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 584513858D32; Sun, 21 Apr 2024 11:47:26 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 584513858D32
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1713700046;
	bh=KfzZA6IASPG3j6PS+wvZAczHN5I3aijR8HQrXcsp5J0=;
	h=From:To:Subject:Date:From;
	b=oRiksFPPfh0y2VZu2Cpjjc0ZaWi5WyBfeSzcmFuhKLwksViM0/Q4LbBsaNm6lrkB2
	 eDlZboKoEta2YOeygfRrgtBL8+XTAljvP61nMocUWFICMC5FAn45bG53es67U1SWXS
	 LE4OaZR7BGj2XoszWeKkH6uYoHVibhNbKY9UxC5A=
From: "zhendong.su at inf dot ethz.ch" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/114793] New: wrong code at -O1 with
 "-fschedule-insns2 -fselective-scheduling2" on x86_64-linux-gnu (the
 generated code hangs)
Date: Sun, 21 Apr 2024 11:47:25 +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: unknown
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: zhendong.su at inf dot ethz.ch
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-114793-4@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
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D114793

            Bug ID: 114793
           Summary: wrong code at -O1 with "-fschedule-insns2
                    -fselective-scheduling2" on x86_64-linux-gnu (the
                    generated code hangs)
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zhendong.su at inf dot ethz.ch
  Target Milestone: ---

It seems to be a recent regression as it does not reproduce with 13.2 and
earlier.

Compiler Explorer: https://godbolt.org/z/b3cc1MqP9

[538] % gcctk -v
Using built-in specs.
COLLECT_GCC=3Dgcctk
COLLECT_LTO_WRAPPER=3D/local/suz-local/software/local/gcc-trunk/libexec/gcc=
/x86_64-pc-linux-gnu/14.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk/configure --disable-bootstrap
--enable-checking=3Dyes --prefix=3D/local/suz-local/software/local/gcc-trunk
--enable-sanitizers --enable-languages=3Dc,c++ --disable-werror --enable-mu=
ltilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 14.0.1 20240421 (experimental) (GCC)=20
[539] %=20
[539] % gcctk -O0 small.c
[540] % ./a.out
[541] %=20
[541] % gcctk -O1 -fschedule-insns2 -fselective-scheduling2 small.c
[542] % timeout -s 9 10 ./a.out
Killed
[543] %=20
[543] % cat small.c
int printf(const char *, ...);
volatile int a;
int b, c, d =3D 1, e, f;
int main() {
  int g =3D 1;
  for (; b; b -=3D d)
    g =3D e;
  for (; c < 2; c++) {
    if (g) {
      if (!d)
        printf("%d", f);
      continue;
    }
    a;
  }
  return 0;
}=