!6207 [MSLITE] weight quant fix

Merge pull request !6207 from wangchangkai/master

mindspore/lite/tools/converter/quantizer/weight_quantizer.cc

@@ -58,13 +58,21 @@ STATUS WeightQuantizer::DoConvQuantize(const std::list<CNodePtr> &nodes) {
       return RET_ERROR;
     }
 
+    ParamValueLitePtr param_value = std::static_pointer_cast<ParamValueLite>(param_node->default_param());
+    if (param_value == nullptr) {
+      return RET_ERROR;
+    }
+    if (param_value->tensor_type() != mindspore::kNumberTypeFloat32) {
+      MS_LOG(ERROR) << "model weight data type invalid which is " << param_value->tensor_type();
+      return RET_ERROR;
+    }
+
     std::vector<schema::QuantParamT> quant_params;
     primitive_c->AddInputQuantParam(quant_params);
 
     auto op_type = (schema::PrimitiveType)primitive_c->Type();
     bool depthwise = op_type == schema::PrimitiveType_DepthwiseConv2D ? true : false;
 
-    ParamValueLitePtr param_value = std::static_pointer_cast<ParamValueLite>(param_node->default_param());
     auto status =
       QuantFilter<int8_t>(param_value, primitive_c, QuantType_WeightQuant,
         quant_max, quant_min, bitNum, true, depthwise);