From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 90781385E017; Fri, 27 Mar 2020 21:49:19 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 90781385E017 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1585345759; bh=YFhGBh+uB4NTm+9chfhkeaW1/AfVVdGERPg7fZ2dZjs=; h=From:To:Subject:Date:From; b=tRVNLoeJC5dGQihjyUCQ7R5uwm61gyiVfkHJ+He4AHCK+BABH7dvtG/UjP0LvPfFS LikXcfre6FOBxQ9cyq9VqDLrCcXgilClrmK0rULDn7Q+zr6fGgiHxU/Y4IgNbEEt7T CNB3kvqYwPjspcwAWW2Ho4SfVsv/p8D7RilavMoM= From: "jamborm at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/94373] New: 548.exchange2_r run time is 7-12% worse than GCC 9 at -O2 and generic march/mtune Date: Fri, 27 Mar 2020 21:49:19 +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: 10.0 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 cf_gcchost cf_gcctarget 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: Fri, 27 Mar 2020 21:49:19 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D94373 Bug ID: 94373 Summary: 548.exchange2_r run time is 7-12% worse than GCC 9 at -O2 and generic march/mtune Product: gcc Version: 10.0 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: --- Host: x86_64-linux Target: x86_64-linux When compiled with just -O2, SPEC 2017 INTrate benchmark 548.exchange2_r runs slower than when compiled with GCC 9.2. It is: - 8% slower on AMD Zen2-based server CPU (rev. 26b3e568a60) - 12% slower on Intel Cascade Lake server CPU (rev. abe13e1847f) - 7% slower on AMD Zen1-based server CPU (rev. 26b3e568a60) During GCC 10 development cycle the benchmark was relatively noisy and the run time was increasing in many small steps, but between October 7 and November 15 we were doing 3% better than GCC 9 (on Zen2). Specifically the following commit brought about the improvement: commit 806bdf4e40d31cf55744c876eb9f17654de36b99 Author: Richard Biener Date: Mon Oct 7 07:53:45 2019 +0000 re PR tree-optimization/91975 (worse code for small array copy using pointer arithmetic than array indexing) 2019-10-07 Richard Biener PR tree-optimization/91975 * tree-ssa-loop-ivcanon.c (constant_after_peeling): Consistently handle invariants. From-SVN: r276645 But it was undone by its revert: commit f0af4848ac40d2342743c9b16416310d61db85b5 Author: Richard Biener Date: Fri Nov 15 09:09:16 2019 +0000 re PR tree-optimization/92039 (Spurious -Warray-bounds warnings building 32-bit glibc) 2019-11-15 Richard Biener PR tree-optimization/92039 PR tree-optimization/91975 * tree-ssa-loop-ivcanon.c (constant_after_peeling): Revert previous change, treat invariants consistently as non-constant. (tree_estimate_loop_size): Ternary ops with just the first op constant are not optimized away. * gcc.dg/tree-ssa/cunroll-2.c: Revert to state previous to unroller adjustment. * g++.dg/tree-ssa/ivopts-3.C: Likewise. From-SVN: r278281 On the Intel machine, reverting the revert fixes the regression too. 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= )=