File size: 7,679 Bytes
d5175d3
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
# 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 torch.nn as nn
from fairseq.model_parallel.models.transformer import ModelParallelTransformerDecoder
from fairseq.models import register_model, register_model_architecture
from fairseq.models.transformer_lm import TransformerLanguageModel


try:
    from fairseq.model_parallel.megatron.mpu import VocabParallelEmbedding

    has_megatron_submodule = True
except (ImportError, ModuleNotFoundError):
    has_megatron_submodule = False


DEFAULT_MAX_TARGET_POSITIONS = 1024


@register_model("model_parallel_transformer_lm")
class ModelParallelTransformerLanguageModel(TransformerLanguageModel):

    @staticmethod
    def add_args(parser):
        TransformerLanguageModel.add_args(parser)

    @classmethod
    def build_model(cls, args, task):
        """Build a new model instance."""
        if not has_megatron_submodule:
            raise ImportError(
                "\n\nPlease install the megatron submodule:"
                "\n\n  git submodule update --init "
                "fairseq/model_parallel/megatron"
            )

        # make sure all arguments are present in older models
        base_lm_architecture(args)

        task.source_dictionary.pad_to_multiple_(args.model_parallel_size * 8)
        task.target_dictionary.pad_to_multiple_(args.model_parallel_size * 8)

        if args.decoder_layers_to_keep:
            args.decoder_layers = len(args.decoder_layers_to_keep.split(","))

        if getattr(args, "max_target_positions", None) is None:
            args.max_target_positions = getattr(
                args, "tokens_per_sample", DEFAULT_MAX_TARGET_POSITIONS
            )

        if args.character_embeddings:
            raise NotImplementedError(
                "Character embeddings is not supported for model parallel"
            )
        elif args.adaptive_input:
            raise NotImplementedError(
                "Adaptive input is not supported for model parallel"
            )
        else:
            embed_tokens = cls.build_embedding(
                args, task.source_dictionary, args.decoder_input_dim
            )

        decoder = ModelParallelTransformerDecoder(
            args,
            task.target_dictionary,
            embed_tokens,
            no_encoder_attn=True,
        )
        return cls(decoder)

    @staticmethod
    def add_args(parser):
        TransformerLanguageModel.add_args(parser)

    @classmethod
    def build_embedding(cls, args, dictionary, embed_dim, path=None):
        def _vocab_init(tensor, **kwargs):
            nn.init.normal_(tensor, mean=0, std=embed_dim ** -0.5)
            nn.init.constant_(tensor[1], 0)

        embed_tokens = VocabParallelEmbedding(
            len(dictionary), embed_dim, dictionary.pad(), init_method=_vocab_init
        )
        return embed_tokens


def base_lm_architecture(args):
    # backward compatibility for older model checkpoints
    if hasattr(args, "no_tie_adaptive_proj"):
        # previous models defined --no-tie-adaptive-proj, so use the existence of
        # that option to determine if this is an "old" model checkpoint
        args.no_decoder_final_norm = True  # old models always set this to True
        if args.no_tie_adaptive_proj is False:
            args.tie_adaptive_proj = True
    if hasattr(args, "decoder_final_norm"):
        args.no_decoder_final_norm = not args.decoder_final_norm

