Messages in this thread | | | Date | Fri, 19 Feb 2016 12:08:23 -0500 (EST) | From | Nicolas Pitre <> | Subject | Re: [PATCH 1/3] [RESEND] ARM: pass -march=armv7-a when building NEON files with clang |
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On Fri, 19 Feb 2016, Arnd Bergmann wrote:
> On Thursday 18 February 2016 12:31:35 Nicolas Pitre wrote: > > On Thu, 18 Feb 2016, Arnd Bergmann wrote: > > > > > clang ignores the -mfpu=neon flag when building with -march=armv6: > > > > > > In file included from lib/raid6/neon1.c:27: > > > clang/3.8.0/include/arm_neon.h:28:2: error: "NEON support not enabled" > > > > > > There is no real need to build the file with -march=armv6 in a > > > multi-CPU enabled kernel, as nothing in here will ever get called > > > on an ARMv6 CPU. Adding -march=armv7 doesn't hurt and can only > > > improve the code quality. > > > > Is this enough to override a previous -mfpu for gcc? > > I did not see any build failures on gcc with this, so I assume it > has no effect. I could move the -march=armv7-a in front of > -mfpu=neon if you think that would be safer though.
I don't know what's safer. That's why I'm asking. :-)
Nicolas
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