[PATCH, RFC 09/22] crypto: lz4: don't build on ARM

[Arnd Bergmann]

On Friday 03 May 2013, Chanho Min wrote:
> >It is not currently possible to build the LZ4 code on ARM, so let's
> >remove that option in Kconfig for now.
> >
> >lib/built-in.o: In function `lz4_compress64kctx':
> > lib/lz4/lz4_compress.c:339: undefined reference to `__ctzsi2'
> >lib/built-in.o: In function `lz4_compressctx':
> > lib/lz4/lz4_compress.c:157: undefined reference to `__ctzsi2'
> >lib/built-in.o: In function `lz4hc_commonlength':
> > lib/lz4/lz4hc_compress.c:102: undefined reference to `__ctzsi2'
> > lib/lz4/lz4hc_compress.c:102: undefined reference to `__ctzsi2'
> >lib/built-in.o: In function `lz4hc_insertandgetwidermatch':
> > lib/lz4/lz4hc_compress.c:230: undefined reference to `__ctzsi2'
> 
> Please, let me know the gcc version and tested defconfig.
> I didn't have any problem to build with gcc 4.6.4 on armv7.
> Some architecture need libgcc functions for __builtin_clz/ctz.
> Porting them to lib is in progress:
> http://marc.info/?l=linux-kernel&m=136748861811956&w=2
> But, It doesn't happen on ARM, PowerPC and x86.

I tested with gcc-4.8 and random configurations. I've tried it
again now and can't reproduce it at the moment. I'll try building
more random configurations until I have nailed down the problem.

Sorry about this, I should have been more careful about my
original conclusion here.

	Arnd