Change Equal 11 for string input (#2149)

* Change Equal 11 for string input * Unify the dtype of all of inputs and add backend test --------- Signed-off-by: Mike Essenmacher <essen@us.ibm.com>

Author: Mike Essenmacher

tests/test_backend.py

@@ -1421,6 +1421,14 @@ def func(x1, x2):
  return tf.identity(mi, name=_TFOUTPUT)
  self._run_test_case(func, [_OUTPUT], {_INPUT: x_val1, _INPUT1: x_val2})
 
+ def test_equal_string(self):
+ x_val1 = np.array(['1'], dtype=np.string_)
+ x_val2 = np.array(['2'], dtype=np.string_)
+ def func(x1, x2):
+ mi = tf.equal(x1, x2)
+ return tf.identity(mi, name=_TFOUTPUT)
+ self._run_test_case(func, [_OUTPUT], {_INPUT: x_val1, _INPUT1: x_val2})
+
  def test_equal(self):
  x_val1 = np.array([4, 2, 4, 1], dtype=np.int32).reshape((2, 2))
  x_val2 = np.array([2, 4, 4, 1], dtype=np.int32).reshape((2, 2))

tf2onnx/onnx_opset/logical.py

@@ -29,15 +29,21 @@ def _add_cast_to_inputs(graph, node, supported_dtypes, target_dtype):
  graph.copy_shape(inp, inp_cast.output[0])
  graph.set_dtype(inp_cast.output[0], target_dtype)
 
-
-def _add_cast_to_same_type_to_inputs(graph, node):
+def _add_cast_to_same_type_to_inputs(graph, node, supported_dtypes, target_dtype):
  common_dtype = graph.get_dtype(node.input[0])
+ if common_dtype not in supported_dtypes:
+ common_dtype = target_dtype
 
- for inp in node.input[1:]:
+ for inp in node.input:
  if graph.get_dtype(inp) != common_dtype:
  inp_cast = graph.insert_new_node_on_input(node, "Cast", inp, to=common_dtype)
  graph.copy_shape(inp, inp_cast.output[0])
  graph.set_dtype(inp_cast.output[0], common_dtype)
+ if graph.is_const(inp) and graph.get_tensor_value(inp) == '':
+ # Convert '' string constant to -1 int
+ # https://github.com/tensorflow/tensorflow/blob/4e7f0185c70faf35e12acbfe381a729d1e6cc38c/tensorflow/python/feature_column/feature_column.py#L2286
+ const_node = graph.get_node_by_output(inp)
+ const_node.set_tensor_value(utils.np.array(-1))
 
 
 @tf_op("LogicalNot", onnx_op="Not")
@@ -92,8 +98,24 @@ def version_7(cls, ctx, node, **kwargs):
 
  @classmethod
  def version_11(cls, ctx, node, **kwargs):
- # starting with opset-11, equal supports all types (but both operands must be of the same type)
- _add_cast_to_same_type_to_inputs(ctx, node)
+ # starting with opset-11, equal supports all numerical types (but both operands must be of the same type)
+ # string type is not supported
+ supported_dtypes = [
+ TensorProto.BOOL,
+ TensorProto.DOUBLE,
+ TensorProto.FLOAT,
+ TensorProto.FLOAT16,
+ TensorProto.INT8,
+ TensorProto.INT16,
+ TensorProto.INT32,
+ TensorProto.INT64,
+ TensorProto.UINT8,
+ TensorProto.UINT16,
+ TensorProto.UINT32,
+ TensorProto.UINT64
+ ]
+ target_dtype = TensorProto.INT32
+ _add_cast_to_same_type_to_inputs(ctx, node, supported_dtypes, target_dtype)
  need_not = node.type == "NotEqual"
  if need_not:
  node.type = "Equal"