On Wed, Jan 30, 2013 at 08:09:00PM -0600, Kim Phillips wrote: > The savings come mostly from device-tree related code, and some > from drivers.
You forget that IP networking is all big endian, so these will be using the byte swapping too (search it for htons/ntohs/htonl/ntohl). > v2: > - at91 and lpd270 builds fixed by limiting to ARMv6 and above > (i.e., ARM cores that have support for the 'rev' instruction). > Otherwise, the compiler emits calls to libgcc's __bswapsi2 on > these ARMv4/v5 builds (and arch ARM doesn't link with libgcc). Which compiler version? gcc 4.5.4 doesn't do this, except for the 16-bit swap, so I doubt that any later compiler does. > --- a/arch/arm/include/uapi/asm/swab.h > +++ b/arch/arm/include/uapi/asm/swab.h > @@ -50,4 +50,14 @@ static inline __attribute_const__ __u32 > __arch_swab32(__u32 x) > > #endif > > +#if defined(__KERNEL__) && __LINUX_ARM_ARCH__ >= 6 > +#if GCC_VERSION >= 40600 > +#define __HAVE_BUILTIN_BSWAP32__ > +#define __HAVE_BUILTIN_BSWAP64__ > +#endif > +#if GCC_VERSION >= 40800 > +#define __HAVE_BUILTIN_BSWAP16__ > +#endif > +#endif If this is __KERNEL__ only, it should not be in a uapi header. UAPI headers get exported to userland, this is not userland interface code. IT should be in arch/arm/include/asm/swab.h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
