[Bug target/56865] [4.9 regression] FAIL: gcc.dg/vect/vect-42.c scan-tree-dump-times vect "Vectorizing an unaligned access" 4

["rguenther at suse dot de" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56865

--- Comment #3 from rguenther at suse dot de <rguenther at suse dot de> 2013-05-02 07:37:55 UTC ---
On Wed, 1 May 2013, wschmidt at gcc dot gnu.org wrote:

> 
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56865
> 
> Bill Schmidt <wschmidt at gcc dot gnu.org> changed:
> 
>            What    |Removed                     |Added
> ----------------------------------------------------------------------------
>                  CC|                            |rguenth at gcc dot gnu.org,
>                    |                            |wschmidt at gcc dot gnu.org
> 
> --- Comment #2 from Bill Schmidt <wschmidt at gcc dot gnu.org> 2013-05-01 21:58:09 UTC ---
> I've reproduced this as well.  Additionally, gcc.dg/vect/vect-96.c fails
> similarly.  Both tests began failing at r196872:
> 
> 2013-03-21  Richard Biener  <rguenther@suse.de>
> 
>     * tree-vect-data-refs.c (vect_update_interleaving_chain): Remove.
>     (vect_insert_into_interleaving_chain): Likewise.
>     (vect_drs_dependent_in_basic_block): Inline ...
>     (vect_slp_analyze_data_ref_dependence): ... here.  New function,
>     split out from ...
>     (vect_analyze_data_ref_dependence): ... here.  Simplify.
>     (vect_check_interleaving): Simplify.
>     (vect_analyze_data_ref_dependences): Likewise.  Split out ...
>     (vect_slp_analyze_data_ref_dependences): ... this new function.
>     (dr_group_sort_cmp): New function.
>     (vect_analyze_data_ref_accesses): Compute data-reference groups
>     here instead of in vect_analyze_data_ref_dependence.  Use
>     a more efficient algorithm.
>     * tree-vect-slp.c (vect_slp_analyze_bb_1): Use
>     vect_slp_analyze_data_ref_dependences.  Call
>     vect_analyze_data_ref_accesses earlier.
>     * tree-vect-loop.c (vect_analyze_loop_2): Likewise.
>     * tree-vectorizer.h (vect_analyze_data_ref_dependences): Adjust.
>     (vect_slp_analyze_data_ref_dependences): New prototype.
> 
> Richi, I think this commit was not intended to have any functional effect -- is
> that correct?

Correct.  Dumping order is affected by the patch though, thus if
we previously disabled vectorization at some point the dumping
before that can be affected due to the re-ordering.