Update codes to be in line with LLM-foundry update on October 30, 2023
#1
by
xianbin
- opened
- hf_prefixlm_converter.py +99 -263
hf_prefixlm_converter.py
CHANGED
@@ -6,25 +6,24 @@ Causal LM to convert it to a Prefix LM.
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Prefix LMs accepts a `bidirectional_mask` input in `forward`
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and treat the input prompt as the prefix in `generate`.
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"""
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import math
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import warnings
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from types import MethodType
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from typing import Any, List, MutableMapping, Optional, Tuple, Union
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import torch
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from transformers.models.bloom.modeling_bloom import BaseModelOutputWithPastAndCrossAttentions, BloomForCausalLM, BloomModel, CausalLMOutputWithCrossAttentions, CrossEntropyLoss
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from transformers.models.bloom.modeling_bloom import _expand_mask as _expand_mask_bloom
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from transformers.models.bloom.modeling_bloom import _make_causal_mask as _make_causal_mask_bloom
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from transformers.models.bloom.modeling_bloom import logging
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from transformers.models.gpt2.modeling_gpt2 import GPT2LMHeadModel
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from transformers.models.gpt_neo.modeling_gpt_neo import GPTNeoForCausalLM
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from transformers.models.gpt_neox.modeling_gpt_neox import GPTNeoXForCausalLM
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from transformers.models.gptj.modeling_gptj import GPTJForCausalLM
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def _convert_gpt_causal_lm_to_prefix_lm(model: CAUSAL_GPT_TYPES) -> CAUSAL_GPT_TYPES:
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"""Converts a GPT-style Causal LM to a Prefix LM.
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@@ -37,10 +36,12 @@ def _convert_gpt_causal_lm_to_prefix_lm(model: CAUSAL_GPT_TYPES) -> CAUSAL_GPT_T
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See `convert_hf_causal_lm_to_prefix_lm` for more details.
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"""
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if hasattr(model,
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return model
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assert isinstance(model, _SUPPORTED_GPT_MODELS)
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assert
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def _get_attn_modules(model: CAUSAL_GPT_TYPES) -> List[torch.nn.Module]:
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"""Helper that gets a list of the model's attention modules.
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@@ -56,7 +57,7 @@ def _convert_gpt_causal_lm_to_prefix_lm(model: CAUSAL_GPT_TYPES) -> CAUSAL_GPT_T
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blocks = model.transformer.h
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for block in blocks:
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if isinstance(model, GPTNeoForCausalLM):
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if block.attn.attention_type !=
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continue
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attn_module = block.attn.attention
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elif isinstance(model, GPTNeoXForCausalLM):
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@@ -65,17 +66,58 @@ def _convert_gpt_causal_lm_to_prefix_lm(model: CAUSAL_GPT_TYPES) -> CAUSAL_GPT_T
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attn_module = block.attn
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attn_modules.append(attn_module)
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return attn_modules
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setattr(model, '_original_forward', getattr(model, 'forward'))
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setattr(model, '_original_generate', getattr(model, 'generate'))
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"""Wraps original forward to enable PrefixLM attention."""
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def call_og_forward():
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if isinstance(self, GPTNeoXForCausalLM):
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return self._original_forward(
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else:
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return self._original_forward(
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if bidirectional_mask is None:
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return call_og_forward()
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assert isinstance(bidirectional_mask, torch.Tensor)
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@@ -83,15 +125,24 @@ def _convert_gpt_causal_lm_to_prefix_lm(model: CAUSAL_GPT_TYPES) -> CAUSAL_GPT_T
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(b, s) = bidirectional_mask.shape
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max_length = attn_modules[0].bias.shape[-1]
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if s > max_length:
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raise ValueError(
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assert s <= max_length
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if s < max_length:
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pad = torch.zeros(
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bidirectional_mask = torch.cat([bidirectional_mask, pad], dim=1)
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bidirectional = bidirectional_mask.unsqueeze(1).unsqueeze(1)
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for attn_module in attn_modules:
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assert isinstance(attn_module.bias, torch.Tensor)
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attn_module.bias.data = torch.logical_or(
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output = call_og_forward()
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for attn_module in attn_modules:
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attn_module.bias.data = torch.tril(attn_module.bias.data[0, 0])[None, None]
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@@ -106,236 +157,18 @@ def _convert_gpt_causal_lm_to_prefix_lm(model: CAUSAL_GPT_TYPES) -> CAUSAL_GPT_T
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for attn_module in attn_modules:
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attn_module.bias.data = torch.tril(attn_module.bias.data[0, 0])[None, None]
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return output
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setattr(model, 'forward', MethodType(forward, model))
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setattr(model, 'generate', MethodType(generate, model))
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setattr(model, '_prefix_lm_converted', True)
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return model
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def _convert_bloom_causal_lm_to_prefix_lm(model: BloomForCausalLM) -> BloomForCausalLM:
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"""Converts a BLOOM Causal LM to a Prefix LM.
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Supported HuggingFace model classes:
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- `BloomForCausalLM`
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""
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return model
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assert isinstance(model, BloomForCausalLM)
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assert model.config.add_cross_attention == False, 'Only supports BLOOM decoder-only models'
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def _prepare_attn_mask(self: BloomModel, attention_mask: torch.Tensor, bidirectional_mask: Optional[torch.Tensor], input_shape: Tuple[int, int], past_key_values_length: int) -> torch.BoolTensor:
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combined_attention_mask = None
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device = attention_mask.device
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(_, src_length) = input_shape
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if src_length > 1:
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combined_attention_mask = _make_causal_mask_bloom(input_shape, device=device, past_key_values_length=past_key_values_length)
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if bidirectional_mask is not None:
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assert attention_mask.shape == bidirectional_mask.shape
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expanded_bidirectional_mask = _expand_mask_bloom(bidirectional_mask, tgt_length=src_length)
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combined_attention_mask = torch.logical_and(combined_attention_mask, expanded_bidirectional_mask)
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expanded_attn_mask = _expand_mask_bloom(attention_mask, tgt_length=src_length)
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combined_attention_mask = expanded_attn_mask if combined_attention_mask is None else expanded_attn_mask | combined_attention_mask
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return combined_attention_mask
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def _build_alibi_tensor(self: BloomModel, batch_size: int, query_length: int, key_length: int, dtype: torch.dtype, device: torch.device) -> torch.Tensor:
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num_heads = self.config.n_head
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closest_power_of_2 = 2 ** math.floor(math.log2(num_heads))
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base = torch.tensor(2 ** (-2 ** (-(math.log2(closest_power_of_2) - 3))), device=device, dtype=torch.float32)
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powers = torch.arange(1, 1 + closest_power_of_2, device=device, dtype=torch.int32)
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slopes = torch.pow(base, powers)
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if closest_power_of_2 != num_heads:
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extra_base = torch.tensor(2 ** (-2 ** (-(math.log2(2 * closest_power_of_2) - 3))), device=device, dtype=torch.float32)
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num_remaining_heads = min(closest_power_of_2, num_heads - closest_power_of_2)
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extra_powers = torch.arange(1, 1 + 2 * num_remaining_heads, 2, device=device, dtype=torch.int32)
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slopes = torch.cat([slopes, torch.pow(extra_base, extra_powers)], dim=0)
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qa = torch.arange(query_length, device=device, dtype=torch.int32).view(-1, 1)
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ka = torch.arange(key_length, device=device, dtype=torch.int32).view(1, -1)
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diffs = qa - ka + key_length - query_length
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diffs = -diffs.abs()
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alibi = slopes.view(1, num_heads, 1, 1) * diffs.view(1, 1, query_length, key_length)
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alibi = alibi.expand(batch_size, -1, -1, -1).reshape(-1, query_length, key_length)
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return alibi.to(dtype)
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KeyValueT = Tuple[torch.Tensor, torch.Tensor]
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def transformer_forward(self: BloomModel, input_ids: Optional[torch.LongTensor]=None, past_key_values: Optional[Tuple[KeyValueT, ...]]=None, attention_mask: Optional[torch.Tensor]=None, bidirectional_mask: Optional[torch.Tensor]=None, head_mask: Optional[torch.LongTensor]=None, inputs_embeds: Optional[torch.LongTensor]=None, use_cache: Optional[bool]=None, output_attentions: Optional[bool]=None, output_hidden_states: Optional[bool]=None, return_dict: Optional[bool]=None, **deprecated_arguments: Any) -> Union[Tuple[torch.Tensor, ...], BaseModelOutputWithPastAndCrossAttentions]:
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if deprecated_arguments.pop('position_ids', False) is not False:
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warnings.warn('`position_ids` have no functionality in BLOOM and will be removed in v5.0.0. ' + 'You can safely ignore passing `position_ids`.', FutureWarning)
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if len(deprecated_arguments) > 0:
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raise ValueError(f'Got unexpected arguments: {deprecated_arguments}')
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output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
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output_hidden_states = output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
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use_cache = use_cache if use_cache is not None else self.config.use_cache
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return_dict = return_dict if return_dict is not None else self.config.use_return_dict
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if input_ids is not None and inputs_embeds is not None:
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raise ValueError('You cannot specify both input_ids and inputs_embeds at the same time')
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elif input_ids is not None:
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(batch_size, seq_length) = input_ids.shape
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elif inputs_embeds is not None:
