From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15800 invoked by alias); 10 Aug 2014 15:02:48 -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 15727 invoked by uid 89); 10 Aug 2014 15:02:48 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.4 required=5.0 tests=AWL,BAYES_40,RP_MATCHES_RCVD,SPF_PASS autolearn=ham version=3.3.2 X-HELO: MXA.qnx.com Received: from mxa.qnx.com (HELO MXA.qnx.com) (72.1.200.108) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-SHA encrypted) ESMTPS; Sun, 10 Aug 2014 15:02:45 +0000 X-ASG-Debug-ID: 1407682962-072188108c20fd50001-6usId6 Received: from exhts.ott.qnx.com (exch2.ott.qnx.com [10.222.2.136]) by MXA.qnx.com with ESMTP id dWESq4XEDnvVWUHA (version=TLSv1 cipher=AES128-SHA bits=128 verify=NO) for ; Sun, 10 Aug 2014 11:02:42 -0400 (EDT) X-Barracuda-Envelope-From: RMansfield@qnx.com Received: from [10.222.100.35] (10.222.2.5) by EXCH2.ott.qnx.com (10.222.2.136) with Microsoft SMTP Server (TLS) id 14.3.174.1; Sun, 10 Aug 2014 11:02:42 -0400 Message-ID: <53E78992.2040303@qnx.com> Date: Sun, 10 Aug 2014 15:02:00 -0000 From: Ryan Mansfield User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Subject: Re: -mno-bmi doesn't work in GCC4.8.2 References: <1407642408642-1059079.post@n5.nabble.com> X-ASG-Orig-Subj: Re: -mno-bmi doesn't work in GCC4.8.2 In-Reply-To: <1407642408642-1059079.post@n5.nabble.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Barracuda-Connect: exch2.ott.qnx.com[10.222.2.136] X-Barracuda-Start-Time: 1407682962 X-Barracuda-Encrypted: AES128-SHA X-Barracuda-URL: http://qnx-spam.ott.qnx.com:80/cgi-mod/mark.cgi X-Barracuda-BRTS-Status: 1 X-Barracuda-Spam-Score: 0.00 X-Barracuda-Spam-Status: No, SCORE=0.00 using global scores of TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=1000.0 tests= X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.3.8295 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- X-IsSubscribed: yes X-SW-Source: 2014-08/txt/msg00080.txt.bz2 On 14-08-09 11:46 PM, hanhwi wrote: > Hi, all, > > I'm using GCC 4.8.2 on x86-64 machine. The compiler emits tzcnt instruction > unlike previous gcc. I want to prevent using tzcnt instruction. As I know, > tzcnt instruction is BMI extension. To disable the feature, I set -mno-bmi > but it didn't work. I believe starting with 4.8 gcc unconditionally emits tzcnt, as non-bmi targets will handle it as rep;bsf, and bmi targets will treat it as a tzcnt. Regards, Ryan Mansfield