From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1309 invoked by alias); 7 Aug 2007 22:41:29 -0000 Received: (qmail 32074 invoked by uid 48); 7 Aug 2007 22:41:20 -0000 Date: Tue, 07 Aug 2007 22:41:00 -0000 Message-ID: <20070807224120.32072.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug tree-optimization/32544] gcc 4.2.1 miscompiles Mesa's r300 DRI driver with -ftree-vrp In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "pixel at mandriva dot com" 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: 2007-08/txt/msg00486.txt.bz2 ------- Comment #6 from pixel at mandriva dot com 2007-08-07 22:41 ------- more info: the tree-vrp issue is raised by ivopts pass: without ivopts: D.1541_13 = 3 - i_31; D.1542_14 = (unsigned int) D.1541_13; D.1543_15 = D.1542_14 * 4; D.1544_16 = (int *) D.1543_15; with ivopts: D.1607_62 = (int *) i_31; D.1608_63 = D.1607_62 * -4B; D.1544_64 = D.1608_63 + 12B; D.1544_16 = D.1544_64; vrp finds that D.1608_63 is 0, and so replaces D.1544_64 with 12 D.1607_62 = (int *) i_31; D.1608_63 = D.1607_62 * -4B; D.1544_64 = D.1608_63 + 12B; D.1544_16 = D.1544_64; -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32544