Re: [PATCH] ARM: Ensure that NEON code always compiles with Clang

From: Arnd Bergmann
Date: Mon Mar 11 2019 - 17:37:05 EST


On Mon, Mar 11, 2019 at 5:49 PM Ard Biesheuvel
<ard.biesheuvel@xxxxxxxxxx> wrote:
>
> On Mon, 11 Mar 2019 at 17:22, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> >
> > On Sat, Dec 15, 2018 at 10:24 PM Nathan Chancellor
> > <natechancellor@xxxxxxxxx> wrote:
> > > endif
> > > diff --git a/arch/arm/lib/xor-neon.c b/arch/arm/lib/xor-neon.c
> > > index a6741a895189..4600b62d845f 100644
> > > --- a/arch/arm/lib/xor-neon.c
> > > +++ b/arch/arm/lib/xor-neon.c
> > > @@ -14,7 +14,7 @@
> > > MODULE_LICENSE("GPL");
> > >
> > > #ifndef __ARM_NEON__
> > > -#error You should compile this file with '-mfloat-abi=softfp -mfpu=neon'
> > > +#error You should compile this file with '-march=armv7-a -mfloat-abi=softfp -mfpu=neon'
> > > #endif
> > >
> >
> > I see this patch has made it in now, but I also see two other problems with the
> > same file that prevent it from working right with clang:
> >
> > - it triggers #warning This code requires at least version 4.6 of GCC
>
> What is currently the oldest GCC we support for ARM?

Linux overall requires gcc-4.6, so we could just as well drop this
check, good point.

Arnd