Files
vLLM/vllm/model_executor/layers/rotary_embedding.py
T
Russell Bryant e489ad7a21 [Misc] Add SPDX-License-Identifier headers to python source files (#12628)
- **Add SPDX license headers to python source files**
- **Check for SPDX headers using pre-commit**

commit 9d7ef44c3cfb72ca4c32e1c677d99259d10d4745
Author: Russell Bryant <rbryant@redhat.com>
Date:   Fri Jan 31 14:18:24 2025 -0500

    Add SPDX license headers to python source files
    
This commit adds SPDX license headers to python source files as
recommended to
the project by the Linux Foundation. These headers provide a concise way
that is
both human and machine readable for communicating license information
for each
source file. It helps avoid any ambiguity about the license of the code
and can
    also be easily used by tools to help manage license compliance.
    
The Linux Foundation runs license scans against the codebase to help
ensure
    we are in compliance with the licenses of the code we use, including
dependencies. Having these headers in place helps that tool do its job.
    
    More information can be found on the SPDX site:
    
    - https://spdx.dev/learn/handling-license-info/
    
    Signed-off-by: Russell Bryant <rbryant@redhat.com>

commit 5a1cf1cb3b80759131c73f6a9dddebccac039dea
Author: Russell Bryant <rbryant@redhat.com>
Date:   Fri Jan 31 14:36:32 2025 -0500

    Check for SPDX headers using pre-commit
    
    Signed-off-by: Russell Bryant <rbryant@redhat.com>

---------

Signed-off-by: Russell Bryant <rbryant@redhat.com>
2025-02-02 11:58:18 -08:00

1105 lines
42 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# Adapted from
# https://github.com/huggingface/transformers/blob/v4.33.2/src/transformers/models/llama/modeling_llama.py
# Copyright 2023 The vLLM team.
# Copyright 2022 EleutherAI and the HuggingFace Inc. team. All rights reserved.
#
# This code is based on EleutherAI's GPT-NeoX library and the GPT-NeoX
# and OPT implementations in this library. It has been modified from its
# original forms to accommodate minor architectural differences compared
# to GPT-NeoX and OPT used by the Meta AI team that trained the model.
#
# 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.
"""Rotary Positional Embeddings."""
import math
from typing import Any, Dict, List, Optional, Tuple, Union
import torch
import torch.nn as nn
from vllm.model_executor.custom_op import CustomOp
def _rotate_neox(x: torch.Tensor) -> torch.Tensor:
x1 = x[..., :x.shape[-1] // 2]
x2 = x[..., x.shape[-1] // 2:]
return torch.cat((-x2, x1), dim=-1)
def _rotate_gptj(x: torch.Tensor) -> torch.Tensor:
x1 = x[..., ::2]
x2 = x[..., 1::2]
x = torch.stack((-x2, x1), dim=-1)
return x.flatten(-2)
def _apply_rotary_emb(
x: torch.Tensor,
cos: torch.Tensor,
sin: torch.Tensor,
is_neox_style: bool,
) -> torch.Tensor:
"""
Args:
x: [num_tokens, num_heads, head_size]
cos: [num_tokens, head_size // 2]
sin: [num_tokens, head_size // 2]
is_neox_style: Whether to use the Neox-style or GPT-J-style rotary
positional embeddings.
"""
cos = cos.unsqueeze(-2).to(x.dtype)
sin = sin.unsqueeze(-2).to(x.dtype)
if is_neox_style:
x1, x2 = torch.chunk(x, 2, dim=-1)
else:
x1 = x[..., ::2]
x2 = x[..., 1::2]
o1 = x1 * cos - x2 * sin
o2 = x2 * cos + x1 * sin
if is_neox_style:
return torch.cat((o1, o2), dim=-1)
else:
return torch.stack((o1, o2), dim=-1).flatten(-2)
@CustomOp.register("rotary_embedding")
class RotaryEmbedding(CustomOp):
"""Original rotary positional embedding."""
def __init__(
self,
head_size: int,
rotary_dim: int,
max_position_embeddings: int,
base: int,
is_neox_style: bool,
dtype: torch.dtype,
) -> None:
super().__init__()
self.head_size = head_size
self.rotary_dim = rotary_dim
self.max_position_embeddings = max_position_embeddings
self.base = base
self.is_neox_style = is_neox_style
self.dtype = dtype
cache = self._compute_cos_sin_cache()
cache = cache.to(dtype)
self.cos_sin_cache: torch.Tensor
self.register_buffer("cos_sin_cache", cache, persistent=False)
def _compute_inv_freq(self, base: Union[int, float]) -> torch.Tensor:
"""Compute the inverse frequency."""
