From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 101039 invoked by alias); 17 Apr 2019 02:20:44 -0000 Mailing-List: contact gcc-help-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-help-owner@gcc.gnu.org Received: (qmail 101030 invoked by uid 89); 17 Apr 2019 02:20:44 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-1.4 required=5.0 tests=BAYES_00,KAM_NUMSUBJECT,SPF_HELO_PASS,SPF_PASS autolearn=no version=3.3.1 spammy=H*R:D*gcc.gnu.org, H*R:D*gnu.org, mancini, aerospace X-HELO: mengyan1223.wang Received: from mengyan1223.wang (HELO mengyan1223.wang) (89.208.246.23) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 17 Apr 2019 02:20:42 +0000 Received: from xry111-laptop (unknown [123.139.84.188]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (Client did not present a certificate) (Authenticated sender: xry111@mengyan1223.wang) by mengyan1223.wang (Postfix) with ESMTPSA id C1DEC66173; Tue, 16 Apr 2019 22:20:38 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mengyan1223.wang; s=mail; t=1555467639; bh=SVqyOa7RVM6SRznflbOhsKNsOV1Yr3mnL0mvZxYVM3U=; h=Subject:From:Reply-To:To:Cc:Date:In-Reply-To:References:From; b=n2vk/56TGckcyF1lbMm+Vz/prcPPCv9A3qk8WpSROawzWAb+eJuZ6X3AE5A4xpbzZ K908z8VAVu/EmvEKCAOH4T2DF+khQT2CkgAOXp539j84dFTO7h09BqNdDuftzYljU/ ee6XZFR2uLGx7G2T38OoqmxJZkN8KHamlfVREY+EYrolJMgVVqzMiuOSUn6Hm/ZfoT dMpDCuaEiof31rKl4qXYjh0nKXSn/BVPXwE8YBiMMOUSMvxLosFG4VE/kdAARjVQPJ J9XtOuxYZmaBs4JpPUlu/BUE4gYVNQsCrfgyd9NhVbYAEqx8s55X6tT02pxNx3gEaC SL1v3oNswk7VQ== Message-ID: Subject: Re: gcc9 snapshot 20190414 is 30x slower than gcc 6.3 From: Xi Ruoyao Reply-To: "gcc-help@gcc.gnu.org" To: Jason Mancini Cc: "gcc-help@gcc.gnu.org" Date: Wed, 17 Apr 2019 02:20:00 -0000 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.32.0 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2019-04/txt/msg00082.txt.bz2 On 2019-04-17 02:09 +0000, Jason Mancini wrote: > > Using gcc 6.3, my C++ source file compiles in 1m2s with -O0. With snapshot > > 20190414 (compiled with --disable-checking > > and -O2 and make install-strip), it takes 31 minutes to compile the same > > file with -O0. Have I overlooked disabling some > > snapshot self-checking code? Are there known configuration mistakes that > > could result in this sort of performance > > degradation? Thanks! It will take a while to go back and try other gcc 6, > > 7, 8, and 9 snapshots to collect points of reference. > > Both are pretty heavy on memory, gcc6 uses 3.7G and gcc9 uses 5.4G for this > > file. There's a lot of templatized headers. > > Latest data points: > gcc-6.3/6.4 take about 43 seconds > gcc-7.2 takes 30 minutes > gcc-8.2 takes 27 minutes > gcc-9.0 takes 31 minutes (snapshot 20190414) > clang 6.0.1/7.01 take about 31 seconds > > This is frustrating, as I'm going to have to capitulate to using clang here > for a very large user base. We've been a gcc > shop for decades. We'll never know why unless you can give a testcase to reproduce this issue. -- Xi Ruoyao School of Aerospace Science and Technology, Xidian University