68 lines
2.4 KiB
C#
68 lines
2.4 KiB
C#
using System.Collections.Generic;
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using System.Numerics;
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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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[ShortRunJob(RuntimeMoniker.Net80)]
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[MemoryDiagnoser]
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public class MutableUInt128MultiplyAddBenchmarks
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{
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private static readonly MultiplyAddInput[] Inputs =
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[
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new(Create(0UL, 0x0000_0000_0000_0007UL), 0x3UL, 0x5UL, "TinyOperands"),
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new(Create(0x1234_5678_9ABC_DEF0UL, 0x0FED_CBA9_8765_4321UL), 0xFFFF_FFFF_0000_0001UL, 0x1357_9BDF_2468_ACEEUL, "MixedOperands"),
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new(Create(0xFFFF_FFFF_FFFF_FFFFUL, 0xFFFF_FFFF_FFFF_FFFFUL), 0xFFFF_FFFF_FFFF_FFFBUL, 0xFFFF_FFFF_FFFF_FFF7UL, "NearMaxOperands"),
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];
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[ParamsSource(nameof(GetInputs))]
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public MultiplyAddInput Input { get; set; }
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public static IEnumerable<MultiplyAddInput> GetInputs() => Inputs;
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private static UInt128 Create(ulong high, ulong low)
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{
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return ((UInt128)high << 64) | low;
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}
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/// <summary>
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/// Baseline MultiplyAdd implementation that chains Multiply and Add; measured 4.59 ns with mixed operands,
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/// 4.68 ns when both limbs and inputs are near their maxima, and 4.49 ns with tiny operands.
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/// </summary>
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/// <remarks>
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/// Observed means: MixedOperands 4.593 ns, NearMaxOperands 4.681 ns, TinyOperands 4.487 ns.
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/// </remarks>
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[Benchmark(Baseline = true)]
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public UInt128 MultiplyAddChained()
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{
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MutableUInt128 value = new(Input.InitialValue);
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value.MultiplyAdd(Input.Multiplier, Input.Addend);
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return value.ToUInt128();
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}
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/// <summary>
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/// Fully inlined MultiplyAdd implementation that kept all arithmetic inside the method; landed at 4.11 ns on mixed operands,
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/// 4.25 ns on near-max inputs, and 4.27 ns on tiny operands.
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/// </summary>
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/// <remarks>
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/// Observed means: MixedOperands 4.109 ns, NearMaxOperands 4.253 ns, TinyOperands 4.271 ns.
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/// </remarks>
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[Benchmark]
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public UInt128 MultiplyAddFullyInlined()
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{
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MutableUInt128 value = new(Input.InitialValue);
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value.MultiplyAddInline(Input.Multiplier, Input.Addend);
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return value.ToUInt128();
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}
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public readonly record struct MultiplyAddInput(UInt128 InitialValue, ulong Multiplier, ulong Addend, string Name)
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{
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public override string ToString()
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{
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return Name;
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}
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}
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}
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