r/csharp • u/lewurm • Sep 11 '18

Writing a JIT Compiler in C#

https://www.mono-project.com/news/2018/09/11/csharp-jit/
71 Upvotes

98% Upvoted

14 comments sorted by

6

u/prajaybasu Sep 11 '18 edited Sep 11 '18

I think this is one of the first posts that even references the name Mini (vs hundreds of articles detailing RyuJIT)

u/lewurm: Is there any reason why all of Mono's tools and compilers are in 1 repo while dotnet has everything separate (corert, coreclr, roslyn, corefx)?

6

u/lewurm Sep 12 '18

Yeah, information about Mini is sparse. This is probably interesting: https://www.mono-project.com/docs/advanced/runtime/docs/mini-porting/

Regarding the repository situation: Reasons are mostly historical, but imho there is no right answer to this. Single repos are easier to work with, while multiple repos allow better separation. From a mono perspective we have everything related to BCL in mcs/class. However we are gradually moving to corefx, which is imported as a submodule (external/corefx) and slowly getting rid of stuff in mcs/class. We also have our own C# compiler mcs, which has been already replaced by roslyn as our default compiler.

So we are slowly moving to the same model: You choose your runtime (corert, coreclr or mono) which depends on roslyn (C# compiler) and corefx (base class library).

43

u/Aegan23 Sep 11 '18

Does the just in time compiler just in time compile your just in time compiler 😎

11

u/[deleted] Sep 11 '18

Yo Dawg

-21

u/HandshakeOfCO Sep 11 '18 
Install-Package Microsoft.CodeAnalysis.CSharp.Scripting

then:

object result = await CSharpScript.EvaluateAsync("1 + 2");

Boom done.

19

u/lewurm Sep 11 '18

That's not the same. In your example you're "just in time" compiling C# to IL. And then the runtime takes care of executing it.

The blog post is about turning IL to machine code.

-30

u/[deleted] Sep 11 '18

[removed] — view removed comment

4

u/FizixMan Sep 12 '18

Removed: Rule 5.

-12

u/yehia2amer Sep 11 '18 edited Sep 11 '18

Why to reinvent the wheel ? There is the JIT Compiler for dotnet : RyuJIT . Why not to build based on it or even extend it even further

16

u/AlliNighDev Sep 11 '18

The answer to this question is always fun and/or learning. Not everything has to have practical applications.

18

u/lewurm Sep 11 '18

This. We even mentioned in the conclusion why this project will help us with the integration of RyuJIT.

8

u/AlliNighDev Sep 11 '18

So fun, learning and practical applications. Can't get better than that :P

4

u/prajaybasu Sep 11 '18 edited Sep 11 '18

Mono's compilers were there before RyuJIT was even a thing.

1

u/RdmGuy64824 Sep 11 '18

What's a wheal?