# NOTE(woosuk): To exactly match the HF implementation, we need to
# use CPU to compute the cache and then move it to GPU. However, we
# create the cache on GPU for faster initialization. This may cause
# a slight numerical difference between the HF implementation and ours.
inv_freq = 1.0 / (base**(torch.arange(
0, self.rotary_dim, 2, dtype=torch.float) / self.rotary_dim))
return inv_freq
def _compute_cos_sin_cache(self) -> torch.Tensor:
"""Compute the cos and sin cache."""
inv_freq = self._compute_inv_freq(self.base)
t = torch.arange(self.max_position_embeddings, dtype=torch.float)
freqs = torch.einsum("i,j -> ij", t, inv_freq)
cos = freqs.cos()
sin = freqs.sin()
cache = torch.cat((cos, sin), dim=-1)
return cache
def forward_native(
self,
positions: torch.Tensor,
query: torch.Tensor,
key: torch.Tensor,
offsets: Optional[torch.Tensor] = None,
) -> Tuple[torch.Tensor, torch.Tensor]:
"""A PyTorch-native implementation of forward()."""
if offsets is not None:
positions = positions + offsets
positions = positions.flatten()
num_tokens = positions.shape[0]
cos_sin = self.cos_sin_cache.index_select(0, positions)
cos, sin = cos_sin.chunk(2, dim=-1)
query_shape = query.shape
query = query.view(num_tokens, -1, self.head_size)
query_rot = query[..., :self.rotary_dim]
query_pass = query[..., self.rotary_dim:]
query_rot = _apply_rotary_emb(query_rot, cos, sin, self.is_neox_style)
query = torch.cat((query_rot, query_pass), dim=-1).reshape(query_shape)
key_shape = key.shape
key = key.view(num_tokens, -1, self.head_size)
key_rot = key[..., :self.rotary_dim]
key_pass = key[..., self.rotary_dim:]
key_rot = _apply_rotary_emb(key_rot, cos, sin, self.is_neox_style)
key = torch.cat((key_rot, key_pass), dim=-1).reshape(key_shape)
return query, key
def forward_cuda(
self,
positions: torch.Tensor,
query: torch.Tensor,
key: torch.Tensor,
offsets: Optional[torch.Tensor] = None,
) -> Tuple[torch.Tensor, torch.Tensor]:
from vllm import _custom_ops as ops
self.cos_sin_cache = self.cos_sin_cache.to(query.device,
dtype=query.dtype)
# ops.rotary_embedding()/batched_rotary_embedding()
# are in-place operations that update the query and key tensors.
if offsets is not None:
ops.batched_rotary_embedding(positions, query, key, self.head_size,
self.cos_sin_cache,
self.is_neox_style, self.rotary_dim,
offsets)
else:
ops.rotary_embedding(positions, query, key, self.head_size,
self.cos_sin_cache, self.is_neox_style)
return query, key
def forward_xpu(
self,
positions: torch.Tensor,
query: torch.Tensor,
key: torch.Tensor,
offsets: Optional[torch.Tensor] = None,
) -> Tuple[torch.Tensor, torch.Tensor]:
from vllm._ipex_ops import ipex_ops as ops
self.cos_sin_cache = self.cos_sin_cache.to(positions.device,
dtype=query.dtype)
# ops.rotary_embedding()/batched_rotary_embedding()
# are in-place operations that update the query and key tensors.
if offsets is not None:
ops.batched_rotary_embedding(positions, query, key, self.head_size,
self.cos_sin_cache,
self.is_neox_style, self.rotary_dim,
offsets)
else:
ops.rotary_embedding(positions, query, key, self.head_size,
self.cos_sin_cache, self.is_neox_style)
return query, key
def forward_hpu(
self,
positions: torch.Tensor,
query: torch.Tensor,
key: torch.Tensor,
offsets: Optional[torch.Tensor] = None,
) -> Tuple[torch.Tensor, torch.Tensor]:
from habana_frameworks.torch.hpex.kernels import (
RotaryPosEmbeddingMode, apply_rotary_pos_emb)
positions = positions.flatten()
if offsets is not None:
positions = positions + offsets
num_tokens = positions.shape[0]
cos_sin = self.cos_sin_cache.index_select(0, positions).view(
num_tokens, 1, -1)
cos, sin = cos_sin.chunk(2, dim=-1)
# HPU RoPE kernel requires hidden dimension for cos and sin to be equal
# to query hidden dimension, so the original tensors need to be
# expanded
# GPT-NeoX kernel requires position_ids = None, offset, mode = BLOCKWISE
# and expansion of cos/sin tensors via concatenation
# GPT-J kernel requires position_ids = None, offset = 0, mode = PAIRWISE
# and expansion of cos/sin tensors via repeat_interleave
rope_mode: RotaryPosEmbeddingMode
if self.is_neox_style:
rope_mode = RotaryPosEmbeddingMode.BLOCKWISE
cos = torch.cat((cos, cos), dim=-1)
sin = torch.cat((sin, sin), dim=-1)
else:
rope_mode = RotaryPosEmbeddingMode.PAIRWISE
sin = torch.repeat_interleave(sin,
2,
dim=-1,
output_size=cos_sin.shape[-1])
cos = torch.repeat_interleave(cos,
2,
dim=-1,
output_size=cos_sin.shape[-1])
query_shape = query.shape
query = query.view(num_tokens, -1, self.head_size)
query_rot = query[..., :self.rotary_dim]
query_pass = query[..., self.rotary_dim:]
query_rot = apply_rotary_pos_emb(query_rot, cos, sin, None, 0,
rope_mode)
query = torch.cat((query_rot, query_pass), dim=-1).reshape(query_shape)
key_shape = key.shape
key = key.view(num_tokens, -1, self.head_size)
key_rot = key[..., :self.rotary_dim]
key_pass = key[..., self.rotary_dim:]
key_rot = apply_rotary_pos_emb(key_rot, cos, sin, None, 0, rope_mode)
key = torch.cat((key_rot, key_pass), dim=-1).reshape(key_shape)
return query, key
def extra_repr(self) -> str:
s = f"head_size={self.head_size}, rotary_dim={self.rotary_dim}"
s += f", max_position_embeddings={self.max_position_embeddings}"
s += f", base={self.base}, is_neox_style={self.is_neox_style}"
return s
class LinearScalingRotaryEmbedding(RotaryEmbedding):
"""RotaryEmbedding extended with linear scaling.
