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# Copyright (c) Facebook, Inc. and its affiliates.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
import logging
import torch
import torch.nn as nn
import torch.nn.functional as F
from fairseq import utils
from fairseq.model_parallel.models.pipeline_parallel_transformer.layers import (
Embedding,
TransformerDecoderEmbedding,
TransformerDecoderLayer,
TransformerDecoderOutputLayer,
TransformerEncoderEmbedding,
TransformerEncoderLayer,
TransformerEncoderLayerNorm,
)
from fairseq.models import (
BaseFairseqModel,
FairseqDecoder,
FairseqEncoder,
register_model,
register_model_architecture,
)
from fairseq.models.fairseq_encoder import EncoderOut
from fairseq.models.transformer import (
base_architecture,
transformer_iwslt_de_en,
transformer_wmt_en_de_big,
)
from fairseq.modules import SinusoidalPositionalEmbedding
logger = logging.getLogger(__name__)
DEFAULT_MAX_SOURCE_POSITIONS = 1024
DEFAULT_MAX_TARGET_POSITIONS = 1024
TORCH_PIPE = False
RPC_INIT = False
def import_pipe():
global TORCH_PIPE
global RPC_INIT
try:
from torch.distributed.pipeline.sync import Pipe # noqa
global Pipe
from torch.distributed.pipeline.sync.utils import partition_model
global partition_model
from torch.distributed import rpc
import tempfile
TORCH_PIPE = True
# Initialize single process RPC agent since TORCH_PIPE requires
# RRef. RRef depends on RPC being initialized and as a result we initialize
# RPC with a single node.
tmpfile = tempfile.NamedTemporaryFile()
if not RPC_INIT:
rpc.init_rpc(
name="worker",
rank=0,
world_size=1,
rpc_backend_options=rpc.TensorPipeRpcBackendOptions(
init_method="file://{}".format(tmpfile.name),
)
)
RPC_INIT = True
logger.info('Using torch pipe')
except ImportError:
try:
from fairscale.nn import Pipe # noqa
logger.info('Using fairscale pipe')
except ImportError:
raise ImportError("Please install fairscale with: pip install fairscale")
@register_model("pipeline_parallel_transformer")
class PipelineParallelTransformerModel(BaseFairseqModel):
def __init__(self, encoder, decoder, balance, devices, chunks, checkpoint):
import_pipe()
super().__init__()
assert isinstance(encoder, FairseqEncoder)
assert isinstance(decoder, FairseqDecoder)
encoder_module_list = (
[encoder.embedding_layer]
+ list(encoder.encoder_layers)
+ [encoder.final_layer_norm]
)
self.num_encoder_modules = len(encoder_module_list)
decoder_module_list = (
[decoder.embedding_layer]
+ list(decoder.decoder_layers)
+ [decoder.decoder_output_layer]
)
self.num_decoder_modules = len(decoder_module_list)
module_list = encoder_module_list + decoder_module_list
self.devices = devices
if TORCH_PIPE:
self.model = Pipe(
partition_model(nn.Sequential(*module_list), balance, devices),
chunks=chunks,
checkpoint=checkpoint,
)
else:
self.model = Pipe(
nn.Sequential(*module_list),
balance=balance,
devices=devices,
chunks=chunks,
checkpoint=checkpoint,
)
self.encoder_max_positions = self.max_positions_helper(
encoder.embedding_layer, "max_source_positions"
)
self.decoder_max_positions = self.max_positions_helper(
decoder.embedding_layer, "max_target_positions"
)
self.adaptive_softmax = getattr(decoder, "adaptive_softmax", None)
# Note: To be populated during inference
self.encoder = None
self.decoder = None
def forward(self, src_tokens, src_lengths, prev_output_tokens):
if self.training:
input_lst = [src_tokens, src_lengths, prev_output_tokens]
input = tuple(i.to(self.devices[0], non_blocking=True) for i in input_lst)
if TORCH_PIPE:
return self.model(input).local_value()
else:
return self.model(input)
else:
assert self.encoder is not None and self.decoder is not None, (
"encoder and decoder need to be initialized by "
+ "calling the `prepare_for_inference_()` method"
)
encoder_output_tuple = self.encoder(input)
return self.decoder(encoder_output_tuple)
def prepare_for_inference_(self, cfg):
if self.encoder is not None and self.decoder is not None:
logger.info("Encoder and Decoder already initialized")
return
encoder_module_list = []
decoder_module_list = []
module_count = 0
for partition in self.model.partitions:
for module in partition:
if module_count < self.num_encoder_modules:
encoder_module_list.append(module)
else:
decoder_module_list.append(module)
module_count += 1
self.model = None
self.encoder = TransformerEncoder(cfg.distributed_training, None, None, encoder_module_list)
self.decoder = TransformerDecoder(
cfg.distributed_training, None, None, decoder_module_list=decoder_module_list
)
@staticmethod
def add_args(parser):
"""Add model-specific arguments to the parser."""
