On Fri, Jul 24, 2009 at 11:23:11AM -0700, Frans Pop wrote: > On Friday 24 July 2009, Peter Chubb wrote: > > >>>>> "Sam" == Sam Ravnborg <sam@xxxxxxxxxxxx> writes: > > Sam> The above change is correct. But I really wonder if the original > > Sam> code was correct? Do we really only want to use the -mtune > > Sam> options for this specific gcc version? If this is indeed the > > Sam> case this deserves a comment explaning this. > > > > I suspect it should be all compilers after this one. -mtune=mckinley > > didn't work very well in the early gcc 3 compilers and didn't exist in > > version 2. > > How would you like to handle that? As it is essentially a separate issue, > my suggestion would be: apply my patch as is and then (if needed) commit > a separate patch to fix the incorrect comparisons on top. Between GCC version 3.4.0 and 4.3.3 (including 3.4.0 and 4.3.3), -mtune=merced is implemented in GCC. Starting from 4.4.0, -mtune=merced is deprecated. Even implemented in versions between 3.4.0 and 4.3.3, the -mtune=merced feature has been broken in some of the versions. For example, GCC 4.1.2 reports interanl tuning function errors during kernel building with -mtune=merced. Or GCC Bugzilla 16130 reports another -mtune=merced issue on GCC 3.4.1. So I would remove the -mtune=merced from IA64 kernel build. Without this option, kernel on Merced will remain the same except losing an unstable and out-of-date performance tunning feature. Since GCC version 3.4.0, -mtune=mckinley has been implemented. The -mtune=mckinley option functions the same as mtune=itanium2. And mtune=itanium2 is the default option. So we don't need to add mtune=mckinley either since its been the default option in any GCC version which implements this option. Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx> --- arch/ia64/Makefile | 5 ----- 1 files changed, 5 deletions(-) diff --git a/arch/ia64/Makefile b/arch/ia64/Makefile index 58a7e46..e7cbaa0 100644 --- a/arch/ia64/Makefile +++ b/arch/ia64/Makefile @@ -41,11 +41,6 @@ $(error Sorry, you need a newer version of the assember, one that is built from ftp://ftp.hpl.hp.com/pub/linux-ia64/gas-030124.tar.gz) endif -ifeq ($(call cc-version),0304) - cflags-$(CONFIG_ITANIUM) += -mtune=merced - cflags-$(CONFIG_MCKINLEY) += -mtune=mckinley -endif - KBUILD_CFLAGS += $(cflags-y) head-y := arch/ia64/kernel/head.o arch/ia64/kernel/init_task.o -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
