From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756643AbXL2JjS (ORCPT ); Sat, 29 Dec 2007 04:39:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752568AbXL2JjI (ORCPT ); Sat, 29 Dec 2007 04:39:08 -0500 Received: from pasmtpa.tele.dk ([80.160.77.114]:56617 "EHLO pasmtpA.tele.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751713AbXL2JjH (ORCPT ); Sat, 29 Dec 2007 04:39:07 -0500 Date: Sat, 29 Dec 2007 10:39:04 +0100 From: Sam Ravnborg To: Adrian Bunk Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andi Kleen , LKML Subject: Re: [PATCH] x86: unify x86 Makefile(s) Message-ID: <20071229093904.GA17390@uranus.ravnborg.org> References: <20071228212341.GA6939@uranus.ravnborg.org> <20071228221324.GA9105@does.not.exist> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071228221324.GA9105@does.not.exist> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Sample gcc cammandline: gcc -m32 -Wp,-MD,init/.do_mounts_rd.o.d -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/4.1.2/include -D__KERNEL__ -Iinclude -include include/linux/autoconf.h -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -Werror-implicit-function-declaration -Os -pipe -msoft-float -mregparm=3 -freg-struct-return -mpreferred-stack-boundary=2 -march=i686 -mtune=pentium3 -mtune=generic -ffreestanding -maccumulate-outgoing-args -DCONFIG_AS_CFI=1 -DCONFIG_AS_CFI_SIGNAL_FRAME=1 -Iinclude/asm-x86/mach-generic -Iinclude/asm-x86/mach-default -fomit-frame-pointer -fno-stack-protector -Wdeclaration-after-statement -Wno-pointer-sign -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(do_mounts_rd)" -D"KBUILD_MODNAME=KBUILD_STR(mounts)" -c -o init/do_mounts_rd.o init/do_mounts_rd.c 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 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. Sam