无法使用 TF 2.4.1 将 onnx 模型转换为 tflite
Can't convert onnx model to tflite using TF 2.4.1
我有一个 ONNX 模型，我可以使用 TF 2.4.1 将其成功转换为 TF。但是在将保存的模型转换为 TFLite 时发生错误。
代码：
import onnx
import tensorflow as tf
from onnx_tf.backend import prepare
print(tf.__version__)
# Convert model.onnx to Tensorflow
onnx_model = onnx.load('model.onnx')
onnx.checker.check_model(onnx_model)
tf_rep = prepare(onnx_model)
tf_rep.export_graph('model')
# Convert saved model to tflite
converter = tf.lite.TFLiteConverter.from_saved_model('model')
tf_lite_model = converter.convert()
open('model.tflite', 'wb').write(tf_lite_model)
一切顺利，直到转换步骤结束，如下所示：
>>> tf_lite_model = converter.convert()
2021-04-22 18:18:14.715046: W tensorflow/compiler/mlir/lite/python/tf_tfl_flatbuffer_helpers.cc:316] Ignored output_format.
2021-04-22 18:18:14.715072: W tensorflow/compiler/mlir/lite/python/tf_tfl_flatbuffer_helpers.cc:319] Ignored drop_control_dependency.
2021-04-22 18:18:14.715078: W tensorflow/compiler/mlir/lite/python/tf_tfl_flatbuffer_helpers.cc:325] Ignored change_concat_input_ranges.
2021-04-22 18:18:14.716044: I tensorflow/cc/saved_model/reader.cc:32] Reading SavedModel from: model
2021-04-22 18:18:14.778050: I tensorflow/cc/saved_model/reader.cc:55] Reading meta graph with tags { serve }
2021-04-22 18:18:14.778083: I tensorflow/cc/saved_model/reader.cc:93] Reading SavedModel debug info (if present) from: model
2021-04-22 18:18:14.998062: I tensorflow/compiler/mlir/mlir_graph_optimization_pass.cc:196] None of the MLIR optimization passes are enabled (registered 0 passes)
2021-04-22 18:18:15.043862: I tensorflow/cc/saved_model/loader.cc:206] Restoring SavedModel bundle.
2021-04-22 18:18:15.438804: I tensorflow/cc/saved_model/loader.cc:190] Running initialization op on SavedModel bundle at path: model
2021-04-22 18:18:15.809851: I tensorflow/cc/saved_model/loader.cc:277] SavedModel load for tags { serve }; Status: success: OK. Took 1093808 microseconds.
2021-04-22 18:18:18.757257: I tensorflow/compiler/mlir/tensorflow/utils/dump_mlir_util.cc:194] disabling MLIR crash reproducer, set env var `MLIR_CRASH_REPRODUCER_DIRECTORY` to enable.
