From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 91CAC3853821; Thu, 14 Jul 2022 09:08:42 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 91CAC3853821 From: "jamborm at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/106293] New: 456.hmmer at -Ofast -march=native regressed by 19% on zen2 and zen3 in July 2022 Date: Thu, 14 Jul 2022 09:08:42 +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: jamborm at gcc dot gnu.org 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 cc blocked target_milestone Message-ID: 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 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 14 Jul 2022 09:08:42 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D106293 Bug ID: 106293 Summary: 456.hmmer at -Ofast -march=3Dnative regressed by 19% on zen2 and zen3 in July 2022 Product: gcc Version: 12.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: jamborm at gcc dot gnu.org CC: rguenth at gcc dot gnu.org Blocks: 26163 Target Milestone: --- The benchmark 456.hmmer from SPECINT 2006 suite has regressed on zen2 when compiled with -Ofast -march=3Dnative, with or without LTO. See: https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=3D301.180.0 https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=3D289.180.0 On zen3, LNT only reported a similar regression with LTO: https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=3D476.180.0 There may be some effect also on the Kabylake: https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=3D2.180.0 On Zen2 (with LTO), I have manually bisected the regression to: d2a898666609452ef79a14feae1cadc3538e4b45 is the first bad commit commit d2a898666609452ef79a14feae1cadc3538e4b45 Author: Richard Biener Date: Tue Jun 21 16:17:58 2022 +0200 Put virtual operands into loop-closed SSA When attempting to manually update SSA form after high-level loop transforms such as loop versioning it is helpful when the loop-closed SSA form includes virtual operands. While we have the special rewrite_virtuals_into_loop_closed_ssa function that doesn't presently scale, invoking update_ssa by itself. So the following makes the regular loop-closed SSA form also cover virtual operands. For users of loop_version this allows to use cheaper TODO_update_ssa_no_phi, skipping dominance frontier compute (for the whole function) and iterated dominance frontiers for each copied def. Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D26163 [Bug 26163] [meta-bug] missed optimization in SPEC (2k17, 2k and 2k6 and 95= )=