# fmt: off
parser.add_argument('--activation-fn',
choices=utils.get_available_activation_fns(),
help='activation function to use')
parser.add_argument('--dropout', type=float, metavar='D',
help='dropout probability')
parser.add_argument('--attention-dropout', type=float, metavar='D',
help='dropout probability for attention weights')
parser.add_argument('--activation-dropout', '--relu-dropout', type=float, metavar='D',
help='dropout probability after activation in FFN.')
parser.add_argument('--encoder-embed-path', type=str, metavar='STR',
help='path to pre-trained encoder embedding')
parser.add_argument('--encoder-embed-dim', type=int, metavar='N',
help='encoder embedding dimension')
parser.add_argument('--encoder-ffn-embed-dim', type=int, metavar='N',
help='encoder embedding dimension for FFN')
parser.add_argument('--encoder-layers', type=int, metavar='N',
help='num encoder layers')
parser.add_argument('--encoder-attention-heads', type=int, metavar='N',
help='num encoder attention heads')
parser.add_argument('--encoder-normalize-before', action='store_true',
help='apply layernorm before each encoder block')
parser.add_argument('--encoder-learned-pos', action='store_true',
help='use learned positional embeddings in the encoder')
parser.add_argument('--decoder-embed-path', type=str, metavar='STR',
help='path to pre-trained decoder embedding')
parser.add_argument('--decoder-embed-dim', type=int, metavar='N',
help='decoder embedding dimension')
parser.add_argument('--decoder-ffn-embed-dim', type=int, metavar='N',
help='decoder embedding dimension for FFN')
parser.add_argument('--decoder-layers', type=int, metavar='N',
help='num decoder layers')
parser.add_argument('--decoder-attention-heads', type=int, metavar='N',
help='num decoder attention heads')
parser.add_argument('--decoder-learned-pos', action='store_true',
help='use learned positional embeddings in the decoder')
parser.add_argument('--decoder-normalize-before', action='store_true',
help='apply layernorm before each decoder block')
parser.add_argument('--share-decoder-input-output-embed', action='store_true',
help='share decoder input and output embeddings')
parser.add_argument('--share-all-embeddings', action='store_true',
help='share encoder, decoder and output embeddings'
' (requires shared dictionary and embed dim)')
parser.add_argument('--no-token-positional-embeddings', default=False, action='store_true',
help='if set, disables positional embeddings (outside self attention)')
parser.add_argument('--adaptive-softmax-cutoff', metavar='EXPR',
help='comma separated list of adaptive softmax cutoff points. '
'Must be used with adaptive_loss criterion'),
parser.add_argument('--adaptive-softmax-dropout', type=float, metavar='D',
help='sets adaptive softmax dropout for the tail projections')
parser.add_argument('--num-embedding-chunks', type=int, metavar='N', default=1,
help='Number of embedding layer chunks (enables more even distribution'
'of optimizer states across data parallel nodes'
'when using optimizer state sharding and'
'a big embedding vocabulary)')
# fmt: on
@classmethod
def build_model_base(cls, args, task):
"""Build a new model instance."""
