LLVM

[John Reimer]

On Mon, 20 Nov 2006 14:37:23 -0800, Gregor Richards <Richards at codu.org>  
wrote:


>> with  LLVM as he did for gcc.  I wish not because it would be much  
>> better if the  reference compiler development could continue on a  
>> completely open system.
>>  -JJR
>
> I have now posted this at least three times.
>
> LLVM's compiler is GCC.
>
>   - Gregor Richards

Yes, I've seen your posts. But it's unclear despite the nice little graph  
that you posted for us to consider.

Quoting the site:

"LLVM is also a collection of source code that implements the language and  
compilation strategy. The primary components of the LLVM infrastructure  
are a GCC-based C & C++ front-end, a link-time optimization framework with  
a growing set of global and interprocedural analyses and transformations,  
static back-ends for the X86, PowerPC, IA-64, Alpha and SPARC  
architectures, a back-end which emits portable C code, and a Just-In-Time  
compiler for X86 and PowerPC processors."

My question is why do they say the the LLVM infrastructure uses the  
GCC-based /C & C++ front-end/?  The backends are not GCC...  I guess this  
is just depends how far back the backend is :)?   (Oh wait... GIMPLE is a  
frontend for the virtual machine)

You mentioned GIMPLE as being used for the IR (Intermediate  
Representation) which GDC uses to interface with the GCC backend. It's  
still a little unlcear to me, so have patience.

1) Is GIMPLE a problem for use here? (License-wise)
2) If GIMPLE is the IR, this means that GDC already has all that's  
necessary to attach to LLVM?
3) Whatever the case, including a GDC front end with LLVM may be easier  
than doing so with FSF.  FSF seems to want complete ownership of the D  
frontend before they will accept it into the fold of gcc.  Not sure how  
the LLVM group will act in this matter, but there licensing method seems  
quite different.

-JJR