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- # coding=utf-8
- # Copyright 2024 Microsoft 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.
- """PyTorch Phimoe model."""
- import math
- from typing import Optional, Union
- import torch
- from torch import nn
- from ...activations import ACT2FN
- from ...cache_utils import Cache, DynamicCache, StaticCache
- from ...generation import GenerationMixin
- from ...modeling_attn_mask_utils import AttentionMaskConverter, _prepare_4d_causal_attention_mask
- from ...modeling_flash_attention_utils import is_flash_attn_available
- from ...modeling_layers import (
- GenericForSequenceClassification,
- GradientCheckpointingLayer,
- )
- from ...modeling_outputs import MoeCausalLMOutputWithPast, MoeModelOutputWithPast
- from ...modeling_rope_utils import ROPE_INIT_FUNCTIONS
- from ...modeling_utils import PreTrainedModel
- from ...utils import auto_docstring, can_return_tuple, is_torch_flex_attn_available, logging
- from ...utils.deprecation import deprecate_kwarg
- from .configuration_phimoe import PhimoeConfig
- if is_flash_attn_available():
- from ...modeling_flash_attention_utils import _flash_attention_forward
- if is_torch_flex_attn_available():
- from torch.nn.attention.flex_attention import BlockMask
- from ...integrations.flex_attention import make_flex_block_causal_mask
- # This makes `_prepare_4d_causal_attention_mask` a leaf function in the FX graph.
- # It means that the function will not be traced through and simply appear as a node in the graph.
- _prepare_4d_causal_attention_mask = torch.fx.wrap(_prepare_4d_causal_attention_mask)
- logger = logging.get_logger(__name__)
- # Copied from transformers.models.qwen2_moe.modeling_qwen2_moe.load_balancing_loss_func
- def load_balancing_loss_func(
- gate_logits: Union[torch.Tensor, tuple[torch.Tensor], None],
- num_experts: Optional[int] = None,
- top_k=2,
- attention_mask: Optional[torch.Tensor] = None,
- ) -> Union[torch.Tensor, int]:
- r"""
- Computes auxiliary load balancing loss as in Switch Transformer - implemented in Pytorch.
- See Switch Transformer (https://huggingface.co/papers/2101.03961) for more details. This function implements the loss
- function presented in equations (4) - (6) of the paper. It aims at penalizing cases where the routing between
- experts is too unbalanced.
- Args:
- gate_logits:
- Logits from the `gate`, should be a tuple of model.config.num_hidden_layers tensors of
- shape [batch_size X sequence_length, num_experts].
- num_experts:
- Number of experts
- top_k:
- The number of experts to route per-token, can be also interpreted as the `top-k` routing
- parameter.
- attention_mask (`torch.Tensor`, *optional*):
- The attention_mask used in forward function
- shape [batch_size X sequence_length] if not None.
- Returns:
- The auxiliary loss.
- """
- if gate_logits is None or not isinstance(gate_logits, tuple):
- return 0
- if isinstance(gate_logits, tuple):
- compute_device = gate_logits[0].device
- concatenated_gate_logits = torch.cat([layer_gate.to(compute_device) for layer_gate in gate_logits], dim=0)
- routing_weights = torch.nn.functional.softmax(concatenated_gate_logits, dim=-1)
- _, selected_experts = torch.topk(routing_weights, top_k, dim=-1)
- expert_mask = torch.nn.functional.one_hot(selected_experts, num_experts)
- if attention_mask is None:
- # Compute the percentage of tokens routed to each experts
- tokens_per_expert = torch.mean(expert_mask.float(), dim=0)
- # Compute the average probability of routing to these experts
- router_prob_per_expert = torch.mean(routing_weights, dim=0)
- else:
- batch_size, sequence_length = attention_mask.shape
- num_hidden_layers = concatenated_gate_logits.shape[0] // (batch_size * sequence_length)
- # Compute the mask that masks all padding tokens as 0 with the same shape of expert_mask
- expert_attention_mask = (
- attention_mask[None, :, :, None, None]
- .expand((num_hidden_layers, batch_size, sequence_length, top_k, num_experts))
- .reshape(-1, top_k, num_experts)
- .to(compute_device)
- )
- # Compute the percentage of tokens routed to each experts
- tokens_per_expert = torch.sum(expert_mask.float() * expert_attention_mask, dim=0) / torch.sum(
- expert_attention_mask, dim=0
- )
- # Compute the mask that masks all padding tokens as 0 with the same shape of tokens_per_expert
- router_per_expert_attention_mask = (
- attention_mask[None, :, :, None]
- .expand((num_hidden_layers, batch_size, sequence_length, routing_weights.shape[1]))
- .reshape(-1, routing_weights.shape[1])
- .to(compute_device)
- )
- # Compute the average probability of routing to these experts
- router_prob_per_expert = torch.sum(routing_weights * router_per_expert_attention_mask, dim=0) / torch.sum(
- router_per_expert_attention_mask, dim=0
- )
- device_index = routing_weights.device.index if routing_weights.device.index is not None else 0
- rank = routing_weights.shape[1] * int(device_index)
- overall_loss = torch.sum(
- tokens_per_expert[:, rank : rank + routing_weights.shape[1]] * router_prob_per_expert.unsqueeze(0)
- )
- return overall_loss * num_experts
- class PhimoeRotaryEmbedding(nn.Module):
- def __init__(
- self,
- config: Optional[PhimoeConfig] = None,
- ):
- super().__init__()
- self.config = config
- if config.rope_scaling is not None:
- self.rope_type = config.rope_scaling.get("rope_type", config.rope_scaling.get("type"))
- self.short_mscale = config.rope_scaling.get("short_mscale")
- self.long_mscale = config.rope_scaling.get("long_mscale")
- else:
- self.rope_type = "default"
- self.rope_init_fn = ROPE_INIT_FUNCTIONS[self.rope_type]
- def forward(self, x, seq_len=None):
- mscale = None
- if self.config.rope_scaling and seq_len:
- mscale = (
- self.long_mscale
- if seq_len > self.config.rope_scaling["original_max_position_embeddings"]
- else self.short_mscale
- )
- inv_freq, attention_scaling = self.rope_init_fn(self.config, x.device, seq_len)
- mscale = attention_scaling if mscale is None else mscale
- t = torch.arange(seq_len, device=x.device, dtype=torch.float32)
- freqs = torch.outer(t, inv_freq)
- emb = torch.cat((freqs, freqs), dim=-1)
- return (emb.cos() * mscale).to(x.dtype), (emb.sin() * mscale).to(x.dtype)
- # Copied from transformers.models.llama.modeling_llama.rotate_half
- 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, 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`):
- The position indices of the tokens corresponding to the query and key tensors. For example, this can be
- used to pass offsetted position ids when working with a KV-cache.
