fix recurrent_op,test=develop (#17433)

paddle/fluid/framework/ir/memory_optimize_pass/record_skip_memory_opt_vars_pass.cc

@@ -140,9 +140,9 @@ class RecordSkipMemoryOptVarsPass : public ir::Pass {
         // fail since "states" and "ex_states" cannot be found in main block.
         // When memory optimization is enabled, "states", "ex_states" and their
         // gradient should be skipped.
-        auto& ex_states =
+        auto ex_states =
             boost::get<std::vector<std::string>>(op_desc->GetAttr("ex_states"));
-        auto& states =
+        auto states =
             boost::get<std::vector<std::string>>(op_desc->GetAttr("states"));
         if (op_type == "recurrent") {
           UpdateSkipVarSet(skip_vars, {ex_states, states});
@@ -154,7 +154,7 @@ class RecordSkipMemoryOptVarsPass : public ir::Pass {
           UpdateSkipVarSet(
               skip_vars,
               {ToGradVarName(op_desc->Input("parameters")),
-               ToGradVarName(op_desc->Input("input")), ex_states, states,
+               ToGradVarName(op_desc->Input("inputs")), ex_states, states,
                ToGradVarName(ex_states), ToGradVarName(states)});
         }
       }

paddle/fluid/operators/recurrent_op.cc

@@ -508,6 +508,7 @@ class RecurrentGradOp : public RecurrentBase {
     for (auto *sub_scope : *step_scopes) {
       const_cast<framework::Scope &>(scope).DeleteScope(sub_scope);
     }
+    step_scopes->clear();
   }
 
  private:

python/paddle/fluid/backward.py

@@ -232,15 +232,8 @@ def _remove_no_grad_branch_(op_descs, no_grad_set):
         for arg in op_desc.input_arg_names():
             if core.grad_var_suffix() in arg and arg in no_grad_set:
                 x_in = _strip_grad_suffix_(arg)
-                x_in_var_desc = op_desc.block().find_var_recursive(
-                    cpt.to_bytes(x_in))
-                assert x_in_var_desc is not None, "Variable {} not found".format(
-                    x_in)
-                dtype = x_in_var_desc.dtype()
-
-                to_insert.append(
-                    (_create_op_desc_("fill_zeros_like2", {"X": [x_in]},
-                                      {"Out": [arg]}, {"dtype": dtype}), idx))
+                to_insert.append((_create_op_desc_(
+                    "fill_zeros_like", {"X": [x_in]}, {"Out": [arg]}, {}), idx))
 
     list([op_descs.insert(p[1], p[0]) for p in reversed(to_insert)])