| Yeah. A few highlights, as can be seen in some of the blog posts mentioned by other replies: - 'Span<T>' to represent chunks of either managed OR unmanaged memory without using unsafe pointers throughout [0][1] - Not relevant to this task necessarily, but a lot of machinery has been added to allow reuse of objects for tasks like queuing thread pool work, or waiting for an asynchronous result. - Lots of intrinsics helpers for SIMD workloads, and increased usage of such intrinsics in internal parsers/etc. - Generally improving a lot of the internal IO to take advantage of other improvements in the runtime. - PGO (Performance Guided Optimization) on the JIT side, essentially helps with things like better devirt [2] and other improvements. - AOT compilation, if that's your thing, (I do believe the fastest C# 1BRC submissions use this) [0] - To be clear, unsafe can still be faster, however for most cases Span is fine and gives you a little more runtime safety. [1] - You can also grab a Span<T> of a primitive (i.e. int, char) within a method, so long as you don't blow up stack, this is very nice when you need a small buffer for parsing but don't want to thrash the GC or deal with volatile or locks on some sort of pool. [2] - Devirt historically was a problem in 'call heavy' .NET apps when Interfaces are used, before PGO there was more than one library I worked on where we intentionally used abstract base classes rather than interfaces due to the need to squeeze as much out as we could. |