From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 5B8ECB6FAC for ; Thu, 7 Jun 2012 16:39:45 +1000 (EST) Message-ID: <1339051173.24838.10.camel@pasglop> Subject: Re: [PATCH] powerpc: Optimise the 64bit optimised __clear_user From: Benjamin Herrenschmidt To: Michael Neuling Date: Thu, 07 Jun 2012 16:39:33 +1000 In-Reply-To: <4725.1339049104@neuling.org> References: <20120604175858.38dac554@kryten> <20120605120222.6722a3e3@kryten> <178E3BC0-C6E2-4E33-BA66-8144F192A151@kernel.crashing.org> <1339017602.7150.174.camel@pasglop> <4725.1339049104@neuling.org> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Cc: michael@ellerman.id.au, paulus@samba.org, Anton Blanchard , olof@lixom.net, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2012-06-07 at 16:05 +1000, Michael Neuling wrote: > One problem with this is when we construct the instructions, like using > anything from ppc-opcode.h. eg. using PPC_POPCNTB would need to go from: > PPC_POPCNTB(r3,r3) > to: > PPC_POPCNTB(3,3) > Which is less readable IMHO. Yes, I know. Not much to do about this, but it might still be worth it, how much time wasted due to mixing up or with ori in asm somewhere ? One option would be to #define R3 (or _r3) for use in those macros so we still have something nicer than just "3"... oh well. Cheers, Ben.