add benchmark (pandas-dev#46193)

Author: Khor Chean Wei

asv_bench/benchmarks/indexing.py

@@ -290,12 +290,24 @@ def setup(self):
         self.dti = dti
         self.dti2 = dti2
 
+        index = np.random.choice(dti, 10000, replace=True)
+        df = DataFrame(index=index, data={"a": 1})
+        df_sort = df.sort_index()
+        self.df = df
+        self.df_sort = df_sort
+
     def time_get_indexer_mismatched_tz(self):
         # reached via e.g.
         #  ser = Series(range(len(dti)), index=dti)
         #  ser[dti2]
         self.dti.get_indexer(self.dti2)
 
+    def time_loc_unsorted(self):
+        self.df.loc["2016-6-11"]
+
+    def time_loc_sorted(self):
+        self.df_sort.loc["2016-6-11"]
+
 
 class CategoricalIndexIndexing: