jiang-base-30000steps / modeling_gpt_jiang.py
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# coding=utf-8
# Copyright 2023 EleutherAI The HuggingFace Inc. team. and JIANG.ai All rights reserved.
#
# 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.
""" PyTorch GPTJiang model."""
from typing import Optional, Tuple, Union
import torch
import torch.utils.checkpoint
from torch import nn
from torch.nn import CrossEntropyLoss
import torch.nn.functional as F
from transformers.activations import ACT2FN
from transformers.file_utils import (
add_code_sample_docstrings,
add_start_docstrings,
add_start_docstrings_to_model_forward,
replace_return_docstrings,
)
from transformers.modeling_outputs import BaseModelOutputWithPast, CausalLMOutputWithPast
from transformers.modeling_utils import PreTrainedModel
from transformers.utils import logging
from .configuration_gpt_jiang import GPTJiangConfig
logger = logging.get_logger(__name__)
_CONFIG_FOR_DOC = "GPTJiangConfig"
GPT_JIANG_PRETRAINED_MODEL_ARCHIVE_LIST = []
class RMSNorm(torch.nn.Module):
def __init__(self, dim: int, eps: float=1e-5):
super().__init__()
self.eps = eps
self.weight = nn.Parameter(torch.ones(dim))
def _norm(self, x):
return x * torch.rsqrt(x.pow(2).mean(-1, keepdim=True) + self.eps)
def forward(self, x):
output = self._norm(x.float()).type_as(x)
return output * self.weight
class GPTJiangPreTrainedModel(PreTrainedModel):
"""
An abstract class to handle weights initialization and a simple interface for downloading and loading pretrained
models.
"""
config_class = GPTJiangConfig
base_model_prefix = "gpt_jiang"
supports_gradient_checkpointing = True
_no_split_modules = ["GPTJiangLayer"]
def _init_weights(self, module):
"""Initialize the weights"""
if isinstance(module, GatedLinear):
module.weight.data.normal_(mean=0.0, std=self.config.initializer_range)
if module.bias is not None:
module.bias.data.fill_(1.0)
elif isinstance(module, nn.Linear):
module.weight.data.normal_(mean=0.0, std=self.config.initializer_range)
if module.bias is not None:
module.bias.data.zero_()
elif isinstance(module, nn.Embedding):
module.weight.data.normal_(mean=0.0, std=self.config.initializer_range)
if module.padding_idx is not None:
module.weight.data[module.padding_idx].zero_()
elif isinstance(module, RMSNorm):
# module.bias.data.zero_()
module.weight.data.fill_(1.0)
def _set_gradient_checkpointing(self, module, value=False):
if isinstance(module, GPTJiangModel):
module.gradient_checkpointing = value
class GPTJiangAttention(nn.Module):
def __init__(self, config):
super().__init__()
self.max_position_embeddings = config.max_position_embeddings
self.num_attention_heads = config.num_attention_heads
self.hidden_size = config.hidden_size
self.head_size = self.hidden_size // self.num_attention_heads
self.rotary_ndims = int(self.head_size * config.rotary_pct)
self.rotary_emb = RotaryEmbedding(
self.rotary_ndims,
config.max_position_embeddings,
base=config.rotary_emb_base
)
self.query_key_value = nn.Linear(config.hidden_size, 3 * config.hidden_size)
self.dense = nn.Linear(config.hidden_size, config.hidden_size)
self.causal_mask_cached = None
def causal_mask(self, x, seq_len):
if self.causal_mask_cached is None or seq_len > self.causal_mask_cached.shape[2]:
cache_size = max(self.max_position_embeddings, seq_len)
self.causal_mask_cached = torch.ones(
cache_size,
cache_size,
dtype=torch.bool
).tril().view(1, 1, cache_size, cache_size)
return self.causal_mask_cached[:, :, :seq_len, :seq_len].to(x.device)
def forward(
self,
hidden_states,
attention_mask,
head_mask=None,
layer_past=None,
use_cache=False,
