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- # coding=utf-8
- # Copyright 2022 HuggingFace Inc. team and BigScience workshop.
- #
- # 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 BLOOM model."""
- import math
- import warnings
- from typing import Optional, Union
- import torch
- from torch import nn
- from torch.nn import BCEWithLogitsLoss, CrossEntropyLoss, LayerNorm, MSELoss
- from torch.nn import functional as F
- from ...cache_utils import Cache, DynamicCache, StaticCache
- from ...generation import GenerationMixin
- from ...modeling_attn_mask_utils import AttentionMaskConverter
- from ...modeling_layers import GradientCheckpointingLayer
- from ...modeling_outputs import (
- BaseModelOutputWithPastAndCrossAttentions,
- CausalLMOutputWithCrossAttentions,
- QuestionAnsweringModelOutput,
- SequenceClassifierOutputWithPast,
- TokenClassifierOutput,
- )
- from ...modeling_utils import PreTrainedModel
- from ...utils import (
- auto_docstring,
- is_torch_flex_attn_available,
- logging,
- )
- from .configuration_bloom import BloomConfig
- if is_torch_flex_attn_available():
- from torch.nn.attention.flex_attention import BlockMask
- from ...integrations.flex_attention import make_flex_block_causal_mask
- logger = logging.get_logger(__name__)
- def build_alibi_tensor(attention_mask: torch.Tensor, num_heads: int, dtype: torch.dtype) -> torch.Tensor:
- """
- Link to paper: https://huggingface.co/papers/2108.12409 Alibi tensor is not causal as the original paper mentions, it
- relies on a translation invariance of softmax for quick implementation: with l being a tensor, and a fixed value
- `softmax(l+a) = softmax(l)`. Based on
- https://github.com/ofirpress/attention_with_linear_biases/blob/a35aaca144e0eb6b789dfcb46784c4b8e31b7983/fairseq/models/transformer.py#L742
- TODO @thomasw21 this doesn't work as nicely due to the masking strategy, and so masking varies slightly.
- Args:
- Returns tensor shaped (batch_size * num_heads, 1, max_seq_len)
- attention_mask (`torch.Tensor`):
- Token-wise attention mask, this should be of shape (batch_size, max_seq_len).
- num_heads (`int`):
- number of heads
- dtype (`torch.dtype`, *optional*, default=`torch.bfloat16`):
- dtype of the output tensor
- """
- batch_size, seq_length = attention_mask.shape
- closest_power_of_2 = 2 ** math.floor(math.log2(num_heads))
- base = torch.tensor(
- 2 ** (-(2 ** -(math.log2(closest_power_of_2) - 3))), device=attention_mask.device, dtype=torch.float32
- )
- powers = torch.arange(1, 1 + closest_power_of_2, device=attention_mask.device, dtype=torch.int32)
- slopes = torch.pow(base, powers)
- if closest_power_of_2 != num_heads:
- extra_base = torch.tensor(
- 2 ** (-(2 ** -(math.log2(2 * closest_power_of_2) - 3))), device=attention_mask.device, dtype=torch.float32
- )
- num_remaining_heads = min(closest_power_of_2, num_heads - closest_power_of_2)
- extra_powers = torch.arange(1, 1 + 2 * num_remaining_heads, 2, device=attention_mask.device, dtype=torch.int32)
- slopes = torch.cat([slopes, torch.pow(extra_base, extra_powers)], dim=0)
- # Note: alibi will added to the attention bias that will be applied to the query, key product of attention
- # => therefore alibi will have to be of shape (batch_size, num_heads, query_length, key_length)
- # => here we set (batch_size=1, num_heads=num_heads, query_length=1, key_length=max_length)
- # => the query_length dimension will then be broadcasted correctly
- # This is more or less identical to T5's relative position bias:
- # https://github.com/huggingface/transformers/blob/f681437203baa7671de3174b0fa583c349d9d5e1/src/transformers/models/t5/modeling_t5.py#L527
- arange_tensor = ((attention_mask.cumsum(dim=-1) - 1) * attention_mask)[:, None, :]
- alibi = slopes[..., None] * arange_tensor
- return alibi.reshape(batch_size * num_heads, 1, seq_length).to(dtype)
- def dropout_add(x: torch.Tensor, residual: torch.Tensor, prob: float, training: bool) -> torch.Tensor:
- """
- Dropout add function
- Args:
- x (`torch.tensor`):
- input tensor
- residual (`torch.tensor`):
- residual tensor
- prob (`float`):
- dropout probability
- training (`bool`):
- training mode
- """
- out = F.dropout(x, p=prob, training=training)
- out = residual + out
- return out
- def bloom_gelu_forward(x: torch.Tensor) -> torch.Tensor:
- """
- Custom bias GELU function. Adapted from Megatron-DeepSpeed code. Here we use a simple implementation (inference) to
- make the model jitable.
- Args:
- x (`torch.tensor`):
- input hidden states
- """
- return x * 0.5 * (1.0 + torch.tanh(0.79788456 * x * (1 + 0.044715 * x * x)))
- def bloom_gelu_back(g: torch.Tensor, x: torch.Tensor) -> torch.Tensor:
- """
- gradient of tanh approximation of gelu gradient of actual gelu is: 0.5 * (1. + torch.erf(x * 0.70710678)) +
- 0.3989423 * x * torch.exp(-0.5 * x * x)
- Args:
- g (`torch.tensor`):
- gradient output tensor
- x (`torch.tensor`):
- input tensor
- """
- x = x[0] # x is a tuple of 1 element, needs to unpack it first
- tanh_out = torch.tanh(0.79788456 * x * (1 + 0.044715 * x * x))
- # sqrt(2/pi) * 3 * 0.044715 -> 0.1070322243
- ff = 0.5 * x * ((1 - tanh_out * tanh_out) * (0.79788456 + 0.1070322243 * x * x)) + 0.5 * (1 + tanh_out)
- return ff * g
- class GeLUFunction(torch.autograd.Function):
- @staticmethod
- def forward(ctx, input: torch.Tensor) -> torch.Tensor:
- ctx.save_for_backward(input)
- return bloom_gelu_forward(input)
- @staticmethod
- def backward(ctx, grad_output: torch.Tensor) -> torch.Tensor:
- input = ctx.saved_tensors
- tmp = bloom_gelu_back(grad_output, input)
- return tmp
- class BloomGelu(nn.Module):
- """
- BloomBiasGelu wrapper function that make use of the simple function on inference mode to make the model
- torchscriptable and use the autograd function in training mode to get the accurate results of the gradients Partly
- copied from Megatron-DeepSpeed code and adapted for our needs
- See here why autograd functions are not torchscriptable: https://github.com/pytorch/pytorch/issues/22329
- """
- def __init__(self):
- super().__init__()
- def forward(self, x: torch.Tensor) -> torch.Tensor:
- if self.training:
- return GeLUFunction.apply(x)
- else:
- return bloom_gelu_forward(x)
- class BloomAttention(nn.Module):
- def __init__(self, config: BloomConfig, layer_idx: Optional[int] = None):
- super().__init__()
- self.pretraining_tp = config.pretraining_tp
- self.slow_but_exact = config.slow_but_exact
- self.hidden_size = config.hidden_size
- self.num_heads = config.n_head
- self.head_dim = self.hidden_size // self.num_heads
- self.split_size = self.hidden_size
- self.hidden_dropout = config.hidden_dropout
- if self.head_dim * self.num_heads != self.hidden_size:
- raise ValueError(
- f"`hidden_size` must be divisible by num_heads (got `hidden_size`: {self.hidden_size} and `num_heads`:"
- f" {self.num_heads})."
