Re: [RFC] Documentation about unaligned memory access

Luciano Rocha
2007-11-24T18:28:38Z

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On Sat, Nov 24, 2007 at 06:35:25PM +0100, Pierre Ossman wrote:
> On Sat, 24 Nov 2007 17:22:36 +0000
> Luciano Rocha <strange@nsk.no-ip.org> wrote:
>
> > On Sat, Nov 24, 2007 at 05:19:31PM +0100, Pierre Ossman wrote:
> > > It most certainly does not. gcc will assume that an int* has int alignment. memcpy() is a builtin, which gcc can translate to pretty much anything. And C specifies that a pointer to foo, will point to a real object of type foo, so gcc can't be blamed for the unsafe typecasts. I have tested this the hard way, so this is not just speculation.
> >
> > Yes, on *int and other assumed aligned pointers, gcc uses its internal
> > version.
> >
> > However, my point is that those pointers, unless speaking of packed
> > structures, can safely be assumed aligned, while char*/void* can't.
> >
>
> I get the sensation we're violently in agreement here, just misunderstanding each other. :)

That's it. :)

Sorry for the noise,...

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