- 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[position_ids].unsqueeze(unsqueeze_dim)
- sin = sin[position_ids].unsqueeze(unsqueeze_dim)
- q_embed = (q * cos) + (rotate_half(q) * sin)
- k_embed = (k * cos) + (rotate_half(k) * sin)
- return q_embed, k_embed
- # Copied from transformers.models.llama.modeling_llama.repeat_kv
- 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)
- class PhimoeAttention(nn.Module):
- """
- Multi-headed attention from 'Attention Is All You Need' paper. Modified to use sliding window attention: Longformer
- and "Generating Long Sequences with Sparse Transformers".
- """
- def __init__(self, config: PhimoeConfig, layer_idx: Optional[int] = None):
- super().__init__()
- self.config = config
- self.layer_idx = layer_idx
- if layer_idx is None:
- logger.warning_once(
- f"Instantiating {self.__class__.__name__} without passing a `layer_idx` is not recommended and will "
- "lead to errors during the forward call if caching is used. Please make sure to provide a `layer_idx` "
- "when creating this class."
- )
- self.hidden_size = config.hidden_size
- self.num_heads = config.num_attention_heads
- self.head_dim = self.hidden_size // self.num_heads
- self.num_key_value_heads = config.num_key_value_heads
- self.num_key_value_groups = self.num_heads // self.num_key_value_heads
- self.max_position_embeddings = config.max_position_embeddings
- self.rope_theta = config.rope_theta
- self.is_causal = True
- self.attention_dropout = config.attention_dropout
- if (self.head_dim * self.num_heads) != self.hidden_size:
- raise ValueError(
- f"hidden_size must be divisible by num_heads (got `hidden_size`: {self.hidden_size}"
- f" and `num_heads`: {self.num_heads})."
- )
- self.q_proj = nn.Linear(self.hidden_size, self.num_heads * self.head_dim, bias=self.config.attention_bias)
- self.k_proj = nn.Linear(
- self.hidden_size, self.num_key_value_heads * self.head_dim, bias=self.config.attention_bias
- )
- self.v_proj = nn.Linear(
- self.hidden_size, self.num_key_value_heads * self.head_dim, bias=self.config.attention_bias
- )
- self.o_proj = nn.Linear(self.num_heads * self.head_dim, self.hidden_size, bias=self.config.attention_bias)
- def _shape(self, tensor: torch.Tensor, seq_len: int, bsz: int):
- return tensor.view(bsz, seq_len, self.num_heads, self.head_dim).transpose(1, 2).contiguous()
- @deprecate_kwarg("past_key_value", new_name="past_key_values", version="4.58")
- def forward(
- self,
- hidden_states: torch.Tensor,
- attention_mask: Optional[torch.Tensor] = None,
- position_ids: Optional[torch.LongTensor] = None,
- past_key_values: Optional[Cache] = None,
- output_attentions: bool = False,
- use_cache: bool = False,
- cache_position: Optional[torch.LongTensor] = None,
- position_embeddings: Optional[tuple[torch.Tensor, torch.Tensor]] = None,
- ) -> tuple[torch.Tensor, Optional[torch.Tensor], Optional[tuple[torch.Tensor]]]:
- bsz, q_len, _ = hidden_states.size()
- query_states = self.q_proj(hidden_states)
- key_states = self.k_proj(hidden_states)
- value_states = self.v_proj(hidden_states)
- query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
- key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
- value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
- cos, sin = position_embeddings
- query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin, position_ids)
- if past_key_values is not None:
- cache_kwargs = {"sin": sin, "cos": cos, "cache_position": cache_position} # Specific to RoPE models
- key_states, value_states = past_key_values.update(key_states, value_states, self.layer_idx, cache_kwargs)
- # repeat k/v heads if n_kv_heads < n_heads
- key_states = repeat_kv(key_states, self.num_key_value_groups)
- value_states = repeat_kv(value_states, self.num_key_value_groups)
- attn_weights = torch.matmul(query_states, key_states.transpose(2, 3)) / math.sqrt(self.head_dim)
- if attention_mask is not None: # no matter the length, we just slice it
- causal_mask = attention_mask[:, :, :, : key_states.shape[-2]]
- attn_weights = attn_weights + causal_mask
- # upcast attention to fp32
- attn_weights = nn.functional.softmax(attn_weights, dim=-1, dtype=torch.float32).to(query_states.dtype)
- attn_weights = nn.functional.dropout(attn_weights, p=self.attention_dropout, training=self.training)
- attn_output = torch.matmul(attn_weights, value_states)
- if attn_output.size() != (bsz, self.num_heads, q_len, self.head_dim):
- raise ValueError(
- f"`attn_output` should be of size {(bsz, self.num_heads, q_len, self.head_dim)}, but is"
- f" {attn_output.size()}"
- )
- attn_output = attn_output.transpose(1, 2).contiguous()
- attn_output = attn_output.reshape(bsz, q_len, self.hidden_size)
- attn_output = self.o_proj(attn_output)
- if not output_attentions:
- attn_weights = None
- return attn_output, attn_weights
- class PhimoeFlashAttention2(PhimoeAttention):
- """
- Phimoe flash attention module. This module inherits from `PhimoeAttention` as the weights of the module stays
- untouched. The only required change would be on the forward pass where it needs to correctly call the public API of
- flash attention and deal with padding tokens in case the input contains any of them.
