From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756814AbXL2JxS (ORCPT ); Sat, 29 Dec 2007 04:53:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753810AbXL2JxI (ORCPT ); Sat, 29 Dec 2007 04:53:08 -0500 Received: from smtp5.pp.htv.fi ([213.243.153.39]:40731 "EHLO smtp5.pp.htv.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753246AbXL2JxH (ORCPT ); Sat, 29 Dec 2007 04:53:07 -0500 Date: Sat, 29 Dec 2007 11:52:53 +0200 From: Adrian Bunk To: Sam Ravnborg Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andi Kleen , LKML Subject: Re: [PATCH] x86: unify x86 Makefile(s) Message-ID: <20071229095253.GC27360@does.not.exist> References: <20071228212341.GA6939@uranus.ravnborg.org> <20071228221324.GA9105@does.not.exist> <20071229093904.GA17390@uranus.ravnborg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20071229093904.GA17390@uranus.ravnborg.org> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Dec 29, 2007 at 10:39:04AM +0100, Sam Ravnborg wrote: > On Sat, Dec 29, 2007 at 12:13:24AM +0200, Adrian Bunk wrote: > > On Fri, Dec 28, 2007 at 10:23:41PM +0100, Sam Ravnborg wrote: > > >... > > > Noteworthy remarks on the unification: > > >... > > > - -funit-at-a-time should be easy to unify but it looks like we have a bug > > > in 32 bit. We only enable -funit-at-a-time for gcc less than 0400 if they > > > support it > > > > No, we _dis_able it on 32bit if a gcc < 4.0 supports it. > I have: > $ gcc --version > gcc (GCC) 4.1.2 20070925 (Red Hat 4.1.2-33) > > And with the current code in arch/x86/Makefile_32 I do not > have -funit-at-a-time. >... You do not have this option, but you do not need it since it's enabled with -O in all gcc versions that support it except for some vendor backports to gcc 3.3. >... > This is the relevant snippet from the Makefile: > KBUILD_CFLAGS += $(shell if [ $(call cc-version) -lt 0400 ] ; then echo $(call cc-option,-fno-unit-at-a-time); fi ;) > > It reads: > If gcc version is less than 4.00 then enable -funit-at-a-time only for gcc that supports it. > -funit-at-a-time is NOT enabled for gcc >= 4.00 It is not _explicitely_ enabled for gcc >= 4.0 since it's anyway enabled. > So it will enable -funit-at-a-time for gcc 3.4 as it is now. > Which was what we wanted to avoid.. > So I see no reason not to enable it uncondintionally (if gcc supports it) as we have > used it for 3.4 for as long as we have introduced -funit-at-a-time. We have never used it with gcc 3.4 on i386. > Sam cu Adrian -- "Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed