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From: "hubicka at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/45791] Missed devirtualization Date: Sun, 26 Sep 2010 06:02:00 -0000 [thread overview] Message-ID: <20100926060200.aRbf4mATTgMIydrXRsbuCA2o0k8iF4UbjyPiECWYedk@z> (raw) In-Reply-To: <bug-45791-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45791 --- Comment #5 from Jan Hubicka <hubicka at gcc dot gnu.org> 2010-09-25 22:17:41 UTC --- Another testcase where we devirtualize via folding is: // { dg-do assemble } // { dg-options "-g -O2" } // Copyright (C) 1999 Free Software Foundation, Inc. // Contributed by Nathan Sidwell 21 Nov 1999 <nathan@acm.org> // This causes assember relocation errors struct X { virtual ~X () {} }; struct Y { Y (){}; }; void foo () { X *x = new X; x->~X (); Y ys[2]; } compiled with -O2 we get x_3 = operator new (8); # DEBUG this => x_3 x_3->_vptr.X = &_ZTV1X[2]; # DEBUG x => x_3 D.2142_7 = (int (*__vtbl_ptr_type) (void)) __comp_dtor ; OBJ_TYPE_REF(D.2142_7;x_3->0) (x_3); that gets folded only in ccp3. We need FRE to fold: x_3->_vptr.X = &_ZTV1X[2]; # DEBUG x => x_3 D.2141_6 = &_ZTV1X[2]; D.2142_7 = *D.2141_6; OBJ_TYPE_REF(D.2142_7;x_3->0) (x_3); into x_3 = operator new (8); # DEBUG this => x_3 x_3->_vptr.X = &_ZTV1X[2]; # DEBUG x => x_3 D.2141_6 = x_3->_vptr.X; D.2142_7 = *D.2141_6; OBJ_TYPE_REF(D.2142_7;x_3->0) (x_3);
next prev parent reply other threads:[~2010-09-25 22:17 UTC|newest] Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-09-25 17:28 [Bug tree-optimization/45791] New: " hubicka at gcc dot gnu.org 2010-09-25 19:50 ` [Bug tree-optimization/45791] " hubicka at gcc dot gnu.org 2010-09-26 3:33 ` hubicka at gcc dot gnu.org 2010-09-26 3:39 ` hubicka at gcc dot gnu.org 2010-09-26 6:02 ` hubicka at gcc dot gnu.org [this message] 2010-10-11 17:15 ` jamborm at gcc dot gnu.org 2010-10-11 18:40 ` jamborm at gcc dot gnu.org 2010-12-14 17:46 ` jamborm at gcc dot gnu.org 2010-12-14 23:15 ` hubicka at gcc dot gnu.org 2010-12-14 23:17 ` hubicka at gcc dot gnu.org 2010-12-14 23:35 ` jamborm at gcc dot gnu.org 2010-12-15 0:10 ` hubicka at gcc dot gnu.org 2010-12-15 0:13 ` hubicka at gcc dot gnu.org 2010-12-15 16:07 ` jamborm at gcc dot gnu.org 2014-02-24 9:44 ` matthijs at stdin dot nl 2014-09-25 20:29 ` hubicka at gcc dot gnu.org 2021-01-07 17:38 ` jamborm at gcc dot gnu.org
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