Text Generation
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llama
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text-generation-inference
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Delete modeling_flash_llama.py

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- # coding=utf-8
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- # From https://huggingface.co/togethercomputer/LLaMA-2-7B-32K/blob/main/modeling_flash_llama.py
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- # With fix from Alex Birch: https://huggingface.co/togethercomputer/LLaMA-2-7B-32K/discussions/17
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- # Copyright 2022 EleutherAI and the HuggingFace Inc. team. All rights reserved.
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- #
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- # This code is based on EleutherAI's GPT-NeoX library and the GPT-NeoX
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- # and OPT implementations in this library. It has been modified from its
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- # original forms to accommodate minor architectural differences compared
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- # to GPT-NeoX and OPT used by the Meta AI team that trained the model.
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- #
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- # Licensed under the Apache License, Version 2.0 (the "License");
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- # you may not use this file except in compliance with the License.
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- # You may obtain a copy of the License at
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- #
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- # http://www.apache.org/licenses/LICENSE-2.0
16
- #
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- # Unless required by applicable law or agreed to in writing, software
18
- # distributed under the License is distributed on an "AS IS" BASIS,
19
- # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
20
- # See the License for the specific language governing permissions and
21
- # limitations under the License.
22
- """ PyTorch LLaMA model."""
23
- from typing import List, Optional, Tuple, Union
24
-
25
- import torch
26
- import torch.nn.functional as F
27
- import torch.utils.checkpoint
28
- from torch import nn
29
- from torch.nn import BCEWithLogitsLoss, CrossEntropyLoss, MSELoss
30
-
31
- from transformers.activations import ACT2FN
32
- from transformers.modeling_outputs import BaseModelOutputWithPast, CausalLMOutputWithPast, SequenceClassifierOutputWithPast
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- from transformers.modeling_utils import PreTrainedModel
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- from transformers.utils import add_start_docstrings, add_start_docstrings_to_model_forward, logging, replace_return_docstrings
35
- from transformers.models.llama.configuration_llama import LlamaConfig
36
-
37
-
38
- try:
39
- from flash_attn.flash_attn_interface import (
40
- flash_attn_kvpacked_func,
41
- flash_attn_varlen_kvpacked_func,
42
- )
43
- from flash_attn.bert_padding import unpad_input, pad_input
44
- flash_attn_v2_installed = True
45
- print('>>>> Flash Attention installed')
46
- except ImportError:
47
- flash_attn_v2_installed = False
48
- raise ImportError('Please install Flash Attention: `pip install flash-attn --no-build-isolation`')
49
-
50
- try:
51
- from flash_attn.layers.rotary import apply_rotary_emb_func
52
- flash_rope_installed = True
53
- print('>>>> Flash RoPE installed')
54
- except ImportError:
55
- flash_rope_installed = False
56
- raise ImportError('Please install RoPE kernels: `pip install git+https://github.com/HazyResearch/flash-attention.git#subdirectory=csrc/rotary`')
57
-
58
-
59
- logger = logging.get_logger(__name__)
60
-
61
- _CONFIG_FOR_DOC = "LlamaConfig"
62
-
63
-
64
- # @torch.jit.script
65
- def rmsnorm_func(hidden_states, weight, variance_epsilon):
66
- input_dtype = hidden_states.dtype
67
- hidden_states = hidden_states.to(torch.float32)
68
- variance = hidden_states.pow(2).mean(-1, keepdim=True)
69
- hidden_states = hidden_states * torch.rsqrt(variance + variance_epsilon)
70
- return (weight * hidden_states).to(input_dtype)
71
-
72
-
73
- class LlamaRMSNorm(nn.Module):
74
- def __init__(self, hidden_size, eps=1e-6):
75
- """
76
- LlamaRMSNorm is equivalent to T5LayerNorm
77
- """
78
- super().__init__()
79
- self.weight = nn.Parameter(torch.ones(hidden_size))
80
- self.register_buffer(
81
- "variance_epsilon",
82
- torch.tensor(eps),
83
- persistent=False,
84
- )
85
-
86
- def forward(self, hidden_states):
87
- return rmsnorm_func(hidden_states, self.weight, self.variance_epsilon)
88
-
89
-
90
- class FlashRotaryEmbedding(torch.nn.Module):
91
- """
92
- The rotary position embeddings from RoFormer_ (Su et. al).
93
- A crucial insight from the method is that the query and keys are
94
- transformed by rotation matrices which depend on the relative positions.
95
-
96
- Other implementations are available in the Rotary Transformer repo_ and in
97
- GPT-NeoX_, GPT-NeoX was an inspiration
98
-
99
- .. _RoFormer: https://arxiv.org/abs/2104.09864
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- .. _repo: https://github.com/ZhuiyiTechnology/roformer
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- .. _GPT-NeoX: https://github.com/EleutherAI/gpt-neox
102
-
103
- If scale_base is not None, this implements XPos (Sun et al., https://arxiv.org/abs/2212.10554).
104
- A recommended value for scale_base is 512: https://github.com/HazyResearch/flash-attention/issues/96
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- Reference: https://github.com/sunyt32/torchscale/blob/main/torchscale/component/xpos_relative_position.py
106
- """
107
-
108
- def __init__(self, dim: int, base=10000.0, interleaved=False, scale_base=None,
109
- scaling_factor=1.0, pos_idx_in_fp32=True, device=None):
110
- """
111
- interleaved: if True, rotate pairs of even and odd dimensions (GPT-J style) instead
112
- of 1st half and 2nd half (GPT-NeoX style).
113
- pos_idx_in_fp32: if True, the position indices [0.0, ..., seqlen - 1] are in fp32,
114
- otherwise they might be in lower precision.
115
- This option was added because previously (before 2023-07-02), when we construct
116
- the position indices, we use the dtype of self.inv_freq. In most cases this would
117
- be fp32, but if the model is trained in pure bf16 (not mixed precision), then
118
- self.inv_freq would be bf16, and the position indices are also in bf16.
