[patch] Fix PR tree-optmization/50413

[H.J. Lu]

On Mon, Sep 19, 2011 at 4:46 AM, Ira Rosen <ira.rosen@linaro.org> wrote:
> Hi,
>
> When we can't vectorize a certain statement in SLP we mark it as not
> vectorizable and continue with the analysis. This is wrong when the
> reason for the failure is that we can't analyze a data-ref, because
> this way we may miss a data dependence. This patch fails SLP if the
> data-refs analysis fails.
>
> Bootstrapped and tested on powerpc64-suse-linux and i486-linux-gnu.
> Committed to trunk.

On Linux/x86, I got

FAIL: g++.dg/vect/slp-pr50413.cc scan-tree-dump-times slp "basic block
vectorized using SLP" 0

>
>        PR tree-optimization/50413
>        * tree-vect-data-refs.c (vect_analyze_data_refs): Fail to vectorize
>        a basic block if one of its data-refs can't be analyzed.
>
> testsuite/ChangeLog:
>
>        PR tree-optimization/50413
>        * g++.dg/vect/vect.exp: Run slp-pr* tests with
>        -fdump-tree-slp-details.  Run other tests with
>        -fdump-tree-vect-details.
>        * g++.dg/vect/slp-pr50413.cc: New.
>



-- 
H.J.