From: Philip Craig <philipc@xxxxxxxxxxxx>
Date: Tue, 29 Apr 2008 16:50:56 +1000
> David Miller wrote:
> >> eg what does it do for this:
> >> struct t {
> >> struct s {
> >> u16 a;
> >> u16 b;
> >> } __attribute__(packed);
> >> };
> >
> > 'a' and 'b' cannot be assumed to be aligned in any particular way,
> > and thus byte-at-a-time accesses will be made to them.
>
> Does it ever do anything besides byte access for words on sparc?
>
> Here's my results on ARM, which show that including the packed
> struct in another struct allows gcc to assume alignment.
> I'm not saying this results in pretty code though :-)
Sure, the packed doesn't get inherited by the struct the
sub-struct is in.
But it still means the bit marked packed is going to be
accessed using byte-at-a-time loads and stores.
I guess this is immaterial, as it seems the memset() is the
best solution anyways.
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