- """
- @deprecate_kwarg("past_key_value", new_name="past_key_values", version="4.58")
- def forward(
- self,
- hidden_states: torch.Tensor,
- attention_mask: Optional[torch.Tensor] = None,
- position_ids: Optional[torch.LongTensor] = None,
- past_key_values: Optional[Cache] = None,
- output_attentions: bool = False,
- use_cache: bool = False,
- cache_position: Optional[torch.LongTensor] = None,
- position_embeddings: Optional[tuple[torch.Tensor, torch.Tensor]] = None,
- ):
- bsz, q_len, _ = hidden_states.size()
- query_states = self.q_proj(hidden_states)
- key_states = self.k_proj(hidden_states)
- value_states = self.v_proj(hidden_states)
- query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
- key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
- value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
- cos, sin = position_embeddings
- query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin, position_ids)
- if past_key_values is not None:
- cache_kwargs = {"sin": sin, "cos": cos, "cache_position": cache_position} # Specific to RoPE models
- key_states, value_states = past_key_values.update(key_states, value_states, self.layer_idx, cache_kwargs)
- # repeat k/v heads if n_kv_heads < n_heads
- key_states = repeat_kv(key_states, self.num_key_value_groups)
- value_states = repeat_kv(value_states, self.num_key_value_groups)
- dropout_rate = 0.0 if not self.training else self.attention_dropout
- # In PEFT, usually we cast the layer norms in float32 for training stability reasons
- # therefore the input hidden states gets silently casted in float32. Hence, we need
- # cast them back in float16 just to be sure everything works as expected.
- input_dtype = query_states.dtype
- device_type = query_states.device.type if query_states.device.type != "mps" else "cpu"
- if input_dtype == torch.float32:
- if torch.is_autocast_enabled():
- target_dtype = (
- torch.get_autocast_dtype(device_type)
- if hasattr(torch, "get_autocast_dtype")
- else torch.get_autocast_gpu_dtype()
- )
- # Handle the case where the model is quantized
- elif hasattr(self.config, "_pre_quantization_dtype"):
- target_dtype = self.config._pre_quantization_dtype
- else:
- target_dtype = self.q_proj.weight.dtype
- logger.warning_once(
- f"The input hidden states seems to be silently casted in float32, this might be related to"
- f" the fact you have upcasted embedding or layer norm layers in float32. We will cast back the input in"
- f" {target_dtype}."
- )
- query_states = query_states.to(target_dtype)
- key_states = key_states.to(target_dtype)
- value_states = value_states.to(target_dtype)
- # Reashape to the expected shape for Flash Attention
- query_states = query_states.transpose(1, 2)
- key_states = key_states.transpose(1, 2)
- value_states = value_states.transpose(1, 2)
- attn_output = _flash_attention_forward(
- query_states,
- key_states,
- value_states,
- attention_mask,
- q_len,
- position_ids=position_ids,
- dropout=dropout_rate,
- sliding_window=getattr(self.config, "sliding_window", None),
- is_causal=self.is_causal,
- )
- attn_output = attn_output.reshape(bsz, q_len, self.hidden_size).contiguous()
- attn_output = self.o_proj(attn_output)
- if not output_attentions:
- attn_weights = None
- return attn_output, attn_weights
- class PhimoeSdpaAttention(PhimoeAttention):
- """
- Phimoe attention module using torch.nn.functional.scaled_dot_product_attention. This module inherits from
- `PhimoeAttention` as the weights of the module stays untouched. The only changes are on the forward pass to adapt to
- SDPA API.
- """
- # Adapted from PhimoeAttention.forward
- @deprecate_kwarg("past_key_value", new_name="past_key_values", version="4.58")
- def forward(
- self,
- hidden_states: torch.Tensor,
- attention_mask: Optional[torch.Tensor] = None,
- position_ids: Optional[torch.LongTensor] = None,
- past_key_values: Optional[Cache] = None,
- output_attentions: bool = False,
- use_cache: bool = False,
- cache_position: Optional[torch.LongTensor] = None,
- position_embeddings: Optional[tuple[torch.Tensor, torch.Tensor]] = None,
- ) -> tuple[torch.Tensor, Optional[torch.Tensor], Optional[tuple[torch.Tensor]]]:
- if output_attentions:
- # TODO: Improve this warning with e.g. `model.config.attn_implementation = "manual"` once this is implemented.
- logger.warning_once(
- "PhimoeModel is using PhimoeSdpaAttention, but `torch.nn.functional.scaled_dot_product_attention` does not support `output_attentions=True`. Falling back to the manual attention implementation, "
- 'but specifying the manual implementation will be required from Transformers version v5.0.0 onwards. This warning can be removed using the argument `attn_implementation="eager"` when loading the model.'
- )
- return super().forward(
- hidden_states=hidden_states,
- attention_mask=attention_mask,
- position_ids=position_ids,
- past_key_values=past_key_values,
- output_attentions=output_attentions,
- use_cache=use_cache,
- position_embeddings=position_embeddings,
- )
- bsz, q_len, _ = hidden_states.size()
- query_states = self.q_proj(hidden_states)
- key_states = self.k_proj(hidden_states)
- value_states = self.v_proj(hidden_states)
- query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
- key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
- value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
- cos, sin = position_embeddings
- query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin, position_ids)
- if past_key_values is not None:
- cache_kwargs = {"sin": sin, "cos": cos, "cache_position": cache_position} # Specific to RoPE models
- key_states, value_states = past_key_values.update(key_states, value_states, self.layer_idx, cache_kwargs)
- key_states = repeat_kv(key_states, self.num_key_value_groups)
- value_states = repeat_kv(value_states, self.num_key_value_groups)
- causal_mask = attention_mask
- if attention_mask is not None: # no matter the length, we just slice it
- causal_mask = attention_mask[:, :, :, : key_states.shape[-2]]
- # SDPA with memory-efficient backend is currently (torch==2.1.2) bugged with non-contiguous inputs with custom attn_mask,
- # Reference: https://github.com/pytorch/pytorch/issues/112577.
