Properly set modified for RemoveNopSliceOrViewOpPass

Summary: Ensure modified is being correctly set for RemoveNopSliceOrViewOpPass

Differential Revision: D85815510

Author: Andrew Grebenisan

backends/cadence/aot/remove_ops.py

@@ -191,6 +191,10 @@ class RemoveNopSliceOrViewOpPass(ExportPass):
     Remove slice ops that are more like views, and view ops that do not change the shape
     """
 
+    def __init__(self) -> None:
+        super().__init__()
+        self._modified = False
+
     def call_operator(
         self,
         op,  # pyre-ignore
@@ -204,6 +208,7 @@ def call_operator(
         }:
             return super().call_operator(op, args, kwargs, meta)
 
+        self._modified = True
         arg0 = cast(ProxyValue, args[0])
         out_shape = meta["val"].shape
 
@@ -214,6 +219,11 @@ def call_operator(
             else super().call_operator(op, args, kwargs, meta)
         )
 
+    def call(self, graph_module: torch.fx.GraphModule) -> PassResult:
+        self._modified = False
+        result = super().call(graph_module)
+        return PassResult(result.graph_module, self._modified)
+
 
 @register_cadence_pass(CadencePassAttribute(opt_level=1))
 class RemoveNopLinalgVectorNormOpPass(ExportPass):

backends/cadence/aot/tests/test_remove_ops_passes.py

@@ -276,9 +276,11 @@ def test_remove_nop_view(self, shape: Tuple[int], new_shape: List[int]) -> None:
         )
         builder.output([view])
         original = builder.get_graph_module()
+        pass_instance = RemoveNopSliceOrViewOpPass()
         graph_after_passes = cast(
-            PassResult, RemoveNopSliceOrViewOpPass()(original)
+            PassResult, pass_instance(original)
         ).graph_module
+        self.assertTrue(pass_instance._modified)
         self.assertEqual(
             count_node(graph_after_passes, exir_ops.edge.aten.view_copy.default), 0
         )
@@ -297,13 +299,34 @@ def test_remove_nop_slice(self) -> None:
         )
         builder.output([slice_])
         original = builder.get_graph_module()
+        pass_instance = RemoveNopSliceOrViewOpPass()
         graph_after_passes = cast(
-            PassResult, RemoveNopSliceOrViewOpPass()(original)
+            PassResult, pass_instance(original)
         ).graph_module
+        self.assertTrue(pass_instance._modified)
         self.assertEqual(
             count_node(graph_after_passes, exir_ops.edge.aten.slice_copy.Tensor), 0
         )
 
+    def test_remove_nop_slice_or_view_not_modified(self) -> None:
+        builder = GraphBuilder()
+        x = builder.placeholder("x", torch.randn(3, 5, dtype=torch.float32))
+        abs_x = builder.call_operator(
+            op=exir_ops.edge.aten.abs.default,
+            args=(x,),
+        )
+        builder.output([abs_x])
+        original = builder.get_graph_module()
+        pass_instance = RemoveNopSliceOrViewOpPass()
+        graph_after_passes = cast(
+            PassResult, pass_instance(original)
+        ).graph_module
+        self.assertFalse(pass_instance._modified)
+        self.assertEqual(
+            count_node(graph_after_passes, exir_ops.edge.aten.abs.default), 1
+        )
+
+
     def test_remove_nop_select_before_view(self) -> None:
         builder = GraphBuilder()
         x = builder.placeholder("x", torch.randn(1, 5, 6, dtype=torch.float32))