[LLVMdev] LLVM inquiry

[Duncan Sands]

Hi,

> 1) What is the status of fortran/llvm-gfortran in the context of LLVM?
> Are there any plans to support fortran?

gfortran works pretty well.  You'll have to build it from the llvm-gcc
source yourself though (you need to add fortran to the --enable-languages
list).  There are some known bugs, which are most of the llvm bugs with
numbers from 2441 to 2450.  I don't know if it builds on the mac.

> 2)  Are you planning to use the GCC-based front-end in the long-term
> or is that just temporary?

No one has volunteered to write a clang-like front-end for Fortran yet,
so it's just llvm-gfortran for the moment.

> 3) Are there any performance numbers available comparing with standard
> GCC?

Yes, see http://lists.cs.uiuc.edu/pipermail/llvmdev/2008-June/015441.html
The conclusion is that llvm-gfortran is on the whole a bit slower than
mainline.
There are some Fortran programs in the llvm testsuite but currently they
are compiled using g2c followed by llvm-gcc (C front-end) IIRC, rather
than using llvm-gfortran.  It would be great if someone could tweak the
testsuite to use llvm-gfortran if it is available.

I hope this helps.

Best wishes,

Duncan.