Re: [PATCHv2 bpf-next 1/3] bpf, tests: tweak endianness selection

On Wed, Mar 20, 2019 at 09:53:33PM +0900, Sergey Senozhatsky wrote:

Not all compilers have __builtin_bswap16() and __builtin_bswap32(), thus not all compilers are able to compile the following code:

    (__builtin_constant_p(x) ? \
            ___constant_swab16(x) : __builtin_bswap16(x))

That's the reason why bpf_ntohl() doesn't work on GCC < 4.8, for instance:

nack to fixes to support such old compilers.