team-10/venv/Lib/site-packages/transformers/models/lfm2/modeling_lfm2.py
2025-08-02 02:00:33 +02:00

756 lines
31 KiB
Python

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# This file was automatically generated from src/transformers/models/lfm2/modular_lfm2.py.
# Do NOT edit this file manually as any edits will be overwritten by the generation of
# the file from the modular. If any change should be done, please apply the change to the
# modular_lfm2.py file directly. One of our CI enforces this.
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# Copyright 2025 The HuggingFace 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.
from typing import Any, Callable, Optional, Union
import torch
import torch.nn.functional as F
from torch import nn
from ...cache_utils import Cache, DynamicCache
from ...generation import GenerationMixin
from ...integrations import use_kernel_forward_from_hub
from ...masking_utils import create_causal_mask
from ...modeling_layers import GradientCheckpointingLayer
from ...modeling_outputs import BaseModelOutputWithPast, CausalLMOutputWithPast
from ...modeling_rope_utils import ROPE_INIT_FUNCTIONS, dynamic_rope_update
from ...modeling_utils import ALL_ATTENTION_FUNCTIONS, PreTrainedModel
from ...processing_utils import Unpack
from ...utils import TransformersKwargs, auto_docstring, can_return_tuple
from ...utils.generic import check_model_inputs
from ...utils.import_utils import is_causal_conv1d_available
from .configuration_lfm2 import Lfm2Config
if is_causal_conv1d_available():
from causal_conv1d import causal_conv1d_fn, causal_conv1d_update
else:
causal_conv1d_fn, causal_conv1d_update = None, None
@use_kernel_forward_from_hub("RMSNorm")
class Lfm2RMSNorm(nn.Module):
def __init__(self, hidden_size, eps=1e-6):
"""
Lfm2RMSNorm is equivalent to T5LayerNorm
"""
super().__init__()
self.weight = nn.Parameter(torch.ones(hidden_size))
self.variance_epsilon = eps
def forward(self, hidden_states):
input_dtype = hidden_states.dtype
hidden_states = hidden_states.to(torch.float32)
variance = hidden_states.pow(2).mean(-1, keepdim=True)
hidden_states = hidden_states * torch.rsqrt(variance + self.variance_epsilon)
return self.weight * hidden_states.to(input_dtype)
def extra_repr(self):
return f"{tuple(self.weight.shape)}, eps={self.variance_epsilon}"
class Lfm2RotaryEmbedding(nn.Module):
def __init__(self, config: Lfm2Config, device=None):
super().__init__()
# BC: "rope_type" was originally "type"
if hasattr(config, "rope_scaling") and isinstance(config.rope_scaling, dict):
self.rope_type = config.rope_scaling.get("rope_type", config.rope_scaling.get("type"))
else:
self.rope_type = "default"
self.max_seq_len_cached = config.max_position_embeddings
self.original_max_seq_len = config.max_position_embeddings
self.config = config
self.rope_init_fn = ROPE_INIT_FUNCTIONS[self.rope_type]
inv_freq, self.attention_scaling = self.rope_init_fn(self.config, device)
self.register_buffer("inv_freq", inv_freq, persistent=False)
self.original_inv_freq = self.inv_freq
@torch.no_grad()
@dynamic_rope_update # power user: used with advanced RoPE types (e.g. dynamic rope)
def forward(self, x, position_ids):
inv_freq_expanded = self.inv_freq[None, :, None].float().expand(position_ids.shape[0], -1, 1).to(x.device)
position_ids_expanded = position_ids[:, None, :].float()
device_type = x.device.type if isinstance(x.device.type, str) and x.device.type != "mps" else "cpu"
with torch.autocast(device_type=device_type, enabled=False): # Force float32
freqs = (inv_freq_expanded.float() @ position_ids_expanded.float()).transpose(1, 2)
emb = torch.cat((freqs, freqs), dim=-1)
cos = emb.cos() * self.attention_scaling
sin = emb.sin() * self.attention_scaling
return cos.to(dtype=x.dtype), sin.to(dtype=x.dtype)
class Lfm2MLP(nn.Module):
def __init__(self, config: Lfm2Config):
super().__init__()
intermediate_size = config.intermediate_size
if config.block_auto_adjust_ff_dim:
intermediate_size = int(2 * intermediate_size / 3)
# custom dim factor multiplier
if config.block_ffn_dim_multiplier is not None:
intermediate_size = int(config.block_ffn_dim_multiplier * intermediate_size)
intermediate_size = config.block_multiple_of * (
(intermediate_size + config.block_multiple_of - 1) // config.block_multiple_of
)
self.w1 = nn.Linear(config.hidden_size, intermediate_size, bias=False)
self.w3 = nn.Linear(config.hidden_size, intermediate_size, bias=False)
self.w2 = nn.Linear(intermediate_size, config.hidden_size, bias=False)
def forward(self, x):
return self.w2(F.silu(self.w1(x)) * self.w3(x))
class Lfm2HybridConvCache(DynamicCache):
"""
Attention and conv cache for Lfm2.
