On Thu, 19 Apr 2007 16:14:23 +0200
Eric Dumazet <dada1@cosmosbay.com> wrote:
> On Wed, 18 Apr 2007 13:04:22 -0700 (PDT)
> David Miller <davem@davemloft.net> wrote:
>
> >
> > Although I don't think gcc does anything fancy since we don't
> > use memcmp(). It's a tradeoff, we'd like to use unsigned long
> > comparisons when both objects are aligned correctly but we also
> > don't want it to use any more than one potentially mispredicted
> > branch.
>
> Again, memcmp() *cannot* be optimized, because its semantic is to compare bytes.
>
> memcpy() can take into account alignement if known at compile time, not memcmp()
>
> http://lists.openwall.net/netdev/2007/03/13/31
It can if we order bytes in the bridge id properly. See ktime_t for example.
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