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 0A3913858C83; Tue, 15 Feb 2022 18:01:24 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0A3913858C83
From: "vsevolod.livinskij at frtk dot ru" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/104551] New: Wrong code with -O3 for
 skylake-avx512, icelake-server, and sapphirerapids
Date: Tue, 15 Feb 2022 18:01:23 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: tree-optimization
X-Bugzilla-Version: 12.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: vsevolod.livinskij at frtk dot ru
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status
 bug_severity priority component assigned_to reporter target_milestone
Message-ID: <bug-104551-4@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: Tue, 15 Feb 2022 18:01:24 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D104551

            Bug ID: 104551
           Summary: Wrong code with -O3 for skylake-avx512,
                    icelake-server, and sapphirerapids
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vsevolod.livinskij at frtk dot ru
  Target Milestone: ---

Reproducer (I was not able to merge it into a single file):
// func.cpp
extern unsigned var_11, var_178;
extern unsigned char arr_492[];
void test() {
  for (bool a =3D 0; a < (bool)var_11; a =3D 2)
    for (unsigned b =3D 0; b < var_11;
         b +=3D 1)
      var_178 =3D arr_492[b] ? arr_492[b] : (char) b;
}

// driver.cpp=20
unsigned int var_11 =3D 16U;
unsigned int var_178 =3D 0;
unsigned char arr_492 [16];

void test();

int main() {
    for (int i =3D 0; i < 16; ++i)
        arr_492 [i] =3D (unsigned char)128;
    test();
    __builtin_printf("%u\n", var_178);
    if (var_178 !=3D 128)
        __builtin_abort();
    return 0;
}

Error:
>$ g++ -O0 func.cpp driver.cpp -march=3Dskylake-avx512 && sde -skx -- ./a.o=
ut=20
128
>$ g++ -O3 func.cpp driver.cpp -march=3Dskylake-avx512 && sde -skx -- ./a.o=
ut=20
4294967168
Aborted (core dumped)

g++ (git://gcc.gnu.org/git/gcc.git:master
58aeb75d4097010ad9bb72b964265b18ab284f93) 12.0.1 20220213 (experimental)=