[Bug testsuite/51693] New XPASSes in vectorizer testsuite on powerpc64-suse-linux

[michael.v.zolotukhin at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51693

--- Comment #1 from Michael Zolotukhin <michael.v.zolotukhin at gmail dot com> 2011-12-28 11:08:36 UTC ---
I though that if {vect_aligned_arrays} isn't true, than arrays could
be aligned even after peeling - that's why I added such check.
Unfortunately, I can't reproduce these fails, as I have no PowerPC. By
the way, if arrays aren't aligned on Power, why does GCC produce such
messages - does it really try to peel something? Maybe we should just
refine the check?
Anyway, if everything is ok with the tests (in original version) and
with gcc itself - we could check not for vect_aligned_arrays, but for
AVX. Please check
http://gcc.gnu.org/ml/gcc-patches/2011-12/msg01600.html and the
attached to that letter patch.

Thanks, Michael


On 28 December 2011 14:51, irar at il dot ibm.com
<gcc-bugzilla@gcc.gnu.org> wrote:
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51693
>
>             Bug #: 51693
>           Summary: New XPASSes in vectorizer testsuite on
>                    powerpc64-suse-linux
>    Classification: Unclassified
>           Product: gcc
>           Version: 4.7.0
>            Status: UNCONFIRMED
>          Severity: normal
>          Priority: P3
>         Component: testsuite
>        AssignedTo: unassigned@gcc.gnu.org
>        ReportedBy: irar@il.ibm.com
>                CC: michael.v.zolotukhin@gmail.com
>              Host: powerpc64-suse-linux
>            Target: powerpc64-suse-linux
>             Build: powerpc64-suse-linux
>
>
> Revision 182583 http://gcc.gnu.org/viewcvs?view=revision&revision=182583 caused
> several XPASSes on powerpc64-suse-linux:
>
> XPASS: gcc.dg/vect/vect-multitypes-1.c scan-tree-dump-times vect "Alignment of
> access forced using peeling" 2
> XPASS: gcc.dg/vect/vect-multitypes-1.c scan-tree-dump-times vect "Vectorizing
> an unaligned access" 4
> XPASS: gcc.dg/vect/vect-peel-3.c scan-tree-dump-times vect "Vectorizing an
> unaligned access" 1
> XPASS: gcc.dg/vect/vect-peel-3.c scan-tree-dump-times vect "Alignment of access
> forced using peeling" 1
> XPASS: gcc.dg/vect/vect-multitypes-1.c -flto scan-tree-dump-times vect
> "Alignment of access forced using peeling" 2
> XPASS: gcc.dg/vect/vect-multitypes-1.c -flto scan-tree-dump-times vect
> "Vectorizing an unaligned access" 4
> XPASS: gcc.dg/vect/vect-peel-3.c -flto scan-tree-dump-times vect "Vectorizing
> an unaligned access" 1
> XPASS: gcc.dg/vect/vect-peel-3.c -flto scan-tree-dump-times vect "Alignment of
> access forced using peeling" 1
> XPASS: gcc.dg/vect/no-section-anchors-vect-69.c scan-tree-dump-times vect
> "Alignment of access forced using peeling" 2
>
> The reason is that {!vect_aligned_arrays} was added to xfail of the above
> checks, while vect_aligned_arrays is false for power.
>
> Changing that, i.e.:
> Index: ../../lib/target-supports.exp
> ===================================================================
> --- ../../lib/target-supports.exp       (revision 182703)
> +++ ../../lib/target-supports.exp       (working copy)
> @@ -3222,7 +3222,8 @@ proc check_effective_target_vect_aligned_arrays {
>                 set et_vect_aligned_arrays_saved 1
>            }
>        }
> -        if [istarget spu-*-*] {
> +        if {[istarget spu-*-*]
> +           || [istarget powerpc*-*-*] } {
>            set et_vect_aligned_arrays_saved 1
>        }
>     }
>
> fixes the XPASSes and doesn't cause any problems (on powerpc64-suse-linux), but
> AFAIU arrays are not always vector aligned on power, so this is not a good
> idea, unless we change the definition of
> check_effective_target_vect_aligned_arrays.
>
> What was the purpose of adding {!vect_aligned_arrays} to these tests? If
> peeling is impossible on AVX because arrays are never vector aligned, maybe we
> need a new target check instead of vect_aligned_arrays?
>
> --
> Configure bugmail: http://gcc.gnu.org/bugzilla/userprefs.cgi?tab=email
> ------- You are receiving this mail because: -------
> You are on the CC list for the bug.