[Bug middle-end/110142] New: [14 Regression] x264 from SPECCPU 2017 miscompares from g:2f482a07365d9f4a94a56edd13b7f01b8f78b5a0

[Bug middle-end/110142] New: [14 Regression] x264 from SPECCPU 2017 miscompares from g:2f482a07365d9f4a94a56edd13b7f01b8f78b5a0

[tnfchris at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110142

            Bug ID: 110142
           Summary: [14 Regression] x264 from SPECCPU 2017 miscompares
                    from g:2f482a07365d9f4a94a56edd13b7f01b8f78b5a0
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tnfchris at gcc dot gnu.org
                CC: avieira at gcc dot gnu.org
  Target Milestone: ---
              Host: aarch64*
            Target: aarch64*
             Build: aarch64*

Benchmark miscompiles after g:2f482a07365d9f4a94a56edd13b7f01b8f78b5a0

From 2f482a07365d9f4a94a56edd13b7f01b8f78b5a0 Mon Sep 17 00:00:00 2001
From: Andre Vieira <andre.simoesdiasvieira@arm.com>
Date: Mon, 5 Jun 2023 17:53:10 +0100
Subject: [PATCH] internal-fn,vect: Refactor widen_plus as internal_fn

     DEF_INTERNAL_WIDENING_OPTAB_FN and DEF_INTERNAL_NARROWING_OPTAB_FN
are like DEF_INTERNAL_SIGNED_OPTAB_FN and DEF_INTERNAL_OPTAB_FN
respectively. With the exception that they provide convenience wrappers
for a single vector to vector conversion, a hi/lo split or an even/odd
split.  Each definition for <NAME> will require either signed optabs
named <UOPTAB> and <SOPTAB> (for widening) or a single <OPTAB> (for
narrowing) for each of the five functions it creates.

[Bug middle-end/110142] [14 Regression] x264 from SPECCPU 2017 miscompares from g:2f482a07365d9f4a94a56edd13b7f01b8f78b5a0

[avieira at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110142

--- Comment #1 from avieira at gcc dot gnu.org ---
Found the issue to be with passing a subtype to vect_recog_widen_op_pattern in
vect_recog_widen_{plus,minus}_pattern where we didn't before. Removing those
and letting it default to a NULL pointer seems to fix the codegen issue.  Will
test patches locally and send in patch when done.

[Bug middle-end/110142] [14 Regression] x264 from SPECCPU 2017 miscompares from g:2f482a07365d9f4a94a56edd13b7f01b8f78b5a0

[tnfchris at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110142

--- Comment #2 from Tamar Christina <tnfchris at gcc dot gnu.org> ---
Thank you!

[Bug middle-end/110142] [14 Regression] x264 from SPECCPU 2017 miscompares from g:2f482a07365d9f4a94a56edd13b7f01b8f78b5a0

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110142

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |14.0

[Bug middle-end/110142] [14 Regression] x264 from SPECCPU 2017 miscompares from g:2f482a07365d9f4a94a56edd13b7f01b8f78b5a0

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110142

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Andre Simoes Dias Vieira
<avieira@gcc.gnu.org>:

https://gcc.gnu.org/g:3ad0ef34ccbe656a7a9e5962fe1173226104174a

commit r14-1708-g3ad0ef34ccbe656a7a9e5962fe1173226104174a
Author: Andre Vieira <andre.simoesdiasvieira@arm.com>
Date:   Mon Jun 12 10:30:39 2023 +0100

    vect: Don't pass subtype to vect_widened_op_tree where not needed [PR
110142]

    This patch fixes an issue introduced by
    g:2f482a07365d9f4a94a56edd13b7f01b8f78b5a0, where a subtype was beeing
passed
    to vect_widened_op_tree, when no subtype was to be used. This lead to an
    errorneous use of IFN_VEC_WIDEN_MINUS.

    gcc/ChangeLog:

            PR middle-end/110142
            * tree-vect-patterns.cc (vect_recog_widen_op_pattern): Don't pass
            subtype to vect_widened_op_tree and remove subtype parameter, also
            remove superfluous overloaded function definition.
            (vect_recog_widen_plus_pattern): Remove subtype parameter and dont
pass
            to call to vect_recog_widen_op_pattern.
            (vect_recog_widen_minus_pattern): Likewise.

    gcc/testsuite/ChangeLog:

            * gcc.dg/vect/pr110142.c: New test.

[Bug middle-end/110142] [14 Regression] x264 from SPECCPU 2017 miscompares from g:2f482a07365d9f4a94a56edd13b7f01b8f78b5a0

[avieira at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110142

avieira at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |FIXED

--- Comment #4 from avieira at gcc dot gnu.org ---
I believe that fixes the issue.