From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 95393 invoked by alias); 13 Apr 2015 04:50:42 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 94770 invoked by uid 89); 13 Apr 2015 04:49:28 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mail-pa0-f43.google.com Received: from mail-pa0-f43.google.com (HELO mail-pa0-f43.google.com) (209.85.220.43) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Mon, 13 Apr 2015 04:49:10 +0000 Received: by pacyx8 with SMTP id yx8so90015885pac.1 for ; Sun, 12 Apr 2015 21:49:00 -0700 (PDT) X-Received: by 10.66.222.72 with SMTP id qk8mr23325196pac.7.1428900540460; Sun, 12 Apr 2015 21:49:00 -0700 (PDT) Received: from bubble.grove.modra.org (CPE-58-160-155-134.oycza5.sa.bigpond.net.au. [58.160.155.134]) by mx.google.com with ESMTPSA id x9sm5742504pbt.68.2015.04.12.21.48.59 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 12 Apr 2015 21:48:59 -0700 (PDT) Received: by bubble.grove.modra.org (Postfix, from userid 1000) id 5ECC2EA017E; Mon, 13 Apr 2015 14:18:55 +0930 (ACST) Date: Mon, 13 Apr 2015 04:50:00 -0000 From: Alan Modra To: Richard Biener Cc: Jeff Law , GCC Patches Subject: Re: Fix for PRs 36043, 58744 and 65408 Message-ID: <20150413044855.GB18863@bubble.grove.modra.org> Mail-Followup-To: Richard Biener , Jeff Law , GCC Patches References: <20150314130238.GD16488@bubble.grove.modra.org> <55088069.3010802@redhat.com> <20150318042208.GD24573@bubble.grove.modra.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) X-IsSubscribed: yes X-SW-Source: 2015-04/txt/msg00544.txt.bz2 On Wed, Mar 18, 2015 at 12:12:17PM +0100, Richard Biener wrote: > On Wed, Mar 18, 2015 at 5:22 AM, Alan Modra wrote: > > On Tue, Mar 17, 2015 at 01:28:41PM -0600, Jeff Law wrote: > >> On 03/14/2015 07:02 AM, Alan Modra wrote: > >> > PR target/65408 > >> > PR target/58744 > >> > PR middle-end/36043 > >> > * calls.c (load_register_parameters): Don't load past end of > >> > mem unless suitably aligned. > >> I think this is probably a stage1 item. Richi, Jakub, Joseph, do any of you > >> think we should try to push this into gcc-5? > > > > Some (severity) background to PR65408. The bug came from SAP HANA > > (en.wikipedia.org/wiki/SAP_HANA), a crash that happens on powerpc64 > > and powerpc64le. aarch64 would also be susceptible to the crash since > > it also loads 16 bytes for the 12-byte struct. x86_64 only loads 12 > > bytes (i386.c:construct_container generates a parallel with a DImode > > and SImode load). However the underlying bug is there and hits x86_64 > > too for the pr58744 and pr36043 testcases.. > > It's a very very very old bug though. I'd be interested in any odd > code-generation difference for compiling, say, the linux kernel > (you _can_ get quite ugly code generated because of this fix). Yes, all those byte loads.. As far as the kernel goes, x86_64 shows some differences in calls to rgb_{fore,back}ground in drivers/tty/vt/vt.c. Both before and after look ugly to me. :) 4d73: 8b 82 24 02 00 00 mov 0x224(%rdx),%eax 4d79: 48 89 df mov %rbx,%rdi 4d7c: 41 83 c4 04 add $0x4,%r12d 4d80: 88 45 b2 mov %al,-0x4e(%rbp) 4d83: 8b 82 28 02 00 00 mov 0x228(%rdx),%eax 4d89: 88 45 b3 mov %al,-0x4d(%rbp) 4d8c: 8b 82 2c 02 00 00 mov 0x22c(%rdx),%eax 4d92: 88 45 b4 mov %al,-0x4c(%rbp) 4d95: 48 8b 75 b2 mov -0x4e(%rbp),%rsi 4d99: e8 00 00 00 00 callq vs. 4d73: 8b 82 24 02 00 00 mov 0x224(%rdx),%eax 4d79: 0f b6 b2 2c 02 00 00 movzbl 0x22c(%rdx),%esi 4d80: 48 89 df mov %rbx,%rdi 4d83: 41 83 c4 04 add $0x4,%r12d 4d87: 88 45 b2 mov %al,-0x4e(%rbp) 4d8a: 8b 82 28 02 00 00 mov 0x228(%rdx),%eax 4d90: 48 c1 e6 10 shl $0x10,%rsi 4d94: 88 45 b3 mov %al,-0x4d(%rbp) 4d97: 0f b7 45 b2 movzwl -0x4e(%rbp),%eax 4d9b: 48 09 c6 or %rax,%rsi 4d9e: e8 00 00 00 00 callq Is the patch OK for stage1? -- Alan Modra Australia Development Lab, IBM