- )
- # Layer-wise attention scaling
- self.inv_norm_factor = 1.0 / math.sqrt(self.head_dim)
- self.beta = 1.0
- self.layer_idx = layer_idx
- if layer_idx is None:
- logger.warning_once(
- f"Instantiating {self.__class__.__name__} without passing a `layer_idx` is not recommended and will "
- "lead to errors during the forward call if caching is used. Please make sure to provide a `layer_idx` "
- "when creating this class."
- )
- self.query_key_value = nn.Linear(self.hidden_size, 3 * self.hidden_size, bias=True)
- self.dense = nn.Linear(self.hidden_size, self.hidden_size)
- self.attention_dropout = nn.Dropout(config.attention_dropout)
- def _reshape(self, fused_qkv: torch.Tensor) -> tuple[torch.Tensor, torch.Tensor, torch.Tensor]:
- """
- Split the last dimension into (num_heads, head_dim) and reshapes to (bs, heads, len, dim) shape
- without making any copies, results share same memory storage as `fused_qkv`
- Args:
- fused_qkv (`torch.tensor`): [batch_size, seq_length, num_heads * 3 * head_dim]
- Returns:
- query: [batch_size, num_heads, seq_length, head_dim]
- key: [batch_size, num_heads, seq_length, head_dim]
- value: [batch_size, num_heads, seq_length, head_dim]
- """
- batch_size, seq_length, three_times_hidden_size = fused_qkv.shape
- fused_qkv = fused_qkv.view(batch_size, seq_length, self.num_heads, 3, self.head_dim)
- query_layer = fused_qkv[..., 0, :].transpose(1, 2)
- key_layer = fused_qkv[..., 1, :].transpose(1, 2)
- value_layer = fused_qkv[..., 2, :].transpose(1, 2)
- return query_layer, key_layer, value_layer
- def _merge_heads(self, x: torch.Tensor) -> torch.Tensor:
- """
- Merge heads together over the last dimension
- Args:
- x (`torch.tensor`): [batch_size * num_heads, seq_length, head_dim]
- Returns:
- torch.tensor: [batch_size, seq_length, num_heads * head_dim]
- """
- # What we want to achieve is:
- # batch_size * num_heads, seq_length, head_dim -> batch_size, seq_length, num_heads * head_dim
- batch_size_and_num_heads, seq_length, _ = x.shape
- batch_size = batch_size_and_num_heads // self.num_heads
- # First view to decompose the batch size
- # batch_size * num_heads, seq_length, head_dim -> batch_size, num_heads, seq_length, head_dim
- x = x.view(batch_size, self.num_heads, seq_length, self.head_dim)
- # batch_size, num_heads, seq_length, head_dim -> batch_size, seq_length, num_heads, head_dim
- x = x.permute(0, 2, 1, 3)
- # batch_size, seq_length, num_heads, head_dim -> batch_size, seq_length, num_heads * head_dim
- return x.reshape(batch_size, seq_length, self.num_heads * self.head_dim)
- def forward(
- self,
- hidden_states: torch.Tensor,
- residual: torch.Tensor,
- alibi: torch.Tensor,
- attention_mask: torch.Tensor,
- layer_past: Optional[Cache] = None,
- head_mask: Optional[torch.Tensor] = None,
- use_cache: bool = False,
- output_attentions: bool = False,
- cache_position: Optional[torch.LongTensor] = None,
- ):
- batch_size, q_length, _ = hidden_states.shape
- fused_qkv = self.query_key_value(hidden_states) # [batch_size, seq_length, 3 x hidden_size]
- # 3 x [batch_size, num_heads, seq_length, head_dim]
- query_layer, key_layer, value_layer = self._reshape(fused_qkv)
- if layer_past is not None:
- cache_kwargs = {"cache_position": cache_position}
- key_layer, value_layer = layer_past.update(key_layer, value_layer, self.layer_idx, cache_kwargs)
- # reshape qkv for further computations
- query_layer = query_layer.reshape(batch_size * self.num_heads, -1, self.head_dim)
- key_layer = key_layer.reshape(batch_size * self.num_heads, -1, self.head_dim).transpose(-1, -2)
- value_layer = value_layer.reshape(batch_size * self.num_heads, -1, self.head_dim)
- # [batch_size * num_heads, q_length, kv_length]
- attention_scores = alibi.baddbmm(
- batch1=query_layer,
- batch2=key_layer,
- beta=self.beta,
- alpha=self.inv_norm_factor,
- )
- # change view to [batch_size, num_heads, q_length, kv_length]
- attn_weights = attention_scores.view(batch_size, self.num_heads, q_length, -1)
- if attention_mask is not None: # no matter the length, we just slice it
- causal_mask = attention_mask[:, :, :, : key_layer.shape[-1]]
- attn_weights = attn_weights + causal_mask
- # cast attention scores to fp32, compute scaled softmax and cast back to initial dtype
- attention_probs = F.softmax(attn_weights, dim=-1, dtype=torch.float32).to(query_layer.dtype)
- # [batch_size, num_heads, q_length, kv_length]
- attention_probs = self.attention_dropout(attention_probs)
- if head_mask is not None:
- attention_probs = attention_probs * head_mask
