/
xla.py
55 lines (47 loc) · 2.02 KB
/
xla.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
# Copyright 2018 The TensorFlow Probability Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ============================================================================
"""XLA utilities."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import tensorflow.compat.v2 as tf
__all__ = ['compile_nested_output']
def compile_nested_output(f, compile_fn=None):
"""Wraps f with a `tpu.rewrite` or `xla.compile`, propagates output structure.
`xla.compile` insists `f` output a flat list of `Tensor`s or `Op`s, but
tolerates nested input arguments. Here, we capture the output structure in
order to propagate it.
Args:
f: Callable to compile, may accept/return nested inputs/outputs.
compile_fn: The function to use to compile, i.e. `xla.compile` or
`tpu.rewrite`. Accepts two args, `f` and `inputs`.
Returns:
g: Callable wrapping `f` which returns XLA-compiled, nested outputs.
"""
def _wrapper(*inputs): # pylint:disable=missing-docstring
nest = tf.nest
struct = [None]
def _flattened(*inputs):
result = f(*inputs)
flat = nest.flatten(result)
# Ick: Side-effect. Ideally we could push output nest support into
# tpu.rewrite / xla.compile. b/121383831
struct[0] = nest.pack_sequence_as(result, [1] * len(flat))
return flat
res = compile_fn(_flattened, inputs)
if struct[0] is None:
raise ValueError('Expected nest structure in struct[0]')
return nest.pack_sequence_as(struct[0], res)
return _wrapper