From patchwork Fri Feb 1 00:37:47 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kim Phillips X-Patchwork-Id: 2076221 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id D86B640106 for ; Fri, 1 Feb 2013 00:43:36 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1U14gE-0004Oz-BF; Fri, 01 Feb 2013 00:40:34 +0000 Received: from ch1ehsobe004.messaging.microsoft.com ([216.32.181.184] helo=ch1outboundpool.messaging.microsoft.com) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1U14gA-0004Oh-Ez for linux-arm-kernel@lists.infradead.org; Fri, 01 Feb 2013 00:40:31 +0000 Received: from mail230-ch1-R.bigfish.com (10.43.68.232) by CH1EHSOBE012.bigfish.com (10.43.70.62) with Microsoft SMTP Server id 14.1.225.23; Fri, 1 Feb 2013 00:40:27 +0000 Received: from mail230-ch1 (localhost [127.0.0.1]) by mail230-ch1-R.bigfish.com (Postfix) with ESMTP id 638C530010B; Fri, 1 Feb 2013 00:40:27 +0000 (UTC) X-Forefront-Antispam-Report: CIP:70.37.183.190; KIP:(null); UIP:(null); IPV:NLI; H:mail.freescale.net; RD:none; EFVD:NLI X-SpamScore: 0 X-BigFish: VS0(zzzz1ee6h1de0h1202h1e76h1d1ah1d2ahzz17326ah8275bh8275dhz2dh2a8h668h839h944hd24he5bhf0ah1220h1288h12a5h12a9h12bdh137ah139eh13b6h1441h1504h1537h162dh1631h1758h1898h18e1h1946h1155h) Received: from mail230-ch1 (localhost.localdomain [127.0.0.1]) by mail230-ch1 (MessageSwitch) id 1359679226365014_26820; Fri, 1 Feb 2013 00:40:26 +0000 (UTC) Received: from CH1EHSMHS032.bigfish.com (snatpool1.int.messaging.microsoft.com [10.43.68.243]) by mail230-ch1.bigfish.com (Postfix) with ESMTP id 55E941D8004B; Fri, 1 Feb 2013 00:40:26 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by CH1EHSMHS032.bigfish.com (10.43.70.32) with Microsoft SMTP Server (TLS) id 14.1.225.23; Fri, 1 Feb 2013 00:40:26 +0000 Received: from az84smr01.freescale.net (10.64.34.197) by 039-SN1MMR1-001.039d.mgd.msft.net (10.84.1.13) with Microsoft SMTP Server (TLS) id 14.2.318.3; Fri, 1 Feb 2013 00:40:25 +0000 Received: from x9.am.freescale.net (x9.am.freescale.net [10.82.120.9]) by az84smr01.freescale.net (8.14.3/8.14.0) with SMTP id r110eLnF009216; Thu, 31 Jan 2013 17:40:21 -0700 Date: Thu, 31 Jan 2013 18:37:47 -0600 From: Kim Phillips To: "Woodhouse, David" Subject: [PATCH v4] arm: use built-in byte swap function Message-ID: <20130131183747.d56289dbd89b165cf12a9d28@freescale.com> In-Reply-To: <1359670248.27468.13.camel@shinybook.infradead.org> References: <20130128193033.8a0b0a871150c99247f05a95@freescale.com> <20130129083522.GA14302@pd.tnic> <1359478014.3529.157.camel@shinybook.infradead.org> <20130129174249.GB25415@pd.tnic> <1359482147.3529.161.camel@shinybook.infradead.org> <20130129181046.GC25415@pd.tnic> <1359541333.3529.186.camel@shinybook.infradead.org> <20130130200900.9d7cf7908caeaef4ecee1d61@freescale.com> <20130131092801.GV23505@n2100.arm.linux.org.uk> <20130131145947.f62474a0600848df86548b96@freescale.com> <1359670248.27468.13.camel@shinybook.infradead.org> Organization: Freescale Semiconductor, Inc. X-Mailer: Sylpheed 3.2.0 (GTK+ 2.24.13; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-OriginatorOrg: freescale.