It stores the Key and Value states as a list of tensors, one for each layer.
Attention layer cache shape: `[batch_size, num_heads, seq_len, head_dim]`.
Conv layer cache shape: `[batch_size, hidden_size, L_cache-1]`.
"""
# Override @property existing in Cache
max_batch_size = None
is_compileable = False
key_cache = None
value_cache = None
def __init__(
self,
config: Lfm2Config,
max_batch_size: int,
dtype: torch.dtype = torch.float32,
device: Union[torch.device, str, None] = None,
):
self.key_cache = []
self.value_cache = []
self.max_batch_size = max_batch_size
self.layer_types = config.layer_types
self.first_attention_layer = self.layer_types.index("full_attention")
self.conv_L_cache = config.conv_L_cache
self._dtype = dtype
self.conv_cache: list[torch.Tensor] = []
device = torch.device(device) if device is not None else None
for _ in range(config.num_hidden_layers):
conv_state = torch.zeros(
self.max_batch_size,
config.hidden_size,
self.conv_L_cache,
dtype=self._dtype,
device=device,
)
torch._dynamo.mark_static_address(conv_state)
self.conv_cache.append(conv_state)
def update(
self,
key_states: torch.Tensor,
value_states: torch.Tensor,
layer_idx: int,
cache_kwargs: Optional[dict[str, Any]] = None,
) -> tuple[torch.Tensor, torch.Tensor]:
"""
Updates the cache with the new `key_states` and `value_states` for the layer `layer_idx`.
Parameters:
key_states (`torch.Tensor`):
The new key states to cache.
value_states (`torch.Tensor`):
The new value states to cache.
layer_idx (`int`):
The index of the layer to cache the states for.
cache_kwargs (`Dict[str, Any]`, `optional`):
Additional arguments for the cache subclass. No additional arguments are used in `DynamicCache`.
Return:
A tuple containing the updated key and value states.
"""
# Update the cache
if key_states is not None:
if len(self.key_cache) <= layer_idx:
# There may be skipped layers, fill them with empty lists
for _ in range(len(self.key_cache), layer_idx):
self.key_cache.append(torch.tensor([]))
self.value_cache.append(torch.tensor([]))
self.key_cache.append(key_states)
self.value_cache.append(value_states)
elif (
not self.key_cache[layer_idx].numel() # prefers not t.numel() to len(t) == 0 to export the model
): # fills previously skipped layers; checking for tensor causes errors
self.key_cache[layer_idx] = key_states
self.value_cache[layer_idx] = value_states
else:
self.key_cache[layer_idx] = torch.cat([self.key_cache[layer_idx], key_states], dim=-2)
self.value_cache[layer_idx] = torch.cat([self.value_cache[layer_idx], value_states], dim=-2)
return self.key_cache[layer_idx], self.value_cache[layer_idx]
def reorder_cache(self, beam_idx: torch.LongTensor):
"""Reorders the cache for beam search, given the selected beam indices."""
for layer_idx in range(len(self.key_cache)):
device = self.key_cache[layer_idx].device
self.key_cache[layer_idx] = self.key_cache[layer_idx].index_select(0, beam_idx.to(device))
device = self.value_cache[layer_idx].device
self.value_cache[layer_idx] = self.value_cache[layer_idx].index_select(0, beam_idx.to(device))
device = self.conv_cache[layer_idx].device
self.conv_cache[layer_idx] = self.conv_cache[layer_idx].index_select(0, beam_idx.to(device))
def get_seq_length(self, layer_idx: Optional[int] = 0) -> int:
"""Returns the sequence length of the cached states. A layer index can be optionally passed."""
