message: Emit error message when bias cannot be quantized properly. This is preferred over runtime fails.
diff: @@ -1045,6 +1045,18 @@ TfLiteStatus QuantizeBiases(ModelT* model,
  weight_property.per_axis, weight_property.per_axis_index,
  activations_type, error_reporter));
  }
  + } else {
  + // If bias is already quantized, make sure it is quantized to 32 bit.
  + if (bias_tensor->type != TensorType_INT32) {
  + TF_LITE_REPORT_ERROR(
  + error_reporter,
  + "Bias (\"%s\" at global index %d) of op \"%s\" at op_index %d "
  + "in subgraph %d is expected to be quantized to INT32 but it is "
  + "already quantized to %s.\n",
  + bias_tensor->name.c_str(), op->inputs[bias_idx],
  + operator_name.c_str(), op_idx, subgraph_idx,
  + EnumNameTensorType(bias_tensor->type));
  + }
  }
  }
  }
  