def _generate_simple_tensorflow(comp):
tf_parser_callable = tree_to_cc_transformations.TFParser()
comp, _ = tree_transformations.insert_called_tf_identity_at_leaves(
comp)
comp, _ = transformation_utils.transform_postorder(
comp, tf_parser_callable)
return comp
def _generate_simple_tensorflow(comp):
"""Naively generates TensorFlow to represent `comp`."""
tf_parser_callable = tree_to_cc_transformations.TFParser()
comp, _ = tree_transformations.insert_called_tf_identity_at_leaves(comp)
comp, _ = transformation_utils.transform_postorder(comp,
tf_parser_callable)
return comp
def parse_tff_to_tf(comp):
comp, _ = tree_transformations.insert_called_tf_identity_at_leaves(comp)
parser_callable = tree_to_cc_transformations.TFParser()
comp, _ = tree_transformations.replace_called_lambda_with_block(comp)
comp, _ = tree_transformations.inline_block_locals(comp)
comp, _ = tree_transformations.replace_selection_from_tuple_with_element(comp)
new_comp, transformed = transformation_utils.transform_postorder(
comp, parser_callable)
return new_comp, transformed
def transform(self, local_function):
if not self.should_transform(local_function):
return local_function, False
refs_removed, _ = remove_called_lambdas_and_blocks(local_function)
parsed_to_tf, _ = remove_duplicate_called_graphs(refs_removed)
if parsed_to_tf.is_compiled_computation() or (
parsed_to_tf.is_call() and
parsed_to_tf.function.is_compiled_computation()):
return parsed_to_tf, True
# TODO(b/146430051): We should only end up in this case if
# `remove_called_lambdas_and_blocks` above is in its failure mode, IE,
# failing to resolve references due to too-deep indirection; we should
# remove this extra case and simply raise if we fail here when we fix the
# attached bug.
called_graphs_inserted, _ = tree_transformations.insert_called_tf_identity_at_leaves(
parsed_to_tf)
compiled_comp, _ = transformation_utils.transform_postorder(
called_graphs_inserted, self._naive_tf_parser)
return compiled_comp, True
def remove_duplicate_called_graphs(comp):
"""Deduplicates called graphs for a subset of TFF AST constructs.
Args:
comp: Instance of `building_blocks.ComputationBuildingBlock` whose called
graphs we wish to deduplicate, according to `tree_analysis.trees_equal`.
For `comp` to be eligible here, it must be either a lambda itself whose
body contains no lambdas or blocks, or another computation containing no
lambdas or blocks. This restriction is necessary because
`remove_duplicate_called_graphs` makes no effort to ensure that it is not
pulling references out of their defining scope, except for the case where
`comp` is a lambda itself. This function exits early and logs a warning if
this assumption is violated. Additionally, `comp` must contain only
computations which can be represented in TensorFlow, IE, satisfy the type
restriction in `type_analysis.is_tensorflow_compatible_type`.
Returns:
Either a called instance of `building_blocks.CompiledComputation` or a
`building_blocks.CompiledComputation` itself, depending on whether `comp`
is of non-functional or functional type respectively. Additionally, returns
a boolean to match the `transformation_utils.TransformSpec` pattern.
"""
py_typecheck.check_type(comp, building_blocks.ComputationBuildingBlock)
tree_analysis.check_has_unique_names(comp)
name_generator = building_block_factory.unique_name_generator(comp)
if comp.is_lambda():
comp_to_check = comp.result
else:
comp_to_check = comp
if tree_analysis.contains_types(comp_to_check, (
building_blocks.Block,
building_blocks.Lambda,
)):
logging.warning(
'The preprocessors have failed to remove called lambdas '
'and blocks; falling back to less efficient, but '
'guaranteed, TensorFlow generation with computation %s.', comp)
return comp, False
leaf_called_graphs = []
def _pack_called_graphs_into_block(inner_comp):
"""Packs deduplicated bindings to called graphs in `leaf_called_graphs`."""
if inner_comp.is_call() and inner_comp.function.is_compiled_computation():
for (name, x) in leaf_called_graphs:
if tree_analysis.trees_equal(x, inner_comp):
return building_blocks.Reference(name,
inner_comp.type_signature), True
new_name = next(name_generator)
leaf_called_graphs.append((new_name, inner_comp))
return building_blocks.Reference(new_name,
inner_comp.type_signature), True
return inner_comp, False
if comp.is_lambda():
transformed_result, _ = transformation_utils.transform_postorder(
comp.result, _pack_called_graphs_into_block)
packed_into_block = building_blocks.Block(leaf_called_graphs,
transformed_result)
parsed, _ = create_tensorflow_representing_block(packed_into_block)
tff_func = building_blocks.Lambda(comp.parameter_name, comp.parameter_type,
parsed)
tf_parser_callable = tree_to_cc_transformations.TFParser()
comp, _ = tree_transformations.insert_called_tf_identity_at_leaves(tff_func)
tf_generated, _ = transformation_utils.transform_postorder(
comp, tf_parser_callable)
else:
transformed_result, _ = transformation_utils.transform_postorder(
comp, _pack_called_graphs_into_block)
packed_into_block = building_blocks.Block(leaf_called_graphs,
transformed_result)
tf_generated, _ = create_tensorflow_representing_block(packed_into_block)
return tf_generated, True
