# 🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨 # 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. # 🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨 # 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"]