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(batch_size, seq_length, _) = inputs_embeds.shape
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else:
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raise ValueError('You have to specify either input_ids or inputs_embeds')
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if past_key_values is None:
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past_key_values = tuple([None] * len(self.h))
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head_mask = self.get_head_mask(head_mask, self.config.n_layer)
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if inputs_embeds is None:
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inputs_embeds = self.word_embeddings(input_ids)
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hidden_states = self.word_embeddings_layernorm(inputs_embeds)
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presents = () if use_cache else None
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all_self_attentions = () if output_attentions else None
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all_hidden_states = () if output_hidden_states else None
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seq_length_with_past = seq_length
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past_key_values_length = 0
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if past_key_values[0] is not None:
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tmp = past_key_values[0][0]
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past_key_values_length = tmp.shape[2]
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seq_length_with_past = seq_length_with_past + past_key_values_length
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if attention_mask is None:
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attention_mask = torch.ones((batch_size, seq_length_with_past), device=hidden_states.device)
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else:
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attention_mask = attention_mask.to(hidden_states.device)
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alibi = self._build_alibi_tensor(batch_size=batch_size, query_length=seq_length, key_length=seq_length_with_past, dtype=hidden_states.dtype, device=hidden_states.device)
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causal_mask = self._prepare_attn_mask(attention_mask, bidirectional_mask, input_shape=(batch_size, seq_length), past_key_values_length=past_key_values_length)
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for (i, (block, layer_past)) in enumerate(zip(self.h, past_key_values)):
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if output_hidden_states:
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hst = (hidden_states,)
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all_hidden_states = all_hidden_states + hst
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if self.gradient_checkpointing and self.training:
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if use_cache:
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logger.warning('`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`...')
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use_cache = False
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def create_custom_forward(module: torch.nn.Module):
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def custom_forward(*inputs: Any):
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return module(*inputs, use_cache=use_cache, output_attentions=output_attentions)
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return custom_forward
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outputs = torch.utils.checkpoint.checkpoint(create_custom_forward(block), hidden_states, alibi, causal_mask, head_mask[i])
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else:
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outputs = block(hidden_states, layer_past=layer_past, attention_mask=causal_mask, head_mask=head_mask[i], use_cache=use_cache, output_attentions=output_attentions, alibi=alibi)
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hidden_states = outputs[0]
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if use_cache is True:
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presents = presents + (outputs[1],)
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if output_attentions:
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oa = (outputs[2 if use_cache else 1],)
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all_self_attentions = all_self_attentions + oa
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hidden_states = self.ln_f(hidden_states)
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if output_hidden_states:
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hst = (hidden_states,)
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all_hidden_states = all_hidden_states + hst
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if not return_dict:
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return tuple((v for v in [hidden_states, presents, all_hidden_states, all_self_attentions] if v is not None))
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return BaseModelOutputWithPastAndCrossAttentions(last_hidden_state=hidden_states, past_key_values=presents, hidden_states=all_hidden_states, attentions=all_self_attentions)
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setattr(model.transformer, '_prepare_attn_mask', MethodType(_prepare_attn_mask, model.transformer))
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setattr(model.transformer, '_build_alibi_tensor', MethodType(_build_alibi_tensor, model.transformer))
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setattr(model.transformer, 'forward', MethodType(transformer_forward, model.transformer))
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KeyValueT = Tuple[torch.Tensor, torch.Tensor]
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def forward(self: BloomForCausalLM, input_ids: Optional[torch.LongTensor]=None, past_key_values: Optional[Tuple[KeyValueT, ...]]=None, attention_mask: Optional[torch.Tensor]=None, bidirectional_mask: Optional[torch.Tensor]=None, head_mask: Optional[torch.Tensor]=None, inputs_embeds: Optional[torch.Tensor]=None, labels: Optional[torch.Tensor]=None, use_cache: Optional[bool]=None, output_attentions: Optional[bool]=None, output_hidden_states: Optional[bool]=None, return_dict: Optional[bool]=None, **deprecated_arguments: Any) -> Union[Tuple[torch.Tensor], CausalLMOutputWithCrossAttentions]:
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"""Replacement forward method for BloomCausalLM."""
