From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C69ABC4363A for ; Tue, 20 Oct 2020 21:36:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 63FFD2224A for ; Tue, 20 Oct 2020 21:36:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438722AbgJTVgF convert rfc822-to-8bit (ORCPT ); Tue, 20 Oct 2020 17:36:05 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.86.151]:44439 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2438720AbgJTVgF (ORCPT ); Tue, 20 Oct 2020 17:36:05 -0400 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-157-HDk49QzJPzOC6GM_K5-_uA-1; Tue, 20 Oct 2020 22:36:01 +0100 X-MC-Unique: HDk49QzJPzOC6GM_K5-_uA-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) by AcuMS.aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Tue, 20 Oct 2020 22:36:00 +0100 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Tue, 20 Oct 2020 22:36:00 +0100 From: David Laight To: 'Arvind Sankar' , Herbert Xu , "David S. Miller" , "linux-crypto@vger.kernel.org" CC: "linux-kernel@vger.kernel.org" Subject: RE: [PATCH v2 6/6] crypto: lib/sha - Combine round constants and message schedule Thread-Topic: [PATCH v2 6/6] crypto: lib/sha - Combine round constants and message schedule Thread-Index: AQHWpyE0sF/IXICPKESRSNEpjVVK3amhAtQw Date: Tue, 20 Oct 2020 21:36:00 +0000 Message-ID: References: <20201020203957.3512851-1-nivedita@alum.mit.edu> <20201020203957.3512851-7-nivedita@alum.mit.edu> In-Reply-To: <20201020203957.3512851-7-nivedita@alum.mit.edu> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org From: Arvind Sankar > Sent: 20 October 2020 21:40 > > Putting the round constants and the message schedule arrays together in > one structure saves one register, which can be a significant benefit on > register-constrained architectures. On x86-32 (tested on Broadwell > Xeon), this gives a 10% performance benefit. I'm actually stunned it makes that much difference. The object code must be truly horrid (before and after). There are probably other strange tweaks that give a similar improvement. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)