On Tue, 2011-07-26 at 17:03 -0500, Kumar Gala wrote: > On Jul 26, 2011, at 11:18 AM, Richard Purdie wrote: > > > On Tue, 2011-07-26 at 10:22 -0500, Kumar Gala wrote: > >> On Jul 26, 2011, at 8:59 AM, Richard Purdie wrote: > >> > >>> On Tue, 2011-07-26 at 08:47 -0500, Kumar Gala wrote: > >>>> On Jul 26, 2011, at 7:44 AM, Richard Purdie wrote: > >>>> > >>>>> Signed-off-by: Richard Purdie <[email protected]> > >>>>> --- > >>>>> meta/conf/machine/include/powerpc/arch-powerpc.inc | 45 > >>>>> +++++++++++++++++++- > >>>>> meta/conf/machine/include/tune-ppc603e.inc | 12 ++++- > >>>>> meta/conf/machine/include/tune-ppce300c2.inc | 12 ++++- > >>>>> meta/conf/machine/include/tune-ppce500.inc | 13 ++++-- > >>>>> meta/conf/machine/include/tune-ppce500mc.inc | 12 ++++- > >>>>> meta/conf/machine/include/tune-ppce500v2.inc | 12 ++++- > >>>>> 6 files changed, 88 insertions(+), 18 deletions(-) > >>>> > >>>> One thing I'm wondering about as we do this is the ability to pass > >>>> --with-cpu to gcc & [e]glibc configure to pickup proper optimized cfgs > >>>> & libs for a given target. > >>> > >>> As far as I can tell, gcc 4.x has no --with-cpu option. We pass the > >>> correct march and mtune options to the compiler at runtime through > >>> CFLAGS and friends. > >> > >> Hmm, gcc still supports this: > >> > >> http://gcc.gnu.org/install/configure.html > >> > >> --with-cpu=cpu > >> --with-cpu-32=cpu > >> --with-cpu-64=cpu > >> Specify which cpu variant the compiler should generate code for by > >> default. cpu will be used as the default value of the -mcpu= switch. This > >> option is only supported on some targets, including ARM, i386, M68k, > >> PowerPC, and SPARC. The --with-cpu-32 and --with-cpu-64 options specify > >> separate default CPUs for 32-bit and 64-bit modes; these options are only > >> supported for i386, x86-64 and PowerPC. > >> > >> http://gcc.gnu.org/install/specific.html > >> > >> powerpc-*-* > >> You can specify a default version for the -mcpu=cpu_type switch by using > >> the configure option --with-cpu-cpu_type. > > > > I couldn't find that looking at the configure script :/. > > > > Anyhow, according to that page, its to "Specify which cpu variant the > > compiler should generate code for by default. cpu will be used as the > > default value of the -mcpu= switch". Since we always specify -mcpu when > > needed, I don't believe this is an issue for us as far as the build > > system goes. > > > > If you're talking about the gcc we build for the target, we should > > really encode all the cpu/tune options in there, not just part of the > > config so again, I don't think its appropriate to the way we use gcc. > > What about tool chains produced as part of a ADT, wouldn't it be useful for > such as case? > > Seems like having ability to pass '--with-cpu' ends up being useful to set > default for things like 32 vs 64-bit on multiple.
ADT passes an environment script with all the appropriate flags contained within including tunings which --with-cpu doesn't help with so I'm not sure its so useful there. Cheers, Richard _______________________________________________ Openembedded-core mailing list [email protected] http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-core
