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Re: Vector alignment tracking
On Thu, Oct 13, 2011 at 6:57 PM, Andi Kleen <andi@firstfloor.org> wrote:
>> Or I am missing someting?
>
> I often see the x86 vectorizer with -mtune=generic generate a lot of
> complicated code just to adjust for potential misalignment.
>
> My thought was just if the alias oracle knows what the original
> declaration is, and it's available for changes (e.g. LTO), it would be
> likely be better to just add an __attribute__((aligned()))
> there.
>
> In the general case it's probably harder, you would need some
> cost model to decide when it's worth it.
>
> Your approach of course would still be needed for cases where this
> isn't possible. But it sounded like the infrastructure you're building
> could in principle do both.
The vectorizer already does that.
Richard.
> -Andi
>