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On Wed, 2006-01-11 at 00:00 -0800, David S. Miller wrote: > From: Ulrich Drepper <drepper@redhat.com> > Date: Tue, 10 Jan 2006 14:02:52 -0800 > > > I just saw this in a patch: > > > > + if (ntohs(ih->frag_off) & IP_OFFSET) > > + return EBT_NOMATCH; > > > > This isn't optimal, it requires a byte switch little endian machines. > > The compiler isn't smart enough. It would be better to use > > > > if (ih->frag_off & ntohs(IP_OFFSET)) > > > > where the byte-swap can be done at compile time. This is kind of ugly, > > I guess, so maybe a dedicate macro > > > > net_host_bit_p(ih->frag_off, IP_OFFSET) > > The first suggestion isn't considered ugly, and the best form is: > > if (ih->frag_off & __constant_htons(IP_OFFSET)) why this __constant_htons and not just plain htons ?? htons() gets auto-remapped to that anyway via the builtin "is this a constant" thing...... and to be honest htons() is more readable. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||||
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