From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755950AbaHFKXy (ORCPT ); Wed, 6 Aug 2014 06:23:54 -0400 Received: from unicorn.mansr.com ([81.2.72.234]:36689 "EHLO unicorn.mansr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755912AbaHFKXw convert rfc822-to-8bit (ORCPT ); Wed, 6 Aug 2014 06:23:52 -0400 From: =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= To: Jakub Jelinek Cc: Linus Torvalds , "Frank Ch. Eigler" , Josh Boyer , Greg Kroah-Hartman , Linux Kernel Mailing List , stable , Michel =?iso-8859-1?Q?D=E4nzer?= , Markus Trippelsdorf , Josh Stone Subject: Re: [PATCH 3.15 33/37] Fix gcc-4.9.0 miscompilation of load_balance() in scheduler References: <20140730014827.565626091@linuxfoundation.org> <20140730014829.344302554@linuxfoundation.org> <20140730065312.GA1652@laptop.redhat.com> <20140805210728.GH13858@redhat.com> <20140806081441.GZ7393@tucnak.redhat.com> Date: Wed, 06 Aug 2014 11:23:47 +0100 In-Reply-To: <20140806081441.GZ7393@tucnak.redhat.com> (Jakub Jelinek's message of "Wed, 6 Aug 2014 10:14:41 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jakub Jelinek writes: > There have been several man-years of work to get from the 25% var coverage > to 67%, several DWARF extensions (most of them to be available in DWARF5 or > work in progress on that) and with -fno-var-tracking-assignments that is > just returned to the old state. This is a typical "but look at all the work we've put in, it *has* to work" argument. As always, it is completely without merit. >> In other words, anybody who relies on it has already learnt to work >> around it. Or, more likely, there just isn't anybody who relies on it. >> >> I don't understand how you guys can be so cavalier about a compiler >> bug that has already resulted in actual real problems. You bring up > > I have no problem with a -fno-var-tracking-assignments workaround for > compilers that have the PR61801 wrong-code bug. Are there any that with reasonable confidence do not? -- Måns Rullgård mans@mansr.com From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= To: Jakub Jelinek Cc: Linus Torvalds , "Frank Ch. Eigler" , Josh Boyer , Greg Kroah-Hartman , Linux Kernel Mailing List , stable , Michel =?iso-8859-1?Q?D=E4nzer?= , Markus Trippelsdorf , Josh Stone Subject: Re: [PATCH 3.15 33/37] Fix gcc-4.9.0 miscompilation of load_balance() in scheduler References: <20140730014827.565626091@linuxfoundation.org> <20140730014829.344302554@linuxfoundation.org> <20140730065312.GA1652@laptop.redhat.com> <20140805210728.GH13858@redhat.com> <20140806081441.GZ7393@tucnak.redhat.com> Date: Wed, 06 Aug 2014 11:23:47 +0100 In-Reply-To: <20140806081441.GZ7393@tucnak.redhat.com> (Jakub Jelinek's message of "Wed, 6 Aug 2014 10:14:41 +0200") Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: Jakub Jelinek writes: > There have been several man-years of work to get from the 25% var coverage > to 67%, several DWARF extensions (most of them to be available in DWARF5 or > work in progress on that) and with -fno-var-tracking-assignments that is > just returned to the old state. This is a typical "but look at all the work we've put in, it *has* to work" argument. As always, it is completely without merit. >> In other words, anybody who relies on it has already learnt to work >> around it. Or, more likely, there just isn't anybody who relies on it. >> >> I don't understand how you guys can be so cavalier about a compiler >> bug that has already resulted in actual real problems. You bring up > > I have no problem with a -fno-var-tracking-assignments workaround for > compilers that have the PR61801 wrong-code bug. Are there any that with reasonable confidence do not? -- M�ns Rullg�rd mans@mansr.com