From e5d866bc68c4762ebd6e3e888e4abeaf4ccd9302 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 26 Feb 2025 07:01:27 -0800
Subject: [PATCH] Short circuit Index.equal if compared Index isn't same type
 (#18067)

closes https://github.com/rapidsai/cudf/issues/8689

Before, comparing two different Index subclasses would execute a GPU kernel when we know they wouldn't be equal (e.g. DatetimeIndex equals RangeIndex). This PR add a short circuit clause to check that we are comparing the same subclasses.

Also ensures we don't return a `np.bool_` object from this result.

Authors:
  - Matthew Roeschke (https://github.com/mroeschke)

Approvers:
  - GALI PREM SAGAR (https://github.com/galipremsagar)

URL: https://github.com/rapidsai/cudf/pull/18067
---
 python/cudf/cudf/core/column/column.py | 2 +-
 python/cudf/cudf/core/index.py         | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/python/cudf/cudf/core/column/column.py b/python/cudf/cudf/core/column/column.py
index 06dc4058115..67a0aa7a781 100644
--- a/python/cudf/cudf/core/column/column.py
+++ b/python/cudf/cudf/core/column/column.py
@@ -713,7 +713,7 @@ def all(self, skipna: bool = True) -> bool:
         # is empty.
         if self.null_count == self.size:
             return True
-        return self.reduce("all")
+        return bool(self.reduce("all"))
 
     def any(self, skipna: bool = True) -> bool:
         # Early exit for fast cases.
diff --git a/python/cudf/cudf/core/index.py b/python/cudf/cudf/core/index.py
index 1730a692dc1..f4e5f6e96ae 100644
--- a/python/cudf/cudf/core/index.py
+++ b/python/cudf/cudf/core/index.py
@@ -1286,6 +1286,15 @@ def equals(self, other) -> bool:
         elif other_is_categorical and not self_is_categorical:
             self = self.astype(other.dtype)
             check_dtypes = True
+        elif (
+            not self_is_categorical
+            and not other_is_categorical
+            and not isinstance(other, RangeIndex)
+            and not isinstance(self, type(other))
+        ):
+            # Can compare Index to CategoricalIndex or RangeIndex
+            # Other comparisons are invalid
+            return False
 
         try:
             return self._column.equals(