From owner-svn-src-all@FreeBSD.ORG Fri Mar 19 16:22:56 2010 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 978DF106566C; Fri, 19 Mar 2010 16:22:56 +0000 (UTC) (envelope-from netch@segfault.kiev.ua) Received: from segfault.kiev.ua (segfault.kiev.ua [193.193.193.4]) by mx1.freebsd.org (Postfix) with ESMTP id 16D508FC0C; Fri, 19 Mar 2010 16:22:55 +0000 (UTC) Received: from segfault.kiev.ua (localhost.segfault.kiev.ua [127.0.0.1]) by segfault.kiev.ua (8.14.3/8.14.3/8.Who.Cares) with ESMTP id o2JGMs37048145; Fri, 19 Mar 2010 18:22:54 +0200 (EET) (envelope-from netch@segfault.kiev.ua) Received: (from netch@localhost) by segfault.kiev.ua (8.14.3/8.14.3/Submit) id o2JGMnRu048142; Fri, 19 Mar 2010 18:22:49 +0200 (EET) (envelope-from netch) Date: Fri, 19 Mar 2010 18:22:49 +0200 From: Valentin Nechayev To: Ivan Voras Message-ID: <20100319162249.GD67820@netch.kiev.ua> References: <7d6fde3d1003182333m336d52fbh987035a21568250d@mail.gmail.com> <9bbcef731003190913k4f3afbd8mb4e767c40433be8e@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9bbcef731003190913k4f3afbd8mb4e767c40433be8e@mail.gmail.com> X-42: On Cc: svn-src-head@freebsd.org, Garrett Cooper , svn-src-all@freebsd.org, src-committers@freebsd.org, Xin LI Subject: Re: I486_CPU and I586_CPU removed from GENERIC kernel [was Re: svn commit: r205307 - head/sys/i386/conf] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: netch@netch.kiev.ua List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 19 Mar 2010 16:22:56 -0000 Fri, Mar 19, 2010 at 17:13:00, ivoras wrote about "Re: I486_CPU and I586_CPU removed from GENERIC kernel [was Re: svn commit: r205307 - head/sys/i386/conf]": > SSE in the userland you mean? Regardless, I don't think there is now > reason for compiling everything as for i386. E.g. why not add at least > -mtune=generic or even also -march=i686 to default gcc options? > > http://gcc.gnu.org/onlinedocs/gcc/i386-and-x86_002d64-Options.html Having userland compiled with i686 will give the same effect as i686-only kernel: it won't boot on machines which doesn't conform to. If it is supposed to boot on i486 and higher, no more than -march=i486 can be used. OTOH it would be quite popular for most desktops and big servers to orient to fresh hardware, so one can (if having enough resources) to split targets: 1) - for most, which would have e.g. CFLAGS=... -march=pentium3 -mmmx -msse -mfpmath=sse,387 -mtune=generic COPTFLAGS=... -march=pentium3 -mtune=generic 2) for small/embedded/etc. with defaults to i486 and make separate binary distributions for them. OT3H it isn't proven to give real effect except very limited cases (CPU-intensive (mplayer, etc.), graphics-intensive apps (KDE)). Mplayer usually uses differently compiled modules for different CPUs. There are quite few applications which can get real benefit. -netch-