43
vllm_ascend/_310p/ops/fla/l2norm.py
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43
vllm_ascend/_310p/ops/fla/l2norm.py
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@@ -0,0 +1,43 @@
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#
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# Copyright (c) 2026 Huawei Technologies Co., Ltd. All Rights Reserved.
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# This file is a part of the vllm-ascend project.
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#
|
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# Licensed under the Apache License, Version 2.0 (the "License");
|
||||
# you may not use this file except in compliance with the License.
|
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# 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.
|
||||
# mypy: ignore-errors
|
||||
|
||||
from __future__ import annotations
|
||||
|
||||
import math
|
||||
|
||||
import torch
|
||||
import torch_npu
|
||||
from vllm.model_executor.layers.fla.ops.utils import tensor_cache
|
||||
|
||||
|
||||
@tensor_cache
|
||||
def _l2norm_unit_weight(dim: int, dtype: torch.dtype, device: torch.device) -> torch.Tensor:
|
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# RMSNorm with weight 1/sqrt(dim) matches L2 norm: x / sqrt(sum(x^2)).
|
||||
return torch.full((dim,), 1.0 / math.sqrt(dim), dtype=dtype, device=device)
|
||||
|
||||
|
||||
def l2norm_310p(x: torch.Tensor, eps: float = 1e-6) -> torch.Tensor:
|
||||
"""L2-normalize the last dimension using the 310P NPU RMSNorm kernel."""
|
||||
orig_shape = x.shape
|
||||
dim = x.shape[-1]
|
||||
x_2d = x.reshape(-1, dim).contiguous()
|
||||
weight = _l2norm_unit_weight(dim, x.dtype, x.device)
|
||||
# RMSNorm: y = x / sqrt(mean(x^2) + eps_rms) * weight
|
||||
# With weight=1/sqrt(dim), this equals x / sqrt(sum(x^2) + dim * eps_rms).
|
||||
# L2 norm needs y = x / sqrt(sum(x^2) + eps), so eps_rms = eps / dim.
|
||||
y, _ = torch_npu.npu_rms_norm(x_2d, weight, eps / dim)
|
||||
return y.reshape(orig_shape)
|
||||
Reference in New Issue
Block a user