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if deprecated_arguments.pop('position_ids', False) is not False:
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warnings.warn('`position_ids` have no functionality in BLOOM and will be removed ' + 'in v5.0.0. You can safely ignore passing `position_ids`.', FutureWarning)
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if len(deprecated_arguments) > 0:
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raise ValueError(f'Got unexpected arguments: {deprecated_arguments}')
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return_dict = return_dict if return_dict is not None else self.config.use_return_dict
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transformer_outputs = self.transformer(input_ids, past_key_values=past_key_values, attention_mask=attention_mask, bidirectional_mask=bidirectional_mask, head_mask=head_mask, inputs_embeds=inputs_embeds, use_cache=use_cache, output_attentions=output_attentions, output_hidden_states=output_hidden_states, return_dict=return_dict)
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hidden_states = transformer_outputs[0]
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lm_logits = self.lm_head(hidden_states)
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loss = None
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if labels is not None:
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shift_logits = lm_logits[..., :-1, :].contiguous()
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shift_labels = labels[..., 1:].contiguous()
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(batch_size, seq_length, vocab_size) = shift_logits.shape
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loss_fct = CrossEntropyLoss()
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loss = loss_fct(shift_logits.view(batch_size * seq_length, vocab_size), shift_labels.view(batch_size * seq_length))
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if not return_dict:
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output = (lm_logits,) + transformer_outputs[1:]
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return (loss,) + output if loss is not None else output
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return CausalLMOutputWithCrossAttentions(loss=loss, logits=lm_logits, past_key_values=transformer_outputs.past_key_values, hidden_states=transformer_outputs.hidden_states, attentions=transformer_outputs.attentions)
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def prepare_inputs_for_generation(self: BloomForCausalLM, input_ids: torch.LongTensor, past: Optional[torch.Tensor]=None, attention_mask: Optional[torch.Tensor]=None, **kwargs: Any) -> dict:
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del kwargs
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if past:
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input_ids = input_ids[:, -1].unsqueeze(-1)
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bidirectional_mask = None
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if past[0][0].shape[0] == input_ids.shape[0]:
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past = self._convert_to_bloom_cache(past)
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else:
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bidirectional_mask = torch.ones_like(input_ids)
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return {'input_ids': input_ids, 'past_key_values': past, 'use_cache': True, 'attention_mask': attention_mask, 'bidirectional_mask': bidirectional_mask}
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setattr(model, 'forward', MethodType(forward, model))
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setattr(model, 'prepare_inputs_for_generation', MethodType(prepare_inputs_for_generation, model))
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setattr(model, '_prefix_lm_converted', True)
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return model
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def _convert_opt_causal_lm_to_prefix_lm(model: OPTForCausalLM) -> OPTForCausalLM:
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"""Converts an OPT Causal LM to a Prefix LM.
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See `convert_hf_causal_lm_to_prefix_lm` for more details.
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"""
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if hasattr(model, '_prefix_lm_converted'):
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return model
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assert isinstance(model, OPTForCausalLM)
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assert model.config.add_cross_attention == False, 'Only supports OPT decoder-only models'
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setattr(model, '_original_forward', getattr(model, 'forward'))
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setattr(model, '_original_generate', getattr(model, 'generate'))
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model.model.decoder.bidirectional_mask = None
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def _prepare_decoder_attention_mask(self: torch.nn.Module, attention_mask: Optional[torch.Tensor], input_shape: Tuple[int, int], inputs_embeds: Optional[torch.Tensor], past_key_values_length: int):
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combined_attention_mask = None
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if input_shape[-1] > 1:
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assert inputs_embeds is not None
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if self.bidirectional_mask == 'g':
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(bsz, src_length) = input_shape
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combined_attention_mask = torch.zeros((bsz, 1, src_length, src_length + past_key_values_length), dtype=inputs_embeds.dtype, device=inputs_embeds.device)
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else:
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combined_attention_mask = _make_causal_mask_opt(input_shape, inputs_embeds.dtype, past_key_values_length=past_key_values_length).to(inputs_embeds.device)
|
296 |
-
if self.bidirectional_mask is not None:
|
297 |
-
assert attention_mask is not None
|
298 |
-
assert attention_mask.shape == self.bidirectional_mask.shape
|
299 |
-
expanded_bidirectional_mask = _expand_mask_opt(self.bidirectional_mask, inputs_embeds.dtype, tgt_len=input_shape[-1]).to(inputs_embeds.device)
|
300 |
-
combined_attention_mask = torch.maximum(expanded_bidirectional_mask, combined_attention_mask)
|
301 |
-
if attention_mask is not None:
|
302 |
-
assert inputs_embeds is not None
|
303 |
-
expanded_attn_mask = _expand_mask_opt(attention_mask, inputs_embeds.dtype, tgt_len=input_shape[-1]).to(inputs_embeds.device)
|
304 |
-
combined_attention_mask = expanded_attn_mask if combined_attention_mask is None else expanded_attn_mask + combined_attention_mask
|
305 |
-
return combined_attention_mask
|
306 |
-
setattr(model.model.decoder, '_prepare_decoder_attention_mask', MethodType(_prepare_decoder_attention_mask, model.model.decoder))
|
307 |
-
|
308 |
-
def forward(self: OPTForCausalLM, input_ids: Optional[torch.LongTensor]=None, attention_mask: Optional[torch.Tensor]=None, bidirectional_mask: Optional[torch.ByteTensor]=None, head_mask: Optional[torch.Tensor]=None, past_key_values: Optional[List[torch.FloatTensor]]=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, return_dict: Optional[bool]=None):
|
309 |
-
|
310 |
-
def call_og_forward():
|
311 |
-
return self._original_forward(input_ids=input_ids, attention_mask=attention_mask, head_mask=head_mask, past_key_values=past_key_values, inputs_embeds=inputs_embeds, labels=labels, use_cache=use_cache, output_attentions=output_attentions, output_hidden_states=output_hidden_states, return_dict=return_dict)
|
312 |
-
if bidirectional_mask is None:
|
313 |
-
return call_og_forward()
|
314 |
-
self.model.decoder.bidirectional_mask = bidirectional_mask
|
315 |
-
try:
|
316 |
-
outputs = call_og_forward()
|
317 |
-
except:
|
318 |
-
self.model.decoder.bidirectional_mask = None
|
319 |
-
raise
|
320 |
-
self.model.decoder.bidirectional_mask = None
|
321 |
-
return outputs
|
322 |
-
|
323 |
-
def generate(self: OPTForCausalLM, *args: tuple, **kwargs: Any):
|
324 |
-
"""Wraps original generate to enable PrefixLM-style attention."""
|
325 |
-
self.model.decoder.bidirectional_mask = 'g'
|
326 |
-
try:
|
327 |
-
output = self._original_generate(*args, **kwargs)
|
328 |
-
except:
|
329 |
-
self.model.decoder.bidirectional_mask = None
|
330 |
-
raise
|
331 |
-
self.model.decoder.bidirectional_mask = None
|
332 |
-
return output
|
333 |
-
setattr(model, 'forward', MethodType(forward, model))
|
334 |
-
setattr(model, 'generate', MethodType(generate, model))
|
335 |
-
setattr(model, '_prefix_lm_converted', True)
|
336 |
-
return model
|
337 |
-
_SUPPORTED_HF_MODELS = _SUPPORTED_GPT_MODELS + (BloomForCausalLM, OPTForCausalLM)
|
338 |
-
CAUSAL_LM_TYPES = Union[GPT2LMHeadModel, GPTJForCausalLM, GPTNeoForCausalLM, GPTNeoXForCausalLM, BloomForCausalLM, OPTForCausalLM]
|
339 |
|
340 |
def convert_hf_causal_lm_to_prefix_lm(model: CAUSAL_LM_TYPES) -> CAUSAL_LM_TYPES:
|
341 |
"""Converts a HuggingFace Causal LM to a Prefix LM.