# take any layer that contains cache and not empty tensor
layer_idx = self.first_attention_layer if self.layer_types[layer_idx] != "full_attention" else layer_idx
if len(self.key_cache) <= layer_idx or self.key_cache[layer_idx].numel() == 0:
return 0
return self.key_cache[layer_idx].shape[-2]
def get_mask_sizes(self, cache_position: torch.Tensor, layer_idx: int) -> tuple[int, int]:
"""
Return a tuple (kv_length, kv_offset) corresponding to the length and offset that will be returned for
the given layer at `layer_idx`.
The masks are then prepared according to the given lengths (kv_length, kv_offset) and patterns (i.e. sliding_window, chunk_size),
for each layer.
"""
full_mask_kv_offset = 0
query_length = cache_position.shape[0]
past_seen_tokens = self.get_seq_length()
kv_length = query_length + past_seen_tokens
return kv_length, full_mask_kv_offset
def crop(self, max_length: int):
"""Crop the cache to the given length"""
if max_length < 0:
max_length = self.get_seq_length() - abs(max_length)
if self.get_seq_length() <= max_length:
return
for idx in range(len(self.key_cache)):
if self.key_cache[idx].numel():
self.key_cache[idx] = self.key_cache[idx][..., :max_length, :]
self.value_cache[idx] = self.value_cache[idx][..., :max_length, :]
def __getitem__(self, layer_idx: int) -> tuple[torch.Tensor, torch.Tensor]:
return self.key_cache[layer_idx], self.value_cache[layer_idx]
def to_legacy_cache(self) -> tuple[tuple[torch.Tensor], tuple[torch.Tensor]]:
raise NotImplementedError("Lfm2HybridConvCache does not have a legacy cache equivalent.")
@classmethod
def from_legacy_cache(cls, past_key_values: Optional[tuple[tuple[torch.FloatTensor]]] = None) -> "DynamicCache":
raise NotImplementedError("Lfm2HybridConvCache does not have a legacy cache equivalent.")
def reset(self):
for layer_idx in range(len(self.conv_cache)):
# In-place ops prevent breaking the static address
self.conv_cache[layer_idx].zero_()
def rotate_half(x):
"""Rotates half the hidden dims of the input."""
x1 = x[..., : x.shape[-1] // 2]
x2 = x[..., x.shape[-1] // 2 :]
return torch.cat((-x2, x1), dim=-1)
def apply_rotary_pos_emb(q, k, cos, sin, position_ids=None, unsqueeze_dim=1):
"""Applies Rotary Position Embedding to the query and key tensors.
Args:
q (`torch.Tensor`): The query tensor.
k (`torch.Tensor`): The key tensor.
cos (`torch.Tensor`): The cosine part of the rotary embedding.
sin (`torch.Tensor`): The sine part of the rotary embedding.
position_ids (`torch.Tensor`, *optional*):
Deprecated and unused.
unsqueeze_dim (`int`, *optional*, defaults to 1):
The 'unsqueeze_dim' argument specifies the dimension along which to unsqueeze cos[position_ids] and
sin[position_ids] so that they can be properly broadcasted to the dimensions of q and k. For example, note
that cos[position_ids] and sin[position_ids] have the shape [batch_size, seq_len, head_dim]. Then, if q and
k have the shape [batch_size, heads, seq_len, head_dim], then setting unsqueeze_dim=1 makes
cos[position_ids] and sin[position_ids] broadcastable to the shapes of q and k. Similarly, if q and k have
the shape [batch_size, seq_len, heads, head_dim], then set unsqueeze_dim=2.
Returns:
`tuple(torch.Tensor)` comprising of the query and key tensors rotated using the Rotary Position Embedding.
