From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 695EE3858D38; Thu, 11 Apr 2024 21:52:54 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 695EE3858D38 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1712872374; bh=r9zAqW+McBUtGQ9V4PjTt/X3n/iz38WOlvMzd7LtJY0=; h=From:To:Subject:Date:In-Reply-To:References:From; b=SsBEr5of4VYWono8ZeWQTief1wezs/qZVQuxZJAjIbynJ+7mGGuwZ25nYCTccV/X0 tyKrwcZgAbTKulcnAROxMrmMtpTA8y7XJqd8+hERQKaoIjq4/vpqlhmkz78W2qaH/3 ziI1+leH0GAAVyynA1sDI/5bd3tdrhFJhNObL2dg= From: "tnfchris at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/114403] [14 regression] LLVM miscompiled with -O3 -march=znver2 -fno-vect-cost-model since r14-6822-g01f4251b8775c8 Date: Thu, 11 Apr 2024 21:52:54 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: tree-optimization X-Bugzilla-Version: 14.0 X-Bugzilla-Keywords: needs-reduction, wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: tnfchris at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Resolution: X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: tnfchris at gcc dot gnu.org X-Bugzilla-Target-Milestone: 14.0 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=3D114403 --- Comment #22 from Tamar Christina --- note that due to the secondary exit the actual full vector iteration count = is 8 scalar elements at VF=3D4 =3D=3D 2. And it's this boundary condition where we fail, since ceil (8/4) =3D=3D 2. = any other value would have done the partial vector iteration. Basically final_iter_may_be_partial ends up being ignored.=