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130131_194030_527716_726CA59F X-CRM114-Status: GOOD ( 16.84 ) X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [216.32.181.184 listed in list.dnswl.org] -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Russell King - ARM Linux , Rusty Russell , "linux-kernel@vger.kernel.org" , Daniel Santos , Borislav Petkov , David Rientjes , Andrew Morton , "linux-arm-kernel@lists.infradead.org" X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From 1490bd8823c05e0dda982524bb70cb6c6427ddf9 Mon Sep 17 00:00:00 2001 From: Kim Phillips Date: Mon, 28 Jan 2013 19:30:33 -0600 Subject: [PATCH] arm: use built-in byte swap function Enable the compiler intrinsic for byte swapping on arch ARM. This allows the compiler to detect and be able to optimize out byte swappings, e.g. in big endian to big endian moves. A ARCH_DEFINES_BUILTIN_BSWAP is added to allow an ARCH to select it when it wants to control HAVE_BUILTIN_BSWAPxx definitions over those in the generic compiler headers. It can be dependent on a combination of byte swapping instruction availability, the instruction set version, and the state of support in different compiler versions. AFAICT, arm gcc got __builtin_bswap{32,64} support in 4.6, and for the 16-bit version in 4.8. This has a tiny benefit on vmlinux text size (gcc 4.6.4): multi_v7_defconfig: text data bss dec hex filename 3135208 188396 203344 3526948 35d124 vmlinux multi_v7_defconfig with builtin_bswap: text data bss dec hex filename 3135112 188396 203344 3526852 35d0c4 vmlinux exynos_defconfig: text data bss dec hex filename 4286605 360564 223172 4870341 4a50c5 vmlinux exynos_defconfig with builtin_bswap: text data bss dec hex filename 4286405 360564 223172 4870141 4a4ffd vmlinux The savings come mostly from device-tree related code, and some from drivers. Signed-off-by: Kim Phillips --- akin to: http://comments.gmane.org/gmane.linux.kernel.cross-arch/16016 based on linux-next-20130128. Depends on commit "compiler-gcc{3,4}.h: Use GCC_VERSION macro" by Daniel Santos , currently in the akpm branch. v4: - undo v2-3's addition of ARCH_DEFINES_BUILTIN_BSWAP per Boris and David - patch is much less intrusive :) v3: - moved out of uapi swab.h into arch/arm/include/asm/swab.h - moved ARCH_DEFINES_BUILTIN_BSWAP help text into commit message - moved GCC_VERSION >= 40800 ifdef into GCC_VERSION >= 40600 block v2: - at91 and lpd270 builds fixed by limiting to ARMv6 and above (i.e., ARM cores that have support for the 'rev' instruction). Otherwise, the compiler emits calls to libgcc's __bswapsi2 on these ARMv4/v5 builds (and arch ARM doesn't link with libgcc). All ARM defconfigs now have the same build status as they did without this patch (some are broken on linux-next). - move ARM check from generic compiler.h to arch ARM's swab.h. - pretty sure it should be limited to __KERNEL__ builds - add new ARCH_DEFINES_BUILTIN_BSWAP (see Kconfig help). - if set, generic compiler header does not set HAVE_BUILTIN_BSWAPxx - not too sure about this having to be a new CONFIG_, but it's hard to find a place for it given linux/compiler.h doesn't include any arch-specific files. - move new selects to end of CONFIG_ARM's Kconfig select list, as is done in David Woodhouse's original patchseries for ppc/x86. arch/arm/include/asm/swab.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/arm/include/asm/swab.h b/arch/arm/include/asm/swab.h index 537fc9b..e56acff 100644 --- a/arch/arm/include/asm/swab.h +++ b/arch/arm/include/asm/swab.h @@ -34,5 +34,13 @@ static inline __attribute_const__ __u32 __arch_swab32(__u32 x) } #define __arch_swab32 __arch_swab32 +#if GCC_VERSION >= 40600 +#define __HAVE_BUILTIN_BSWAP32__ +#define __HAVE_BUILTIN_BSWAP64__ +#if GCC_VERSION >= 40800 +#define __HAVE_BUILTIN_BSWAP16__ +#endif +#endif + #endif #endif