Remove duplicate user fusion config and Clean up stale imports

backends/arm/_passes/arm_pass_manager.py

@@ -150,7 +150,6 @@
 from executorch.backends.arm.common.arm_compile_spec import ArmCompileSpec
 from executorch.backends.arm.common.pipeline_config import (
     ArmPassPipelineConfig,
-    FuseDuplicateUsersConfig,
     SoftmaxDecompositionConfig,
 )
 from executorch.backends.arm.tosa.specification import (
@@ -238,9 +237,6 @@ def configure_skip_passes(
             case SoftmaxDecompositionConfig.STABLE:
                 skip_set.add(DecomposeMaskedFillPass)
 
-        if config.fuse_duplicate_users is FuseDuplicateUsersConfig.DISABLED:
-            skip_set.add(FuseDuplicateUsersPass)
-
         self._skip_pass_types = tuple(skip_set)
         skip_names = [skipped_pass.__name__ for skipped_pass in self._skip_pass_types]
         logger.debug(f"Passes in skip list: {skip_names}")

backends/arm/common/pipeline_config.py

@@ -14,24 +14,12 @@ class SoftmaxDecompositionConfig(Enum):
     STABLE = auto()  # Stable softmax, no masked fill decomposition
 
 
-class FuseDuplicateUsersConfig(Enum):
-    ENABLED = auto()
-    DISABLED = auto()
-
-
 @dataclass
 class ArmPassPipelineConfig:
     softmax: SoftmaxDecompositionConfig = SoftmaxDecompositionConfig.MASKED
-    fuse_duplicate_users: FuseDuplicateUsersConfig = FuseDuplicateUsersConfig.ENABLED
-
-    def disable_fuse_duplicate_users(self) -> None:
-        self.fuse_duplicate_users = FuseDuplicateUsersConfig.DISABLED
 
     def is_default(self) -> bool:
-        return (
-            self.softmax is SoftmaxDecompositionConfig.MASKED
-            and self.fuse_duplicate_users is FuseDuplicateUsersConfig.ENABLED
-        )
+        return self.softmax is SoftmaxDecompositionConfig.MASKED
 
     def to_dict(self) -> dict[str, str]:
         return {f.name: getattr(self, f.name).name for f in fields(self)}

backends/arm/test/misc/test_compile_spec.py

@@ -5,10 +5,7 @@
 
 import warnings
 
-from executorch.backends.arm.common.pipeline_config import (
-    FuseDuplicateUsersConfig,
-    SoftmaxDecompositionConfig,
-)
+from executorch.backends.arm.common.pipeline_config import SoftmaxDecompositionConfig
 from executorch.backends.arm.ethosu import EthosUCompileSpec
 from executorch.backends.arm.tosa.compile_spec import TosaCompileSpec
 from executorch.backends.arm.vgf import VgfCompileSpec
@@ -66,11 +63,11 @@ def test_compile_spec_vgf_no_quant():
         EthosUCompileSpec._from_list(spec_list)
 
 
-def test_compile_spec_vgf_defaults_to_enabled_fuse_duplicate_users():
+def test_compile_spec_vgf_uses_default_pipeline_config():
     compile_spec = VgfCompileSpec()
     pipeline_config = compile_spec._get_pass_pipeline_config()
 
-    assert pipeline_config.fuse_duplicate_users == FuseDuplicateUsersConfig.ENABLED
+    assert pipeline_config.is_default()
 
 
 def test_compile_spec_tosa_INT():

backends/arm/test/misc/test_pass_pipeline_config.py

@@ -29,14 +29,13 @@ def test_pipeline_config_override_outside_compile_spec():
     override_compile_spec = TosaCompileSpec(
         TosaSpecification.create_from_string("TOSA-1.00+INT")
     )
-    override_config = ArmPassPipelineConfig()
-    override_config.disable_fuse_duplicate_users()
+    override_config = ArmPassPipelineConfig(softmax=SoftmaxDecompositionConfig.STABLE)
     override_compile_spec.set_pass_pipeline_config(override_config)
     override_manager = ArmPassManager(override_compile_spec)
     skip_passes = override_manager._skip_pass_types
 
-    assert FuseDuplicateUsersPass in skip_passes
-    assert DecomposeSoftmaxPass not in skip_passes
+    assert FuseDuplicateUsersPass not in skip_passes
+    assert DecomposeMaskedFillPass in skip_passes
 
 
 def test_softmax_config_masked_no_target():

backends/arm/test/misc/test_tosa_dialect_conv2d.py

@@ -4,7 +4,7 @@
 # LICENSE file in the root directory of this source tree.
 
 
-import executorch.backends.arm.tosa.dialect  # noqa: unused
+import executorch.backends.arm.tosa.dialect  # noqa: F401
 import pytest
 import torch
 from executorch.backends.arm.tosa.dialect.lib import TosaValueError

backends/arm/test/misc/test_tosa_dialect_dw_conv2d.py

@@ -4,7 +4,7 @@
 # LICENSE file in the root directory of this source tree.
 
 
-import executorch.backends.arm.tosa.dialect  # noqa: unused
+import executorch.backends.arm.tosa.dialect  # noqa: F401
 import pytest
 import torch
 from executorch.backends.arm.tosa.dialect.lib import TosaValueError

backends/arm/tosa/compile_spec.py

@@ -4,9 +4,6 @@
 # LICENSE file in the root directory of this source tree.
 
 from executorch.backends.arm.common.arm_compile_spec import ArmCompileSpec
-from executorch.backends.arm.common.pipeline_config import (  # noqa: unused
-    ArmPassPipelineConfig,
-)
 from executorch.backends.arm.tosa import TosaSpecification
 
 

backends/arm/vgf/compile_spec.py

@@ -6,9 +6,6 @@
 import logging
 
 from executorch.backends.arm.common.arm_compile_spec import ArmCompileSpec
-from executorch.backends.arm.common.pipeline_config import (  # noqa: unused
-    ArmPassPipelineConfig,
-)
 from executorch.backends.arm.tosa import (  # type: ignore[import-not-found]
     TosaSpecification,
 )