gnupic: Re: [gnupic] LLVM - was Re: [gnupic] gputils development
Subject:
Re: [gnupic] LLVM - was Re: [gnupic] gputils development
From:
"David Barnett" ####@####.####
Date:
14 Nov 2008 14:14:16 -0000
Message-Id: <4d52f78b0811140614s22859865s7b4f7a69cbdbdcc7@mail.gmail.com>
On Fri, Nov 14, 2008 at 4:04 AM, Vaclav Peroutka ####@####.#### wrote:
> >
> > That is a good idea. But IMHO Microchip has other ideas about
> > this topic. They are working on LLVM port. In fact, LLVM 2.4
> > has experimental PIC16 ports.
> > http://llvm.org/docs/ReleaseNotes.html
> >
>
> Hello Xiaofan,
>
> I had a look into LLVM docu, Getting started etc. There is "1. Read the
> documentation, 2.Read the documentation". But which documantation ? I could
> not find what is LLVM good for. And how can it help me with development for
> PIC16 architecture.
LLVM is a whole framework geared towards compiler developers, and still not
much of a product for end-users. I don't think they have much user
documentation yet, but the project looks very promising.
If you don't know all about compilers, there's usually a front-end which
translates from C, FORTRAN, Ada, C++, etc. into an intermediate
representation, and a back-end which translates the intermediate
representation into assembly or machine language for a particular arch (x86,
ARM, etc.). LLVM is a definition of the intermediate representation and a
lot of tools for dealing with it (optimizing, debugging...). With gcc the IR
is much more hidden, but LLVM standardizes the IR format and makes it easier
to enhance the whole system.
They've added a PIC16 back-end now, so you can use a front-end (like
llvm-gcc, I think) to generate the IR code, and then get PIC16 assembly or
machine code out of that, theoretically. I haven't looked much into it
myself, but that should be the gist of it.
David
