From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
 id 2AA31383940F; Wed, 11 May 2022 06:21:41 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 2AA31383940F
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/101384] [9/10 Regression] wrong code at -Og and above
 with vector shift/multiply
Date: Wed, 11 May 2022 06:21:40 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 12.0
X-Bugzilla-Keywords: wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: cvs-commit at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P2
X-Bugzilla-Assigned-To: jakub at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 9.5
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-101384-4-zqGty9oBAw@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-101384-4@http.gcc.gnu.org/bugzilla/>
References: <bug-101384-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-BeenThere: gcc-bugs@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-bugs mailing list <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Wed, 11 May 2022 06:21:41 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D101384

--- Comment #13 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-9 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:883690ff6bd8e4f16c871b307cebb13d6c14edcb

commit r9-10092-g883690ff6bd8e4f16c871b307cebb13d6c14edcb
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Tue Jul 20 16:41:29 2021 +0200

    rs6000: Fix up easy_vector_constant_msb handling [PR101384]

    The following gcc.dg/pr101384.c testcase is miscompiled on
    powerpc64le-linux.
    easy_altivec_constant has code to try construct vector constants with
    different element sizes, perhaps different from CONST_VECTOR's mode.  B=
ut
as
    written, that works fine for vspltis[bhw] cases, but not for the vsplti=
sw
    x,-1; vsl[bhw] x,x,x case, because that creates always a V16QImode,
V8HImode
    or V4SImode constant containing broadcasted constant with just the MSB =
set.
    The vspltis_constant function etc. expects the vspltis[bhw] instructions
    where the small [-16..15] or even [-32..30] constant is sign-extended to
the
    remaining step bytes, but that is not the case for the 0x80...00 consta=
nts,
    with step 1 we can't handle e.g.
    { 0x80, 0xff, 0xff, 0xff, 0x80, 0xff, 0xff, 0xff, 0x80, 0xff, 0xff, 0xf=
f,
0x80, 0xff, 0xff, 0xff }
    vectors but do want to handle e.g.
    { 0, 0, 0, 0x80, 0, 0, 0, 0x80, 0, 0, 0, 0x80, 0, 0, 0, 0x80 }
    and similarly with copies 1 we do want to handle e.g.
    { 0x80808080, 0x80808080, 0x80808080, 0x80808080 }.

    This is a simpler version of the fix for backports, which limits the
EASY_VECTOR_MSB case
    matching to step =3D=3D 1 && copies =3D=3D 1, because that is the only =
case the
    splitter handles correctly.

    2021-07-20  Jakub Jelinek  <jakub@redhat.com>

            PR target/101384
            * config/rs6000/rs6000.c (vspltis_constant): Accept EASY_VECTOR=
_MSB
            only if step and copies are equal to 1.

            * gcc.dg/pr101384.c: New test.

    (cherry picked from commit dc386b020869ad0095cf58f8c76a40ea457e7a2c)=