- if query_states.device.type == "cuda" and attention_mask is not None:
- query_states = query_states.contiguous()
- key_states = key_states.contiguous()
- value_states = value_states.contiguous()
- # We dispatch to SDPA's Flash Attention or Efficient kernels via this `is_causal` if statement instead of an inline conditional assignment
- # in SDPA to support both torch.compile's dynamic shapes and full graph options. An inline conditional prevents dynamic shapes from compiling.
- # The q_len > 1 is necessary to match with AttentionMaskConverter.to_causal_4d that does not create a causal mask in case q_len == 1.
- is_causal = causal_mask is None and q_len > 1
- attn_output = torch.nn.functional.scaled_dot_product_attention(
- query_states,
- key_states,
- value_states,
- attn_mask=causal_mask,
- dropout_p=self.attention_dropout if self.training else 0.0,
- is_causal=is_causal,
- )
- attn_output = attn_output.transpose(1, 2).contiguous()
- attn_output = attn_output.view(bsz, q_len, self.hidden_size)
- attn_output = self.o_proj(attn_output)
- return attn_output, None
- PHIMOE_ATTENTION_CLASSES = {
- "eager": PhimoeAttention,
- "flash_attention_2": PhimoeFlashAttention2,
- "sdpa": PhimoeSdpaAttention,
- }
- # Copied from transformers.models.mixtral.modeling_mixtral.MixtralBlockSparseTop2MLP with Mixtral->Phimoe
- class PhimoeBlockSparseTop2MLP(nn.Module):
- def __init__(self, config: PhimoeConfig):
- super().__init__()
- self.ffn_dim = config.intermediate_size
- self.hidden_dim = config.hidden_size
- self.w1 = nn.Linear(self.hidden_dim, self.ffn_dim, bias=False)
- self.w2 = nn.Linear(self.ffn_dim, self.hidden_dim, bias=False)
- self.w3 = nn.Linear(self.hidden_dim, self.ffn_dim, bias=False)
- self.act_fn = ACT2FN[config.hidden_act]
- def forward(self, hidden_states):
- current_hidden_states = self.act_fn(self.w1(hidden_states)) * self.w3(hidden_states)
- current_hidden_states = self.w2(current_hidden_states)
- return current_hidden_states
- class MultiplierProcessor(torch.autograd.Function):
- @staticmethod
- def forward(
- ctx,
- scores: torch.Tensor,
- multiplier: torch.Tensor,
- selected_experts: torch.Tensor,
- masked_gates: torch.Tensor,
- mask_for_one: torch.Tensor,
- ):
- """
- Forward pass for the custom autograd function.
- Args:
- ctx: Context object to save information for backward computation.
- scores (torch.Tensor): Input scores tensor.
- multiplier (torch.Tensor): Multiplier tensor.
- selected_experts (torch.Tensor): Tensor of selected experts.
- masked_gates (torch.Tensor): Masked gates tensor.
- mask_for_one (torch.Tensor): Mask for one tensor.
- Returns:
- torch.Tensor: Result of the forward pass.
- """
- ctx.save_for_backward(multiplier, selected_experts, masked_gates)
- return multiplier * mask_for_one
- @staticmethod
- def backward(
- ctx,
- grad_at_output: torch.Tensor,
- ):
- """
- Backward pass for the custom autograd function.
- Args:
- ctx: Context object with saved tensors from the forward pass.
- grad_at_output (torch.Tensor): Gradient at the output.
- Returns:
- tuple[torch.Tensor, None, None, None, None]: Gradients for the inputs.
- """
- multiplier, selected_experts, masked_gates = ctx.saved_tensors
- grad_at_output = grad_at_output * multiplier
- grad_at_scores_expanded = masked_gates * grad_at_output.mul(-1)
- grad_at_scores_expanded.scatter_add_(
- dim=-1,
- index=selected_experts,
- src=grad_at_output,
- )
- return (
- grad_at_scores_expanded,
- None,
- None,
- None,
- None,
- )
- def sparsemixer(scores, jitter_eps, training, top_k=2):
- """
- Sparse mixer function to select top-k experts and compute multipliers.
- Based on the paper: https://huggingface.co/papers/2409.12136
- We first replace the TopK(·) function as random sampling of discrete variables
- in model training. Then, following Liu et al. (2023a) and Liu et al. (2023b), we apply Heun's
- third order method to approximate the expert routing gradient and construct a modified
- back-propagation to give a mathematically sound gradient estimation for expert routing.
- Args:
- scores (torch.Tensor): Input scores tensor.
- jitter_eps (float): Jitter epsilon for numerical stability.
- training (bool): Flag indicating if the model is in training mode.
- top_k (int): Number of top experts to select.
- Returns:
- tuple[torch.Tensor, torch.Tensor]: Multiplier and selected experts tensors.