- # change view [batch_size x num_heads, q_length, kv_length]
- attention_probs_reshaped = attention_probs.view(batch_size * self.num_heads, q_length, -1)
- # matmul: [batch_size * num_heads, q_length, head_dim]
- context_layer = torch.bmm(attention_probs_reshaped, value_layer)
- # change view [batch_size, q_length, num_heads * head_dim]
- context_layer = self._merge_heads(context_layer)
- # aggregate results across tp ranks. See here: https://github.com/pytorch/pytorch/issues/76232
- if self.pretraining_tp > 1 and self.slow_but_exact:
- slices = self.hidden_size / self.pretraining_tp
- output_tensor = torch.zeros_like(context_layer)
- for i in range(self.pretraining_tp):
- output_tensor = output_tensor + F.linear(
- context_layer[:, :, int(i * slices) : int((i + 1) * slices)],
- self.dense.weight[:, int(i * slices) : int((i + 1) * slices)],
- )
- else:
- output_tensor = self.dense(context_layer)
- output_tensor = dropout_add(output_tensor, residual, self.hidden_dropout, self.training)
- return output_tensor, attention_probs
- class BloomMLP(nn.Module):
- def __init__(self, config: BloomConfig):
- super().__init__()
- hidden_size = config.hidden_size
- self.pretraining_tp = config.pretraining_tp
- self.slow_but_exact = config.slow_but_exact
- self.dense_h_to_4h = nn.Linear(hidden_size, 4 * hidden_size)
- self.gelu_impl = BloomGelu()
- self.dense_4h_to_h = nn.Linear(4 * hidden_size, hidden_size)
- self.hidden_dropout = config.hidden_dropout
- def forward(self, hidden_states: torch.Tensor, residual: torch.Tensor) -> torch.Tensor:
- hidden_states = self.gelu_impl(self.dense_h_to_4h(hidden_states))
- if self.pretraining_tp > 1 and self.slow_but_exact:
- intermediate_output = torch.zeros_like(residual)
- slices = self.dense_4h_to_h.weight.shape[-1] / self.pretraining_tp
- for i in range(self.pretraining_tp):
- intermediate_output = intermediate_output + F.linear(
- hidden_states[:, :, int(i * slices) : int((i + 1) * slices)],
- self.dense_4h_to_h.weight[:, int(i * slices) : int((i + 1) * slices)],
- )
- else:
- intermediate_output = self.dense_4h_to_h(hidden_states)
- output = dropout_add(intermediate_output, residual, self.hidden_dropout, self.training)
- return output
- class BloomBlock(GradientCheckpointingLayer):
- def __init__(self, config: BloomConfig, layer_idx: Optional[int] = None):
- super().__init__()
- hidden_size = config.hidden_size
- self.input_layernorm = LayerNorm(hidden_size, eps=config.layer_norm_epsilon)
- self.num_heads = config.n_head
- self.self_attention = BloomAttention(config, layer_idx)
- self.post_attention_layernorm = LayerNorm(hidden_size, eps=config.layer_norm_epsilon)
- self.mlp = BloomMLP(config)
- self.apply_residual_connection_post_layernorm = config.apply_residual_connection_post_layernorm
- self.hidden_dropout = config.hidden_dropout
- def forward(
- self,
- hidden_states: torch.Tensor,
- alibi: torch.Tensor,
- attention_mask: torch.Tensor,
- layer_past: Optional[Cache] = None,
- head_mask: Optional[torch.Tensor] = None,
- use_cache: bool = False,
- output_attentions: bool = False,
- cache_position: Optional[torch.LongTensor] = None,
- ):
- # hidden_states: [batch_size, seq_length, hidden_size]
- # Layer norm at the beginning of the transformer layer.
- layernorm_output = self.input_layernorm(hidden_states)
- # Layer norm post the self attention.
- if self.apply_residual_connection_post_layernorm:
- residual = layernorm_output
- else:
- residual = hidden_states
- # Self attention.
- attention_output, attn_weights = self.self_attention(
- layernorm_output,
- residual,
- layer_past=layer_past,
- attention_mask=attention_mask,
- alibi=alibi,
- head_mask=head_mask,
- use_cache=use_cache,
- output_attentions=output_attentions,
- cache_position=cache_position,
- )
- layernorm_output = self.post_attention_layernorm(attention_output)
- # Get residual
- if self.apply_residual_connection_post_layernorm:
- residual = layernorm_output
- else:
- residual = attention_output
- # MLP.
- output = self.mlp(layernorm_output, residual)
- return output, attn_weights # hidden_states, attentions
- @auto_docstring
- class BloomPreTrainedModel(PreTrainedModel):
- config: BloomConfig
- base_model_prefix = "transformer"
- supports_gradient_checkpointing = True
- _no_split_modules = ["BloomBlock"]
- _skip_keys_device_placement = "past_key_values"
- _can_compile_fullgraph = True
- def __init__(self, *inputs, **kwargs):
- super().__init__(*inputs, **kwargs)
- def _init_weights(self, module: nn.Module):
- """Initialize the weights."""
