From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14212 invoked by alias); 28 Nov 2012 15:16:23 -0000 Received: (qmail 13988 invoked by uid 48); 28 Nov 2012 15:16:01 -0000 From: "rguenth at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/55481] [4.8 regression] -O2 generates a wrong-code infinite loop in C++Benchmark's simple_types_constant_folding int8 xor test Date: Wed, 28 Nov 2012 15:16:00 -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: 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: 4.8.0 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: 2012-11/txt/msg02751.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55481 --- Comment #10 from Richard Biener 2012-11-28 15:16:00 UTC --- Caused by 2012-06-27 Richard Guenther PR middle-end/53676 * tree-chrec.c (chrec_convert_1): Represent truncation to a type with undefined overflow as truncation to an unsigned type converted to the type with undefined overflow. * tree-scalar-evolution.c (interpret_rhs_expr): For computing the scalar evolution of a truncated widened operation avoid looking at the non-existing evolution of the widened operation result.