|
@@ -345,8 +178,6 @@ def convert_hf_causal_lm_to_prefix_lm(model: CAUSAL_LM_TYPES) -> CAUSAL_LM_TYPES
|
|
345 |
- `GPTNeoForCausalLM`
|
346 |
- `GPTNeoXForCausalLM`
|
347 |
- `GPTJForCausalLM`
|
348 |
-
- `BloomForCausalLM`
|
349 |
-
- `OPTForCausalLM`
|
350 |
|
351 |
Conversion to a Prefix LM is done by modifying the `forward` method, and possibly also the
|
352 |
`generate` method and/or select underlying methods depending on the model class.
|
@@ -396,12 +227,13 @@ def convert_hf_causal_lm_to_prefix_lm(model: CAUSAL_LM_TYPES) -> CAUSAL_LM_TYPES
|
|
396 |
"""
|
397 |
if isinstance(model, _SUPPORTED_GPT_MODELS):
|
398 |
return _convert_gpt_causal_lm_to_prefix_lm(model)
|
399 |
-
elif isinstance(model, BloomForCausalLM):
|
400 |
-
return _convert_bloom_causal_lm_to_prefix_lm(model)
|
401 |
-
elif isinstance(model, OPTForCausalLM):
|
402 |
-
return _convert_opt_causal_lm_to_prefix_lm(model)
|
403 |
else:
|
404 |
-
raise TypeError(
|
|
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|
405 |
|
406 |
def add_bidirectional_mask_if_missing(batch: MutableMapping):
|
407 |
"""Attempts to add bidirectional_mask to batch if missing.
|
@@ -409,12 +241,16 @@ def add_bidirectional_mask_if_missing(batch: MutableMapping):
|
|
409 |
Raises:
|
410 |
KeyError if bidirectional_mask is missing and can't be inferred
|
411 |
"""
|
412 |
-
if
|
413 |
-
if batch.get(
|
414 |
-
batch[
|
415 |
-
for
|
416 |
-
batch[
|
417 |
-
elif
|
418 |
-
batch[
|
|
|
|
|
419 |
else:
|
420 |
-
raise KeyError(
|
|
|
|
|
|
6 |
Prefix LMs accepts a `bidirectional_mask` input in `forward`
|
7 |
and treat the input prompt as the prefix in `generate`.
|
8 |
"""
|
|
|
|
|
9 |
from types import MethodType
|
10 |
from typing import Any, List, MutableMapping, Optional, Tuple, Union
|
11 |
import torch
|
|
|
|
|
|
|
|
|
12 |
from transformers.models.gpt2.modeling_gpt2 import GPT2LMHeadModel
|
13 |
from transformers.models.gpt_neo.modeling_gpt_neo import GPTNeoForCausalLM
|
14 |
from transformers.models.gpt_neox.modeling_gpt_neox import GPTNeoXForCausalLM
|
15 |
from transformers.models.gptj.modeling_gptj import GPTJForCausalLM
|
16 |
+
|
17 |
+
_SUPPORTED_GPT_MODELS = (
|
18 |
+
GPT2LMHeadModel,
|
19 |
+
GPTJForCausalLM,
|
20 |
+
GPTNeoForCausalLM,
|
21 |
+
GPTNeoXForCausalLM,
|
22 |
+
)
|
23 |
+
CAUSAL_GPT_TYPES = Union[
|
24 |
+
GPT2LMHeadModel, GPTJForCausalLM, GPTNeoForCausalLM, GPTNeoXForCausalLM
|
25 |
+
]
|
26 |
+
|
27 |
|
28 |
def _convert_gpt_causal_lm_to_prefix_lm(model: CAUSAL_GPT_TYPES) -> CAUSAL_GPT_TYPES:
|
29 |
"""Converts a GPT-style Causal LM to a Prefix LM.
|
|
|
36 |
|
37 |
See `convert_hf_causal_lm_to_prefix_lm` for more details.