- if isinstance(module, nn.Linear):
- # Slightly different from the TF version which uses truncated_normal for initialization
- # cf https://github.com/pytorch/pytorch/pull/5617
- 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, LayerNorm):
- module.bias.data.zero_()
- module.weight.data.fill_(1.0)
- @auto_docstring
- class BloomModel(BloomPreTrainedModel):
- def __init__(self, config: BloomConfig):
- super().__init__(config)
- self.embed_dim = config.hidden_size
- self.num_heads = config.n_head
- # Embedding + LN Embedding
- self.word_embeddings = nn.Embedding(config.vocab_size, self.embed_dim)
- self.word_embeddings_layernorm = LayerNorm(self.embed_dim, eps=config.layer_norm_epsilon)
- # Transformer blocks
- self.h = nn.ModuleList([BloomBlock(config, layer_idx=i) for i in range(config.num_hidden_layers)])
- # Final Layer Norm
- self.ln_f = LayerNorm(self.embed_dim, eps=config.layer_norm_epsilon)
- self.gradient_checkpointing = False
- # Initialize weights and apply final processing
- self.post_init()
- def build_alibi_tensor(self, attention_mask: torch.Tensor, num_heads: int, dtype: torch.dtype) -> torch.Tensor:
- return build_alibi_tensor(attention_mask, num_heads, dtype)
- def get_input_embeddings(self):
- return self.word_embeddings
- def set_input_embeddings(self, new_embeddings: torch.Tensor):
- self.word_embeddings = new_embeddings
- @auto_docstring
- def forward(
- self,
- input_ids: Optional[torch.LongTensor] = None,
- past_key_values: Optional[Union[Cache, tuple[tuple[torch.Tensor, torch.Tensor], ...]]] = None,
- attention_mask: Optional[torch.Tensor] = None,
- head_mask: Optional[torch.LongTensor] = None,
- inputs_embeds: 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,
- cache_position: Optional[torch.LongTensor] = None,
- **deprecated_arguments,
- ) -> Union[tuple[torch.Tensor, ...], BaseModelOutputWithPastAndCrossAttentions]:
- r"""
- input_ids (`torch.LongTensor` of shape `(batch_size, input_ids_length)`):
- `input_ids_length` = `sequence_length` if `past_key_values` is `None` else `past_key_values.get_seq_length()`
- (`sequence_length` of input past key value states). Indices of input sequence tokens in the vocabulary.
- If `past_key_values` is used, only `input_ids` that do not have their past calculated should be passed as
- `input_ids`.
- Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
- [`PreTrainedTokenizer.__call__`] for details.
- [What are input IDs?](../glossary#input-ids)
- """
- if deprecated_arguments.pop("position_ids", False) is not False:
- # `position_ids` could have been `torch.Tensor` or `None` so defaulting pop to `False` allows to detect if users were passing explicitly `None`
- warnings.warn(
- "`position_ids` have no functionality in BLOOM and will be removed in v5.0.0. You can safely ignore"
- " passing `position_ids`.",
- FutureWarning,
- )
- if len(deprecated_arguments) > 0:
- raise ValueError(f"Got unexpected arguments: {deprecated_arguments}")
- 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
- )
- use_cache = use_cache if use_cache is not None else self.config.use_cache
- return_dict = return_dict if return_dict is not None else self.config.use_return_dict
- if (input_ids is None) ^ (inputs_embeds is not None):
- raise ValueError("You must specify exactly one of input_ids or inputs_embeds")
- if self.gradient_checkpointing and self.training and use_cache:
- logger.warning_once(
- "`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..."
- )
- use_cache = False
- if inputs_embeds is None:
- inputs_embeds = self.word_embeddings(input_ids)
- if use_cache and past_key_values is None:
- past_key_values = DynamicCache(config=self.config)
- batch_size, seq_length, _ = inputs_embeds.shape
- past_length = past_key_values.get_seq_length() if past_key_values is not None else 0
- seq_length_with_past = seq_length + past_length
- if cache_position is None:
- cache_position = torch.arange(past_length, past_length + seq_length, device=inputs_embeds.device)
- # Prepare head mask if needed
- # 1.0 in head_mask indicate we keep the head
- # attention_probs has shape batch_size x num_heads x N x N
- # head_mask has shape n_layer x batch x num_heads x N x N
- head_mask = self.get_head_mask(head_mask, self.config.n_layer)
- hidden_states = self.word_embeddings_layernorm(inputs_embeds)
- all_self_attentions = () if output_attentions else None
- all_hidden_states = () if output_hidden_states else None
- # Compute alibi tensor: check build_alibi_tensor documentation
- if attention_mask is None:
- attention_mask = torch.ones((batch_size, seq_length_with_past), device=hidden_states.device)
- else:
- attention_mask = attention_mask.to(hidden_states.device)
- alibi = self.build_alibi_tensor(attention_mask, self.num_heads, dtype=hidden_states.dtype)
- causal_mask = self._update_causal_mask(
- attention_mask, inputs_embeds, cache_position, past_key_values, output_attentions
- )
- for i, block in enumerate(self.h):
- if output_hidden_states:
- all_hidden_states = all_hidden_states + (hidden_states,)
- outputs = block(
- hidden_states,
- layer_past=past_key_values,
- attention_mask=causal_mask,
- head_mask=head_mask[i],
- use_cache=use_cache,
- output_attentions=output_attentions,
- alibi=alibi,
- cache_position=cache_position,
- )
- hidden_states = outputs[0]
- if output_attentions:
- all_self_attentions = all_self_attentions + (outputs[1],)
- # Add last hidden state
- hidden_states = self.ln_f(hidden_states)
- if output_hidden_states:
- all_hidden_states = all_hidden_states + (hidden_states,)
- if not return_dict:
- return tuple(
- v for v in [hidden_states, past_key_values, all_hidden_states, all_self_attentions] if v is not None
- )
- return BaseModelOutputWithPastAndCrossAttentions(
- last_hidden_state=hidden_states,
- past_key_values=past_key_values,
- hidden_states=all_hidden_states,
- attentions=all_self_attentions,
- )
- # Copied from transformers.models.gptj.modeling_gptj.GPTJModel._update_causal_mask
- def _update_causal_mask(
- self,
- attention_mask: Union[torch.Tensor, "BlockMask"],
- input_tensor: torch.Tensor,
- cache_position: torch.Tensor,
- past_key_values: Cache,
- output_attentions: bool = False,
- ):
- if self.config._attn_implementation == "flash_attention_2":
- if attention_mask is not None and (attention_mask == 0.0).any():
- return attention_mask
- return None
- if self.config._attn_implementation == "flex_attention":
- if isinstance(attention_mask, torch.Tensor):
- attention_mask = make_flex_block_causal_mask(attention_mask)
- return attention_mask
- # For SDPA, when possible, we will rely on its `is_causal` argument instead of its `attn_mask` argument, in
- # order to dispatch on Flash Attention 2. This feature is not compatible with static cache, as SDPA will fail
- # to infer the attention mask.
