From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7549 invoked by alias); 16 Aug 2011 07:25:40 -0000 Received: (qmail 7535 invoked by uid 22791); 16 Aug 2011 07:25:39 -0000 X-SWARE-Spam-Status: No, hits=-2.9 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 16 Aug 2011 07:25:24 +0000 From: "mikpe at it dot uu.se" To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/50065] -Os, -O2, -O3 optimization breaks LD/ST ordering on 32-bit SPARC Date: Tue, 16 Aug 2011 07:29:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: rtl-optimization X-Bugzilla-Keywords: X-Bugzilla-Severity: major X-Bugzilla-Who: mikpe at it dot uu.se X-Bugzilla-Status: RESOLVED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2011-08/txt/msg01400.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50065 --- Comment #10 from Mikael Pettersson 2011-08-16 07:24:48 UTC --- (In reply to comment #9) > > Regarding the spinlock_unlock in linux, the regular arch_spin_unlock is > > implemented with a single inline assembly. That will prevent the memory > > reordering in C. However, for the 32-bit port the arch_write_unlock is still > > defined as the following without a memory barrier in > > arch/sparc/include/asm/spinlock_32.h > > > > #define arch_write_unlock(rw) do { (rw)->lock = 0; } while(0) > > > > OTH, the 64-bit implemention is ok. Or did I miss something here. > > Anyway, I think this is a separated issue from this thread. > > The discrepancy is a little surprising, indeed. That was a bug in the sparc32 Linux kernel. I sent a patch yesterday to fix it.