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=-8.3 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 F2DBAC47255 for ; Mon, 11 May 2020 18:46:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CE69E20720 for ; Mon, 11 May 2020 18:46:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="PC7MFSA9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729507AbgEKSqW (ORCPT ); Mon, 11 May 2020 14:46:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51362 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727051AbgEKSqV (ORCPT ); Mon, 11 May 2020 14:46:21 -0400 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58625C061A0C for ; Mon, 11 May 2020 11:46:21 -0700 (PDT) Received: by mail-pg1-x542.google.com with SMTP id d22so4965208pgk.3 for ; Mon, 11 May 2020 11:46:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Nscz4Wn57pBdv+UExt3Kccfb3G9SWzhNWKswuT0pTxo=; b=PC7MFSA9Clm1ql2lHJvnPaqCuYo0vwUVioU0XS8aSVEPTNHgcUDEbMmPg7C3yYyDaZ XWcSY8e0QBMUQXEI/PGSwjOiAyTsS22LQNgNZhu5GTOhtzZSD8BQYyNqWY9od199uJrf aFLYX0/g6Usyg0AXdJbnzIUij61esljtU95yMYo8L5xkVDddkHTnwb21VH28IElQOXji NT+6CJktLe8KvM+ZtRAlj08VXEY1AjeLDIR2nNkK1Ze7MDfHUqNJPppK7zB+xJCGgYvz Pa9jUNxCTKVIQhJJ9caZANX8I3IAVhBsWb4LL9O7x50SPpyO1PnXTr4G+BN0A0KyU36a 2+oQ== 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=Nscz4Wn57pBdv+UExt3Kccfb3G9SWzhNWKswuT0pTxo=; b=qab4XkHYMzc+PK1XlCjY3JKhayWCkgDERBxEWKEG8srEMvw8f1Fmtm3I4maeBbf6kg 64yqYD4UZ+N+xcdZBJVRR/OVAjji89lOBxLjAbIS1cbVJ5NbTGU8Nhadf7K8X4KME1Ha 8P67ND6maIpIEaej3Nns+pvOxft4zgIYWCD4B4+6hJZDrFMfBZ7LLzVSOcPC4wgZSeFM LBCs3p29+G8jAvwcXSXGi242G5wybE0C7pEqJeFhXCRB5aoPve7aqsMG1EKMUwsenOJ9 kFGcbYmcYG1kwPrFIuvq8rg09wEayFWmBpnkxBDSOXaIDLlFdj7Aw7rDJYeylyax2dzy SAXw== X-Gm-Message-State: AGi0PuaGnfassxnKQsH/v5uavxBmaq0n2YVBF38mEL8kz1E20l9/t9SL GO8zYoH99+4s3iU6Z/vRpyhTvG8w0wHo+WLmbmOgsg== X-Google-Smtp-Source: APiQypJ19Li3TupJSjOfbTLakXv2IUNQ/VafiApmxJsvFFNNWgK/ozXlHqF8kl8Q/xk9RdoSwgJ1Ut0VgAZReOzBtOA= X-Received: by 2002:a65:5b84:: with SMTP id i4mr16509069pgr.263.1589222780548; Mon, 11 May 2020 11:46:20 -0700 (PDT) MIME-Version: 1.0 References: <20200504230309.237398-1-ndesaulniers@google.com> In-Reply-To: From: Nick Desaulniers Date: Mon, 11 May 2020 11:46:09 -0700 Message-ID: Subject: Re: [PATCH] x86: support i386 with Clang To: Brian Gerst Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , David Woodhouse , Arnd Bergmann , Linus Torvalds , Dmitry Golovin , Dennis Zhou , Tejun Heo , Christoph Lameter , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , "H. Peter Anvin" , Al Viro , Josh Poimboeuf , Masami Hiramatsu , Peter Zijlstra , LKML , clang-built-linux 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 Mon, May 11, 2020 at 11:09 AM Brian Gerst wrote: > This looks like the same issue that we just discussed for bitops.h. > Add the "b" operand size modifier to force it to use the 8-bit > register names (and probably also needs the "w" modifier in the 16-bit > case). While it does feel familiar, it is slightly different. https://godbolt.org/z/Rme4Zg That case was both compilers validating the inline asm, yet generating assembly that the assembler would choke on. This case is validation in the front end failing. Side note: would you mind sending a review by tag for v5 of that patch if you think it's good to go? It does fix a regression I'd prefer didn't ship in 5.7. -- Thanks, ~Nick Desaulniers