Re: GCC 3.5 Status (2004-08-29)

[Jan Hubicka <hubicka at ucw dot cz>]

> On Monday 30 August 2004 12:04, Giovanni Bajo wrote:
> > Thanks for the update. Do you think it is feasable to have a special
> > version of DCE/CCP (or a special flag in them) so that they don't destroy
> > user variables, to be used at -O0?
> 
> We discussed that, yes.  You could look into how CCP propagates
> things like addresses and so on, and figure out other things that
> cause us to lose the user's variable.
> DCE is not a real problem.  If CCP would just not turn so many
> statements into dead code, it would work ;-)

I think all we need is to avoid CCP on user variables so user can change
their value and DCE killing whole statements so user can breakpoint.
Perhaps we can even consider idea of passing down the NOPs for
statements that have completely no effect.  This should be embeddable
into existing CCP/DCE code... perhaps ;)

Honza
> 
> Gr.
> Steven
>