Benchmark results and TODOs added / updated

EvenPerfectBitScanner.Benchmarks/Mod5ULongBenchmarks.cs

@@ -9,31 +9,33 @@ namespace EvenPerfectBitScanner.Benchmarks;
 [MemoryDiagnoser]
 public class Mod5ULongBenchmarks
 {
-	[MethodImpl(MethodImplOptions.AggressiveInlining)]
-	public static ulong Mod5(ulong value) =>
-			(
-				(uint)(value & ULongExtensions.WordBitMask) +
-				(uint)((value >> 16) & ULongExtensions.WordBitMask) +
-				(uint)((value >> 32) & ULongExtensions.WordBitMask) +
-				(uint)((value >> 48) & ULongExtensions.WordBitMask)
-			) % 5;
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ulong Mod5(ulong value) =>
+        ((uint)(value & ULongExtensions.WordBitMask)
+         + (uint)((value >> 16) & ULongExtensions.WordBitMask)
+         + (uint)((value >> 32) & ULongExtensions.WordBitMask)
+         + (uint)((value >> 48) & ULongExtensions.WordBitMask)) % 5UL;
 
     [Params(5UL, 8191UL, 131071UL, 2147483647UL, ulong.MaxValue - 31UL)]
     public ulong Value { get; set; }
 
-	/// <summary>
-	/// Fastest
-	/// </summary>
-	[Benchmark(Baseline = true)]
+    /// <summary>
+    /// `% 5` baseline; measured 0.2657 ns at value 5, 0.2622 ns at 8191, 0.2640 ns at 131071, 0.2645 ns at 2147483647, and 0.2696 ns
+    /// near ulong.Max.
+    /// </summary>
+    [Benchmark(Baseline = true)]
     public ulong ModuloOperator()
     {
         return Value % 5UL;
     }
 
+    /// <summary>
+    /// Extension helper; slower at 0.431-0.448 ns (0.4305 ns at value 5, 0.4404 ns at 8191, 0.4359 ns at 131071, 0.4361 ns at
+    /// 2147483647, 0.4481 ns near ulong.Max), roughly 1.6-1.7x the `%` cost.
+    /// </summary>
     [Benchmark]
     public ulong ExtensionMethod()
     {
         return Mod5(Value);
     }
 }
-