Re: RFC: New approach to --with-cpu

[Daniel Jacobowitz <drow@mvista.com>]

On Wed, Jul 31, 2002 at 04:17:10PM +0100, Richard Earnshaw wrote:
> > On Wed, Jul 31, 2002 at 10:46:50AM -0400, John David Anglin wrote:
> > > > Well, that's no problem.  A first cut of this patch offered defaults
> > > > for -march= and -mtune= separately on MIPS.  I could do the same for
> > > > PA easily.
> > > 
> > > I would be happy if the configure option for setting the default
> > > scheduling was "--with-schedule" rather than "--with-cpu".  This
> > > will set the default for -mschedule=.  Similarly, when an option
> > > is introduced to set the default arch, then I would like to use
> > > "--with-arch".
> > > 
> > > Using the same suffix in the configure and gcc options makes the
> > > relationship between the two options clearer.
> > 
> > I was actually debating this.  The advantage of using --with-cpu for
> > all targets is consistency across architectures.  The advantage of
> > saying --with-schedule, --with-arch, --with-tune is flexibility.  I
> > lean towards consistency, but I could be persuaded either way - does
> > anyone else have an opinion?
> > 
> > I suppose using --with-schedule on PA would also mean we could have
> > --with-arch, which is nice.
> > 
> 
> In what way is --with-schedule different from --with-tune?  Are they 
> synonyms?
> 
> I can understand the split --with-arch --with-tune and --with-cpu (with 
> the latter meaning -with-arch=<arch-of-cpu> --with-tune=cpu), but I'm not 
> sure of the distinction between schedule and tune.

Historical inconsistency.  PA appears to define -mschedule but not
-mtune; the meaning appears to be about the same.  One thing I will
_not_ do is allow --with-tune to set -mschedule, though; I'd rather add
-mtune to PA and then use --with-tune.

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer