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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 A8E35C43441 for ; Wed, 21 Nov 2018 13:49:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 77BA9214C4 for ; Wed, 21 Nov 2018 13:49:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 77BA9214C4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ACULAB.COM Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730577AbeKVAXy convert rfc822-to-8bit (ORCPT ); Wed, 21 Nov 2018 19:23:54 -0500 Received: from eu-smtp-delivery-151.mimecast.com ([146.101.78.151]:25535 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726862AbeKVAXy (ORCPT ); Wed, 21 Nov 2018 19:23:54 -0500 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-87-NcnHDzCeO-iSMuTSmx2pOw-1; Wed, 21 Nov 2018 13:49:19 +0000 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b::d117) by AcuMS.aculab.com (fd9f:af1c:a25b::d117) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Wed, 21 Nov 2018 13:49:26 +0000 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; Wed, 21 Nov 2018 13:49:26 +0000 From: David Laight To: 'Jan Beulich' CC: "mingo@elte.hu" , "tglx@linutronix.de" , Boris Ostrovsky , "Juergen Gross" , "linux-kernel@vger.kernel.org" , "hpa@zytor.com" Subject: RE: [PATCH v2] x86: modernize sync_bitops.h Thread-Topic: [PATCH v2] x86: modernize sync_bitops.h Thread-Index: AQHUgYKYAz8XcFA8pkaOqgSV6G3YUKVaHKgQgAAVTACAAAwV0A== Date: Wed, 21 Nov 2018 13:49:26 +0000 Message-ID: <47f7dfd9b32f4425ac8466c8b0065c6e@AcuMS.aculab.com> References: <5B30C2C302000078001CD6D1@prv1-mh.provo.novell.com> <5B30C2C302000000000FA99B@prv1-mh.provo.novell.com> <5B30C2C302000078001FE5A0@prv1-mh.provo.novell.com> <5BF52F4D02000078001FE5C1@prv1-mh.provo.novell.com> <92f590595593498eaa1f91a17875126f@AcuMS.aculab.com> <5BF5577202000078001FE7AC@prv1-mh.provo.novell.com> In-Reply-To: <5BF5577202000078001FE7AC@prv1-mh.provo.novell.com> Accept-Language: en-GB, en-US Content-Language: 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 X-MC-Unique: NcnHDzCeO-iSMuTSmx2pOw-1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jan Beulich > Sent: 21 November 2018 13:03 > > >>> On 21.11.18 at 12:55, wrote: > > From: Jan Beulich > >> Sent: 21 November 2018 10:11 > >> > >> Add missing insn suffixes and use rmwcc.h just like was (more or less) > >> recently done for bitops.h as well. > > > > Why? bts (etc) on memory don't really have an 'operand size'. > > Of course they do - depending on operand size they operate on > 2-, 4-, or 8-byte quantities. When the second operand is a > register, the suffix is redundant (but doesn't hurt), but when > the second operand is an immediate, the assembler (in AT&T > syntax) has no way of knowing what operand size you mean. You need to RTFM. Regardless of the 'operand size' the 'bit' instructions do a 32 bit aligned 32 bit wide read/modify/write cycle. The 'operand size' does affect whether the bit number (which is signed) comes from %cl (8 bits), %cx (16 bits), %rcx (32 bits) or (%ecx) 64 bits. But that is implicit in the register name used. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)