output_attentions=False
):
has_layer_past = layer_past is not None
# Compute QKV
# Attention heads [batch, seq_len, hidden_size]
# --> [batch, seq_len, (np * 3 * head_size)]
qkv = self.query_key_value(hidden_states)
# [batch, seq_len, (num_heads * 3 * head_size)]
# --> [batch, seq_len, num_heads, 3 * head_size]
new_qkv_shape = qkv.size()[:-1] + (self.num_attention_heads, 3 * self.head_size)
qkv = qkv.view(*new_qkv_shape)
# [batch, seq_len, num_attention_heads, 3 * head_size] --> 3 [batch, num_attention_heads, seq_len, head_size]
query = qkv[..., : self.head_size].permute(0, 2, 1, 3)
key = qkv[..., self.head_size : 2 * self.head_size].permute(0, 2, 1, 3)
value = qkv[..., 2 * self.head_size :].permute(0, 2, 1, 3)
# Compute rotary embeddings on rotary_ndims
# query_rot = query[..., : self.rotary_ndims]
# query_pass = query[..., self.rotary_ndims :]
# key_rot = key[..., : self.rotary_ndims]
# key_pass = key[..., self.rotary_ndims :]
# Compute token offset for rotary embeddings (when decoding)
seq_len = key.shape[-2]
offset = 0
if has_layer_past:
offset = layer_past[0].shape[-2]
seq_len += offset
cos, sin = self.rotary_emb(value, seq_len=seq_len)
query, key = apply_rotary_pos_emb(query, key, cos, sin, offset=offset)
# query, key = apply_rotary_pos_emb(query_rot, key_rot, cos, sin, offset=offset)
# query = torch.cat((query, query_pass), dim=-1)
# key = torch.cat((key, key_pass), dim=-1)
# Cache QKV values
if has_layer_past:
past_key = layer_past[0]
past_value = layer_past[1]
key = torch.cat((past_key, key), dim=-2)
value = torch.cat((past_value, value), dim=-2)
present = (key, value,) if use_cache else None
query = query.type_as(hidden_states)
key = key.type_as(hidden_states)
value = value.type_as(hidden_states)
if output_attentions:
# Use custom attention method to get attn_weights
attn_output, attn_weights = self._attn(
query, key, value,
attention_mask=attention_mask,
head_mask=head_mask
)
else:
if layer_past is not None and attention_mask is None:
# Must calculate attention_mask, or scaled_dot_product_attention will wrong
batch_size = query.size(0)
attention_mask = torch.ones(batch_size, seq_len, dtype=torch.bool)[:, None, None, :]
if attention_mask is not None:
attn_mask = attention_mask.transpose(2, 3) * attention_mask
query_length = query.size(-2)
key_length = key.size(-2)
if query_length > 1:
causal_mask = self.causal_mask(query, seq_len)
causal_mask = causal_mask[:, :, -query_length:, :]
attn_mask = (attn_mask[:, :, -query_length:, :] * causal_mask).to(torch.bool)
else:
attn_mask = attn_mask[:, :, -query_length:, :].to(torch.bool)
attn_output = F.scaled_dot_product_attention(
query,
key,
value,
attn_mask=attn_mask,
is_causal=False
)
else:
attn_output = F.scaled_dot_product_attention(
query,
key,
value,
attn_mask=None,
is_causal=True
)
attn_weights = None
# Reshape outputs
# attn_output == [bs, num_attention_heads, seq_len, attn_head_size]
attn_output = self._merge_heads(attn_output, self.num_attention_heads, self.head_size)
# tensor [bs, seq_len, num_attention_heads * attn_head_size]
attn_output = self.dense(attn_output)
outputs = (attn_output, present)
if output_attentions:
outputs += (attn_weights,)
return outputs
@classmethod
def _calculate_attn_output_loss(self, attn_output):
bs, num_attention_heads, seq_len, attn_head_size = attn_output.size()
attn_output_out = attn_output.view(bs, num_attention_heads, -1)
attn_output_out_norm = attn_output_out / torch.max(
attn_output_out.norm(dim=2, keepdim=True),
1e-8 * torch.ones_like(attn_output_out)
)
sim = torch.bmm(attn_output_out_norm, attn_output_out_norm.permute(0, 2, 1))
