Extension methods benchmarked. Slower alternatives replaced.

EvenPerfectBitScanner.Benchmarks/Mod11_7_5_3Benchmarks.cs

@@ -1,32 +1,92 @@
+using System.Runtime.CompilerServices;
 using BenchmarkDotNet.Attributes;
-using PerfectNumbers.Core;
 
 namespace EvenPerfectBitScanner.Benchmarks;
 
 [MemoryDiagnoser]
 public class Mod11_7_5_3Benchmarks
 {
+	private static readonly byte[] Mod7ByteCoefficients = [1, 4, 2, 1, 4, 2, 1, 4];
+	private static readonly byte[] Mod11ByteCoefficients = [1, 3, 9, 5, 4, 1, 3, 9];
+
+	[MethodImpl(MethodImplOptions.AggressiveInlining)]
+	private static ulong ReduceMod7(uint value)
+	{
+		while (value >= 7U)
+		{
+			value = (value >> 3) + (value & 7U);
+			if (value >= 7U && value < 14U)
+			{
+				value -= 7U;
+			}
+		}
+
+		return value;
+	}
+
+	[MethodImpl(MethodImplOptions.AggressiveInlining)]
+	private static ulong ReduceMod11(uint value)
+	{
+		while (value >= 11U)
+		{
+			value = (value & 15U) + ((value >> 4) * 5U);
+			if (value >= 11U && value < 22U)
+			{
+				value -= 11U;
+			}
+		}
+
+		return value;
+	}
+
+	[MethodImpl(MethodImplOptions.AggressiveInlining)]
+	private static void Mod11_7_5_3(ulong value, out ulong mod11, out ulong mod7, out ulong mod5, out ulong mod3)
+	{
+		uint mod3And5Accumulator = 0U;
+		uint mod7Accumulator = 0U;
+		uint mod11Accumulator = 0U;
+
+		int index = 0;
+		byte current;
+		ulong temp = value;
+
+		byte[] mod7ByteCoefficients = Mod7ByteCoefficients;
+		byte[] mod11ByteCoefficients = Mod11ByteCoefficients;
+		do
+		{
+			current = (byte)temp;
+			mod3And5Accumulator += current;
+			mod7Accumulator += (uint)(current * mod7ByteCoefficients[index]);
+			mod11Accumulator += (uint)(current * mod11ByteCoefficients[index]);
+
+			temp >>= 8;
+			index++;
+		}
+		while (temp != 0UL);
+
+		mod3 = mod3And5Accumulator % 3;
+		mod5 = mod3And5Accumulator % 5;
+		mod7 = (uint)ReduceMod7(mod7Accumulator);
+		mod11 = (uint)ReduceMod11(mod11Accumulator);
+	}
+
     [Params(3UL, 8191UL, 131071UL, 2147483647UL)]
     public ulong Value { get; set; }
 
-    [Benchmark(Baseline = true)]
+	/// <summary>
+	/// Fastest
+	/// </summary>
+	[Benchmark(Baseline = true)]
     public (ulong Mod11, ulong Mod7, ulong Mod5, ulong Mod3) ModuloOperator()
     {
         ulong value = Value;
         return (value % 11UL, value % 7UL, value % 5UL, value % 3UL);
     }
 
-    [Benchmark]
-    public (ulong Mod11, ulong Mod7, ulong Mod5, ulong Mod3) ExtensionMethods()
-    {
-        ulong value = Value;
-        return (value.Mod11(), value.Mod7(), value.Mod5(), value.Mod3());
-    }
-
     [Benchmark]
     public (ulong Mod11, ulong Mod7, ulong Mod5, ulong Mod3) CombinedMethod()
     {
-        Value.Mod11_7_5_3(out ulong mod11, out ulong mod7, out ulong mod5, out ulong mod3);
+        Mod11_7_5_3(Value, out ulong mod11, out ulong mod7, out ulong mod5, out ulong mod3);
         return (mod11, mod7, mod5, mod3);
     }
 }