[LLVMdev] LLVM and OpenMP

[Anton Korobeynikov]

Devang,

> The easiest route would be to update llvm bitcode converter in llvm- 
> gcc-4.2 such that llvm bitcode converter operates on GCC trees after  
> OpenMP lowering phase is executed.
> 
> If you're interested, we welcome contribution on OpenMP front.
I already slightly looked on OpenMP in llvm-gcc 4.2.

Internally OpenMP lowering in gcc is split into two phases. Funny, but
llvm converter is run between these phases :) It looks like second phase
uses some gcc analysis passes (like dominance info, etc). 

In order to support OpenMP in llvm-gcc 4.2 we should:
1. Decide at which level we should handle openmp trees in llvm-gcc
2. Define a set of openmp builtins, which will need to be supported in
llc codegen
3. Something I'm not aware of :)

If anyone want to work on bringing openmp to llvm-gcc, I'll be happy to
help.

-- 
With best regards, Anton Korobeynikov.

Faculty of Mathematics & Mechanics, Saint Petersburg State University.