On Wed, Jul 10, 2019 at 12:25 AM Russell King - ARM Linux admin <li...@armlinux.org.uk> wrote: > > On Tue, Jul 09, 2019 at 08:40:51PM +0200, Arnd Bergmann wrote: > > On Tue, Jul 9, 2019 at 8:08 PM 'Nick Desaulniers' via Clang Built > > Linux <clang-built-li...@googlegroups.com> wrote: > > > On Tue, Jul 9, 2019 at 1:41 AM Linus Walleij <linus.wall...@linaro.org> > > > wrote: > > > > > > > I guess this brings up the old question whether the compiler should > > > > be worked around or just considered immature, but as it happens this > > > > > > Definitely a balancing act; we prioritize work based on what's > > > feasible to work around vs must be implemented. A lot of my time is > > > going into validation of asm goto right now, but others are ramping up > > > on the integrated assembler (clang itself can be invoked as a > > > substitute for GNU AS; but there's not enough support to do `make > > > AS=clang` for the kernel just yet). > > > > Note that this bug is the same with both gas and AS=clang, which also > > indicates that clang implemented the undocumented .rep directive > > for compatibility. > > > > Overall I think we are at the point where building the kernel with clang-8 > > is mature enough that we should work around bugs like this where it is > > easy enough rather than waiting for clang-9. > > While both assemblers seem to support both .rept and .rep, might it > be an idea to check what the clang-8 situation is with .rept ?
Good idea. I tried this patch now: --- a/arch/arm/include/asm/mtd-xip.h +++ b/arch/arm/include/asm/mtd-xip.h @@ -15,6 +15,6 @@ #include <mach/mtd-xip.h> /* fill instruction prefetch */ -#define xip_iprefetch() do { asm volatile (".rep 8; nop; .endr"); } while (0) +#define xip_iprefetch() do { asm volatile (".rept 8; nop; .endr"); } while (0) #endif /* __ARM_MTD_XIP_H__ */ Unfortunately that has no effect, clang treats them both the same way. Arnd