in src/transformers/models/deprecated/bort/convert_bort_original_gluonnlp_checkpoint_to_pytorch.py [0:0]
def convert_bort_checkpoint_to_pytorch(bort_checkpoint_path: str, pytorch_dump_folder_path: str):
"""
Convert the original Bort checkpoint (based on MXNET and Gluonnlp) to our BERT structure-
"""
# Original Bort configuration
bort_4_8_768_1024_hparams = {
"attention_cell": "multi_head",
"num_layers": 4,
"units": 1024,
"hidden_size": 768,
"max_length": 512,
"num_heads": 8,
"scaled": True,
"dropout": 0.1,
"use_residual": True,
"embed_size": 1024,
"embed_dropout": 0.1,
"word_embed": None,
"layer_norm_eps": 1e-5,
"token_type_vocab_size": 2,
}
predefined_args = bort_4_8_768_1024_hparams
# Let's construct the original Bort model here
# Taken from official BERT implementation, see:
# https://github.com/alexa/bort/blob/master/bort/bort.py
encoder = BERTEncoder(
attention_cell=predefined_args["attention_cell"],
num_layers=predefined_args["num_layers"],
units=predefined_args["units"],
hidden_size=predefined_args["hidden_size"],
max_length=predefined_args["max_length"],
num_heads=predefined_args["num_heads"],
scaled=predefined_args["scaled"],
dropout=predefined_args["dropout"],
output_attention=False,
output_all_encodings=False,
use_residual=predefined_args["use_residual"],
activation=predefined_args.get("activation", "gelu"),
layer_norm_eps=predefined_args.get("layer_norm_eps", None),
)
# Vocab information needs to be fetched first
# It's the same as RoBERTa, so RobertaTokenizer can be used later
vocab_name = "openwebtext_ccnews_stories_books_cased"
# Specify download folder to Gluonnlp's vocab
gluon_cache_dir = os.path.join(get_home_dir(), "models")
bort_vocab = _load_vocab(vocab_name, None, gluon_cache_dir, cls=Vocab)
original_bort = nlp.model.BERTModel(
encoder,
len(bort_vocab),
units=predefined_args["units"],
embed_size=predefined_args["embed_size"],
embed_dropout=predefined_args["embed_dropout"],
word_embed=predefined_args["word_embed"],
use_pooler=False,
use_token_type_embed=False,
token_type_vocab_size=predefined_args["token_type_vocab_size"],
use_classifier=False,
use_decoder=False,
)
original_bort.load_parameters(bort_checkpoint_path, cast_dtype=True, ignore_extra=True)
params = original_bort._collect_params_with_prefix()
# Build our config 🤗
hf_bort_config_json = {
"architectures": ["BertForMaskedLM"],
"attention_probs_dropout_prob": predefined_args["dropout"],
"hidden_act": "gelu",
"hidden_dropout_prob": predefined_args["dropout"],
"hidden_size": predefined_args["embed_size"],
"initializer_range": 0.02,
"intermediate_size": predefined_args["hidden_size"],
"layer_norm_eps": predefined_args["layer_norm_eps"],
"max_position_embeddings": predefined_args["max_length"],
"model_type": "bort",
"num_attention_heads": predefined_args["num_heads"],
"num_hidden_layers": predefined_args["num_layers"],
"pad_token_id": 1, # 2 = BERT, 1 = RoBERTa
"type_vocab_size": 1, # 2 = BERT, 1 = RoBERTa
"vocab_size": len(bort_vocab),
}
hf_bort_config = BertConfig.from_dict(hf_bort_config_json)
hf_bort_model = BertForMaskedLM(hf_bort_config)
hf_bort_model.eval()
