# Copyright 2022 Cerebras Systems.
#
# 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.
import re
from typing import Tuple
import torch
from modelzoo.common.pytorch.model_utils.checkpoint_converters.base_converter import (
BaseCheckpointConverter_HF_CS,
BaseConfigConverter,
ConversionRule,
EquivalentSubkey,
FormatVersions,
)
from modelzoo.common.pytorch.model_utils.checkpoint_converters.bert import (
ConfigConverter_Bert_HF_CS18,
Converter_BertLayerNorm_HF_CS,
Converter_BertModel_CS16_CS17,
Converter_BertPretrainModel_HF_CS18,
)
[docs]class Converter_RobertaPretrainModel_HF_CS(BaseCheckpointConverter_HF_CS):
[docs] def __init__(self):
super().__init__()
self.rules = [
ConversionRule(
[
EquivalentSubkey("roberta.", "bert_encoder."),
Converter_BertModel_CS16_CS17(), # CS16 = HF
],
),
# CLS:
ConversionRule(
[
EquivalentSubkey(
"lm_head.dense",
"bert_mlm_head.mlm_transform.ffn.ffn.0.linear_layer",
),
"\.(?:weight|bias)",
],
action=self.replaceKey,
),
ConversionRule(
[
EquivalentSubkey(
"lm_head.", "bert_mlm_head.mlm_transform.",
),
Converter_BertLayerNorm_HF_CS("layer_norm", "ln"),
],
action=None,
),
ConversionRule(
[
EquivalentSubkey(
"lm_head.decoder",
"bert_mlm_head.classifier.ffn.0.linear_layer",
),
"\.weight",
],
action=self.replaceKey,
),
ConversionRule(
[
EquivalentSubkey(
"lm_head.decoder",
"bert_mlm_head.classifier.ffn.0.linear_layer",
),
"\.bias",
],
action=self.convert_cls_predictions_bias,
),
ConversionRule(["lm_head\.bias"], exists="left"),
]
@staticmethod
def formats() -> Tuple[FormatVersions, FormatVersions]:
return (FormatVersions("hf"), FormatVersions("cs"))
@staticmethod
def get_config_converter_class() -> BaseConfigConverter:
return None
def convert_cls_predictions_bias(
self,
old_key,
new_key,
old_state_dict,
new_state_dict,
from_index,
action_fn_args,
):
self.replaceKey(
old_key,
new_key,
old_state_dict,
new_state_dict,
from_index,
action_fn_args,
)
if from_index == 1:
# HF stores an extra copy of the decoder bias in the predictions object itself
bias_key = re.sub("\.decoder\.", ".", new_key)
self.replaceKey(
old_key,
bias_key,
old_state_dict,
new_state_dict,
from_index,
action_fn_args,
)
[docs]class Converter_RobertaPretrainModel_HF_CS18(
Converter_BertPretrainModel_HF_CS18
):
[docs] def __init__(self):
super().__init__()
self.rules = [
# Catch checkpoints from Pytorch 2.0 API
ConversionRule(
[Converter_RobertaPretrainModel_HF_CS(),], action=None,
),
# Catch checkpoints from 1.7/1.8
ConversionRule(
[
EquivalentSubkey("", "model."),
Converter_RobertaPretrainModel_HF_CS(),
],
action=None,
),
]
@classmethod
def converter_note(cls) -> str:
return "{} <-> {} for RobertaForPreTraining".format(
cls.formats()[0], cls.formats()[1]
)
@staticmethod
def get_config_converter_class() -> BaseConfigConverter:
return ConfigConverter_Roberta_HF_CS18
[docs] def post_model_convert(
self,
old_state_dict,
new_state_dict,
configs,
from_index,
drop_unmatched_keys,
):
if from_index == 1:
num_segments = configs[1]["model"]["num_segments"]
if not num_segments:
new_state_dict[
"roberta.embeddings.token_type_embeddings.weight"
] = torch.zeros(
configs[0]["type_vocab_size"], configs[0]["hidden_size"]
)
super().post_model_convert(
old_state_dict,
new_state_dict,
configs,
from_index,
drop_unmatched_keys,
)
[docs]class ConfigConverter_Roberta_HF_CS18(ConfigConverter_Bert_HF_CS18):
[docs] def __init__(self):
super().__init__()
# Override Bert's config converter with the following:
self.rules = [
ConversionRule(
["model_type"],
action=BaseConfigConverter.assert_factory_fn(0, "roberta"),
),
ConversionRule(
["max_position_embeddings"], action=self.convert_max_pos_embed,
),
ConversionRule(
[EquivalentSubkey("type_vocab_size", "num_segments")],
action=self.convert_num_segments,
),
ConversionRule(["pad_token_id"], action=self.replaceKey,),
ConversionRule(
["mask_padding_in_positional_embed"],
action=BaseConfigConverter.assert_factory_fn(1, True),
),
ConversionRule(
["disable_nsp"],
action=BaseConfigConverter.assert_factory_fn(1, True),
),
ConversionRule(
["mlm_nonlinearity"],
action=BaseConfigConverter.assert_factory_fn(1, "gelu"),
),
*self.rules,
]
self.pre_convert_defaults[0].update(
{
"vocab_size": 50265,
"position_embedding_type": "absolute",
"type_vocab_size": 2,
"pad_token_id": 1,
}
)
self.pre_convert_defaults[1].update(
{
"disable_nsp": False,
"pad_token_id": 0,
"mask_padding_in_positional_embed": False,
}
)
self.post_convert_defaults[0].update({"model_type": "roberta"})
self.post_convert_defaults[1].update(
{"disable_nsp": True, "mask_padding_in_positional_embed": True,}
)
def convert_num_segments(
self,
old_key,
new_key,
old_state_dict,
new_state_dict,
from_index,
action_fn_args,
):
# CS allows segment embeddings to be disabled while HF doesn't
# When it is disabled in CS, we need to enable it in HF and set the
# embedding weight to zero
if from_index == 1 and old_state_dict[old_key] == 0:
new_state_dict[new_key] = 1
else:
new_state_dict[new_key] = old_state_dict[old_key]
def convert_max_pos_embed(
self,
old_key,
new_key,
old_state_dict,
new_state_dict,
from_index,
action_fn_args,
):
# The number of positional embeddings = MSL + pad token offset + 1
# HF refers to number of positional embeddings (the total) as
# max_position_embeddings while we refer to MSL as
# max_position_embeddings
if from_index == 0:
new_state_dict[new_key] = (
old_state_dict[old_key] - old_state_dict["pad_token_id"] - 1
)
else:
new_state_dict[new_key] = (
old_state_dict[old_key] + old_state_dict["pad_token_id"] + 1
)
def pre_config_convert(
self, config, from_index,
):
config = super().pre_config_convert(config, from_index)
if from_index == 1:
if "num_segments" not in config:
config["num_segments"] = 0 if config["disable_nsp"] else 2
return config
def post_config_convert(
self,
original_config,
old_config,
new_config,
from_index,
drop_unmatched_keys,
):
if from_index == 0:
new_config["mlm_nonlinearity"] = "gelu"
return super().post_config_convert(
original_config,
old_config,
new_config,
from_index,
drop_unmatched_keys,
)