|
38 |
"""
|
39 |
+
if hasattr(model, "_prefix_lm_converted"):
|
40 |
return model
|
41 |
assert isinstance(model, _SUPPORTED_GPT_MODELS)
|
42 |
+
assert (
|
43 |
+
model.config.add_cross_attention == False
|
44 |
+
), "Only supports GPT-style decoder-only models"
|
45 |
|
46 |
def _get_attn_modules(model: CAUSAL_GPT_TYPES) -> List[torch.nn.Module]:
|
47 |
"""Helper that gets a list of the model's attention modules.
|
|
|
57 |
blocks = model.transformer.h
|
58 |
for block in blocks:
|
59 |
if isinstance(model, GPTNeoForCausalLM):
|
60 |
+
if block.attn.attention_type != "global":
|
61 |
continue
|
62 |
attn_module = block.attn.attention
|
63 |
elif isinstance(model, GPTNeoXForCausalLM):
|
|
|
66 |
attn_module = block.attn
|
67 |
attn_modules.append(attn_module)
|
68 |
return attn_modules
|
|
|
|
|
69 |
|
70 |
+
setattr(model, "_original_forward", getattr(model, "forward"))
|
71 |
+
setattr(model, "_original_generate", getattr(model, "generate"))
|
72 |
+
|
73 |
+
def forward(
|
74 |
+
self: CAUSAL_GPT_TYPES,
|
75 |
+
input_ids: Optional[torch.LongTensor] = None,
|
76 |
+
past_key_values: Optional[Tuple[Tuple[torch.Tensor]]] = None,
|
77 |
+
attention_mask: Optional[torch.FloatTensor] = None,
|
78 |
+
bidirectional_mask: Optional[torch.Tensor] = None,
|
79 |
+
token_type_ids: Optional[torch.LongTensor] = None,
|
80 |
+
position_ids: Optional[torch.LongTensor] = None,
|
81 |
+
head_mask: Optional[torch.FloatTensor] = None,
|
82 |
+
inputs_embeds: Optional[torch.FloatTensor] = None,
|
83 |
+
labels: Optional[torch.LongTensor] = None,
|
84 |
+
use_cache: Optional[bool] = None,
|
85 |
+
output_attentions: Optional[bool] = None,
|
86 |
+
output_hidden_states: Optional[bool] = None,
|
87 |
+
return_dict: Optional[bool] = None,
|
88 |
+
):
|
89 |
"""Wraps original forward to enable PrefixLM attention."""
|
90 |
|
91 |
def call_og_forward():
|
92 |
if isinstance(self, GPTNeoXForCausalLM):
|
93 |
+
return self._original_forward(
|
94 |
+
input_ids=input_ids,
|
95 |
+
past_key_values=past_key_values,
|
96 |
+
attention_mask=attention_mask,
|
97 |
+
head_mask=head_mask,
|
98 |
+
inputs_embeds=inputs_embeds,
|
99 |
+
labels=labels,
|
100 |
+
use_cache=use_cache,
|
101 |
+
output_attentions=output_attentions,
|
102 |
+
output_hidden_states=output_hidden_states,
|
103 |
+
return_dict=return_dict,
|
104 |
+
)
|
105 |
else:
|
106 |
+
return self._original_forward(
|
107 |
+
input_ids=input_ids,
|
108 |
+
past_key_values=past_key_values,
|
109 |
+
attention_mask=attention_mask,
|
110 |
+
token_type_ids=token_type_ids,
|
111 |
+
position_ids=position_ids,
|
112 |
+
head_mask=head_mask,
|
113 |
+
inputs_embeds=inputs_embeds,
|
114 |
+
labels=labels,
|
115 |
+
use_cache=use_cache,
|
116 |
+
output_attentions=output_attentions,
|
117 |
+
output_hidden_states=output_hidden_states,
|
118 |
+
return_dict=return_dict,
|
119 |
+
)
|
120 |
+
|
121 |
if bidirectional_mask is None:
|
122 |
return call_og_forward()
|
123 |
assert isinstance(bidirectional_mask, torch.Tensor)
|
|
|
125 |
(b, s) = bidirectional_mask.shape
|
126 |
max_length = attn_modules[0].bias.shape[-1]
|
127 |
if s > max_length:
|
128 |
+
raise ValueError(
|
129 |
+
f"bidirectional_mask sequence length (={s}) exceeds the "
|
130 |
+
+ f"max length allowed by the model ({max_length})."