- past_seen_tokens = past_key_values.get_seq_length() if past_key_values is not None else 0
- using_compilable_cache = past_key_values.is_compileable if past_key_values is not None else False
- # When output attentions is True, sdpa implementation's forward method calls the eager implementation's forward
- if self.config._attn_implementation == "sdpa" and not using_compilable_cache and not output_attentions:
- if AttentionMaskConverter._ignore_causal_mask_sdpa(
- attention_mask,
- inputs_embeds=input_tensor,
- past_key_values_length=past_seen_tokens,
- is_training=self.training,
- ):
- return None
- dtype = input_tensor.dtype
- sequence_length = input_tensor.shape[1]
- if using_compilable_cache:
- target_length = past_key_values.get_max_cache_shape()
- else:
- target_length = (
- attention_mask.shape[-1]
- if isinstance(attention_mask, torch.Tensor)
- else past_seen_tokens + sequence_length + 1
- )
- # In case the provided `attention` mask is 2D, we generate a causal mask here (4D).
- causal_mask = self._prepare_4d_causal_attention_mask_with_cache_position(
- attention_mask,
- sequence_length=sequence_length,
- target_length=target_length,
- dtype=dtype,
- cache_position=cache_position,
- batch_size=input_tensor.shape[0],
- )
- if (
- self.config._attn_implementation == "sdpa"
- and attention_mask is not None
- and attention_mask.device.type in ["cuda", "xpu", "npu"]
- and not output_attentions
- ):
- # Attend to all tokens in fully masked rows in the causal_mask, for example the relevant first rows when
- # using left padding. This is required by F.scaled_dot_product_attention memory-efficient attention path.
- # Details: https://github.com/pytorch/pytorch/issues/110213
- min_dtype = torch.finfo(dtype).min
- causal_mask = AttentionMaskConverter._unmask_unattended(causal_mask, min_dtype)
- return causal_mask
- @staticmethod
- # Copied from transformers.models.gptj.modeling_gptj.GPTJModel._prepare_4d_causal_attention_mask_with_cache_position
- def _prepare_4d_causal_attention_mask_with_cache_position(
- attention_mask: torch.Tensor,
- sequence_length: int,
- target_length: int,
- dtype: torch.dtype,
- cache_position: torch.Tensor,
- batch_size: int,
- **kwargs,
- ):
- """
- Creates a causal 4D mask of shape `(batch_size, 1, query_length, key_value_length)` from a 2D mask of shape
- `(batch_size, key_value_length)`, or if the input `attention_mask` is already 4D, do nothing.
- Args:
- attention_mask (`torch.Tensor`):
- A 2D attention mask of shape `(batch_size, key_value_length)` or a 4D attention mask of shape
- `(batch_size, 1, query_length, key_value_length)`.
- sequence_length (`int`):
- The sequence length being processed.
- target_length (`int`):
- The target length: when generating with static cache, the mask should be as long as the static cache,
- to account for the 0 padding, the part of the cache that is not filled yet.
- dtype (`torch.dtype`):
- The dtype to use for the 4D attention mask.
- cache_position (`torch.Tensor`):
- Indices depicting the position of the input sequence tokens in the sequence.
- batch_size (`torch.Tensor`):
- Batch size.
- """
- if attention_mask is not None and attention_mask.dim() == 4:
- # In this case we assume that the mask comes already in inverted form and requires no inversion or slicing.
- causal_mask = attention_mask
- else:
- min_dtype = torch.finfo(dtype).min
- causal_mask = torch.full(
- (sequence_length, target_length), fill_value=min_dtype, dtype=dtype, device=cache_position.device
- )
- if sequence_length != 1:
- causal_mask = torch.triu(causal_mask, diagonal=1)
- causal_mask *= torch.arange(target_length, device=cache_position.device) > cache_position.reshape(-1, 1)
- causal_mask = causal_mask[None, None, :, :].expand(batch_size, 1, -1, -1)
- if attention_mask is not None:
- causal_mask = causal_mask.clone() # copy to contiguous memory for in-place edit
- mask_length = attention_mask.shape[-1]
- padding_mask = causal_mask[:, :, :, :mask_length] + attention_mask[:, None, None, :].to(
- causal_mask.device
- )
- padding_mask = padding_mask == 0
- causal_mask[:, :, :, :mask_length] = causal_mask[:, :, :, :mask_length].masked_fill(
- padding_mask, min_dtype
- )
- return causal_mask
- @auto_docstring(
- custom_intro="""
- The Bloom Model transformer with a language modeling head on top (linear layer with weights tied to the input
- embeddings).
- """
- )
- class BloomForCausalLM(BloomPreTrainedModel, GenerationMixin):
- _tied_weights_keys = ["lm_head.weight"]
- def __init__(self, config: BloomConfig):
- super().__init__(config)
- self.transformer = BloomModel(config)
- self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False)
- # Initialize weights and apply final processing
- self.post_init()
- def set_output_embeddings(self, new_embeddings: torch.Tensor):
- self.lm_head = new_embeddings
- def prepare_inputs_for_generation(
- self,
- input_ids,
- past_key_values=None,
- attention_mask=None,
- inputs_embeds=None,
- cache_position=None,
- use_cache=True,
- **kwargs,
- ):
- # Overwritten because of the fixed-shape attention mask creation
- # If we have cache: let's slice `input_ids` through `cache_position`, to keep only the unprocessed tokens
- # Exception 1: when passing input_embeds, input_ids may be missing entries
- # Exception 2: some generation methods do special slicing of input_ids, so we don't need to do it here
- # Exception 3: with synced GPUs cache_position may go out of bounds, but we only want dummy token in that case.
- # (we can't check exception 3 while compiling)
- # Exception 4: If input_embeds are passed then slice it through `cache_position`, to keep only the unprocessed tokens and
- # generate the first token for each sequence. Later use the generated Input ids for continuation.
- if past_key_values is not None:
- if inputs_embeds is not None and input_ids.shape[1] == 0: # Exception 4
- inputs_embeds = inputs_embeds[:, -cache_position.shape[0] :]
- elif (
- inputs_embeds is not None # Exception 1
- or cache_position[-1] >= input_ids.shape[1] # Exception 3
- ):
- input_ids = input_ids[:, -cache_position.shape[0] :]
- elif input_ids.shape[1] != cache_position.shape[0]: # Default case (the "else", a no op, is Exception 2)
- input_ids = input_ids[:, cache_position]
- # if `inputs_embeds` are passed, we only want to use them in the 1st generation step
- if inputs_embeds is not None and len(cache_position) == inputs_embeds.shape[1]:
- model_inputs = {"inputs_embeds": inputs_embeds, "input_ids": None}
- else:
- # This `clone` call is needed to avoid recapturing cuda graphs with `torch.compile`'s `mode="reduce-overhead`, as otherwise the
- # input `position_ids` would have various stride during the decoding. Here, simply using `.contiguous()` is not sufficient as in
- # the batch size = 1 case, `position_ids` is already contiguous but with varying stride which retriggers a capture.