119
- Because of the limited precision of bf16 (e.g. 1995.0 is rounded to 2000.0), the
120
- embeddings for some positions will coincide.
121
- To maintain compatibility with models previously trained in pure bf16,
122
- we add this option.
123
- scaling_factor: RotaryEmbedding extended with linear scaling.
124
- """
125
- super().__init__()
126
- self.dim = dim
127
- self.base = float(base)
128
- self.pos_idx_in_fp32 = pos_idx_in_fp32
129
- # Generate and save the inverse frequency buffer (non trainable)
130
- inv_freq = self._compute_inv_freq(device)
131
- self.register_buffer("inv_freq", inv_freq, persistent=False)
132
- self.interleaved = interleaved
133
- self.scale_base = scale_base
134
- self.scaling_factor = scaling_factor
135
- scale = ((torch.arange(0, dim, 2, device=device, dtype=torch.float32) + 0.4 * dim)
136
- / (1.4 * dim) if scale_base is not None else None)
137
- self.register_buffer("scale", scale)
138
-
139
- self._seq_len_cached = 0
140
- self._cos_cached = None
141
- self._sin_cached = None
142
- self._cos_k_cached = None
143
- self._sin_k_cached = None
144
-
145
- def _compute_inv_freq(self, device=None):
146
- return 1 / (self.base ** (torch.arange(0, self.dim, 2, device=device,
147
- dtype=torch.float32) / self.dim))
148
-
149
-
150
- def _update_cos_sin_cache(self, seqlen, device=None, dtype=None):
151
- # Reset the tables if the sequence length has changed,
152
- # if we're on a new device (possibly due to tracing for instance),
153
- # or if we're switching from inference mode to training
154
- if (seqlen > self._seq_len_cached or self._cos_cached.device != device
155
- or self._cos_cached.dtype != dtype
156
- or (self.training and self._cos_cached.is_inference())):
157
- self._seq_len_cached = seqlen
158
- # We want fp32 here, not self.inv_freq.dtype, since the model could be loaded in bf16
159
- # And the output of arange can be quite large, so bf16 would lose a lot of precision.
160
- # However, for compatibility reason, we add an option to use the dtype of self.inv_freq.
161
- if self.pos_idx_in_fp32:
162
- t = torch.arange(seqlen, device=device, dtype=torch.float32)
163
- t /= self.scaling_factor
164
- # We want fp32 here as well since inv_freq will be multiplied with t, and the output
165
- # will be large. Having it in bf16 will lose a lot of precision and cause the
166
- # cos & sin output to change significantly.
167
- # We want to recompute self.inv_freq if it was not loaded in fp32
168
- if self.inv_freq.dtype != torch.float32:
169
- inv_freq = self.inv_freq.to(torch.float32)
170
- else:
171
- inv_freq = self.inv_freq
172
- else:
173
- t = torch.arange(seqlen, device=device, dtype=self.inv_freq.dtype)
174
- t /= self.scaling_factor
175
- inv_freq = self.inv_freq
176
- # Don't do einsum, it converts fp32 to fp16 under AMP
177
- # freqs = torch.einsum("i,j->ij", t, self.inv_freq)
178
- freqs = torch.outer(t, inv_freq)
179
- if self.scale is None:
180
- self._cos_cached = torch.cos(freqs).to(dtype)
181
- self._sin_cached = torch.sin(freqs).to(dtype)
182
- else:
183
- power = ((torch.arange(seqlen, dtype=self.scale.dtype, device=self.scale.device)
184
- - seqlen // 2) / self.scale_base)
185
- scale = self.scale.to(device=power.device) ** power.unsqueeze(-1)
186
- # We want the multiplication by scale to happen in fp32
187
- self._cos_cached = (torch.cos(freqs) * scale).to(dtype)
188
- self._sin_cached = (torch.sin(freqs) * scale).to(dtype)
189
- self._cos_k_cached = (torch.cos(freqs) / scale).to(dtype)
190
- self._sin_k_cached = (torch.sin(freqs) / scale).to(dtype)
191
-
192
- def forward(self, q: torch.Tensor, k: torch.Tensor, seqlen_offset: int = 0) -> Tuple[torch.Tensor, torch.Tensor]:
193
- """
194
- q: (batch, seqlen, nheads, headdim)
195
- k: (batch, seqlen, nheads, headdim)
196
- seqlen_offset: can be used in generation where the qkv being passed in is only the last
197
- token in the batch.