# make sure all arguments are present in older models
base_architecture(args)
if not hasattr(args, "max_source_positions"):
args.max_source_positions = DEFAULT_MAX_SOURCE_POSITIONS
if not hasattr(args, "max_target_positions"):
args.max_target_positions = DEFAULT_MAX_TARGET_POSITIONS
src_dict, tgt_dict = task.source_dictionary, task.target_dictionary
def build_embedding(dictionary, embed_dim, path=None, num_embed_chunks=1):
assert embed_dim % num_embed_chunks == 0, (
f"Number of embedding chunks = {num_embed_chunks} should be "
+ f"divisible by the embedding dimension = {embed_dim}"
)
assert path is None or num_embed_chunks == 1, (
"Loading embedding from a path with number of embedding chunks > 1"
+ " is not yet supported"
)
num_embeddings = len(dictionary)
padding_idx = dictionary.pad()
# if provided, load from preloaded dictionaries
if path:
emb = Embedding(num_embeddings, embed_dim, padding_idx)
embed_dict = utils.parse_embedding(path)
utils.load_embedding(embed_dict, dictionary, emb)
else:
embed_chunk_dim = embed_dim // num_embed_chunks
emb = nn.ModuleList()
for i in range(num_embed_chunks):
emb.append(Embedding(num_embeddings, embed_chunk_dim, padding_idx))
return emb
num_embed_chunks = args.num_embedding_chunks
if args.share_all_embeddings:
if src_dict != tgt_dict:
raise ValueError("--share-all-embeddings requires a joined dictionary")
if args.encoder_embed_dim != args.decoder_embed_dim:
raise ValueError(
"--share-all-embeddings requires --encoder-embed-dim to match --decoder-embed-dim"
)
if args.decoder_embed_path and (
args.decoder_embed_path != args.encoder_embed_path
):
raise ValueError(
"--share-all-embeddings not compatible with --decoder-embed-path"
)
encoder_embed_tokens = build_embedding(
src_dict,
args.encoder_embed_dim,
args.encoder_embed_path,
num_embed_chunks,
)
decoder_embed_tokens = encoder_embed_tokens
args.share_decoder_input_output_embed = True
else:
assert args.share_decoder_input_output_embed or num_embed_chunks == 1, (
"Not sharing decoder I/O embeddings is not yet supported with number of "
+ "embedding chunks > 1"
)
encoder_embed_tokens = build_embedding(
src_dict,
args.encoder_embed_dim,
args.encoder_embed_path,
num_embed_chunks,
)
decoder_embed_tokens = build_embedding(
tgt_dict,
args.decoder_embed_dim,
args.decoder_embed_path,
num_embed_chunks,
)
encoder = cls.build_encoder(args, src_dict, encoder_embed_tokens)
decoder = cls.build_decoder(args, tgt_dict, decoder_embed_tokens)
return (encoder, decoder)
@classmethod
def build_encoder(cls, args, src_dict, embed_tokens):
return TransformerEncoder(args, src_dict, embed_tokens)
@classmethod
def build_decoder(cls, args, tgt_dict, embed_tokens):
return TransformerDecoder(args, tgt_dict, embed_tokens)
@classmethod
def build_model(cls, args, task):
encoder, decoder = cls.build_model_base(args, task)
return PipelineParallelTransformerModel(
encoder=encoder,
decoder=decoder,
balance=utils.eval_str_list(args.pipeline_balance, type=int),
devices=utils.eval_str_list(args.pipeline_devices, type=int),
chunks=args.pipeline_chunks,
checkpoint=args.pipeline_checkpoint,
)
def output_layer(self, features, **kwargs):
"""Project features to the default output size (typically vocabulary size)."""
return self.decoder.output_layer(features, **kwargs)
def max_positions(self):
"""Maximum length supported by the model."""
return (self.encoder_max_positions, self.decoder_max_positions)
def max_positions_helper(
self, embedding_layer, max_positions_field="max_source_positions"
):
"""Maximum input length supported by the encoder or decoder."""
