team-10/env/Lib/site-packages/transformers/models/modernbert/modular_modernbert.py
2025-08-02 07:34:44 +02:00

1532 lines
64 KiB
Python

# Copyright 2024 Answer.AI, LightOn, and contributors, and the HuggingFace Inc. team. 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.
import copy
import math
from contextlib import nullcontext
from typing import Literal, Optional, Union
import torch
import torch.nn.functional as F
import torch.utils.checkpoint
from torch import nn
from torch.nn import BCEWithLogitsLoss, CrossEntropyLoss, MSELoss
from ...activations import ACT2FN
from ...configuration_utils import PretrainedConfig
from ...modeling_attn_mask_utils import _prepare_4d_attention_mask
from ...modeling_layers import GradientCheckpointingLayer
from ...modeling_outputs import (
BaseModelOutput,
MaskedLMOutput,
QuestionAnsweringModelOutput,
SequenceClassifierOutput,
TokenClassifierOutput,
)
from ...modeling_utils import PreTrainedModel
from ...utils import auto_docstring, is_flash_attn_2_available, logging
from ...utils.import_utils import is_triton_available
from ..gemma.modeling_gemma import GemmaRotaryEmbedding, apply_rotary_pos_emb
if is_flash_attn_2_available():
from flash_attn.flash_attn_interface import flash_attn_varlen_qkvpacked_func
from flash_attn.layers.rotary import RotaryEmbedding
from flash_attn.ops.triton.rotary import apply_rotary
else:
RotaryEmbedding = object
logger = logging.get_logger(__name__)
class ModernBertConfig(PretrainedConfig):
r"""
This is the configuration class to store the configuration of a [`ModernBertModel`]. It is used to instantiate an ModernBert
model according to the specified arguments, defining the model architecture. Instantiating a configuration with the
defaults will yield a similar configuration to that of the ModernBERT-base.
e.g. [answerdotai/ModernBERT-base](https://huggingface.co/answerdotai/ModernBERT-base)
Configuration objects inherit from [`PretrainedConfig`] and can be used to control the model outputs. Read the
documentation from [`PretrainedConfig`] for more information.
Args:
vocab_size (`int`, *optional*, defaults to 50368):
Vocabulary size of the ModernBert model. Defines the number of different tokens that can be represented by the
`inputs_ids` passed when calling [`ModernBertModel`]
hidden_size (`int`, *optional*, defaults to 768):
Dimension of the hidden representations.
intermediate_size (`int`, *optional*, defaults to 1152):
Dimension of the MLP representations.
num_hidden_layers (`int`, *optional*, defaults to 22):
Number of hidden layers in the Transformer decoder.
num_attention_heads (`int`, *optional*, defaults to 12):
Number of attention heads for each attention layer in the Transformer decoder.
hidden_activation (`str` or `function`, *optional*, defaults to `"gelu"`):
The non-linear activation function (function or string) in the decoder. Will default to `"gelu"`
if not specified.
max_position_embeddings (`int`, *optional*, defaults to 8192):
The maximum sequence length that this model might ever be used with.
initializer_range (`float`, *optional*, defaults to 0.02):
The standard deviation of the truncated_normal_initializer for initializing all weight matrices.
initializer_cutoff_factor (`float`, *optional*, defaults to 2.0):
The cutoff factor for the truncated_normal_initializer for initializing all weight matrices.
norm_eps (`float`, *optional*, defaults to 1e-05):
The epsilon used by the rms normalization layers.
norm_bias (`bool`, *optional*, defaults to `False`):
Whether to use bias in the normalization layers.
pad_token_id (`int`, *optional*, defaults to 50283):
Padding token id.
eos_token_id (`int`, *optional*, defaults to 50282):
End of stream token id.
bos_token_id (`int`, *optional*, defaults to 50281):
Beginning of stream token id.
cls_token_id (`int`, *optional*, defaults to 50281):
Classification token id.
sep_token_id (`int`, *optional*, defaults to 50282):
Separation token id.
global_rope_theta (`float`, *optional*, defaults to 160000.0):
The base period of the global RoPE embeddings.
attention_bias (`bool`, *optional*, defaults to `False`):
Whether to use a bias in the query, key, value and output projection layers during self-attention.
attention_dropout (`float`, *optional*, defaults to 0.0):
The dropout ratio for the attention probabilities.
global_attn_every_n_layers (`int`, *optional*, defaults to 3):
The number of layers between global attention layers.
local_attention (`int`, *optional*, defaults to 128):
The window size for local attention.
local_rope_theta (`float`, *optional*, defaults to 10000.0):
The base period of the local RoPE embeddings.
embedding_dropout (`float`, *optional*, defaults to 0.0):
The dropout ratio for the embeddings.
mlp_bias (`bool`, *optional*, defaults to `False`):
Whether to use bias in the MLP layers.
mlp_dropout (`float`, *optional*, defaults to 0.0):
The dropout ratio for the MLP layers.
decoder_bias (`bool`, *optional*, defaults to `True`):
Whether to use bias in the decoder layers.
classifier_pooling (`str`, *optional*, defaults to `"cls"`):
The pooling method for the classifier. Should be either `"cls"` or `"mean"`. In local attention layers, the
CLS token doesn't attend to all tokens on long sequences.
classifier_dropout (`float`, *optional*, defaults to 0.0):
The dropout ratio for the classifier.
classifier_bias (`bool`, *optional*, defaults to `False`):
Whether to use bias in the classifier.
classifier_activation (`str`, *optional*, defaults to `"gelu"`):
The activation function for the classifier.
deterministic_flash_attn (`bool`, *optional*, defaults to `False`):
Whether to use deterministic flash attention. If `False`, inference will be faster but not deterministic.
sparse_prediction (`bool`, *optional*, defaults to `False`):
Whether to use sparse prediction for the masked language model instead of returning the full dense logits.
sparse_pred_ignore_index (`int`, *optional*, defaults to -100):
The index to ignore for the sparse prediction.
reference_compile (`bool`, *optional*):
Whether to compile the layers of the model which were compiled during pretraining. If `None`, then parts of
the model will be compiled if 1) `triton` is installed, 2) the model is not on MPS, 3) the model is not
shared between devices, and 4) the model is not resized after initialization. If `True`, then the model may
be faster in some scenarios.
repad_logits_with_grad (`bool`, *optional*, defaults to `False`):
When True, ModernBertForMaskedLM keeps track of the logits' gradient when repadding for output. This only
applies when using Flash Attention 2 with passed labels. Otherwise output logits always have a gradient.
