From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 523 invoked by alias); 28 Aug 2015 15:05:09 -0000 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 Received: (qmail 131010 invoked by uid 48); 28 Aug 2015 15:05:04 -0000 From: "jiwang at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/67305] [6 Regression] gcc.c-torture/compile/20121027-1.c ICE Date: Fri, 28 Aug 2015 15:05:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: rtl-optimization X-Bugzilla-Version: 6.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: jiwang at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 6.0 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2015-08/txt/msg01952.txt.bz2 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67305 --- Comment #3 from Jiong Wang --- >>From the tree dump .pre, I understand the tree shape is improved as we deleted one redundant Phi, but we also noticed there is one regression, we are turning _6 = bl_20 >> 6 into something like: _5 = c_16 / 64; While for signed division, we need to generate extra check instruction sequences, although rtl passes should handle this, but seems to me this is still a regression, Richard, is it because we have lost some range info after your patch? the division was turned into right shift after vrp pass. Anyway, we also need to figure out why after this division change, the rtl pass crash.