Re: PATCH: Add --with-arch=cpu (Re: Should gcc configurted for CPU to generate code for CPU by default?)

["H. J. Lu" <hjl at lucon dot org>]

On Fri, Jul 19, 2002 at 02:03:29PM -0400, Daniel Jacobowitz wrote:
> On Fri, Jul 19, 2002 at 10:55:47AM -0700, H. J. Lu wrote:
> > On Fri, Jul 19, 2002 at 01:49:52PM -0400, Daniel Jacobowitz wrote:
> > > > > 
> > > > > Can't this be done at the driver level?  We have different handling of
> > > > > 
> > > > 
> > > > What do you mean by that?
> > > 
> > > I.E. make the GCC driver supply a default value of -mcpu if none is
> > > specified on the command line, the same way sane programs set defaults.
> > > 
> > 
> > That is exactly what the gcc driver is doing today. My patch provides
> > a way to choose a different default value for -march at the configure
> > time. Without my change, the default value for -march is i386 for all
> > ia32 processors and it is fixed.
> 
> No, that's not what the driver does today.  I mean that if the driver
> was built with --with-arch=, and the driver does not see an -march=,
> then the driver should supply one.  Then we won't need any changes to
> backends.

I am really confused here. To me, my patch does exactly what you said
above. Wait, did you mean gcc.c should handle -march=, not i386.c?
I have an impresssion that most, if not all, "-mxxx" switches are 
handled in the backend. I don't see why my patch should change that.

FWIW, "-mxxx" switches are backend dependent by definition. Did I miss
something here?


H.J.