Fix regression loading dtype (#34409)

* fix regression

* add test for torchao

* expected output

* better fix

src/transformers/modeling_utils.py

@@ -943,13 +943,14 @@ def _load_state_dict_into_meta_model(
         old_param = model
         splits = param_name.split(".")
         for split in splits:
-            old_param = getattr(old_param, split)
+            # We shouldn't hit the default value unless for quant methods like hqq that modifies expected_keys.
-            # Not all the attributes of a module are Parameters/Tensor
+            old_param = getattr(old_param, split, None)
-            if not isinstance(old_param, (torch.nn.Parameter, torch.Tensor)):
-                old_param = None
             if old_param is None:
                 break
 
+        if not isinstance(old_param, (torch.nn.Parameter, torch.Tensor)):
+            old_param = None
+
         if old_param is not None:
             if dtype is None:
                 param = param.to(old_param.dtype)

tests/quantization/torchao_integration/test_torchao.py

@@ -208,6 +208,26 @@ class TorchAoTest(unittest.TestCase):
 
         self.assertEqual(tokenizer.decode(output[0], skip_special_tokens=True), EXPECTED_OUTPUT)
 
+    def test_int8_dynamic_activation_int8_weight_quant(self):
+        """
+        Simple LLM model testing int8_dynamic_activation_int8_weight
+        """
+        quant_config = TorchAoConfig("int8_dynamic_activation_int8_weight")
+
+        # Note: we quantize the bfloat16 model on the fly to int4
+        quantized_model = AutoModelForCausalLM.from_pretrained(
+            self.model_name,
+            device_map=torch_device,
+            quantization_config=quant_config,
+        )
+        tokenizer = AutoTokenizer.from_pretrained(self.model_name)
+
+        input_ids = tokenizer(self.input_text, return_tensors="pt").to(torch_device)
+
+        output = quantized_model.generate(**input_ids, max_new_tokens=self.max_new_tokens)
+        EXPECTED_OUTPUT = "What are we having for dinner?\n\nJessica: (smiling)"
+        self.assertEqual(tokenizer.decode(output[0], skip_special_tokens=True), EXPECTED_OUTPUT)
+
 
 if __name__ == "__main__":
     unittest.main()