(comm_size, comm->c_cube_dim + 1);   /* ilog2(comm_size) */
-    assert(nsteps >= 0);
+    if (-1 == nsteps) {
+        return MPI_ERR_ARG;
+    }
     int nprocs_pof2 = 1 << nsteps;                              /* flp2(comm_size) */
 
     if (nprocs_pof2 < 2 || count < nprocs_pof2 || !ompi_op_is_commute(op)) {