update the code comments

Signed-off-by: Bangtian Liu <[email protected]>

tuner/tuner/libtuner.py

@@ -881,9 +881,13 @@ def calculate_speedup(
         Speedup is defined as the ratio of the candidate's runtime to the average baseline time
         for the corresponding device as:
 
-            speedup = candidate_runtime / avg_baseline_time
+            speedup = candidate_runtime / avg_baseline_time (or fallback_baseline)
 
-        If no valid baseline times are available, the candidate'sruntime is used directly as:
+        If no valid baseline times are available for a specific device, the fallback baseline is used.
+        The fallback baseline is calculated as the average of all valid baseline times across devices.
+
+        If no valid baseline times are available across all devices, the candidate's runtime is
+        used directly as:
 
             speedup = candidate_runtime
 
@@ -909,13 +913,15 @@ def calculate_speedup(
 
         speedup_by_candidate = {}
         for candidate in candidate_results:
-            baseline_avg = self.get_average_result_ms(candidate.device_id)
-            if baseline_avg is None or not math.isfinite(baseline_avg):
-                baseline_avg = fallback_baseline
-            speedup_by_candidate[candidate.candidate_id] = candidate.time / baseline_avg
+            baseline_avg_ms = self.get_average_result_ms(candidate.device_id)
+            if baseline_avg_ms is None:
+                baseline_avg_ms = fallback_baseline
+            speedup_by_candidate[candidate.candidate_id] = (
+                candidate.time / baseline_avg_ms
+            )
         return speedup_by_candidate
 
-    def get_top_candidates(
+    def sort_candidates_with_speedup(
         self,
         speedup_by_candidate: dict[int, float],
     ) -> list[tuple[int, float]]:
@@ -1054,7 +1060,9 @@ def benchmark(
         logging.warning("Baseline run failed.")
 
     speedup_result = baseline_handler.calculate_speedup(candidate_results)
-    all_candidates_with_speedup = baseline_handler.get_top_candidates(speedup_result)
+    all_candidates_with_speedup = baseline_handler.sort_candidates_with_speedup(
+        speedup_result
+    )
     top_candidates_with_speedup = all_candidates_with_speedup[:num_candidates]
 
     if baseline_handler.is_valid():

tuner/tuner/libtuner_test.py

@@ -268,7 +268,7 @@ def test_baseline_result_handler_speedup():
         4: 0.2 / 0.875,
     }
 
-    all_candidates_with_speedup = handler.get_top_candidates(speedup)
+    all_candidates_with_speedup = handler.sort_candidates_with_speedup(speedup)
     assert all_candidates_with_speedup == [
         (4, 0.2 / 0.875),
         (1, 0.4 / 0.9),
@@ -290,8 +290,7 @@ def test_baseline_result_handler_speedup():
         7: 0.8 / 1.2,
     }
 
-    all_candidates_with_speedup = handler.get_top_candidates(speedup)
-    print(all_candidates_with_speedup)
+    all_candidates_with_speedup = handler.sort_candidates_with_speedup(speedup)
     assert all_candidates_with_speedup == [
         (5, 0.6 / 0.9),
         (7, 0.8 / 1.2),
@@ -307,7 +306,7 @@ def test_baseline_result_handler_speedup():
         6: 0.4,
         7: 0.8,
     }
-    all_candidates_with_speedup = handler.get_top_candidates(speedup)
+    all_candidates_with_speedup = handler.sort_candidates_with_speedup(speedup)
     assert all_candidates_with_speedup == [
         (6, 0.4),
         (5, 0.6),