# Copyright 2024 The HuggingFace Team. All rights reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. import math from typing import Optional, Tuple from transformers.configuration_utils import PretrainedConfig from transformers.utils import is_torch_available, logging logger = logging.get_logger(__name__) if is_torch_available(): import torch def _compute_default_rope_parameters( config: Optional[PretrainedConfig] = None, device: Optional["torch.device"] = None, seq_len: Optional[int] = None, **rope_kwargs, ) -> Tuple["torch.Tensor", float]: """ Computes the inverse frequencies according to the original RoPE implementation Args: config ([`~transformers.PretrainedConfig`]): The model configuration. device (`torch.device`): The device to use for initialization of the inverse frequencies. seq_len (`int`, *optional*): The current sequence length. Unused for this type of RoPE. rope_kwargs (`Dict`, *optional*): BC compatibility with the previous RoPE class instantiation, will be removed in v4.45. Returns: Tuple of (`torch.Tensor`, `float`), containing the inverse frequencies for the RoPE embeddings and the post-processing scaling factor applied to the computed cos/sin (unused in this type of RoPE). """ if config is not None and len(rope_kwargs) > 0: raise ValueError( "Unexpected arguments: `**rope_kwargs` and `config` are mutually exclusive in " f"`_compute_default_rope_parameters`, got `rope_kwargs`={rope_kwargs} and `config`={config}" ) if len(rope_kwargs) > 0: base = rope_kwargs["base"] dim = rope_kwargs["dim"] elif config is not None: base = config.rope_theta partial_rotary_factor = config.partial_rotary_factor if hasattr(config, "partial_rotary_factor") else 1.0 head_dim = getattr(config, "head_dim", config.hidden_size // config.num_attention_heads) dim = int(head_dim * partial_rotary_factor) attention_factor = 1.0 # Unused in this type of RoPE # Compute the inverse frequencies inv_freq = 1.0 / (base ** (torch.arange(0, dim, 2, dtype=torch.int64).float().to(device) / dim)) return inv_freq, attention_factor def _compute_linear_scaling_rope_parameters( config: Optional[PretrainedConfig] = None, device: Optional["torch.device"] = None, seq_len: Optional[int] = None, **rope_kwargs, ) -> Tuple["torch.Tensor", float]: """ Computes the inverse frequencies with linear scaling. Credits to the Reddit user /u/kaiokendev Args: config ([`~transformers.PretrainedConfig`]): The model configuration. device (`torch.device`): The device to use for initialization of the inverse frequencies. seq_len (`int`, *optional*): The current sequence length. Unused for this type of RoPE. rope_kwargs (`Dict`, *optional*): BC compatibility with the previous RoPE class instantiation, will be removed in v4.45. Returns: Tuple of (`torch.Tensor`, `float`), containing the inverse frequencies for the RoPE embeddings and the post-processing scaling factor applied to the computed cos/sin (unused in this type of RoPE). """ if config is not None and len(rope_kwargs) > 0: raise ValueError( "Unexpected arguments: `**rope_kwargs` and `config` are mutually exclusive in " f"`_compute_linear_scaling_rope_parameters`, got `rope_kwargs`={rope_kwargs} and `config`={config}" ) if len(rope_kwargs) > 0: factor = rope_kwargs["factor"] elif config is not None: factor = config.rope_scaling["factor"] # Gets the default RoPE parameters inv_freq, attention_factor = _compute_default_rope_parameters(config, device, seq_len, **rope_kwargs) # Then applies linear scaling to the frequencies. # NOTE: originally, scaling was applied to the position_ids. However, we get `embs = inv_freq @ position_ids`, so # applying scaling to the inverse frequencies is equivalent. inv_freq /= factor return inv_freq, attention_factor def _compute_dynamic_ntk_parameters( config: Optional[PretrainedConfig] = None, device: Optional["torch.device"] = None, seq_len: Optional[int] = None, **rope_kwargs, ) -> Tuple["torch.Tensor", float]: """ Computes the inverse frequencies with NTK scaling. Credits to the Reddit users /u/bloc97 and /u/emozilla Args: config ([`~transformers.PretrainedConfig`]): The model configuration. device (`torch.device`): The