# Parameter mapping table (Gluonnlp to Transformers)
# * denotes layer index
#
# | Gluon Parameter | Transformers Parameter
# | -------------------------------------------------------------- | ----------------------
# | `encoder.layer_norm.beta` | `bert.embeddings.LayerNorm.bias`
# | `encoder.layer_norm.gamma` | `bert.embeddings.LayerNorm.weight`
# | `encoder.position_weight` | `bert.embeddings.position_embeddings.weight`
# | `word_embed.0.weight` | `bert.embeddings.word_embeddings.weight`
# | `encoder.transformer_cells.*.attention_cell.proj_key.bias` | `bert.encoder.layer.*.attention.self.key.bias`
# | `encoder.transformer_cells.*.attention_cell.proj_key.weight` | `bert.encoder.layer.*.attention.self.key.weight`
# | `encoder.transformer_cells.*.attention_cell.proj_query.bias` | `bert.encoder.layer.*.attention.self.query.bias`
# | `encoder.transformer_cells.*.attention_cell.proj_query.weight` | `bert.encoder.layer.*.attention.self.query.weight`
# | `encoder.transformer_cells.*.attention_cell.proj_value.bias` | `bert.encoder.layer.*.attention.self.value.bias`
# | `encoder.transformer_cells.*.attention_cell.proj_value.weight` | `bert.encoder.layer.*.attention.self.value.weight`
# | `encoder.transformer_cells.*.ffn.ffn_2.bias` | `bert.encoder.layer.*.attention.output.dense.bias`
# | `encoder.transformer_cells.*.ffn.ffn_2.weight` | `bert.encoder.layer.*.attention.output.dense.weight`
# | `encoder.transformer_cells.*.layer_norm.beta` | `bert.encoder.layer.*.attention.output.LayerNorm.bias`
# | `encoder.transformer_cells.*.layer_norm.gamma` | `bert.encoder.layer.*.attention.output.LayerNorm.weight`
# | `encoder.transformer_cells.*.ffn.ffn_1.bias` | `bert.encoder.layer.*.intermediate.dense.bias`
# | `encoder.transformer_cells.*.ffn.ffn_1.weight` | `bert.encoder.layer.*.intermediate.dense.weight`
# | `encoder.transformer_cells.*.ffn.layer_norm.beta` | `bert.encoder.layer.*.output.LayerNorm.bias`
# | `encoder.transformer_cells.*.ffn.layer_norm.gamma` | `bert.encoder.layer.*.output.LayerNorm.weight`
# | `encoder.transformer_cells.*.proj.bias` | `bert.encoder.layer.*.output.dense.bias`
# | `encoder.transformer_cells.*.proj.weight` | `bert.encoder.layer.*.output.dense.weight`
# Helper function to convert MXNET Arrays to PyTorch
def to_torch(mx_array) -> nn.Parameter:
return nn.Parameter(torch.FloatTensor(mx_array.data().asnumpy()))
# Check param shapes and map new HF param back
def check_and_map_params(hf_param, gluon_param):
shape_hf = hf_param.shape
gluon_param = to_torch(params[gluon_param])
shape_gluon = gluon_param.shape
assert shape_hf == shape_gluon, (
f"The gluon parameter {gluon_param} has shape {shape_gluon}, but expects shape {shape_hf} for Transformers"
)
return gluon_param
hf_bort_model.bert.embeddings.word_embeddings.weight = check_and_map_params(
hf_bort_model.bert.embeddings.word_embeddings.weight, "word_embed.0.weight"
)
hf_bort_model.bert.embeddings.position_embeddings.weight = check_and_map_params(
hf_bort_model.bert.embeddings.position_embeddings.weight, "encoder.position_weight"
)
hf_bort_model.bert.embeddings.LayerNorm.bias = check_and_map_params(
hf_bort_model.bert.embeddings.LayerNorm.bias, "encoder.layer_norm.beta"
)
hf_bort_model.bert.embeddings.LayerNorm.weight = check_and_map_params(
hf_bort_model.bert.embeddings.LayerNorm.weight, "encoder.layer_norm.gamma"
)
# Inspired by RoBERTa conversion script, we just zero them out (Bort does not use them)
hf_bort_model.bert.embeddings.token_type_embeddings.weight.data = torch.zeros_like(
hf_bort_model.bert.embeddings.token_type_embeddings.weight.data
)
for i in range(hf_bort_config.num_hidden_layers):
layer: BertLayer = hf_bort_model.bert.encoder.layer[i]
