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chore: import upstream snapshot with attribution
2026-07-13 12:32:31 +08:00

1469 lines
53 KiB
Python
Executable File

# Copyright (c) 2026 LightSeek Foundation
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
"""Rotary Positional Embeddings."""
import itertools
import logging
import math
from typing import Any
import torch
import torch.nn as nn
from tokenspeed_kernel.ops.embedding import FusedSetKVBufferArg, apply_rope
from tokenspeed_kernel.platform import current_platform
from tokenspeed_kernel.torch_compile import get_compiler_backend
_is_nvidia = current_platform().is_nvidia
logger = logging.getLogger(__name__)
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)
# Copied from transformers
def rotate_half(x):
"""Rotates half the hidden dims of the input."""
x1 = x[..., : x.shape[-1] // 2]
x2 = x[..., x.shape[-1] // 2 :]
return torch.cat((-x2, x1), dim=-1)
@torch.compile(dynamic=True, backend=get_compiler_backend())
def apply_rotary_pos_emb_native(
q: torch.Tensor,
k: torch.Tensor,
cos: torch.Tensor,
sin: torch.Tensor,
unsqueeze_dim=1,
) -> tuple[torch.Tensor, torch.Tensor]:
orig_q_dtype = q.dtype
orig_k_dtype = k.dtype
q, k = q.float(), k.float()
# embedding is performed in float
cos = cos.unsqueeze(unsqueeze_dim).float()
sin = sin.unsqueeze(unsqueeze_dim).float()
q_embed = (q * cos) + (rotate_half(q) * sin)
k_embed = (k * cos) + (rotate_half(k) * sin)
q_embed = q_embed.to(orig_q_dtype)
k_embed = k_embed.to(orig_k_dtype)
return q_embed, k_embed
def apply_interleaved_rope(x: torch.Tensor, mrope_section: list) -> torch.Tensor:
x_t = x[0].clone()
x_t[..., 1 : mrope_section[1] * 3 : 3] = x[1, ..., 1 : mrope_section[1] * 3 : 3]
x_t[..., 2 : mrope_section[2] * 3 : 3] = x[2, ..., 2 : mrope_section[2] * 3 : 3]
return x_t
class RotaryEmbedding(torch.nn.Module):
"""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()
self.cos_sin_cache: torch.Tensor
self.register_buffer("cos_sin_cache", cache, persistent=False)
def _compute_inv_freq(self, base: int | float) -> torch.Tensor:
"""Compute the inverse frequency."""
# 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(
self,
positions: torch.Tensor,
query: torch.Tensor,
key: torch.Tensor,
offsets: torch.Tensor | None = None,
fused_set_kv_buffer_arg: FusedSetKVBufferArg | None = None,
output_q_rope: torch.Tensor | None = None,
output_k_rope: torch.Tensor | None = None,
enable_pdl: bool = False,
) -> tuple[torch.Tensor, torch.Tensor]:
if offsets is not None:
raise ValueError("embedding.rope does not support offsets")
return apply_rope(
positions=positions,
q=query,
k=key,
head_size=self.head_size,
cos_sin_cache=self.cos_sin_cache,
is_neox=self.is_neox_style,
fused_set_kv_buffer_arg=fused_set_kv_buffer_arg,
q_rope_out=output_q_rope,
k_rope_out=output_k_rope,
enable_pdl=enable_pdl,
)
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: list[float] | float,
dtype: torch.dtype,
) -> None:
if isinstance(scaling_factors, float):
scaling_factors = [scaling_factors]
self.scaling_factors: list[float] = scaling_factors
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:
# 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)
}
if len(self.scaling_factors) != len(offsets):
raise RuntimeError("scaling factor offsets were not initialized correctly.")
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:
# 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, device: torch.device = None
) -> torch.Tensor:
if low == high:
high += 0.001 # Prevent singularity
linear_func = (torch.arange(dim, dtype=dtype, device=device) - 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."""
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: float | None = None,
long_mscale: float | None = None,
):
super().__init__()
if is_neox_style is False:
raise ValueError(
"`Phi3LongRoPEScaledRotaryEmbedding` only supports neox_style."