device to use for initialization of the inverse frequencies. seq_len (`int`, *optional*): The current sequence length, used to update the dynamic RoPE at inference time. rope_kwargs (`Dict`, *optional*): BC compatibility with the previous RoPE class instantiation, will be removed in v4.45. Returns: Tuple of (`torch.Tensor`, `float`), containing the inverse frequencies for the RoPE embeddings and the post-processing scaling factor applied to the computed cos/sin (unused in this type of RoPE). """ # TODO (joao): use the new `original_max_position_embeddings` from rope_scaling if config is not None and len(rope_kwargs) > 0: raise ValueError( "Unexpected arguments: `**rope_kwargs` and `config` are mutually exclusive in " f"`_compute_dynamic_ntk_parameters`, got `rope_kwargs`={rope_kwargs} and `config`={config}" ) if len(rope_kwargs) > 0: base = rope_kwargs["base"] dim = rope_kwargs["dim"] max_position_embeddings = rope_kwargs["max_position_embeddings"] factor = rope_kwargs["factor"] elif config is not None: base = config.rope_theta partial_rotary_factor = config.partial_rotary_factor if hasattr(config, "partial_rotary_factor") else 1.0 head_dim = getattr(config, "head_dim", config.hidden_size // config.num_attention_heads) dim = int(head_dim * partial_rotary_factor) max_position_embeddings = config.max_position_embeddings factor = config.rope_scaling["factor"] attention_factor = 1.0 # Unused in this type of RoPE # seq_len: default to max_position_embeddings, e.g. at init time seq_len = seq_len if seq_len is not None and seq_len > max_position_embeddings else max_position_embeddings # Compute the inverse frequencies base = base * ((factor * seq_len / max_position_embeddings) - (factor - 1)) ** (dim / (dim - 2)) inv_freq = 1.0 / (base ** (torch.arange(0, dim, 2, dtype=torch.int64).float().to(device) / dim)) return inv_freq, attention_factor def _compute_yarn_parameters( config: PretrainedConfig, device: "torch.device", seq_len: Optional[int] = None, **rope_kwargs ) -> Tuple["torch.Tensor", float]: """ Computes the inverse frequencies with NTK scaling. Please refer to the [original paper](https://arxiv.org/abs/2309.00071) Args: config ([`~transformers.PretrainedConfig`]): The model configuration. device (`torch.device`): The device to use for initialization of the inverse frequencies. seq_len (`int`, *optional*): The current sequence length. Unused for this type of RoPE. rope_kwargs (`Dict`, *optional*): BC compatibility with the previous RoPE class instantiation, will be removed in v4.45. Returns: Tuple of (`torch.Tensor`, `float`), containing the inverse frequencies for the RoPE embeddings and the post-processing scaling factor applied to the computed cos/sin. """ # No need to keep BC with yarn, unreleased when this new pattern was created. if len(rope_kwargs) > 0: raise ValueError( f"Unexpected arguments: `**rope_kwargs` should be unset in `_compute_yarn_parameters`, got {rope_kwargs}" ) base = config.rope_theta partial_rotary_factor = config.partial_rotary_factor if hasattr(config, "partial_rotary_factor") else 1.0 head_dim = getattr(config, "head_dim", config.hidden_size // config.num_attention_heads) dim = int(head_dim * partial_rotary_factor) max_position_embeddings = config.max_position_embeddings factor = config.rope_scaling["factor"] # Sets the attention factor as suggested in the paper attention_factor = config.rope_scaling.get("attention_factor") if attention_factor is None: attention_factor = 0.1 * math.log(factor) + 1.0 # Optional config options # beta_fast/beta_slow: as suggested in the paper, default to 32/1 (correspondingly) beta_fast = config.rope_scaling.get("beta_fast") or 32 beta_slow = config.rope_scaling.get("beta_slow") or 1 # Compute the inverse frequencies def find_correction_dim(num_rotations, dim, base, max_position_embeddings): """Inverse dimension formula to find the dimension based on the number of rotations""" return (dim * math.log(max_position_embeddings / (num_rotations * 2 * math.pi))) / (2 * math.log(base)) def find_correction_range(low_rot, high_rot, dim, base, max_position_embeddings): """Find dimension range bounds based