fix cast and mix_cast bug

mindspore/ccsrc/pipeline/pynative/pynative_execute.cc

@@ -323,12 +323,6 @@ OpExecInfoPtr GenerateOpExecInfo(const py::args &args) {
   }
   op_exec_info->py_primitive = prim;
   op_exec_info->op_attrs = py::getattr(args[PY_PRIM], "attrs");
-  auto inst = PynativeExecutor::GetInstance();
-  if (inst->grad_flag()) {
-    op_exec_info->value = inst->GetForwardValue(op_exec_info);
-  } else {
-    (void)GetOpId(op_exec_info);
-  }
   op_exec_info->op_inputs = args[PY_INPUTS];
   ConvertInputs(prim, args[PY_INPUTS], op_exec_info);
   return op_exec_info;
@@ -903,6 +897,12 @@ py::tuple PynativeExecutor::RunOpInner(const py::args &args) {
     MS_LOG(DEBUG) << "set prim " << op_exec_info->op_name << mindspore::ToString(args_spec_list);
   }
 
+  if (PynativeExecutor::GetInstance()->grad_flag()) {
+    op_exec_info->value = PynativeExecutor::GetInstance()->GetForwardValue(op_exec_info);
+  } else {
+    (void)GetOpId(op_exec_info);
+  }
+
   auto result = RunOpInner(op_exec_info);
   py::object out_real = result;
   if (result.size() == 1) {