)
self.rotary_dim = rotary_dim
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)
self.register_buffer("short_cos_sin_cache", short_cache, persistent=False)
long_cache = self._compute_cos_sin_cache(
max_position_embeddings, long_factor, long_mscale
)
long_cache = long_cache.to(dtype)
self.register_buffer("long_cos_sin_cache", long_cache, persistent=False)
long_short_cache = torch.cat(
[self.short_cos_sin_cache, self.long_cos_sin_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.rotary_dim, 2, dtype=torch.float)
/ self.rotary_dim
)
)
)
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: torch.Tensor | None = 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
)
self.long_short_cos_sin_cache: torch.Tensor = self.long_short_cos_sin_cache.to(
idx.device
)
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_rot = query[..., : self.rotary_dim]
query_pass = query[..., self.rotary_dim :]
query_rot = query_rot * cos + _rotate_neox(query_rot) * sin
query = torch.cat((query_rot, query_pass), dim=-1)
key_rot = key[..., : self.rotary_dim]
key_pass = key[..., self.rotary_dim :]
key_rot = key_rot * cos + _rotate_neox(key_rot) * sin
key = torch.cat((key_rot, key_pass), dim=-1)
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,
device: str | None = "cuda",
) -> 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
)
self.device = device
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=self.device)
/ 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, device=self.device
)
) * 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=self.device,
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,
fused_set_kv_buffer_arg=None,
output_q_rope=None,
offsets: torch.Tensor | None = None,
) -> tuple[torch.Tensor, torch.Tensor]:
if _is_nvidia:
return super().forward(
positions=positions,
query=query,
key=key,
fused_set_kv_buffer_arg=fused_set_kv_buffer_arg,
output_q_rope=output_q_rope,
offsets=offsets,
)
dtype = query.dtype
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:
# 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.to(dtype), key.to(dtype)
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: 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 DynamicNTKAlphaRotaryEmbedding(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_alpha: float,
dtype: torch.dtype,
) -> None:
self.scaling_alpha = scaling_alpha
super().__init__(
head_size, rotary_dim, max_position_embeddings, base, is_neox_style, dtype
)
def _compute_cos_sin_cache(self) -> torch.Tensor:
max_len = self.max_position_embeddings
base = self.base * self.scaling_alpha ** (
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
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: list[int] | None = None,
mrope_interleaved: bool = False,
) -> None:
super().__init__(
head_size, rotary_dim, max_position_embeddings, base, is_neox_style, dtype
)
self.mrope_section = mrope_section
self.mrope_interleaved = mrope_interleaved
if self.mrope_section:
expected_sum = rotary_dim // 2
actual_sum = sum(self.mrope_section)
if actual_sum != expected_sum:
logger.warning(
f"MRoPE section sum mismatch: expected {expected_sum}, got {actual_sum}. "
f"Adjusting mrope_section to match rotary_dim // 2 = {expected_sum}"
)
# Auto-correct by scaling the mrope_section proportionally
if actual_sum > 0:
scale_factor = expected_sum / actual_sum
self.mrope_section = [
max(1, int(section * scale_factor))
for section in self.mrope_section
]
# Ensure the sum exactly matches by adjusting the last element
current_sum = sum(self.mrope_section)
if current_sum != expected_sum:
self.mrope_section[-1] += expected_sum - current_sum
else:
# If all sections are 0, create a default distribution
self.mrope_section = [
expected_sum // len(self.mrope_section)
] * len(self.mrope_section)
# Handle remainder
remainder = expected_sum % len(self.mrope_section)
for i in range(remainder):
self.mrope_section[i] += 1
logger.warning(
f"Corrected mrope_section: {self.mrope_section} (sum={sum(self.mrope_section)})"
)
@torch.compile(dynamic=True, backend=get_compiler_backend())
def forward(
self,
positions: torch.Tensor,
query: torch.Tensor,
key: torch.Tensor,
fused_set_kv_buffer_arg: FusedSetKVBufferArg | None = None,
) -> 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]
"""
if fused_set_kv_buffer_arg is not None:
raise ValueError("save kv cache is not supported for MRotaryEmbedding.")
if positions.ndim not in (1, 2):
raise ValueError(f"positions must be 1D or 2D, got ndim={positions.ndim}.")
num_tokens = positions.shape[-1]
cos_sin = self.cos_sin_cache[positions]
cos, sin = cos_sin.chunk(2, dim=-1)
if positions.ndim == 2:
if not self.mrope_section:
raise RuntimeError("mrope_section must be set for 2D M-RoPE.")
