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FastDeploy/fastdeploy/model_executor/layers/quantization/w4afp8.py
2025-09-05 17:07:58 +08:00

119 lines
3.9 KiB
Python

"""
# Copyright (c) 2025 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.
"""
from typing import Optional
import paddle
import fastdeploy
from ..moe import FusedMoE
from .quant_base import QuantConfigBase, QuantMethodBase
QUANT_SCALING_FACTOR = 448
class W4AFP8Config(QuantConfigBase):
"""
quantization config for weight 4bits and activation fp8
"""
def __init__(self, weight_scale_dict, act_scale_dict, is_permuted, hadamard_block_size) -> None:
super().__init__()
self.weight_scale_dict = weight_scale_dict
self.act_scale_dict = act_scale_dict
self.quant_max_bound = 448
self.quant_min_bound = -448
self.quant_round_type = 1
self.is_permuted = is_permuted
self.hadamard_block_size = hadamard_block_size
def name(self) -> str:
return "w4afp8"
@classmethod
def from_config(cls, config: dict) -> "W4AFP8Config":
weight_scale_dict = config.get("weight_scale_dict", None)
act_scale_dict = config.get("act_scale_dict", None)
is_permuted = config.get("is_permuted", True)
hadamard_block_size = config.get("hadamard_block_size", 128)
return cls(weight_scale_dict, act_scale_dict, is_permuted, hadamard_block_size)
def get_quant_method(self, layer) -> Optional[QuantMethodBase]:
if isinstance(layer, FusedMoE):
from fastdeploy.model_executor.layers.moe.fused_moe_cutlass_backend import (
CutlassW4AFP8MoEMethod,
)
return CutlassW4AFP8MoEMethod(self)
return W4AFP8LinearMethod(self)
class W4AFP8LinearMethod(QuantMethodBase):
"""
W4 AFP8 quant method for linear
"""
def __init__(
self,
quant_config: W4AFP8Config,
) -> None:
super().__init__()
self.quant_config = quant_config
def create_weights(self, layer, **extra_weight_attrs):
layer.weight_shape.reverse()
layer.weight_shape[0] //= 2
layer.weight_dtype = "int8"
layer.weight = layer.create_parameter(
shape=layer.weight_shape,
dtype=layer.weight_dtype,
is_bias=False,
default_initializer=paddle.nn.initializer.Constant(0),
)
def process_loaded_weights(self, layer, weights) -> None:
(
quanted_weight_tensor,
weight_scale_tensor,
) = fastdeploy.model_executor.ops.gpu.scaled_gemm_f8_i4_f16_weight_quantize(
paddle.cast(weights, "float32").cpu(),
groupsize=-1,
scale_dtype="float16",
)
weight_scale_tensor = paddle.view(weight_scale_tensor, layer._dtype)
layer.weight.set_value(quanted_weight_tensor)
layer.weight_scale.set_value(weight_scale_tensor)
def apply(self, layer, x):
linear_out = fastdeploy.model_executor.ops.gpu.scaled_gemm_f8_i4_f16(
x,
layer.weight,
layer.weight_scale,
zero_points=None,
bias=layer.bias if layer.add_bias else None,
out_scale=self.quant_config.weight_scale_dict.get(layer.prefix + ".weight_scale")
/ (
self.quant_config.act_scale_dict.get(layer.prefix + ".activation_scale")
* QUANT_SCALING_FACTOR
* QUANT_SCALING_FACTOR
),
groupsize=0,
out_dtype=layer._dtype,
)
return linear_out