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paddlepaddle--paddle/python/paddle/quantization/observers/abs_max.py
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2026-07-13 12:40:42 +08:00

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Python

# Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
#
# 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 paddle
from ..base_observer import BaseObserver
from ..factory import ObserverFactory
class AbsmaxObserver(ObserverFactory):
r"""
It collects maximum absolute values of target tensor.
Args:
bit_length(int, optional): Number of bits to represent an quantized integer in binary.
dtype(str, optional): The data type of input tensor.
name (str, optional): This parameter is used by developers to print debugging information. \
For details, please refer to :ref:`api_guide_Name`. Default is None.
Examples:
.. code-block:: pycon
>>> from paddle.quantization import QuantConfig
>>> from paddle.quantization.quanters import FakeQuanterWithAbsMaxObserver
>>> quanter = FakeQuanterWithAbsMaxObserver(moving_rate=0.99)
>>> q_config = QuantConfig(activation=quanter, weight=quanter)
"""
def __init__(self, quant_bits=8):
super().__init__(quant_bits=quant_bits)
def _get_class(self):
return AbsmaxObserverLayer
class AbsmaxObserverLayer(BaseObserver):
"""
Per-tensor abs max quantizer.
"""
INIT_ABS_MAX = 1e-7
def __init__(self, layer, quant_bits=8):
super().__init__()
self._quant_bits = quant_bits
self.abs_max_val = paddle.to_tensor(AbsmaxObserverLayer.INIT_ABS_MAX)
self._max = None
self._scale = None
self._zero_point = None
def forward(self, input):
self._min, self._max = self.cal_min_max(input)
return input
def cal_min_max(self, inputs):
abs_max_val = paddle.max(paddle.abs(inputs))
if self._max is not None:
abs_max_val = paddle.maximum(
abs_max_val, self._max.cast(inputs.dtype)
)
return 0, abs_max_val
def bit_length(self):
return self._quant_bits
def quant_axis(self):
return -1
def cal_thresholds(self):
"""Compute thresholds for MAX function."""
if self._scale is None:
self._scale = self._max
self._zero_point = paddle.zeros_like(self._scale)
def scales(self):
"""Return output scales."""
if self._scale is None:
self.cal_thresholds()
return self._scale
def zero_points(self):
"""Return output zero points."""
return self._zero_point