From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 10673 invoked by alias); 27 Feb 2012 21:09:02 -0000 Received: (qmail 10665 invoked by uid 22791); 27 Feb 2012 21:09:02 -0000 X-SWARE-Spam-Status: No, hits=-2.8 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; Mon, 27 Feb 2012 21:08:49 +0000 From: "marc.glisse at normalesup dot org" To: gcc-bugs@gcc.gnu.org Subject: [Bug c/52381] asm goto output operands diagnostics Date: Mon, 27 Feb 2012 21:13:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c X-Bugzilla-Keywords: diagnostic X-Bugzilla-Severity: normal X-Bugzilla-Who: marc.glisse at normalesup dot org 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: 2012-02/txt/msg02623.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52381 --- Comment #2 from Marc Glisse 2012-02-27 21:08:44 UTC --- (In reply to comment #1) > I don't think asm goto was designed to contain more than a computed jump > instruction. And I don't know how reliably we could allocate registers > for outputs on the multiple outgoing edges. > > So, it's definitely by design. Note that if output was only reliable on the fall-through path, it would already be useful. It may not have to be all-edges-or-nothing (or it may have to, I don't know enough). Although that could be confusing... > Confirmed for the diagnostic issue. Thanks. While I am asking, I guess that since asm goto involves control flow it never gets reordered (as opposed to regular asm), but if someone feels like adding a sentence with this guarantee to the doc it would be helpful too.