Examples:
```python
>>> from transformers import ModernBertModel, ModernBertConfig
>>> # Initializing a ModernBert style configuration
>>> configuration = ModernBertConfig()
>>> # Initializing a model from the modernbert-base style configuration
>>> model = ModernBertModel(configuration)
>>> # Accessing the model configuration
>>> configuration = model.config
```"""
model_type = "modernbert"
attribute_map = {"rope_theta": "global_rope_theta"}
keys_to_ignore_at_inference = ["past_key_values"]
def __init__(
self,
vocab_size=50368,
hidden_size=768,
intermediate_size=1152,
num_hidden_layers=22,
num_attention_heads=12,
hidden_activation="gelu",
max_position_embeddings=8192,
initializer_range=0.02,
initializer_cutoff_factor=2.0,
norm_eps=1e-5,
norm_bias=False,
pad_token_id=50283,
eos_token_id=50282,
bos_token_id=50281,
cls_token_id=50281,
sep_token_id=50282,
global_rope_theta=160000.0,
attention_bias=False,
attention_dropout=0.0,
global_attn_every_n_layers=3,
local_attention=128,
local_rope_theta=10000.0,
embedding_dropout=0.0,
mlp_bias=False,
mlp_dropout=0.0,
decoder_bias=True,
classifier_pooling: Literal["cls", "mean"] = "cls",
classifier_dropout=0.0,
classifier_bias=False,
classifier_activation="gelu",
deterministic_flash_attn=False,
sparse_prediction=False,
sparse_pred_ignore_index=-100,
reference_compile=None,
repad_logits_with_grad=False,
**kwargs,
):
super().__init__(
pad_token_id=pad_token_id,
bos_token_id=bos_token_id,
eos_token_id=eos_token_id,
cls_token_id=cls_token_id,
sep_token_id=sep_token_id,
**kwargs,
)
self.vocab_size = vocab_size
self.max_position_embeddings = max_position_embeddings
self.hidden_size = hidden_size
self.intermediate_size = intermediate_size
self.num_hidden_layers = num_hidden_layers
self.num_attention_heads = num_attention_heads
self.initializer_range = initializer_range
self.initializer_cutoff_factor = initializer_cutoff_factor
self.norm_eps = norm_eps
self.norm_bias = norm_bias
self.global_rope_theta = global_rope_theta
self.attention_bias = attention_bias
self.attention_dropout = attention_dropout
self.hidden_activation = hidden_activation
self.global_attn_every_n_layers = global_attn_every_n_layers
self.local_attention = local_attention
self.local_rope_theta = local_rope_theta
self.embedding_dropout = embedding_dropout
self.mlp_bias = mlp_bias
self.mlp_dropout = mlp_dropout
self.decoder_bias = decoder_bias
self.classifier_pooling = classifier_pooling
self.classifier_dropout = classifier_dropout
self.classifier_bias = classifier_bias
self.classifier_activation = classifier_activation
self.deterministic_flash_attn = deterministic_flash_attn
self.sparse_prediction = sparse_prediction
self.sparse_pred_ignore_index = sparse_pred_ignore_index
self.reference_compile = reference_compile
self.repad_logits_with_grad = repad_logits_with_grad
if self.classifier_pooling not in ["cls", "mean"]:
raise ValueError(
f'Invalid value for `classifier_pooling`, should be either "cls" or "mean", but is {self.classifier_pooling}.'
)
def to_dict(self):
output = super().to_dict()
output.pop("reference_compile", None)
return output
def _unpad_modernbert_input(
inputs: torch.Tensor,
attention_mask: torch.Tensor,
position_ids: Optional[torch.Tensor] = None,
labels: Optional[torch.Tensor] = None,
) -> tuple[torch.Tensor, torch.Tensor, torch.Tensor, int, Optional[torch.Tensor], Optional[torch.Tensor]]:
"""
Remove padding from input sequences.
Args:
inputs: (batch, seqlen, ...) or (batch, seqlen)
attention_mask: (batch, seqlen), bool / int, 1 means valid and 0 means not valid.
position_ids: (batch, seqlen), int, position ids
labels: (batch, seqlen), int, labels
Returns:
unpadded_inputs: (total_nnz, ...), where total_nnz = number of tokens selected in attention_mask.
indices: (total_nnz)
cu_seqlens: (batch + 1), the cumulative sequence lengths
max_seqlen_in_batch: int
unpadded_position_ids: (total_nnz) or None
unpadded_labels: (total_nnz) or None
"""
seqlens_in_batch = attention_mask.sum(dim=-1, dtype=torch.int32)
indices = torch.nonzero(attention_mask.flatten(), as_tuple=False).flatten()
max_seqlen_in_batch = int(seqlens_in_batch.max().item())
cu_seqlens = torch.nn.functional.pad(torch.cumsum(seqlens_in_batch, dim=0, dtype=torch.int32), (1, 0))
if inputs.dim() == 2:
unpadded_inputs = inputs.flatten()[indices]
else:
batch, seqlen, *rest = inputs.shape
shape = batch * seqlen
unpadded_inputs = inputs.view(shape, *rest)[indices]
unpadded_position_ids = position_ids.flatten()[indices] if position_ids is not None else None
unpadded_labels = labels.flatten()[indices] if labels is not None else None
return unpadded_inputs, indices, cu_seqlens, max_seqlen_in_batch, unpadded_position_ids, unpadded_labels
def _pad_modernbert_output(
inputs: torch.Tensor,
indices: torch.Tensor,
batch: int,
seqlen: int,
) -> torch.Tensor:
"""
Add padding to sequences.
Args:
inputs: (total_nnz, ...) or (total_nnz,), where total_nnz = number of tokens selected in attention_mask.
indices: (total_nnz)
batch: int, batch size
seqlen: int, max sequence length
Returns:
padded_inputs: (batch, seqlen, ...) or (batch, seqlen)
"""
if inputs.dim() == 1:
output = torch.zeros(batch * seqlen, dtype=inputs.dtype, device=inputs.device)
output[indices] = inputs
padded_inputs = output.view(batch, seqlen)
else:
_, *rest = inputs.shape
output = torch.zeros(batch * seqlen, *rest, dtype=inputs.dtype, device=inputs.device)
output[indices] = inputs
padded_inputs = output.view(batch, seqlen, *rest)
return padded_inputs
class ApplyRotaryEmbUnpad(torch.autograd.Function):
@staticmethod
def forward(
ctx,
qkv,
cos,
sin,
cu_seqlens: Optional[torch.Tensor] = None,
max_seqlen: Optional[int] = None,
):
# (total_nnz, 3, nheads, headdim)
qkv = qkv.contiguous()
total_nnz, _three, _nheads, headdim = qkv.shape
# We need qkv to be contiguous so that when we reshape to combine (3, nheads) dimensions,
# we get the same tensor
# qk = rearrange(qkv[:, :2], "b_s t h d -> b_s (t h) d")
qk = qkv[:, :2].view(total_nnz, -1, headdim)
apply_rotary(
qk,
cos,
sin,
seqlen_offsets=0,
cu_seqlens=cu_seqlens,
max_seqlen=max_seqlen,
interleaved=False,
inplace=True,
)
ctx.save_for_backward(cos, sin, cu_seqlens)
ctx.max_seqlen = max_seqlen
return qkv
@staticmethod
def backward(ctx, do):
cos, sin, cu_seqlens = ctx.saved_tensors
do = do.contiguous()
total_nnz, _three, _nheads, headdim = do.shape
# We need dqkv to be contiguous so that when we reshape to combine (3, nheads) dimensions,
# we get the same tensor
dqk = do[:, :2].view(total_nnz, -1, headdim)
apply_rotary(
dqk,
cos,
sin,
seqlen_offsets=0,
cu_seqlens=cu_seqlens,
max_seqlen=ctx.max_seqlen,
interleaved=False,
inplace=True,
conjugate=True,
)
return do, None, None, None, None, None, None
def apply_rotary_unpadded(
qkv,
cos,
sin,
cu_seqlens: Optional[torch.Tensor] = None,
max_seqlen: Optional[int] = None,
):
"""
Arguments:
qkv: (total_nnz, 3, nheads, headdim) - input tensor for packed QKV.
