The new cross-platform .NET Core framework and runtime has major performance upgrades in the last few years and the newest v3.0 release [1] in a few weeks will have even more including hardware intrinsics [2]. There are several optimizations I can see in the C# source to make this implementation even faster.

1. https://devblogs.microsoft.com/dotnet/performance-improvemen...

2. https://devblogs.microsoft.com/dotnet/hardware-intrinsics-in...