Clarify LLVM IR/CIL differences

Author: Kobzol

posts/2024-11-01-gsoc-2024-results.md

@@ -130,7 +130,7 @@ TODO
 
 As was already mentioned above, the Rust compiler can be used with various codegen backends. One of these is the [.NET backend][codegen-clr], which compiles Rust code to the Common Intermediate Language (CIL), which can then be executed by the .NET Common Language Runtime (CRL). This backend allows interoperability of Rust and .NET (e.g. C#) code, in an effort to bring these two ecosystems closer together.
 
-At the start of this year, the .NET backend was already able to compile complex Rust programs, but it was still lacking certain crucial features. The goal of this GSoC project, implemented by Michał (aka Fractal Fir), who is in fact the sole author of the backend, was to extend the functionality of this backend in various areas. As a target goal, he set out to extend the backend so that it could be used to run tests using the `cargo test` command. Even though it might sound trivial, properly compiling and running the Rust test harness is non-trivial, as it makes use of complex features such as dynamic trait objects, atomics, panics, unwinding or multithreading. These features were tricky to implement in this codegen backend, especially because of large differences between how the .NET runtime works and the way LLVM usually does things.
+At the start of this year, the .NET backend was already able to compile complex Rust programs, but it was still lacking certain crucial features. The goal of this GSoC project, implemented by Michał (aka Fractal Fir), who is in fact the sole author of the backend, was to extend the functionality of this backend in various areas. As a target goal, he set out to extend the backend so that it could be used to run tests using the `cargo test` command. Even though it might sound trivial, properly compiling and running the Rust test harness is non-trivial, as it makes use of complex features such as dynamic trait objects, atomics, panics, unwinding or multithreading. These features were especially tricky to implement in this codegen backend, because the LLVM intermediate representation (IR) and CIL have fundamental differences, and not all LLVM intrinsics have .NET equivalents.
 
 However, this did not stop Michał. He has been working on this project tirelessly, implementing new features, fixing various issues and learning more about the compiler's internals every new day. He has also been documenting his journey with (almost) daily [updates on Zulip](https://rust-lang.zulipchat.com/#narrow/channel/421156-gsoc/topic/Project.3A.20Rust.20to.20.2ENET.20compiler), which were fascinating to read. Once he has reached his original goal, he moved the goalpost up to another level and attempted to run the compiler's own test suite using the .NET backend. This helped him uncover additional edge cases and also led to a refactoring of the whole backend that resulted in significant performance improvements.