Re: [avr-llvm-devel] Windows build

[John M. <ato...@gm...>]

On Fri, Dec 4, 2009 at 10:23 PM, Weddington, Eric <Eri...@at...
> wrote:

>
>
> > -----Original Message-----
> > From: John Myers [mailto:ato...@gm...]
> > Sent: Friday, December 04, 2009 10:18 PM
> > To: avr...@li...
> > Subject: [avr-llvm-devel] Windows build
> >
> >
> > I had a pain free build using Visual Studio C++ 2008 express
> > edition and CMake on Windows XP.
>
> Congratulations!
>
> > C:\_projects_\build_llvm\bin\Debug>llc.exe -O0 -filetype=asm
> > -mcpu=atmega128 reti8.ll -o -
> >         .file   "reti8.ll"
> >
> >         .text
> >         .align  16
> >         .globl  func
>
> Can we change the directive to be the full spelling?: .global
>
>
Yeah, that's an easy change (it's in AsmPrinter\AVRAsmPrinter.cpp).


> >         .type   func,@function
> > func:
> > # BB#0:
> >         ldi r24, #1
> >         mov r24, r24
>
> What's up with the redundant mov? Or will future optimization take care of
> removing this?
>
> >         ret
> >         .size   func, .-func
> >
> >
>
Good question, I haven't looked into (with any detail) how LLVM IR is
converted to native assembly.
I will probable spend some time later this weekend checking that out.