From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f171.google.com (mail-pd0-f171.google.com [209.85.192.171]) by kanga.kvack.org (Postfix) with ESMTP id 1D01F280018 for ; Thu, 30 Oct 2014 22:03:35 -0400 (EDT) Received: by mail-pd0-f171.google.com with SMTP id r10so6297686pdi.2 for ; Thu, 30 Oct 2014 19:03:34 -0700 (PDT) Received: from cnbjrel01.sonyericsson.com (cnbjrel01.sonyericsson.com. [219.141.167.165]) by mx.google.com with ESMTPS id qk1si7970588pac.189.2014.10.30.19.03.32 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 30 Oct 2014 19:03:34 -0700 (PDT) From: "Wang, Yalin" Date: Fri, 31 Oct 2014 10:03:27 +0800 Subject: RE: [RFC V5 3/3] arm64:add bitrev.h file to support rbit instruction Message-ID: <35FD53F367049845BC99AC72306C23D103E010D1826F@CNBJMBX05.corpusers.net> References: <35FD53F367049845BC99AC72306C23D103E010D18254@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18257@CNBJMBX05.corpusers.net> <1414392371.8884.2.camel@perches.com> <35FD53F367049845BC99AC72306C23D103E010D1825F@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18260@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18261@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18264@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18265@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18266@CNBJMBX05.corpusers.net> <20141030120127.GC32589@arm.com> In-Reply-To: <20141030120127.GC32589@arm.com> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: 'Will Deacon' Cc: 'Rob Herring' , 'Joe Perches' , 'Russell King - ARM Linux' , "'linux-kernel@vger.kernel.org'" , "'akinobu.mita@gmail.com'" , "'linux-mm@kvack.org'" , "'linux-arm-kernel@lists.infradead.org'" > From: Will Deacon [mailto:will.deacon@arm.com] > Sent: Thursday, October 30, 2014 8:01 PM > To: Wang, Yalin > Cc: 'Rob Herring'; 'Joe Perches'; 'Russell King - ARM Linux'; 'linux- > kernel@vger.kernel.org'; 'akinobu.mita@gmail.com'; 'linux-mm@kvack.org'; > 'linux-arm-kernel@lists.infradead.org' > Subject: Re: [RFC V5 3/3] arm64:add bitrev.h file to support rbit > instruction >=20 > > +static __always_inline __attribute_const__ u32 __arch_bitrev32(u32 x) > > +{ > > + if (__builtin_constant_p(x)) { > > + x =3D (x >> 16) | (x << 16); > > + x =3D ((x & 0xFF00FF00) >> 8) | ((x & 0x00FF00FF) << 8); > > + x =3D ((x & 0xF0F0F0F0) >> 4) | ((x & 0x0F0F0F0F) << 4); > > + x =3D ((x & 0xCCCCCCCC) >> 2) | ((x & 0x33333333) << 2); > > + return ((x & 0xAAAAAAAA) >> 1) | ((x & 0x55555555) << 1); >=20 > Shouldn't this part be in the generic code? Good idea, I will change this part into linux/bitrev.h . Thanks -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org