- """
- if top_k != 2:
- raise ValueError("top_k must be equal to 2")
- # first expert
- with torch.no_grad():
- # Compute mask for sparsity
- mask_logits_threshold, max_ind = scores.max(dim=-1, keepdim=True)
- factor = scores.abs().clamp(min=mask_logits_threshold)
- mask_logits_threshold = ((mask_logits_threshold - scores) / factor) > (2 * jitter_eps)
- # Apply mask
- masked_gates = scores.masked_fill(mask_logits_threshold, float("-inf"))
- if training:
- selected_experts = (
- (
- masked_gates
- - torch.empty_like(masked_gates, memory_format=torch.legacy_contiguous_format).exponential_().log()
- )
- .max(dim=-1)[1]
- .unsqueeze(-1)
- ) # Gumbel sampling, more robust than the multinomial method
- else:
- selected_experts = max_ind
- # Compute scores for gradients
- masked_gates = torch.softmax(masked_gates, dim=-1)
- multiplier_o = masked_gates.gather(dim=-1, index=selected_experts)
- if training:
- # Compute midpoint mask
- max_scores, max_ind = masked_gates.max(dim=-1, keepdim=True)
- mask_for_one = torch.logical_or(
- selected_experts == max_ind,
- torch.rand_like(max_scores) > 0.75, # Heun's third-order method
- )
- # 1 -> 1.0 & 0 -> 1./3: lambda x: (x + 0.5) / 1.5
- mask_for_one = torch.add(0.3333, mask_for_one, alpha=0.6667).type_as(masked_gates)
- multiplier = MultiplierProcessor.apply(
- scores,
- multiplier_o,
- selected_experts,
- masked_gates,
- mask_for_one,
- )
- else:
- multiplier = multiplier_o
- # Masked out first expert
- masked_scores = torch.scatter(
- scores,
- -1,
- selected_experts,
- float("-inf"),
- )
- with torch.no_grad():
- # Compute mask for sparsity
- mask_logits_threshold, max_ind = masked_scores.max(dim=-1, keepdim=True)
- factor = scores.abs().clamp(min=mask_logits_threshold)
- mask_logits_threshold = ((mask_logits_threshold - scores) / factor) > (2 * jitter_eps)
- # Apply mask
- masked_gates_top2 = masked_scores.masked_fill(mask_logits_threshold, float("-inf"))
- if training:
- selected_experts_top2 = (
- (
- masked_gates_top2
- - torch.empty_like(masked_gates_top2, memory_format=torch.legacy_contiguous_format)
- .exponential_()
- .log()
- )
- .max(dim=-1)[1]
- .unsqueeze(-1)
- ) # Gumbel sampling, more robust than the multinomial method
- else:
- selected_experts_top2 = max_ind
- # Compute scores for gradients
- masked_gates_top2 = torch.softmax(masked_gates_top2, dim=-1)
- multiplier_top2_o = masked_gates_top2.gather(dim=-1, index=selected_experts_top2)
- if training:
- # Compute midpoint mask
- max_scores, max_ind = masked_gates_top2.max(dim=-1, keepdim=True)
- mask_for_one_top2 = torch.logical_or(
- selected_experts_top2 == max_ind,
- torch.rand_like(max_scores).uniform_() > 0.75, # Heun's third-order method
- )
- # 1 -> 1.0 & 0 -> 1./3: lambda x: (x + 0.5) / 1.5
- mask_for_one_top2 = torch.add(0.3333, mask_for_one_top2, alpha=0.6667).type_as(masked_gates_top2)
- multiplier_top2 = MultiplierProcessor.apply(
- scores,
- multiplier_top2_o,
- selected_experts_top2,
- masked_gates_top2,
- mask_for_one_top2,
- )
- else:
- multiplier_top2 = multiplier_top2_o
- multiplier = torch.concat((multiplier, multiplier_top2), dim=-1)
- selected_experts = torch.concat((selected_experts, selected_experts_top2), dim=-1)
- return (
- multiplier,
- selected_experts,
- )
- class PhimoeSparseMoeBlock(nn.Module):
- """
- This implementation is
- strictly equivalent to standard MoE with full capacity (no
- dropped tokens). It's faster since it formulates MoE operations
- in terms of block-sparse operations to accommodate imbalanced
- assignments of tokens to experts, whereas standard MoE either
- (1) drop tokens at the cost of reduced performance or (2) set
- capacity factor to number of experts and thus waste computation
- and memory on padding.
- """
- def __init__(self, config):
- super().__init__()
- self.hidden_dim = config.hidden_size
- self.ffn_dim = config.intermediate_size
- self.num_experts = config.num_local_experts
- self.top_k = config.num_experts_per_tok
- # gating
- self.gate = nn.Linear(self.hidden_dim, self.num_experts, bias=False)
- self.experts = nn.ModuleList([PhimoeBlockSparseTop2MLP(config) for _ in range(self.num_experts)])
- # Jitter parameters
- self.router_jitter_noise = config.router_jitter_noise
- self.input_jitter_noise = config.input_jitter_noise
- def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
- """ """
- batch_size, sequence_length, hidden_dim = hidden_states.shape
- if self.training and self.input_jitter_noise > 0:
- hidden_states *= torch.empty_like(hidden_states).uniform_(
- 1.0 - self.input_jitter_noise, 1.0 + self.input_jitter_noise
- )
- hidden_states = hidden_states.view(-1, hidden_dim)
- router_logits = self.gate(hidden_states)
- routing_weights, selected_experts = sparsemixer(
- router_logits,
- jitter_eps=self.router_jitter_noise,
- training=self.training,
- )
- final_hidden_states = torch.zeros(
- (batch_size * sequence_length, hidden_dim), dtype=hidden_states.dtype, device=hidden_states.device
- )
- # One hot encode the selected experts to create an expert mask
- # this will be used to easily index which expert is going to be sollicitated
- expert_mask = torch.nn.functional.one_hot(selected_experts, num_classes=self.num_experts).permute(2, 1, 0)
- # Loop over all available experts in the model and perform the computation on each expert
- for expert_idx in range(self.num_experts):
- expert_layer = self.experts[expert_idx]
- idx, top_x = torch.where(expert_mask[expert_idx])
- if top_x.shape[0] == 0:
- continue
- # Index the correct hidden states and compute the expert hidden state for
- # the current expert. We need to make sure to multiply the output hidden
- # states by `routing_weights` on the corresponding tokens (top-1 and top-2)
- current_state = hidden_states[None, top_x].reshape(-1, hidden_dim)
- current_hidden_states = expert_layer(current_state) * routing_weights[top_x, idx, None]
- # However `index_add_` only support torch tensors for indexing so we'll use
- # the `top_x` tensor here.
- final_hidden_states.index_add_(0, top_x, current_hidden_states.to(hidden_states.dtype))
- final_hidden_states = final_hidden_states.reshape(batch_size, sequence_length, hidden_dim)
- return final_hidden_states, router_logits
- class PhimoeDecoderLayer(GradientCheckpointingLayer):
- def __init__(self, config: PhimoeConfig, layer_idx: int):
- super().__init__()
- self.hidden_size = config.hidden_size
- self.self_attn = PHIMOE_ATTENTION_CLASSES[config._attn_implementation](config, layer_idx)
- self.block_sparse_moe = PhimoeSparseMoeBlock(config)
- self.input_layernorm = nn.LayerNorm(config.hidden_size, eps=config.rms_norm_eps, elementwise_affine=True)
- self.post_attention_layernorm = nn.LayerNorm(
- config.hidden_size, eps=config.rms_norm_eps, elementwise_affine=True
- )
- @deprecate_kwarg("past_key_value", new_name="past_key_values", version="4.58")
- def forward(
- self,
- hidden_states: torch.Tensor,
- attention_mask: Optional[torch.Tensor] = None,
- position_ids: Optional[torch.LongTensor] = None,
- past_key_values: Optional[Cache] = None,
- output_attentions: Optional[bool] = False,
- output_router_logits: Optional[bool] = False,
- use_cache: Optional[bool] = False,
- cache_position: Optional[torch.LongTensor] = None,
- position_embeddings: Optional[tuple[torch.Tensor, torch.Tensor]] = None,
- **kwargs,
- ) -> tuple[torch.FloatTensor, Optional[tuple[torch.FloatTensor, torch.FloatTensor]]]:
- """
- Args:
- hidden_states (`torch.FloatTensor`): input to the layer of shape `(batch, seq_len, embed_dim)`
- attention_mask (`torch.FloatTensor`, *optional*): attention mask of size
- `(batch, sequence_length)` where padding elements are indicated by 0.
- past_key_values (`Cache`, *optional*): cached past key and value projection states
- output_attentions (`bool`, *optional*):
- Whether or not to return the attentions tensors of all attention layers. See `attentions` under
- returned tensors for more detail.
- output_router_logits (`bool`, *optional*):
- Whether or not to return the logits of all the routers. They are useful for computing the router loss, and
- should not be returned during inference.
- use_cache (`bool`, *optional*):
- If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding
- (see `past_key_values`).
- cache_position (`torch.LongTensor` of shape `(sequence_length)`, *optional*):
- Indices depicting the position of the input sequence tokens in the sequence.
- kwargs (`dict`, *optional*):
- Arbitrary kwargs to be ignored, used for FSDP and other methods that injects code
- into the model
- """
- residual = hidden_states
- hidden_states = self.input_layernorm(hidden_states)
- # Self Attention
- hidden_states, self_attn_weights = self.self_attn(
- hidden_states=hidden_states,
- attention_mask=attention_mask,
- position_ids=position_ids,
- past_key_values=past_key_values,
- output_attentions=output_attentions,
- use_cache=use_cache,
- cache_position=cache_position,
- position_embeddings=position_embeddings,
- )
- hidden_states = residual + hidden_states
- # Fully Connected
- residual = hidden_states
- hidden_states = self.post_attention_layernorm(hidden_states)
- hidden_states, router_logits = self.block_sparse_moe(hidden_states)
- hidden_states = residual + hidden_states
- outputs = (hidden_states,)
- if output_attentions:
- outputs += (self_attn_weights,)
- if output_router_logits:
- outputs += (router_logits,)
- return outputs
- @auto_docstring
- class PhimoePreTrainedModel(PreTrainedModel):
- config: PhimoeConfig
- base_model_prefix = "model"
- supports_gradient_checkpointing = True
- _no_split_modules = ["PhimoeDecoderLayer"]
- _skip_keys_device_placement = ["past_key_values"]
- _supports_flash_attn = True
- _supports_sdpa = True
- _can_compile_fullgraph = False # MoE models don't work with torch.compile (`torch.where(condition)` not supported)
- def _init_weights(self, module):
- std = self.config.initializer_range
- if isinstance(module, nn.Linear):
- module.weight.data.normal_(mean=0.0, std=std)
- if module.bias is not None:
- module.bias.data.zero_()
- elif isinstance(module, nn.Embedding):
- module.weight.data.normal_(mean=0.0, std=std)
- if module.padding_idx is not None:
- module.weight.data[module.padding_idx].zero_()
- elif isinstance(module, nn.LayerNorm):
- module.bias.data.zero_()
- module.weight.data.fill_(1.0)
- @auto_docstring
- class PhimoeModel(PhimoePreTrainedModel):
- """
- Transformer decoder consisting of *config.num_hidden_layers* layers. Each layer is a [`PhimoeDecoderLayer`]
- Args:
- config: PhimoeConfig
- """
- def __init__(self, config: PhimoeConfig):
- 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(
- [PhimoeDecoderLayer(config, layer_idx) for layer_idx in range(config.num_hidden_layers)]
- )
- self._attn_implementation = config._attn_implementation
- self.norm = nn.LayerNorm(config.hidden_size, eps=config.rms_norm_eps, elementwise_affine=True)
- self.rotary_emb = PhimoeRotaryEmbedding(config=config)
- self.gradient_checkpointing = False
- # Initialize weights and apply final processing
- self.post_init()
- @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,
- use_cache: Optional[bool] = None,
- output_attentions: Optional[bool] = None,
- output_hidden_states: Optional[bool] = None,
- output_router_logits: Optional[bool] = None,
- cache_position: Optional[torch.LongTensor] = None,
- ) -> MoeModelOutputWithPast:
- output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
- output_router_logits = (
- output_router_logits if output_router_logits is not None else self.config.output_router_logits
- )
- output_hidden_states = (
- output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
- )
- use_cache = use_cache if use_cache is not None else self.config.use_cache
- if (input_ids is None) ^ (inputs_embeds is not None):
- raise ValueError(
- "You cannot specify both input_ids and inputs_embeds at the same time, and must specify either one"
- )
- if self.gradient_checkpointing and self.training:
- if use_cache:
- logger.warning_once(
- "`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..."