if self.mrope_interleaved:
cos = apply_interleaved_rope(cos, self.mrope_section)
sin = apply_interleaved_rope(sin, self.mrope_section)
else:
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_rope_index(
spatial_merge_size: int,
image_token_id: int,
video_token_id: int,
vision_start_token_id: int,
model_type: str,
tokens_per_second: int | None = None,
input_ids: torch.LongTensor | None = None,
image_grid_thw: torch.LongTensor | None = None,
video_grid_thw: torch.LongTensor | None = None,
second_per_grid_ts: torch.Tensor | None = None,
**kwargs,
) -> tuple[torch.Tensor, torch.Tensor]:
mrope_position_deltas = []
if input_ids is not None and (
image_grid_thw is not None or video_grid_thw is not None
):
total_input_ids = input_ids
position_ids = torch.ones(
3,
input_ids.shape[0],
input_ids.shape[1],
dtype=input_ids.dtype,
device=input_ids.device,
)
image_index, video_index = 0, 0
for i, input_ids in enumerate(total_input_ids):
image_nums, video_nums = 0, 0
vision_start_indices = torch.argwhere(
input_ids == vision_start_token_id
).squeeze(1)
vision_tokens = input_ids[vision_start_indices + 1]
image_nums = (vision_tokens == image_token_id).sum()
video_nums = (vision_tokens == video_token_id).sum()
input_tokens = input_ids.tolist()
llm_pos_ids_list: list = []
st = 0
remain_images, remain_videos = image_nums, video_nums
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],
)
second_per_grid_t = 0
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],
)
if second_per_grid_ts is not None:
second_per_grid_t = second_per_grid_ts[video_index]
else:
second_per_grid_t = 1.0
video_index += 1
remain_videos -= 1
ed = ed_video
llm_grid_t, llm_grid_h, llm_grid_w = (
t.item(),
h.item() // spatial_merge_size,
w.item() // 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
)
if model_type == "qwen2_5_vl":
range_tensor = torch.arange(llm_grid_t).view(-1, 1)
expanded_range = range_tensor.expand(
-1, llm_grid_h * llm_grid_w
)
time_tensor = (
expanded_range * second_per_grid_t * tokens_per_second
)
time_tensor_long = time_tensor.long()
t_index = time_tensor_long.flatten()
elif model_type in (
"qwen2_vl",
"qwen3_vl",
"qwen3_vl_moe",
"qwen3_5",
"qwen3_5_moe",
):
t_index = (
torch.arange(llm_grid_t)
.view(-1, 1)
.expand(-1, llm_grid_h * llm_grid_w)
.flatten()
)
else:
raise RuntimeError("Unimplemented")
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)
position_ids[..., i, :] = llm_positions.to(position_ids.device)
mrope_position_deltas.append(
llm_positions.max() + 1 - len(total_input_ids[i])
)
mrope_position_deltas = torch.tensor(
mrope_position_deltas, device=input_ids.device
).unsqueeze(1)
return position_ids, mrope_position_deltas
else:
s = input_ids.shape[1]
position_ids = torch.arange(s)
position_ids = (
position_ids.unsqueeze(0).expand(3, -1, -1).to(input_ids.device)
)
max_position_ids = position_ids.max(0, keepdim=False)[0].max(
-1, keepdim=True
)[0]
mrope_position_deltas = max_position_ids + 1 - s
return position_ids, mrope_position_deltas
@staticmethod
def get_rope_index_glm4v(
input_ids: torch.Tensor,
hf_config: Any,
image_grid_thw: list[list[int]] | torch.Tensor,
video_grid_thw: list[list[int]] | torch.Tensor,
attention_mask: torch.Tensor,
**kwargs,
) -> tuple[torch.Tensor, torch.Tensor]:
"""Get mrope input positions and delta value for GLM4V."""
