[patch] Fix PR 43842

[Ira Rosen]

"H.J. Lu" <hjl.tools@gmail.com> wrote on 22/04/2010 09:07:58 PM:

> From: "H.J. Lu" <hjl.tools@gmail.com>
> To: Ira Rosen/Haifa/IBM@IBMIL
> Cc: gcc-patches@gcc.gnu.org
> Date: 22/04/2010 09:08 PM
> Subject: Re: [patch] Fix PR 43842
>
> On Thu, Apr 22, 2010 at 11:06 AM, Ira Rosen <IRAR@il.ibm.com> wrote:
> >
> > Hi,
> >
> > This patch adds missing support for the case of loop unrolling in SLP
with
> > reductions in update of loop exit phis. In this case the number of
> > generated vector cycles can be greater than SLP group size.
> > This patch also prevents attempts to apply SLP vectorization if there
is
> > only reduction in the loop.
> >
> > Bootstrapped and tested on x86_64-suse-linux. Committed.
> >
> > Ira
> >
> >
> > ChangeLog:
> >
> >      PR tree-optimization/43482
>                                       ^^^^^^^
> Wrong PR #.

Yes, sorry, I fixed it in the ChangeLogs.

Ira

>
>
> H.J.
> >      * tree-vect-loop.c (vect_create_epilog_for_reduction): Handle
> >      loop unrolling in update of exit phis. Fix comment.
> >      * tree-vect-slp.c (vect_analyze_slp): Check that there are at
> >      least two reduction statements in the loop before starting SLP
> >      analysis.
> >
> > testsuite/ChangeLog:
> >
> >      PR tree-optimization/43482
> >      * gcc.dg/vect/pr43842.c: New test.
> >
> >