bug fix for scalar input HCCL ops

mindspore/ccsrc/backend/optimizer/pass/communication_op_fusion.cc

@@ -204,7 +204,9 @@ AnfNodePtr CommunicationOpFusion::CreateFusedCommunicationOp(const FuncGraphPtr
       auto cnode = communication_op_info.communication_op_nodes[idx];
       MS_EXCEPTION_IF_NULL(cnode);
       std::vector<size_t> shape = AnfAlgo::GetOutputInferShape(cnode, 0);
-      shape[0] /= rank_size;
+      if (!shape.empty()) {
+        shape[0] /= rank_size;
+      }
       shapes.push_back(shape);
     }
   }