It supports multiple scaling factors. Since multiple LoRA adapters may have
different scaling factors, we need multiple cos/sin caches. In this way,
instead of running rotary embedding kernel per lora, we can run multiple
lora in a batched way.
In addition to that, we also keep the cos/sin cache for the scaling factor
of 1 (default) at all times.
Exemplary for two scaling factors x=1, y and z with embeddings
[[x11, x12, ... x1m], ..., [xn1, xn2, ..., xnm]] and
[[y11, y12, ... y1o], ..., [yn1, yn2, ..., yno]], and
[[z11, z12, ... z1p], ..., [zn1, zn2, ..., znp]],
we construct the cos/sin cache as follows:
[[x11, x12, ... x1m, y11, y12, ... y1o, z11, z12, ... z1p],
...
[xn1, xn2, ... xnm, yn1, yn2, ... yno, zn1, zn2, ... znp]]
We then use offsets to index into the cos/sin cache for
the respective scaling factors.
The offset to cache can be accessed via `scaling_factor_to_offset` API.
Credits to the Reddit user /u/kaiokendev
"""
def __init__(
self,
head_size: int,
rotary_dim: int,
max_position_embeddings: int,
base: int,
is_neox_style: bool,
scaling_factors: Union[List[float], float],
dtype: torch.dtype,
) -> None:
if isinstance(scaling_factors, float):
scaling_factors = [scaling_factors]
self.scaling_factors: List[float] = scaling_factors # noqa
super().__init__(head_size, rotary_dim, max_position_embeddings, base,
is_neox_style, dtype)
# Lazy initialized.
self._scaling_factor_to_offset: Dict[float, int]
def _compute_cos_sin_cache(self) -> torch.Tensor:
inv_freq = self._compute_inv_freq(self.base)
cache_list: List[torch.Tensor] = []
# offsets to the next cache in a tensor.
# Each offset corresponds to the same index in scaling_factors.
offsets: List[int] = []
for scaling_factor in self.scaling_factors:
# NOTE(woosuk): self.max_position_embeddings is the original
# maximum length before applying the rope scaling.
# Thus, the maximum length after applying the rope scaling is
# self.max_position_embeddings * self.scaling_factor.
max_len = self.max_position_embeddings * scaling_factor
t = torch.arange(max_len, dtype=torch.float)
t = t / scaling_factor
freqs = torch.einsum("i,j -> ij", t, inv_freq)
cos = freqs.cos()
sin = freqs.sin()
cache = torch.cat((cos, sin), dim=-1)
if not cache_list:
offset = 0
else:
last_offset = offsets[-1]
next_max_len = cache_list[-1].shape[0]
offset = last_offset + next_max_len
offsets.append(offset)
cache_list.append(cache)
self._scaling_factor_to_offset = {
float(scaling_factor): offsets[i]
for i, scaling_factor in enumerate(self.scaling_factors)
}
assert len(self.scaling_factors) == len(offsets)
return torch.cat(cache_list, dim=0)
@property
def scaling_factor_to_offset(self) -> Dict[float, int]:
return self._scaling_factor_to_offset
class DynamicNTKScalingRotaryEmbedding(RotaryEmbedding):
"""RotaryEmbedding extended with Dynamic NTK scaling.
Credits to the Reddit users /u/bloc97 and /u/emozilla
"""
def __init__(
self,
head_size: int,
rotary_dim: int,
max_position_embeddings: int,
base: int,
is_neox_style: bool,
scaling_factor: float,
dtype: torch.dtype,
) -> None:
self.scaling_factor = scaling_factor
super().__init__(head_size, rotary_dim, max_position_embeddings, base,
is_neox_style, dtype)
def _compute_cos_sin_cache(self) -> torch.Tensor:
# NOTE(woosuk): self.max_position_embeddings is the original
# maximum length before applying the rope scaling.
# Thus, the maximum length after applying the rope scaling is
# self.max_position_embeddings * self.scaling_factor.
max_len = self.max_position_embeddings * self.scaling_factor
base = self.base * (
(self.scaling_factor * max_len / self.max_position_embeddings) -
(self.scaling_factor - 1))**(self.rotary_dim /
(self.rotary_dim - 2))
inv_freq = self._compute_inv_freq(base)
t = torch.arange(max_len, dtype=torch.float)
freqs = torch.einsum("i,j -> ij", t, inv_freq)
cos = freqs.cos()
sin = freqs.sin()
cache = torch.cat((cos, sin), dim=-1)
return cache
# Inverse dim formula to find dim based on number of rotations
def _yarn_find_correction_dim(num_rotations: int,
dim: int,
base: float = 10000,
max_position_embeddings: int = 2048) -> float:
return (dim * math.log(max_position_embeddings /
(num_rotations * 2 * math.pi))) / (2 *
math.log(base))
# Find dim range bounds based on rotations
def _yarn_find_correction_range(
low_rot: int,
high_rot: int,
dim: int,
base: float = 10000,
max_position_embeddings: int = 2048) -> Tuple[int, int]:
low = math.floor(
_yarn_find_correction_dim(low_rot, dim, base, max_position_embeddings))
high = math.ceil(
_yarn_find_correction_dim(high_rot, dim, base,
max_position_embeddings))
return max(low, 0), min(high, dim - 1) # Clamp values just in case
def _yarn_linear_ramp_mask(low: float, high: float, dim: int,
dtype: torch.dtype) -> torch.Tensor:
if low == high:
high += 0.001 # Prevent singularity
linear_func = (torch.arange(dim, dtype=dtype) - low) / (high - low)
ramp_func = torch.clamp(linear_func, 0, 1)
return ramp_func
def _yarn_get_mscale(scale: float = 1) -> float:
if scale <= 1:
return 1.0
return 0.1 * math.log(scale) + 1.0
class YaRNScalingRotaryEmbedding(RotaryEmbedding):
"""RotaryEmbedding extended with YaRN method.
Credits to Peng et al. github.com/jquesnelle/yarn
"""
def __init__(
self,
head_size: int,
rotary_dim: int,
max_position_embeddings: int,
base: int,
is_neox_style: bool,
scaling_factor: float,
dtype: torch.dtype,
*,
extrapolation_factor: float = 1,
attn_factor: float = 1,
beta_fast: int = 32,
beta_slow: int = 1,
) -> None:
self.scaling_factor = scaling_factor
self.extrapolation_factor = extrapolation_factor
self.attn_factor = attn_factor
self.beta_fast = beta_fast
self.beta_slow = beta_slow
# Get n-d magnitude scaling corrected for interpolation
self.mscale = float(
_yarn_get_mscale(self.scaling_factor) * attn_factor)
super().__init__(head_size, rotary_dim, max_position_embeddings, base,
is_neox_style, dtype)
def _compute_inv_freq(self, scaling_factor: float) -> torch.Tensor:
pos_freqs = self.base**(
torch.arange(0, self.rotary_dim, 2, dtype=torch.float) /
self.rotary_dim)
inv_freq_extrapolation = 1.0 / pos_freqs
inv_freq_interpolation = 1.0 / (scaling_factor * pos_freqs)
low, high = _yarn_find_correction_range(self.beta_fast, self.beta_slow,
self.rotary_dim, self.base,
self.max_position_embeddings)
# Get n-d rotational scaling corrected for extrapolation
inv_freq_mask = (1 - _yarn_linear_ramp_mask(
low, high, self.rotary_dim // 2,
dtype=torch.float)) * self.extrapolation_factor
inv_freq = inv_freq_interpolation * (
1 - inv_freq_mask) + inv_freq_extrapolation * inv_freq_mask
return inv_freq
def _compute_cos_sin_cache(self) -> torch.Tensor:
inv_freq = self._compute_inv_freq(self.scaling_factor)
t = torch.arange(self.max_position_embeddings * self.scaling_factor,
dtype=torch.float32)
freqs = torch.einsum("i,j -> ij", t, inv_freq)
cos = (freqs.cos() * self.mscale)
sin = (freqs.sin() * self.mscale)
cache = torch.cat((cos, sin), dim=-1)
return cache
class Phi3LongRoPEScaledRotaryEmbedding(nn.Module):
"""Phi3 family of models scaled rotary embedding.
Based on the original RotaryEmbedding implementation.
"""
def __init__(
self,
head_size: int,
rotary_dim: int,
max_position_embeddings: int,
original_max_position_embeddings: int,
base: int,
is_neox_style: bool,
dtype: torch.dtype,
short_factor: List[float],
long_factor: List[float],
short_mscale: Optional[float] = None,
long_mscale: Optional[float] = None,
):
super().__init__()
if rotary_dim != head_size:
raise ValueError(
f"`Phi3LongRoPEScaledRotaryEmbedding` does not support \
rotary_dim != head_size ({rotary_dim}!={head_size}).")
if is_neox_style is False:
raise ValueError(
"`Phi3LongRoPEScaledRotaryEmbedding` only supports neox_style."