on rotations""" low = math.floor(find_correction_dim(low_rot, dim, base, max_position_embeddings)) high = math.ceil(find_correction_dim(high_rot, dim, base, max_position_embeddings)) return max(low, 0), min(high, dim - 1) def linear_ramp_factor(min, max, dim): if min == max: max += 0.001 # Prevent singularity linear_func = (torch.arange(dim, dtype=torch.float32) - min) / (max - min) ramp_func = torch.clamp(linear_func, 0, 1) return ramp_func # Note on variable naming: "interpolation" comes from the original technique, where we interpolate the position IDs # to expand the possible context length. In other words, interpolation = apply scaling factor. pos_freqs = base ** (torch.arange(0, dim, 2).float().to(device) / dim) inv_freq_extrapolation = 1.0 / pos_freqs inv_freq_interpolation = 1.0 / (factor * pos_freqs) low, high = find_correction_range(beta_fast, beta_slow, dim, base, max_position_embeddings) # Get n-dimensional rotational scaling corrected for extrapolation inv_freq_extrapolation_factor = 1 - linear_ramp_factor(low, high, dim // 2).float().to(device) inv_freq = ( inv_freq_interpolation * (1 - inv_freq_extrapolation_factor) + inv_freq_extrapolation * inv_freq_extrapolation_factor ) return inv_freq, attention_factor def _compute_longrope_parameters( config: PretrainedConfig, device: "torch.device", seq_len: Optional[int] = None, **rope_kwargs ) -> Tuple["torch.Tensor", float]: """ Computes the inverse frequencies with LongRoPE scaling. Please refer to the [original implementation](https://github.com/microsoft/LongRoPE) Args: config ([`~transformers.PretrainedConfig`]): The model configuration. device (`torch.device`): The device to use for initialization of the inverse frequencies. seq_len (`int`, *optional*): The current sequence length. Unused for this type of RoPE. rope_kwargs (`Dict`, *optional*): BC compatibility with the previous RoPE class instantiation, will be removed in v4.45. Returns: Tuple of (`torch.Tensor`, `float`), containing the inverse frequencies for the RoPE embeddings and the post-processing scaling factor applied to the computed cos/sin. """ # TODO (joao): use the new `original_max_position_embeddings` from rope_scaling # No need to keep BC with longrope, unreleased when this new pattern was created. if len(rope_kwargs) > 0: raise ValueError( "Unexpected arguments: `**rope_kwargs` should be unset in `_compute_longrope_parameters`, got " f"{rope_kwargs}" ) base = config.rope_theta partial_rotary_factor = config.partial_rotary_factor if hasattr(config, "partial_rotary_factor") else 1.0 head_dim = getattr(config, "head_dim", config.hidden_size // config.num_attention_heads) dim = int(head_dim * partial_rotary_factor) long_factor = config.rope_scaling["long_factor"] short_factor = config.rope_scaling["short_factor"] factor = config.rope_scaling.get("factor") attention_factor = config.rope_scaling.get("attention_factor") # NOTE: Phi3 (and potentially other models) modify `max_position_embeddings` and have a # `original_max_position_embeddings` field containing the pretrained value. They use the ratio between these two # values to compute the default attention scaling factor, instead of using `factor`. if hasattr(config, "original_max_position_embeddings"): max_position_embeddings = config.original_max_position_embeddings expanded_max_position_embeddings = config.max_position_embeddings factor = expanded_max_position_embeddings / max_position_embeddings else: max_position_embeddings = config.max_position_embeddings expanded_max_position_embeddings = max_position_embeddings * factor # Sets the attention factor as suggested in the paper if attention_factor is None: if factor <= 1.0: attention_factor = 1.0 else: attention_factor = math.sqrt(1 + math.log(factor) / math.log(max_position_embeddings)) # Compute the inverse frequencies -- scaled based on the target sequence length if expanded_max_position_embeddings > max_position_embeddings: ext_factors = torch.tensor(long_factor, dtype=torch.float32, device=device) else: ext_factors = torch.tensor(short_factor, dtype=torch.float32, device=device) inv_freq_shape = torch.arange(0, dim, 