From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8876 invoked by alias); 26 Nov 2013 16:26:22 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 8860 invoked by uid 89); 26 Nov 2013 16:26:21 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=1.0 required=5.0 tests=AWL,BAYES_50,RDNS_NONE,SPF_HELO_PASS,SPF_PASS,URIBL_BLOCKED autolearn=no version=3.3.2 X-HELO: mx1.redhat.com Received: from Unknown (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 26 Nov 2013 16:26:20 +0000 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id rAQGQ6WH011983 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 26 Nov 2013 11:26:07 -0500 Received: from stumpy.slc.redhat.com (ovpn-113-65.phx2.redhat.com [10.3.113.65]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id rAQGQ6Mo029157; Tue, 26 Nov 2013 11:26:06 -0500 Message-ID: <5294CB9E.1010306@redhat.com> Date: Tue, 26 Nov 2013 16:26:00 -0000 From: Jeff Law User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Paul Koning , Jan-Benedict Glaw CC: "gcc@gcc.gnu.org Development" Subject: Re: [buildrobot] pdp11-aout References: <20131126032546.GX30563@lug-owl.de> <35F5B26B-B1E5-40E3-A598-F715571B9522@comcast.net> In-Reply-To: <35F5B26B-B1E5-40E3-A598-F715571B9522@comcast.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit X-IsSubscribed: yes X-SW-Source: 2013-11/txt/msg00539.txt.bz2 On 11/26/13 08:55, Paul Koning wrote: > > On Nov 25, 2013, at 10:25 PM, Jan-Benedict Glaw > wrote: > >> Hi! >> >> Build log at >> http://toolchain.lug-owl.de/buildbot/show_build_details.php?id=40865 >> >> >> g++ -c -g -O2 -DIN_GCC -DCROSS_DIRECTORY_STRUCTURE -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wmissing-format-attribute -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -Werror -fno-common -DHAVE_CONFIG_H -I. -I. -I../../../gcc/gcc -I../../../gcc/gcc/. -I../../../gcc/gcc/../include -I../../../gcc/gcc/../libcpp/include -I/opt/cfarm/mpc/include -I../../../gcc/gcc/../libdecnumber -I../../../gcc/gcc/../libdecnumber/dpd -I../libdecnumber -I../../../gcc/gcc/../libbacktrace -o cfgexpand.o -MT cfgexpand.o -MMD -MP -MF ./.deps/cfgexpand.TPo ../../../gcc/gcc/cfgexpand.c >> ../../../gcc/gcc/cfgexpand.c: In function ‘basic_block_def* >> expand_gimple_cond(basic_block, gimple)’: >> ../../../gcc/gcc/cfgexpand.c:2027:65: error: comparison is always >> true due to limited range of data type [-Werror=type-limits] else >> if (BRANCH_COST (optimize_insn_for_speed_p (), false) < 4) ^ >> cc1plus: all warnings being treated as errors make[2]: *** >> [cfgexpand.o] Error 1 > > Interesting. In the pdp11 target, BRANCH_COST is either 0 or 1. So > yes, that comparison is always true. > > Is there a requirement that all targets must have branch cost that > it, at least some of the time, 4 or greater? If so, why? If not, > then I suppose cfgexpand.c could be changed to defeat this message, > but how, or why? In general, it seems perfectly reasonable to have > code guarded by conditions that may be always true, or always false. > That's what we have optimizers for. Defeating such optimizations by > calling them an error seems like a bad idea. No, there's no such requirement on the targets to have a branch cost > 4. Jeff