if embedding_layer.embed_positions is None:
return getattr(embedding_layer, max_positions_field)
return min(
getattr(embedding_layer, max_positions_field),
embedding_layer.embed_positions.max_positions,
)
def get_normalized_probs(self, net_output, log_probs, sample=None):
"""Get normalized probabilities (or log probs) from a net's output."""
if hasattr(self, "adaptive_softmax") and self.adaptive_softmax is not None:
if sample is not None:
assert "target" in sample
target = sample["target"]
else:
target = None
out = self.adaptive_softmax.get_log_prob(net_output, target=target)
return out.exp_() if not log_probs else out
# A Pipe() module returns a tuple of tensors as the output.
# In this case, the tuple has one element - the output tensor of logits
logits = net_output if isinstance(net_output, torch.Tensor) else net_output[0]
if log_probs:
return utils.log_softmax(logits, dim=-1, onnx_trace=False)
else:
return utils.softmax(logits, dim=-1, onnx_trace=False)
def max_decoder_positions(self):
"""Maximum length supported by the decoder."""
return self.decoder_max_positions
def load_state_dict(self, state_dict, strict=True, model_cfg=None):
"""Copies parameters and buffers from *state_dict* into this module and
its descendants.
Overrides the method in :class:`nn.Module`. Compared with that method
this additionally "upgrades" *state_dicts* from old checkpoints.
"""
self.upgrade_state_dict(state_dict)
is_regular_transformer = not any("model.partitions" in k for k in state_dict)
if is_regular_transformer:
state_dict = self.convert_to_pipeline_parallel_state_dict(state_dict)
return super().load_state_dict(state_dict, strict)
def convert_to_pipeline_parallel_state_dict(self, state_dict):
new_state_dict = self.state_dict()
encoder_layer_idx = 0
decoder_layer_idx = 0
encoder_key_suffixes = [
"self_attn.k_proj.weight",
"self_attn.k_proj.bias",
"self_attn.v_proj.weight",
"self_attn.v_proj.bias",
"self_attn.q_proj.weight",
"self_attn.q_proj.bias",
"self_attn.out_proj.weight",
"self_attn.out_proj.bias",
"self_attn_layer_norm.weight",
"self_attn_layer_norm.bias",
"fc1.weight",
"fc1.bias",
"fc2.weight",
"fc2.bias",
"final_layer_norm.weight",
"final_layer_norm.bias",
]
decoder_key_suffixes = [
"self_attn.k_proj.weight",
"self_attn.k_proj.bias",
"self_attn.v_proj.weight",
"self_attn.v_proj.bias",
"self_attn.q_proj.weight",
"self_attn.q_proj.bias",
"self_attn.out_proj.weight",
"self_attn.out_proj.bias",
"self_attn_layer_norm.weight",
"self_attn_layer_norm.bias",
"encoder_attn.k_proj.weight",
"encoder_attn.k_proj.bias",
"encoder_attn.v_proj.weight",
"encoder_attn.v_proj.bias",
"encoder_attn.q_proj.weight",
"encoder_attn.q_proj.bias",
"encoder_attn.out_proj.weight",
"encoder_attn.out_proj.bias",
"encoder_attn_layer_norm.weight",
"encoder_attn_layer_norm.bias",
"fc1.weight",
"fc1.bias",
"fc2.weight",
"fc2.bias",
"final_layer_norm.weight",
"final_layer_norm.bias",
]
for pid, partition in enumerate(self.model.partitions):
logger.info(f"Begin Partition {pid}")
for mid, module in enumerate(partition):
# fmt: off
if isinstance(module, TransformerEncoderEmbedding):
new_state_dict[f'model.partitions.{pid}.{mid}.embed_tokens.weight'] = state_dict['encoder.embed_tokens.weight']
new_state_dict[f'model.partitions.{pid}.{mid}.embed_positions._float_tensor'] = state_dict['encoder.embed_positions._float_tensor']
if isinstance(module, TransformerEncoderLayer):
for suffix in encoder_key_suffixes:
new_state_dict[f'model.partitions.{pid}.{mid}.{suffix}'] = state_dict[f'encoder.layers.{encoder_layer_idx}.{suffix}']
encoder_layer_idx += 1
if isinstance(module, TransformerDecoderLayer):
for suffix in decoder_key_suffixes:
new_state_dict[f'model.partitions.{pid}.{mid}.{suffix}'] = state_dict[f'decoder.layers.{decoder_layer_idx}.{suffix}']
decoder_layer_idx += 1
if isinstance(module, TransformerEncoderLayerNorm):
if 'encoder.layer_norm.weight' in state_dict:
new_state_dict[f'model.partitions.{pid}.{mid}.layer_norm.weight'] = state_dict['encoder.layer_norm.weight']
new_state_dict[f'model.partitions.{pid}.{mid}.layer_norm.bias'] = state_dict['encoder.layer_norm.bias']
if isinstance(module, TransformerDecoderEmbedding):
new_state_dict[f'model.partitions.{pid}.{mid}.embed_tokens.weight'] = state_dict['decoder.embed_tokens.weight']
new_state_dict[f'model.partitions.{pid}.{mid}.embed_positions._float_tensor'] = state_dict['decoder.embed_positions._float_tensor']
if isinstance(module, TransformerDecoderOutputLayer):
new_state_dict[f'model.partitions.{pid}.{mid}.output_projection.weight'] = state_dict['decoder.output_projection.weight']
# fmt: on
return new_state_dict
class TransformerEncoder(FairseqEncoder):
"""
Transformer encoder consisting of *args.encoder_layers* layers. Each layer
is a :class:`TransformerEncoderLayer`.
Args:
args (argparse.Namespace): parsed command-line arguments
dictionary (~fairseq.data.Dictionary): encoding dictionary
embed_tokens (torch.nn.Embedding): input embedding
"""
def __init__(self, args, dictionary, embed_tokens, encoder_module_list=None):
super().__init__(dictionary)
self.register_buffer("version", torch.Tensor([3]))
import_pipe()
self.use_pipeline = encoder_module_list is not None
if not self.use_pipeline:
self.embedding_layer = TransformerEncoderEmbedding(args, embed_tokens)
self.encoder_layers = nn.Sequential(*[TransformerEncoderLayer(args) for i in range(args.encoder_layers)])
if isinstance(embed_tokens, nn.ModuleList):
emb_dim = sum(e.embedding_dim for e in embed_tokens)
else:
emb_dim = embed_tokens.embedding_dim
self.final_layer_norm = TransformerEncoderLayerNorm(args, emb_dim)
else:
encoder_balance = utils.eval_str_list(
args.pipeline_encoder_balance, type=int
)
encoder_devices = utils.eval_str_list(
args.pipeline_encoder_devices, type=int
)
assert sum(encoder_balance) == len(encoder_module_list), (
f"Sum of encoder_balance={encoder_balance} is not equal "
+ f"to num_encoder_modules={len(encoder_module_list)}"
)
if TORCH_PIPE:
self.model = Pipe(
module=partition_model(nn.Sequential(*encoder_module_list), encoder_balance, encoder_devices),
chunks=args.pipeline_chunks,
checkpoint=args.pipeline_checkpoint,
)
else:
self.model = Pipe(
module=nn.Sequential(*encoder_module_list),
balance=encoder_balance,
devices=encoder_devices,
chunks=args.pipeline_chunks,
checkpoint=args.pipeline_checkpoint,
)
def forward(self, src_tokens, src_lengths):
"""
Args:
input_tuple(
src_tokens (LongTensor): tokens in the source language of shape
`(batch, src_len)`
src_lengths (torch.LongTensor): lengths of each source sentence of
shape `(batch)`
)
Returns:
output_tuple(
- **encoder_out** (Tensor): the last encoder layer's output of
shape `(src_len, batch, embed_dim)`
- **encoder_padding_mask** (ByteTensor): the positions of
padding elements of shape `(batch, src_len)`
- prev_output_tokens
- **encoder_states** (List[Tensor]): all intermediate
hidden states of shape `(src_len, batch, embed_dim)`.
