From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753465AbaEHIDb (ORCPT ); Thu, 8 May 2014 04:03:31 -0400 Received: from mailout1.w1.samsung.com ([210.118.77.11]:19320 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752732AbaEHID2 (ORCPT ); Thu, 8 May 2014 04:03:28 -0400 X-AuditID: cbfec7f5-b7fae6d000004d6d-bf-536b3a47d4a7 Message-id: <536B3946.9070106@samsung.com> Date: Thu, 08 May 2014 11:59:02 +0400 From: Andrey Ryabinin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-version: 1.0 To: Afzal Mohammed Cc: linux@arm.linux.org.uk, open list , "moderated list:ARM PORT" Subject: Re: [PATCH] arm: memset: zero out upper bytes in r1 References: <1399273875-8403-1-git-send-email-a.ryabinin@samsung.com> <20140507234255.GA2050@afzal-ThinkPad-R50e> In-reply-to: <20140507234255.GA2050@afzal-ThinkPad-R50e> Content-type: text/plain; charset=ISO-8859-1 Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrBLMWRmVeSWpSXmKPExsVy+t/xa7ruVtnBBnc2y1j837ia3WLT42us Fpd3zWGzuH2Z14HFo6W5h81j56y77B6bl9R7fN4kF8ASxWWTkpqTWZZapG+XwJXRPnsvU8FJ 1orXS06zNTAuZeli5OSQEDCRWHLiIROELSZx4d56ti5GLg4hgaWMEmvW32GCcBqZJDpb97CB VPEKaEnMWXSFGcRmEVCVOLV+BtgkNgE9iX+ztoPViApESNxrPMwKUS8o8WPyPbAaEQEdidsv d4P1Mgt0MEq0b6oGsYUFbCRWrHgNVi8kUCyxf+pbMJtTwELi9rYORoh6HYn9rdPYIGx5ic1r 3jJPYBSYhWTFLCRls5CULWBkXsUomlqaXFCclJ5rpFecmFtcmpeul5yfu4kRErpfdzAuPWZ1 iFGAg1GJh3eBTEawEGtiWXFl7iFGCQ5mJRHeOJ7sYCHelMTKqtSi/Pii0pzU4kOMTBycUg2M drL7Gycd05Db6n9DRs1CXIyHV4r50K0WtSJj8U2ZbA0ygRVrmxjq3nw+Mp3Xbv296ybi0Qy8 WyZYsne7cNj4RLwLWz+prGFbZQQjO7eo6tSof6sKbcSE11yLLtqoGfSZYTlr5SMp74U6exjD Clx29yklae3+xbW49ffpwsN1Hydbfn/qyq3EUpyRaKjFXFScCADOXnc2OwIAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/08/14 03:42, Afzal Mohammed wrote: > > int is to be converted to unsigned char in memset, would having above > change immediately upon entry to memset rather than at a place where it > won't always execute make intention clearer ? (although it doesn't make > difference) > I think it's better to keep it near other manipulations with r1. Plus this will save us from executing extra instruction on 'memset -> 6 -> 5 -> return' path (memset for size <= 3). > ubfx r1, r1, #0, #8 would have given the needed typecasting, but seems > it is available only on ARMv6T2 & above. > Indeed. It might be wrapped it with #if #else, but it will be a bit ugly, probably not worth to do.