fix torch.Parameter vals if no pos

frontend/guard_tracker.py

@@ -1896,6 +1896,18 @@ def set_if_inplace_return() -> None:
             # TODO: add map and set correct partial var
             return
         elif is_graph_func(func):
+            if func is operator.getitem:
+                obj_var = self.state.objects.get(args[0])
+                assert obj_var.extract_code_at_start[0]
+                obj_pos = obj_var.extract_code_at_start[0]
+                item_pos = StoreInIndex(obj_pos, id(obj_pos), args[1])
+                self.state.set_partial_var({
+                    -1: [
+                        PartialVar(node=None,
+                                   need_guard_check=False,
+                                   extract_code_at_start=[item_pos])
+                    ]
+                })
             return
         elif len(args) > 0 and isinstance(args[0], torch.nn.ModuleList):
             return

frontend/variables/base.py

@@ -2,7 +2,7 @@
 from abc import abstractmethod
 from typing import Any, TYPE_CHECKING, Optional, Tuple, Iterable, Callable
 from copy import copy
-
+import torch
 from frontend.utils import add_force_graph_break
 
 from ..c_api import get_miss_locals
@@ -90,6 +90,9 @@ def make_output(self, name_in_graph_fn: str, store_pos: StorePos,
             self.make_output_inner(name_in_graph_fn, store_pos, codegen,
                                    in_return, idx)
             for attr, var in self.modified_attrs.items():
+                if isinstance(var.obj, torch.nn.Parameter) and len(
+                        var.extract_code_at_start) == 0:
+                    continue
                 var.make_output(f'{name_in_graph_fn}_dot_{attr}',
                                 StoreInAttr(store_pos, id(self.obj), attr),
                                 codegen, False, id(getattr(self.obj, attr)))