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xc-llm-ascend/vllm_ascend/quantization/w8a8.py
yiz-liu a73bd6caf4 [Fix] Set div_mode to False and fix view_as position (#912)
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Set div_mode to False to use the ACLNN kernel, which is crucial when
using ACL Graph.

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Signed-off-by: Yizhou Liu <liu_yizhou@outlook.com>
2025-05-22 09:57:25 +08:00

115 lines
4.2 KiB
Python

#
# Copyright (c) 2025 Huawei Technologies Co., Ltd. All Rights Reserved.
# This file is a part of the vllm-ascend project.
#
# 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.
#
from typing import Any, Dict, Optional
import torch
import torch_npu
def quant_per_tensor(in_tensor: torch.Tensor, input_scale: torch.Tensor,
input_offset: torch.Tensor):
return torch_npu.npu_quantize(in_tensor, input_scale, input_offset,
torch.qint8, -1, False)
class AscendW8A8LinearMethod:
"""Linear method for Ascend W8A8.
Args:
w_sym: whether the linear weight is symmetrically quantized.
"""
def __init__(self) -> None:
# aclnn quant matmul requires to transpose matrix B, set to true by default.
self.transpose_weight = True
@staticmethod
def get_weight(
input_size: int,
output_size: int,
params_dtype: torch.dtype = torch.bfloat16,
) -> Dict[str, Any]:
params_dict = {
"weight": torch.empty(output_size, input_size, dtype=torch.int8)
}
return params_dict
@staticmethod
def get_pertensor_param(params_dtype: torch.dtype) -> Dict[str, Any]:
params_dict = {}
params_dict["input_scale"] = torch.empty(1, dtype=params_dtype)
params_dict["input_offset"] = torch.empty(1, dtype=torch.int8)
return params_dict
@staticmethod
def get_perchannel_param(
output_size: int,
params_dtype: torch.dtype,
) -> Dict[str, Any]:
params_dict = {}
params_dict["quant_bias"] = torch.empty(output_size, dtype=torch.int32)
if params_dtype == torch.bfloat16:
params_dict["deq_scale"] = torch.empty(output_size,
dtype=torch.float32)
elif params_dtype == torch.float16:
params_dict["deq_scale"] = torch.empty(output_size,
dtype=torch.int64)
params_dict["weight_scale"] = torch.empty(output_size,
1,
dtype=params_dtype)
params_dict["weight_offset"] = torch.empty(output_size,
1,
dtype=params_dtype)
return params_dict
@staticmethod
def apply(
layer: torch.nn.Module,
x: torch.Tensor,
bias: Optional[torch.Tensor] = None,
tp_rank: Optional[int] = 0,
) -> torch.Tensor:
original_dtype = x.dtype
if original_dtype != torch.int8:
x = quant_per_tensor(
x,
layer.aclnn_input_scale,
layer.aclnn_input_offset,
)
quant_bias = layer.quant_bias if tp_rank == 0 else None
return torch_npu.npu_quant_matmul(
x,
layer.weight,
layer.deq_scale,
bias=quant_bias,
output_dtype=original_dtype,
)
def process_weights_after_loading(self, layer):
expanding_factor = layer.weight.data.shape[1]
layer.aclnn_input_scale = 1 / torch.nn.Parameter(
layer.input_scale.data.repeat(expanding_factor),
requires_grad=False)
layer.aclnn_input_offset = torch.nn.Parameter(
layer.input_offset.data.repeat(expanding_factor),
requires_grad=False).to(layer.aclnn_input_scale.dtype)
if self.transpose_weight:
layer.weight.data = layer.weight.data.transpose(0, 1).contiguous()
layer.weight_scale.data = torch.flatten(layer.weight_scale.data)
layer.weight_offset.data = torch.flatten(layer.weight_offset.data)