cos, sin: (seqlen_rotary, rotary_dim / 2)
interleaved: if True, rotate pairs of even and odd dimensions (GPT-J style) instead
of 1st half and 2nd half (GPT-NeoX style).
inplace: if True, apply rotary embedding in-place.
seqlen_offsets: (batch_size,) or int. Each sequence in x is shifted by this amount.
Most commonly used in inference when we have KV cache.
cu_seqlens: (batch + 1,) or None
max_seqlen: int
Return:
out: (total_nnz, dim)
rotary_dim must be <= headdim
Apply rotary embedding to the first rotary_dim of x.
"""
return ApplyRotaryEmbUnpad.apply(qkv, cos, sin, cu_seqlens, max_seqlen)
class ModernBertUnpaddedRotaryEmbedding(RotaryEmbedding):
"""
The rotary position embeddings applied directly to unpadded sequences.
"""
def __init__(
self,
dim: int,
base: float = 10000.0,
max_seqlen: Optional[int] = None,
device: Optional[torch.device] = None,
dtype: Optional[torch.dtype] = None,
):
"""
max_seqlen: if max_seqlen, device, and dtype are provided, we precompute the cos_sin_cache
up to max_seqlen. If the max_seqlen, device, or dtype during training/inference differ,
the cos_sin_cache will be recomputed during the forward pass.
"""
super().__init__(dim=dim, base=base, device=device, interleaved=False)
self.max_seqlen = max_seqlen
if max_seqlen is not None and device is not None and dtype is not None:
self._update_cos_sin_cache(max_seqlen, device=device, dtype=dtype)
def forward(
self,
qkv: torch.Tensor,
cu_seqlens: torch.Tensor,
max_seqlen: Optional[int] = None,
) -> Union[torch.Tensor, tuple[torch.Tensor, torch.Tensor]]:
"""
Apply rotary embedding *inplace* to qkv.
qkv: (total_nnz, 3, nheads, headdim)
cu_seqlens: (batch + 1,) cumulative sequence lengths
max_seqlen: int max seq length in the batch
"""
if max_seqlen is not None:
self._update_cos_sin_cache(max_seqlen, device=qkv.device, dtype=qkv.dtype)
qkv = apply_rotary_unpadded(
qkv,
self._cos_cached,
self._sin_cached,
cu_seqlens=cu_seqlens,
max_seqlen=max_seqlen,
)
return qkv
def extra_repr(self) -> str:
return f"dim={self.dim}, base={self.base}, scale_base={self.scale_base}"
class ModernBertEmbeddings(nn.Module):
"""
Same as BertEmbeddings with a tiny tweak for positional embeddings indexing.
"""
def __init__(self, config: ModernBertConfig):
super().__init__()
self.config = config
self.tok_embeddings = nn.Embedding(config.vocab_size, config.hidden_size, padding_idx=config.pad_token_id)
self.norm = nn.LayerNorm(config.hidden_size, eps=config.norm_eps, bias=config.norm_bias)
self.drop = nn.Dropout(config.embedding_dropout)
@torch.compile(dynamic=True)
def compiled_embeddings(self, input_ids: torch.LongTensor) -> torch.Tensor:
return self.drop(self.norm(self.tok_embeddings(input_ids)))
def forward(
self, input_ids: Optional[torch.LongTensor] = None, inputs_embeds: Optional[torch.Tensor] = None
) -> torch.Tensor:
if inputs_embeds is not None:
hidden_states = self.drop(self.norm(inputs_embeds))
else:
hidden_states = (
self.compiled_embeddings(input_ids)
if self.config.reference_compile
else self.drop(self.norm(self.tok_embeddings(input_ids)))
)
return hidden_states
class ModernBertMLP(nn.Module):
"""Applies the GLU at the end of each ModernBERT layer.
Compared to the default BERT architecture, this block replaces :class:`~transformers.model.bert.modeling_bert.BertIntermediate`
and :class:`~transformers.model.bert.modeling_bert.SelfOutput` with a single module that has similar functionality.
