From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8402 invoked by alias); 3 Oct 2012 16:57:54 -0000 Received: (qmail 8391 invoked by uid 22791); 3 Oct 2012 16:57:53 -0000 X-SWARE-Spam-Status: No, hits=-7.3 required=5.0 tests=AWL,BAYES_00,KHOP_RCVD_UNTRUST,KHOP_SPAMHAUS_DROP,RCVD_IN_DNSWL_HI,RCVD_IN_HOSTKARMA_W,RP_MATCHES_RCVD,SPF_HELO_PASS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 03 Oct 2012 16:57:48 +0000 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q93GvlSS027261 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 3 Oct 2012 12:57:48 -0400 Received: from zalov.redhat.com (vpn1-4-138.ams2.redhat.com [10.36.4.138]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id q93GvktE002412 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 3 Oct 2012 12:57:47 -0400 Received: from zalov.cz (localhost [127.0.0.1]) by zalov.redhat.com (8.14.5/8.14.5) with ESMTP id q93GvjlJ022812; Wed, 3 Oct 2012 18:57:45 +0200 Received: (from jakub@localhost) by zalov.cz (8.14.5/8.14.5/Submit) id q93GvilJ022811; Wed, 3 Oct 2012 18:57:44 +0200 Date: Wed, 03 Oct 2012 16:57:00 -0000 From: Jakub Jelinek To: Lawrence Crowl Cc: Ian Lance Taylor , Richard Guenther , gcc-patches List , Diego Novillo Subject: Re: Convert more non-GTY htab_t to hash_table. Message-ID: <20121003165744.GU1787@tucnak.redhat.com> Reply-To: Jakub Jelinek References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-IsSubscribed: yes 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 X-SW-Source: 2012-10/txt/msg00279.txt.bz2 On Wed, Oct 03, 2012 at 09:54:45AM -0700, Lawrence Crowl wrote: > On 10/2/12, Ian Lance Taylor wrote: > > On Oct 2, 2012 Lawrence Crowl wrote: > > > On 10/2/12, Richard Guenther wrote: > > > > You are changing a hashtable used by fold checking, did you > > > > test with fold checking enabled? > > > > > > I didn't know I had to do anything beyond the normal make check. > > > What do I do? > > > > Fold checking is not enabled by default because of high overhead > > and general pointlessness. To enable it, when you run configure, > > use --enable-checking=yes,fold. > > So, why have the feature if it is pointless? Just curious. It is not pointless, just seldom used. The reason for the verification code is to (very expensively) verify that fold_binary etc. doesn't modify passed expressions in place, instead if it needs to make changes, it allocates new trees. It is not something for every day use (unlike say tree or rtl checking which can be enabled on faster build boxes for daily bootstraps on the trunk), but something to be checked once a year or so (similarly to --enable-checking=valgrind, which is even more expensive). Jakub