Re: Add -m{arch,tune}=local for x86/x86-64

[Michael Matz <matz at suse dot de>]

Hi,

On Tue, 14 Mar 2006, Andrew Pinski wrote:

> On Mar 14, 2006, at 8:51 PM, Michael Matz wrote:
> 
> > The patch is currently in testing.  And comments?  Okay for trunk?
> 
> How does this handle crosses from the looks of it, it will cause a link
> failure when crossing from a non x86 target.

I convinced myself somehow that gcc.c will not include the target but the
host header, which would avoid this problem.  On reflection that's not
true.  Hmm.  Any advice?  I could simply #ifdef CROSS_COMPILE the define 
and the function definition.

> Also it will cause
> driver-i386.c to be compiled for crosses from x86 to anything else.

Yes, though that's not a problem (when I was still convinced of the above 
wrong thing, I argued that a user who would use -march=local on a i386 
machine in a cross compiler would get what he deserves, as giving this 
flag doesn't make sense in a cross environment).  I could have excluded 
the file for cross compiles, but the other files mentioned in config.host 
are also not special cased, so it's at least consistent.  I realize that 
those other files (e.g. host-linux.o) actually have a use also in a cross 
compiler, unlike my new function.  But suppose someone would go add a new 
hook (e.g. cache size thingies to optimize bitmap functions or the like), 
and implement it for only i386.  The natural place now would be 
driver-i386.c (or a file included in cc1), and then it actually should be 
included also in cross compilers.  I think the above mentioned #ifdefing 
around the function might be better.


Ciao,
Michael.