"""
cos = cos.unsqueeze(unsqueeze_dim)
sin = sin.unsqueeze(unsqueeze_dim)
q_embed = (q * cos) + (rotate_half(q) * sin)
k_embed = (k * cos) + (rotate_half(k) * sin)
return q_embed, k_embed
def repeat_kv(hidden_states: torch.Tensor, n_rep: int) -> torch.Tensor:
"""
This is the equivalent of torch.repeat_interleave(x, dim=1, repeats=n_rep). The hidden states go from (batch,
num_key_value_heads, seqlen, head_dim) to (batch, num_attention_heads, seqlen, head_dim)
"""
batch, num_key_value_heads, slen, head_dim = hidden_states.shape
if n_rep == 1:
return hidden_states
hidden_states = hidden_states[:, :, None, :, :].expand(batch, num_key_value_heads, n_rep, slen, head_dim)
return hidden_states.reshape(batch, num_key_value_heads * n_rep, slen, head_dim)
def eager_attention_forward(
module: nn.Module,
query: torch.Tensor,
key: torch.Tensor,
value: torch.Tensor,
attention_mask: Optional[torch.Tensor],
scaling: float,
dropout: float = 0.0,
**kwargs: Unpack[TransformersKwargs],
):
key_states = repeat_kv(key, module.num_key_value_groups)
value_states = repeat_kv(value, module.num_key_value_groups)
attn_weights = torch.matmul(query, key_states.transpose(2, 3)) * scaling
if attention_mask is not None:
causal_mask = attention_mask[:, :, :, : key_states.shape[-2]]
attn_weights = attn_weights + causal_mask
attn_weights = nn.functional.softmax(attn_weights, dim=-1, dtype=torch.float32).to(query.dtype)
attn_weights = nn.functional.dropout(attn_weights, p=dropout, training=module.training)
attn_output = torch.matmul(attn_weights, value_states)
attn_output = attn_output.transpose(1, 2).contiguous()
return attn_output, attn_weights
class Lfm2Attention(nn.Module):
"""Multi-headed attention from 'Attention Is All You Need' paper"""
def __init__(self, config: Lfm2Config, layer_idx: int):
super().__init__()
self.config = config
self.layer_idx = layer_idx
self.head_dim = getattr(config, "head_dim", config.hidden_size // config.num_attention_heads)
self.num_key_value_groups = config.num_attention_heads // config.num_key_value_heads
self.scaling = self.head_dim**-0.5
self.is_causal = True
self.q_proj = nn.Linear(config.hidden_size, config.num_attention_heads * self.head_dim, bias=False)
self.k_proj = nn.Linear(config.hidden_size, config.num_key_value_heads * self.head_dim, bias=False)
self.v_proj = nn.Linear(config.hidden_size, config.num_key_value_heads * self.head_dim, bias=False)
self.out_proj = nn.Linear(config.num_attention_heads * self.head_dim, config.hidden_size, bias=False)
self.q_layernorm = Lfm2RMSNorm(self.head_dim, eps=config.norm_eps)
self.k_layernorm = Lfm2RMSNorm(self.head_dim, eps=config.norm_eps)
def forward(
self,
hidden_states: torch.Tensor,
position_embeddings: tuple[torch.Tensor, torch.Tensor],
attention_mask: Optional[torch.Tensor],
past_key_value: Optional[Lfm2HybridConvCache] = None,
cache_position: Optional[torch.LongTensor] = None,
**kwargs,
) -> tuple[torch.Tensor, Optional[torch.Tensor], Optional[tuple[torch.Tensor]]]:
input_shape = hidden_states.shape[:-1]
hidden_shape = (*input_shape, -1, self.head_dim)
query_states = self.q_layernorm(self.q_proj(hidden_states).view(*hidden_shape)).transpose(1, 2)
key_states = self.k_layernorm(self.k_proj(hidden_states).view(*hidden_shape)).transpose(1, 2)
value_states = self.v_proj(hidden_states).view(*hidden_shape).transpose(1, 2)
cos, sin = position_embeddings
query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin)
if past_key_value is not None:
cache_kwargs = {"sin": sin, "cos": cos, "cache_position": cache_position}
key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx, cache_kwargs)
attention_interface: Callable = eager_attention_forward
if self.config._attn_implementation != "eager":
