This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: GCC for SPARC Systems


On Fri, 2006-03-10 at 14:06 -0800, Alexey Starovoytov wrote:
> On Fri, 10 Mar 2006, Andrew Pinski wrote:
> 
> >
> > On Mar 10, 2006, at 3:34 PM, Alexey Starovoytov wrote:
> >
> > > Few major infrastructure features needs to be done first.
> >
> > Like?  Please give examples.  If link time optimizations,
> > that is already starting to be worked on.
> 
> I doesn't look that my opinion here worth even 1 cent,
> but here are few things:
> 
>  - inter-proc (link time) opt
>    I think LLVM is a better approach.

So is Sun moving to it?
We are considering it (GCC being "we")

> 
>  - 2nd link time opt
>    not re-optimization like above, but asm code optimizations.
>    Looks like LLVM is targeting that as well. 

Not as far as i know, actually.

> Check -xlinkopt flag and BIT
>  - struct type aliasing
>    Great progress in 4.1, but still much behind Sun. Check -xalias_level flag

Actually, we aren't.  I've looked at what Sun does, and the tree level
does better in 4.2 than what you do in terms of struct aliasing. The RTL
level doesn't.

> 
>  - auto parallelization
>    doesn't look anything is being done here. Check -xautopar

This isn't a useful optimization for more than 10% of users, which is
why it's not done yet.


> All of the above is done by sun compiler and gcc4ss (except openmp).
> A lot of other things are coming.
> 
> Also I don't want to start "tree vs orc" flame, but it seems that Sun's IR
> is better suited for the above opts. Ok. Ok. It's not.

The reality is, you can either sit on the sidelines and pretend that GCC
isn't going to each your lunch on every other platform in 5-10 years, or
you can help make it work well on your platform.

Sitting on the sidelines and saying "Look, you don't have this", instead
of implementing *that thing* is a bit silly.



Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]