- model_inputs = {"input_ids": input_ids.clone(memory_format=torch.contiguous_format), "inputs_embeds": None}
- # This part differs from other models because BLOOM needs a 2D mask to construct alibi tensor
- # The only difference is the usage of 2D instead of 4D mask, but the shape will be static
- if isinstance(past_key_values, StaticCache) and attention_mask is not None:
- target_length = past_key_values.get_max_cache_shape()
- batch_size, seq_length = attention_mask.shape
- diff = target_length - seq_length
- new_attn_mask = torch.zeros(batch_size, diff, device=attention_mask.device, dtype=attention_mask.dtype)
- attention_mask = torch.cat(
- [attention_mask, new_attn_mask],
- dim=-1,
- )
- model_inputs.update(
- {
- "cache_position": cache_position,
- "past_key_values": past_key_values,
- "use_cache": use_cache,
- "attention_mask": attention_mask,
- }
- )
- # Forward ALL kwargs that are uninitialized (e.g. `use_cache`).
- for key, value in kwargs.items():
- if key not in model_inputs:
- model_inputs[key] = value
- return model_inputs
- @auto_docstring
- def forward(
- self,
- input_ids: Optional[torch.LongTensor] = None,
- past_key_values: Optional[Union[Cache, tuple[tuple[torch.Tensor, torch.Tensor], ...]]] = None,
- attention_mask: Optional[torch.Tensor] = None,
- head_mask: Optional[torch.Tensor] = None,
- inputs_embeds: Optional[torch.Tensor] = None,
- labels: Optional[torch.Tensor] = None,
- use_cache: Optional[bool] = None,
- output_attentions: Optional[bool] = None,
- output_hidden_states: Optional[bool] = None,
- return_dict: Optional[bool] = None,
- cache_position: Optional[torch.LongTensor] = None,
- **deprecated_arguments,
- ) -> Union[tuple[torch.Tensor], CausalLMOutputWithCrossAttentions]:
- r"""
- input_ids (`torch.LongTensor` of shape `(batch_size, input_ids_length)`):
- `input_ids_length` = `sequence_length` if `past_key_values` is `None` else `past_key_values.get_seq_length()`
- (`sequence_length` of input past key value states). Indices of input sequence tokens in the vocabulary.
- If `past_key_values` is used, only `input_ids` that do not have their past calculated should be passed as
- `input_ids`.
- Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
- [`PreTrainedTokenizer.__call__`] for details.
- [What are input IDs?](../glossary#input-ids)
- labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
- Labels for language modeling. Note that the labels **are shifted** inside the model, i.e. you can set
- `labels = input_ids` Indices are selected in `[-100, 0, ..., config.vocab_size]` All labels set to `-100`
- are ignored (masked), the loss is only computed for labels in `[0, ..., config.vocab_size]`
- """
- # Bloom has deprecated kwargs, so we need to pop num_items_in_batch explicitly
- num_items_in_batch = deprecated_arguments.pop("num_items_in_batch", None)
- if deprecated_arguments.pop("position_ids", False) is not False:
- # `position_ids` could have been `torch.Tensor` or `None` so defaulting pop to `False` allows to detect if users were passing explicitly `None`
- warnings.warn(
- "`position_ids` have no functionality in BLOOM and will be removed in v5.0.0. You can safely ignore"
- " passing `position_ids`.",
- FutureWarning,
- )
- if len(deprecated_arguments) > 0:
- raise ValueError(f"Got unexpected arguments: {deprecated_arguments}")
- return_dict = return_dict if return_dict is not None else self.config.use_return_dict
- transformer_outputs = self.transformer(
- input_ids,
- past_key_values=past_key_values,
- attention_mask=attention_mask,
- head_mask=head_mask,
- inputs_embeds=inputs_embeds,
- use_cache=use_cache,
- output_attentions=output_attentions,
- output_hidden_states=output_hidden_states,
- return_dict=return_dict,
- cache_position=cache_position,
- )
- hidden_states = transformer_outputs[0]
- lm_logits = self.lm_head(hidden_states)
- loss = None
- if labels is not None:
- # move labels to correct device to enable model parallelism
- labels = labels.to(lm_logits.device)
- # Flatten the tokens
- loss = self.loss_function(
- lm_logits,
- labels,
- vocab_size=self.config.vocab_size,
- num_items_in_batch=num_items_in_batch,
- )
- if not return_dict:
- output = (lm_logits,) + transformer_outputs[1:]
- return ((loss,) + output) if loss is not None else output
- return CausalLMOutputWithCrossAttentions(
- loss=loss,
- logits=lm_logits,
- past_key_values=transformer_outputs.past_key_values,
- hidden_states=transformer_outputs.hidden_states,
- attentions=transformer_outputs.attentions,
- )
- @auto_docstring(
- custom_intro="""
- The Bloom Model transformer with a sequence classification head on top (linear layer).
- [`BloomForSequenceClassification`] uses the last token in order to do the classification, as other causal models
- (e.g. GPT-1) do.
- Since it does classification on the last token, it requires to know the position of the last token. If a
- `pad_token_id` is defined in the configuration, it finds the last token that is not a padding token in each row. If
- no `pad_token_id` is defined, it simply takes the last value in each row of the batch. Since it cannot guess the
- padding tokens when `inputs_embeds` are passed instead of `input_ids`, it does the same (take the last value in
- each row of the batch).
