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Re: [PATCH] Add vector cost model density heuristic
On Mon, 11 Jun 2012, David Edelsohn wrote:
> On Mon, Jun 11, 2012 at 7:40 AM, Richard Guenther <rguenther@suse.de> wrote:
>
> > Hmm. ?I don't like this patch or its general idea too much. ?Instead
> > I'd like us to move more of the cost model detail to the target, giving
> > it a chance to look at the whole loop before deciding on a cost. ?ISTR
> > posting the overall idea at some point, but let me repeat it here instead
> > of trying to find that e-mail.
>
> Richard,
>
> Allowing the target to see the entire loop and have more control over
> the cost model is a fine goal, but the current code is using incorrect
> heuristics. Requiring a complete re-write of the auto-vectorizer cost
> model should not be a requirement for fixing the current code.
If fixing the current code adds more "magic" hooks at the wrong spot
then yes, in stage1 I can make you think about a more proper solution
to the issue.
Richard.