"""
def __init__(self, config: ModernBertConfig):
super().__init__()
self.config = config
self.Wi = nn.Linear(config.hidden_size, int(config.intermediate_size) * 2, bias=config.mlp_bias)
self.act = ACT2FN[config.hidden_activation]
self.drop = nn.Dropout(config.mlp_dropout)
self.Wo = nn.Linear(config.intermediate_size, config.hidden_size, bias=config.mlp_bias)
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
input, gate = self.Wi(hidden_states).chunk(2, dim=-1)
return self.Wo(self.drop(self.act(input) * gate))
class ModernBertRotaryEmbedding(GemmaRotaryEmbedding):
pass
def eager_attention_forward(
module: "ModernBertAttention",
qkv: torch.Tensor,
attention_mask: torch.Tensor,
sliding_window_mask: torch.Tensor,
position_ids: Optional[torch.LongTensor],
local_attention: tuple[int, int],
bs: int,
dim: int,
output_attentions: Optional[bool] = False,
**_kwargs,
) -> Union[tuple[torch.Tensor, torch.Tensor], tuple[torch.Tensor]]:
# qkv: [batch_size, seqlen, 3, nheads, headdim]
cos, sin = module.rotary_emb(qkv, position_ids=position_ids)
query, key, value = qkv.transpose(3, 1).unbind(dim=2)
# query, key, value: [batch_size, heads, seq_len, head_dim]
query, key = apply_rotary_pos_emb(query, key, cos, sin)
scale = module.head_dim**-0.5
attn_weights = torch.matmul(query, key.transpose(2, 3)) * scale
if local_attention != (-1, -1):
attention_mask = sliding_window_mask
attn_weights = attn_weights + attention_mask
# upcast attention to fp32
attn_weights = nn.functional.softmax(attn_weights, dim=-1, dtype=torch.float32).to(query.dtype)
attn_weights = nn.functional.dropout(attn_weights, p=module.attention_dropout, training=module.training)
attn_output = torch.matmul(attn_weights, value)
attn_output = attn_output.transpose(1, 2).contiguous()
attn_output = attn_output.view(bs, -1, dim)
if output_attentions:
return (attn_output, attn_weights)
return (attn_output,)
def flash_attention_forward(
module: "ModernBertAttention",
qkv: torch.Tensor,
rotary_emb: ModernBertUnpaddedRotaryEmbedding,
cu_seqlens: torch.Tensor,
max_seqlen: int,
local_attention: tuple[int, int],
bs: int,
dim: int,
target_dtype: torch.dtype = torch.bfloat16,
**_kwargs,
) -> tuple[torch.Tensor]:
# (total_seqlen, 3, nheads, headdim)
qkv = rotary_emb(qkv, cu_seqlens=cu_seqlens, max_seqlen=max_seqlen)
convert_dtype = qkv.dtype not in (torch.float16, torch.bfloat16)
if convert_dtype:
# FA2 implementation only supports fp16 and bf16. If FA2 is supported,
# bfloat16 must be supported as of FA2 2.5.7. (Turing GPUs not supported)
orig_dtype = qkv.dtype
qkv = qkv.to(target_dtype)
attn = flash_attn_varlen_qkvpacked_func(
qkv,
cu_seqlens=cu_seqlens,
max_seqlen=max_seqlen,
dropout_p=module.attention_dropout if module.training else 0.0,
deterministic=module.deterministic_flash_attn,
window_size=local_attention,
)
attn = attn.to(orig_dtype) # type: ignore
else:
attn = flash_attn_varlen_qkvpacked_func(
qkv,
cu_seqlens=cu_seqlens,
max_seqlen=max_seqlen,
dropout_p=module.attention_dropout if module.training else 0.0,
deterministic=module.deterministic_flash_attn,
window_size=local_attention,
)
return (attn.view(bs, dim),)
def sdpa_attention_forward(
module: "ModernBertAttention",
qkv: torch.Tensor,
attention_mask: torch.Tensor,
sliding_window_mask: torch.Tensor,
position_ids: Optional[torch.LongTensor],
local_attention: tuple[int, int],
bs: int,
dim: int,
**_kwargs,
) -> tuple[torch.Tensor]:
# qkv: [batch_size, seqlen, 3, nheads, headdim]
cos, sin = module.rotary_emb(qkv, position_ids=position_ids)
query, key, value = qkv.transpose(3, 1).unbind(dim=2)
# query, key, value: [batch_size, heads, seq_len, head_dim]
query, key = apply_rotary_pos_emb(query, key, cos, sin)
if local_attention != (-1, -1):
attention_mask = sliding_window_mask
attn_output = (
F.scaled_dot_product_attention(
query,
key,
value,
dropout_p=module.attention_dropout if module.training else 0.0,
attn_mask=attention_mask,
)
.transpose(1, 2)
.contiguous()
)
attn_output = attn_output.view(bs, -1, dim)
return (attn_output,)
MODERNBERT_ATTENTION_FUNCTION = {
"flash_attention_2": flash_attention_forward,
"eager": eager_attention_forward,
"sdpa": sdpa_attention_forward,
}
class ModernBertAttention(nn.Module):
"""Performs multi-headed self attention on a batch of unpadded sequences.
If Flash Attention 2 is installed, this module uses Flash Attention to improve throughput.
If Flash Attention 2 is not installed, the implementation will use PyTorch's SDPA kernel,
which requires padding and unpadding inputs, adding some overhead.
See `forward` method for additional details.
"""
def __init__(self, config: ModernBertConfig, layer_id: Optional[int] = None):
super().__init__()
self.config = config
self.layer_id = layer_id
if config.hidden_size % config.num_attention_heads != 0:
raise ValueError(
f"The hidden size ({config.hidden_size}) is not a multiple of the number of attention heads ({config.num_attention_heads})"
)
self.attention_dropout = config.attention_dropout
self.deterministic_flash_attn = config.deterministic_flash_attn
self.num_heads = config.num_attention_heads
self.head_dim = config.hidden_size // config.num_attention_heads
self.all_head_size = self.head_dim * self.num_heads
self.Wqkv = nn.Linear(config.hidden_size, 3 * self.all_head_size, bias=config.attention_bias)
if layer_id % config.global_attn_every_n_layers != 0:
self.local_attention = (config.local_attention // 2, config.local_attention // 2)
rope_theta = config.local_rope_theta if config.local_rope_theta is not None else config.global_rope_theta
max_position_embeddings = config.local_attention
else:
self.local_attention = (-1, -1)
max_position_embeddings = config.max_position_embeddings
rope_theta = config.global_rope_theta
if config._attn_implementation == "flash_attention_2":
self.rotary_emb = ModernBertUnpaddedRotaryEmbedding(
dim=self.head_dim, max_seqlen=max_position_embeddings, base=rope_theta
)
else:
config_copy = copy.deepcopy(config)
config_copy.rope_theta = rope_theta
self.rotary_emb = ModernBertRotaryEmbedding(config=config_copy)
self.Wo = nn.Linear(config.hidden_size, config.hidden_size, bias=config.attention_bias)
self.out_drop = nn.Dropout(config.attention_dropout) if config.attention_dropout > 0.0 else nn.Identity()
self.pruned_heads = set()
def forward(
self,
hidden_states: torch.Tensor,
output_attentions: Optional[bool] = False,
**kwargs,
) -> torch.Tensor:
qkv = self.Wqkv(hidden_states)
bs = hidden_states.shape[0]
if self.config._attn_implementation == "flash_attention_2":
qkv = qkv.view(-1, 3, self.num_heads, self.head_dim)
else:
qkv = qkv.view(bs, -1, 3, self.num_heads, self.head_dim)
attn_outputs = MODERNBERT_ATTENTION_FUNCTION[self.config._attn_implementation](
self,
qkv=qkv,
rotary_emb=self.rotary_emb,
local_attention=self.local_attention,
bs=bs,
dim=self.all_head_size,
output_attentions=output_attentions,
**kwargs,
)
hidden_states = attn_outputs[0]
hidden_states = self.out_drop(self.Wo(hidden_states))
