Received: by 2002:a25:c593:0:0:0:0:0 with SMTP id v141csp1514058ybe; Fri, 6 Sep 2019 20:16:00 -0700 (PDT) X-Google-Smtp-Source: APXvYqwP6nVWPiZ/PDhCnaf/w1ePlvFE5XGhjzY6+zDxd+7ICDAxInkOrd3Mr5DkIHk+Dipd1F1y X-Received: by 2002:a63:3387:: with SMTP id z129mr10625727pgz.177.1567826160138; Fri, 06 Sep 2019 20:16:00 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1567826160; cv=none; d=google.com; s=arc-20160816; b=d6rxQCT0cVWzDUKhK0OE4CImYiIohJDqa5lD5fKEjd4zEM8yItiNP5Uclf4g3A+DRz PjbpM1Bdb57W8r979glzyrEBDTMNmEzafii51olI76hwQna9ett3G/oYGa0/cihXhSVJ gL2mt9VoUI4p203IxCt0QVNjMd6ecWFGqEUcT8HZrisceCsf09BHg9qblc9ihqrPPjIw nqCt6kJhQvyOGqLvKM23odDKDuphJZj+31LyZXr2RSUJzbUVYhiA3H6IXKR2HNcNto8T ib+/L3aHsxmGx/uiDiZtjK1k0j7BPrMJ9PwsUNWSYIwwKwouktspizkkoOhwvRfqV/Jy 5dDg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:dkim-signature; bh=N+hd4ikAg0UpVVUG6qz74A3chZejVQifX4eNqPKApKc=; b=tGeDiigrl62Xz3ugET0yLFqv17Q3848sPR/5+M2Prg0nrKsufyRq1rBKcZ+PUQDeCa SOn/hxY3vTt9Ld/L9MY53Mkkgk2oIQyTNoN9L92smF+sCPLf0Li8Av6EQYsvUZ9vaeyU MFf3vB6g9tVdEbbHDkmlUP5A0dJrmxOoAUGPKCT/0KMxr65mIE/Y+cgrwrgcuaLFDiEZ rldCZ8bbvXsNHJ79rXZVDGcg/K7gW06sqIrnOtEtuUf8DRZK2B+Nzk5RvcK6S2GszNtF DPtkJOtk8MRm5XWYuZnU5QehN1AdGs0KCQoItv/ZmdrDSUwG3AZ64q+i0Va+R0cxk3vT Gsog== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=aGysDeQk; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id g2si6464137plt.26.2019.09.06.20.15.43; Fri, 06 Sep 2019 20:16:00 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=aGysDeQk; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388510AbfIFPOH (ORCPT + 99 others); Fri, 6 Sep 2019 11:14:07 -0400 Received: from mail-lf1-f68.google.com ([209.85.167.68]:40540 "EHLO mail-lf1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729088AbfIFPOH (ORCPT ); Fri, 6 Sep 2019 11:14:07 -0400 Received: by mail-lf1-f68.google.com with SMTP id u29so5339740lfk.7 for ; Fri, 06 Sep 2019 08:14:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=N+hd4ikAg0UpVVUG6qz74A3chZejVQifX4eNqPKApKc=; b=aGysDeQkqqUsNV8borziuung6bBqJ0Mo1pKcZHsg1ADcDuLf/EPmdB3gVcOdlmro8+ Mh1H6+T+aYc9JvScsE/vioBmdPyoN9PXS3mUkWQIGddKEpMti2iFp+yndaqboM4hYA8k TrJbP6yz9lHlah3hRm8Q5j3yUQV7Afu1O0UHQ4jl6/3lYNrImddnELOHoetKtPK+Nd7u r07Wc9izwlOecsxRaHzmu/29cas/6kqp5peyHHvtK2hajmPCw5qmjWVDr7WUSzWvA8yL 1ziR0vTTSEIcMWoYDOi5FOGfY06V/77neH0pWZwGL2AcyVXMuPLWFG+vWSv3jgFWfn/6 //2Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=N+hd4ikAg0UpVVUG6qz74A3chZejVQifX4eNqPKApKc=; b=D3fKgNo5T6818ar5yfKTBpTYQP002kFqXgIHR9RTVrzF2RUT0kPaju0muhVjYS0Gss tPiIy6geN6YS8o0XW4sVT78ff7yazLCxpPxy+QG9SKX0mHZcVH1IJ9JQ15Ec0NDzjWdP 6u3uFImn0ajG2sQAgBVgafcRX/43yWe72hMF8bwg7DCAY40LdWByCDS1QrVbk0ne4ZJv Jdz0UCjpOSH/IeU0NqXjB1YVCHYU2VeH5mgea/Imn3ZR1bJZYv9mNGrHTqiGYNtDFDie FbWnozSAW0CRwzevdC1GvbEj9ioln1lVWT04uVrHaDHQ397jHhz8hlw5OshR30GHuuo6 6ukQ== X-Gm-Message-State: APjAAAXw4yMcW57la+FKDzrPOwuCrAV5UHMWCn8DiL4FT5y6Ft/ZvsCr PPnGxKlULKwZ7X78z7mq5e37mk3BYb5A+DbgEfc= X-Received: by 2002:ac2:568c:: with SMTP id 12mr6580937lfr.133.1567782845460; Fri, 06 Sep 2019 08:14:05 -0700 (PDT) MIME-Version: 1.0 References: <20190829083233.24162-1-linux@rasmusvillemoes.dk> <20190830231527.22304-1-linux@rasmusvillemoes.dk> <20190830231527.22304-5-linux@rasmusvillemoes.dk> <20190905134535.GP9749@gate.crashing.org> <20190906122349.GZ9749@gate.crashing.org> In-Reply-To: <20190906122349.GZ9749@gate.crashing.org> From: Miguel Ojeda Date: Fri, 6 Sep 2019 17:13:54 +0200 Message-ID: Subject: Re: [PATCH v2 4/6] compiler-gcc.h: add asm_inline definition To: Segher Boessenkool Cc: Rasmus Villemoes , Nick Desaulniers , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , LKML , "gcc-patches@gcc.gnu.org" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 6, 2019 at 2:23 PM Segher Boessenkool wrote: > > I can't find anything with "feature" and "macros" in the C++ standard, > it's "predefined macros" there I guess? In C, it is also "predefined > macros" in general, and there is "conditional feature macros". They are introduced in C++20, but they have been added for a lot of older features in both the language (see [cpp.predefined]p1, around 50 of them) and the library (see [support.limits.general]p3, ~100): http://eel.is/c++draft/cpp.predefined#tab:cpp.predefined.ft http://eel.is/c++draft/support.limits#tab:support.ft > Sure. But the name is traditional, many decades old, it predates glibc. > Using an established name to mean pretty much the opposite of what it > normally does is a bit confusing, never mind if that usage makes much > sense ;-) Agreed on principle :-) However, I wouldn't say it is the opposite. I would say they are the same, but from different perspectives: one says "I want to test if the user enabled the feature", the other says "I want to test if the vendor implemented the feature". Which is fine, but for users the meaning is inverted as you say: in the first case they want to say "I want to enable this feature in this library" -- they don't want to "test" anything. And since most people will be users, not vendors writing standard libraries, I think the user perspective would have been better. Cheers, Miguel