Fix the problem that the quantization model cannot find the weight (#49664)

python/paddle/static/quantization/quantization_pass.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import collections
+import logging
 
 import numpy as np
 
@@ -27,6 +28,7 @@ from ...fluid.framework import IrGraph, IrNode
 from ...framework import _get_paddle_place, core
 from ...static import Program, data, program_guard, scope_guard
 from ...utils import unique_name
+from ..log_helper import get_logger
 from . import utils
 from .quant_config import (
     SUPPORT_ACT_QUANTIZATION_OP_DICT,
@@ -34,6 +36,10 @@ from .quant_config import (
     SUPPORT_WEIGHT_QUANTIZATION_OP_DICT,
 )
 
+_logger = get_logger(
+    __name__, logging.INFO, fmt='%(asctime)s-%(levelname)s: %(message)s'
+)
+
 _fake_quant_op_list = [
     'fake_quantize_abs_max',
     'fake_quantize_range_abs_max',
@@ -3193,11 +3199,24 @@ class QuantWeightPass:
                         quantized_param_v = quantized_param_v.astype(
                             save_weight_dtype
                         )
-                    self._restore_var(x_node.name(), quantized_param_v)
+                    quant_weight_node = graph.create_persistable_node(
+                        name=self._quantized_var_name(x_node.name()),
+                        var_type=core.VarDesc.VarType.LOD_TENSOR,
+                        shape=x_node.shape(),
+                        var_dtype=core.VarDesc.VarType.INT8,
+                    )
+                    _init_var_node(
+                        quant_weight_node,
+                        quantized_param_v,
+                        self._scope,
+                        self._place,
+                    )
 
                 for next_op_node in out_node.outputs:
-                    graph.update_input_link(out_node, x_node, next_op_node)
-                graph.safe_remove_nodes(out_node)
+                    graph.update_input_link(
+                        out_node, quant_weight_node, next_op_node
+                    )
+                graph.safe_remove_nodes(_op)
         self._remove_unused_var_nodes(graph)
 
     def _remove_unused_var_nodes(self, graph):
@@ -3222,9 +3241,11 @@ class QuantWeightPass:
     def _load_var(self, name):
         return np.array(self._scope.find_var(name).get_tensor())
 
-    def _restore_var(self, name, array):
-        tensor = self._scope.find_var(name).get_tensor()
-        tensor.set(array, self._place)
+    def _quantized_var_name(self, var_name):
+        """
+        Return quantized variable name for the input `var_name`.
+        """
+        return "%s.quantized" % (var_name)
 
 
 class AddQuantDequantForInferencePass:
@@ -3325,9 +3346,17 @@ class AddQuantDequantForInferencePass:
             var_dtype=var_node.dtype(),
         )
         if not self._calibration_range_dict:
-            scale_var_node = graph._find_node_by_name(
-                graph.all_persistable_nodes(), self._scale_name(var_name)
-            )
+            try:
+                scale_var_node = graph._find_node_by_name(
+                    graph.all_persistable_nodes(), self._scale_name(var_name)
+                )
+            except:
+                _logger.warning(
+                    "Cannot find the target node {} in scope, so skip adding quant node.".format(
+                        var_name
+                    )
+                )
+                return None
         elif var_name in self._calibration_range_dict:
             scale_value = self._calibration_range_dict[var_name]
             scale_var_node = graph.create_persistable_node(