From: Denys Vlasenko Subject: Re: [camellia-oss:00952] Re: [PATCH 5/5] camellia: de-unrolling, 64bit-ization Date: Tue, 13 Nov 2007 19:47:08 -0700 Message-ID: <200711131947.09040.vda.linux@googlemail.com> References: <20071113.150702.628183529.takamiya@po.ntts.co.jp> <200711131534.33521.vda.linux@googlemail.com> <20071113.174104.224925773.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: takamiya@po.ntts.co.jp, herbert@gondor.apana.org.au, linux-crypto@vger.kernel.org To: David Miller Return-path: Received: from wr-out-0506.google.com ([64.233.184.227]:4792 "EHLO wr-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753758AbXKNCrQ (ORCPT ); Tue, 13 Nov 2007 21:47:16 -0500 Received: by wr-out-0506.google.com with SMTP id 36so31892wra for ; Tue, 13 Nov 2007 18:47:15 -0800 (PST) In-Reply-To: <20071113.174104.224925773.davem@davemloft.net> Content-Disposition: inline Sender: linux-crypto-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On Tuesday 13 November 2007 18:41, David Miller wrote: > From: Denys Vlasenko > Date: Tue, 13 Nov 2007 15:34:33 -0700 > > > My preferred solution is to make loop unrolling conditional on > > CONFIG_CC_OPTIMIZE_FOR_SIZE - and this is what is done in my > > (first) patch (see attached). This part: > > The default build is going to be CONFIG_CC_OPTIMIZE_FOR_SIZE > basically for everyone, this is what people get by default > and this is what every distribution uses. > > Therefore %99.9999 of folks will get the slowdown. > > So in my book this is not an acceptable way to deal with > this problem. Loop unrolling here amounts to 25% code growth: text data bss dec hex filename 21714 0 0 21714 54d2 camellia5.o 15906 0 0 15906 3e22 camellia5_Os.o Saving 25% or code size and going 5% slower is perfectly acceptable tradeof for some users. NB: I'm not saying all, ut some significant part of users would like to be able to have this choice. If CONFIG_CC_OPTIMIZE_FOR_SIZE is not an acceptable method, do you have other ideas? -- vda