add check for allreduce fusion

mindspore/ccsrc/frontend/parallel/step_parallel.cc

@@ -1895,7 +1895,11 @@ LossNodeInfo FindLossCNode(const FuncGraphPtr &func_graph) {
   MS_EXCEPTION_IF_NULL(pre_node);
 
   auto pre_cnode = pre_node->cast<CNodePtr>();
-  if (pre_cnode == nullptr) {
+  if (pre_cnode == nullptr || !IsValueNode<Primitive>(pre_cnode->input(0))) {
+    return loss_node_info;
+  }
+  if (!IsValueNode<Primitive>(pre_cnode->input(0))) {
+    MS_LOG(DEBUG) << "pre_cnode:" << pre_cnode->ToString();
     return loss_node_info;
   }
   auto prim = GetValueNode<PrimitivePtr>(pre_cnode->input(0));

mindspore/parallel/_auto_parallel_context.py

@@ -294,6 +294,12 @@ class _AutoParallelContext:
         else:
             raise TypeError('indices must be a python list')
 
+        if len(set(indices)) != len(indices):
+            raise ValueError('indices has duplicate elements')
+
+        if sorted(indices) != indices:
+            raise ValueError('elements in indices must be sorted in ascending order')
+
         if isinstance(group, (str)):
             group_len = len(group)
             if group_len > _MAX_GROUP_NAME_LEN:
@@ -308,7 +314,7 @@ class _AutoParallelContext:
                 group = _DEFAULT_NCCL_FUSION_GROUP_NAME
 
         self._context_handle.set_all_reduce_fusion_split_indices(indices, group)
-        if context.get_context("device_target") == "Ascend":
+        if context.get_context("device_target") == "Ascend" and context.get_context("enable_ge"):
             _set_fusion_strategy_by_idx(indices)
 
     def get_all_reduce_fusion_split_indices(self, group=""):