From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 3336 invoked by alias); 13 Jan 2012 18:40:20 -0000 Received: (qmail 3267 invoked by uid 22791); 13 Jan 2012 18:40:18 -0000 X-SWARE-Spam-Status: No, hits=-2.8 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,TW_NV 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; Fri, 13 Jan 2012 18:40:05 +0000 From: "johnvb at broadcom dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/51709] armv7 target is not using unaligned access to packed fields sometimes (halfwords, loads?) Date: Fri, 13 Jan 2012 18:59:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: enhancement X-Bugzilla-Who: johnvb at broadcom dot com X-Bugzilla-Status: NEW 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: 2012-01/txt/msg01541.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51709 --- Comment #5 from John A. Van Boxtel 2012-01-13 18:39:43 UTC --- Sorry about not understanding CS vs GNU release numbering and time relationship. I now understand that CS versions may precede introduction into the GNC source. I will also try to work with CS on reporting the bug. I noticed this bug was listed as a code generation enhancement which I could understand in a strict sense, i.e. the code generated works. But given that the compiler does create unaligned access to half words sometimes and in armv7, there is no unaligned restrictions on normal half (or full) word access, this seems like a significant code geneation issue for armv7 and makes one wonder if the root cause might be more serious. Constrast this with an architecture like x86 where unaligned access has always been legal but if somehow the code generator used byte acesses, shifts and and/or's to access (half) words. This would be view as pretty "buggy". Bottom line: I am just trying to make sure that the "enhancement" attribute doesn't disqualify this from the current release cycle. From that point of view this seems like a bug to be fixed, not a future enhancement request. Regards, John A. Van Boxtel