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Re: [PATCH 1/3] Fix PR46029: reimplement if-convert stores.


On Wed, 10 Nov 2010, Sebastian Pop wrote:

> Hi Richi,
> 
> On Fri, Nov 5, 2010 at 11:08, Sebastian Pop <sebpop@gmail.com> wrote:
> >> Note that if you want to make vectorization happy you would need
> >> to ensure that for
> >>
> >> ?if (x)
> >> ? ?a[i] = ...;
> >>
> >> the scratchpad you'll end up using will have the _same_ alignment
> >> as a[i] (same or larger for all offsets). ?Using a local array
> >> of chars should make it possible for the vectorizer to adjust
> >> its alignment if needed.
> >>
> >
> > Ok, thanks for the recommendation, I will try to use a local array.
> 
> Do you happen to know how to declare an automatic variable?
> 
> I was looking at the code in tree-switch-conversion.c:build_one_array.
> Does that look the right approach to statically declare the scratchpad
> on the stack?

As simple as

var = create_tmp_var (type, NULL_TREE);

switch-conversion builds a local static array, not an automatic var.

Richard.

-- 
Richard Guenther <rguenther@suse.de>
Novell / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746 - GF: Markus Rex

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