image_token_id = hf_config.image_token_id
video_start_token_id = hf_config.video_start_token_id
video_end_token_id = hf_config.video_end_token_id
spatial_merge_size = hf_config.vision_config.spatial_merge_size
mrope_position_deltas = []
if input_ids is not None and (
image_grid_thw is not None or video_grid_thw is not None
):
total_input_ids = input_ids
if attention_mask is None:
attention_mask = torch.ones_like(total_input_ids)
position_ids = torch.ones(
3,
input_ids.shape[0],
input_ids.shape[1],
dtype=input_ids.dtype,
device=input_ids.device,
)
image_index, video_index = 0, 0
video_group_index = 0
attention_mask = attention_mask.to(total_input_ids.device)
for i, input_ids in enumerate(total_input_ids):
input_ids = input_ids[attention_mask[i] == 1]
input_tokens = input_ids.tolist()
input_token_type = []
video_check_flg = False
for token in input_tokens:
if token == video_start_token_id:
video_check_flg = True
elif token == video_end_token_id:
video_check_flg = False
if token == image_token_id and not video_check_flg:
input_token_type.append("image")
elif token == image_token_id and video_check_flg:
input_token_type.append("video")
else:
input_token_type.append("text")
input_type_group = []
for key, group in itertools.groupby(
enumerate(input_token_type), lambda x: x[1]
):
group = list(group)
start_index = group[0][0]
end_index = group[-1][0] + 1
input_type_group.append((key, start_index, end_index))
llm_pos_ids_list = []
video_frame_num = 1
for modality_type, start_idx, end_idx in input_type_group:
st_idx = (
llm_pos_ids_list[-1].max() + 1
if len(llm_pos_ids_list) > 0
else 0
)
if modality_type == "image":
t, h, w = (
image_grid_thw[image_index][0],
image_grid_thw[image_index][1],
image_grid_thw[image_index][2],
)
llm_grid_t, llm_grid_h, llm_grid_w = (
t.item(),
h.item() // spatial_merge_size,
w.item() // spatial_merge_size,
)
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]) + st_idx
)
image_index += 1
video_frame_num = 1
elif modality_type == "video":
t, h, w = (
video_frame_num,
video_grid_thw[video_index][1],
video_grid_thw[video_index][2],
)
llm_grid_t, llm_grid_h, llm_grid_w = (
t,
h.item() // spatial_merge_size,
w.item() // spatial_merge_size,
)
for t_idx in range(llm_grid_t):
t_index = (
torch.tensor(t_idx)
.view(-1, 1)
.expand(-1, llm_grid_h * llm_grid_w)
.flatten()
)
h_index = (
torch.arange(llm_grid_h)
.view(1, -1, 1)
.expand(1, -1, llm_grid_w)
.flatten()
)
w_index = (
torch.arange(llm_grid_w)
.view(1, 1, -1)
.expand(1, llm_grid_h, -1)
.flatten()
)
llm_pos_ids_list.append(
torch.stack([t_index, h_index, w_index]) + st_idx
)
video_group_index += 1
if video_group_index >= video_grid_thw[video_index][0]:
video_index += 1
video_group_index = 0
video_frame_num += 1
else:
text_len = end_idx - start_idx
llm_pos_ids_list.append(
torch.arange(text_len).view(1, -1).expand(3, -1) + st_idx
)
video_frame_num = 1
llm_positions = torch.cat(llm_pos_ids_list, dim=1).reshape(3, -1)
position_ids[..., i, attention_mask[i] == 1] = llm_positions.to(
position_ids.device
)
mrope_position_deltas.append(
llm_positions.max() + 1 - len(total_input_ids[i])
)
mrope_position_deltas = torch.tensor(
mrope_position_deltas, device=input_ids.device
).unsqueeze(1)
return position_ids, mrope_position_deltas
else:
if attention_mask is not None:
position_ids = attention_mask.long().cumsum(-1) - 1
position_ids.masked_fill_(attention_mask == 0, 1)
position_ids = (
position_ids.unsqueeze(0)
.expand(3, -1, -1)
.to(attention_mask.device)
)
max_position_ids = position_ids.max(0, keepdim=False)[0].max(
-1, keepdim=True
)[0]
mrope_position_deltas = max_position_ids + 1 - attention_mask.shape[-1]
else:
position_ids = (
torch.arange(input_ids.shape[1], device=input_ids.device)
.view(1, 1, -1)
.expand(3, input_ids.shape[0], -1)
)
mrope_position_deltas = torch.zeros(
[input_ids.shape[0], 1],
device=input_ids.device,
dtype=input_ids.dtype,
)
return position_ids, mrope_position_deltas
_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: dict[str, Any] | None = None,
dtype: torch.dtype | None = 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:
if "rope_type" in rope_scaling:
scaling_type = rope_scaling["rope_type"]
elif "type" in rope_scaling:
scaling_type = rope_scaling["type"]
else:
raise ValueError("Unknown RoPE scaling 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"],
mrope_interleaved=rope_scaling.get("mrope_interleaved", False),
)
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"]
if "alpha" in rope_scaling:
rotary_emb = DynamicNTKAlphaRotaryEmbedding(
head_size,
rotary_dim,
max_position,
base,
is_neox_style,
rope_scaling["alpha"],
dtype,
)
else:
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"]
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