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. - k _______________________________________________ Openembedded-core mailing list [email protected] http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-core