)
self.head_size = head_size
self.max_position_embeddings = max_position_embeddings
self.original_max_position_embeddings = original_max_position_embeddings
self.base = base
self.short_factor = short_factor
self.long_factor = long_factor
scale = self.max_position_embeddings / \
self.original_max_position_embeddings
if scale <= 1.0:
scaling_factor = 1.0
else:
scaling_factor = math.sqrt(
1 + math.log(scale) /
math.log(self.original_max_position_embeddings))
if short_mscale is None:
short_mscale = scaling_factor
if long_mscale is None:
long_mscale = scaling_factor
self.short_mscale = short_mscale
self.long_mscale = long_mscale
short_cache = self._compute_cos_sin_cache(
original_max_position_embeddings, short_factor, short_mscale)
short_cache = short_cache.to(dtype)
long_cache = self._compute_cos_sin_cache(max_position_embeddings,
long_factor, long_mscale)
long_cache = long_cache.to(dtype)
long_short_cache = torch.cat([short_cache, long_cache], dim=0)
self.register_buffer("long_short_cos_sin_cache",
long_short_cache,
persistent=False)
def _compute_inv_freq(self, rescale_factors: List[float]) -> torch.Tensor:
rescale_factors = torch.tensor(rescale_factors, dtype=torch.float32)
inv_freq = 1.0 / (rescale_factors * (self.base**(torch.arange(
0, self.head_size, 2, dtype=torch.float) / self.head_size)))
return inv_freq
def _compute_cos_sin_cache(
self,
max_position_embeddings: int,
rescale_factors: List[float],
mscale: float,
) -> torch.Tensor:
inv_freq = self._compute_inv_freq(rescale_factors)
t = torch.arange(max_position_embeddings, dtype=torch.float)
freqs = torch.einsum("i,j -> ij", t, inv_freq)
cos = freqs.cos() * mscale
sin = freqs.sin() * mscale
cache = torch.cat((cos, sin), dim=-1)
return cache
def forward(
self,
positions: torch.Tensor,
query: torch.Tensor,
key: torch.Tensor,
offsets: Optional[torch.Tensor] = None,
) -> Tuple[torch.Tensor, torch.Tensor]:
query = query.view(*query.shape[:-1], -1, self.head_size)
key = key.view(*key.shape[:-1], -1, self.head_size)
k = self.original_max_position_embeddings
long_prompt_offset = (torch.any(positions > k).float() *
torch.full_like(positions, k)).long()
idx = (torch.add(positions, long_prompt_offset)
if long_prompt_offset is not None else positions)
idx = torch.add(idx, offsets) if offsets is not None else idx
cos_sin = torch.index_select(self.long_short_cos_sin_cache, 0, idx)
cos, sin = cos_sin.chunk(2, dim=-1)
cos = cos.repeat(1, 2).unsqueeze(-2)
sin = sin.repeat(1, 2).unsqueeze(-2)
query = query * cos + _rotate_neox(query) * sin
key = key * cos + _rotate_neox(key) * sin
return query.flatten(-2), key.flatten(-2)
def yarn_get_mscale(scale: float = 1, mscale: float = 1) -> float:
if scale <= 1:
return 1.0
return 0.1 * mscale * math.log(scale) + 1.0
class DeepseekScalingRotaryEmbedding(RotaryEmbedding):
"""RotaryEmbedding extended with YaRN method.
Credits to Peng et al. github.com/jquesnelle/yarn
"""
def __init__(
self,
head_size: int,
rotary_dim: int,
max_position_embeddings: int,
base: int,
is_neox_style: bool,
scaling_factor: float,
dtype: torch.dtype,
*,
extrapolation_factor: float = 1,
attn_factor: float = 1,
beta_fast: int = 32,
beta_slow: int = 1,
mscale: float = 1,
mscale_all_dim: float = 0,
) -> None:
self.scaling_factor = scaling_factor
self.extrapolation_factor = extrapolation_factor
self.attn_factor = attn_factor
self.beta_fast = beta_fast
self.beta_slow = beta_slow
# Get n-d magnitude scaling corrected for interpolation.
self.mscale = float(
yarn_get_mscale(self.scaling_factor, float(mscale)) /
yarn_get_mscale(self.scaling_factor, float(mscale_all_dim)) *
attn_factor)
super().__init__(head_size, rotary_dim, max_position_embeddings, base,
is_neox_style, dtype)
def _compute_inv_freq(self, scaling_factor: float) -> torch.Tensor:
pos_freqs = self.base**(torch.arange(
0, self.rotary_dim, 2, dtype=torch.float, device="cuda") /
self.rotary_dim)
inv_freq_extrapolation = 1.0 / pos_freqs
inv_freq_interpolation = 1.0 / (scaling_factor * pos_freqs)
low, high = _yarn_find_correction_range(self.beta_fast, self.beta_slow,
self.rotary_dim, self.base,
self.max_position_embeddings)
# Get n-d rotational scaling corrected for extrapolation
inv_freq_mask = (1 - _yarn_linear_ramp_mask(
low, high, self.rotary_dim // 2,
dtype=torch.float)) * self.extrapolation_factor
inv_freq = inv_freq_interpolation * (
1 - inv_freq_mask) + inv_freq_extrapolation * inv_freq_mask
return inv_freq
def _compute_cos_sin_cache(self) -> torch.Tensor:
inv_freq = self._compute_inv_freq(self.scaling_factor)
t = torch.arange(self.max_position_embeddings * self.scaling_factor,
device="cuda",
dtype=torch.float32)
freqs = torch.einsum("i,j -> ij", t, inv_freq)
cos = (freqs.cos() * self.mscale)
sin = (freqs.sin() * self.mscale)
cache = torch.cat((cos, sin), dim=-1)
return cache
def forward(
self,
positions: torch.Tensor,
query: torch.Tensor,
key: torch.Tensor,
offsets: Optional[torch.Tensor] = None,
) -> Tuple[torch.Tensor, torch.Tensor]:
"""PyTorch-native implementation equivalent to forward()."""
