[dynamo] Fix issue with namedtuple slicing (#163351)

Fixes #163253

Pull Request resolved: https://github.com/pytorch/pytorch/pull/163351
Approved by: https://github.com/williamwen42, https://github.com/mlazos

test/inductor/test_cpu_repro.py

@@ -128,6 +128,20 @@ class LstmModule(torch.nn.Module):
 class CPUReproTests(TestCase):
     common = check_model
 
+    def test_torch_linalg_qr_tuple_slice(self):
+        def fn(x):
+            return torch.linalg.qr(x)[:1]
+
+        x = torch.randn(4, 4)
+        compiled = torch.compile(fn, backend="inductor")
+
+        expected = fn(x)
+        actual = compiled(x)
+
+        self.assertIsInstance(actual, tuple)
+        self.assertEqual(len(actual), 1)
+        torch.testing.assert_close(actual[0], expected[0])
+
     @skipIfRocm
     def test_conv_stride_constraints(self):
         for fmt in [torch.contiguous_format, torch.channels_last]:

torch/_dynamo/variables/lists.py

@@ -1317,6 +1317,15 @@ class NamedTupleVariable(TupleVariable):
 
         return super().call_method(tx, name, args, kwargs)
 
+    def getitem_const(self, tx: "InstructionTranslator", arg: VariableTracker):
+        if isinstance(arg, SliceVariable):
+            # slicing a namedtuple produces a tuple
+            return TupleVariable(
+                self.items[arg.as_python_constant()],
+                source=None,
+            )
+        return super().getitem_const(tx, arg)
+
     def var_getattr(self, tx: "InstructionTranslator", name):
         def check_and_create_method():
             method = inspect.getattr_static(self.tuple_cls, name, None)