From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Tue, 23 Dec 2008 16:37:08 +0000 (GMT) Received: from localhost.localdomain ([127.0.0.1]:12442 "EHLO mail.linux-mips.net") by ftp.linux-mips.org with ESMTP id S24207429AbYLWQhG (ORCPT ); Tue, 23 Dec 2008 16:37:06 +0000 Received: from fluff.linux-mips.net (localhost.localdomain [127.0.0.1]) by mail.linux-mips.net (8.14.2/8.13.1) with ESMTP id mBNGb48d010297; Tue, 23 Dec 2008 17:37:04 +0100 Received: (from ralf@localhost) by fluff.linux-mips.net (8.14.2/8.14.2/Submit) id mBNGb393010296; Tue, 23 Dec 2008 17:37:03 +0100 Date: Tue, 23 Dec 2008 17:37:03 +0100 From: Ralf Baechle To: Manuel Lauss Cc: Linux-MIPS Subject: Re: [PATCH 2/2] Alchemy: provide cpu feature overrides. Message-ID: <20081223163703.GA9952@linux-mips.org> References: <1229973668-18182-1-git-send-email-mano@roarinelk.homelinux.net> <1229973668-18182-2-git-send-email-mano@roarinelk.homelinux.net> <20081223143909.GD5981@linux-mips.org> <20081223172954.06b301cb@scarran.roarinelk.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081223172954.06b301cb@scarran.roarinelk.net> User-Agent: Mutt/1.5.18 (2008-05-17) Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 21660 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ralf@linux-mips.org Precedence: bulk X-list: linux-mips On Tue, Dec 23, 2008 at 05:29:54PM +0100, Manuel Lauss wrote: > > > Code generated for Alchemy does not use all MIPS32r1 features. Add cpu > > > feature overrides tailored for Alchemy chips and help GCC create better > > > code. As a nice sideeffect the size of the resulting kernel is reduced > > > by a few kilobytes (~200kB for a non-modular db1200 devboard build). > > > > The enormous size difference is probably 99% due to atomic and bitops > > which exist in LL/SC and non-LL/SC versions and without the header gcc > > will expand the inline function each time. That will hurt, also > > performance. Also the big size difference suggests that we may want to > > outline some or all of these functions. > > You are of course correct: > > text data bss dec hex filename > 3890074 124400 436528 4451002 43eaba vmlinux > 3890070 124400 436528 4450998 43eab6 vmlinux+mips32r1 > 3690742 124396 436528 4251666 40e012 vmlinux++llsc > 3666386 124332 436528 4227246 4080ae vmlinux+++all Thanks for the numbers. I'm a little surprised that there are only 4 byte difference between the first two variants? Ralf