.Net Core 3.0
(currently in preview) adds support for hardware intrinsics.
So now we can write simd instructions in c# 🎉
Intel has a nice website for browsing through the available instructions: Intel intrinsics guide
Everything from Avx2
down seems supported. (Given that your cpu supports it ofcourse)
For double checking what c# call maps to what instruction you can check the summary of the methods: