From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 4859B3858C53; Mon, 24 Apr 2023 08:46:50 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 4859B3858C53 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1682326010; bh=CD5XVq5UgsRfCeipRNMO0FtOfDkNgrxzuU/2lIZXbMs=; h=From:To:Subject:Date:In-Reply-To:References:From; b=SJx/S/vBRw/2AMt+epRu+sYkz2jgf2DeIJ+ylUkJ4+TK38OtKMJ8N7NJaT6KUaULz XJwjHnPwaPCSIeCHvzi9CPcpvxTRE/dnPaHwugPaGcQom28/emBAgRsCN5sFN7GXW2 KS9uLPnbOGnIeh/WMXihOc6RqZjT2hpHf5knDWjw= From: "amonakov at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/109585] [10/11/12/13/14 regression] Carla/sord miscompiled with -O2 on ARM64 with flexible array member Date: Mon, 24 Apr 2023 08:46:49 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: rtl-optimization X-Bugzilla-Version: 12.1.0 X-Bugzilla-Keywords: alias, wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: amonakov at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 10.5 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: 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: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109585 --- Comment #19 from Alexander Monakov --- Manually minimized testcase for investigation, miscompiled at -O2: struct P { long v; struct P *n; }; struct F { long x; struct P fam[]; }; int f(struct F *f, int i) { struct P *p =3D f->fam; asm("" : "+r"(f): "r"(p)); p->v =3D 0; p->n =3D 0; return f->fam->n !=3D 0; } Trunk emits: f: lea rdx, [rdi+8] mov rax, rdi mov QWORD PTR [rdi+8], 0 cmp QWORD PTR [rax+16], 0 mov QWORD PTR [rdi+16], 0 setne al movzx eax, al ret=