loc(callsite(callsite("Pad_16@__inference___call___16503" at "PartitionedCall@__inference_signature_wrapper_16752") at "PartitionedCall")): error: operand #0 does not dominate this use
Traceback (most recent call last):
File "/Users/decades/anaconda3/envs/py38/lib/python3.8/site-packages/tensorflow/lite/python/convert.py", line 210, in toco_convert_protos
model_str = wrap_toco.wrapped_toco_convert(model_flags_str,
File "/Users/decades/anaconda3/envs/py38/lib/python3.8/site-packages/tensorflow/lite/python/wrap_toco.py", line 32, in wrapped_toco_convert
return _pywrap_toco_api.TocoConvert(
Exception: <unknown>:0: error: loc(callsite(callsite("Pad_16@__inference___call___16503" at "PartitionedCall@__inference_signature_wrapper_16752") at "PartitionedCall")): operand #0 does not dominate this use
<unknown>:0: note: loc("PartitionedCall"): called from
<unknown>:0: note: loc(callsite(callsite("Pad_16@__inference___call___16503" at "PartitionedCall@__inference_signature_wrapper_16752") at "PartitionedCall")): operand defined here
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/Users/decades/anaconda3/envs/py38/lib/python3.8/site-packages/tensorflow/lite/python/lite.py", line 739, in convert
result = _convert_saved_model(**converter_kwargs)
File "/Users/decades/anaconda3/envs/py38/lib/python3.8/site-packages/tensorflow/lite/python/convert.py", line 632, in convert_saved_model
data = toco_convert_protos(
File "/Users/decades/anaconda3/envs/py38/lib/python3.8/site-packages/tensorflow/lite/python/convert.py", line 216, in toco_convert_protos
raise ConverterError(str(e))
tensorflow.lite.python.convert.ConverterError: <unknown>:0: error: loc(callsite(callsite("Pad_16@__inference___call___16503" at "PartitionedCall@__inference_signature_wrapper_16752") at "PartitionedCall")): operand #0 does not dominate this use
<unknown>:0: note: loc("PartitionedCall"): called from
<unknown>:0: note: loc(callsite(callsite("Pad_16@__inference___call___16503" at "PartitionedCall@__inference_signature_wrapper_16752") at "PartitionedCall")): operand defined here
我不知道这条消息是什么意思，但如果我切换到 TF 2.2，转换会出现 w/o 错误。糟糕的是，由于另一个问题，现在初始 ONNX 到 TF 的转换失败了。
有人知道这条消息的含义以及可以用它做什么吗？
TIA
可以把你保存的模型目录分享给我吗？我可以帮忙调试
一般的建议是，有两种可能性
(1) TF Lite 转换器可能无法正确处理保存的模型。
(2) onnx 转换工具可能无法创建有效的 TF 保存模型。
使用最新的 TF 版本（2.5 或 tf-nightly）可能有助于解决第 (1) 种情况下的此问题，但不能保证。
我确认 tf-nightly 版本可以毫无问题地转换附加的保存模型：
converter = tf.lite.TFLiteConverter.from_saved_model(
"/tmp/onnx_model")
tflite_model = converter.convert()
with open("/tmp/onnx.tflite", "wb") as f:
f.write(tflite_model)
我有一个 ONNX 模型，我可以使用 TF 2.4.1 将其成功转换为 TF。但是在将保存的模型转换为 TFLite 时发生错误。
代码：
import onnx
import tensorflow as tf
from onnx_tf.backend import prepare
print(tf.__version__)
# Convert model.onnx to Tensorflow
onnx_model = onnx.load('model.onnx')
onnx.checker.check_model(onnx_model)
tf_rep = prepare(onnx_model)
tf_rep.export_graph('model')
# Convert saved model to tflite
converter = tf.lite.TFLiteConverter.from_saved_model('model')
tf_lite_model = converter.convert()
open('model.tflite', 'wb').write(tf_lite_model)
一切顺利，直到转换步骤结束，如下所示：
>>> tf_lite_model = converter.convert()
2021-04-22 18:18:14.715046: W tensorflow/compiler/mlir/lite/python/tf_tfl_flatbuffer_helpers.cc:316] Ignored output_format.
2021-04-22 18:18:14.715072: W tensorflow/compiler/mlir/lite/python/tf_tfl_flatbuffer_helpers.cc:319] Ignored drop_control_dependency.
2021-04-22 18:18:14.715078: W tensorflow/compiler/mlir/lite/python/tf_tfl_flatbuffer_helpers.cc:325] Ignored change_concat_input_ranges.
2021-04-22 18:18:14.716044: I tensorflow/cc/saved_model/reader.cc:32] Reading SavedModel from: model
2021-04-22 18:18:14.778050: I tensorflow/cc/saved_model/reader.cc:55] Reading meta graph with tags { serve }
2021-04-22 18:18:14.778083: I tensorflow/cc/saved_model/reader.cc:93] Reading SavedModel debug info (if present) from: model
2021-04-22 18:18:14.998062: I tensorflow/compiler/mlir/mlir_graph_optimization_pass.cc:196] None of the MLIR optimization passes are enabled (registered 0 passes)
2021-04-22 18:18:15.043862: I tensorflow/cc/saved_model/loader.cc:206] Restoring SavedModel bundle.