return (hidden_states,) + attn_outputs[1:] # add attentions if outputted
class ModernBertEncoderLayer(GradientCheckpointingLayer):
def __init__(self, config: ModernBertConfig, layer_id: Optional[int] = None):
super().__init__()
self.config = config
if layer_id == 0:
self.attn_norm = nn.Identity()
else:
self.attn_norm = nn.LayerNorm(config.hidden_size, eps=config.norm_eps, bias=config.norm_bias)
self.attn = ModernBertAttention(config=config, layer_id=layer_id)
self.mlp_norm = nn.LayerNorm(config.hidden_size, eps=config.norm_eps, bias=config.norm_bias)
self.mlp = ModernBertMLP(config)
@torch.compile(dynamic=True)
def compiled_mlp(self, hidden_states: torch.Tensor) -> torch.Tensor:
return self.mlp(self.mlp_norm(hidden_states))
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
sliding_window_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
cu_seqlens: Optional[torch.Tensor] = None,
max_seqlen: Optional[int] = None,
output_attentions: Optional[bool] = False,
) -> torch.Tensor:
attn_outputs = self.attn(
self.attn_norm(hidden_states),
attention_mask=attention_mask,
sliding_window_mask=sliding_window_mask,
position_ids=position_ids,
cu_seqlens=cu_seqlens,
max_seqlen=max_seqlen,
output_attentions=output_attentions,
)
hidden_states = hidden_states + attn_outputs[0]
mlp_output = (
self.compiled_mlp(hidden_states)
if self.config.reference_compile
else self.mlp(self.mlp_norm(hidden_states))
)
hidden_states = hidden_states + mlp_output
return (hidden_states,) + attn_outputs[1:] # add attentions if outputted
@auto_docstring
class ModernBertPreTrainedModel(PreTrainedModel):
config: ModernBertConfig
base_model_prefix = "model"
supports_gradient_checkpointing = True
_no_split_modules = ["ModernBertEmbeddings", "ModernBertEncoderLayer"]
_supports_flash_attn = True
_supports_sdpa = True
_supports_flex_attn = False
def _init_weights(self, module: nn.Module):
cutoff_factor = self.config.initializer_cutoff_factor
if cutoff_factor is None:
cutoff_factor = 3
def init_weight(module: nn.Module, std: float):
nn.init.trunc_normal_(
module.weight,
mean=0.0,
std=std,
a=-cutoff_factor * std,
b=cutoff_factor * std,
)
if isinstance(module, nn.Linear):
if module.bias is not None:
nn.init.zeros_(module.bias)
stds = {
"in": self.config.initializer_range,
"out": self.config.initializer_range / math.sqrt(2.0 * self.config.num_hidden_layers),
"embedding": self.config.initializer_range,
"final_out": self.config.hidden_size**-0.5,
}
if isinstance(module, ModernBertEmbeddings):
init_weight(module.tok_embeddings, stds["embedding"])
elif isinstance(module, ModernBertMLP):
init_weight(module.Wi, stds["in"])
init_weight(module.Wo, stds["out"])
elif isinstance(module, ModernBertAttention):
init_weight(module.Wqkv, stds["in"])
init_weight(module.Wo, stds["out"])
elif isinstance(module, ModernBertPredictionHead):
init_weight(module.dense, stds["out"])
elif isinstance(module, ModernBertForMaskedLM):
init_weight(module.decoder, stds["out"])
elif isinstance(
module,
(ModernBertForSequenceClassification, ModernBertForTokenClassification, ModernBertForQuestionAnswering),
):
init_weight(module.classifier, stds["final_out"])
elif isinstance(module, nn.LayerNorm):
module.weight.data.fill_(1.0)
if module.bias is not None:
module.bias.data.zero_()
def _check_and_adjust_attn_implementation(
self, attn_implementation: Optional[str], is_init_check: bool = False
) -> str:
"""
Checks and dispatches to hhe requested attention implementation.
"""
# If the user didn't specify anything, try to use flash_attention_2 if available.
# Otherwise we fall back to the default SDPA -> Eager from the super() method.
# ModernBert's FA2 implementation correctly handles non-fp16/bf16 dtypes, we don't
# need the FA2 warning for non-fp16/bf16 dtypes so we set fp16 for the FA2 check.
try:
attn_implementation = (
"flash_attention_2"
if attn_implementation is None and self._flash_attn_2_can_dispatch()
else attn_implementation
)
except (ValueError, ImportError):
pass
return super()._check_and_adjust_attn_implementation(
attn_implementation=attn_implementation, is_init_check=is_init_check
)
def _maybe_set_compile(self):
if self.config.reference_compile is False:
return
if hasattr(self, "hf_device_map") and len(self.hf_device_map) > 1:
if self.config.reference_compile:
logger.warning_once(
"If `accelerate` split the model across devices, `torch.compile` will not work. "
"Falling back to non-compiled mode."
)
self.config.reference_compile = False
if self.device.type == "mps":
if self.config.reference_compile:
logger.warning_once(
"Compiling the model with `torch.compile` and using a `torch.mps` device is not supported. "
"Falling back to non-compiled mode."
)
self.config.reference_compile = False
if self.device.type == "cpu":
if self.config.reference_compile:
logger.warning_once(
"Compiling the model with `torch.compile` and using a `torch.cpu` device is not supported. "
"Falling back to non-compiled mode."
)
self.config.reference_compile = False
if self.config.reference_compile is None:
self.config.reference_compile = is_triton_available()
def resize_token_embeddings(self, *args, **kwargs):
model_embeds = super().resize_token_embeddings(*args, **kwargs)
if self.config.reference_compile in {True, None}:
if self.config.reference_compile:
logger.warning_once(
"Resizing token embeddings with `torch.compile` is not supported. Falling back to non-compiled mode."
)
self.config.reference_compile = False
return model_embeds
@auto_docstring
class ModernBertModel(ModernBertPreTrainedModel):
def __init__(self, config: ModernBertConfig):
super().__init__(config)
self.config = config
self.embeddings = ModernBertEmbeddings(config)
self.layers = nn.ModuleList(
[ModernBertEncoderLayer(config, layer_id) for layer_id in range(config.num_hidden_layers)]
)
self.final_norm = nn.LayerNorm(config.hidden_size, eps=config.norm_eps, bias=config.norm_bias)
self.gradient_checkpointing = False
self.post_init()
def get_input_embeddings(self):
return self.embeddings.tok_embeddings
def set_input_embeddings(self, value):
self.embeddings.tok_embeddings = value
@auto_docstring
def forward(
self,
input_ids: Optional[torch.LongTensor] = None,
attention_mask: Optional[torch.Tensor] = None,
sliding_window_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
inputs_embeds: Optional[torch.Tensor] = None,
indices: Optional[torch.Tensor] = None,
cu_seqlens: Optional[torch.Tensor] = None,
max_seqlen: Optional[int] = None,
batch_size: Optional[int] = None,
seq_len: Optional[int] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[tuple[torch.Tensor, ...], BaseModelOutput]:
r"""
sliding_window_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
Mask to avoid performing attention on padding or far-away tokens. In ModernBert, only every few layers
perform global attention, while the rest perform local attention. This mask is used to avoid attending to
far-away tokens in the local attention layers when not using Flash Attention.