query_rot = query[..., :self.rotary_dim]
key_rot = key[..., :self.rotary_dim]
if self.rotary_dim < self.head_size:
query_pass = query[..., self.rotary_dim:]
key_pass = key[..., self.rotary_dim:]
self.cos_sin_cache: torch.Tensor = self.cos_sin_cache.to(
positions.device)
cos_sin = self.cos_sin_cache[torch.add(positions, offsets)
if offsets is not None else positions]
cos, sin = cos_sin.chunk(2, dim=-1)
if self.is_neox_style:
# NOTE(woosuk): Here we assume that the positions tensor has the
# shape [batch_size, seq_len].
cos = cos.repeat(1, 1, 2).unsqueeze(-2)
sin = sin.repeat(1, 1, 2).unsqueeze(-2)
else:
cos = cos.repeat_interleave(2, dim=-1).unsqueeze(-2)
sin = sin.repeat_interleave(2, dim=-1).unsqueeze(-2)
rotate_fn = _rotate_neox if self.is_neox_style else _rotate_gptj
query_rot = query_rot * cos + rotate_fn(query_rot) * sin
key_rot = key_rot * cos + rotate_fn(key_rot) * sin
if self.rotary_dim < self.head_size:
query = torch.cat((query_rot, query_pass), dim=-1)
key = torch.cat((key_rot, key_pass), dim=-1)
else:
query = query_rot
key = key_rot
return query, key
class Llama3RotaryEmbedding(RotaryEmbedding):
def __init__(
self,
head_size: int,
rotary_dim: int,
max_position_embeddings: int,
base: int,
is_neox_style: bool,
dtype: torch.dtype,
scaling_factor: float,
low_freq_factor: float,
high_freq_factor: float,
orig_max_position: int,
) -> None:
self.scaling_factor = scaling_factor
self.low_freq_factor = low_freq_factor
self.high_freq_factor = high_freq_factor
self.orig_max_position = orig_max_position
super().__init__(head_size, rotary_dim, max_position_embeddings, base,
is_neox_style, dtype)
def _compute_inv_freq(self, base: Union[int, float]) -> torch.Tensor:
inv_freqs = super()._compute_inv_freq(base)
low_freq_wavelen = self.orig_max_position / self.low_freq_factor
high_freq_wavelen = self.orig_max_position / self.high_freq_factor
wave_len = 2 * math.pi / inv_freqs
if self.low_freq_factor != self.high_freq_factor:
smooth = (self.orig_max_position / wave_len - self.low_freq_factor
) / (self.high_freq_factor - self.low_freq_factor)
else:
smooth = 0
new_freqs = torch.where(
wave_len < high_freq_wavelen,
inv_freqs,
torch.where(
wave_len > low_freq_wavelen,
inv_freqs / self.scaling_factor,
(1 - smooth) * inv_freqs / self.scaling_factor +
smooth * inv_freqs,
),
)
return new_freqs
class MRotaryEmbedding(RotaryEmbedding):
"""Rotary Embedding with Multimodal Sections."""
def __init__(
self,
head_size: int,
rotary_dim: int,
max_position_embeddings: int,
base: int,
is_neox_style: bool,
dtype: torch.dtype,
mrope_section: Optional[List[int]] = None,
) -> None:
super().__init__(head_size, rotary_dim, max_position_embeddings, base,
is_neox_style, dtype)
self.mrope_section = mrope_section
if self.mrope_section:
assert sum(self.mrope_section) == rotary_dim // 2
def forward(
self,
positions: torch.Tensor,
query: torch.Tensor,
key: torch.Tensor,
) -> Tuple[torch.Tensor, torch.Tensor]:
"""PyTorch-native implementation equivalent to forward().
