!11996 fix bug of split optimizer.

From: @liu_xiao_93
Reviewed-by: @liangchenghui,@wuxuejian
Signed-off-by: @liangchenghui

mindspore/ccsrc/backend/optimizer/ascend/enhancer/split_n_optimizer.cc

@@ -90,6 +90,7 @@ KernelWithIndex VisitSplitKernel(const AnfNodePtr &anf_node, size_t index) {
 bool InputCheck(const AnfNodePtr &node) {
   MS_EXCEPTION_IF_NULL(node);
   auto cnode = node->cast<CNodePtr>();
+  MS_EXCEPTION_IF_NULL(cnode);
   auto in_nums = AnfAlgo::GetInputTensorNum(node);
   for (size_t i = 0; i < in_nums; i++) {
     auto in_node = VisitSplitKernel(AnfAlgo::GetInputNode(cnode, i), 0).first;
@@ -98,7 +99,9 @@ bool InputCheck(const AnfNodePtr &node) {
       return false;
     }
     if (in_node->isa<CNode>()) {
-      auto in_node_name = AnfAlgo::GetCNodeName(in_node->cast<CNodePtr>());
+      auto in_cnode = in_node->cast<CNodePtr>();
+      MS_EXCEPTION_IF_NULL(in_cnode);
+      auto in_node_name = AnfAlgo::GetCNodeName(in_cnode);
       auto trans_input = AnfAlgo::VisitKernel(in_node, 0).first;
       if (in_node_name == kTransDataOpName && (trans_input->isa<Parameter>() || trans_input->isa<ValueNode>())) {
         MS_LOG(INFO) << "Data->TransData->split, can not optimizer.";
@@ -107,9 +110,9 @@ bool InputCheck(const AnfNodePtr &node) {
       if (in_node_name == prim::kPrimControlDepend->name() || in_node_name == prim::kPrimDepend->name()) {
         return false;
       }
-      if ((AnfAlgo::HasNodeAttr("non_task", cnode) && AnfAlgo::GetNodeAttr<bool>(cnode, "non_task")) ||
-          (AnfAlgo::HasNodeAttr("nop_node", cnode) && AnfAlgo::GetNodeAttr<bool>(cnode, "nop_node"))) {
-        MS_LOG(INFO) << "Input has non_task or nop_node attr, can not optimizer.";
+      if ((AnfAlgo::HasNodeAttr("non_task", in_cnode) && AnfAlgo::GetNodeAttr<bool>(in_node, "non_task")) ||
+          opt::IsNopNode(in_cnode)) {
+        MS_LOG(INFO) << "Input is nop node or has non_task attr, can not optimizer.";
         return false;
       }
     }
@@ -140,7 +143,7 @@ bool OutputCheck(const FuncGraphPtr &func_graph, const AnfNodePtr &node) {
       return false;
     }
     auto op_name = AnfAlgo ::GetCNodeName(item);
-    if (InvalidOps.find(op_name) != InvalidOps.end() || AnfAlgo::IsCommunicationOp(node)) {
+    if (InvalidOps.find(op_name) != InvalidOps.end() || AnfAlgo::IsCommunicationOp(item)) {
       MS_LOG(INFO) << "Next node is " << item->fullname_with_scope() << ", not a invalid node, can not optimizer.";
       return false;
     }