indices (`torch.Tensor` of shape `(total_unpadded_tokens,)`, *optional*):
Indices of the non-padding tokens in the input sequence. Used for unpadding the output.
cu_seqlens (`torch.Tensor` of shape `(batch + 1,)`, *optional*):
Cumulative sequence lengths of the input sequences. Used to index the unpadded tensors.
max_seqlen (`int`, *optional*):
Maximum sequence length in the batch excluding padding tokens. Used to unpad input_ids and pad output tensors.
batch_size (`int`, *optional*):
Batch size of the input sequences. Used to pad the output tensors.
seq_len (`int`, *optional*):
Sequence length of the input sequences including padding tokens. Used to pad the output tensors.
"""
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
if (input_ids is None) ^ (inputs_embeds is not None):
raise ValueError("You must specify exactly one of input_ids or inputs_embeds")
all_hidden_states = () if output_hidden_states else None
all_self_attentions = () if output_attentions else None
self._maybe_set_compile()
if input_ids is not None:
self.warn_if_padding_and_no_attention_mask(input_ids, attention_mask)
if batch_size is None and seq_len is None:
if inputs_embeds is not None:
batch_size, seq_len = inputs_embeds.shape[:2]
else:
batch_size, seq_len = input_ids.shape[:2]
device = input_ids.device if input_ids is not None else inputs_embeds.device
if attention_mask is None:
attention_mask = torch.ones((batch_size, seq_len), device=device, dtype=torch.bool)
repad = False
if self.config._attn_implementation == "flash_attention_2":
if indices is None and cu_seqlens is None and max_seqlen is None:
repad = True
if inputs_embeds is None:
with torch.no_grad():
input_ids, indices, cu_seqlens, max_seqlen, *_ = _unpad_modernbert_input(
inputs=input_ids, attention_mask=attention_mask
)
else:
inputs_embeds, indices, cu_seqlens, max_seqlen, *_ = _unpad_modernbert_input(
inputs=inputs_embeds, attention_mask=attention_mask
)
else:
if position_ids is None:
position_ids = torch.arange(seq_len, device=device).unsqueeze(0)
attention_mask, sliding_window_mask = self._update_attention_mask(
attention_mask, output_attentions=output_attentions
)
hidden_states = self.embeddings(input_ids=input_ids, inputs_embeds=inputs_embeds)
for encoder_layer in self.layers:
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
layer_outputs = encoder_layer(
hidden_states,
attention_mask=attention_mask,
sliding_window_mask=sliding_window_mask,
position_ids=position_ids,
cu_seqlens=cu_seqlens,
max_seqlen=max_seqlen,
output_attentions=output_attentions,
)
hidden_states = layer_outputs[0]
if output_attentions and len(layer_outputs) > 1:
all_self_attentions = all_self_attentions + (layer_outputs[1],)
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
hidden_states = self.final_norm(hidden_states)
if repad:
hidden_states = _pad_modernbert_output(
inputs=hidden_states, indices=indices, batch=batch_size, seqlen=seq_len
)
if all_hidden_states is not None:
all_hidden_states = tuple(
_pad_modernbert_output(inputs=hs, indices=indices, batch=batch_size, seqlen=seq_len)
for hs in all_hidden_states
)
if not return_dict:
return tuple(v for v in [hidden_states, all_hidden_states, all_self_attentions] if v is not None)
return BaseModelOutput(
last_hidden_state=hidden_states,
hidden_states=all_hidden_states,
attentions=all_self_attentions,
)
def _update_attention_mask(self, attention_mask: torch.Tensor, output_attentions: bool) -> torch.Tensor:
if output_attentions:
if self.config._attn_implementation == "sdpa":
logger.warning_once(
"Outputting attentions is only supported with the 'eager' attention implementation, "
'not with "sdpa". Falling back to `attn_implementation="eager"`.'
)
self.config._attn_implementation = "eager"
elif self.config._attn_implementation != "eager":
logger.warning_once(
"Outputting attentions is only supported with the eager attention implementation, "
f'not with {self.config._attn_implementation}. Consider setting `attn_implementation="eager"`.'
" Setting `output_attentions=False`."
)
global_attention_mask = _prepare_4d_attention_mask(attention_mask, self.dtype)
# Create position indices
rows = torch.arange(global_attention_mask.shape[2]).unsqueeze(0)
# Calculate distance between positions
distance = torch.abs(rows - rows.T)
# Create sliding window mask (1 for positions within window, 0 outside)
window_mask = (
(distance <= self.config.local_attention // 2).unsqueeze(0).unsqueeze(0).to(attention_mask.device)
)
# Combine with existing mask
sliding_window_mask = global_attention_mask.masked_fill(window_mask.logical_not(), torch.finfo(self.dtype).min)
return global_attention_mask, sliding_window_mask
class ModernBertPredictionHead(nn.Module):
def __init__(self, config: ModernBertConfig):
super().__init__()
self.config = config
self.dense = nn.Linear(config.hidden_size, config.hidden_size, config.classifier_bias)
self.act = ACT2FN[config.classifier_activation]
self.norm = nn.LayerNorm(config.hidden_size, eps=config.norm_eps, bias=config.norm_bias)
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
return self.norm(self.act(self.dense(hidden_states)))
@auto_docstring(
custom_intro="""
The ModernBert Model with a decoder head on top that is used for masked language modeling.
"""
)
class ModernBertForMaskedLM(ModernBertPreTrainedModel):
_tied_weights_keys = ["decoder.weight"]
def __init__(self, config: ModernBertConfig):
super().__init__(config)
self.config = config
self.model = ModernBertModel(config)
self.head = ModernBertPredictionHead(config)
self.decoder = nn.Linear(config.hidden_size, config.vocab_size, bias=config.decoder_bias)
self.sparse_prediction = self.config.sparse_prediction
self.sparse_pred_ignore_index = self.config.sparse_pred_ignore_index
# Initialize weights and apply final processing
self.post_init()
def get_output_embeddings(self):
return self.decoder
def set_output_embeddings(self, new_embeddings: nn.Linear):
self.decoder = new_embeddings
@torch.compile(dynamic=True)
def compiled_head(self, output: torch.Tensor) -> torch.Tensor:
return self.decoder(self.head(output))
@auto_docstring
def forward(
self,
input_ids: Optional[torch.LongTensor] = None,
attention_mask: Optional[torch.Tensor] = None,
sliding_window_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.Tensor] = None,
inputs_embeds: Optional[torch.Tensor] = None,
labels: Optional[torch.Tensor] = None,
indices: Optional[torch.Tensor] = None,
cu_seqlens: Optional[torch.Tensor] = None,
max_seqlen: Optional[int] = None,
batch_size: Optional[int] = None,
seq_len: Optional[int] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
**kwargs,
) -> Union[tuple[torch.Tensor], MaskedLMOutput]:
r"""
sliding_window_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
Mask to avoid performing attention on padding or far-away tokens. In ModernBert, only every few layers
perform global attention, while the rest perform local attention. This mask is used to avoid attending to
far-away tokens in the local attention layers when not using Flash Attention.