2021-04-22 18:18:15.438804: I tensorflow/cc/saved_model/loader.cc:190] Running initialization op on SavedModel bundle at path: model
2021-04-22 18:18:15.809851: I tensorflow/cc/saved_model/loader.cc:277] SavedModel load for tags { serve }; Status: success: OK. Took 1093808 microseconds.
2021-04-22 18:18:18.757257: I tensorflow/compiler/mlir/tensorflow/utils/dump_mlir_util.cc:194] disabling MLIR crash reproducer, set env var `MLIR_CRASH_REPRODUCER_DIRECTORY` to enable.
loc(callsite(callsite("Pad_16@__inference___call___16503" at "PartitionedCall@__inference_signature_wrapper_16752") at "PartitionedCall")): error: operand #0 does not dominate this use
Traceback (most recent call last):
File "/Users/decades/anaconda3/envs/py38/lib/python3.8/site-packages/tensorflow/lite/python/convert.py", line 210, in toco_convert_protos
model_str = wrap_toco.wrapped_toco_convert(model_flags_str,
File "/Users/decades/anaconda3/envs/py38/lib/python3.8/site-packages/tensorflow/lite/python/wrap_toco.py", line 32, in wrapped_toco_convert
return _pywrap_toco_api.TocoConvert(
Exception: <unknown>:0: error: loc(callsite(callsite("Pad_16@__inference___call___16503" at "PartitionedCall@__inference_signature_wrapper_16752") at "PartitionedCall")): operand #0 does not dominate this use
<unknown>:0: note: loc("PartitionedCall"): called from
<unknown>:0: note: loc(callsite(callsite("Pad_16@__inference___call___16503" at "PartitionedCall@__inference_signature_wrapper_16752") at "PartitionedCall")): operand defined here
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/Users/decades/anaconda3/envs/py38/lib/python3.8/site-packages/tensorflow/lite/python/lite.py", line 739, in convert
result = _convert_saved_model(**converter_kwargs)
File "/Users/decades/anaconda3/envs/py38/lib/python3.8/site-packages/tensorflow/lite/python/convert.py", line 632, in convert_saved_model
data = toco_convert_protos(
File "/Users/decades/anaconda3/envs/py38/lib/python3.8/site-packages/tensorflow/lite/python/convert.py", line 216, in toco_convert_protos
raise ConverterError(str(e))
tensorflow.lite.python.convert.ConverterError: <unknown>:0: error: loc(callsite(callsite("Pad_16@__inference___call___16503" at "PartitionedCall@__inference_signature_wrapper_16752") at "PartitionedCall")): operand #0 does not dominate this use
<unknown>:0: note: loc("PartitionedCall"): called from
<unknown>:0: note: loc(callsite(callsite("Pad_16@__inference___call___16503" at "PartitionedCall@__inference_signature_wrapper_16752") at "PartitionedCall")): operand defined here
我不知道这条消息是什么意思，但如果我切换到 TF 2.2，转换会出现 w/o 错误。糟糕的是，由于另一个问题，现在初始 ONNX 到 TF 的转换失败了。
有人知道这条消息的含义以及可以用它做什么吗？
TIA
可以把你保存的模型目录分享给我吗？我可以帮忙调试
一般的建议是，有两种可能性
(1) TF Lite 转换器可能无法正确处理保存的模型。
(2) onnx 转换工具可能无法创建有效的 TF 保存模型。
使用最新的 TF 版本（2.5 或 tf-nightly）可能有助于解决第 (1) 种情况下的此问题，但不能保证。
我确认 tf-nightly 版本可以毫无问题地转换附加的保存模型：
converter = tf.lite.TFLiteConverter.from_saved_model(
"/tmp/onnx_model")
tflite_model = converter.convert()
with open("/tmp/onnx.tflite", "wb") as f:
f.write(tflite_model)