!7022 [AutoParallel]Fix find loss and root reshape bug

Merge pull request !7022 from lichen/fix_auto_parallel_find_loss_bug

mindspore/ccsrc/frontend/parallel/step_parallel.cc

@@ -1852,14 +1852,14 @@ LossNodeInfo FindLossCNode(const FuncGraphPtr &func_graph) {
   if (pre_cnode == nullptr) {
     return loss_node_info;
   }
-  pre_cnode = HandleDependLoss(pre_cnode);
-  auto current_prim = GetValueNode<PrimitivePtr>(pre_cnode->input(0));
+  auto prim = GetValueNode<PrimitivePtr>(pre_cnode->input(0));
   // return -> cast
-  if (current_prim->name() == CAST && !pre_cnode->has_user_data<OperatorInfo>()) {
+  if (prim->name() == CAST && !pre_cnode->has_user_data<OperatorInfo>()) {
     pre_cnode = pre_cnode->input(1)->cast<CNodePtr>();
     MS_EXCEPTION_IF_NULL(pre_cnode);
-    current_prim = GetValueNode<PrimitivePtr>(pre_cnode->input(0));
   }
+  pre_cnode = HandleDependLoss(pre_cnode);
+  auto current_prim = GetValueNode<PrimitivePtr>(pre_cnode->input(0));
 
   // notice: the GetNext op has not input
   if (INVALID_LOSS_OPS.find(current_prim->name()) != INVALID_LOSS_OPS.end()) {
@@ -2416,6 +2416,12 @@ void InsertShapeOp(const CNodePtr &node, const AnfNodePtr &pre_node, const FuncG
   // shape op doesn't have params and attrs.
   OperatorParams params;
   OperatorAttrs attrs;
+  auto shape_value = GetValueNode(node->input(2))->cast<ValueSequeuePtr>();
+  MS_EXCEPTION_IF_NULL(shape_value);
+  auto shape = shape_value->value();
+  if (shape.empty()) {
+    return;
+  }
   OperatorArgs args = std::make_pair(attrs, params);
   Operator op = std::make_pair(SHAPE_OP, args);
   InsertNode(op, node, 2, pre_node, root, "shape");