From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 103146 invoked by alias); 5 Feb 2020 11:03:56 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 103128 invoked by uid 89); 5 Feb 2020 11:03:56 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-3.0 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 spammy=H*i:sk:iQ@mail, H*f:sk:iQ@mail, H*MI:sk:iQ@mail X-HELO: us-smtp-delivery-1.mimecast.com Received: from us-smtp-2.mimecast.com (HELO us-smtp-delivery-1.mimecast.com) (205.139.110.61) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 05 Feb 2020 11:03:55 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580900633; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=s4FQdQlDKPoFOZEDDd+UXQQ76am1r4smnGZ9PhpALUk=; b=c056fkwwqoVPOTI8K6pF23xms/70lwVo7j5GI1wKaMS5gUpj8AuBx3ijuI20nc4gnjJlhF AZww+BSCtDCGxHvFXDNi1iPlKSUR3twqQcdzxTpvhEYel0DK0G7yJqvocLlo8BoTlS1G0k QyPcB/+7yvRaWW2oHLQOIi8MVbiSZfc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-106-CQZKS8fEP7CH97C6Z-4iTw-1; Wed, 05 Feb 2020 06:03:47 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7D05F1063BA3; Wed, 5 Feb 2020 11:03:46 +0000 (UTC) Received: from tucnak.zalov.cz (ovpn-116-51.ams2.redhat.com [10.36.116.51]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 076EA87B1B; Wed, 5 Feb 2020 11:03:45 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.15.2/8.15.2) with ESMTP id 015B3h8u020538; Wed, 5 Feb 2020 12:03:43 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.15.2/8.15.2/Submit) id 015B3ghH020537; Wed, 5 Feb 2020 12:03:42 +0100 Date: Wed, 05 Feb 2020 11:03:00 -0000 From: Jakub Jelinek To: Uros Bizjak Cc: Richard Sandiford , "gcc-patches@gcc.gnu.org" Subject: Re: [PATCH] i386: Omit clobbers from vzeroupper until final [PR92190] Message-ID: <20200205110342.GB17695@tucnak> Reply-To: Jakub Jelinek References: <20200204110521.GO17695@tucnak> <20200204123040.GQ17695@tucnak> <20200204131257.GR17695@tucnak> <20200205095804.GW17695@tucnak> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/1.11.3 (2019-02-01) X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-IsSubscribed: yes X-SW-Source: 2020-02/txt/msg00253.txt.bz2 On Wed, Feb 05, 2020 at 11:46:51AM +0100, Uros Bizjak wrote: > I think we should just enable split4 also for -O0. This would also > allow us to remove the "optimize > 0" check above and allow us to > generate a bit more optimal code even with -O0 for > TARGET_SSE_PARTIAL_REG_DEPENDENCY and TARGET_AVOID_FALSE_DEP_FOR_BMI. The -O0 passes are: test.c.284r.ira test.c.285r.reload # placement of split2 test.c.292r.pro_and_epilogue test.c.295r.jump2 # placement of split4 # placement of split3 test.c.307r.stack test.c.308r.alignments test.c.310r.mach test.c.311r.barriers # placement of split5 test.c.316r.shorten test.c.317r.nothrow test.c.318r.dwarf2 test.c.319r.final It really doesn't matter if for -O0 STACK_REGS we enable split4 or split3, it is the same location, just split3 is better named (split before reg-stack, which is run even at -O0, rather than split before sched2, which is not run at -O0). I think the primary question is, do we for -O0 need to enable split2 (as in, will anything in pro_and_epilogue or jump2 passes benefit from the splitting and worth running two -O0 post-RA split passes), then we could go with the first patch I've posted, or nothing benefits from it in the two passes and it is ok to split only before stack, in that case we can go with the third patch. Jakub