[Eager]Fix tile API final_state and Backward bug (#41385)

* [Eager]Fix tile API final_state bug

* fix backward bug

paddle/fluid/eager/backward.cc

@@ -580,8 +580,9 @@ std::vector<paddle::experimental::Tensor> RunBackward(
       node_input_buffers_dict[grad_node] =
           std::make_unique<GradTensorHolder>(grad_node->InputMeta());
     }
-
-    if (grad_tensors.size() > 0) {
+    bool copy_from_grad_t =
+        grad_tensors.size() > 0 && grad_tensors[i].initialized();
+    if (copy_from_grad_t) {
       PADDLE_ENFORCE(
           grad_tensors.size() == tensors.size(),
           paddle::platform::errors::Fatal(
@@ -594,7 +595,6 @@ std::vector<paddle::experimental::Tensor> RunBackward(
       // Deep copy
       node_input_buffers_dict[grad_node]->CopyValueFromTensor(
           input_info.first, input_info.second, grad_tensors[i]);
-
     } else {
       VLOG(6) << "Fill grad input tensor " << i << " with 1.0";
       // Initialize tensor with 1.0

paddle/fluid/pybind/eager_utils.cc

@@ -213,6 +213,9 @@ std::vector<paddle::experimental::Tensor> CastPyArg2VectorOfTensor(
       if (PyObject_IsInstance(item,
                               reinterpret_cast<PyObject*>(p_tensor_type))) {
         result.emplace_back(reinterpret_cast<TensorObject*>(item)->tensor);
+      } else if (item == Py_None) {
+        // emplace empty Tensor for None
+        result.emplace_back();
       } else {
         PADDLE_THROW(platform::errors::InvalidArgument(
             "argument (position %d) must be "
@@ -229,6 +232,9 @@ std::vector<paddle::experimental::Tensor> CastPyArg2VectorOfTensor(
       if (PyObject_IsInstance(item,
                               reinterpret_cast<PyObject*>(p_tensor_type))) {
         result.emplace_back(reinterpret_cast<TensorObject*>(item)->tensor);
+      } else if (item == Py_None) {
+        // emplace empty Tensor for None
+        result.emplace_back();
       } else {
         PADDLE_THROW(platform::errors::InvalidArgument(
             "argument (position %d) must be "

python/paddle/tensor/manipulation.py

@@ -1751,6 +1751,11 @@ def tile(x, repeat_times, name=None):
             # [[1, 2, 3, 1, 2, 3]]
     """
     if in_dygraph_mode():
+        if isinstance(repeat_times, core.eager.Tensor):
+            assert (repeat_times.ndim == 1,
+                    "Only support ndim == 1 while repeat_times is a Tensor.")
+            repeat_times = repeat_times.numpy().tolist()
+
         return _C_ops.final_state_tile(x, repeat_times)
 
     if _in_legacy_dygraph():