198
- """
199
- self._update_cos_sin_cache(q.shape[1] + seqlen_offset, device=q.device, dtype=q.dtype)
200
- if self.scale is None:
201
- return apply_rotary_emb_func(
202
- q, self._cos_cached[seqlen_offset:], self._sin_cached[seqlen_offset:],
203
- self.interleaved, True # inplace=True
204
- ), apply_rotary_emb_func(
205
- k, self._cos_cached[seqlen_offset:], self._sin_cached[seqlen_offset:],
206
- self.interleaved, True # inplace=True
207
- )
208
- else:
209
- assert False
210
-
211
- class LlamaMLP(nn.Module):
212
- def __init__(self, config):
213
- super().__init__()
214
- self.config = config
215
- self.hidden_size = config.hidden_size
216
- self.intermediate_size = config.intermediate_size
217
- self.gate_proj = nn.Linear(self.hidden_size, self.intermediate_size, bias=False)
218
- self.up_proj = nn.Linear(self.hidden_size, self.intermediate_size, bias=False)
219
- self.down_proj = nn.Linear(self.intermediate_size, self.hidden_size, bias=False)
220
- self.act_fn = ACT2FN[config.hidden_act]
221
-
222
- def forward(self, x):
223
- if self.config.pretraining_tp > 1:
224
- slice = self.intermediate_size // self.config.pretraining_tp
225
- gate_proj_slices = self.gate_proj.weight.split(slice, dim=0)
226
- up_proj_slices = self.up_proj.weight.split(slice, dim=0)
227
- down_proj_slices = self.down_proj.weight.split(slice, dim=1)
228
-
229
- gate_proj = torch.cat(
230
- [F.linear(x, gate_proj_slices[i]) for i in range(self.config.pretraining_tp)], dim=-1
231
- )
232
- up_proj = torch.cat([F.linear(x, up_proj_slices[i]) for i in range(self.config.pretraining_tp)], dim=-1)
233
-
234
- intermediate_states = (self.act_fn(gate_proj) * up_proj).split(slice, dim=2)
235
- down_proj = [
236
- F.linear(intermediate_states[i], down_proj_slices[i]) for i in range(self.config.pretraining_tp)
237
- ]
238
- down_proj = sum(down_proj)
239
- else:
240
- down_proj = self.down_proj(self.act_fn(self.gate_proj(x)) * self.up_proj(x))
241
-
242
- return down_proj
243
-
244
- @torch.jit.script
245
- def repeat_kv(hidden_states: torch.Tensor, n_rep: int) -> torch.Tensor:
246
- """
247
- This is the equivalent of torch.repeat_interleave(x, dim=1, repeats=n_rep). The hidden states go from (batch,
248
- num_key_value_heads, seqlen, head_dim) to (batch, num_attention_heads, seqlen, head_dim)
249
- """
250
- batch, slen, _, num_key_value_heads, head_dim = hidden_states.shape
251
- if n_rep == 1:
252
- return hidden_states
253
- hidden_states = hidden_states[:, :, :, :, None, :].expand(batch, slen, 2, num_key_value_heads, n_rep, head_dim)
254
- return hidden_states.reshape(batch, slen, 2, num_key_value_heads * n_rep, head_dim)
255
-
256
-
257
- class LlamaAttention(nn.Module):
258
- """Multi-headed attention from 'Attention Is All You Need' paper"""
259
-
260
- def __init__(self, config: LlamaConfig):
261
- super().__init__()
262
- self.config = config
263
- self.hidden_size = config.hidden_size
264
- self.num_heads = config.num_attention_heads
265
- self.head_dim = self.hidden_size // self.num_heads
266
- self.num_key_value_heads = config.num_key_value_heads
267
- self.num_key_value_groups = self.num_heads // self.num_key_value_heads
268
- self.max_position_embeddings = config.max_position_embeddings
269
-
270
- if (self.head_dim * self.num_heads) != self.hidden_size:
271
- raise ValueError(
272
- f"hidden_size must be divisible by num_heads (got `hidden_size`: {self.hidden_size}"
273
- f" and `num_heads`: {self.num_heads})."
274
- )
275
- self.q_proj = nn.Linear(self.hidden_size, self.num_heads * self.head_dim, bias=False)
276
- self.k_proj = nn.Linear(self.hidden_size, self.num_key_value_heads * self.head_dim, bias=False)
277
- self.v_proj = nn.Linear(self.hidden_size, self.num_key_value_heads * self.head_dim, bias=False)
278
- self.o_proj = nn.Linear(self.num_heads * self.head_dim, self.hidden_size, bias=False)
279
-
280
- self.register_buffer(
281
- "norm_factor",
282
- torch.sqrt(torch.tensor(self.head_dim, dtype=torch.float32)).to(torch.get_default_dtype()),
283
- persistent=False,
284
- )
285
-
286
- if self.config.rope_scaling is None:
287
- scaling_factor = 1
288
- else:
289
- scaling_type = self.config.rope_scaling["type"]
290
- scaling_factor = self.config.rope_scaling["factor"]
291
- assert scaling_type == 'linear'
292
-
293
- self.rotary_emb = FlashRotaryEmbedding(
294
- self.head_dim, base=10000, interleaved=False, scaling_factor=scaling_factor,
295
- )
296
-
297
- def _shape(self, tensor: torch.Tensor, seq_len: int, bsz: int):
298
- return tensor.view(bsz, seq_len, self.num_heads, self.head_dim).transpose(1, 2).contiguous()
299
-
300
- def forward(
301
- self,
302
- hidden_states: torch.Tensor,
303
- attention_mask: Optional[torch.Tensor] = None,
304
- position_ids: Optional[torch.LongTensor] = None,
305
- past_key_value: Optional[Tuple[torch.Tensor]] = None,
306
- output_attentions: bool = False,
307
- use_cache: bool = False,
308
- is_padded_inputs: Optional[bool] = False,
309
- ) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor]]]:
310
- bsz, q_len, h_size = hidden_states.size()
311
-
312
- has_layer_past = past_key_value is not None
313
-
314
- if has_layer_past:
315
- past_kv = past_key_value[0]
316
- past_len = past_key_value[1]
