!13104 insert parallel optimizer once

From: @gong_zi_yan
Reviewed-by: @stsuteng,@kisnwang
Signed-off-by: @stsuteng

mindspore/ccsrc/frontend/parallel/step_parallel.cc

@@ -1571,7 +1571,7 @@ std::pair<AnfNodePtr, int64_t> FindSubGraph(const FuncGraphPtr &graph, const Anf
 }
 
 static void InsertAllGatherOp(const FuncGraphPtr &root, const std::string &group, const std::pair<AnfNodePtr, int> &res,
-                              const AnfNodePtr &node) {
+                              const AnfNodePtr &node, const std::string &op_name) {
   MS_EXCEPTION_IF_NULL(res.first);
   MS_EXCEPTION_IF_NULL(node);
   auto cnode = res.first->cast<CNodePtr>();
@@ -1579,10 +1579,9 @@ static void InsertAllGatherOp(const FuncGraphPtr &root, const std::string &group
   MS_EXCEPTION_IF_NULL(graph);
   auto cnode_prim = GetValueNode<PrimitivePtr>(cnode->input(0));
   MS_EXCEPTION_IF_NULL(cnode_prim);
-  int64_t grad_accumulation_step = ParallelContext::GetInstance()->grad_accumulation_step();
   Operator op;
   CNodePtr allgather;
-  if (grad_accumulation_step > 1) {
+  if (op_name == MINI_STEP_ALL_GATHER) {
     op = CreateMiniStepAllGatherOp(group);
     auto param_name = node->cast<ParameterPtr>()->name();
     if (cnode_prim->name() == CAST) {
@@ -1613,21 +1612,41 @@ static void ApplyParallelOptOnParam(const FuncGraphPtr &root, const AnfNodePtr &
   }
   FuncGraphManagerPtr manager = root->manager();
   MS_EXCEPTION_IF_NULL(manager);
+  int64_t grad_accumulation_step = ParallelContext::GetInstance()->grad_accumulation_step();
+  std::string op_name;
+  if (grad_accumulation_step > 1) {
+    op_name = MINI_STEP_ALL_GATHER;
+  } else {
+    op_name = ALL_GATHER;
+  }
   auto param_sub_set = manager->node_users()[parameter];
+  bool insert_flag = false;
   for (auto &param_pair : param_sub_set) {
     auto cnode = param_pair.first->cast<CNodePtr>();
     MS_EXCEPTION_IF_NULL(cnode);
     if (cnode->in_forward_flag()) {
       OperatorInfoPtr distribute_operator = cnode->user_data<OperatorInfo>();
       if (distribute_operator == nullptr) {
-        MS_LOG(WARNING) << "Parallel optimizer: " << cnode->ToString() << " 's OperatorInfoPtr is nullptr";
+        MS_LOG(WARNING) << "Parallel optimizer: " << GetPrimName(cnode) << " 's OperatorInfoPtr is nullptr";
       } else if (IntToSize(param_pair.second - 1) >= distribute_operator->inputs_tensor_info().size()) {
         MS_LOG(EXCEPTION) << "The index is out of range, index is  " << param_pair.second - 1 << ", vector size is  "
                           << distribute_operator->inputs_tensor_info().size();
       }
-      // insert allgather operator between shard parameter and cnode
-      InsertAllGatherOp(root, opt_shard_group, param_pair, parameter);
-      MS_LOG(INFO) << "Parallel optimizer is applied between " << parameter->ToString() << " and " << cnode->ToString();
+      if (insert_flag) {
+        auto next_cnode = FindCNode(parameter, op_name, cnode->func_graph());
+        if (next_cnode.first) {
+          manager->SetEdge(cnode, SizeToLong(param_pair.second), next_cnode.second);
+          MS_LOG(INFO) << "Parallel optimizer is applied between " << parameter->ToString() << " and "
+                       << GetPrimName(cnode);
+          continue;
+        }
+      } else {
+        // insert allgather operator between shard parameter and cnode
+        InsertAllGatherOp(root, opt_shard_group, param_pair, parameter, op_name);
+        MS_LOG(INFO) << "Parallel optimizer is applied between " << parameter->ToString() << " and "
+                     << GetPrimName(cnode);
+        insert_flag = true;
+      }
     }
   }
 }