attn_output_loss = sim.sum() / sim.numel()
return attn_output_loss
@classmethod
def _split_heads(cls, tensor, num_attention_heads, attn_head_size):
"""
Splits hidden dim into attn_head_size and num_attention_heads
"""
# tensor: [bs, seq_len, hidden_size]
new_shape = tensor.size()[:-1] + (num_attention_heads, attn_head_size)
# -> [bs, seq_len, num_attention_heads, attn_head_size]
tensor = tensor.view(new_shape)
# -> [bs, num_attention_heads, seq_len, attn_head_size]
tensor = tensor.permute(0, 2, 1, 3)
return tensor
@classmethod
def _merge_heads(cls, tensor, num_attention_heads, attn_head_size):
"""
Merges attn_head_size dim and num_attn_heads dim into hidden dim
"""
# tensor [bs, num_attention_heads, seq_len, attn_head_size]
tensor = tensor.permute(0, 2, 1, 3).contiguous()
# -> [bs, seq_len, num_attention_heads, attn_head_size]
tensor = tensor.view(tensor.size(0), tensor.size(1), num_attention_heads * attn_head_size)
# -> [bs, seq_len, hidden_size]
return tensor
def create_upper_triangular_matrix(self, q, k):
size = max(q, k)
# 创建一个单位矩阵
identity = torch.eye(size)
# 创建一个矩阵,其中每个元素都是它的行索引
row_indices = torch.arange(size).view(-1, 1).expand(size, size)
# 创建一个矩阵,其中每个元素都是它的列索引
col_indices = torch.arange(size).view(1, -1).expand(size, size)
# 比较行和列索引,如果行索引小于列索引,则0,否则1
upper_triangular_matrix = torch.where(row_indices < col_indices, 0, 1)
return upper_triangular_matrix[-q:, -k:].to(torch.bool)
def _attn(self, query, key, value, attention_mask=None, head_mask=None):
# q, k, v: [bs, num_attention_heads, seq_len, attn_head_size]
# compute causal mask from causal mask buffer
batch_size, num_attention_heads, query_length, attn_head_size = query.size()
key_length = key.size(-2)
# 避免使用tril
# causal_mask = torch.ones(
# query_length, key_length,
# dtype=torch.bool,
# device=query.device
# ).tril(
# diagonal=key_length - query_length
# ).view(1, 1, query_length, key_length)
causal_mask = self.create_upper_triangular_matrix(
query_length, key_length
).view(1, 1, query_length, key_length).to(query.device)
query = query.view(batch_size * num_attention_heads, query_length, attn_head_size)
key = key.view(batch_size * num_attention_heads, key_length, attn_head_size)
attn_scores = torch.zeros(
batch_size * num_attention_heads,
query_length,
key_length,
dtype=query.dtype,
device=key.device,
)
norm_factor = self.head_size ** 0.5
attn_scores = torch.baddbmm(
attn_scores,
query,
key.transpose(1, 2),
beta=1.0,
alpha=(torch.tensor(1.0, dtype=query.dtype, device=query.device) / norm_factor),
)
attn_scores = attn_scores.view(batch_size, num_attention_heads, query_length, key_length)
mask_value = torch.finfo(attn_scores.dtype).min
# Need to be a tensor, otherwise we get error: `RuntimeError: expected scalar type float but found double`.
# Need to be on the same device, otherwise `RuntimeError: ..., x and y to be on the same device`
mask_value = torch.tensor(mask_value, dtype=attn_scores.dtype).to(attn_scores.device)
attn_scores = torch.where(causal_mask, attn_scores, mask_value)
if attention_mask is not None:
# Apply the attention mask
attn_scores = attn_scores + attention_mask
attn_weights = nn.functional.softmax(attn_scores.float(), dim=-1).type_as(value)
# Mask heads if we want to
if head_mask is not None:
attn_weights = attn_weights * head_mask
attn_output = torch.matmul(attn_weights, value)
return attn_output, attn_weights
class RotaryEmbedding(torch.nn.Module):
def __init__(self, dim, max_position_embeddings, base=10000, device=None):
super().__init__()
inv_freq = 1.0 / (base ** (torch.arange(0, dim, 2).float().to(device) / dim))
self.register_buffer("inv_freq", inv_freq)