317
- else:
318
- past_len = 0
319
-
320
- if self.config.pretraining_tp > 1:
321
- key_value_slicing = (self.num_key_value_heads * self.head_dim) // self.config.pretraining_tp
322
- query_slices = self.q_proj.weight.split(
323
- (self.num_heads * self.head_dim) // self.config.pretraining_tp, dim=0
324
- )
325
- key_slices = self.k_proj.weight.split(key_value_slicing, dim=0)
326
- value_slices = self.v_proj.weight.split(key_value_slicing, dim=0)
327
-
328
- q = [F.linear(hidden_states, query_slices[i]) for i in range(self.config.pretraining_tp)]
329
- q = torch.cat(q, dim=-1)
330
-
331
- k = [F.linear(hidden_states, key_slices[i]) for i in range(self.config.pretraining_tp)]
332
- k = torch.cat(k, dim=-1)
333
-
334
- v = [F.linear(hidden_states, value_slices[i]) for i in range(self.config.pretraining_tp)]
335
- v = torch.cat(v, dim=-1)
336
-
337
- else:
338
- q = self.q_proj(hidden_states)
339
- k = self.k_proj(hidden_states)
340
- v = self.v_proj(hidden_states)
341
-
342
- q = q.view(bsz, q_len, self.num_heads, self.head_dim)
343
- k = k.view(bsz, q_len, self.num_key_value_heads, self.head_dim)
344
- v = v.view(bsz, q_len, self.num_key_value_heads, self.head_dim)
345
-
346
- q, k = self.rotary_emb(q, k, past_len)
347
-
348
- kv = torch.stack([k, v], 2)
349
- kv = repeat_kv(kv, self.num_key_value_groups)
350
-
351
- # Cache QKV values
352
- if has_layer_past:
353
- new_len = past_len+q.size(1)
354
- if new_len > past_kv.size(1):
355
- past_kv = torch.cat([past_kv, torch.empty(bsz, 256, 2, kv.size(3), kv.size(4), dtype=kv.dtype, device=kv.device)], 1)
356
- past_kv[:, past_len:new_len] = kv
357
- kv = past_kv[:, :new_len]
358
- else:
359
- past_kv = kv
360
-
361
- past_key_value = (past_kv, past_len+q.size(1)) if use_cache else None
362
-
363
- if is_padded_inputs:
364
-
365
- # varlen, ignore padding tokens, efficient for large batch with many paddings
366
-
367
- assert attention_mask is not None
368
-
369
- unpadded_kv, indices_k, cu_seqlens_k, max_seqlen_k = unpad_input(kv, attention_mask)
370
- unpadded_q, indices_q, cu_seqlens_q, max_seqlen_q = unpad_input(q, attention_mask[:, -q.size(1):])
371
- attn_outputs = flash_attn_varlen_kvpacked_func(
372
- unpadded_q, unpadded_kv, cu_seqlens_q, cu_seqlens_k,
373
- max_seqlen_q, max_seqlen_k,
374
- dropout_p=0.0, softmax_scale=1.0/self.norm_factor,
375
- causal=(not has_layer_past), return_attn_probs=output_attentions
376
- )
377
-
378
- attn_output = attn_outputs[0] if output_attentions else attn_outputs
379
- attn_output = pad_input(
380
- attn_output, indices_q, bsz, q_len
381
- ).reshape(bsz, q_len, h_size)
382
- attn_weights = attn_outputs[2] if output_attentions else None
383
-
384
- else:
385
-
386
- # no padding tokens, more efficient
387
-
388
- attn_outputs = flash_attn_kvpacked_func(
389
- q, kv, dropout_p=0.0, softmax_scale=1.0/self.norm_factor, causal=(not has_layer_past), return_attn_probs=output_attentions)
390
-
391
- attn_output = attn_outputs[0] if output_attentions else attn_outputs
392
- attn_output = attn_output.reshape(bsz, q_len, h_size)
393
- attn_weights = attn_outputs[2] if output_attentions else None
394
-
395
- if self.config.pretraining_tp > 1:
396
- attn_output = attn_output.split(self.hidden_size // self.config.pretraining_tp, dim=2)
397
- o_proj_slices = self.o_proj.weight.split(self.hidden_size // self.config.pretraining_tp, dim=1)
398
- attn_output = sum([F.linear(attn_output[i], o_proj_slices[i]) for i in range(self.config.pretraining_tp)])
399
- else:
400
- attn_output = self.o_proj(attn_output)
401
-
402
- if not output_attentions:
403
- attn_weights = None
404
-
405
- return attn_output, attn_weights, past_key_value
406
-
407
-
408
- class LlamaDecoderLayer(nn.Module):
409
- def __init__(self, config: LlamaConfig):
410
- super().__init__()
411
- self.hidden_size = config.hidden_size
412
- self.self_attn = LlamaAttention(config=config)
413
- self.mlp = LlamaMLP(config)
414
- self.input_layernorm = LlamaRMSNorm(config.hidden_size, eps=config.rms_norm_eps)
415
- self.post_attention_layernorm = LlamaRMSNorm(config.hidden_size, eps=config.rms_norm_eps)
416
-
417
- def forward(
418
- self,
419
- hidden_states: torch.Tensor,
420
- attention_mask: Optional[torch.Tensor] = None,
421
- position_ids: Optional[torch.LongTensor] = None,
422
- past_key_value: Optional[Tuple[torch.Tensor]] = None,
423
- is_padded_inputs: Optional[bool] = False,
424
- output_attentions: Optional[bool] = False,
425
- use_cache: Optional[bool] = False,
426
- ) -> Tuple[torch.FloatTensor, Optional[Tuple[torch.FloatTensor, torch.FloatTensor]]]:
427
- """
428
- Args:
429
- hidden_states (`torch.FloatTensor`): input to the layer of shape `(batch, seq_len, embed_dim)`
430
- attention_mask (`torch.FloatTensor`, *optional*): attention mask of size
431
- `(batch, 1, tgt_len, src_len)` where padding elements are indicated by very large negative values.
432
- output_attentions (`bool`, *optional*):
433
- Whether or not to return the attentions tensors of all attention layers. See `attentions` under
434
- returned tensors for more detail.
435
- use_cache (`bool`, *optional*):
436
- If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding
437
- (see `past_key_values`).
