Arm backend: Add docstrings for operator_support/right_shift_support.py (pytorch#14430)

Signed-off-by: Sebastian Larsson <[email protected]>

Author: Sebastian-Larsson

backends/arm/operator_support/right_shift_support.py

@@ -2,6 +2,12 @@
 #
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
+"""Declare operator support for bitwise right-shift in TOSA.
+
+Provide support checks for ``aten.bitwise_right_shift`` and ``__rshift__``
+targets across integer and float TOSA profiles.
+
+"""
 
 # pyre-unsafe
 
@@ -21,6 +27,8 @@
 
 @register_tosa_support_check
 class RightShiftSupported(SupportedTOSAOperatorCheck):
+    """Provide TOSA support check for right-shift operations."""
+
     targets = [
         exir_ops.edge.aten.bitwise_right_shift.Tensor,
         exir_ops.edge.aten.__rshift__.Scalar,
@@ -31,8 +39,15 @@ class RightShiftSupported(SupportedTOSAOperatorCheck):
         TosaSpecification.create_from_string("TOSA-1.0+FP"),
     ]
 
-    def is_node_tosa_supported(self, node: fx.Node, tosa_spec: TosaSpecification):
+    def is_node_tosa_supported(
+        self, node: fx.Node, tosa_spec: TosaSpecification
+    ) -> bool:
+        """Return True if the node is supported by TOSA.
+
+        Emit a warning on U55 subsets where one-off errors may occur. Otherwise
+        accept all matching targets.
 
+        """
         # TODO MLETORCH-525 Remove warning
         if tosa_spec.is_U55_subset:
             logging.warning(f"{node.target} may introduce one-off errors.")