Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752166AbbEDUpN (ORCPT ); Mon, 4 May 2015 16:45:13 -0400 Received: from mail-ie0-f182.google.com ([209.85.223.182]:33862 "EHLO mail-ie0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751115AbbEDUpH (ORCPT ); Mon, 4 May 2015 16:45:07 -0400 MIME-Version: 1.0 In-Reply-To: <5547D7A3.2010203@redhat.com> References: <20150501151630.GH5029@twins.programming.kicks-ass.net> <20150501163329.GU1751@tucnak.redhat.com> <5543CDC0.6010206@redhat.com> <20150502123958.GK5029@twins.programming.kicks-ass.net> <5547C992.9000703@redhat.com> <5547D30B.2020507@zytor.com> <5547D7A3.2010203@redhat.com> Date: Mon, 4 May 2015 13:45:06 -0700 X-Google-Sender-Auth: DCPIAyOonIHS13I-JZ4Va6NbmKA Message-ID: Subject: Re: [RFC] Design for flag bit outputs from asms From: Linus Torvalds To: Richard Henderson Cc: "H. Peter Anvin" , Peter Zijlstra , Vladimir Makarov , Jakub Jelinek , Ingo Molnar , Thomas Gleixner , Linux Kernel Mailing List , Borislav Petkov , "gcc@gcc.gnu.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 843 Lines: 18 On Mon, May 4, 2015 at 1:33 PM, Richard Henderson wrote: > > A fair point. Though honestly, I was hoping that this feature would mostly be > used for conditions that are "weird" -- that is, not normally describable by > arithmetic at all. Otherwise, why are you using inline asm for it? I could easily imagine using some of the combinations for atomic operations. For example, doing a "lock decl", and wanting to see if the result is negative or zero. Sure, it would be possible to set *two* booleans (ZF and SF), but there's a contiional for "BE".. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/