Remove RemoveRedundantViewCopyPass (pytorch#2464)

Summary:

The RemoveRedundantViewCopyPass is unnecessary and can be replaced by NormalizeViewCopyBasePass + dead code elimintation.

Differential Revision: D54866523

Author: metascroy

exir/passes/TARGETS

@@ -14,10 +14,10 @@ python_library(
         ":memory_format_ops_pass",
         ":memory_planning_pass",
         ":normalize_transpose_pass",
+        ":normalize_view_copy_base_pass",
         ":prim_ops_py_registry",
         ":quant_fusion_pass",
         ":remove_noop_pass",
-        ":remove_redundant_view_copy_pass",
         ":replace_aten_with_edge_pass",
         ":replace_broken_ops_with_function_ops_pass",
         ":replace_edge_with_backend_pass",
@@ -302,17 +302,6 @@ python_library(
     ],
 )
 
-python_library(
-    name = "remove_redundant_view_copy_pass",
-    srcs = [
-        "remove_redundant_view_copy_pass.py",
-    ],
-    deps = [
-        "//caffe2:torch",
-        "//executorch/exir/dialects:lib",
-    ],
-)
-
 python_library(
     name = "normalize_view_copy_base_pass",
     srcs = [

exir/passes/__init__.py

@@ -42,11 +42,11 @@
 from executorch.exir.passes.memory_format_ops_pass import MemoryFormatOpsPass
 from executorch.exir.passes.memory_planning_pass import MemoryPlanningPass
 from executorch.exir.passes.normalize_transpose_pass import NormalizeTransposePass
+from executorch.exir.passes.normalize_view_copy_base_pass import (
+    NormalizeViewCopyBasePass,
+)
 from executorch.exir.passes.quant_fusion_pass import QuantFusionPass
 from executorch.exir.passes.remove_noop_pass import RemoveNoopPass
-from executorch.exir.passes.remove_redundant_view_copy_pass import (
-    RemoveRedundantViewCopyPass,
-)
 from executorch.exir.passes.replace_aten_with_edge_pass import OpReplacePass
 from executorch.exir.passes.replace_broken_ops_with_function_ops_pass import (
     ReplaceBrokenOpsWithFunctionalOpsPass,
@@ -485,7 +485,9 @@ def dead_code_elimination_pass(graph_module: torch.fx.GraphModule) -> PassResult
         ScalarToTensorPass(),
         SymToTensorPass(),
         RemoveNoopPass(),
-        RemoveRedundantViewCopyPass(),
+        # Running NormalizeViewCopyBasePass + dead code elimination
+        # removes redundant view_copy nodes
+        NormalizeViewCopyBasePass(),
     ]
 ).passes
 

exir/passes/normalize_view_copy_base_pass.py

@@ -29,8 +29,6 @@ class NormalizeViewCopyBasePass(PassBase):
 
     When combined with dead-code elimination, this pass removes redundant
     view_copy nodes.
-
-    TODO: replace RemoveRedundantViewCopyPass with NormalizeViewCopyBasePass + dead code elimination.
     """
 
     def call(self, graph_module: torch.fx.GraphModule) -> PassResult:

exir/passes/remove_redundant_view_copy_pass.py

@@ -1254,6 +1254,11 @@ def forward(self, x):
         self.assertEqual(count_copies(gm), 1)
 
     def test_remove_redundant_view_copy_pass(self) -> None:
+        # This tests that redundant view_copy nodes are removed
+        # during to_edge.  There is no pass that explicitly does this.
+        # It results from running the NormalizeViewCopyBasePass and dead code
+        # elimination.
+
         def is_view(node: torch.fx.Node) -> bool:
             return node.op == "call_function" and node.target in (
                 torch.ops.aten.view_copy.default,
@@ -1271,7 +1276,7 @@ def forward(self, x):
 
         view_chain = ViewChain()
 
-        exported_program = export(view_chain, (torch.ones(30),))
+        exported_program = torch.export.export(view_chain, (torch.ones(30),))
         n_views_before = 0
         for node in exported_program.graph.nodes:
             if is_view(node):