Files
even-perfect-numbers-scanner/EvenPerfectBitScanner.Benchmarks/HeuristicMultiplyShiftBenchmarks.cs
T
2025-10-17 02:40:51 +02:00

53 lines
1.4 KiB
C#

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Jobs;
using PerfectNumbers.Core;
namespace EvenPerfectBitScanner.Benchmarks;
[SimpleJob(RuntimeMoniker.Net80, launchCount: 1, warmupCount: 1, iterationCount: 5)]
[MemoryDiagnoser]
public class HeuristicMultiplyShiftBenchmarks
{
private static readonly MultiplyShiftInput[] Inputs =
[
new(0x3FFF_FFFF_FFFF_FFFFUL, 3UL, 3, "NearOverflowShift"),
new(0x2000_0000_0000_0000UL, 7UL, 4, "HalfRange"),
new(0x1234_5678_9ABC_DEF0UL, 5UL, 5, "MixedBits"),
new(0x0000_0000_1000_0000UL, 11UL, 3, "Sparse"),
];
[ParamsSource(nameof(GetInputs))]
public MultiplyShiftInput Input { get; set; }
public static IEnumerable<MultiplyShiftInput> GetInputs()
{
return Inputs;
}
[Benchmark(Baseline = true)]
public ulong SafeMultiplyShift()
{
return ULongExtensions.MultiplyShiftRight(Input.Value, Input.Multiplier, Input.Shift);
}
[Benchmark]
public ulong ShiftFirstMultiplyShift()
{
return ULongExtensions.MultiplyShiftRightShiftFirst(Input.Value, Input.Multiplier, Input.Shift);
}
[Benchmark]
public ulong NaiveMultiplyShift()
{
return (Input.Value * Input.Multiplier) >> Input.Shift;
}
public readonly record struct MultiplyShiftInput(ulong Value, ulong Multiplier, int Shift, string Name)
{
public override string ToString()
{
return Name;
}
}
}