|
131 |
+
)
|
132 |
assert s <= max_length
|
133 |
if s < max_length:
|
134 |
+
pad = torch.zeros(
|
135 |
+
(int(b), int(max_length - s)),
|
136 |
+
dtype=bidirectional_mask.dtype,
|
137 |
+
device=bidirectional_mask.device,
|
138 |
+
)
|
139 |
bidirectional_mask = torch.cat([bidirectional_mask, pad], dim=1)
|
140 |
bidirectional = bidirectional_mask.unsqueeze(1).unsqueeze(1)
|
141 |
for attn_module in attn_modules:
|
142 |
assert isinstance(attn_module.bias, torch.Tensor)
|
143 |
+
attn_module.bias.data = torch.logical_or(
|
144 |
+
attn_module.bias.data, bidirectional
|
145 |
+
)
|
146 |
output = call_og_forward()
|
147 |
for attn_module in attn_modules:
|
148 |
attn_module.bias.data = torch.tril(attn_module.bias.data[0, 0])[None, None]
|
|
|
157 |
for attn_module in attn_modules:
|
158 |
attn_module.bias.data = torch.tril(attn_module.bias.data[0, 0])[None, None]
|
159 |
return output
|
|
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|
|
|
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|
|
|
|
|
|
|
|
|
|
|
|
|
160 |
|
161 |
+
setattr(model, "forward", MethodType(forward, model))
|
162 |
+
setattr(model, "generate", MethodType(generate, model))
|
163 |
+
setattr(model, "_prefix_lm_converted", True)
|
|
|
|
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|
164 |
return model
|
165 |
|
|
|
|
|
166 |
|
167 |
+
_SUPPORTED_HF_MODELS = _SUPPORTED_GPT_MODELS
|
168 |
+
CAUSAL_LM_TYPES = Union[
|
169 |
+
GPT2LMHeadModel, GPTJForCausalLM, GPTNeoForCausalLM, GPTNeoXForCausalLM
|
170 |
+
]
|
171 |
|
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|
172 |
|
173 |
def convert_hf_causal_lm_to_prefix_lm(model: CAUSAL_LM_TYPES) -> CAUSAL_LM_TYPES:
|
174 |
"""Converts a HuggingFace Causal LM to a Prefix LM.
|
|
|
178 |
- `GPTNeoForCausalLM`
|
179 |
- `GPTNeoXForCausalLM`
|
180 |
- `GPTJForCausalLM`
|
|
|
|
|
181 |
|
182 |
Conversion to a Prefix LM is done by modifying the `forward` method, and possibly also the
|
183 |
`generate` method and/or select underlying methods depending on the model class.
|
|
|
227 |
"""
|
228 |
if isinstance(model, _SUPPORTED_GPT_MODELS):
|
229 |
return _convert_gpt_causal_lm_to_prefix_lm(model)
|
|
|
|
|
|
|
|
|
230 |
else:
|
231 |
+
raise TypeError(
|
232 |
+
f"Cannot convert model to Prefix LM. "
|
233 |
+
+ f"Model does not belong to set of supported HF models:"
|
234 |
+
+ f"\n{_SUPPORTED_HF_MODELS}"
|
235 |
+
)
|
236 |
+
|
237 |
|
238 |
def add_bidirectional_mask_if_missing(batch: MutableMapping):
|
239 |
"""Attempts to add bidirectional_mask to batch if missing.
|
|
|
241 |
Raises:
|
242 |
KeyError if bidirectional_mask is missing and can't be inferred
|
243 |
"""
|
244 |
+
if "bidirectional_mask" not in batch:
|
245 |
+
if batch.get("mode", None) == "icl_task":
|
246 |
+
batch["bidirectional_mask"] = batch["attention_mask"].clone()
|
247 |
+
for i, continuation_indices in enumerate(batch["continuation_indices"]):
|
248 |
+
batch["bidirectional_mask"][i, continuation_indices] = 0
|
249 |
+
elif "labels" in batch and "attention_mask" in batch:
|
250 |
+
batch["bidirectional_mask"] = torch.logical_and(
|
251 |
+
torch.eq(batch["attention_mask"], 1), torch.eq(batch["labels"], -100)
|
252 |
+
).type_as(batch["attention_mask"])
|
253 |
else:
|
254 |
+
raise KeyError(
|
255 |
+
"No bidirectional_mask in batch and not sure how to construct one."
|
256 |
+
)
|