From owner-freebsd-questions@FreeBSD.ORG Sun Feb 28 14:40:15 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 611A31065680 for ; Sun, 28 Feb 2010 14:40:15 +0000 (UTC) (envelope-from onemda@gmail.com) Received: from mail-ew0-f226.google.com (mail-ew0-f226.google.com [209.85.219.226]) by mx1.freebsd.org (Postfix) with ESMTP id EBB328FC1E for ; Sun, 28 Feb 2010 14:40:14 +0000 (UTC) Received: by ewy26 with SMTP id 26so849522ewy.3 for ; Sun, 28 Feb 2010 06:40:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type; bh=n5qSXfOdyWux0u+ygy0I9zC/JJvhO2t35cGq54bi0as=; b=cbM62MvHtA4nkFfDVKtyC4Jsxi0YyWRTE2rywJ6WqZkVdAUNUDEOFSF5MGWxYkcmyh p1yoJ4O0chiK+1Tb1vd7mmzdHRDgw5BZnMEou4UqqmuAjIZ3pNdscCpcUdW3Ys0JlfW7 Uf6rWINdc5wuigIQWwhTu+xZcV9yXqf1oMqEs= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=kqYTNib30wb4uCwwK6O3tC4x3tAOgbWXnB/k1sNldCZunMvxul0fKet33zr6lkQEp4 3KINrDSgeZdd/dldiv8WRWYQKR0HXqBdtDdCyMpDEDm1ZcHbQNWkq/1EoKaQQvior5Ot QAA2E+62r0KQNruXNyACuSpQtUIhg1dkcYlnU= MIME-Version: 1.0 Received: by 10.213.111.18 with SMTP id q18mr2015729ebp.39.1267367998814; Sun, 28 Feb 2010 06:39:58 -0800 (PST) In-Reply-To: <4B8A7FA7.1070200@gmail.com> References: <4B8A63D5.90104@gmail.com> <3a142e751002280624w6f38d297o65b88301b3e5f8d@mail.gmail.com> <4B8A7FA7.1070200@gmail.com> Date: Sun, 28 Feb 2010 14:39:58 +0000 Message-ID: <3a142e751002280639rdb25d3ajd688caecfedfacbb@mail.gmail.com> From: Paul B Mahol To: Aaron Lewis Content-Type: text/plain; charset=ISO-8859-1 Cc: freebsd-questions@freebsd.org Subject: Re: Compiler Flags problem with core2 CPU X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 28 Feb 2010 14:40:15 -0000 Do not top post. On 2/28/10, Aaron Lewis wrote: > Really ? It's bad to use custom flags to compile kernel , why do you > think so ? > I'd like to know more about this : ) Use google. > > So setting optimize compiler flags is only useful for userland stuff ? > > Paul B Mahol wrote: >> On 2/28/10, Aaron Lewis wrote: >> >>> Hi, >>> I gonna recompile kernel for my core2 CPU , so i'd like to pass some >>> flags to gcc. >>> Kinds of "-march=core2" , i tried to modify /etc/make.conf >>> >>> e.g CFLAGS += -march=core2 -O20 -ffast-math -mfpmath=sse >>> But it fails .. bad arch switch , core2 cpu is not supported ? >>> >> It is bad idea to compile kernel with custom flags. And gcc in FreeBSD >> doesn't know about core2, >> use 'native' if you must. >> >> >>> And is that useful to let gcc select cpu specified asm code ? >>> >> >> Only for some userland stuff like openssl. >> > > > -- > Best Regards, > Aaron Lewis - PGP: 0xA476D2E9 > irc: A4r0n on freenode > >