How to learn compilers: LLVM Edition
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How to learn compilers: LLVM Edition
1–10 of 28 posts
Re: How to learn compilers: LLVM Edition
#2More great things:
Re: How to learn compilers: LLVM Edition
#3I learned a lot about LLVM by looking at the compiler output from Clang:
clang -emit-llvm -S sample.cpp
clang -Xclang -ast-dump -fsyntax-only sample.cpp
https://godbolt.orgRe: How to learn compilers: LLVM Edition
#4since here's many compiler hackers then I'd want to ask question:
How do you distribute your frontend with LLVM?
Let's say that I have lexer, parser and emitter written in e.g Haskell (random example)
I emit LLVM IR and then I use LLVM to generate something other
but the problem is, that I need to have LLVM binaries and I'd rather avoid telling people that want to contribute to my OSS project to install LLVM because it's painful process as hell
So I thought about just adding "binaries" folder to my repo and put executables there, but the problem is that they're huge as hell! and also when you're on linux, then you don't need windows' binaries
Another problem is that LLVM installer doesnt include all LLVM components that I need (llc and wasm-ld), so I gotta compile it and tell cmake (iirc) to generate those
I thought about creating 2nd repo where there'd be all binaries compiles for all platforms: mac, linux, windows and after cloning my_repo1, then instruction would point to download specific binaries
How you people do it?
Re: How to learn compilers: LLVM Edition
#5since here's many compiler hackers then I'd want to ask question: How do you distribute your frontend with LLVM? Let's say that I have lexer, parser and emitter written in e.g Haskell (random example) I emit LLVM IR and then I use LLVM to generate something other but the problem is, that I need to have LLVM binaries and I'd rather avoid telling people that want to contribute to my OSS project to install LLVM because…
Not a compiler hacker and unfamiliar with the scene but is there a specific reason that `git-lfs` wouldn’t work? It’s the first thing that came to mind reading this. You can also pretty easily fetch specific objects as opposed to everything, so in your README you could direct contributors to only fetch specific binaries for given tasks.
Re: How to learn compilers: LLVM Edition
#6since here's many compiler hackers then I'd want to ask question: How do you distribute your frontend with LLVM? Let's say that I have lexer, parser and emitter written in e.g Haskell (random example) I emit LLVM IR and then I use LLVM to generate something other but the problem is, that I need to have LLVM binaries and I'd rather avoid telling people that want to contribute to my OSS project to install LLVM because…
You can statically link LLVM, no problem.
In fact, you never have to call any binaries specifically; just do it through code and everything should link at compile-time and become one big binary.
Re: How to learn compilers: LLVM Edition
#7since here's many compiler hackers then I'd want to ask question: How do you distribute your frontend with LLVM? Let's say that I have lexer, parser and emitter written in e.g Haskell (random example) I emit LLVM IR and then I use LLVM to generate something other but the problem is, that I need to have LLVM binaries and I'd rather avoid telling people that want to contribute to my OSS project to install LLVM because…
You can statically link LLVM, no problem. In fact, you never have to call any binaries specifically; just do it through code and everything should link at compile-time and become one big binary.
This is in fact what Zig does. Everything is statically linked into one binary that is used for compiling, linking, building, testing etc.
Re: How to learn compilers: LLVM Edition
#8I have to say personally I find general program analysis (e.g. for security) a much more interesting topic than most vanilla compiler courses. For example I recently came across this course by the maintainers of soot: https://youtube.com/playlist?list=PLamk8lFsMyPXrUIQm5naAQ08a...
Any pointers to similar courses much appreciated!
Re: How to learn compilers: LLVM Edition
#9since here's many compiler hackers then I'd want to ask question: How do you distribute your frontend with LLVM? Let's say that I have lexer, parser and emitter written in e.g Haskell (random example) I emit LLVM IR and then I use LLVM to generate something other but the problem is, that I need to have LLVM binaries and I'd rather avoid telling people that want to contribute to my OSS project to install LLVM because…
When you have an LLVM frontend, what you generally do is have your driver run the optimization and code generation steps itself using the LLVM APIs rather than using opt/llc binaries to drive this step. That way, you don't need the LLVM binaries, just the libraries that you statically link into your executable.
For example, all of the code in clang to do this is located in https://github.com/llvm/llvm-project/blob/main/clang/lib/Cod...
Re: How to learn compilers: LLVM Edition
#101. Getting Started with LLVM Core Libraries
It's a bit dated (covers DAGISel rather than GlobalISel) but it gives a thorough introduction.
2. LLVM Developer Meeting tutorials
These are really good although you'll have to put them in order yourself. They will be out of date, a little. LLVM is a moving target. Also, you don't have to go through every tutorial. For example, MLIR is not for me.
3. LLVM documentation
I spent less time reading this than going through the Developer Meeting tutorials. I generally use it as a reference.
4. Discord, LLVM email list, git blame, LLVM Weekly
... because you will have questions.
5. MyFirstTypoFix (in the docs)
... when it comes time to submit a patch.
6. Mips backend
If you're doing a backend, you will need a place to start. The LLVM documentation points you to the horribly out of date SPARC backend. Don't even touch that. AArch64 and x86 are very full featured and thus very complex (100 kloc+). Don't use those either. RISC-V is ok but concerns itself mostly with supporting new RISC-V features rather than keeping up to date with LLVM compiler services. Don't use that either although definitely work through Alex Bradbury's RISC-V backend tutorials. Read the Mips backend. It is actively maintained. It has good GlobalISel support almost on par with the flagship AArch64 and x86 backends.
BTW, Chris Lattner is a super nice guy.