attention_interface = ALL_ATTENTION_FUNCTIONS[self.config._attn_implementation]
attn_output, attn_weights = attention_interface(
self,
query_states,
key_states,
value_states,
attention_mask,
dropout=0.0,
scaling=self.scaling,
**kwargs,
)
attn_output = attn_output.reshape(*input_shape, -1).contiguous()
output = self.out_proj(attn_output)
return output, attn_weights
def apply_mask_to_padding_states(hidden_states, attention_mask):
"""
Tunes out the hidden states for padding tokens, see https://github.com/state-spaces/mamba/issues/66
"""
if attention_mask is not None and attention_mask.shape[1] > 1 and attention_mask.shape[0] > 1:
dtype = hidden_states.dtype
hidden_states = (hidden_states * attention_mask[:, :, None]).to(dtype)
return hidden_states
kernel_modules = (causal_conv1d_fn, causal_conv1d_update)
is_fast_path_available = all(kernel_modules)
class Lfm2ShortConv(nn.Module):
def __init__(
self,
config: Lfm2Config,
layer_idx: int,
):
super().__init__()
self.config = config
self.layer_idx = layer_idx
self.L_cache = config.conv_L_cache
self.bias = config.conv_bias
self.conv = nn.Conv1d(
in_channels=config.hidden_size,
out_channels=config.hidden_size,
kernel_size=self.L_cache,
groups=config.hidden_size,
bias=self.bias,
padding=self.L_cache - 1,
)
self.in_proj = nn.Linear(config.hidden_size, 3 * config.hidden_size, bias=self.bias)
self.out_proj = nn.Linear(config.hidden_size, config.hidden_size, bias=self.bias)
def cuda_kernels_forward(
self,
x: torch.Tensor,
past_key_value: Optional[Lfm2HybridConvCache] = None,
cache_position: Optional[torch.LongTensor] = None,
attention_mask: Optional[torch.Tensor] = None,
):
x = apply_mask_to_padding_states(x, attention_mask)
BCx = self.in_proj(x).transpose(-1, -2)
B, C, x = BCx.chunk(3, dim=-2)
Bx = B * x
conv_weights = self.conv.weight.view(self.conv.weight.size(0), self.conv.weight.size(2))
if past_key_value is not None and cache_position[0] > 0:
conv_out = causal_conv1d_update(
Bx.squeeze(-1),
past_key_value.conv_cache[self.layer_idx],
conv_weights,
self.conv.bias,
None,
)
conv_out = conv_out.unsqueeze(-1)
else:
if past_key_value is not None:
conv_state = nn.functional.pad(Bx, (self.L_cache - Bx.shape[-1], 0))
past_key_value.conv_cache[self.layer_idx].copy_(conv_state)
conv_out = causal_conv1d_fn(Bx, conv_weights, self.conv.bias, activation=None)
y = C * conv_out
y = self.out_proj(y.transpose(-1, -2).contiguous())
return y
def slow_forward(
self,
x: torch.Tensor,
past_key_value: Optional[Lfm2HybridConvCache] = None,
cache_position: Optional[torch.LongTensor] = None,
attention_mask: Optional[torch.Tensor] = None,
):
seqlen = x.shape[1]
x = apply_mask_to_padding_states(x, attention_mask)
BCx = self.in_proj(x).transpose(-1, -2)
B, C, x = BCx.chunk(3, dim=-2)
Bx = B * x
if past_key_value is not None and cache_position[0] > 0:
conv_state = past_key_value.conv_cache[self.layer_idx]
cache_position = cache_position.clamp(0, self.L_cache - 1)
conv_state = conv_state.roll(shifts=-1, dims=-1)
conv_state[:, :, cache_position] = Bx.to(device=conv_state.device, dtype=conv_state.dtype)
past_key_value.conv_cache[self.layer_idx].copy_(conv_state)
conv_out = torch.sum(conv_state.to(Bx.device) * self.conv.weight[:, 0, :], dim=-1)
if self.bias:
conv_out += self.conv.bias
conv_out = conv_out.unsqueeze(-1)
else:
if past_key_value is not None:
conv_state = nn.functional.pad(Bx, (self.L_cache - Bx.shape[-1], 0))
past_key_value.conv_cache[self.layer_idx].copy_(conv_state)
conv_out = self.conv(Bx)[..., :seqlen]
y = C * conv_out
y = y.transpose(-1, -2).contiguous()
y = self.out_proj(y)
return y
def forward(
self,
hidden_states: torch.Tensor,
past_key_value: Optional[Lfm2HybridConvCache] = None,