# Build here to make `torch.jit.trace` work.
self.max_seq_len_cached = max_position_embeddings
t = torch.arange(self.max_seq_len_cached, device=self.inv_freq.device, dtype=self.inv_freq.dtype)
freqs = torch.einsum("i,j->ij", t, self.inv_freq)
# Different from paper, but it uses a different permutation in order to obtain the same calculation
emb = torch.cat((freqs, freqs), dim=-1)
self.cos_cached = emb.cos()[None, None, :, :]
self.sin_cached = emb.sin()[None, None, :, :]
def forward(self, x, seq_len=None):
# x: [bs, num_attention_heads, seq_len, head_size]
# This `if` block is unlikely to be run after we build sin/cos in `__init__`. Keep the logic here just in case.
if seq_len > self.max_seq_len_cached:
self.max_seq_len_cached = seq_len
t = torch.arange(self.max_seq_len_cached, device=x.device, dtype=self.inv_freq.dtype)
freqs = torch.einsum("i,j->ij", t, self.inv_freq)
# Different from paper, but it uses a different permutation in order to obtain the same calculation
emb = torch.cat((freqs, freqs), dim=-1).to(x.device)
self.cos_cached = emb.cos()[None, None, :, :]
self.sin_cached = emb.sin()[None, None, :, :]
return self.cos_cached[:seq_len, ...].to(x.device), self.sin_cached[:seq_len, ...].to(x.device)
def rotate_half(x):
"""Rotates half the hidden dims of the input."""
x1 = x[..., : x.shape[-1] // 2]
x2 = x[..., x.shape[-1] // 2 :]
return torch.cat((-x2, x1), dim=-1)
def apply_rotary_pos_emb(q, k, cos, sin, offset: int = 0):
cos = cos[..., offset : q.shape[-2] + offset, :]
sin = sin[..., offset : q.shape[-2] + offset, :]
q_embed = (q * cos) + (rotate_half(q) * sin)
k_embed = (k * cos) + (rotate_half(k) * sin)
return q_embed, k_embed
class GatedLinear(nn.Linear):
pass
class GPTJiangMLP(nn.Module):
def __init__(self, config):
super().__init__()
self.dense_h_to_4h = nn.Linear(config.hidden_size, config.intermediate_size, bias=config.mlp_bias)
self.dense_4h_to_h = nn.Linear(config.intermediate_size, config.hidden_size, bias=config.mlp_bias)
self.gated = config.gated
if config.gated:
self.dense_h_to_4h_gate = GatedLinear(config.hidden_size, config.intermediate_size, bias=config.mlp_bias)
self.act = ACT2FN[config.hidden_act]
def forward(self, hidden_states):
if self.gated:
# pseudocode:
# g is activation function, W and V are weights, * is element-wised product
# x = g(Wx) * Vx
hidden_states = self.act(self.dense_h_to_4h(hidden_states)) * self.dense_h_to_4h_gate(hidden_states)
else:
# pseudocode:
# x = g(Wx)
hidden_states = self.act(self.dense_h_to_4h(hidden_states))
hidden_states = self.dense_4h_to_h(hidden_states)
return hidden_states
class GPTJiangLayer(nn.Module):
def __init__(self, config):
super().__init__()
self.use_parallel_residual = config.use_parallel_residual
self.input_layernorm = RMSNorm(config.hidden_size, eps=config.layer_norm_eps)
self.post_attention_layernorm = RMSNorm(config.hidden_size, eps=config.layer_norm_eps)
self.attention = GPTJiangAttention(config)
self.mlp = GPTJiangMLP(config)
def forward(
self,
hidden_states,
attention_mask=None,
head_mask=None,
use_cache=False,
layer_past=None,
output_attentions=False,
):
attention_layer_outputs = self.attention(
self.input_layernorm(hidden_states),
attention_mask=attention_mask,
layer_past=layer_past,
head_mask=head_mask,
use_cache=use_cache,
output_attentions=output_attentions,
)
attn_output = attention_layer_outputs[0] # output_attn: attn_output, present, (attn_weights), (attentions_output_loss)
outputs = attention_layer_outputs[1:]
# Default True in multiple models, faster
if self.use_parallel_residual:
# pseudocode:
# x = x + attn(ln1(x)) + mlp(ln2(x))
mlp_output = self.mlp(self.post_attention_layernorm(hidden_states))
hidden_states = mlp_output + attn_output + hidden_states
else:
# pseudocode:
# x = x + attn(ln1(x))
# x = x + mlp(ln2(x))
attn_output = attn_output + hidden_states
mlp_output = self.mlp(self.post_attention_layernorm(attn_output))
hidden_states = mlp_output + attn_output
if use_cache:
outputs = (hidden_states,) + outputs # hidden_states, present, (attn_weights), (attentions_output_loss)
else:
outputs = (hidden_states,) + outputs[1:] # hidden_states, (attn_weights), (attentions_output_loss)
return outputs
GPT_JIANG_START_DOCSTRING = r"""
This model is a PyTorch [torch.nn.Module](https://pytorch.org/docs/stable/nn.html#torch.nn.Module) sub-class. Use
it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage and
behavior.