- )
- use_cache = False
- if use_cache and past_key_values is None:
- past_key_values = DynamicCache(config=self.config)
- if inputs_embeds is None:
- inputs_embeds = self.embed_tokens(input_ids)
- 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 = self._update_causal_mask(
- attention_mask, inputs_embeds, cache_position, past_key_values, output_attentions
- )
- hidden_states = inputs_embeds
- position_embeddings = self.rotary_emb(hidden_states, seq_len=cache_position[-1] + 1)
- # decoder layers
- all_hidden_states = () if output_hidden_states else None
- all_self_attns = () if output_attentions else None
- all_router_logits = () if output_router_logits else None
- for decoder_layer in self.layers:
- if output_hidden_states:
- all_hidden_states += (hidden_states,)
- layer_outputs = decoder_layer(
- hidden_states,
- attention_mask=causal_mask,
- position_ids=position_ids,
- past_key_values=past_key_values,
- output_attentions=output_attentions,
- output_router_logits=output_router_logits,
- use_cache=use_cache,
- cache_position=cache_position,
- position_embeddings=position_embeddings,
- )
- hidden_states = layer_outputs[0]
- if output_attentions:
- all_self_attns += (layer_outputs[1],)
- if output_router_logits:
- all_router_logits += (layer_outputs[-1],)
- hidden_states = self.norm(hidden_states)
- # add hidden states from the last decoder layer
- if output_hidden_states:
- all_hidden_states += (hidden_states,)
- return MoeModelOutputWithPast(
- last_hidden_state=hidden_states,
- past_key_values=past_key_values,
- hidden_states=all_hidden_states,
- attentions=all_self_attns,
- router_logits=all_router_logits,
- )
- def _update_causal_mask(
- self,
- attention_mask: Union[torch.Tensor, "BlockMask"],
- input_tensor: torch.Tensor,
- cache_position: torch.Tensor,
- past_key_values: Cache,
- output_attentions: bool = False,
- ):
- if self.config._attn_implementation == "flash_attention_2":
- if attention_mask is not None and past_key_values is not None:
- is_padding_right = attention_mask[:, -1].sum().item() != input_tensor.size()[0]
- if is_padding_right:
- raise ValueError(
- "You are attempting to perform batched generation with padding_side='right'"
- " this may lead to unexpected behaviour for Flash Attention version of Phimoe. Make sure to "
- " call `tokenizer.padding_side = 'left'` before tokenizing the input. "
- )
- if attention_mask is not None and 0.0 in attention_mask:
- return attention_mask
- return None
- if self.config._attn_implementation == "flex_attention":
- if isinstance(attention_mask, torch.Tensor):
- attention_mask = make_flex_block_causal_mask(attention_mask)
- return attention_mask
- # For SDPA, when possible, we will rely on its `is_causal` argument instead of its `attn_mask` argument, in
- # order to dispatch on Flash Attention 2. This feature is not compatible with static cache, as SDPA will fail
- # to infer the attention mask.
- past_seen_tokens = past_key_values.get_seq_length() if past_key_values is not None else 0
- using_static_cache = isinstance(past_key_values, StaticCache)
- # When output attentions is True, sdpa implementation's forward method calls the eager implementation's forward
- if self.config._attn_implementation == "sdpa" and not using_static_cache and not output_attentions:
- if AttentionMaskConverter._ignore_causal_mask_sdpa(
- attention_mask,
- inputs_embeds=input_tensor,
- past_key_values_length=past_seen_tokens,
- sliding_window=self.config.sliding_window,
- is_training=self.training,
- ):
- return None
- dtype = input_tensor.dtype
- min_dtype = torch.finfo(dtype).min
- sequence_length = input_tensor.shape[1]
- # StaticCache
- if using_static_cache:
- target_length = past_key_values.get_max_cache_shape()
- # DynamicCache or no cache
- else:
- target_length = (
- attention_mask.shape[-1]
- if isinstance(attention_mask, torch.Tensor)
- else past_seen_tokens + sequence_length + 1
- )
- # In case the provided `attention` mask is 2D, we generate a causal mask here (4D).
- causal_mask = self._prepare_4d_causal_attention_mask_with_cache_position(
- attention_mask,
- sequence_length=sequence_length,
- target_length=target_length,
- dtype=dtype,
- cache_position=cache_position,
- batch_size=input_tensor.shape[0],
- config=self.config,
- past_key_values=past_key_values,
- )
- if (
- self.config._attn_implementation == "sdpa"
- and attention_mask is not None
- and attention_mask.device.type in ["cuda", "xpu", "npu"]
- and not output_attentions
- ):
- # Attend to all tokens in fully masked rows in the causal_mask, for example the relevant first rows when
- # using left padding. This is required by F.scaled_dot_product_attention memory-efficient attention path.
- # Details: https://github.com/pytorch/pytorch/issues/110213
- causal_mask = AttentionMaskConverter._unmask_unattended(causal_mask, min_dtype)
- return causal_mask
- @staticmethod
- def _prepare_4d_causal_attention_mask_with_cache_position(
- attention_mask: torch.Tensor,
- sequence_length: int,
- target_length: int,
- dtype: torch.dtype,
- cache_position: torch.Tensor,
- batch_size: int,
- config: PhimoeConfig,
- past_key_values: Cache,
- ):
- """
- Creates a causal 4D mask of shape `(batch_size, 1, query_length, key_value_length)` from a 2D mask of shape
- `(batch_size, key_value_length)`, or if the input `attention_mask` is already 4D, do nothing.
- Args:
- attention_mask (`torch.Tensor`):
- A 2D attention mask of shape `(batch_size, key_value_length)` or a 4D attention mask of shape `(batch_size, 1, query_length, key_value_length)`.
- sequence_length (`int`):
- The sequence length being processed.
- target_length (`int`):
- The target length: when generating with static cache, the mask should be as long as the static cache, to account for the 0 padding, the part of the cache that is not filled yet.
- dtype (`torch.dtype`):
- The dtype to use for the 4D attention mask.
- cache_position (`torch.Tensor`):
- Indices depicting the position of the input sequence tokens in the sequence.
- batch_size (`torch.Tensor`):
- Batch size.
- config (`PhimoeConfig`):
- The model's configuration class
- past_key_values (`Cache`):
- The cache class that is being used currently to generate
- """
- if attention_mask is not None and attention_mask.dim() == 4:
- # In this case we assume that the mask comes already in inverted form and requires no inversion or slicing.
