Re: calculate_global_regs_live

[Jan Hubicka <jh at suse dot cz>]

> > It is kind of feature to limit work needed to update liveness, but it is
> > broken as it ineed don't have to converge.  In the past we always
> > somehow papered around.
> 
> It indeed appears to be a long-standing problem, that I rediscovered again.  
> If we can't find a definitive solution, I'll add large comments in the code 
> so that the next guy doesn't have to go through the same discovery process.
> 
> Thanks for the quick response.
> 
> > There is patch by Zdenek to ensure finitarity of the propagation that I
> > think is best compromise sollution for this problem unless we want to go
> > for DJ-graphs based liveness computation that is much more involved and
> > can't embedde dead code removal as we do right now.
> > http://gcc.gnu.org/ml/gcc-patches/2003-01/msg02059.html
> 
> What happened to this patch, Zdenek?  Was it even reviewed?

I remember some at least partial review done by Zack, but it apparently
never was rejected or accepted.  Zdenek will know more.

Honza
> 
> -- 
> Eric Botcazou