- """
- )
- class BloomForSequenceClassification(BloomPreTrainedModel):
- def __init__(self, config: BloomConfig):
- super().__init__(config)
- self.num_labels = config.num_labels
- self.transformer = BloomModel(config)
- self.score = nn.Linear(config.hidden_size, config.num_labels, bias=False)
- # Initialize weights and apply final processing
- self.post_init()
- @auto_docstring
- def forward(
- self,
- input_ids: Optional[torch.LongTensor] = None,
- past_key_values: Optional[Union[Cache, tuple[tuple[torch.Tensor, torch.Tensor], ...]]] = None,
- attention_mask: Optional[torch.Tensor] = None,
- head_mask: Optional[torch.Tensor] = None,
- inputs_embeds: Optional[torch.Tensor] = None,
- labels: Optional[torch.Tensor] = None,
- use_cache: Optional[bool] = None,
- output_attentions: Optional[bool] = None,
- output_hidden_states: Optional[bool] = None,
- return_dict: Optional[bool] = None,
- **deprecated_arguments,
- ) -> Union[tuple[torch.Tensor], SequenceClassifierOutputWithPast]:
- r"""
- input_ids (`torch.LongTensor` of shape `(batch_size, input_ids_length)`):
- `input_ids_length` = `sequence_length` if `past_key_values` is `None` else `past_key_values.get_seq_length()`
- (`sequence_length` of input past key value states). Indices of input sequence tokens in the vocabulary.
- If `past_key_values` is used, only `input_ids` that do not have their past calculated should be passed as
- `input_ids`.
- Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
- [`PreTrainedTokenizer.__call__`] for details.
- [What are input IDs?](../glossary#input-ids)
- labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
- Labels for computing the sequence classification/regression loss. Indices should be in `[0, ...,
- config.num_labels - 1]`. If `config.num_labels == 1` a regression loss is computed (Mean-Square loss), If
- `config.num_labels > 1` a classification loss is computed (Cross-Entropy).
- """
- if deprecated_arguments.pop("position_ids", False) is not False:
- # `position_ids` could have been `torch.Tensor` or `None` so defaulting pop to `False` allows to detect if users were passing explicitly `None`
- warnings.warn(
- "`position_ids` have no functionality in BLOOM and will be removed in v5.0.0. You can safely ignore"
- " passing `position_ids`.",
- FutureWarning,
- )
- if len(deprecated_arguments) > 0:
- raise ValueError(f"Got unexpected arguments: {deprecated_arguments}")
- return_dict = return_dict if return_dict is not None else self.config.use_return_dict
- transformer_outputs = self.transformer(
- input_ids,
- past_key_values=past_key_values,
- attention_mask=attention_mask,
- head_mask=head_mask,
- inputs_embeds=inputs_embeds,
- use_cache=use_cache,
- output_attentions=output_attentions,
- output_hidden_states=output_hidden_states,
- return_dict=return_dict,
- )
- hidden_states = transformer_outputs[0]
- logits = self.score(hidden_states)
- if input_ids is not None:
- batch_size = input_ids.shape[0]
- else:
- batch_size = inputs_embeds.shape[0]
- if self.config.pad_token_id is None and batch_size != 1:
- raise ValueError("Cannot handle batch sizes > 1 if no padding token is defined.")
- if self.config.pad_token_id is None:
- last_non_pad_token = -1
- elif input_ids is not None:
- # To handle both left- and right- padding, we take the rightmost token that is not equal to pad_token_id
- non_pad_mask = (input_ids != self.config.pad_token_id).to(logits.device, torch.int32)
- token_indices = torch.arange(input_ids.shape[-1], device=logits.device, dtype=torch.int32)
- last_non_pad_token = (token_indices * non_pad_mask).argmax(-1)
- else:
- last_non_pad_token = -1
- logger.warning_once(
- f"{self.__class__.__name__} will not detect padding tokens in `inputs_embeds`. Results may be "
- "unexpected if using padding tokens in conjunction with `inputs_embeds.`"
- )
- pooled_logits = logits[torch.arange(batch_size, device=logits.device), last_non_pad_token]
- loss = None
- if labels is not None:
- if self.config.problem_type is None:
- if self.num_labels == 1:
- self.config.problem_type = "regression"
- elif self.num_labels > 1 and (labels.dtype == torch.long or labels.dtype == torch.int):
- self.config.problem_type = "single_label_classification"
- else:
- self.config.problem_type = "multi_label_classification"
- if self.config.problem_type == "regression":
- loss_fct = MSELoss()
- if self.num_labels == 1:
- loss = loss_fct(pooled_logits.squeeze(), labels.squeeze())
- else:
- loss = loss_fct(pooled_logits, labels)
- elif self.config.problem_type == "single_label_classification":
- loss_fct = CrossEntropyLoss()
- loss = loss_fct(pooled_logits, labels)
- elif self.config.problem_type == "multi_label_classification":
- loss_fct = BCEWithLogitsLoss()
- loss = loss_fct(pooled_logits, labels)
- if not return_dict:
- output = (pooled_logits,) + transformer_outputs[1:]
- return ((loss,) + output) if loss is not None else output
- return SequenceClassifierOutputWithPast(
- loss=loss,
- logits=pooled_logits,
- past_key_values=transformer_outputs.past_key_values,
- hidden_states=transformer_outputs.hidden_states,
- attentions=transformer_outputs.attentions,
- )
- @auto_docstring
- class BloomForTokenClassification(BloomPreTrainedModel):
- def __init__(self, config: BloomConfig):
- super().__init__(config)
- self.num_labels = config.num_labels
- self.transformer = BloomModel(config)
- if hasattr(config, "classifier_dropout") and config.classifier_dropout is not None:
- classifier_dropout = config.classifier_dropout
- elif hasattr(config, "hidden_dropout") and config.hidden_dropout is not None:
- classifier_dropout = config.hidden_dropout
- else:
- classifier_dropout = 0.1
- self.dropout = nn.Dropout(classifier_dropout)
- self.classifier = nn.Linear(config.hidden_size, config.num_labels)
- # Initialize weights and apply final processing
- self.post_init()
- @auto_docstring
- def forward(
- self,
- input_ids: Optional[torch.LongTensor] = None,
- past_key_values: Optional[Union[Cache, tuple[tuple[torch.Tensor, torch.Tensor], ...]]] = None,
- attention_mask: Optional[torch.Tensor] = None,
- head_mask: Optional[torch.Tensor] = None,
- inputs_embeds: Optional[torch.Tensor] = None,
- labels: Optional[torch.Tensor] = None,
- use_cache: Optional[bool] = None,
- output_attentions: Optional[bool] = None,
- output_hidden_states: Optional[bool] = None,
- return_dict: Optional[bool] = None,
- **deprecated_arguments,
- ) -> Union[tuple[torch.Tensor], TokenClassifierOutput]:
- r"""
- input_ids (`torch.LongTensor` of shape `(batch_size, input_ids_length)`):
- `input_ids_length` = `sequence_length` if `past_key_values` is `None` else `past_key_values.get_seq_length()`
- (`sequence_length` of input past key value states). Indices of input sequence tokens in the vocabulary.