438
- past_key_value (`Tuple(torch.FloatTensor)`, *optional*): cached past key and value projection states
439
- """
440
-
441
- residual = hidden_states
442
-
443
- hidden_states = self.input_layernorm(hidden_states)
444
-
445
- # Self Attention
446
- hidden_states, self_attn_weights, present_key_value = self.self_attn(
447
- hidden_states=hidden_states,
448
- attention_mask=attention_mask,
449
- position_ids=position_ids,
450
- past_key_value=past_key_value,
451
- output_attentions=output_attentions,
452
- use_cache=use_cache,
453
- is_padded_inputs=is_padded_inputs,
454
- )
455
- hidden_states = residual + hidden_states
456
-
457
- # Fully Connected
458
- residual = hidden_states
459
- hidden_states = self.post_attention_layernorm(hidden_states)
460
- hidden_states = self.mlp(hidden_states)
461
- hidden_states = residual + hidden_states
462
-
463
- outputs = (hidden_states,)
464
-
465
- if output_attentions:
466
- outputs += (self_attn_weights,)
467
-
468
- if use_cache:
469
- outputs += (present_key_value,)
470
-
471
- return outputs
472
-
473
-
474
- LLAMA_START_DOCSTRING = r"""
475
- This model inherits from [`PreTrainedModel`]. Check the superclass documentation for the generic methods the
476
- library implements for all its model (such as downloading or saving, resizing the input embeddings, pruning heads
477
- etc.)
478
-
479
- This model is also a PyTorch [torch.nn.Module](https://pytorch.org/docs/stable/nn.html#torch.nn.Module) subclass.
480
- Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage
481
- and behavior.
482
-
483
- Parameters:
484
- config ([`LlamaConfig`]):
485
- Model configuration class with all the parameters of the model. Initializing with a config file does not
486
- load the weights associated with the model, only the configuration. Check out the
487
- [`~PreTrainedModel.from_pretrained`] method to load the model weights.
488
- """
489
-
490
-
491
- @add_start_docstrings(
492
- "The bare LLaMA Model outputting raw hidden-states without any specific head on top.",
493
- LLAMA_START_DOCSTRING,
494
- )
495
- class LlamaPreTrainedModel(PreTrainedModel):
496
- config_class = LlamaConfig
497
- base_model_prefix = "model"
498
- supports_gradient_checkpointing = True
499
- _no_split_modules = ["LlamaDecoderLayer"]
500
- _skip_keys_device_placement = "past_key_values"
501
-
502
- def _init_weights(self, module):
503
- std = self.config.initializer_range
504
- if isinstance(module, nn.Linear):
505
- module.weight.data.normal_(mean=0.0, std=std)
506
- if module.bias is not None:
507
- module.bias.data.zero_()
508
- elif isinstance(module, nn.Embedding):
509
- module.weight.data.normal_(mean=0.0, std=std)
510
- if module.padding_idx is not None:
511
- module.weight.data[module.padding_idx].zero_()
512
-
513
- def _set_gradient_checkpointing(self, module, value=False):
514
- if isinstance(module, LlamaModel):
515
- module.gradient_checkpointing = value
516
-
517
-
518
- LLAMA_INPUTS_DOCSTRING = r"""
519
- Args:
520
- input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`):
521
- Indices of input sequence tokens in the vocabulary. Padding will be ignored by default should you provide
522
- it.
523
-
524
- Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
525
- [`PreTrainedTokenizer.__call__`] for details.
526
-
527
- [What are input IDs?](../glossary#input-ids)
528
- attention_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
529
- Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`:
530
-
531
- - 1 for tokens that are **not masked**,
532
- - 0 for tokens that are **masked**.
533
-
534
- [What are attention masks?](../glossary#attention-mask)
535
-
536
- Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
537
- [`PreTrainedTokenizer.__call__`] for details.
538
-
539
- If `past_key_values` is used, optionally only the last `decoder_input_ids` have to be input (see
540
- `past_key_values`).
541
-
542
- If you want to change padding behavior, you should read [`modeling_opt._prepare_decoder_attention_mask`]
543
- and modify to your needs. See diagram 1 in [the paper](https://arxiv.org/abs/1910.13461) for more
544
- information on the default strategy.
545
-
546
- - 1 indicates the head is **not masked**,
547
- - 0 indicates the head is **masked**.
548
- position_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
549
- Indices of positions of each input sequence tokens in the position embeddings. Selected in the range `[0,
550
- config.n_positions - 1]`.
551
-
552
- [What are position IDs?](../glossary#position-ids)
553
- past_key_values (`tuple(tuple(torch.FloatTensor))`, *optional*, returned when `use_cache=True` is passed or when `config.use_cache=True`):
554
- Tuple of `tuple(torch.FloatTensor)` of length `config.n_layers`, with each tuple having 2 tensors of shape
555
- `(batch_size, num_heads, sequence_length, embed_size_per_head)`) and 2 additional tensors of shape
556
- `(batch_size, num_heads, encoder_sequence_length, embed_size_per_head)`.
557
-
558
- Contains pre-computed hidden-states (key and values in the self-attention blocks and in the cross-attention
559
- blocks) that can be used (see `past_key_values` input) to speed up sequential decoding.
560
-
561
- If `past_key_values` are used, the user can optionally input only the last `decoder_input_ids` (those that
562
- don't have their past key value states given to this model) of shape `(batch_size, 1)` instead of all
563
- `decoder_input_ids` of shape `(batch_size, sequence_length)`.
564
- inputs_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`, *optional*):
565
- Optionally, instead of passing `input_ids` you can choose to directly pass an embedded representation. This
566
- is useful if you want more control over how to convert `input_ids` indices into associated vectors than the
567
- model's internal embedding lookup matrix.
568
- use_cache (`bool`, *optional*):
569
- If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding (see
570
- `past_key_values`).
571
- output_attentions (`bool`, *optional*):
572
- Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned
573
- tensors for more detail.
574
- output_hidden_states (`bool`, *optional*):
575
- Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for
576
- more detail.
577
- return_dict (`bool`, *optional*):
578
- Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple.
