Reverse Sequence small fixes

Signed-off-by: maheshambule <mahesh_ambule@persistent.com>

include/tvm/relay/attrs/transform.h

@@ -187,9 +187,9 @@ struct ReverseSequenceAttrs : public tvm::AttrsNode<ReverseSequenceAttrs> {
   Integer batch_axis;
 
   TVM_DECLARE_ATTRS(ReverseSequenceAttrs, "relay.attrs.ReverseSequenceAttrs") {
-    TVM_ATTR_FIELD(seq_axis).set_default(NullValue<Integer>())
+    TVM_ATTR_FIELD(seq_axis).set_default(1)
         .describe("The seq axis along which to reverse elements.");
-    TVM_ATTR_FIELD(batch_axis).set_default(NullValue<Integer>())
+    TVM_ATTR_FIELD(batch_axis).set_default(0)
         .describe("The batch axis along which to slice the tensor.");
   }
 };  // struct ReverseSequenceAttrs

python/tvm/relay/frontend/tflite.py

@@ -1738,9 +1738,7 @@ def convert_reverse_sequence(self, op):
         batch_axis = options.BatchDim()
         seq_axis = options.SeqDim()
 
-        out = _op.reverse_sequence(in_expr, length_expr, seq_axis, batch_axis)
-
-        return out
+        return _op.reverse_sequence(in_expr, length_expr, seq_axis, batch_axis)
 
     def convert_cast(self, op):
         """Convert TFLite CAST"""
@@ -2384,7 +2382,7 @@ def has_expr(self, input_tensor_idx):
         return self.exp_tab.has_expr(get_tensor_name(self.subgraph, input_tensor_idx))
 
     def get_tensor_expr(self, tensor):
-        """ Return the expr for tensor. """
+        """ Return the Relay expr for tensor. """
         if self.has_expr(tensor.tensor_idx):
             expr = self.get_expr(tensor.tensor_idx)
         else:

src/relay/op/tensor/transform.cc

@@ -1438,6 +1438,7 @@ Array<te::Tensor> ReverseCompute(const Attrs& attrs,
                                  const Type& out_type) {
   const ReverseAttrs *param = attrs.as<ReverseAttrs>();
   CHECK(param != nullptr);
+  //pass empty seq_length tensor to reverse_sequence
   return { topi::reverse_sequence(inputs[0], te::Tensor(), param->axis)};
 }
 

topi/python/topi/transform.py

@@ -138,7 +138,7 @@ def reverse_sequence(a, seq_lengths, seq_axis=1, batch_axis=0):
 
     Parameters
     ----------
-    data : tvm.te.Tensor
+    a : tvm.te.Tensor
        The tensor to be reversed.
 
     seq_lengths : tvm.te.Tensor

topi/src/transform.cc

@@ -44,6 +44,7 @@ TVM_REGISTER_GLOBAL("topi.transpose")
 
 TVM_REGISTER_GLOBAL("topi.flip")
 .set_body([](TVMArgs args, TVMRetValue *rv) {
+  //pass empty seq_lengths tensor to reverse_sequence
   *rv = reverse_sequence(args[0], Tensor(), args[1]);
   });