cache_position: Optional[torch.LongTensor] = None,
attention_mask: Optional[torch.Tensor] = None,
):
if is_fast_path_available and "cuda" in hidden_states.device.type and not torch._dynamo.is_compiling():
return self.cuda_kernels_forward(hidden_states, past_key_value, cache_position, attention_mask)
return self.slow_forward(hidden_states, past_key_value, cache_position, attention_mask)
class Lfm2DecoderLayer(GradientCheckpointingLayer):
def __init__(self, config: Lfm2Config, layer_idx: int):
super().__init__()
self.is_attention_layer = config.layer_types[layer_idx] == "full_attention"
if self.is_attention_layer:
self.self_attn = Lfm2Attention(config, layer_idx)
else:
self.conv = Lfm2ShortConv(config, layer_idx)
self.feed_forward = Lfm2MLP(config)
self.operator_norm = Lfm2RMSNorm(config.hidden_size, eps=config.norm_eps)
self.ffn_norm = Lfm2RMSNorm(config.hidden_size, eps=config.norm_eps)
def forward(
self,
hidden_states: torch.Tensor,
position_embeddings: tuple[torch.Tensor, torch.Tensor],
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_value: Optional[tuple[torch.Tensor]] = None,
cache_position: Optional[torch.LongTensor] = None,
**kwargs,
) -> torch.Tensor:
residual = hidden_states
if self.is_attention_layer:
hidden_states, _ = self.self_attn(
hidden_states=self.operator_norm(hidden_states),
position_embeddings=position_embeddings,
attention_mask=attention_mask,
position_ids=position_ids,
past_key_value=past_key_value,
cache_position=cache_position,
**kwargs,
)
else:
hidden_states = self.conv(
hidden_states=self.operator_norm(hidden_states),
past_key_value=past_key_value,
cache_position=cache_position,
attention_mask=attention_mask,
)
hidden_states = hidden_states + residual
hidden_states = hidden_states + self.feed_forward(self.ffn_norm(hidden_states))
return hidden_states
@auto_docstring
class Lfm2PreTrainedModel(PreTrainedModel):
config: Lfm2Config
base_model_prefix = "model"
supports_gradient_checkpointing = True
_no_split_modules = ["Lfm2DecoderLayer"]
_skip_keys_device_placement = ["past_key_values"]
_supports_flash_attn = True
_supports_sdpa = True
_supports_flex_attn = True
_can_compile_fullgraph = False
_supports_attention_backend = True
_can_record_outputs = {
"hidden_states": Lfm2DecoderLayer,
"attentions": Lfm2Attention,
}
@auto_docstring
class Lfm2Model(Lfm2PreTrainedModel):
def __init__(self, config: Lfm2Config):
super().__init__(config)
self.padding_idx = config.pad_token_id
self.vocab_size = config.vocab_size
self.embed_tokens = nn.Embedding(config.vocab_size, config.hidden_size, self.padding_idx)
self.layers = nn.ModuleList(
[Lfm2DecoderLayer(config, layer_idx) for layer_idx in range(config.num_hidden_layers)]
)
self.rotary_emb = Lfm2RotaryEmbedding(config=config)
self.gradient_checkpointing = False
self.pos_emb = Lfm2RotaryEmbedding(config)
self.embedding_norm = Lfm2RMSNorm(config.hidden_size, eps=config.norm_eps)
# Initialize weights and apply final processing
self.post_init()
@check_model_inputs
@auto_docstring
def forward(
self,
input_ids: Optional[torch.LongTensor] = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_values: Optional[Lfm2HybridConvCache] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
use_cache: Optional[bool] = None,
cache_position: Optional[torch.LongTensor] = None,
**kwargs: Unpack[TransformersKwargs],
) -> BaseModelOutputWithPast:
if (input_ids is None) ^ (inputs_embeds is not None):
raise ValueError("You must specify exactly one of input_ids or inputs_embeds")
if inputs_embeds is None:
inputs_embeds = self.embed_tokens(input_ids)
if use_cache and past_key_values is None:
batch_size = inputs_embeds.shape[0]
past_key_values = Lfm2HybridConvCache(