    args.activation_fn = getattr(args, "activation_fn", "relu")
    args.dropout = getattr(args, "dropout", 0.1)
    args.attention_dropout = getattr(args, "attention_dropout", 0.0)
    args.activation_dropout = getattr(args, "activation_dropout", 0.0)
    args.relu_dropout = getattr(args, "relu_dropout", 0.0)
    args.decoder_embed_dim = getattr(args, "decoder_embed_dim", 512)
    args.decoder_output_dim = getattr(
        args, "decoder_output_dim", args.decoder_embed_dim
    )
    args.decoder_input_dim = getattr(args, "decoder_input_dim", args.decoder_embed_dim)
    args.decoder_ffn_embed_dim = getattr(args, "decoder_ffn_embed_dim", 2048)
    args.decoder_layers = getattr(args, "decoder_layers", 6)
    args.decoder_attention_heads = getattr(args, "decoder_attention_heads", 8)
    # Model training is not stable without this
    args.decoder_normalize_before = True
    args.no_decoder_final_norm = getattr(args, "no_decoder_final_norm", False)
    args.adaptive_softmax_cutoff = getattr(args, "adaptive_softmax_cutoff", None)
    args.adaptive_softmax_dropout = getattr(args, "adaptive_softmax_dropout", 0)
    args.adaptive_softmax_factor = getattr(args, "adaptive_softmax_factor", 4)
    args.no_token_positional_embeddings = getattr(
        args, "no_token_positional_embeddings", False
    )
    args.share_decoder_input_output_embed = getattr(
        args, "share_decoder_input_output_embed", False
    )
    args.character_embeddings = getattr(args, "character_embeddings", False)
    args.character_filters = getattr(
        args,
        "character_filters",
        "[(1, 64), (2, 128), (3, 192), (4, 256), (5, 256), (6, 256), (7, 256)]",
    )
    args.character_embedding_dim = getattr(args, "character_embedding_dim", 4)
    args.char_embedder_highway_layers = getattr(args, "char_embedder_highway_layers", 2)
    args.adaptive_input = getattr(args, "adaptive_input", False)
    args.adaptive_input_factor = getattr(args, "adaptive_input_factor", 4)
    args.adaptive_input_cutoff = getattr(args, "adaptive_input_cutoff", None)
    args.tie_adaptive_weights = getattr(args, "tie_adaptive_weights", False)
    args.tie_adaptive_proj = getattr(args, "tie_adaptive_proj", False)
    args.decoder_learned_pos = getattr(args, "decoder_learned_pos", False)
    args.decoder_layerdrop = getattr(args, "decoder_layerdrop", 0.0)
    args.decoder_layers_to_keep = getattr(args, "decoder_layers_to_keep", None)
    args.layernorm_embedding = getattr(args, "layernorm_embedding", False)
    args.no_scale_embedding = getattr(args, "no_scale_embedding", False)
    args.quant_noise_pq = getattr(args, "quant_noise_pq", 0.0)
    args.quant_noise_pq_block_size = getattr(args, "quant_noise_pq_block_size", 8)
    args.quant_noise_scalar = getattr(args, "quant_noise_scalar", 0.0)
    args.add_bos_token = getattr(args, "add_bos_token", False)


@register_model_architecture("model_parallel_transformer_lm", "transformer_lm_megatron")
def transformer_lm_megatron(args):
    args.decoder_embed_dim = getattr(args, "decoder_embed_dim", 3072)
    args.decoder_ffn_embed_dim = getattr(args, "decoder_ffn_embed_dim", 3072 * 4)
    args.decoder_layers = getattr(args, "decoder_layers", 72)
    args.decoder_attention_heads = getattr(args, "decoder_attention_heads", 32)
    args.dropout = getattr(args, "dropout", 0.1)
    args.attention_dropout = getattr(args, "attention_dropout", 0.1)
    args.activation_fn = getattr(args, "activation_fn", "gelu")
    base_lm_architecture(args)


@register_model_architecture(
    "model_parallel_transformer_lm", "transformer_lm_megatron_11b"
)
def transformer_lm_megatron_11b(args):
    args.decoder_embed_dim = getattr(args, "decoder_embed_dim", 3072)
    args.decoder_ffn_embed_dim = getattr(args, "decoder_ffn_embed_dim", 3072 * 6)
    args.decoder_layers = getattr(args, "decoder_layers", 72)
    args.decoder_attention_heads = getattr(args, "decoder_attention_heads", 32)
    args.dropout = getattr(args, "dropout", 0.1)
    args.attention_dropout = getattr(args, "attention_dropout", 0.1)
    args.activation_fn = getattr(args, "activation_fn", "gelu")
    base_lm_architecture(args)