579
- """
580
-
581
-
582
- @add_start_docstrings(
583
- "The bare LLaMA Model outputting raw hidden-states without any specific head on top.",
584
- LLAMA_START_DOCSTRING,
585
- )
586
- class LlamaModel(LlamaPreTrainedModel):
587
- """
588
- Transformer decoder consisting of *config.num_hidden_layers* layers. Each layer is a [`LlamaDecoderLayer`]
589
-
590
- Args:
591
- config: LlamaConfig
592
- """
593
-
594
- def __init__(self, config: LlamaConfig):
595
- super().__init__(config)
596
- self.padding_idx = config.pad_token_id
597
- self.vocab_size = config.vocab_size
598
-
599
- self.embed_tokens = nn.Embedding(config.vocab_size, config.hidden_size, self.padding_idx)
600
- self.layers = nn.ModuleList([LlamaDecoderLayer(config) for _ in range(config.num_hidden_layers)])
601
- self.norm = LlamaRMSNorm(config.hidden_size, eps=config.rms_norm_eps)
602
-
603
- self.gradient_checkpointing = False
604
- # Initialize weights and apply final processing
605
- self.post_init()
606
-
607
- def get_input_embeddings(self):
608
- return self.embed_tokens
609
-
610
- def set_input_embeddings(self, value):
611
- self.embed_tokens = value
612
-
613
- @add_start_docstrings_to_model_forward(LLAMA_INPUTS_DOCSTRING)
614
- def forward(
615
- self,
616
- input_ids: torch.LongTensor = None,
617
- attention_mask: Optional[torch.Tensor] = None,
618
- position_ids: Optional[torch.LongTensor] = None,
619
- past_key_values: Optional[List[torch.FloatTensor]] = None,
620
- inputs_embeds: Optional[torch.FloatTensor] = None,
621
- use_cache: Optional[bool] = None,
622
- output_attentions: Optional[bool] = None,
623
- output_hidden_states: Optional[bool] = None,
624
- return_dict: Optional[bool] = None,
625
- is_padded_inputs: Optional[bool] = False,
626
- ) -> Union[Tuple, BaseModelOutputWithPast]:
627
- output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
628
- output_hidden_states = (
629
- output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
630
- )
631
- use_cache = use_cache if use_cache is not None else self.config.use_cache
632
-
633
- return_dict = return_dict if return_dict is not None else self.config.use_return_dict
634
-
635
- # retrieve input_ids and inputs_embeds
636
- if input_ids is not None and inputs_embeds is not None:
637
- raise ValueError("You cannot specify both decoder_input_ids and decoder_inputs_embeds at the same time")
638
- elif input_ids is not None:
639
- batch_size, seq_length = input_ids.shape
640
- elif inputs_embeds is not None:
641
- batch_size, seq_length, _ = inputs_embeds.shape
642
- else:
643
- raise ValueError("You have to specify either decoder_input_ids or decoder_inputs_embeds")
644
-
645
- seq_length_with_past = seq_length
646
- past_key_values_length = 0
647
-
648
- if past_key_values is not None:
649
- past_key_values_length = past_key_values[0][0].shape[2]
650
- seq_length_with_past = seq_length_with_past + past_key_values_length
651
-
652
- position_ids = None
653
-
654
- if inputs_embeds is None:
655
- inputs_embeds = self.embed_tokens(input_ids)
656
-
657
- hidden_states = inputs_embeds
658
-
659
- if self.gradient_checkpointing and self.training:
660
- if use_cache:
661
- logger.warning_once(
662
- "`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..."
663
- )
664
- use_cache = False
665
-
666
- # decoder layers
667
- all_hidden_states = () if output_hidden_states else None
668
- all_self_attns = () if output_attentions else None
669
- next_decoder_cache = () if use_cache else None
670
-
671
- for idx, decoder_layer in enumerate(self.layers):
672
- if output_hidden_states:
673
- all_hidden_states += (hidden_states,)
674
-
675
- past_key_value = past_key_values[idx] if past_key_values is not None else None
676
-
677
- if self.gradient_checkpointing and self.training:
678
-
679
- def create_custom_forward(module):
680
- def custom_forward(*inputs):
681
- # None for past_key_value
682
- return module(*inputs, output_attentions, None)
683
-
684
- return custom_forward
685
-
686
- layer_outputs = torch.utils.checkpoint.checkpoint(
687
- create_custom_forward(decoder_layer),
688
- hidden_states,
689
- attention_mask,
690
- position_ids,
691
- None,
692
- is_padded_inputs
693
- )
694
- else:
695
- layer_outputs = decoder_layer(
696
- hidden_states,
697
- attention_mask=attention_mask,
698
- position_ids=position_ids,
699
- past_key_value=past_key_value,
700
- output_attentions=output_attentions,
701
- use_cache=use_cache,
702
- is_padded_inputs=is_padded_inputs,
703
- )
704
-
705
- hidden_states = layer_outputs[0]
706
-
707
- if use_cache:
708
- next_decoder_cache += (layer_outputs[2 if output_attentions else 1],)
709
-
710
- if output_attentions:
711
- all_self_attns += (layer_outputs[1],)
712
-
713
- hidden_states = self.norm(hidden_states)
714
-
715
- # add hidden states from the last decoder layer
716
- if output_hidden_states:
717
- all_hidden_states += (hidden_states,)
718
-
719
- next_cache = next_decoder_cache if use_cache else None
720
- if not return_dict:
721
- return tuple(v for v in [hidden_states, next_cache, all_hidden_states, all_self_attns] if v is not None)
722
- return BaseModelOutputWithPast(
723
- last_hidden_state=hidden_states,
724
- past_key_values=next_cache,
725
- hidden_states=all_hidden_states,
726
- attentions=all_self_attns,
727
- )
728
-
729
-
730
- class LlamaForCausalLM(LlamaPreTrainedModel):
731
- _tied_weights_keys = ["lm_head.weight"]
732
-
733
- def __init__(self, config):
734
- super().__init__(config)
735
- self.model = LlamaModel(config)
736
- self.vocab_size = config.vocab_size
737
- self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False)
738
-
739
- # Initialize weights and apply final processing
740
- self.post_init()
741
-
742
- def get_input_embeddings(self):
743
- return self.model.embed_tokens
744
-
745
- def set_input_embeddings(self, value):
746
- self.model.embed_tokens = value
747
-
748
- def get_output_embeddings(self):
749
- return self.lm_head
750
-
751
- def set_output_embeddings(self, new_embeddings):
752
- self.lm_head = new_embeddings
753
-
754
- def set_decoder(self, decoder):
755
- self.model = decoder
756
-
757
- def get_decoder(self):
758
- return self.model
759
-
760
- @add_start_docstrings_to_model_forward(LLAMA_INPUTS_DOCSTRING)
761
- @replace_return_docstrings(output_type=CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC)
762
- def forward(
763
- self,
764
- input_ids: torch.LongTensor = None,
765
- attention_mask: Optional[torch.Tensor] = None,
766
- position_ids: Optional[torch.LongTensor] = None,
767
- past_key_values: Optional[List[torch.FloatTensor]] = None,
768
- inputs_embeds: Optional[torch.FloatTensor] = None,
769
- labels: Optional[torch.LongTensor] = None,
770
- use_cache: Optional[bool] = None,
771
- output_attentions: Optional[bool] = None,
772
- output_hidden_states: Optional[bool] = None,
773
- return_dict: Optional[bool] = None,
774
- is_padded_inputs: Optional[bool] = None,
775
- ) -> Union[Tuple, CausalLMOutputWithPast]:
776
- r"""
777
- Args:
778
- labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
779
- Labels for computing the masked language modeling loss. Indices should either be in `[0, ...,
780
- config.vocab_size]` or -100 (see `input_ids` docstring). Tokens with indices set to `-100` are ignored
781
- (masked), the loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`.
