Fix Coverity CIDs 1341584-1341589.

ompi/mca/coll/base/coll_base_allgather.c

@@ -170,7 +170,7 @@ int ompi_coll_base_allgather_intra_bruck(const void *sbuf, int scount,
         char *free_buf = NULL, *shift_buf = NULL;
         ptrdiff_t span, gap;
 
-        span = opal_datatype_span(&rdtype->super, (size - rank) * rcount, &gap);
+        span = opal_datatype_span(&rdtype->super, (int64_t)(size - rank) * rcount, &gap);
 
         free_buf = (char*)calloc(span, sizeof(char));
         if (NULL == free_buf) {

ompi/mca/coll/base/coll_base_alltoall.c

@@ -219,7 +219,7 @@ int ompi_coll_base_alltoall_intra_bruck(const void *sbuf, int scount,
     err = ompi_datatype_type_extent (rdtype, &rext);
     if (err != MPI_SUCCESS) { line = __LINE__; goto err_hndl; }
 
-    span = opal_datatype_span(&sdtype->super, size * scount, &gap);
+    span = opal_datatype_span(&sdtype->super, (int64_t)size * scount, &gap);
 
     displs = (int *) malloc(size * sizeof(int));
     if (displs == NULL) { line = __LINE__; err = -1; goto err_hndl; }

ompi/mca/coll/base/coll_base_gather.c

@@ -66,8 +66,8 @@ ompi_coll_base_gather_intra_binomial(const void *sbuf, int scount,
 
     ompi_datatype_type_extent(sdtype, &sextent);
     ompi_datatype_type_extent(rdtype, &rextent);
-    ssize = opal_datatype_span(&sdtype->super, scount * size, &sgap);
-    rsize = opal_datatype_span(&rdtype->super, rcount * size, &rgap);
+    ssize = opal_datatype_span(&sdtype->super, (int64_t)scount * size, &sgap);
+    rsize = opal_datatype_span(&rdtype->super, (int64_t)rcount * size, &rgap);
 
     vrank = (rank - root + size) % size;
 

ompi/mca/coll/base/coll_base_scatter.c

@@ -65,8 +65,8 @@ ompi_coll_base_scatter_intra_binomial( const void *sbuf, int scount,
     ompi_datatype_type_extent(sdtype, &sextent);
     ompi_datatype_type_extent(rdtype, &rextent);
 
-    ssize = opal_datatype_span(&sdtype->super, scount * size, &sgap);
-    rsize = opal_datatype_span(&rdtype->super, rcount * size, &rgap);
+    ssize = opal_datatype_span(&sdtype->super, (int64_t)scount * size, &sgap);
+    rsize = opal_datatype_span(&rdtype->super, (int64_t)rcount * size, &rgap);
 
     vrank = (rank - root + size) % size;
     ptmp = (char *) rbuf;  /* by default suppose leaf nodes, just use rbuf */