Re: [avr-gcc-list] Unused registers saves/restores ?

[E. Weddington]

> 
> > >From the GCC 3.3 manual:
> >
> > ------
> > -fssa
> >      Perform optimizations in static single assignment
> > form. Each function's flow graph is translated into SSA
> > form, optimizations are performed, and the flow graph is
> > translated back from SSA form. Users should not specify
> > this option, since it is not yet ready for production 
use.
> > ------
> 
> *sigh* You would have thought that an analytical tool as 
old as SSA would
> have made it into GCC by now?  Oh well, back to 
research ;-)
> 

If you get on the GCC list, you'll find out that they're in 
the middle of an "overhaul" I guess you'd call it. Various 
people are working on adding new data structures that will 
significantly help in bringing in various optimizations. 
Some of this stuff I see it looks like might be included in 
the 3.4 branch.

You have to remember they're dealing with many front-ends 
(languages) and many, many more back-ends (targets) and 
they have to do all these changes in incremental steps so 
nothing breaks along the way.

Maybe you'd be interested in helping out?

Eric