782
-
783
- Returns:
784
-
785
- Example:
786
-
787
- ```python
788
- >>> from transformers import AutoTokenizer, LlamaForCausalLM
789
-
790
- >>> model = LlamaForCausalLM.from_pretrained(PATH_TO_CONVERTED_WEIGHTS)
791
- >>> tokenizer = AutoTokenizer.from_pretrained(PATH_TO_CONVERTED_TOKENIZER)
792
-
793
- >>> prompt = "Hey, are you conscious? Can you talk to me?"
794
- >>> inputs = tokenizer(prompt, return_tensors="pt")
795
-
796
- >>> # Generate
797
- >>> generate_ids = model.generate(inputs.input_ids, max_length=30)
798
- >>> tokenizer.batch_decode(generate_ids, skip_special_tokens=True, clean_up_tokenization_spaces=False)[0]
799
- "Hey, are you conscious? Can you talk to me?\nI'm not conscious, but I can talk to you."
800
- ```"""
801
-
802
- output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
803
- output_hidden_states = (
804
- output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
805
- )
806
- return_dict = return_dict if return_dict is not None else self.config.use_return_dict
807
-
808
- is_padded_inputs = ((attention_mask is not None) and (not attention_mask.all().item()))
809
-
810
- # decoder outputs consists of (dec_features, layer_state, dec_hidden, dec_attn)
811
- outputs = self.model(
812
- input_ids=input_ids,
813
- attention_mask=attention_mask,
814
- position_ids=position_ids,
815
- past_key_values=past_key_values,
816
- inputs_embeds=inputs_embeds,
817
- use_cache=use_cache,
818
- output_attentions=output_attentions,
819
- output_hidden_states=output_hidden_states,
820
- return_dict=return_dict,
821
- is_padded_inputs=is_padded_inputs,
822
- )
823
-
824
- hidden_states = outputs[0]
825
- if self.config.pretraining_tp > 1:
826
- lm_head_slices = self.lm_head.weight.split(self.vocab_size // self.config.pretraining_tp, dim=0)
827
- logits = [F.linear(hidden_states, lm_head_slices[i]) for i in range(self.config.pretraining_tp)]
828
- logits = torch.cat(logits, dim=-1)
829
- else:
830
- logits = self.lm_head(hidden_states)
831
- logits = logits.float()
832
-
833
- loss = None
834
- if labels is not None:
835
- # Shift so that tokens < n predict n
836
- shift_logits = logits[..., :-1, :].contiguous()
837
- shift_labels = labels[..., 1:].contiguous()
838
- # Flatten the tokens
839
- loss_fct = CrossEntropyLoss()
840
- shift_logits = shift_logits.view(-1, self.config.vocab_size)
841
- shift_labels = shift_labels.view(-1)
842
- # Enable model parallelism
843
- shift_labels = shift_labels.to(shift_logits.device)
844
- loss = loss_fct(shift_logits, shift_labels)
845
-
846
- if not return_dict:
847
- output = (logits,) + outputs[1:]
848
- return (loss,) + output if loss is not None else output
849
-
850
- return CausalLMOutputWithPast(
851
- loss=loss,
852
- logits=logits,
853
- past_key_values=outputs.past_key_values,
854
- hidden_states=outputs.hidden_states,
855
- attentions=outputs.attentions,
856
- )
857
-
858
- def prepare_inputs_for_generation(
859
- self, input_ids, past_key_values=None, attention_mask=None, inputs_embeds=None, **kwargs
860
- ):
861
- if past_key_values:
862
- input_ids = input_ids[:, -1:]
863
-
864
- position_ids = kwargs.get("position_ids", None)
865
-
866
- # if `inputs_embeds` are passed, we only want to use them in the 1st generation step
867
- if inputs_embeds is not None and past_key_values is None:
868
- model_inputs = {"inputs_embeds": inputs_embeds}
869
- else:
870
- model_inputs = {"input_ids": input_ids}
871
-
872
- model_inputs.update(
873
- {
874
- "position_ids": position_ids,
875
- "past_key_values": past_key_values,
876
- "use_cache": kwargs.get("use_cache"),
877
- "attention_mask": attention_mask,
878
- "is_padded_inputs": ((attention_mask is not None) and (not attention_mask.all().item()))
879
- }
880
- )
881
- return model_inputs
882
-
883
- @staticmethod
884
- def _reorder_cache(past_key_values, beam_idx):
885
- reordered_past = ()
886
- for layer_past in past_key_values:
887
- reordered_past += (
888
- tuple(past_state.index_select(0, beam_idx.to(past_state.device)) for past_state in layer_past),
889
- )
890
- return reordered_past
891
-
892
-
893
- @add_start_docstrings(
894
- """
895
- The LLaMa Model transformer with a sequence classification head on top (linear layer).
