On Tuesday 08 February 2011 17:32:29 Russell King - ARM Linux wrote: > On Tue, Feb 08, 2011 at 04:17:58PM +0100, Arnd Bergmann wrote: > > On Tuesday 08 February 2011, Dave Martin wrote: > > > CFLAGS_cpu_specific_object.o += -march=armv7-a > > > > > > Whether it's safe to do it depends on whether code from that file > > > could ever get run on other processors. I'm not so sure of the answer > > > to that..., but perhaps someone else has a better idea. > > > > We already do this a lot from arch/arm/mm/Makefile, and those > > files are typically just one function per file, so they can easily > > be proven to be safe that way. > > No, we do that with assembly files. It doesn't work soo well with > C files as we really don't want GCC itself to generate v7 instructions > unless we explicitly ask for them. > > The other issue here is that somtimes generating code with different > -march options leads to the linker refusing to link them together... Ok, I see. Is that a bug in existing toolchains, or something more fundamental? I would have expected that you could at least mix all compiler options that don't impact the ABI or the instruction set like -mthumb. Also, I think we can still build with e.g. "-march=armv6 -Wa,-march=armv7", which should tell the compiler to only emit armv6 instructions, but make the assembler more permissive for inline assembly. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
