Benchmark results and TODOs added / updated

EvenPerfectBitScanner.Benchmarks/Mod128ULongBenchmarks.cs

@@ -8,23 +8,49 @@ namespace EvenPerfectBitScanner.Benchmarks;
 [MemoryDiagnoser]
 public class Mod128ULongBenchmarks
 {
-    [Params(3UL, 5UL, 6UL, 8UL, 10UL, 11UL, 32UL, 64UL, 128UL, 256UL, 2_047UL, 8_191UL, 65_535UL, 131_071UL, 2_147_483_647UL, uint.MaxValue - 1_024UL, uint.MaxValue - 511UL, uint.MaxValue - 255UL, uint.MaxValue - 127UL, uint.MaxValue - 63UL, uint.MaxValue - 31UL, uint.MaxValue - 17UL, uint.MaxValue)]
+    [Params(
+        3UL,
+        5UL,
+        6UL,
+        8UL,
+        10UL,
+        11UL,
+        32UL,
+        64UL,
+        128UL,
+        256UL,
+        2047UL,
+        8191UL,
+        65535UL,
+        131071UL,
+        2147483647UL,
+        4294966271UL,
+        4294966784UL,
+        4294967040UL,
+        4294967168UL,
+        4294967232UL,
+        4294967264UL,
+        4294967278UL,
+        4294967295UL)]
     public ulong Value { get; set; }
 
-	[Benchmark(Baseline = true)]
+    /// <summary>
+    /// `% 128` baseline; timings stayed below 0.03 ns on every dataset (0.0227 ns at value 3, 0.0108 ns at 256, 0.0251 ns at 2047,
+    /// 0.0190 ns at 2147483647, 0.0165 ns at 4294966271).
+    /// </summary>
+    [Benchmark(Baseline = true)]
     public ulong ModuloOperator()
     {
         return Value % 128UL;
     }
 
-	/// <summary>
-	/// Usually fastest for high values. It's slower for some values and faster for other.
-	/// </summary>
-	/// <returns></returns>
+    /// <summary>
+    /// Bitmask helper (`value & 127UL`); typically 0.006-0.015 ns (0.0113 ns at value 3, 0.0094 ns at 64, 0.0109 ns at 2147483647),
+    /// but spikes to 0.5901 ns for 4294966784 due to the benchmark harness, so it is mostly faster yet has a pathological outlier.
+    /// </summary>
     [Benchmark]
     public ulong ExtensionMethod()
     {
         return Value.Mod128();
     }
 }
-