Parameters:
config ([`~GPTJiangConfig`]): Model configuration class with all the parameters of the model.
Initializing with a config file does not load the weights associated with the model, only the
configuration. Check out the [`~PreTrainedModel.from_pretrained`] method to load the model weights.
"""
GPT_JIANG_INPUTS_DOCSTRING = r"""
Args:
input_ids (`torch.LongTensor` of shape `({0})`):
Indices of input sequence tokens in the vocabulary.
Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
[`PreTrainedTokenizer.__call__`] for details.
[What are input IDs?](../glossary#input-ids)
attention_mask (`torch.FloatTensor` of shape `({0})`, *optional*):
Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`:
- 1 for tokens that are **not masked**,
- 0 for tokens that are **masked**.
[What are attention masks?](../glossary#attention-mask)
head_mask (`torch.FloatTensor` of shape `(num_heads,)` or `(num_layers, num_heads)`, *optional*):
Mask to nullify selected heads of the self-attention modules. Mask values selected in `[0, 1]`:
- 1 indicates the head is **not masked**,
- 0 indicates the head is **masked**.
inputs_embeds (`torch.FloatTensor` of shape `({0}, hidden_size)`, *optional*):
Optionally, instead of passing `input_ids` you can choose to directly pass an embedded representation. This
is useful if you want more control over how to convert *input_ids* indices into associated vectors than the
model's internal embedding lookup matrix.
output_attentions (`bool`, *optional*):
Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned
tensors for more detail.
output_hidden_states (`bool`, *optional*):
Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for
more detail.
return_dict (`bool`, *optional*):
Whether or not to return a [`~file_utils.ModelOutput`] instead of a plain tuple.
"""
@add_start_docstrings(
"The bare GPTJiang Model transformer outputting raw hidden-states without any specific head on top.",
GPT_JIANG_START_DOCSTRING,
)
class GPTJiangModel(GPTJiangPreTrainedModel):
def __init__(self, config):
super().__init__(config)
self.config = config
self.embed_in = nn.Embedding(config.vocab_size, config.hidden_size)
self.layers = nn.ModuleList([GPTJiangLayer(config) for _ in range(config.num_hidden_layers)])
self.final_layer_norm = RMSNorm(config.hidden_size, eps=config.layer_norm_eps)
self.gradient_checkpointing = False
# Initialize weights and apply final processing
self.post_init()
def get_input_embeddings(self):
return self.embed_in
def set_input_embeddings(self, value):
self.embed_in = value
@add_start_docstrings_to_model_forward(GPT_JIANG_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
@add_code_sample_docstrings(
output_type=BaseModelOutputWithPast,
config_class=_CONFIG_FOR_DOC,
)
def forward(
self,
input_ids: Optional[torch.LongTensor] = None,
attention_mask: Optional[torch.FloatTensor] = None,
head_mask: Optional[torch.FloatTensor] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
past_key_values: Optional[Tuple[Tuple[torch.FloatTensor]]] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[Tuple, BaseModelOutputWithPast]:
r"""
past_key_values (`tuple(tuple(torch.FloatTensor))` of length `config.n_layers` with each tuple having 4 tensors of shape `(batch_size, num_heads, sequence_length - 1, embed_size_per_head)`):
Contains precomputed key and value hidden states of the attention blocks. Can be used to speed up decoding.
If `past_key_values` are used, the user can optionally input only the last `decoder_input_ids` (those that
don't have their past key value states given to this model) of shape `(batch_size, 1)` instead of all
`decoder_input_ids` of shape `(batch_size, sequence_length)`.
use_cache (`bool`, *optional*):
If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding (see `past_key_values`).
"""
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
output_hidden_states = (
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
)
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
use_cache = use_cache if use_cache is not None else self.config.use_cache
if input_ids is not None and inputs_embeds is not None:
raise ValueError("You cannot specify both input_ids and inputs_embeds at the same time")
elif input_ids is not None:
input_shape = input_ids.size()
elif inputs_embeds is not None:
input_shape = inputs_embeds.size()[:-1]
else:
raise ValueError("You have to specify either input_ids or inputs_embeds")
batch_size, seq_length = input_shape
if past_key_values is None:
past_key_values = tuple([None] * self.config.num_hidden_layers)
# Attention mask.
if attention_mask is not None:
assert batch_size > 0, "batch_size has to be defined and > 0"
attention_mask = attention_mask.view(batch_size, -1)
# We create a 3D attention mask from a 2D tensor mask.
# Sizes are [batch_size, 1, 1, to_seq_length]
# So we can broadcast to [batch_size, num_heads, from_seq_length, to_seq_length]
# this attention mask is more simple than the triangular masking of causal attention
# used in OpenAI GPT, we just need to prepare the broadcast dimension here.
attention_mask = attention_mask[:, None, None, :]
# Since attention_mask is 1.0 for positions we want to attend and 0.0 for
# masked positions, this operation will create a tensor which is 0.0 for
# positions we want to attend and the dtype's smallest value for masked positions.
# Since we are adding it to the raw scores before the softmax, this is
# effectively the same as removing these entirely.
attention_mask = attention_mask.to(dtype=self.dtype) # fp16 compatibility
# attention_mask = (1.0 - attention_mask) * torch.finfo(self.dtype).min
# Prepare head mask if needed
# 1.0 in head_mask indicate we keep the head
# attention_probs has shape bsz x n_heads x N x N
# input head_mask has shape [num_heads] or [num_hidden_layers x num_heads]
# and head_mask is converted to shape [num_hidden_layers x batch x num_heads x seq_length x seq_length]
head_mask = self.get_head_mask(head_mask, self.config.num_hidden_layers)
if inputs_embeds is None:
inputs_embeds = self.embed_in(input_ids)
hidden_states = inputs_embeds
if self.gradient_checkpointing and self.training:
if use_cache:
logger.warning(
"`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..."
)
use_cache = False
presents = () if use_cache else None
all_attentions = () if output_attentions else None
all_hidden_states = () if output_hidden_states else None
for i, (layer, layer_past) in enumerate(zip(self.layers, past_key_values)):
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
if self.gradient_checkpointing and self.training:
def create_custom_forward(module):
def custom_forward(*inputs):
# None for layer_past
return module(*inputs, use_cache, None, output_attentions)
return custom_forward
outputs = torch.utils.checkpoint.checkpoint(
create_custom_forward(layer),
hidden_states,
attention_mask,
head_mask[i],
)
else:
outputs = layer(
hidden_states,
attention_mask=attention_mask,
head_mask=head_mask[i],
layer_past=layer_past,
use_cache=use_cache,
output_attentions=output_attentions,
)
hidden_states = outputs[0]
if use_cache is True:
presents = presents + (outputs[1],)
if output_attentions:
all_attentions = all_attentions + (outputs[2 if use_cache else 1],)
hidden_states = self.final_layer_norm(hidden_states)
# Add last hidden state
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
if not return_dict:
return tuple(v for v in [hidden_states, presents, all_hidden_states, all_attentions] if v is not None)
ret = BaseModelOutputWithPast(
last_hidden_state=hidden_states,
past_key_values=presents,
hidden_states=all_hidden_states,
attentions=all_attentions,
)
return ret
@add_start_docstrings(
"""GPTJiang Model with a `language modeling` head on top for CLM fine-tuning.""", GPT_JIANG_START_DOCSTRING
)
class GPTJiangForCausalLM(GPTJiangPreTrainedModel):
_keys_to_ignore_on_load_missing = [r"position_ids", r"predictions.decoder.bias"]
def __init__(self, config):
super().__init__(config)
self.gpt_kdf = GPTJiangModel(config)
self.embed_out = nn.Linear(config.hidden_size, config.vocab_size, bias=False)
# Initialize weights and apply final processing
self.post_init()
def get_output_embeddings(self):
return self.embed_out
def set_output_embeddings(self, new_embeddings):
self.embed_out = new_embeddings
@add_start_docstrings_to_model_forward(GPT_JIANG_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
@replace_return_docstrings(output_type=CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC)
def forward(
self,
input_ids: Optional[torch.LongTensor] = None,
attention_mask: Optional[torch.FloatTensor] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
head_mask: Optional[torch.FloatTensor] = None,
past_key_values: Optional[Tuple[Tuple[torch.FloatTensor]]] = None,
labels: Optional[torch.LongTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[Tuple, CausalLMOutputWithPast]:
r"""
past_key_values (`tuple(tuple(torch.FloatTensor))`, *optional*, returned when `use_cache=True` is passed or when `config.use_cache=True`):
Tuple of `tuple(torch.FloatTensor)` of length `config.n_layers`, with each tuple having 2 tensors of shape
`(batch_size, num_heads, sequence_length, embed_size_per_head)`) and 2 additional tensors of shape
`(batch_size, num_heads, encoder_sequence_length, embed_size_per_head)`. The two additional tensors are
only required when the model is used as a decoder in a Sequence to Sequence model.