Only populated if *return_all_hiddens* is True.
)
"""
dummy_prev_output_tokens = torch.zeros(
1, dtype=src_tokens.dtype, device=src_tokens.device
)
input_tuple = (src_tokens, src_lengths, dummy_prev_output_tokens)
if self.use_pipeline:
input_tuple = tuple(i.to(self.model.devices[0]) for i in input_tuple)
if TORCH_PIPE:
encoder_out = self.model(input_tuple).local_value()
else:
encoder_out = self.model(input_tuple)
else:
encoder_embed_output_tuple = self.embedding_layer(input_tuple)
encoder_layers_output = self.encoder_layers(encoder_embed_output_tuple)
encoder_out = self.final_layer_norm(encoder_layers_output)
# first element is the encoder output
# second element is the encoder padding mask
# the remaining elements of EncoderOut are not computed by
# the PipelineParallelTransformer
return EncoderOut(encoder_out[0], encoder_out[1], None, None, None, None)
def reorder_encoder_out(self, encoder_out, new_order):
"""
Reorder encoder output according to *new_order*.
Args:
encoder_out: output from the ``forward()`` method
new_order (LongTensor): desired order
Returns:
*encoder_out* rearranged according to *new_order*
"""
if encoder_out.encoder_out is not None:
encoder_out = encoder_out._replace(
encoder_out=encoder_out.encoder_out.index_select(1, new_order)
)
if encoder_out.encoder_padding_mask is not None:
encoder_out = encoder_out._replace(
encoder_padding_mask=encoder_out.encoder_padding_mask.index_select(
0, new_order
)
)
if encoder_out.encoder_embedding is not None:
encoder_out = encoder_out._replace(
encoder_embedding=encoder_out.encoder_embedding.index_select(
0, new_order
)
)
if encoder_out.encoder_states is not None:
for idx, state in enumerate(encoder_out.encoder_states):
encoder_out.encoder_states[idx] = state.index_select(1, new_order)
return encoder_out
def max_positions(self):
"""Maximum input length supported by the encoder."""
if self.embedding_layer.embed_positions is None:
return self.embedding_layer.max_source_positions
return min(
self.embedding_layer.max_source_positions,
self.embedding_layer.embed_positions.max_positions,
)
class TransformerDecoder(FairseqDecoder):
"""
Transformer decoder consisting of *args.decoder_layers* layers. Each layer
is a :class:`TransformerDecoderLayer`.
Args:
args (argparse.Namespace): parsed command-line arguments
dictionary (~fairseq.data.Dictionary): decoding dictionary
embed_tokens (torch.nn.Embedding): output embedding
no_encoder_attn (bool, optional): whether to attend to encoder outputs
(default: False).
"""
def __init__(
self,
args,
dictionary,
embed_tokens,
no_encoder_attn=False,
decoder_module_list=None,
):
super().__init__(dictionary)
self.register_buffer("version", torch.Tensor([3]))
import_pipe()
self.use_pipeline = decoder_module_list is not None
if not self.use_pipeline:
self.embedding_layer = TransformerDecoderEmbedding(args, embed_tokens)
self.decoder_layers = nn.Sequential(*[
TransformerDecoderLayer(args, no_encoder_attn)
for _ in range(args.decoder_layers)
])
self.decoder_output_layer = TransformerDecoderOutputLayer(
args, embed_tokens, dictionary
)
else:
decoder_balance = utils.eval_str_list(
args.pipeline_decoder_balance, type=int
)
decoder_devices = utils.eval_str_list(
args.pipeline_decoder_devices, type=int
)
assert sum(decoder_balance) == len(decoder_module_list), (
f"Sum of decoder_balance={decoder_balance} is not equal "
+ f"to num_decoder_modules={len(decoder_module_list)}"
)
if TORCH_PIPE:
self.model = Pipe(
module=partition_model(nn.Sequential(*decoder_module_list), decoder_balance, decoder_devices),
chunks=args.pipeline_chunks,
checkpoint=args.pipeline_checkpoint,
)
else:
self.model = Pipe(
module=nn.Sequential(*decoder_module_list),
balance=decoder_balance,
devices=decoder_devices,
chunks=args.pipeline_chunks,
checkpoint=args.pipeline_checkpoint,
)
def forward(
self,
prev_output_tokens,
encoder_out=None,
):
"""
Args:
prev_output_tokens (LongTensor): previous decoder outputs of shape
`(batch, tgt_len)`, for teacher forcing
encoder_out (optional): output from the encoder, used for
encoder-side attention
incremental_state (dict): dictionary used for storing state during
:ref:`Incremental decoding`
features_only (bool, optional): only return features without
applying output layer (default: False).
