init reorder boot

paddle/operators/dynamic_recurrent_op.cc

@@ -28,6 +28,17 @@ inline void CreateVariables(Scope& scope,
   }
 }
 
+/*
+ * The inputs with sequence should be reordered when they are split, so the
+ * boot_states should be reordered in the same order.
+ *
+ * NOTE This may require that the `pre_state` of the first time step should just
+ * copy the `boot_state` rather than reference it, for that the content should
+ * be reordered, but the RNN op should not change the `boot_state` as an input
+ * variable's content.
+ */
+inline void ReorderBootState();
+
 }  // namespace detail
 
 class DynamicRecurrentOpProtoAndCheckerMaker
@@ -79,8 +90,7 @@ void DynamicRecurrentOp::SplitInputs() const {
   // TODO(superjom) make level a config
   // TODO(superjom) check all the inputs has the same LoD
   int level = 0;
-  const auto& inlinks = cache_.inlinks;
-  for (auto& item : inlinks) {
+  for (auto& item : cache_.inlinks) {
     const auto& var = item.second;
     const auto& tensor = var->Get<LoDTensor>();
     TensorArray& ta = step_inputs_[item.first];
@@ -115,6 +125,11 @@ void DynamicRecurrentOp::WriteStepInputs() const {
 }
 
 void DynamicRecurrentOp::WriteStepOutputs() const {
+  // initialize step outputs
+  PADDLE_ENFORCE_GT(cache_.outlinks.size(), 0UL);
+  for (const auto& item : cache_.outlinks) {
+    step_outputs_.emplace(item.first, TensorArray());
+  }
   for (size_t step = 0; step < cache_.scopes->size(); step++) {
     auto& scope = cache_.GetScope(step);
     for (auto& item : step_outputs_) {