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Re: -ftree-vectorize can't vectorize plus?
- From: Dorit Nuzman <DORIT at il dot ibm dot com>
- To: Dorit Nuzman <DORIT at il dot ibm dot com>
- Cc: "Devang Patel" <devang dot patel at gmail dot com>, gcc at gcc dot gnu dot org
- Date: Thu, 21 Sep 2006 09:31:48 +0300
- Subject: Re: -ftree-vectorize can't vectorize plus?
opened a missed optimization PR so that I won't forget about it - PR29160
dorit
> "Devang Patel" <devang.patel@gmail.com> wrote on 11/09/2006 07:30:17 PM:
>
> > > Can these type casts (from uchar to schar and back) be cleaned away
> > > by some pass before vectorization, or do we need to teach the
> vectorizer
> > > to ignore such type casts?
> >
> > This was considered as tree-combiner's responsibility. However, I do
not
> > know what is the current state and plan of tree-combiner pass.
> tree-combiner
> > pass, along with other combining activites, will remove unnecessary
> > cast (if possible).
> >
>
> so the stuff in tree-ssa-forwprop:eliminate_unnecessary_casts in
> autovect-branch is supposed to go under this tree-combiner pass as well,
or
> do you plan to merge it to mainline some time?
>
> I could add this pattern to the vectorizer's idiom-recognition pass -
it's
> like a tree-combiner I guess, except it's enabled from within the
> vectorizer (and looks only for patterns that can help the vectorizer),
and
> doesn't change anything if the code doesn't end up getting vectorized. I
> imagine this should be only a temporary solution, cause this cleanup is
> potentially useful regardless of vectorization.
>
> dorit
>
> > -
> > Devang
>