Returns:
tuple:
- the decoder's output of shape `(batch, tgt_len, vocab)`
- a dictionary with any model-specific outputs
"""
input_tuple = (
encoder_out.encoder_out,
encoder_out.encoder_padding_mask,
prev_output_tokens,
)
if self.use_pipeline:
input_tuple = tuple(i.to(self.model.devices[0]) for i in input_tuple)
if TORCH_PIPE:
return (self.model(input_tuple).local_value(),)
else:
return (self.model(input_tuple),)
else:
embed_layer_output = self.embedding_layer(input_tuple)
state = self.decoder_layers(embed_layer_output)
return (self.decoder_output_layer(state),)
def output_layer(self, features, **kwargs):
"""Project features to the vocabulary size."""
if self.adaptive_softmax is None:
# project back to size of vocabulary
if self.share_input_output_embed:
return F.linear(features, self.embed_tokens.weight)
else:
return F.linear(features, self.embed_out)
else:
return features
def max_positions(self):
"""Maximum output length supported by the decoder."""
if self.embedding_layer.embed_positions is None:
return self.embedding_layer.max_target_positions
return min(
self.embedding_layer.max_target_positions,
self.embedding_layer.embed_positions.max_positions,
)
def buffered_future_mask(self, tensor):
dim = tensor.size(0)
if (
not hasattr(self, "_future_mask")
or self._future_mask is None
or self._future_mask.device != tensor.device
or self._future_mask.size(0) < dim
):
self._future_mask = torch.triu(
utils.fill_with_neg_inf(tensor.new(dim, dim)), 1
)
return self._future_mask[:dim, :dim]
def upgrade_state_dict_named(self, state_dict, name):
"""Upgrade a (possibly old) state dict for new versions of fairseq."""
if isinstance(self.embed_positions, SinusoidalPositionalEmbedding):
weights_key = "{}.embed_positions.weights".format(name)
if weights_key in state_dict:
del state_dict[weights_key]
state_dict[
"{}.embed_positions._float_tensor".format(name)
] = torch.FloatTensor(1)
for i in range(len(self.layers)):
# update layer norms
layer_norm_map = {
"0": "self_attn_layer_norm",
"1": "encoder_attn_layer_norm",
"2": "final_layer_norm",
}
for old, new in layer_norm_map.items():
for m in ("weight", "bias"):
k = "{}.layers.{}.layer_norms.{}.{}".format(name, i, old, m)
if k in state_dict:
state_dict[
"{}.layers.{}.{}.{}".format(name, i, new, m)
] = state_dict[k]
del state_dict[k]
version_key = "{}.version".format(name)
if utils.item(state_dict.get(version_key, torch.Tensor([1]))[0]) <= 2:
# earlier checkpoints did not normalize after the stack of layers
self.layer_norm = None
self.normalize = False
state_dict[version_key] = torch.Tensor([1])
return state_dict
@register_model_architecture(
"pipeline_parallel_transformer", "transformer_iwslt_de_en_pipeline_parallel"
)
def transformer_iwslt_de_en_dist(args):
transformer_iwslt_de_en(args)
@register_model_architecture(
"pipeline_parallel_transformer", "transformer_wmt_en_de_big_pipeline_parallel"
)
def transformer_wmt_en_de_big_dist(args):
transformer_wmt_en_de_big(args)
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