feat(mge/quantization): use extra act_fakequant to decide whether to do bias fakequant

GitOrigin-RevId: bf54012155292a5270db34d49cc5e761776b9ad3

imperative/python/megengine/module/qat/batch_matmul_activation.py

@@ -5,8 +5,6 @@
 # Unless required by applicable law or agreed to in writing,
 # software distributed under the License is distributed on an
 # "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-
-from ...quantization.utils import fake_quant_bias
 from .. import batch_matmul_activation as Float
 from .module import QATModule
 
@@ -18,7 +16,7 @@ class BatchMatMulActivation(Float.BatchMatMulActivation, QATModule):
 
     def forward(self, inp):
         w_qat = self.apply_quant_weight(self.weight)
-        b_qat = fake_quant_bias(self.bias, inp, w_qat)
+        b_qat = self.apply_quant_bias(self.bias, inp, w_qat)
         return self.apply_quant_activation(self._calc_linear(inp, w_qat, b_qat))
 
     @classmethod

imperative/python/megengine/module/qat/conv.py

@@ -6,7 +6,6 @@
 # software distributed under the License is distributed on an
 # "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 from ... import functional as F
-from ...quantization.utils import fake_quant_bias
 from .. import conv as Float
 from .module import QATModule
 
@@ -19,10 +18,7 @@ class Conv2d(Float.Conv2d, QATModule):
 
     def calc_conv_qat(self, inp):
         w_qat = self.apply_quant_weight(self.weight)
-        if self.weight_fake_quant and self.weight_fake_quant.enabled:
-            b_qat = fake_quant_bias(self.bias, inp, w_qat)
-        else:
-            b_qat = self.bias
+        b_qat = self.apply_quant_bias(self.bias, inp, w_qat)
         conv = self.calc_conv(inp, w_qat, b_qat)
         return conv
 

imperative/python/megengine/module/qat/conv_bn.py

@@ -6,7 +6,6 @@
 # software distributed under the License is distributed on an
 # "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 from ...functional import ones, relu, sqrt, sum, zeros
-from ...quantization.utils import fake_quant_bias
 from .. import conv_bn as Float
 from .module import QATModule
 
@@ -122,10 +121,7 @@ class _ConvBnActivation2d(Float._ConvBnActivation2d, QATModule):
             b_fold = beta + gamma * (conv_bias - bn_mean) * bn_istd
 
         w_qat = self.apply_quant_weight(w_fold)
-        if self.weight_fake_quant and self.weight_fake_quant.enabled:
-            b_qat = fake_quant_bias(b_fold, inp, w_qat)
-        else:
-            b_qat = b_fold
+        b_qat = self.apply_quant_bias(b_fold, inp, w_qat)
         conv = self.conv.calc_conv(inp, w_qat, b_qat)
         if not (self.training and approx):
             return conv

imperative/python/megengine/module/qat/linear.py

@@ -5,7 +5,6 @@
 # Unless required by applicable law or agreed to in writing,
 # software distributed under the License is distributed on an
 # "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-from ...quantization.utils import fake_quant_bias
 from .. import linear as Float
 from .module import QATModule
 
@@ -22,13 +21,10 @@ class Linear(Float.Linear, QATModule):
 
     """
 
-    def forward(self, x):
+    def forward(self, inp):
         w_qat = self.apply_quant_weight(self.weight)
-        if self.weight_fake_quant and self.weight_fake_quant.enabled:
-            b_qat = fake_quant_bias(self.bias, x, w_qat)
-        else:
-            b_qat = self.bias
-        return self.apply_quant_activation(self._calc_linear(x, w_qat, b_qat))
+        b_qat = self.apply_quant_bias(self.bias, inp, w_qat)
+        return self.apply_quant_activation(self._calc_linear(inp, w_qat, b_qat))
 
     @classmethod
     def from_float_module(cls, float_module: Float.Linear):

imperative/python/megengine/module/qat/module.py

@@ -11,6 +11,7 @@ from abc import abstractmethod
 from ...quantization.fake_quant import FakeQuantize
 from ...quantization.observer import Observer
 from ...quantization.qconfig import QConfig
+from ...quantization.utils import fake_quant_bias
 from ...tensor import Tensor
 from ..module import Module
 
@@ -107,6 +108,24 @@ class QATModule(Module):
             target, self.act_fake_quant, self.act_observer
         )
 
+    def apply_quant_bias(self, target: Tensor, inp: Tensor, w_qat: Tensor):
+        r"""
+        Use :func:`~.fake_quant_bias` to process ``target``. Only valid when
+        ``act_fake_quant`` and ``weight_fake_quant`` are both enabled.
+        """
+        # bias should have the same dtype as activation, so act_fake_quant can also
+        # decide whether to do bias fakequant
+        if (
+            self.act_fake_quant
+            and self.act_fake_quant.enabled
+            and self.weight_fake_quant
+            and self.weight_fake_quant.enabled
+        ):
+            b_qat = fake_quant_bias(target, inp, w_qat)
+        else:
+            b_qat = target
+        return b_qat
+
     def _get_method_result(
         self, method: str, fake_quant: FakeQuantize, observer: Observer
     ):

imperative/python/megengine/quantization/__init__.py

@@ -30,4 +30,10 @@ from .quantize import (
     quantize_qat,
     reset_qconfig,
 )
-from .utils import QParams, QuantMode, create_qparams
+from .utils import (
+    QParams,
+    QuantMode,
+    create_qparams,
+    fake_quant_bias,
+    fake_quant_tensor,
+)