87 lines
2.2 KiB
C#
87 lines
2.2 KiB
C#
using System.Runtime.CompilerServices;
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using BenchmarkDotNet.Attributes;
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using BenchmarkDotNet.Jobs;
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using PerfectNumbers.Core;
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namespace EvenPerfectBitScanner.Benchmarks;
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[SimpleJob(RuntimeMoniker.Net80, launchCount: 1, warmupCount: 1, iterationCount: 3)]
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[MemoryDiagnoser]
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public class Mod6ComparisonBenchmarks
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{
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private static readonly byte[] Mod6Lookup = [0, 3, 4, 1, 2, 5];
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[MethodImpl(MethodImplOptions.AggressiveInlining)]
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public static ulong Mod6(ulong value) => Mod6Lookup[(int)(((value % 3UL) << 1) | (value & 1UL))];
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private const int Iterations = 10_000_000;
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private const ulong Divisor = 6UL;
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private static readonly ulong FastDivMul = (ulong)(((UInt128)1 << 64) / Divisor);
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[Params(3UL, 131071UL, ulong.MaxValue - 1024UL)]
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public ulong StartValue { get; set; }
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[Benchmark(Baseline = true, OperationsPerInvoke = Iterations)]
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public ulong ModuloOperator()
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{
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ulong checksum = 0UL;
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ulong value = StartValue;
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for (int i = 0; i < Iterations; i++)
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{
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checksum += value % Divisor;
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value += (ulong)((i & 15) + 1);
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}
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return checksum;
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}
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[Benchmark(OperationsPerInvoke = Iterations)]
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public ulong DivisionBased()
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{
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ulong checksum = 0UL;
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ulong value = StartValue;
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for (int i = 0; i < Iterations; i++)
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{
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ulong quotient = value / Divisor;
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checksum += value - quotient * Divisor;
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value += (ulong)((i & 15) + 1);
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}
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return checksum;
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}
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[Benchmark(OperationsPerInvoke = Iterations)]
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public ulong FastDivHigh()
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{
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ulong checksum = 0UL;
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ulong value = StartValue;
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for (int i = 0; i < Iterations; i++)
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{
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ulong quotient = value.FastDiv64(Divisor, FastDivMul);
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checksum += value - quotient * Divisor;
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value += (ulong)((i & 15) + 1);
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}
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return checksum;
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}
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[Benchmark(OperationsPerInvoke = Iterations)]
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public ulong ExtensionMethod()
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{
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ulong checksum = 0UL;
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ulong value = StartValue;
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for (int i = 0; i < Iterations; i++)
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{
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checksum += Mod6(value);
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value += (ulong)((i & 15) + 1);
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}
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return checksum;
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}
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}
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