- causal_mask = attention_mask
- else:
- min_dtype = torch.finfo(dtype).min
- causal_mask = torch.full(
- (sequence_length, target_length), fill_value=min_dtype, dtype=dtype, device=cache_position.device
- )
- diagonal_attend_mask = torch.arange(target_length, device=cache_position.device) > cache_position.reshape(
- -1, 1
- )
- text_config = config.get_text_config()
- if getattr(text_config, "use_sliding_window", True) and text_config.sliding_window is not None:
- # if we have sliding window, we should not attend to tokens beyond sliding window length, so we mask them out also
- # the check is needed to verify is current checkpoint was trained with sliding window or not
- is_static_sliding_cache = isinstance(past_key_values, StaticCache) and all(past_key_values.is_sliding)
- if not is_static_sliding_cache or sequence_length > target_length:
- sliding_attend_mask = torch.arange(target_length, device=cache_position.device) <= (
- cache_position.reshape(-1, 1) - text_config.sliding_window
- )
- diagonal_attend_mask.bitwise_or_(sliding_attend_mask)
- causal_mask *= diagonal_attend_mask
- causal_mask = causal_mask[None, None, :, :].expand(batch_size, 1, -1, -1)
- if attention_mask is not None:
- causal_mask = causal_mask.clone() # copy to contiguous memory for in-place edit
- if attention_mask.shape[-1] > target_length:
- attention_mask = attention_mask[:, :target_length]
- mask_length = attention_mask.shape[-1]
- padding_mask = causal_mask[:, :, :, :mask_length] + attention_mask[:, None, None, :].to(
- causal_mask.device
- )
- padding_mask = padding_mask == 0
- causal_mask[:, :, :, :mask_length] = causal_mask[:, :, :, :mask_length].masked_fill(
- padding_mask, min_dtype
- )
- return causal_mask
- class PhimoeForCausalLM(PhimoePreTrainedModel, GenerationMixin):
- _tied_weights_keys = ["lm_head.weight"]
- def __init__(self, config):
- super().__init__(config)
- self.model = PhimoeModel(config)
- self.vocab_size = config.vocab_size
- self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=self.config.lm_head_bias)
- self.router_aux_loss_coef = config.router_aux_loss_coef
- self.num_experts = config.num_local_experts
- self.num_experts_per_tok = config.num_experts_per_tok
- # Initialize weights and apply final processing
- self.post_init()
- @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,
- output_attentions: Optional[bool] = None,
- output_hidden_states: Optional[bool] = None,
- output_router_logits: Optional[bool] = None,
- cache_position: Optional[torch.LongTensor] = None,
- logits_to_keep: Union[int, torch.Tensor] = 0,
- **kwargs,
- ) -> MoeCausalLMOutputWithPast:
- r"""
- labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
- Labels for computing the masked language modeling loss. Indices should either be in `[0, ...,
- config.vocab_size]` or -100 (see `input_ids` docstring). Tokens with indices set to `-100` are ignored
- (masked), the loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`.
- Example:
- ```python
- >>> from transformers import AutoTokenizer, PhimoeForCausalLM
- >>> model = PhimoeForCausalLM.from_pretrained("microsoft/Phi-3.5-MoE-instruct")
- >>> tokenizer = AutoTokenizer.from_pretrained("microsoft/Phi-3.5-MoE-instruct")
- >>> 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."
- ```"""
- if (
- use_cache
- and self.config.rope_scaling
- and cache_position is not None
- and cache_position[0] == self.config.original_max_position_embeddings
- ):
- logger.warning(
- f"If you are not using the generate method, you may encounter nonsensical outputs after the {self.config.original_max_position_embeddings}th token, as the KV cache needs to be recomputed."
- )
- output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
- output_router_logits = (
- output_router_logits if output_router_logits is not None else self.config.output_router_logits
- )
- output_hidden_states = (
- output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
- )
- # decoder outputs consists of (dec_features, layer_state, dec_hidden, dec_attn)
- outputs: MoeModelOutputWithPast = 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,
- output_attentions=output_attentions,
- output_hidden_states=output_hidden_states,
- output_router_logits=output_router_logits,
- cache_position=cache_position,
- )
- 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, labels, self.vocab_size, **kwargs)
- aux_loss = None
- if output_router_logits:
- aux_loss = load_balancing_loss_func(
- outputs.router_logits,
- self.num_experts,
- self.num_experts_per_tok,
- attention_mask,
- )
- if labels is not None:
- loss += self.router_aux_loss_coef * aux_loss.to(loss.device) # make sure to reside in the same device
- return MoeCausalLMOutputWithPast(
- loss=loss,
- aux_loss=aux_loss,
- logits=logits,
- past_key_values=outputs.past_key_values,
- hidden_states=outputs.hidden_states,
- attentions=outputs.attentions,
- router_logits=outputs.router_logits,
- )
- # Copied from transformers.models.phi3.modeling_phi3.Phi3ForCausalLM.prepare_inputs_for_generation
- def prepare_inputs_for_generation(
- self,
- input_ids,
- past_key_values=None,
- attention_mask=None,
- inputs_embeds=None,
- cache_position=None,
- position_ids=None,
- use_cache=True,
- logits_to_keep=None,
- **kwargs,
- ):
- # Overwritten -- this model may need to switch between short and long rope, invalidating the cache in the
- # process
- # When the first time input length reached long and short factor switching point, enforce re-compute cache
- # It will cause downside of slower at this single token position, however, better than current failure.
- if (
- past_key_values
- and self.config.rope_scaling
- and input_ids.shape[1] >= self.config.original_max_position_embeddings + 1
- ):
- past_length = cache_position[0]
- if past_length <= self.config.original_max_position_embeddings:
- past_key_values = None
- model_inputs = super().prepare_inputs_for_generation(
- input_ids=input_ids,
- past_key_values=past_key_values,
- attention_mask=attention_mask,
- inputs_embeds=inputs_embeds,
- cache_position=cache_position,
- position_ids=position_ids,
- use_cache=use_cache,
- logits_to_keep=logits_to_keep,
- **kwargs,
- )
- return model_inputs
- class PhimoeForSequenceClassification(GenericForSequenceClassification, PhimoePreTrainedModel): ...
- __all__ = [
- "PhimoePreTrainedModel",
- "PhimoeModel",
- "PhimoeForCausalLM",
- "PhimoeForSequenceClassification",
- ]
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