From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 25470 invoked by alias); 19 Jan 2012 10:06:58 -0000 Received: (qmail 25461 invoked by uid 22791); 19 Jan 2012 10:06:57 -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, 19 Jan 2012 10:06:44 +0000 From: "rguenth at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/51895] [4.7 Regression] ICE in simplify_subreg Date: Thu, 19 Jan 2012 10:16:00 -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: ice-on-valid-code X-Bugzilla-Severity: normal X-Bugzilla-Who: rguenth at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.7.0 X-Bugzilla-Changed-Fields: Status Last reconfirmed Target Milestone Ever Confirmed 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/msg02097.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51895 Richard Guenther changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2012-01-19 Target Milestone|--- |4.7.0 Ever Confirmed|0 |1 --- Comment #3 from Richard Guenther 2012-01-19 10:06:38 UTC --- (In reply to comment #2) > This starts with eipa_sra. It changes a S argument (which has TImode > TYPE_MODE) into char [9] (with BLKmode)) and then on both caller and callee > side we have on one side a BLKmode type and on the other side a BLKmode MEM_REF > with pointer to TImode on the second MEM_REF operand. > I wonder why it does this, instead of just using type S, and if it really has > to for some reason, why it can't at least make sure it has the same TYPE_MODE. > Changing a TImode argument to a BLKmode argument doesn't look at least like a > good optimization. > > Or the bug is in the MEM_REF expansion, which expands a BLKmode MEM_REF into a > TImode reg: > bftype = TREE_TYPE (base); > if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode) > bftype = TREE_TYPE (exp); > return expand_expr (build3 (BIT_FIELD_REF, bftype, > base, > TYPE_SIZE (TREE_TYPE (exp)), > bit_offset), > target, tmode, modifier); > base here is TImode (x PARM_DECL), but exp is BLKmode, so this returns a TImode > pseudo. Shouldn't it store it into a BLKmode temporary and return that MEM > instead? Using a BIT_FIELD_REF looked most convenient. Using extract_bit_field may also be an option (which I suppose is what the above ends up doing?)