On: ErLLVM: LLVM backend for high performance Erlang

[delinka]

I think I need some guidance in understanding this project. The typical LLVM-base compiler 'stack' looks like this:

  [Front-end] -> [LLVM AST] -> [Back-end]

Where the front end compiles your language of choice to LLVM's AST format, and a back-end translates AST to machine code. All the really awesome code optimization stuff happens at the AST level before the back-end gets involved.

So is ErLLVM a back-end that emits Erlang (such that any front-end language can be translated to Erlang)? Or is it an LLVM front-end that compiles Erlang to LLVM AST? An in the latter case, if LLVM already targets ARM, why does ErLLVM need to do work related to ARM?

[masklinn → delinka]

> Or is it an LLVM front-end that compiles Erlang to LLVM AST?

This, kind-of. It's a new HiPE[0] backend. See [1] for how LLVM integrates into the existing Erlang pipeline.

[0] http://www.it.uu.se/research/group/hipe/

[1] http://erllvm.softlab.ntua.gr/documentation/design/pipeline/

[signa11 → delinka]

if you have not seen this: http://www.erlang-factory.com/upload/presentations/519/erllv... already, it might serve as a high-level overview of what is being attempted here ?