update SmoothQuant algorithm with folding choice (#799)

Signed-off-by: Xin He <xin3.he@intel.com>
Co-authored-by: wenhuach21 <wenhua.cheng@intel.com>

examples/pytorch/nlp/huggingface_models/language-modeling/quantization/ptq_static/ipex/smooth_quant/eval_lambada.py

@@ -42,10 +42,10 @@ def evaluate(self, model):
             total += label.size(0)
             hit += (pred == label).sum().item()
             if index % args.log_frequency == 0:
-                print(hit / total)
+                print(hit / total, flush=True)
             index += 1
         acc = hit / total
-        print(acc)
+        print(acc, flush=True)
         return acc
 
 
@@ -145,7 +145,7 @@ def eval_func(model):
     recipes = {}
     if args.sq:
         recipes = {"smooth_quant": True, "smooth_quant_args": {'alpha': args.alpha}}
-    op_type_dict = None
+    op_type_dict = {}
     if args.kl:
         op_type_dict = {'linear': {'activation': {'algorithm': ['kl']}}}
     if args.fallback_add:

neural_compressor/adaptor/onnxrt.py

@@ -152,7 +152,7 @@ def __init__(self, framework_specific_info):
 
         self.optype_statistics = None
 
-    def smooth_quant(self, model, dataloader, iterations, tune_cfg, alpha=0.5,
+    def smooth_quant(self, model, dataloader, iterations, tune_cfg, alpha=0.5, folding=False,
                                     percentile=99.999, op_types=['MatMul', 'Linear', 'Conv'], scales_per_op=True):
         """Get augmented model with smooth quant.
 
@@ -162,6 +162,7 @@ def smooth_quant(self, model, dataloader, iterations, tune_cfg, alpha=0.5,
             iterations: iterations
             tune_cfg: quantization config
             alpha: smooth alpha in SmoothQuant, 1.0 will fallback to SPIQ
+            folding: whether insert mul(False) or just allow foldable layers(True) for SmoothQuant
             percentile:Percentile of calibration to remove outliers
             op_types: The op types whose input tensor will be dumped
             scales_per_op: True, each op will have an individual scale, mainly for accuracy

neural_compressor/adaptor/torch_utils/model_wrapper.py

@@ -0,0 +1,106 @@
+#
+# -*- coding: utf-8 -*-
+#
+# Copyright (c) 2021 Intel Corporation
+#
+# 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.
+
+"""Torch.nn.Module Class Defination."""
+# Note: Do not import this file unless you have already imported torch, 
+# since the model classes inherit torch.nn.Module.
+import torch
+from packaging.version import Version
+
+
+def get_torch_version():
+    try:
+        torch_version = torch.__version__.split('+')[0]
+    except ValueError as e:  # pragma: no cover
+        assert False, 'Got an unknown version of torch: {}'.format(e)
+    version = Version(torch_version)
+    return version
+
+PT_VERSION = get_torch_version().release
+
+
+class QDQLinear(torch.nn.Module):
+    def __init__(self, module, scale, zero_point, dtype):
+        super().__init__()
+        if PT_VERSION < Version("1.13.0").release:
+            import torch.nn.quantized as nnq
+        else:
+            import torch.ao.nn.quantized as nnq
+        self.add_module('quant', nnq.Quantize(scale, zero_point, dtype))
+        self.add_module('dequant', nnq.DeQuantize())
+        self.add_module('module', module)
+        self.qdq_weight()
+
+    def forward(self, X):
+        X = self.quant(X)
+        X = self.dequant(X)
+        X = self.module(X)
+        return X
+
+    def qdq_weight(self):
+        # update weight w/ QDQ
+        from .smooth_quant import quant_dequant_w
+        weith_qdq = quant_dequant_w(self.module)
+        self.module.weight = torch.nn.Parameter(weith_qdq)
+
+
+class SQLinearWrapper(torch.nn.Module):
+    def __init__(self, module, input_scale, input_minmax, dtype=torch.quint8):
+        super().__init__()
+        self.input_scale = input_scale
+        self.dtype = dtype
+        # calculate and only save scale, zero_point to avoid memory usage
+        self.scale, self.zero_point = self._calculate_qparams(input_scale, input_minmax, dtype)
+        self.add_module('sq_linear', module)
+        self.ipex = False  # a flag used for ipex inference
+
+    def forward(self, X):
+        if self.ipex:
+            X = self.sq_linear(X)
+        else:
+            X = torch.mul(X, self.input_scale)
+            X = self.sq_linear(X)
+        return X
+
+    def _calculate_qparams(self, input_scale, input_minmax, dtype=torch.quint8):
+        # calculate scale and zero_point
+        if dtype == torch.quint8:
+            quant_min, quant_max = 0, 255
+        min_val = torch.min(input_minmax[0] * input_scale)
+        max_val = torch.max(input_minmax[1] * input_scale)
+        # work when min_val bigger than zero.
+        min_val_neg = torch.min(min_val, torch.zeros_like(min_val))
+        max_val_pos = torch.max(max_val, torch.zeros_like(max_val))
+        scale = (max_val_pos - min_val_neg) / float(quant_max - quant_min)
+        scale = torch.max(scale, torch.tensor([torch.finfo(torch.float32).eps]))
+        zero_point = quant_min - torch.round(min_val_neg / scale).to(torch.int)
+        zero_point = torch.clamp(zero_point, quant_min, quant_max)
+        return scale, zero_point
+
+    def _get_weight_scale(self):
+        # get weight scale and zero_point
+        from torch.ao.quantization.observer import default_per_channel_weight_observer
+        obs = default_per_channel_weight_observer()
+        obs(self.sq_linear.weight)
+        scale, _ = obs.calculate_qparams()
+        return scale
+
+    def _recover_sq_linear(self):
+        # remove mul and reset sq_linear for ipex inference
+        scale = self.input_scale.view(1, self.input_scale.shape[0])
+        with torch.no_grad():
+            self.sq_linear.weight *= scale