From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by sourceware.org (Postfix) with ESMTP id BA1A03858D32 for ; Mon, 26 Dec 2022 00:30:58 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org BA1A03858D32 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=kernel.crashing.org Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 2BQ0Tvjt026295; Sun, 25 Dec 2022 18:29:57 -0600 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 2BQ0TuIc026294; Sun, 25 Dec 2022 18:29:56 -0600 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Sun, 25 Dec 2022 18:29:55 -0600 From: Segher Boessenkool To: "Jose E. Marchesi" Cc: Richard Biener , Alexander Monakov , Qing Zhao , gcc-patches@gcc.gnu.org Subject: Re: [PATCH V2] Disable sched1 in functions that call setjmp Message-ID: <20221226002955.GD25951@gate.crashing.org> References: <0ad07be0-876d-cc24-6cdb-6b94690dfc52@ispras.ru> <64AC0724-25B0-4A85-AA9E-8A53A82C8A6B@gmail.com> <87edsp86ni.fsf@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87edsp86ni.fsf@oracle.com> User-Agent: Mutt/1.4.2.3i X-Spam-Status: No, score=-3.0 required=5.0 tests=BAYES_00,JMQ_SPF_NEUTRAL,KAM_DMARC_STATUS,SPF_HELO_PASS,SPF_PASS,TXREP autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Hi! On Sat, Dec 24, 2022 at 10:58:41AM +0100, Jose E. Marchesi via Gcc-patches wrote: > Allright, so we have two short-term alternatives for at least remove the > possibility that GCC generates wrong code for valid C when the scheduler > is turned on: > > a) To disable sched1 in functions that call setjmp. That is a heavy hammer. > b) To change deps_analyze_insn so instructions are not moved across > function calls before register allocation (!reload_completed). And this is way heavier still. OTOH, it is possible b) actually improves code (improves performance) in general (and maybe even without such a reload_completed check). > Both patches fix our particular use cases and are regression free in > aarch64-linux-gnu. Did you also check for performance regressions? Segher