From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id 8E1D2139083 for ; Sun, 3 Dec 2017 08:09:03 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 4C582E0F90; Sun, 3 Dec 2017 08:08:56 +0000 (UTC) Received: from pmta11.teksavvy.com (pmta11.teksavvy.com [76.10.157.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id E3D62E0EF4 for ; Sun, 3 Dec 2017 08:08:55 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: =?us-ascii?q?A2EiDAD8ryNa/6Wi+M5bHAEBAQQBAQoBA?= =?us-ascii?q?YM8Zm4niQyGB44BAYIwAZhhHRKFEAQCAoUqRBQBAQEBAQEBAQEDaCiCa0tYAQE?= =?us-ascii?q?BAQEBIwINXgY6HDMLIRMSDwUlN4oiEKloilUBAQgCIQWDQYJegQKFFIMYgXxZg?= =?us-ascii?q?nqCMgWKOYhhj1ICgjmFOY0QjAcah0KMfok/gUo2I4FNfAiCY4RzIzcBAQGHVYJ?= =?us-ascii?q?FAQEB?= X-IPAS-Result: =?us-ascii?q?A2EiDAD8ryNa/6Wi+M5bHAEBAQQBAQoBAYM8Zm4niQyGB44?= =?us-ascii?q?BAYIwAZhhHRKFEAQCAoUqRBQBAQEBAQEBAQEDaCiCa0tYAQEBAQEBIwINXgY6H?= =?us-ascii?q?DMLIRMSDwUlN4oiEKloilUBAQgCIQWDQYJegQKFFIMYgXxZgnqCMgWKOYhhj1I?= =?us-ascii?q?CgjmFOY0QjAcah0KMfok/gUo2I4FNfAiCY4RzIzcBAQGHVYJFAQEB?= X-IronPort-AV: E=Sophos;i="5.45,352,1508817600"; d="scan'208";a="11041111" Received: from 206-248-162-165.dsl.teksavvy.com (HELO waltdnes.org) ([206.248.162.165]) by smtp.teksavvy.com with SMTP; 03 Dec 2017 03:08:53 -0500 Received: by waltdnes.org (sSMTP sendmail emulation); Sun, 03 Dec 2017 03:08:52 -0500 From: "Walter Dnes" Date: Sun, 3 Dec 2017 03:08:52 -0500 To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] CFLAGS for both AMD64 and Intel? Message-ID: <20171203080852.GB30078@waltdnes.org> References: 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=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.7.2 (2016-11-26) X-Archives-Salt: a5cc2499-fd26-4d32-9691-4decfcbbac95 X-Archives-Hash: 9c7d87f2d9ff96d1df71b29efc35ae70 On Sat, Dec 02, 2017 at 11:23:10PM -0800, Manuel McLure wrote > Here's the situation. I have a system that's been running for many years > with an Athlon 5050e processor. The system is built with > > CFLAGS="-march=k8-sse3 -O2 -pipe -msse3" > CPU_FLAGS_X86="3dnow 3dnowext mmx mmxext sse sse2 sse3" > > I have the possibility of upgrading the system to a first-generation > Intel Core i5 which should give a nice speed boost, but of course the > Intel chip doesn't understand 3dnow or 3dnowext, so I'll have to do > a system rebuild before I switch out the motherboard/processor. It > seems pretty obvious that I have to take "3dnow 3dnowext" out of > CPU_FLAGS_X86, but what CFLAGS would be recommended for a system > that will still run with the AMD processor but won't fall over when > I switch to the Intel processor? Once I have the Intel in place I > can rebuild with options more suited for that chip, but I want to > make sure I don't end up in a catch-22 situation. https://gcc.gnu.org/onlinedocs/gcc-6.4.0/gcc/x86-Options.html#x86-Options lists what instruction sets gcc expects for any "-march=" I would suggest rebuilding with... CFLAGS="-march=nocona -O2 -pipe" CPU_FLAGS_X86="mmx sse sse2 sse3" nocona was the first Intel cpu to support AMD64 instructions, and it's the newest Intel that does not exceed your AMD. The next Intel cpu, the "core2" supports ssse3 which your AMD does not (count the "s"'s... very carefully; sse3 != ssse3). -- Walter Dnes I don't run "desktop environments"; I run useful applications