2, dtype=torch.int64, device=device).float() / dim inv_freq = 1.0 / (ext_factors * base**inv_freq_shape) return inv_freq, attention_factor def _compute_llama3_parameters( config: PretrainedConfig, device: "torch.device", seq_len: Optional[int] = None, **rope_kwargs ) -> Tuple["torch.Tensor", float]: """ Computes the inverse frequencies for llama 3.1. Args: config ([`~transformers.PretrainedConfig`]): The model configuration. device (`torch.device`): The device to use for initialization of the inverse frequencies. seq_len (`int`, *optional*): The current sequence length. Unused for this type of RoPE. rope_kwargs (`Dict`, *optional*): BC compatibility with the previous RoPE class instantiation, will be removed in v4.45. Returns: Tuple of (`torch.Tensor`, `float`), containing the inverse frequencies for the RoPE embeddings and the post-processing scaling factor applied to the computed cos/sin. """ # Gets the default RoPE parameters inv_freq, attention_factor = _compute_default_rope_parameters(config, device, seq_len, **rope_kwargs) factor = config.rope_scaling["factor"] # `8` in the original implementation low_freq_factor = config.rope_scaling["low_freq_factor"] # `1` in the original implementation high_freq_factor = config.rope_scaling["high_freq_factor"] # `4` in the original implementation old_context_len = config.rope_scaling["original_max_position_embeddings"] # `8192` in the original implementation low_freq_wavelen = old_context_len / low_freq_factor high_freq_wavelen = old_context_len / high_freq_factor wavelen = 2 * math.pi / inv_freq # wavelen < high_freq_wavelen: do nothing # wavelen > low_freq_wavelen: divide by factor inv_freq_llama = torch.where(wavelen > low_freq_wavelen, inv_freq / factor, inv_freq) # otherwise: interpolate between the two, using a smooth factor smooth_factor = (old_context_len / wavelen - low_freq_factor) / (high_freq_factor - low_freq_factor) smoothed_inv_freq = (1 - smooth_factor) * inv_freq_llama / factor + smooth_factor * inv_freq_llama is_medium_freq = ~(wavelen < high_freq_wavelen) * ~(wavelen > low_freq_wavelen) inv_freq_llama = torch.where(is_medium_freq, smoothed_inv_freq, inv_freq_llama) return inv_freq_llama, attention_factor # This maps the "rope_type" string field in rope config to the corresponding function to compute the RoPE parameters # from the model config. You can append new {'rope_type': callable} pairs to this dictionary to enable custom RoPE # parameterizations, as long as the callable has the same signature. ROPE_INIT_FUNCTIONS = { "default": _compute_default_rope_parameters, "linear": _compute_linear_scaling_rope_parameters, "dynamic": _compute_dynamic_ntk_parameters, "yarn": _compute_yarn_parameters, "longrope": _compute_longrope_parameters, "llama3": _compute_llama3_parameters, } def _check_received_keys(rope_type: str, received_keys: set, required_keys: set, optional_keys: Optional[set] = None): """Compare the received keys in `config.rope_scaling` against the expected and optional keys""" # BC: "rope_type" was originally "type" -- let's gracefully handle it if "rope_type" not in received_keys and "type" in received_keys: received_keys -= {"type"} received_keys.add("rope_type") missing_keys = required_keys - received_keys if missing_keys: raise KeyError(f"Missing required keys in `rope_scaling` for 'rope_type'='{rope_type}': {missing_keys}") if optional_keys is not None: unused_keys = received_keys - required_keys - optional_keys else: unused_keys = received_keys - required_keys if unused_keys: logger.warning(f"Unrecognized keys in `rope_scaling` for 'rope_type'='{rope_type}': {unused_keys}") def _validate_default_rope_parameters(config: PretrainedConfig): rope_scaling = config.rope_scaling rope_type = rope_scaling.get("rope_type", rope_scaling.get("type", None)) # BC: "rope_type" was originally "type" required_keys = {"rope_type"} received_keys = set(rope_scaling.keys()) _check_received_keys(rope_type, received_keys, required_keys) def _validate_linear_scaling_rope_parameters(config: PretrainedConfig): rope_scaling = config.rope_scaling rope_type = rope_scaling.get("rope_type", rope_scaling.get("type", None)) # BC: "rope_type" was originally "type" required_keys = {"rope_type", "factor"} received_keys = set(rope_scaling.keys()) _check_received_keys(rope_type, received_keys, required_keys) factor = rope_scaling["factor"] if factor is None or not isinstance(factor, float) or factor < 1.0: logger.warning(f"`rope_scaling`'s factor field must be a float >= 1, got {factor}") def _validate_dynamic_scaling_rope_parameters(config: PretrainedConfig): rope_scaling = config.rope_scaling rope_type = rope_scaling.get("rope_type", rope_scaling.get("type", None)) # BC: "rope_type" was originally "type" required_keys = {"rope_type", "factor"} # TODO (joao): update logic for the inclusion of `original_max_position_embeddings` optional_keys = {"original_max_position_embeddings"} received_keys = set(rope_scaling.keys()) _check_received_keys(rope_type, received_keys, required_keys, optional_keys) factor = rope_scaling["factor"] if factor is None or not isinstance(factor, float) or factor < 1.0: logger.warning(f"`rope_scaling`'s factor field must be a float >= 1, got {factor}") def _validate_yarn_parameters(config: PretrainedConfig): rope_scaling = config.rope_scaling rope_type = rope_scaling.get("rope_type", rope_scaling.get("type", None)) # BC: "rope_type" was originally "type" required_keys = {"rope_type", "factor"} optional_keys = {"attention_factor", "beta_fast", "beta_slow"} received_keys = set(rope_scaling.keys()) _check_received_keys(rope_type, received_keys, required_keys, optional_keys) factor = rope_scaling["factor"] if factor is None or not isinstance(factor, float) or factor < 1.0: logger.warning(f"`rope_scaling`'s factor field must be a float >= 1, got {factor}") attention_factor = rope_scaling.get("attention_factor") if attention_factor is not None and (not isinstance(attention_factor, float) or attention_factor < 0): logger.warning( f"`rope_scaling`'s attention_factor field must be a float greater than 0, got {attention_factor}" ) beta_fast = rope_scaling.get("beta_fast") if beta_fast is not None and not isinstance(beta_fast, float): logger.warning(f"`rope_scaling`'s beta_fast field must be a float, got {beta_fast}") beta_slow = rope_scaling.get("beta_slow") if beta_slow is not None and not isinstance(beta_slow, float): logger.warning(f"`rope_scaling`'s beta_slow field must be a float, got {beta_slow}") if (beta_fast or 32) < (beta_slow or 1): logger.warning( f"`rope_scaling`'s beta_fast field must be greater than beta_slow, got beta_fast={beta_fast} " f"(defaults to 32 if None) and beta_slow={beta_slow} (defaults to 1 if None)" ) def _validate_longrope_parameters(config: PretrainedConfig): rope_scaling = config.rope_scaling rope_type = rope_scaling.get("rope_type", rope_scaling.get("type", None)) # BC: "rope_type" was originally "type" required_keys = {"rope_type", "short_factor", "long_factor"} # TODO (joao): update logic for the inclusion of `original_max_position_embeddings` optional_keys = {"attention_factor", "factor", "original_max_position_embeddings"} received_keys = set(rope_scaling.keys()) _check_received_keys(rope_type, received_keys, required_keys, optional_keys) partial_rotary_factor = config.partial_rotary_factor if hasattr(config, "partial_rotary_factor") else 1.0 head_dim = getattr(config, "head_dim", config.hidden_size // config.num_attention_heads) dim = int(head_dim * partial_rotary_factor) short_factor = rope_scaling.get("short_factor") if not isinstance(short_factor, list) and all(isinstance(x, (int, float)) for x in short_factor): logger.warning(f"`rope_scaling`'s short_factor field must be a list of numbers, got {short_factor}") if not len(short_factor) == dim // 2: logger.warning(f"`rope_scaling`'s short_factor field must have length {dim // 2}, got {len(short_factor)}") long_factor = rope_scaling.get("long_factor") if not isinstance(long_factor, list) and all(isinstance(x, (int, float)) for x in long_factor): logger.warning(f"`rope_scaling`'s long_factor field must be a list of numbers, got {long_factor}") if not len(long_factor) == dim // 2: logger.warning(f"`rope_scaling`'s long_factor field must have length {dim // 2}, got {len(long_factor)}") # Handle