From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1Rc2JK-0006YJ-0X for garchives@archives.gentoo.org; Sat, 17 Dec 2011 22:00:54 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id C698A21C23F; Sat, 17 Dec 2011 22:00:30 +0000 (UTC) Received: from smtp.gentoo.org (smtp.gentoo.org [140.211.166.183]) by pigeon.gentoo.org (Postfix) with ESMTP id 0665421C15F for ; Sat, 17 Dec 2011 21:58:43 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp.gentoo.org (Postfix) with ESMTP id 8ACE21B4001 for ; Sat, 17 Dec 2011 21:58:43 +0000 (UTC) X-Virus-Scanned: by amavisd-new using ClamAV at gentoo.org X-Spam-Flag: NO X-Spam-Score: -3.794 X-Spam-Level: X-Spam-Status: No, score=-3.794 tagged_above=-999 required=5.5 tests=[AWL=0.336, BAYES_00=-1.9, FREEMAIL_FROM=0.001, RP_MATCHES_RCVD=-2.229, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=ham Received: from smtp.gentoo.org ([127.0.0.1]) by localhost (smtp.gentoo.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id COpBg524YG8a for ; Sat, 17 Dec 2011 21:58:36 +0000 (UTC) Received: from lo.gmane.org (lo.gmane.org [80.91.229.12]) by smtp.gentoo.org (Postfix) with ESMTP id 7A3771B4008 for ; Sat, 17 Dec 2011 21:58:36 +0000 (UTC) Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1Rc2H2-0004ss-Jl for gentoo-user@gentoo.org; Sat, 17 Dec 2011 22:58:32 +0100 Received: from athedsl-388898.home.otenet.gr ([79.131.71.32]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 17 Dec 2011 22:58:32 +0100 Received: from realnc by athedsl-388898.home.otenet.gr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 17 Dec 2011 22:58:32 +0100 X-Injected-Via-Gmane: http://gmane.org/ To: gentoo-user@lists.gentoo.org From: Nikos Chantziaras Subject: [gentoo-user] Re: -march=native is *EXTREMELY* conservative Date: Sat, 17 Dec 2011 23:58:36 +0200 Organization: Lucas Barks Message-ID: References: <20111217210709.GA1740@waltdnes.org> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@dough.gmane.org X-Gmane-NNTP-Posting-Host: athedsl-388898.home.otenet.gr User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:8.0) Gecko/20111117 Thunderbird/8.0 In-Reply-To: <20111217210709.GA1740@waltdnes.org> X-Archives-Salt: 34d80927-39b1-4dd3-8041-34a44fb7677e X-Archives-Hash: 52449c215a8435e7dd267015bf05c237 On 12/17/2011 11:07 PM, Walter Dnes wrote: > > Then I ran "gcc -march=native -Q --help=target" and got a major shock. > It's a long output listing of what -march=native thinks about my cpu. > Here are some relevant items... > > -march= core2 > -mmmx [disabled] > -msse [disabled] > -msse2 [disabled] > -msse3 [disabled] > -mssse3 [disabled] > > It properly identified the cpu as "core2". But mmx, sse, sse2, sse3 > (aka pni), and ssse3 are disabled!!! The output lies. It's a known issue. Use this instead: echo | gcc -dM -E - -march=native You should see stuff like: #define __MMX__ 1 #define __SSE3__ 1