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2025-09-15 14:58:11 +08:00

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Python

# SPDX-License-Identifier: Apache-2.0
from math import prod
from typing import List, Optional, Tuple
import torch
from vllm import _custom_ops as ops
from vllm.model_executor.layers.quantization.utils.fp8_utils import (
per_token_group_quant_fp8)
from vllm.utils import cdiv
def _resize_cache(x: torch.Tensor, v: Tuple[int, ...]) -> torch.Tensor:
"""
Shrink the given tensor and apply the given view to it. This is
used to resize the intermediate fused_moe caches.
"""
assert prod(v) <= x.numel()
return x.flatten()[:prod(v)].view(*v)
def _fp8_quantize(
A: torch.Tensor,
A_scale: Optional[torch.Tensor],
block_shape: Optional[List[int]],
) -> Tuple[torch.Tensor, torch.Tensor]:
"""
Perform fp8 quantization on the inputs. If a block_shape
is provided, the output will be blocked.
"""
if block_shape is None:
A, A_scale = ops.scaled_fp8_quant(A, A_scale)
else:
assert len(block_shape) == 2
_, block_k = block_shape[0], block_shape[1]
A, A_scale = per_token_group_quant_fp8(A, block_k)
assert cdiv(A.shape[-1], block_k) == A_scale.shape[-1]
return A, A_scale
def _fp8_perm(m: torch.Tensor, idx: torch.Tensor) -> torch.Tensor:
"""
A permutation routine that works on fp8 types.
"""
if torch.is_floating_point(m) and torch.finfo(m.dtype).bits == 8:
return m.view(dtype=torch.uint8)[idx, ...].view(dtype=m.dtype)
else:
return m[idx, ...]