sglang_v0.5.2/flashinfer_0.3.1/flashinfer/quantization.py

149 lines
4.8 KiB
Python

"""
Copyright (c) 2024 by FlashInfer team.
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 functools
from typing import Tuple
import torch
from .jit import JitSpec
from .jit import env as jit_env
from .jit import gen_jit_spec
from .utils import register_custom_op, register_fake_op
def gen_quantization_module() -> JitSpec:
return gen_jit_spec(
"quantization",
[
jit_env.FLASHINFER_CSRC_DIR / "quantization.cu",
jit_env.FLASHINFER_CSRC_DIR / "flashinfer_quantization_ops.cu",
],
)
@functools.cache
def get_quantization_module():
return gen_quantization_module().build_and_load()
@register_custom_op("flashinfer::packbits", mutates_args=())
def _packbits(x: torch.Tensor, bitorder: str) -> torch.Tensor:
device = x.device
x = x.to(torch.bool)
y = torch.empty((x.size(0) + 7) // 8, dtype=torch.uint8, device=device)
get_quantization_module().packbits(x, bitorder, y)
return y
@register_fake_op("flashinfer::packbits")
def _fake_packbits(x: torch.Tensor, bitorder: str) -> torch.Tensor:
return torch.empty((x.size(0) + 7) // 8, dtype=torch.uint8, device=x.device)
def packbits(x: torch.Tensor, bitorder: str = "big") -> torch.Tensor:
r"""Pack the elements of a binary-valued array into bits in a uint8 array.
The semantics of this function is the same as `numpy.packbits <https://numpy.org/doc/stable/reference/generated/numpy.packbits.html>`_.
Parameters
----------
x: torch.Tensor
The 1D binary-valued array to pack.
bitorder: str
The bit-order ("bit"/"little") of the output. Default is "big".
Returns
-------
y: torch.Tensor
An uint8 packed array, shape ``((x.size(0) + 7) / 8),)``.
Examples
--------
>>> import torch
>>> from flashinfer import packbits
>>> x = torch.tensor([1, 0, 1, 1, 0, 0, 1, 1], dtype=torch.bool, device="cuda")
>>> x_packed = packbits(x)
>>> list(map(bin, x_packed.tolist()))
['0b10110011']
See Also
--------
segment_packbits
"""
return _packbits(x, bitorder)
def segment_packbits(
x: torch.Tensor, indptr: torch.Tensor, bitorder: str = "big"
) -> Tuple[torch.Tensor, torch.Tensor]:
r"""Pack a batch of binary-valued segments into bits in a uint8 array.
For each segment, the semantics of this function is the same as `numpy.packbits <https://numpy.org/doc/stable/reference/generated/numpy.packbits.html>`_.
Parameters
----------
x: torch.Tensor
The 1D binary-valued array to pack, shape ``(indptr[-1],)``.
indptr: torch.Tensor
The index pointer of each segment in :attr:`x`, shape ``(batch_size + 1,)``.
The i-th segment in :attr:`x` is ``x[indptr[i]:indptr[i+1]]``.
bitorder: str
The bit-order ("bit"/"little") of the output. Default is "big".
Returns
-------
y: torch.Tensor
An uint8 packed array, shape: ``(new_indptr[-1],)``.
The ``y[new_indptr[i]:new_indptr[i+1]]`` contains the packed bits ``x[indptr[i]:indptr[i+1]]``.
new_indptr: torch.Tensor
The new index pointer of each packed segment in :attr:`y`, shape ``(batch_size + 1,)``.
It's guaranteed that ``new_indptr[i+1] - new_indptr[i] == (indptr[i+1] - indptr[i] + 7) // 8``.
Examples
--------
>>> import torch
>>> from flashinfer import segment_packbits
>>> x = torch.tensor([1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 1], dtype=torch.bool, device="cuda")
>>> x_packed, new_indptr = segment_packbits(x, torch.tensor([0, 4, 7, 11], device="cuda"), bitorder="big")
>>> list(map(bin, x_packed.tolist()))
['0b10110000', '0b100000', '0b11010000']
>>> new_indptr
tensor([0, 1, 2, 3], device='cuda:0')
Note
----
``torch.compile`` is not supported for this function because it's data dependent.
See Also
--------
packbits
"""
seglen = indptr[1:] - indptr[:-1]
packed_len = (seglen + 7) // 8
indptr_new = torch.zeros(len(indptr), dtype=indptr.dtype, device=indptr.device)
indptr_new[1:] = torch.cumsum(packed_len, 0)
output_nnzs = indptr_new[-1].item()
device = x.device
indptr = indptr.to(torch.int32)
indptr_new = indptr_new.to(torch.int32)
y = torch.empty(output_nnzs, dtype=torch.uint8, device=device)
get_quantization_module().segment_packbits(x, indptr, indptr_new, bitorder, y)
return y, indptr_new