896
-
897
- [`LlamaForSequenceClassification`] uses the last token in order to do the classification, as other causal models
898
- (e.g. GPT-2) do.
899
-
900
- Since it does classification on the last token, it requires to know the position of the last token. If a
901
- `pad_token_id` is defined in the configuration, it finds the last token that is not a padding token in each row. If
902
- no `pad_token_id` is defined, it simply takes the last value in each row of the batch. Since it cannot guess the
903
- padding tokens when `inputs_embeds` are passed instead of `input_ids`, it does the same (take the last value in
904
- each row of the batch).
905
- """,
906
- LLAMA_START_DOCSTRING,
907
- )
908
- class LlamaForSequenceClassification(LlamaPreTrainedModel):
909
- def __init__(self, config):
910
- super().__init__(config)
911
- self.num_labels = config.num_labels
912
- self.model = LlamaModel(config)
913
- self.score = nn.Linear(config.hidden_size, self.num_labels, bias=False)
914
-
915
- # Initialize weights and apply final processing
916
- self.post_init()
917
-
918
- def get_input_embeddings(self):
919
- return self.model.embed_tokens
920
-
921
- def set_input_embeddings(self, value):
922
- self.model.embed_tokens = value
923
-
924
- @add_start_docstrings_to_model_forward(LLAMA_INPUTS_DOCSTRING)
925
- def forward(
926
- self,
927
- input_ids: torch.LongTensor = None,
928
- attention_mask: Optional[torch.Tensor] = None,
929
- position_ids: Optional[torch.LongTensor] = None,
930
- past_key_values: Optional[List[torch.FloatTensor]] = None,
931
- inputs_embeds: Optional[torch.FloatTensor] = None,
932
- labels: Optional[torch.LongTensor] = None,
933
- use_cache: Optional[bool] = None,
934
- output_attentions: Optional[bool] = None,
935
- output_hidden_states: Optional[bool] = None,
936
- return_dict: Optional[bool] = None,
937
- ) -> Union[Tuple, SequenceClassifierOutputWithPast]:
938
- r"""
939
- labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
940
- Labels for computing the sequence classification/regression loss. Indices should be in `[0, ...,
941
- config.num_labels - 1]`. If `config.num_labels == 1` a regression loss is computed (Mean-Square loss), If
942
- `config.num_labels > 1` a classification loss is computed (Cross-Entropy).
943
- """
944
- return_dict = return_dict if return_dict is not None else self.config.use_return_dict
945
-
946
- transformer_outputs = self.model(
947
- input_ids,
948
- attention_mask=attention_mask,
949
- position_ids=position_ids,
950
- past_key_values=past_key_values,
951
- inputs_embeds=inputs_embeds,
952
- use_cache=use_cache,
953
- output_attentions=output_attentions,
954
- output_hidden_states=output_hidden_states,
955
- return_dict=return_dict,
956
- )
957
- hidden_states = transformer_outputs[0]
958
- logits = self.score(hidden_states)
959
-
960
- if input_ids is not None:
961
- batch_size = input_ids.shape[0]
962
- else:
963
- batch_size = inputs_embeds.shape[0]
964
-
965
- if self.config.pad_token_id is None and batch_size != 1:
966
- raise ValueError("Cannot handle batch sizes > 1 if no padding token is defined.")
967
- if self.config.pad_token_id is None:
968
- sequence_lengths = -1
969
- else:
970
- if input_ids is not None:
971
- sequence_lengths = (torch.ne(input_ids, self.config.pad_token_id).sum(-1) - 1).to(logits.device)
972
- else:
973
- sequence_lengths = -1
974
-
975
- pooled_logits = logits[torch.arange(batch_size, device=logits.device), sequence_lengths]
976
-
977
- loss = None
978
- if labels is not None:
979
- labels = labels.to(logits.device)
980
- if self.config.problem_type is None:
981
- if self.num_labels == 1:
982
- self.config.problem_type = "regression"
983
- elif self.num_labels > 1 and (labels.dtype == torch.long or labels.dtype == torch.int):
984
- self.config.problem_type = "single_label_classification"
985
- else:
986
- self.config.problem_type = "multi_label_classification"
987
-
988
- if self.config.problem_type == "regression":
989
- loss_fct = MSELoss()
990
- if self.num_labels == 1:
991
- loss = loss_fct(pooled_logits.squeeze(), labels.squeeze())
992
- else:
993
- loss = loss_fct(pooled_logits, labels)
994
- elif self.config.problem_type == "single_label_classification":
995
- loss_fct = CrossEntropyLoss()
996
- loss = loss_fct(pooled_logits.view(-1, self.num_labels), labels.view(-1))
997
- elif self.config.problem_type == "multi_label_classification":
998
- loss_fct = BCEWithLogitsLoss()
999
- loss = loss_fct(pooled_logits, labels)
1000
- if not return_dict:
1001
- output = (pooled_logits,) + transformer_outputs[1:]
1002
- return ((loss,) + output) if loss is not None else output
1003
-
1004
- return SequenceClassifierOutputWithPast(
1005
- loss=loss,
1006
- logits=pooled_logits,
1007
- past_key_values=transformer_outputs.past_key_values,
1008
- hidden_states=transformer_outputs.hidden_states,
1009
- attentions=transformer_outputs.attentions,
1010
- )