BigInteger go brrr in .NET 9

BigIntegerBenchmarks.cs

using System.Numerics;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Diagnosers;
using BenchmarkDotNet.Jobs;

namespace DotNetBenchmarks;

[MemoryDiagnoser]
[SimpleJob(RuntimeMoniker.Net80, baseline: true)]
[SimpleJob(RuntimeMoniker.Net90)]
public class BigIntegerBenchmarks
{
    [Benchmark]
    public long ProjectEuler97()
    {
        BigInteger value = (28433 * BigInteger.Pow(2, 7830457)) + 1;

        var digits = new List<int>(10);

        for (int i = 0; i < 10; i++)
        {
            value = BigInteger.DivRem(value, 10, out var rem);
            digits.Add((int)rem);
        }

        digits.Reverse();

        return FromDigits(digits);
    }

    private static long FromDigits(List<int> collection)
    {
        double result = 0;

        for (int j = 0; j < collection.Count - 1; j++)
        {
            result += collection[j] * Math.Pow(10, collection.Count - j - 1);
        }

        result += collection[collection.Count - 1];

        return (long)result;
    }
}

results.md

BenchmarkDotNet v0.14.0, Windows 11 (10.0.22621.4037/22H2/2022Update/SunValley2)
12th Gen Intel Core i7-1270P, 1 CPU, 16 logical and 12 physical cores
.NET SDK 9.0.100-preview.7.24407.12
  [Host]   : .NET 9.0.0 (9.0.24.40507), X64 RyuJIT AVX2
  .NET 8.0 : .NET 8.0.8 (8.0.824.36612), X64 RyuJIT AVX2
  .NET 9.0 : .NET 9.0.0 (9.0.24.40507), X64 RyuJIT AVX2

Method	Job	Runtime	Mean	Error	StdDev	Ratio	RatioSD	Allocated	Alloc Ratio
ProjectEuler97	.NET 8.0	.NET 8.0	4,695.3 ms	138.27 ms	405.53 ms	1.01	0.12	12.14 MB	1.00
ProjectEuler97	.NET 9.0	.NET 9.0	967.4 ms	19.07 ms	20.40 ms	0.21	0.02	12.14 MB	1.00

.NET 8 Speedscope

.NET 9 Speedscope