# self attention
self_attn: BertSelfAttention = layer.attention.self
self_attn.key.bias.data = check_and_map_params(
self_attn.key.bias.data, f"encoder.transformer_cells.{i}.attention_cell.proj_key.bias"
)
self_attn.key.weight.data = check_and_map_params(
self_attn.key.weight.data, f"encoder.transformer_cells.{i}.attention_cell.proj_key.weight"
)
self_attn.query.bias.data = check_and_map_params(
self_attn.query.bias.data, f"encoder.transformer_cells.{i}.attention_cell.proj_query.bias"
)
self_attn.query.weight.data = check_and_map_params(
self_attn.query.weight.data, f"encoder.transformer_cells.{i}.attention_cell.proj_query.weight"
)
self_attn.value.bias.data = check_and_map_params(
self_attn.value.bias.data, f"encoder.transformer_cells.{i}.attention_cell.proj_value.bias"
)
self_attn.value.weight.data = check_and_map_params(
self_attn.value.weight.data, f"encoder.transformer_cells.{i}.attention_cell.proj_value.weight"
)
# self attention output
self_output: BertSelfOutput = layer.attention.output
self_output.dense.bias = check_and_map_params(
self_output.dense.bias, f"encoder.transformer_cells.{i}.proj.bias"
)
self_output.dense.weight = check_and_map_params(
self_output.dense.weight, f"encoder.transformer_cells.{i}.proj.weight"
)
self_output.LayerNorm.bias = check_and_map_params(
self_output.LayerNorm.bias, f"encoder.transformer_cells.{i}.layer_norm.beta"
)
self_output.LayerNorm.weight = check_and_map_params(
self_output.LayerNorm.weight, f"encoder.transformer_cells.{i}.layer_norm.gamma"
)
# intermediate
intermediate: BertIntermediate = layer.intermediate
intermediate.dense.bias = check_and_map_params(
intermediate.dense.bias, f"encoder.transformer_cells.{i}.ffn.ffn_1.bias"
)
intermediate.dense.weight = check_and_map_params(
intermediate.dense.weight, f"encoder.transformer_cells.{i}.ffn.ffn_1.weight"
)
# output
bert_output: BertOutput = layer.output
bert_output.dense.bias = check_and_map_params(
bert_output.dense.bias, f"encoder.transformer_cells.{i}.ffn.ffn_2.bias"
)
bert_output.dense.weight = check_and_map_params(
bert_output.dense.weight, f"encoder.transformer_cells.{i}.ffn.ffn_2.weight"
)
bert_output.LayerNorm.bias = check_and_map_params(
bert_output.LayerNorm.bias, f"encoder.transformer_cells.{i}.ffn.layer_norm.beta"
)
bert_output.LayerNorm.weight = check_and_map_params(
bert_output.LayerNorm.weight, f"encoder.transformer_cells.{i}.ffn.layer_norm.gamma"
)
# Save space and energy 🎄
hf_bort_model.half()
# Compare output of both models
tokenizer = RobertaTokenizer.from_pretrained("FacebookAI/roberta-base")
input_ids = tokenizer.encode_plus(SAMPLE_TEXT)["input_ids"]
# Get gluon output
gluon_input_ids = mx.nd.array([input_ids])
output_gluon = original_bort(inputs=gluon_input_ids, token_types=[])
# Get Transformer output (save and reload model again)
hf_bort_model.save_pretrained(pytorch_dump_folder_path)
hf_bort_model = BertModel.from_pretrained(pytorch_dump_folder_path)
hf_bort_model.eval()
input_ids = tokenizer.encode_plus(SAMPLE_TEXT, return_tensors="pt")
output_hf = hf_bort_model(**input_ids)[0]
gluon_layer = output_gluon[0].asnumpy()
hf_layer = output_hf[0].detach().numpy()
max_absolute_diff = np.max(np.abs(hf_layer - gluon_layer)).item()
success = np.allclose(gluon_layer, hf_layer, atol=1e-3)
if success:
print("✔️ Both model do output the same tensors")
else:
print("❌ Both model do **NOT** output the same tensors")
print("Absolute difference is:", max_absolute_diff)