Args:
positions:
[num_tokens,] (text only) or
[3, num_tokens] (T/H/W positions with multimodal inputs)
query: [num_tokens, num_heads * head_size]
key: [num_tokens, num_kv_heads * head_size]
"""
assert positions.ndim == 1 or positions.ndim == 2
num_tokens = positions.shape[-1]
cos_sin = self.cos_sin_cache[positions]
cos, sin = cos_sin.chunk(2, dim=-1)
if positions.ndim == 2:
assert self.mrope_section
cos = torch.cat([
m[i]
for i, m in enumerate(cos.split(self.mrope_section, dim=-1))
],
dim=-1)
sin = torch.cat([
m[i]
for i, m in enumerate(sin.split(self.mrope_section, dim=-1))
],
dim=-1)
query_shape = query.shape
query = query.view(num_tokens, -1, self.head_size)
query_rot = query[..., :self.rotary_dim]
query_pass = query[..., self.rotary_dim:]
query_rot = _apply_rotary_emb(query_rot, cos, sin, self.is_neox_style)
query = torch.cat((query_rot, query_pass), dim=-1).reshape(query_shape)
key_shape = key.shape
key = key.view(num_tokens, -1, self.head_size)
key_rot = key[..., :self.rotary_dim]
key_pass = key[..., self.rotary_dim:]
key_rot = _apply_rotary_emb(key_rot, cos, sin, self.is_neox_style)
key = torch.cat((key_rot, key_pass), dim=-1).reshape(key_shape)
return query, key
@staticmethod
def get_input_positions(
input_tokens: List[int],
image_grid_thw: Union[List[List[int]], torch.Tensor],
video_grid_thw: Union[List[List[int]], torch.Tensor],
image_token_id: int,
video_token_id: int,
vision_start_token_id: int,
vision_end_token_id: int,
spatial_merge_size: int,
context_len: int = 0,
seq_len: Optional[int] = None,
) -> Tuple[List[List[int]], int]:
"""Get mrope input positions and delta value."""
llm_positions, mrope_position_delta = \
MRotaryEmbedding.get_input_positions_tensor(
input_tokens,
image_grid_thw,
video_grid_thw,
image_token_id,
video_token_id,
vision_start_token_id,
vision_end_token_id,
spatial_merge_size,
context_len,
seq_len,
)
return llm_positions.tolist(), mrope_position_delta
@staticmethod
def get_input_positions_tensor(
input_tokens: List[int],
image_grid_thw: Union[List[List[int]], torch.Tensor],
video_grid_thw: Union[List[List[int]], torch.Tensor],
image_token_id: int,
video_token_id: int,
vision_start_token_id: int,
vision_end_token_id: int,
spatial_merge_size: int,
context_len: int = 0,
seq_len: Optional[int] = None,
) -> Tuple[torch.Tensor, int]:
"""Get mrope input positions and delta value."""
if isinstance(image_grid_thw, torch.Tensor):
image_grid_thw = image_grid_thw.tolist()
if isinstance(video_grid_thw, torch.Tensor):
video_grid_thw = video_grid_thw.tolist()
input_tokens_tensor = torch.tensor(input_tokens)
vision_start_indices = torch.argwhere(
input_tokens_tensor == vision_start_token_id).squeeze(1)
vision_tokens = input_tokens_tensor[vision_start_indices + 1]
image_nums = (vision_tokens == image_token_id).sum()
video_nums = (vision_tokens == video_token_id).sum()
llm_pos_ids_list: list = []
st = 0
remain_images, remain_videos = image_nums, video_nums
image_index, video_index = 0, 0
for _ in range(image_nums + video_nums):
if image_token_id in input_tokens and remain_images > 0:
ed_image = input_tokens.index(image_token_id, st)
else:
ed_image = len(input_tokens) + 1
if video_token_id in input_tokens and remain_videos > 0:
ed_video = input_tokens.index(video_token_id, st)
else:
ed_video = len(input_tokens) + 1
if ed_image < ed_video:
t, h, w = (
image_grid_thw[image_index][0],
image_grid_thw[image_index][1],
image_grid_thw[image_index][2],
)
image_index += 1
remain_images -= 1
ed = ed_image
else:
t, h, w = (
video_grid_thw[video_index][0],
video_grid_thw[video_index][1],
video_grid_thw[video_index][2],
)
video_index += 1
remain_videos -= 1
ed = ed_video
llm_grid_t, llm_grid_h, llm_grid_w = \
t, h // spatial_merge_size, w // spatial_merge_size
text_len = ed - st
st_idx = llm_pos_ids_list[-1].max() + 1 if len(
llm_pos_ids_list) > 0 else 0
llm_pos_ids_list.append(
torch.arange(text_len).view(1, -1).expand(3, -1) + st_idx)
t_index = torch.arange(llm_grid_t).view(-1, 1).expand(
-1, llm_grid_h * llm_grid_w).flatten()
h_index = torch.arange(llm_grid_h).view(1, -1, 1).expand(
llm_grid_t, -1, llm_grid_w).flatten()
w_index = torch.arange(llm_grid_w).view(1, 1, -1).expand(
llm_grid_t, llm_grid_h, -1).flatten()
llm_pos_ids_list.append(
torch.stack([t_index, h_index, w_index]) + text_len + st_idx)
st = ed + llm_grid_t * llm_grid_h * llm_grid_w
if st < len(input_tokens):
st_idx = llm_pos_ids_list[-1].max() + 1 if len(
llm_pos_ids_list) > 0 else 0
text_len = len(input_tokens) - st
llm_pos_ids_list.append(
torch.arange(text_len).view(1, -1).expand(3, -1) + st_idx)
llm_positions = torch.cat(llm_pos_ids_list, dim=1).reshape(3, -1)
mrope_position_delta = (llm_positions.max() + 1 -
len(input_tokens)).item()
llm_positions = llm_positions[:, context_len:seq_len]
return llm_positions, mrope_position_delta
@staticmethod
def get_next_input_positions(
mrope_position_delta: int,
context_len: int,
seq_len: int,
) -> List[List[int]]:
return [
list(
range(context_len + mrope_position_delta,
seq_len + mrope_position_delta)) for _ in range(3)
]
@staticmethod
def get_next_input_positions_tensor(
mrope_position_delta: int,
context_len: int,
seq_len: int,
) -> torch.Tensor:
return torch.arange(
mrope_position_delta + context_len,
mrope_position_delta + seq_len,
).expand(3, -1)
_ROPE_DICT: Dict[Tuple, RotaryEmbedding] = {}
def get_rope(
head_size: int,
rotary_dim: int,
max_position: int,
base: int,
is_neox_style: bool = True,
rope_scaling: Optional[Dict[str, Any]] = None,
dtype: Optional[torch.dtype] = None,
partial_rotary_factor: float = 1.0,
) -> RotaryEmbedding:
if dtype is None:
dtype = torch.get_default_dtype()
if rope_scaling is not None:
# Transforms every value that is a list into a tuple for caching calls
rope_scaling_tuple = {
k: tuple(v) if isinstance(v, list) else v
for k, v in rope_scaling.items()
}
rope_scaling_args = tuple(rope_scaling_tuple.items())
else:
rope_scaling_args = None
if partial_rotary_factor < 1.0:
rotary_dim = int(rotary_dim * partial_rotary_factor)
key = (head_size, rotary_dim, max_position, base, is_neox_style,
rope_scaling_args, dtype)
if key in _ROPE_DICT:
return _ROPE_DICT[key]
if rope_scaling is None:
rotary_emb = RotaryEmbedding(head_size, rotary_dim, max_position, base,
is_neox_style, dtype)
else:
scaling_type = rope_scaling["rope_type"]
if scaling_type == "llama3":
scaling_factor = rope_scaling["factor"]
low_freq_factor = rope_scaling["low_freq_factor"]
high_freq_factor = rope_scaling["high_freq_factor"]
original_max_position = rope_scaling[
"original_max_position_embeddings"]
rotary_emb = Llama3RotaryEmbedding(head_size, rotary_dim,
max_position, base,
is_neox_style, dtype,
scaling_factor, low_freq_factor,
high_freq_factor,
original_max_position)
elif scaling_type == "default":
if "mrope_section" in rope_scaling:
rotary_emb = MRotaryEmbedding(
head_size,
rotary_dim,
max_position,
base,
is_neox_style,
dtype,
mrope_section=rope_scaling["mrope_section"],
)
else:
rotary_emb = RotaryEmbedding(
head_size,
rotary_dim,
max_position,
base,
is_neox_style,
dtype,
)
elif scaling_type == "linear":
scaling_factor = rope_scaling["factor"]
rotary_emb = LinearScalingRotaryEmbedding(head_size, rotary_dim,
max_position, base,
is_neox_style,
scaling_factor, dtype)
elif scaling_type == "dynamic":
scaling_factor = rope_scaling["factor"]
rotary_emb = DynamicNTKScalingRotaryEmbedding(
head_size, rotary_dim, max_position, base, is_neox_style,
scaling_factor, dtype)
elif scaling_type == "yarn":
scaling_factor = rope_scaling["factor"]
original_max_position = rope_scaling[
"original_max_position_embeddings"]
extra_kwargs = {
k: v
for k, v in rope_scaling.items()
if k in ("extrapolation_factor", "attn_factor", "beta_fast",
"beta_slow")
}
rotary_emb = YaRNScalingRotaryEmbedding(head_size, rotary_dim,
original_max_position,
base, is_neox_style,
scaling_factor, dtype,
**extra_kwargs)
elif scaling_type == "deepseek_yarn":
scaling_factor = rope_scaling["factor"]
original_max_position = rope_scaling[
"original_max_position_embeddings"]
# assert max_position == original_max_position * scaling_factor
extra_kwargs = {
k: v
for k, v in rope_scaling.items()
if k in ("extrapolation_factor", "attn_factor", "beta_fast",
"beta_slow", "mscale", "mscale_all_dim")
}
rotary_emb = DeepseekScalingRotaryEmbedding(
head_size, rotary_dim, original_max_position, base,
is_neox_style, scaling_factor, dtype, **extra_kwargs)
elif scaling_type == "longrope":
short_factor = rope_scaling["short_factor"]
long_factor = rope_scaling["long_factor"]
original_max_position = rope_scaling[
"original_max_position_embeddings"]
extra_kwargs = {
k: v
for k, v in rope_scaling.items()
if k in ("short_mscale", "long_mscale")
}
rotary_emb = Phi3LongRoPEScaledRotaryEmbedding(
head_size, rotary_dim, max_position, original_max_position,
base, is_neox_style, dtype, short_factor, long_factor,
**extra_kwargs)
else:
raise ValueError(f"Unknown RoPE scaling type {scaling_type}")
_ROPE_DICT[key] = rotary_emb
return rotary_emb