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From: "rguenth at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/37868] code that breaks TBAA is misoptimized even with -fno-strict-aliasing Date: Sat, 18 Oct 2008 22:44:00 -0000 [thread overview] Message-ID: <20081018224254.29308.qmail@sourceware.org> (raw) In-Reply-To: <bug-37868-15165@http.gcc.gnu.org/bugzilla/> ------- Comment #4 from rguenth at gcc dot gnu dot org 2008-10-18 22:42 ------- 4.3 is broken because PTA figures D.1187_2 = { x.a } from the constraints x.0_1 = &x D.1187_2 = x.0_1 + 64 because the 4.3 branch doesn't have the PTA fixes, in particular /* If the found variable is not exactly at the pointed to result, we have to include the next variable in the solution as well. Otherwise two increments by offset / 2 do not result in the same or a conservative superset solution. */ if (temp->offset != curr->offset + rhsoffset && temp->next != NULL) { struct constraint_expr c2; c2.var = temp->next->id; c2.type = ADDRESSOF; c2.offset = 0; VEC_safe_push (ce_s, heap, *results, &c2); } see rev. 137573: 2008-07-07 Richard Guenther <rguenther@suse.de> + * tree-ssa-structalias.c (struct variable_info): Add is_full_var flag. + (new_var_info): Set it to false. + (solution_set_add): Correctly handle pointers outside a var and + inside a field. + (type_safe): Treat variables with is_full_var properly. + (do_sd_constraint): Likewise. + (do_ds_constraint): Likewise. + (process_constraint): Remove zeroing offset for !use_field_sensitive. + (get_constraint_for_ptr_offset): New function. + (get_constraint_for_component_ref): For addresses at least include + the last field of the variable. Handle is_full_vars properly. + (get_constraint_for_1): Factor common code, handle POINTER_PLUS_EXPR. + (handle_ptr_arith): Remove. + (find_func_aliases): Simplify assignment handling. + (create_function_info_for): For parameter and result varinfos set + is_full_var flag. + (create_variable_info_for): Set is_full_var flag whenever we + just created a single varinfo for a decl. + (init_alias_vars): Initialize use_field_sensitive from + max-fields-for-field-sensitive parameter. -- rguenth at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed|0 |1 Keywords| |wrong-code Last reconfirmed|0000-00-00 00:00:00 |2008-10-18 22:42:54 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37868
next prev parent reply other threads:[~2008-10-18 22:44 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2008-10-18 18:17 [Bug tree-optimization/37868] New: code that doesn't " edwintorok at gmail dot com 2008-10-18 18:30 ` [Bug tree-optimization/37868] code that " sabre at nondot dot org 2008-10-18 18:58 ` rguenth at gcc dot gnu dot org 2008-10-18 22:36 ` rguenth at gcc dot gnu dot org 2008-10-18 22:44 ` rguenth at gcc dot gnu dot org [this message] 2008-10-22 11:48 ` [Bug tree-optimization/37868] [4.3 Regression] " rguenth at gcc dot gnu dot org 2008-10-22 13:50 ` rguenth at gcc dot gnu dot org 2008-11-03 11:29 ` jakub at gcc dot gnu dot org 2008-11-07 12:51 ` rguenth at gcc dot gnu dot org 2008-11-20 12:14 ` rguenth at gcc dot gnu dot org 2008-11-20 12:15 ` rguenth at gcc dot gnu dot org 2008-11-20 12:28 ` rguenth at gcc dot gnu dot org
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