RE: [avr-chat] Can't Install avr-gcc in FreeBSD

[Eric Weddington]

> -----Original Message-----
> From: address@hidden
> [mailto:address@hidden
>  On Behalf Of Joerg Wunsch
> Sent: Wednesday, August 22, 2007 1:28 PM
> To: address@hidden
> Subject: Re: [avr-chat] Can't Install avr-gcc in FreeBSD
>
> David Brown <address@hidden> wrote:
>
> > Back to gcc and other compilers - there is one area where
> gcc lags many
> > of the big names in commercial compilation.  ...
> > ..., but what is
> > lacking is proper link time optimisation.
>
> My guess is this is mainly lack of experience with those features by
> the GCC developers, rather than lack of the tools.  For example, Björn
> Haase recently implemented linker relaxations for the AVR, which is
> something I've already noticed (supposedly, in IAR generated code)
> when disassembling the first JTAG ICE firmware years ago.  Still,
> until very recently, there wasn't even the respective -mrelax option
> available for AVR-GCC, you had to make your way through -Wl,-relax in
> order to use it.  Anatoly recently changed that, as I understand.

FYI, GCC does have an "LTO" project (Link Time Optimizations) that I guess
several people are working on. It has it's own branch in the GCC repository.
There was a talk about some of the LTO stuff at the most recent GCC Summit.
There are some pages on it in the GCC wiki. Start here:
<http://gcc.gnu.org/wiki/LinkTimeOptimization>

So the GCC folks *are* working on it. Stuff like this takes time as, by
nature, these folks are very conservative when making changes. They don't
want to break things in the middle when they're adding things.

Offhand, I don't know the schedule for inclusion of this. I tend to doubt
that it will get included in 4.3. My gut feel is it might be in 4.4. But I
could be horribly wrong.

Eric