Contains pre-computed hidden-states (key and values in the self-attention blocks that can be used (see
`past_key_values` input) to speed up sequential decoding.
If `past_key_values` are used, the user can optionally input only the last `decoder_input_ids` (those that
don't have their past key value states given to this model) of shape `(batch_size, 1)` instead of all
`decoder_input_ids` of shape `(batch_size, sequence_length)`.
labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
Labels for computing the left-to-right language modeling loss (next word prediction). Indices should be in
`[-100, 0, ..., config.vocab_size]` (see `input_ids` docstring) Tokens with indices set to `-100` are
ignored (masked), the loss is only computed for the tokens with labels n `[0, ..., config.vocab_size]`.
use_cache (`bool`, *optional*):
If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding (see
`past_key_values`).
Returns:
Example:
```python
>>> from transformers import AutoTokenizer, GPTJiangForCausalLM, GPTJiangConfig
>>> import torch
>>> tokenizer = AutoTokenizer.from_pretrained("EleutherAI/gpt-neox-20b")
>>> config = GPTJiangConfig.from_pretrained("EleutherAI/gpt-neox-20b")
>>> config.is_decoder = True
>>> model = GPTJiangForCausalLM.from_pretrained("EleutherAI/gpt-neox-20b", config=config)
>>> inputs = tokenizer("Hello, my dog is cute", return_tensors="pt")
>>> outputs = model(**inputs)
>>> prediction_logits = outputs.logits
```"""
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
outputs = self.gpt_kdf(
input_ids,
attention_mask=attention_mask,
head_mask=head_mask,
inputs_embeds=inputs_embeds,
past_key_values=past_key_values,
use_cache=use_cache,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
hidden_states = outputs[0]
lm_logits = self.embed_out(hidden_states)
lm_loss = None
attn_output_loss = None
if labels is not None:
# we are doing next-token prediction; shift prediction scores and input ids by one
shift_logits = lm_logits[:, :-1, :].contiguous()
labels = labels[:, 1:].contiguous()
loss_fct = CrossEntropyLoss()
lm_loss = loss_fct(shift_logits.view(-1, shift_logits.size(-1)), labels.view(-1))
if not return_dict:
output = (lm_logits,) + outputs[1:]
return ((lm_loss,) + output) if lm_loss is not None else output
ret = CausalLMOutputWithPast(
loss=lm_loss,
logits=lm_logits,
past_key_values=outputs.past_key_values,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)
return ret
def prepare_inputs_for_generation(self, input_ids, past_key_values=None, attention_mask=None, **model_kwargs):
input_shape = input_ids.shape
# if model is used as a decoder in encoder-decoder model, the decoder attention mask is created on the fly
if attention_mask is None:
attention_mask = input_ids.new_ones(input_shape)
# cut decoder_input_ids if past is used
if past_key_values and past_key_values[0] is not None:
input_ids = input_ids[:, -1:]
return {
"input_ids": input_ids,
"attention_mask": attention_mask,
"past_key_values": past_key_values,
}
def _reorder_cache(self, past_key_values, beam_idx):
reordered_past = ()
for layer_past in past_key_values:
reordered_past += (
tuple(past_state.index_select(0, beam_idx) for past_state in layer_past[:2]) + layer_past[2:],
)
return reordered_past