Phi3 divergence: prefer the use of `attention_factor` and/or `factor` over # `original_max_position_embeddings` to compute internal variables. The latter lives outside `rope_scaling` and is # unique to longrope (= undesirable) if hasattr(config, "original_max_position_embeddings"): logger.warning_once( "This model has set a `original_max_position_embeddings` field, to be used together with " "`max_position_embeddings` to determine a scaling factor. Please set the `factor` field of `rope_scaling`" "with this ratio instead -- we recommend the use of this field over `original_max_position_embeddings`, " "as it is compatible with most model architectures." ) else: factor = rope_scaling.get("factor") if factor is None: logger.warning("Missing required keys in `rope_scaling`: 'factor'") elif not isinstance(factor, float) or factor < 1.0: logger.warning(f"`rope_scaling`'s factor field must be a float >= 1, got {factor}") attention_factor = rope_scaling.get("attention_factor") if attention_factor is not None and not isinstance(attention_factor, float) or attention_factor < 0: logger.warning( f"`rope_scaling`'s attention_factor field must be a float greater than 0, got {attention_factor}" ) def _validate_llama3_parameters(config: PretrainedConfig): rope_scaling = config.rope_scaling rope_type = rope_scaling.get("rope_type", rope_scaling.get("type", None)) # BC: "rope_type" was originally "type" required_keys = {"rope_type", "factor", "original_max_position_embeddings", "low_freq_factor", "high_freq_factor"} received_keys = set(rope_scaling.keys()) _check_received_keys(rope_type, received_keys, required_keys) factor = rope_scaling["factor"] if factor is None or not isinstance(factor, float) or factor < 1.0: logger.warning(f"`rope_scaling`'s factor field must be a float >= 1, got {factor}") low_freq_factor = rope_scaling["low_freq_factor"] high_freq_factor = rope_scaling["high_freq_factor"] if low_freq_factor is None or not isinstance(low_freq_factor, float): logger.warning(f"`rope_scaling`'s low_freq_factor field must be a float, got {low_freq_factor}") if high_freq_factor is None or not isinstance(high_freq_factor, float): logger.warning(f"`rope_scaling`'s high_freq_factor field must be a float, got {high_freq_factor}") if high_freq_factor <= low_freq_factor: logger.warning( "`rope_scaling`'s high_freq_factor field must be greater than low_freq_factor, got high_freq_factor=" f"{high_freq_factor} and low_freq_factor={low_freq_factor}" ) original_max_position_embeddings = rope_scaling["original_max_position_embeddings"] if original_max_position_embeddings is None or not isinstance(original_max_position_embeddings, int): logger.warning( "`rope_scaling`'s original_max_position_embeddings field must be an integer, got " f"{original_max_position_embeddings}" ) if original_max_position_embeddings >= config.max_position_embeddings: logger.warning( "`rope_scaling`'s original_max_position_embeddings field must be less than max_position_embeddings, got " f"{original_max_position_embeddings} and max_position_embeddings={config.max_position_embeddings}" ) # Like `ROPE_INIT_FUNCTIONS`, this validation function mapping can be dynamically updated for custom RoPE types. ROPE_VALIDATION_FUNCTIONS = { "default": _validate_default_rope_parameters, "linear": _validate_linear_scaling_rope_parameters, "dynamic": _validate_dynamic_scaling_rope_parameters, "yarn": _validate_yarn_parameters, "longrope": _validate_longrope_parameters, "llama3": _validate_llama3_parameters, } def rope_config_validation(config: PretrainedConfig): """ Validate the RoPE config arguments, given a `PretrainedConfig` object """ rope_scaling = getattr(config, "rope_scaling", None) # not a default parameter in `PretrainedConfig` if rope_scaling is None: return # BC: "rope_type" was originally "type" rope_type = rope_scaling.get("rope_type", rope_scaling.get("type", "default")) validation_fn = ROPE_VALIDATION_FUNCTIONS.get(rope_type) if validation_fn is not None: validation_fn(config) else: logger.warning( f"Missing validation function mapping in `ROPE_VALIDATION_FUNCTIONS` for 'rope_type'='{rope_type}'" )