From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8855 invoked by alias); 19 Feb 2007 12:57:23 -0000 Received: (qmail 8764 invoked by uid 48); 19 Feb 2007 12:56:58 -0000 Date: Mon, 19 Feb 2007 12:57:00 -0000 Message-ID: <20070219125658.8763.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug tree-optimization/30840] [4.3 Regression] ice for legal code with flags -O3 -fno-strict-aliasing In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "rguenth at gcc dot gnu dot org" 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: 2007-02/txt/msg02193.txt.bz2 ------- Comment #5 from rguenth at gcc dot gnu dot org 2007-02-19 12:56 ------- We can also simply check before the fact like Index: tree-ssa-ccp.c =================================================================== *** tree-ssa-ccp.c (revision 122127) --- tree-ssa-ccp.c (working copy) *************** visit_assignment (tree stmt, tree *outpu *** 1212,1218 **** && operand_equal_p (nval->mem_ref, rhs, 0)) val = *nval; else ! val = evaluate_stmt (stmt); } else /* Evaluate the statement. */ --- 1212,1226 ---- && operand_equal_p (nval->mem_ref, rhs, 0)) val = *nval; else ! { ! val = evaluate_stmt (stmt); ! /* We need to be careful not to drop back to UNDEFINED from ! VARYING. This can happen because we only re-process the ! first virtual operand of a store. */ ! if (val.lattice_val == UNDEFINED ! && get_value (lhs)->lattice_val > UNDEFINED) ! val.lattice_val = VARYING; ! } } else /* Evaluate the statement. */ still not simulating the ssa edges for the other virtual operands does not seem to be the best approach. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30840