perf(pathfinder): fast-path exact directory searches

Signed-off-by: Kevin Turcios <turcioskevinr@gmail.com>

Author: KRRT7

cuda_pathfinder/cuda/pathfinder/_utils/find_sub_dirs.py

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2024-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 import functools
@@ -9,6 +9,14 @@
 
 
 def find_sub_dirs_no_cache(parent_dirs: Sequence[str], sub_dirs: Sequence[str]) -> list[str]:
+    if "*" not in sub_dirs:
+        results = []
+        for base in parent_dirs:
+            candidate = os.path.join(base, *sub_dirs)
+            if os.path.isdir(candidate):
+                results.append(candidate)
+        return results
+
     results = []
     for base in parent_dirs:
         stack = [(base, 0)]  # (current_path, index into sub_dirs)