indices (`torch.Tensor` of shape `(total_unpadded_tokens,)`, *optional*):
Indices of the non-padding tokens in the input sequence. Used for unpadding the output.
cu_seqlens (`torch.Tensor` of shape `(batch + 1,)`, *optional*):
Cumulative sequence lengths of the input sequences. Used to index the unpadded tensors.
max_seqlen (`int`, *optional*):
Maximum sequence length in the batch excluding padding tokens. Used to unpad input_ids and pad output tensors.
batch_size (`int`, *optional*):
Batch size of the input sequences. Used to pad the output tensors.
seq_len (`int`, *optional*):
Sequence length of the input sequences including padding tokens. Used to pad the output tensors.
"""
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
self._maybe_set_compile()
if self.config._attn_implementation == "flash_attention_2":
if indices is None and cu_seqlens is None and max_seqlen is None:
if batch_size is None and seq_len is None:
if inputs_embeds is not None:
batch_size, seq_len = inputs_embeds.shape[:2]
else:
batch_size, seq_len = input_ids.shape[:2]
device = input_ids.device if input_ids is not None else inputs_embeds.device
if attention_mask is None:
attention_mask = torch.ones((batch_size, seq_len), device=device, dtype=torch.bool)
if inputs_embeds is None:
with torch.no_grad():
input_ids, indices, cu_seqlens, max_seqlen, position_ids, labels = _unpad_modernbert_input(
inputs=input_ids, attention_mask=attention_mask, position_ids=position_ids, labels=labels
)
else:
inputs_embeds, indices, cu_seqlens, max_seqlen, position_ids, labels = _unpad_modernbert_input(
inputs=inputs_embeds, attention_mask=attention_mask, position_ids=position_ids, labels=labels
)
outputs = self.model(
input_ids=input_ids,
attention_mask=attention_mask,
sliding_window_mask=sliding_window_mask,
position_ids=position_ids,
inputs_embeds=inputs_embeds,
indices=indices,
cu_seqlens=cu_seqlens,
max_seqlen=max_seqlen,
batch_size=batch_size,
seq_len=seq_len,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
last_hidden_state = outputs[0]
if self.sparse_prediction and labels is not None:
# flatten labels and output first
labels = labels.view(-1)
last_hidden_state = last_hidden_state.view(labels.shape[0], -1)
# then filter out the non-masked tokens
mask_tokens = labels != self.sparse_pred_ignore_index
last_hidden_state = last_hidden_state[mask_tokens]
labels = labels[mask_tokens]
logits = (
self.compiled_head(last_hidden_state)
if self.config.reference_compile
else self.decoder(self.head(last_hidden_state))
)
loss = None
if labels is not None:
loss = self.loss_function(logits, labels, vocab_size=self.config.vocab_size, **kwargs)
if self.config._attn_implementation == "flash_attention_2":
with nullcontext() if self.config.repad_logits_with_grad or labels is None else torch.no_grad():
logits = _pad_modernbert_output(inputs=logits, indices=indices, batch=batch_size, seqlen=seq_len)
if not return_dict:
output = (logits,)
return ((loss,) + output) if loss is not None else output
return MaskedLMOutput(
loss=loss,
logits=logits,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)
@auto_docstring(
custom_intro="""
The ModernBert Model with a sequence classification head on top that performs pooling.
"""
)
class ModernBertForSequenceClassification(ModernBertPreTrainedModel):
def __init__(self, config: ModernBertConfig):
super().__init__(config)
self.num_labels = config.num_labels
self.config = config
self.model = ModernBertModel(config)
self.head = ModernBertPredictionHead(config)
self.drop = torch.nn.Dropout(config.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,
attention_mask: Optional[torch.Tensor] = None,
sliding_window_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.Tensor] = None,
inputs_embeds: Optional[torch.Tensor] = None,
labels: Optional[torch.Tensor] = None,
indices: Optional[torch.Tensor] = None,
cu_seqlens: Optional[torch.Tensor] = None,
max_seqlen: Optional[int] = None,
batch_size: Optional[int] = None,
seq_len: Optional[int] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
**kwargs,
) -> Union[tuple[torch.Tensor], SequenceClassifierOutput]:
r"""
sliding_window_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
Mask to avoid performing attention on padding or far-away tokens. In ModernBert, only every few layers
perform global attention, while the rest perform local attention. This mask is used to avoid attending to
far-away tokens in the local attention layers when not using Flash Attention.
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).
indices (`torch.Tensor` of shape `(total_unpadded_tokens,)`, *optional*):
Indices of the non-padding tokens in the input sequence. Used for unpadding the output.
cu_seqlens (`torch.Tensor` of shape `(batch + 1,)`, *optional*):
Cumulative sequence lengths of the input sequences. Used to index the unpadded tensors.
max_seqlen (`int`, *optional*):
Maximum sequence length in the batch excluding padding tokens. Used to unpad input_ids and pad output tensors.
batch_size (`int`, *optional*):
Batch size of the input sequences. Used to pad the output tensors.
seq_len (`int`, *optional*):
Sequence length of the input sequences including padding tokens. Used to pad the output tensors.
"""
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
self._maybe_set_compile()
outputs = self.model(
input_ids=input_ids,
attention_mask=attention_mask,
sliding_window_mask=sliding_window_mask,
position_ids=position_ids,
inputs_embeds=inputs_embeds,
indices=indices,
cu_seqlens=cu_seqlens,
max_seqlen=max_seqlen,
batch_size=batch_size,
seq_len=seq_len,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
last_hidden_state = outputs[0]
if self.config.classifier_pooling == "cls":
last_hidden_state = last_hidden_state[:, 0]
elif self.config.classifier_pooling == "mean":
last_hidden_state = (last_hidden_state * attention_mask.unsqueeze(-1)).sum(dim=1) / attention_mask.sum(
dim=1, keepdim=True
)
pooled_output = self.head(last_hidden_state)
pooled_output = self.drop(pooled_output)
logits = self.classifier(pooled_output)
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(logits.squeeze(), labels.squeeze())
else:
loss = loss_fct(logits, labels)
elif self.config.problem_type == "single_label_classification":
loss_fct = CrossEntropyLoss()
loss = loss_fct(logits.view(-1, self.num_labels), labels.view(-1))
elif self.config.problem_type == "multi_label_classification":
loss_fct = BCEWithLogitsLoss()
loss = loss_fct(logits, labels)
if not return_dict:
output = (logits,)
return ((loss,) + output) if loss is not None else output
return SequenceClassifierOutput(
loss=loss,
logits=logits,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)
@auto_docstring(
custom_intro="""
The ModernBert Model with a token classification head on top, e.g. for Named Entity Recognition (NER) tasks.
