From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?B?TWFydGluIExpxaFrYQ==?= Subject: Re: [PATCH 1/2] compiler/gcc5: Remove quirk for asm_volatile_goto() Date: Wed, 15 Apr 2015 11:08:43 +0200 Message-ID: <552E2A9B.7030605@suse.cz> References: <552CDCF0.3050401@suse.cz> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------000902010403090201080709" Return-path: Received: from cantor2.suse.de ([195.135.220.15]:57649 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751506AbbDOJIq (ORCPT ); Wed, 15 Apr 2015 05:08:46 -0400 In-Reply-To: Sender: linux-sparse-owner@vger.kernel.org List-Id: linux-sparse@vger.kernel.org To: Linus Torvalds Cc: Sparse Mailing-list , Chris Li This is a multi-part message in MIME format. --------------000902010403090201080709 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit On 04/14/2015 07:58 PM, Linus Torvalds wrote: > On Tue, Apr 14, 2015 at 2:25 AM, Martin Liška wrote: >> Remove comments related to GCC 4.x branch and workaround for >> asm_volatile_goto which is fixed in GCC 5 release. > > How sure are you that it is *really* fixed? Because it wasn't, last we saw. > > It was originally claimed to be fixed in 4.8.2, but that turned out to > be wrong. See commit 5631b8fba640 ("compiler/gcc4+: Remove inaccurate > comment about 'asm goto' miscompiles"), and > > https://lkml.org/lkml/2014/2/12/817 > > which shows that the bugzilla you reference is at the very least > unreliable. Apparently the gcc test-case didn't catch all the > problems. > > IOW, just leave the workaround. It has no actual cost, and the gcc bug > wasn't obviously fully fixed. There are apparently very few users of > "asm goto" (probably partly because of the limitations of it, > particularly the "no outputs"). > > Linus > Hello Linus. Agree with you that a bit more defensive approach is reasonable, mainly because of the actual cost. Thus, I send updated version of the patch which just removes unrelated GCC 4.x branch comments. Thanks, Martin --------------000902010403090201080709 Content-Type: text/x-patch; name="0001-compiler-gcc5-Remove-comments-related-to-GCC-4.x-bra.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename*0="0001-compiler-gcc5-Remove-comments-related-to-GCC-4.x-bra.pa"; filename*1="tch" >From 9db00c78af98a26685d3e0034d26962167441070 Mon Sep 17 00:00:00 2001 From: mliska Date: Wed, 15 Apr 2015 10:55:14 +0200 Subject: [PATCH 1/2] compiler/gcc5: Remove comments related to GCC 4.x branch. Signed-off-by: Martin Liska --- include/linux/compiler-gcc5.h | 8 -------- 1 file changed, 8 deletions(-) diff --git a/include/linux/compiler-gcc5.h b/include/linux/compiler-gcc5.h index efee493..abb03b8 100644 --- a/include/linux/compiler-gcc5.h +++ b/include/linux/compiler-gcc5.h @@ -12,10 +12,6 @@ like BUG(), printk(), panic() etc. [but let's keep them for now for older compilers] - Early snapshots of gcc 4.3 don't support this and we can't detect this - in the preprocessor, but we can live with this because they're unreleased. - Maketime probing would be overkill here. --------------000902010403090201080709--