- If `past_key_values` is used, only `input_ids` that do not have their past calculated should be passed as
- `input_ids`.
- Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
- [`PreTrainedTokenizer.__call__`] for details.
- [What are input IDs?](../glossary#input-ids)
- labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
- Labels for computing the sequence classification/regression loss. Indices should be in `[0, ...,
- config.num_labels - 1]`. If `config.num_labels == 1` a regression loss is computed (Mean-Square loss), If
- `config.num_labels > 1` a classification loss is computed (Cross-Entropy).
- """
- if deprecated_arguments.pop("position_ids", False) is not False:
- # `position_ids` could have been `torch.Tensor` or `None` so defaulting pop to `False` allows to detect if users were passing explicitly `None`
- warnings.warn(
- "`position_ids` have no functionality in BLOOM and will be removed in v5.0.0. You can safely ignore"
- " passing `position_ids`.",
- FutureWarning,
- )
- if len(deprecated_arguments) > 0:
- raise ValueError(f"Got unexpected arguments: {deprecated_arguments}")
- return_dict = return_dict if return_dict is not None else self.config.use_return_dict
- transformer_outputs = self.transformer(
- input_ids,
- past_key_values=past_key_values,
- attention_mask=attention_mask,
- head_mask=head_mask,
- inputs_embeds=inputs_embeds,
- use_cache=use_cache,
- output_attentions=output_attentions,
- output_hidden_states=output_hidden_states,
- return_dict=return_dict,
- )
- hidden_states = transformer_outputs[0]
- hidden_states = self.dropout(hidden_states)
- logits = self.classifier(hidden_states)
- loss = None
- if labels is not None:
- # move labels to correct device to enable model parallelism
- labels = labels.to(logits.device)
- batch_size, seq_length = labels.shape
- loss_fct = CrossEntropyLoss()
- loss = loss_fct(
- logits.view(batch_size * seq_length, self.num_labels), labels.view(batch_size * seq_length)
- )
- if not return_dict:
- output = (logits,) + transformer_outputs[2:]
- return ((loss,) + output) if loss is not None else output
- return TokenClassifierOutput(
- loss=loss,
- logits=logits,
- hidden_states=transformer_outputs.hidden_states,
- attentions=transformer_outputs.attentions,
- )
- @auto_docstring
- class BloomForQuestionAnswering(BloomPreTrainedModel):
- def __init__(self, config):
- super().__init__(config)
- self.transformer = BloomModel(config)
- self.qa_outputs = nn.Linear(config.hidden_size, 2)
- # Initialize weights and apply final processing
- self.post_init()
- @auto_docstring
- def forward(
- self,
- input_ids: Optional[torch.LongTensor] = None,
- attention_mask: Optional[torch.FloatTensor] = None,
- position_ids: Optional[torch.LongTensor] = None,
- head_mask: Optional[torch.FloatTensor] = None,
- inputs_embeds: Optional[torch.FloatTensor] = None,
- start_positions: Optional[torch.LongTensor] = None,
- end_positions: Optional[torch.LongTensor] = None,
- output_attentions: Optional[bool] = None,
- output_hidden_states: Optional[bool] = None,
- return_dict: Optional[bool] = None,
- ) -> Union[tuple, QuestionAnsweringModelOutput]:
- r"""
- input_ids (`torch.LongTensor` of shape `(batch_size, input_ids_length)`):
- `input_ids_length` = `sequence_length` if `past_key_values` is `None` else `past_key_values.get_seq_length()`
- (`sequence_length` of input past key value states). Indices of input sequence tokens in the vocabulary.
- If `past_key_values` is used, only `input_ids` that do not have their past calculated should be passed as
- `input_ids`.
- Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
- [`PreTrainedTokenizer.__call__`] for details.
- [What are input IDs?](../glossary#input-ids)
- """
- return_dict = return_dict if return_dict is not None else self.config.use_return_dict
- outputs = self.transformer(
- input_ids,
- attention_mask=attention_mask,
- position_ids=position_ids,
- head_mask=head_mask,
- inputs_embeds=inputs_embeds,
- output_attentions=output_attentions,
- output_hidden_states=output_hidden_states,
- return_dict=return_dict,
- )
- sequence_output = outputs[0]
- logits = self.qa_outputs(sequence_output)
- start_logits, end_logits = logits.split(1, dim=-1)
- start_logits = start_logits.squeeze(-1).contiguous()
- end_logits = end_logits.squeeze(-1).contiguous()
- total_loss = None
- if start_positions is not None and end_positions is not None:
- # If we are on multi-GPU, split add a dimension
- if len(start_positions.size()) > 1:
- start_positions = start_positions.squeeze(-1)
- if len(end_positions.size()) > 1:
- end_positions = end_positions.squeeze(-1)
- # sometimes the start/end positions are outside our model inputs, we ignore these terms
- ignored_index = start_logits.size(1)
- start_positions = start_positions.clamp(0, ignored_index)
- end_positions = end_positions.clamp(0, ignored_index)
- loss_fct = CrossEntropyLoss(ignore_index=ignored_index)
- start_loss = loss_fct(start_logits, start_positions)
- end_loss = loss_fct(end_logits, end_positions)
- total_loss = (start_loss + end_loss) / 2
- if not return_dict:
- output = (start_logits, end_logits) + outputs[2:]
- return ((total_loss,) + output) if total_loss is not None else output
- return QuestionAnsweringModelOutput(
- loss=total_loss,
- start_logits=start_logits,
- end_logits=end_logits,
- hidden_states=outputs.hidden_states,
- attentions=outputs.attentions,
- )
- __all__ = [
- "BloomForCausalLM",
- "BloomModel",
- "BloomPreTrainedModel",
- "BloomForSequenceClassification",
- "BloomForTokenClassification",
- "BloomForQuestionAnswering",
- ]
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