"""
)
class ModernBertForTokenClassification(ModernBertPreTrainedModel):
def __init__(self, config: ModernBertConfig):
super().__init__(config)
self.num_labels = config.num_labels
self.model = ModernBertModel(config)
self.head = ModernBertPredictionHead(config)
self.drop = torch.nn.Dropout(config.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,
attention_mask: Optional[torch.Tensor] = None,
sliding_window_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.Tensor] = None,
inputs_embeds: Optional[torch.Tensor] = None,
labels: Optional[torch.Tensor] = None,
indices: Optional[torch.Tensor] = None,
cu_seqlens: Optional[torch.Tensor] = None,
max_seqlen: Optional[int] = None,
batch_size: Optional[int] = None,
seq_len: Optional[int] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[tuple[torch.Tensor], TokenClassifierOutput]:
r"""
sliding_window_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
Mask to avoid performing attention on padding or far-away tokens. In ModernBert, only every few layers
perform global attention, while the rest perform local attention. This mask is used to avoid attending to
far-away tokens in the local attention layers when not using Flash Attention.
labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
Labels for computing the token classification loss. Indices should be in `[0, ..., config.num_labels - 1]`.
indices (`torch.Tensor` of shape `(total_unpadded_tokens,)`, *optional*):
Indices of the non-padding tokens in the input sequence. Used for unpadding the output.
cu_seqlens (`torch.Tensor` of shape `(batch + 1,)`, *optional*):
Cumulative sequence lengths of the input sequences. Used to index the unpadded tensors.
max_seqlen (`int`, *optional*):
Maximum sequence length in the batch excluding padding tokens. Used to unpad input_ids and pad output tensors.
batch_size (`int`, *optional*):
Batch size of the input sequences. Used to pad the output tensors.
seq_len (`int`, *optional*):
Sequence length of the input sequences including padding tokens. Used to pad the output tensors.
"""
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
self._maybe_set_compile()
outputs = self.model(
input_ids=input_ids,
attention_mask=attention_mask,
sliding_window_mask=sliding_window_mask,
position_ids=position_ids,
inputs_embeds=inputs_embeds,
indices=indices,
cu_seqlens=cu_seqlens,
max_seqlen=max_seqlen,
batch_size=batch_size,
seq_len=seq_len,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
last_hidden_state = outputs[0]
last_hidden_state = self.head(last_hidden_state)
last_hidden_state = self.drop(last_hidden_state)
logits = self.classifier(last_hidden_state)
loss = None
if labels is not None:
loss_fct = CrossEntropyLoss()
loss = loss_fct(logits.view(-1, self.num_labels), labels.view(-1))
if not return_dict:
output = (logits,) + outputs[1:]
return ((loss,) + output) if loss is not None else output
return TokenClassifierOutput(
loss=loss,
logits=logits,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)
@auto_docstring
class ModernBertForQuestionAnswering(ModernBertPreTrainedModel):
def __init__(self, config: ModernBertConfig):
super().__init__(config)
self.num_labels = config.num_labels
self.model = ModernBertModel(config)
self.head = ModernBertPredictionHead(config)
self.drop = torch.nn.Dropout(config.classifier_dropout)
self.classifier = nn.Linear(config.hidden_size, config.num_labels)
self.post_init()
@auto_docstring
def forward(
self,
input_ids: Optional[torch.Tensor],
attention_mask: Optional[torch.Tensor] = None,
sliding_window_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.Tensor] = None,
start_positions: Optional[torch.Tensor] = None,
end_positions: Optional[torch.Tensor] = None,
indices: Optional[torch.Tensor] = None,
cu_seqlens: Optional[torch.Tensor] = None,
max_seqlen: Optional[int] = None,
batch_size: Optional[int] = None,
seq_len: Optional[int] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
**kwargs,
) -> Union[tuple[torch.Tensor], QuestionAnsweringModelOutput]:
r"""
sliding_window_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
Mask to avoid performing attention on padding or far-away tokens. In ModernBert, only every few layers
perform global attention, while the rest perform local attention. This mask is used to avoid attending to
far-away tokens in the local attention layers when not using Flash Attention.
indices (`torch.Tensor` of shape `(total_unpadded_tokens,)`, *optional*):
Indices of the non-padding tokens in the input sequence. Used for unpadding the output.
cu_seqlens (`torch.Tensor` of shape `(batch + 1,)`, *optional*):
Cumulative sequence lengths of the input sequences. Used to index the unpadded tensors.
max_seqlen (`int`, *optional*):
Maximum sequence length in the batch excluding padding tokens. Used to unpad input_ids and pad output tensors.
batch_size (`int`, *optional*):
Batch size of the input sequences. Used to pad the output tensors.
seq_len (`int`, *optional*):
Sequence length of the input sequences including padding tokens. Used to pad the output tensors.
"""
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
self._maybe_set_compile()
outputs = self.model(
input_ids,
attention_mask=attention_mask,
sliding_window_mask=sliding_window_mask,
position_ids=position_ids,
indices=indices,
cu_seqlens=cu_seqlens,
max_seqlen=max_seqlen,
batch_size=batch_size,
seq_len=seq_len,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
last_hidden_state = outputs[0]
last_hidden_state = self.head(last_hidden_state)
last_hidden_state = self.drop(last_hidden_state)
logits = self.classifier(last_hidden_state)
start_logits, end_logits = logits.split(1, dim=-1)
start_logits = start_logits.squeeze(-1).contiguous()
end_logits = end_logits.squeeze(-1).contiguous()
loss = None
if start_positions is not None and end_positions is not None:
loss = self.loss_function(start_logits, end_logits, start_positions, end_positions, **kwargs)
if not return_dict:
output = (start_logits, end_logits) + outputs[1:]
return ((loss,) + output) if loss is not None else output
return QuestionAnsweringModelOutput(
loss=loss,
start_logits=start_logits,
end_logits=end_logits,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)
__all__ = [
"ModernBertConfig",
"ModernBertModel",
"ModernBertPreTrainedModel",
"ModernBertForMaskedLM",
"ModernBertForSequenceClassification",
"ModernBertForTokenClassification",
"ModernBertForQuestionAnswering",
]