config=self.config, max_batch_size=batch_size, dtype=self.dtype, device=self.device
)
if cache_position is None:
past_seen_tokens = past_key_values.get_seq_length() if past_key_values is not None else 0
cache_position = torch.arange(
past_seen_tokens, past_seen_tokens + inputs_embeds.shape[1], device=inputs_embeds.device
)
if position_ids is None:
position_ids = cache_position.unsqueeze(0)
causal_mask = create_causal_mask(
config=self.config,
input_embeds=inputs_embeds,
attention_mask=attention_mask,
cache_position=cache_position,
past_key_values=past_key_values,
position_ids=position_ids,
)
hidden_states = inputs_embeds
position_embeddings = self.pos_emb(hidden_states, position_ids)
# decoder layers
for decoder_layer in self.layers[: self.config.num_hidden_layers]:
hidden_states = decoder_layer(
hidden_states,
attention_mask=causal_mask,
position_ids=position_ids,
past_key_value=past_key_values,
cache_position=cache_position,
position_embeddings=position_embeddings,
**kwargs,
)
hidden_states = self.embedding_norm(hidden_states)
return BaseModelOutputWithPast(
last_hidden_state=hidden_states,
past_key_values=past_key_values,
)
@auto_docstring
class Lfm2ForCausalLM(Lfm2PreTrainedModel, GenerationMixin):
_tied_weights_keys = ["lm_head.weight"]
_tp_plan = {"lm_head": "colwise_rep"}
_pp_plan = {"lm_head": (["hidden_states"], ["logits"])}
def __init__(self, config):
super().__init__(config)
self.model = Lfm2Model(config)
self.vocab_size = config.vocab_size
self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False)
# Initialize weights and apply final processing
self.post_init()
def set_decoder(self, decoder):
self.model = decoder
def get_decoder(self):
return self.model
@can_return_tuple
@auto_docstring
def forward(
self,
input_ids: Optional[torch.LongTensor] = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_values: Optional[Cache] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
labels: Optional[torch.LongTensor] = None,
use_cache: Optional[bool] = None,
cache_position: Optional[torch.LongTensor] = None,
logits_to_keep: Union[int, torch.Tensor] = 0,
**kwargs: Unpack[TransformersKwargs],
) -> CausalLMOutputWithPast:
r"""
Example:
```python
>>> from transformers import AutoTokenizer, Lfm2ForCausalLM
>>> model = Lfm2ForCausalLM.from_pretrained("meta-lfm2/Lfm2-2-7b-hf")
>>> tokenizer = AutoTokenizer.from_pretrained("meta-lfm2/Lfm2-2-7b-hf")
>>> prompt = "Hey, are you conscious? Can you talk to me?"
>>> inputs = tokenizer(prompt, return_tensors="pt")
>>> # Generate
>>> generate_ids = model.generate(inputs.input_ids, max_length=30)
>>> tokenizer.batch_decode(generate_ids, skip_special_tokens=True, clean_up_tokenization_spaces=False)[0]
"Hey, are you conscious? Can you talk to me?\nI'm not conscious, but I can talk to you."
```"""
outputs: BaseModelOutputWithPast = self.model(
input_ids=input_ids,
attention_mask=attention_mask,
position_ids=position_ids,
past_key_values=past_key_values,
inputs_embeds=inputs_embeds,
use_cache=use_cache,
cache_position=cache_position,
**kwargs,
)
hidden_states = outputs.last_hidden_state
# Only compute necessary logits, and do not upcast them to float if we are not computing the loss
slice_indices = slice(-logits_to_keep, None) if isinstance(logits_to_keep, int) else logits_to_keep
logits = self.lm_head(hidden_states[:, slice_indices, :])
loss = None
if labels is not None:
loss = self.loss_function(logits=logits, labels=labels, vocab_size=self.config.vocab_size, **kwargs)
return CausalLMOutputWithPast(
loss=loss,
logits=logits,
past_key_values=outputs.past_key_values,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)
__all__ = ["Lfm2ForCausalLM", "Lfm2Model", "Lfm2PreTrainedModel"]