From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30500 invoked by alias); 1 Dec 2011 09:22:43 -0000 Received: (qmail 30491 invoked by uid 22791); 1 Dec 2011 09:22:42 -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; Thu, 01 Dec 2011 09:22:27 +0000 From: "rguenther at suse dot de" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/50325] [4.7 Regression] 76 new fails with rev. 177691 Date: Thu, 01 Dec 2011 09:22:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: middle-end X-Bugzilla-Keywords: X-Bugzilla-Severity: critical X-Bugzilla-Who: rguenther at suse dot de X-Bugzilla-Status: REOPENED X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.7.0 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: 2011-12/txt/msg00020.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50325 --- Comment #22 from rguenther at suse dot de 2011-12-01 09:22:19 UTC --- On Thu, 17 Nov 2011, krebbel at gcc dot gnu.org wrote: > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50325 > > --- Comment #14 from Andreas Krebbel 2011-11-17 15:23:26 UTC --- > As the tests from Ian Sandoe and Dominique d'Humieres show, the Darwin/AIX > regressions disappear when limiting the extract_bit_field invocation to > fieldmode == BLKmode (as it was in the "Experimental fix" attached to the > bugzilla). > > But I'm not sure this is the right fix. In general also the other modes need > correct handling here. If the correct extraction of the source operand really > depends on things like function arg padding the handling in store_bit_field is > doomed to be incomplete. > > Richard, could you please have a look! Well, store_bit_field is supposed to do generic memory fiddling, dependency on function arg padding is unwanted - and thus such dependency has to be reflected by argument adjustments in the caller. [I can smell some weirdness we might have here though, but surely latent - if you have such argument (small C testcase I can look at with a cross?), take its address and perform aggregate assignment through a pointer - does that still work? Thus, does the memory layout of s and q in foo (struct S s) { struct S q; } really differ?